AWUS01 KWNH 112237
FFGMPD
CAZ000-120300-

Mesoscale Precipitation Discussion 0039
NWS Weather Prediction Center College Park MD
537 PM EST Wed Jan 11 2023

Areas affected...northwestern, central California

Concerning...Heavy rainfall

Valid 112237Z - 120300Z

Summary...Spots of 0.25-0.5 inch/hr rainfall rates should continue
across the discussion area through 03Z or so. A lessening of
rainfall rates is expected thereafter. An additional 1-2 inches
of rainfall are possible.

Discussion...As anticipated, a broad fetch of Pacific moisture/IVT
resulted in areas of moderate to locally heavy rainfall across the
discussion area, with rain rates ramping up locally to around 0.5
inch/hr especially after around 18Z or so. This axis of
lift/moisture will continue to persist across the area for at
least another 4-5 hours or so, with 1-1.2 inch PW values and
onshore mid-level providing lift/ascent for continued convective
development. These rainfall rates are also continuing atop areas
that have received 10-20+ inches of rainfall in the past 2-2.5
weeks along with widespread flood/flash flood impacts (some of
which are continuing). The locally heavier rainfall rates could
exacerbate ongoing impacts especially in/near sensitive or already
flooded areas.

Models (CAMs particularly) indicate that the ongoing regime should
continue to produce locally heavy rainfall (and 1-2 inch totals)
through 03Z or so. Thereafter, backing mid-level flow (in tandem
with a deepening cyclone over northeastern Pacific Waters) will
result in a northward shift of the heaviest of rainfall rates into
far northwestern California and perhaps southern Oregon.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5eavgLcxxcJD2Weefe7JIAS3sNO4waRC33Ohgm8GYyjYCDVy3H8dzyFJ0A1qpRBl1dP6= arDcLYiIbqmlrYrsl-yOWmQ$ for graphic product...

ATTN...WFO...EKA...HNX...MFR...MTR...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41462399 40552209 38412159 37092123 36472144=20
36472237 37542327 39082414 40012461 41072472=20 =20=20=20=20=20=20=20=20=20=20=20=20

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AWUS01 KWNH 141501
FFGMPD
CAZ000-142230-

Mesoscale Precipitation Discussion 0041
NWS Weather Prediction Center College Park MD
1000 AM EST Sat Jan 14 2023

Areas affected...Northern and Central CA

Concerning...Heavy rainfall...Flash flooding possible

Valid 141500Z - 142230Z

SUMMARY...Heavy rains will continue to overspread northern and
central CA today as the next in a series of West Coast storms
systems arrives. This will facilitate areas of f, and potentially
localized flash flooding given the wet/saturated soil conditions.

DISCUSSION...Surface observations and satellite imagery show a
strong storm system offshore of the the West Coast continuing to
advance east which is driving a cold front toward the coastal
ranges of central and northern CA. A southwest low-level jet of 40
to 50 kts ahead of the front is favoring strong warm air advection
and moisture transport into the coastal terrain and inland across
the interior valleys and foothills of the Sierra Nevada.

Already ongoing IVT values of as much as 500 to 700 kg/m/s with an
orientation largely orthogonal to the terrain is fostering
widespread heavy rainfall with rates across the coastal ranges
north and south of the Bay Area in the 0.25" to 0.50" range. Radar
imagery shows heavier rains also becoming increasingly noted
across portions of the Sacramento Valley as these higher IVT
values punch inland with the low-level jet.

The Bay Area should tend to be the focus for the heaviest rains
over the next few hours along with the adjacent coastal ranges.
However, increasing IVT values and forcing will spread farther
down the coast, and especially with an emphasis on Monterey, San
Luis Obispo, and Santa Barbara counties going through 21Z. From
the Bay Area south down across the Santa Cruz, Santa Lucia, and
eventually the Santa Ynez mountain mountains, rainfall rates
should increase to locally around 0.75"/hour.

Similar rates are expected to impact the foothills of the Sierra
Nevada east of the Central Valley as well, and all of these rains
today are expected to foster additional runoff and flooding
concerns giving the very wet/saturated antecedent conditions. Some
localized flash flooding will be possible with some of these rates
where they overlap with some of the area burn scar locations.

Gradually the offshore cold front will edge inland going through
the afternoon hours, and this will allow for the rains to begin to
become more showery in nature for northern CA, but areas farther
south closer to the Transverse Range will continue to see rains
along and ahead of the front lasting for much of the day.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!44wiEk2y7w7K2rs3alTXGYA46MQH0OKQ_jVz6l2H2vL8fzDbGB4lZOkJmavgzmHA3NzB= XXBQhlDQsXAe4J7G7PUk9LI$ for graphic product...

ATTN...WFO...EKA...HNX...LOX...MFR...MTR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41522338 41112240 40442162 39032058 37741913=20
36771853 36481920 37322042 37422081 37052115=20
35872077 35001970 34511937 34221985 34182037=20
34522071 35582134 36902235 38042310 38962390=20
40202445 41272427=20

=3D =3D =3D
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AWUS01 KWNH 241522
FFGMPD
TXZ000-242100-

Mesoscale Precipitation Discussion 0047
NWS Weather Prediction Center College Park MD
1022 AM EST Tue Jan 24 2023

Areas affected...Mid to Upper Texas Coastal Plain...

Concerning...Heavy rainfall...Flash flooding possible

Valid 241520Z - 242100Z

SUMMARY...Increasing convective development and potential for slow
moving, efficient rainfall producing cells. Downstream
development along warm front may also allow for some repeating and
therefore localized flash flooding may be possible with 2-4"
totals in short (1-3hrs) duration.

DISCUSSION...GOES-E WV depicts a strong compact closed low over
the Western TX panhandle pressing eastward with broad favorable
diffluent upper level jet pattern with dual right entrance/left
exit jet structure out of N TX/OK and across northeast Mexico into
far south TX. This is providing a dynamic surface cyclogenesis
across central TX this morning with strong emergence of western
Gulf higher moist/unstable air pressing a warm front northward
from west of COT near the low to BEA to south of VCT and DVY. Low
70s T with mid to upper 60s Tds are supporting increasing unstable
air, but given the approaching height-falls the western Gulf LLJ
has strengthened to over 50kts per CRP/EWX VWP overriding the
frontal zone. WV suite denotes the edge of the best height-falls
tightening on the western side of the jet likely to increase deep
layer moisture convergence to support growing vertical nature to
the showers in the area. Given the strength of flux convergence
and increasing MUCAPE values of 1000-1500 J/kg, rainfall
efficiency should support intense rates with 1.5" toward 16-17z
increasing slowly to about 2" as the cells/convergence move
eastward into the core of the moisture axis denoted by TPW of
1.6-1.7". Cell motions will be more north-northwest in the line
with slow eastward propagation allowing for some increased
duration with quick 1.5-2.5" in a hour and spots of 2-4" possible
over 2-3hrs mainly near the warm front near the I-10 corridor east
of San Antonio. Intensity of rates will decrease toward the north
as isentropic ascent becomes more elevated.

Further east, strong surface convergence and slow northward
movement of the warm front should allow for scattered cells with
isolated more intense rain-rates. Individually they are less
likely to induce rainfall rates/totals to induce flooding
concerns, with exception in urban locales. However, 1-2" totals
with these scattered cells will prime the soils ahead of the main
line as it progresses eastward. The intersection/repeat nature
will support the greatest risk of rainfall over 3-4" as supported
by a bulk of the hi-res CAM guidance providing some confidence.=20
However, there are some guidance solutions as great at 5-6" with
the FV3CAM and Candian Regional and while this is not favored,
ideal setup/training may allow for this much lower potential given
the strong dynamics, warm front placement to the Gulf to at least
mention the very low end possibility of it to occur. If it were
to manifest, it would very likely be south of I-10 and east toward
Galveston Bay given the nature of convection training and
reinforcing and locking the frontal zone in place for a longer
duration.

Soil conditions are quite dry for the area both in depth and
relative to the seasonal average, given the intensity of the rates
this may actually reduce infiltration with increased run-off, but
more likely the vast majority of the area should absorb better
than run-off. Given the rates, totals of 2-4" locally higher,
flash flooding is considered possible through the late morning
into the afternoon.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7Y4aenU4knzwWloMXaLSD4X56sXwXpHHTf5y4xaawbDWt_ijhAEQZjgEecqTZfqi9rt5= Vin0oiUif_0DD-LszUXCDoQ$ for graphic product...

ATTN...WFO...CRP...EWX...FWD...HGX...

ATTN...RFC...WGRFC...NWC...

LAT...LON 31189646 31069539 30409470 29839474 29319539=20
28889633 28589727 28499766 28419829 28849839=20
29709810 30389767=20

=3D =3D =3D
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AWUS01 KWNH 241952
FFGMPD
LAZ000-TXZ000-250110-

Mesoscale Precipitation Discussion 0048
NWS Weather Prediction Center College Park MD
251 PM EST Tue Jan 24 2023

Areas affected...Upper TX Coast into Southwest LA...

Concerning...Heavy rainfall...Flash flooding possible

Valid 241950Z - 250110Z

SUMMARY...Possible isolated incidents of flash flooding continue
in vicinity of the I-10 corridor as the surface low deepens and
shifts east-northeast this evening into overnight ...

DISCUSSION...RADAR Mosaic depicts strong thunderstorms in
proximity to the rapidly deepening surface low near DWH along the
warm front to the east across the northern Houston Metro-suburbs
with convergence bands along the cold front and western gulf
confluence trof intersecting near Fort Bend county. Strong
surface winds in the 20-25kt range with ~45-60 degrees of
convergence of upper 60s to low 70s Tds, combined with slowly
veering 925-850mb moisture stream out of the western Gulf across
the low is supporting very strong ascent and moisture flux to
support 2.5"/hr rates, with 2.77" reported at DWH in the last
hour. Mid to upper level RAP analysis supported by GOES-E WV
depicts the nose of best diffluence aloft at this weak inflection
upstream of the surface low, showing signs of outpacing the best
wave. This should support a few more hours of this strong
convergence with similar rates across the Houston Metro into far
SE TX. Thereafter, this inflection/best dynamic ascent will shift
north and east of the surface wave and LLJ will veer narrowing the
warm sector/onshore flow.

While this restriction in warm sector is sizable, remaining
unstable air in proximity to the warm front that is slowly lifting
into SW LA will still support 1.5-2"/hr rates but cells should
become more progressive reducing time window for southwest to
northeast moving cells to train. As such, totals will diminish a
bit toward the 2-3" range verses the 3-4" range expected over SE
TX. HRRR 15 & 18z runs help to confirm this by depicting 15
minute totals still in the 1-1.25" range and moving quickly to
result in maybe 30 minutes of intense rainfall. This should
result in highly localized high run-off, but may not expand in a
broad enough area to pose larger areal incidents in neighboring
watersheds for all but low-end and urban style flash flooding.=20
This should further diminishing after 01-02z into south-central
LA, as warm sector will likely be narrowed further with
instability only remaining as MUCAPE isentropically ascended
though the veering 850mb LLJ. The HRRR has been performing well
over the last few runs, generally a little slow but faster than
normal bias, providing additional confidence to its solution
unfolding over the next few hours.

Given recently dry soil conditions per LIS data from NASA SPoRT,
flash flooding is considered possible, with best chances earlier
and further west, but still remain non-zero well after 23z

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7g5ypQjB1VrcktLMiMPqZBn2uXWqNoAPx3ImRTOaP0lJEa16QX7NvAaO1q6rqTvWdfVM= VX9l_F4PvizMMW7_EtfVgag$ for graphic product...

ATTN...WFO...HGX...LCH...SHV...

ATTN...RFC...LMRFC...WGRFC...NWC...

LAT...LON 31589253 30909190 29899205 29619264 29729359=20
29429465 28979589 29399640 30559558 31359428=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
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AWUS01 KWNH 250144
FFGMPD
MSZ000-LAZ000-250430-

Mesoscale Precipitation Discussion 0049
NWS Weather Prediction Center College Park MD
844 PM EST Tue Jan 24 2023

Areas affected...Portions of Louisiana and Southern Mississippi

Concerning...Heavy rainfall...Flash flooding possible

Valid 250143Z - 250430Z

SUMMARY...Possible isolated incidents of flash flooding continue
as surface low organizes and shifts east-northeast during the
evening and into the overnight.

DISCUSSION...RADAR Mosaic depicts strong thunderstorms along and
ahead of a cold front associated with an organizing area of
surface low pressure. Surface winds in the 20-25kt range with
~45-60 degrees of convergence of upper 60s to low 70s Tds,
combined with slowly veering 925-850mb moisture stream out of the
western Gulf across the low is supporting very strong ascent and
moisture flux to support localized 1 to 2 inch per hour rainfall
rates. Mid to upper level RAP analysis supported by GOES-E WV
depicts the nose of best difluence aloft at this weak inflection
upstream of the surface low, showing signs of outpacing the best
wave. This should support a few more hours of this strong
convergence with similar rates across portions of Louisiana and southern/southwestern Mississippi...at which point the
inflection/best dynamic ascent will shift north and east of the
surface wave and LLJ will veer narrowing the warm sector/onshore
flow.

This should result in highly localized high run-off, but may not
expand in a broad enough area to pose larger areal incidents in
neighboring watersheds for all but low-end and urban and small
stream type flash flooding. This should further diminishing
between 03Z and 04Z over south-central and southeast Louisiana as
warm sector continues to narrow further with instability only
remaining as MUCAPE isentropically ascended though the veering
850mb LLJ. The HRRR has been performing well over the last few
runs despite showing itself to be a bit on the slow side.=20

Bann

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4PlGOElH1UZLHQcuR_rdEuliYx4gTjIvA_3V7ddA9l--RiTU08CXrbDRiVo3m0eV1PSQ= D8kmATgnAmx3IiUMxVpdQ9k$ for graphic product...

ATTN...WFO...JAN...LCH...LIX...

ATTN...RFC...LMRFC...NWC...

LAT...LON 31989016 31598982 30869025 30279039 29899057=20
29549048 29249058 29049076 29199123 29359165=20
29599177 30879132 31679076=20

=3D =3D =3D
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AWUS01 KWNH 130412
FFGMPD
CAZ000-ORZ000-131315-

Mesoscale Precipitation Discussion 0040
NWS Weather Prediction Center College Park MD
1111 PM EST Thu Jan 12 2023

Areas affected...Redwood Coast of Southwest OR and Northwest CA...

Concerning...Heavy rainfall

Valid 130415Z - 131315Z

SUMMARY...Solid meridional Atmospheric River with very slow
eastward drift allow for increasing rainfall totals across
saturated ground conditions in NW CA and SW OR through much of the
morning hours.

DISCUSSION...BHX RADAR denoted a weak MCV lifting north parallel
to Arcata toward Crescent City along a well defined but narrow
nearly due north-south flow ahead of the cold front. This wave
was a bit more amplified that much of the guidance suite and
therefore with its passing has pressed the trailing confluence
axis a bit further east, faster exposing the upper portions of the
Lost Coast, Cape Mendocino to the stronger/deeper moisture plume
and enhanced rainfall rates. Sfc Tds and deeper layer moisture
remains a but further upstream per surface analysis and CIRA LPW
Sfc-850mb layer, so this band of rainfall should be more limited
in intensity given some sub-cloud drier air and evaporation with
rates of .15-.2" expected with some favorable orographic ascent
rates of .25-.3" across the western Lost Coast in best orthogonal
ascent to the southerly flow (given 55-60kts per BHX VWP).

CIRA LPW 850-700 layer suggest best moisture flex remains upstream
a bit west of the mouth of San Francisco Bay but will be
approaching in timing in the 7-9z time frame coincident with the
passage of subtle mid to upper level ridging as a 100+kt 3H jet
core slides north and east, exposing the area of concern to better
upper level divergence aiding upglide acceleration to the AR plume
along and ahead of the slowly approaching cold front. GOES WV
suite denotes this well in the broad broken cirrus wedge SW of the
NW CA attm. This will further tighten/strengthen moisture flux
convergence in the pre-frontal band with core of 1-1.2" Total
PWats. This will keep the Lost Coast more exposed to highest rain
rates of .5"/hr after 09z. Totals will increase fairly rapidly
given expected very slow eastward drift through the early morning
hours. Totals of 2-3" should be expected with perhaps best highly
focused totals of 4"+ possible by 15z.=20=20

While ground conditions remain highly saturated per NASA SPoRT LIS
0-40cm relative soil moisture values are 80-90% supporting most of
the rainfall to runoff further swelling well above normal river
and stream levels in the region, the rates are still probably not
high enough to induce rapid inundation/flash flooding rates given
the Redwood area is a temperate rain forest...and so MPD does not
quite rise to FF possible threshold just yet and denoted as Heavy
Rainfall/AR tag, especially even into SW OR, where some shadowing
may exist due to south to north plume orientation.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9jg9wbc58J-rGop4cxnvnWO9lMC68D1CVH4dA5KMUDx-n50wm0K1kU1VmGmjD_CJWoKN= GxtlGVtovedRU12Vxa_AtFk$ for graphic product...

ATTN...WFO...EKA...MFR...MTR...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 42802434 42672388 42122363 40622344 38922312=20
38682360 39682391 40222440 40742437 41322422=20
42492450=20

=3D =3D =3D
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AWUS01 KWNH 080351
FFGMPD
ARZ000-TXZ000-OKZ000-080900-

Mesoscale Precipitation Discussion 0055
NWS Weather Prediction Center College Park MD
1050 PM EST Tue Feb 07 2023

Areas affected...Northeast TX...Southeast OK...Ext Southwest AR...

Concerning...Heavy rainfall...Flash flooding possible

Valid 080350Z - 080900Z

SUMMARY...Persistent over-running with embedded isolated to
scattered stronger updrafts capable of repeating/training may
induce isolated incidents of low-end flash flooding into the early
morning hours across northeast TX into far southeast OK and
perhaps adjacent AR.

DISCUSSION...03z surface analysis depicts a weak wave near CRS
with well defined cold front in RADAR/convergence fields extending south-southwest toward AUS before angling more westward south of
UVA. A warm front extend ENE to JXI to ELD and into the TN
Valley. While the convergence is strong with nearly opposing
directional flow across Central TX, the front is slow to progress
eastward as upper level trof over NM remains more positive tilt
with subtle shortwave ridging across E TX into OK at this time.=20
Still, ample diffluence and proximity to right entrance to upper
level jet and FGEN support over OK/AR, the low level jet is
strengthening with 30kts expected to increase to 35-40kts through
the evening due to increased confluence of the flow (pinched from
the west and east as the prior wave exits).=20

Overall, this provides a prolonged isentropic WAA ascent pattern
maintained by strong surface based moisture convergence along the
cold front near the surface wave. Solid moisture is available and
increasing given arrival of low to mid-level moisture off the
Pacific as well as sfc to low level moisture from the Western
Gulf. Total PWATs will increase to 1.5" and while this is not
helping to increase lapse rates, the theta-E advection will
increase through the morning slowly rising instability from 500
J/kg toward 1000 J/kg. As such, convection will not be highly
focused but scattered in nature and may allow for localized areas
of maximized convergence near the surface low allowing for
back-building development along the flanking lines as more mature
cells track northward toward/across the Red River slowly weakening
with time. Rates of 1.5"/hr are possible with 15-min totals of
.5-.6" per recent HRRR runs. Given the potential for
repeating/training streets in the broader isentropic ascent
region, isolated totals of 2-3" are probable in 3-6hr period.=20

NASA SPoRT relative soil moisture values and 0-40cm percentile
values supported by 14 day AHPS precipitation anomaly values are
normal to slightly above normal from College Station to Tyler to
near Texarkana and eastward. Yet, FFG values are back to normal
and much more elevated (above 2-2.5"/hr and greater than 3"/3hrs)
which seem unlikely to be eclipsed, though the opposite is true
around I-35 into portions of Northeast TX/SE OK... where FFG
values are more in the range of potential exceedance by the
expected 2-3" totals, yet are generally at or below average for
soil moisture ratios. This adds some uncertainty to hydrological
response to the aforementioned rates and 3-6hr localized
totals...still, given dormant ground conditions, a few incidents
of flash flooding are possible through the early morning hours,
with greatest concerns along and just north of the surface low.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5YJkgRF0nP3tHbfRpAl88W2_KcCC43lRHDMFCbLxkdEZnq5Q4fFMmpG_A8zmTZu8JQfQ= CoF_txBcc2x_kOA5XD_UVKE$ for graphic product...

ATTN...WFO...FWD...LZK...OUN...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC...

LAT...LON 34589498 34459427 33879415 33049469 32459538=20
31539646 32029709 33609655 34289599=20

=3D =3D =3D
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AWUS01 KWNH 080901
FFGMPD
ARZ000-TXZ000-OKZ000-081400-

Mesoscale Precipitation Discussion 0056
NWS Weather Prediction Center College Park MD
400 AM EST Wed Feb 08 2023

Areas affected...Northeast TX...Southeast OK...Southwest AR...

Concerning...Heavy rainfall...Flash flooding possible

Valid 080900Z - 081400Z

SUMMARY...Possible isolated low-end incidents of flash flooding or
increased streamflow as system reloads with approach of main
height-falls toward late morning. Stripes of 2-3" additional
totals may occur with increasingly favorable training with
upstream redevelopment probable.

DISCUSSION...Current RADAR mosaic depicts precipitation shield
with embedded weak showery/convective elements embedded within
across SE OK into SW AR while more widely scattered weak cells
continue to develop upstream near Dallas-Fort Worth. Surface low
continues very slow northeast progress near JDD with increasing
symmetric wind flow, warm sector over the southeast continues to
be weakly unstable with low to mid-60s Tds with slightly warmer
temps, while cold front extends nearly due south toward CFD/11R
before bending west across to another weak weave near PEZ. Above
the boundary layer, broad LLJ continues to provide solid moisture
flux across eastern TX toward the surface low, however, western
edge remains farther west of the shallow cold front and so deeper
layer convergence and isentropic ascent remains limited until in
nearer proximity of the surface low, leading to the increased
shallow convective cores scattered about the DFW metro. RAP
analysis suggest MUCAPE is filtering north of the boundary toward
the Red River Valley to support some increased vertical
development (and therefore increased rainfall efficiency) at least
for a few more hours before best upper level divergence slides a
bit too far away across N AR (3-5hrs, per HRRR/RAP forecasts).=20

Upstream shortwave energy remains weak positive tilt but is
expected to swing eastward increasing convergence along the
western edge of the 850 LLJ. Some thunderstorms are starting to
break through across the southern Permian Basin into the Hill
country of central TX and this shift east should aid upstream
redevelopment across northeast Texas toward 13-15z. This may
allow for short burst convection to track through areas that have
seen recent rainfall overnight and have lowered FFG values across
the region; 1hr values less than 1.5" and 3hr values below 2.5".=20
While, there remain mixed signals to even reaching this potential
within the guidance suite, the current SW-NE orientation of new
activity is parallel to deep layer steering between the exiting
right entrance/shortwave feature in AR and the approaching main
shortwave. This may allow for narrow stripes of enhanced rainfall
with a remaining possibility to exceed the longer term FFG values
suggesting an isolated incident of flash flooding or two may occur
over the next few hours and given modest instability (750-1000
J/kg MUCAPE) rates up to 1" and totals up to 2-3" are possible.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_4CnfSC3_lzlY6crwx8OTSRNmKjnjMAh0FLj2Xg5bVGR0kmJBZaGtQKs_tFLyKuUk9M4= Rwl5Mw0QIR6_kDxvaoWIOZY$ for graphic product...

ATTN...WFO...FWD...LZK...OUN...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC...

LAT...LON 35489391 35209291 34689283 34309301 33769355=20
33329434 32989539 31859672 32479770 33519694=20
34459553 34989496=20

=3D =3D =3D
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AWUS01 KWNH 081528
FFGMPD
LAZ000-MOZ000-ARZ000-TXZ000-OKZ000-082100-

Mesoscale Precipitation Discussion 0057
NWS Weather Prediction Center College Park MD
1027 AM EST Wed Feb 08 2023

Areas affected...Northeast TX...Southeast OK...Central AR

Concerning...Heavy rainfall...Flash flooding possible

Valid 081526Z - 082100Z

SUMMARY...Additional rounds of heavy rain and occasional
thunderstorms are expected going into the early to middle
afternoon hours. There is the potential for some instances of
mainly minor flooding where rainfall rates exceed one inch per
hour and/or several hours of 0.5 to 1 inch/hour rates through 3 pm
local time.

DISCUSSION...Regional Doppler radars are indicating a consistent
swath of moderate to heavy stratiform rainfall with embedded
convective elements across much of central and western Arkansas,
and more in the way of convective rainfall across the ArkLaTex
region where mixed layer CAPE is on the order of 250-750 J/kg
based on recent SPC mesoanalysis. Farther north, there is weak
elevated instability across south-central Arkansas, but otherwise
the lack of appreciable instability is a mitigating factor. This
region also has the greatest PWs which are generally in the 1.4 to
1.7 inch range as of 15Z.

A comparison of the CAM guidance to ongoing radar trends suggest
the latest HRRR runs have a relatively good depiction of what is
currently happening, and the ARW and ARW2 are also in decent
agreement in terms of placement. These models are suggesting the
potential for a corridor of additonal 1.5 to 2.5 inch totals
through 21Z, mainly from Texarkana to Jonesboro, Arkansas.=20
Portions of west-central Arkansas have already registered 2 to 4
inches of rain since midnight local time based on local reports,
and 1.5 to 3 inch reports over portions of southeast Oklahoma.=20
These areas will be a bit more vulnerable to additional rainfall
today, even though extreme rainfall rates are not expected owing
to a lack of sufficient instability. Overall, this is a marginal
case for flash flooding, but enhanced run-off and ponding of water
in poor drainage areas could become a problem for some areas.

Hamrick

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9Y0hDg92-BVNYvxm5vEKWsQouV2CHiRHpxcFbpYRsSJKqeWepJfu0n_jGrmhgbrnQrbT= xFN2ALaNnJnluA2XXdriVgA$ for graphic product...

ATTN...WFO...FWD...LZK...MEG...PAH...SGF...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC...

LAT...LON 36659080 36339017 35329086 34499185 33449326=20
32439457 32489539 32969584 33629564 34769493=20
35519400 36139299 36619217=20

=3D =3D =3D
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AWUS01 KWNH 082137
FFGMPD
MSZ000-LAZ000-090300-

Mesoscale Precipitation Discussion 0058
NWS Weather Prediction Center College Park MD
435 PM EST Wed Feb 08 2023

Areas affected...South-central LA...Southwestern MS

Concerning...Heavy rainfall...Flash flooding possible

Valid 082135Z - 090300Z

SUMMARY...Heavy showers and thunderstorms are increasing in
coverage late this afternoon in the warm sector of a strong low
pressure system. This convection is expected to persist going
into the early-mid evening hours, and some instances of flooding
are possible with the most persistent cells.

DISCUSSION...Regional Doppler radars are indicating a steady
increase in the coverage of strong convection across much of
southern Louisiana and into southwestern Mississippi. Some of the
cells are beginning to exhibit some signs of short-term training,
and this may result in periods of enhanced rainfall rates of 2
inches per hour.=20

The low level jet is getting stronger with southerly 850 mb flow
on the order of 35-45 knots (40-50 mph) advecting copious Gulf
moisture northward in the warm sector ahead of a potent cold
front. In addition, a mid-level vortmax in association with a
amplified shortwave is approaching from Texas, and a coupled upper
level jet structure that will further aid ascent. Instabilty is
also building with mixed layer CAPE on the order of 1000-1500 J/kg
per recent SPC mesoanalysis.

Recent CAM guidance is depicting narrow but heavy rainfall swaths
of 2 to locally 4 inches through 9 pm local time. Ongoing radar
trends appear to be heavier than CAM simulated radar reflectivity,
but the HRRR still serves as a decent proxy. The ARW2 is more
underdone with ongoing rainfall than the other CAM guidance. Some
instances of flooding will be possible.

Hamrick

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!89rUBlzrnnk2qGe0pdsrNPtsT5MOZiVCQ932cRtcljqfwwauLsBG_7WKpAp3AYo9Ufe1= 85qBK4yH9Pd-CcvqaeNApyI$ for graphic product...

ATTN...WFO...JAN...LCH...LIX...SHV...

ATTN...RFC...LMRFC...WGRFC...NWC...

LAT...LON 32779048 32568959 31578942 30948988 30219069=20
29919125 29779185 29689262 29829327 30229359=20
31209326 32269225 32639135=20

=3D =3D =3D
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AWUS01 KWNH 090036
FFGMPD
KYZ000-ILZ000-MOZ000-ARZ000-090604-

Mesoscale Precipitation Discussion 0059
NWS Weather Prediction Center College Park MD
734 PM EST Wed Feb 08 2023

Areas affected...AR and southeast MO

Concerning...Heavy rainfall...Flash flooding possible

Valid 090034Z - 090604Z

SUMMARY...An uptick in rainfall intensity over areas with
saturated or saturating soil conditions may lead to some
additional flash flood concerns over the next several hours from
north central AR into southeast MO.

DISCUSSION...The mid level trough over OK and TX is beginning to
take on more of a negative tilt as it pushes eastward this
evening. This is resulting in an increase in the mid level forcing
and an uptick in low level moisture transport across the lower MS
Valley. The most robust convection is developing south of the warm
front across portions of southern AR, LA and MS. The good news is
that this is south of the areas hardest hit with heavy rainfall
over the past 24 hours.

The harder hit areas, and thus locations with saturated soil
conditions, across central and northern AR are north of the front
and thus displaced from the better instability. With that said,
the increase in forcing should be enough to result in some uptick
in convective coverage/intensity across central and northeast AR
over the next couple hours. Recent HRRR runs support hourly
rainfall up to 1" or so from portions of central AR into far
southeast MO and southern IL...with total additional rainfall of
1-2" in spots.

The MPD area was drawn where there is overlap of more saturated
ground conditions, from the rain that has already fallen, and the
potential for this additional 1-2" of rain. The better chance of
getting closer to 2" is across southeast MO into southern IL,
areas that have not seen as much rain as central AR. Thus there is
some displacement between the most sensitive areas and where the
heaviest additional rainfall is expected. For that reason, and due
to the progressive nature of this final convective line, we will
go with a possible tag for this MPD instead of likely. Current
thoughts are that additional flash flooding should be mainly
localized in nature, although more broader areal flood concerns
will likely continue.

Chenard

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8Hod_Rt3PDh503SwjdW29ta7sflf4CfYNLaMjvQSU7GDOq6A8TbNegx2TEU1I83bMOD3= L1YIq5akyRRHs1Uj3mErQGk$ for graphic product...

ATTN...WFO...LSX...LZK...MEG...PAH...SGF...

ATTN...RFC...ABRFC...LMRFC...NCRFC...NWC...

LAT...LON 37888933 37698912 37258900 36198988 35989003=20
35779024 35289119 34959194 34499270 34699297=20
35399283 35499282 36189253 36829156 37099091=20
37539029 37609022 37848972=20

=3D =3D =3D
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AWUS01 KWNH 090315
FFGMPD
TNZ000-ALZ000-MSZ000-LAZ000-ARZ000-090900-

Mesoscale Precipitation Discussion 0060
NWS Weather Prediction Center College Park MD
1014 PM EST Wed Feb 08 2023

Areas affected...central Gulf Coast into MS, western AL and
southwestern TN

Concerning...Heavy rainfall...Flash flooding possible

Valid 090313Z - 090900Z

SUMMARY...Periods of training will continue a flash flood risk for
portions of LA/MS/AL/TN through 09Z. Rainfall rates of 1-3 in/hr
will be possible but the potential for higher rates will exist
across southern locations where instability will be greater.

DISCUSSION...Regional radar imagery at 0245Z showed widespread
showers and thunderstorms stretching from the central coast of LA
into MS and southwestern TN, located out ahead of an approaching
cold front from the west. MRMS-derived rainfall rates have
generally been peaking in the 1-2 in/hr range over the past few
hours, with 1+ in/hr located as far north as northern MS. MLCAPE
within the ongoing precipitation axis was 500 to just over 1000
J/kg with precipitable water values of 1.5 to 1.8 inches (02Z SPC mesoanalysis). Unidirectional flow from the SSW combined with
strengthening 850 mb winds (35-50 kt at 02Z) was promoting
training segments within the pre-frontal axes of convection.
Supporting enhanced lift was divergent flow aloft within the
entrance region of a 100-120 kt jet streak aloft, located ahead of
a negatively titled upper trough axis swinging through eastern OK
into AR. Wind vectors were also fairly diffluent aloft, as noted
on water vapor imagery, with the greatest fanning out of the upper
flow located near the Gulf Coast.

Expectations are for a continued threat for training as the cold
front steadily moves eastward over the next 3-6 hours. Some
strengthening of the 850 mb flow is anticipated from northern
MS/AL into TN, tied to the greatest CVA out ahead of the mid-upper
level vorticity max. Flash flood guidance is lower for the
northern half of MS/AL into southwestern TN at 2-3 inches in 3
hours but forecasts of lowering instability for these northern
locations should preclude a greater threat for higher rainfall
rates. Across southern locations, south of the I-20 corridor,
instability of 500-1000 J/kg is expected to remain through the
night with the greatest threat for rainfall rates in excess of 2
in/hr focusing within 50 miles of the I-10 corridor.

Additional rainfall totals through 09Z could peak in the 3-5 inch
range for southern locations and 1-3 inches for northern
locations. Flash flooding will be possible for the entire MPD
threat area through 09Z.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4HGF7bIH0g7u3AasWslsxd8XfjJN1VDa3hSK3CvxnJxrHTPOSLAQpRZb0a1iobg-8aVU= vtdSQuDApdL1aLOWBbNprfk$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...LCH...LIX...MEG...MOB...OHX...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 35948879 35748755 35008748 34348767 33628770=20
33218751 32778720 32208710 31588732 30048837=20
29088906 28698991 28899120 29479179 31429132=20
33689079 35348998=20

=3D =3D =3D
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AWUS01 KWNH 101556
FFGMPD
SCZ000-FLZ000-GAZ000-102150-

Mesoscale Precipitation Discussion 0061
NWS Weather Prediction Center College Park MD
1052 AM EST Fri Feb 10 2023

Areas affected...Florida Panhandle, southern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 101550Z - 102150Z

Summary...A few areas of flash flooding will be possible this
afternoon especially along a stalled frontal boundary in southern
Georgia and the Florida Panhandle. Additional, localized areas of
2-3 inch rainfall totals are possible.

Discussion...A band of convection currently resides along a
stalled surface boundary extending from near TLH to near JES.=20
South of that boundary, a warm, moist airmass (characterized by
1000-2000 SBCAPE and 1.6 inch PW values) continued to support deep
updrafts and heavy rainfall. The orientation of the storms was
generally parallel to both 1) flow aloft and 2) the initiating
boundary, allowing for training of storms and localized areas of
1-2.5 inch/hr rainfall rates generally along the surface boundary.
Additional, elevated convection near far southeastern Louisiana
was also migrating toward the discussion area, although at a more
progressive pace compared to convection in the discussion area.

Indications are that the ongoing axis of heavy rainfall will
persist potentially for several hours, with slow eastward
translation off its current axis as governed by upscale growth of
convection into clusters or bows that propagate. The slow
movement of the cells and moist airmass will promote an additional
2-3 inches of rainfall on a localized basis where training is most
pronounced. Upstream convection across southeastern Louisiana
should also add another 0.5-1.5 inch of rainfall on a more
widespread basis despite the more progressive nature of that
convection. FFGs across the region are in the 2.5-3 inch/hr
range, suggesting that any flash flood risk should remain tied to
where training is most pronounced and rain rates are heaviest.=20
Areas of heavier rainfall are likely to persist through 22Z.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4faBTF-BU_M0X4pHW6W6K8YGmkwxXr5xlGu6YZwbeuEki3A3A1CsRXX4ViRkg1roRGIz= 0v4r6-6GShg9OL2p9TNBdJc$ for graphic product...

ATTN...WFO...CHS...FFC...JAX...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 32838142 32028113 30868149 29848252 28908460=20
28798597 30398456 31358358=20

=3D =3D =3D
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AWUS01 KWNH 101602
FFGMPD
SCZ000-FLZ000-GAZ000-102150-

Mesoscale Precipitation Discussion 0061
NWS Weather Prediction Center College Park MD
1102 AM EST Fri Feb 10 2023

Areas affected...Florida Panhandle, southern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 101550Z - 102150Z

Summary...A few areas of flash flooding will be possible this
afternoon especially along a stalled frontal boundary in southern
Georgia and the Florida Panhandle. Additional, localized areas of
2-3 inch rainfall totals are possible.

Discussion...A band of convection currently resides along a
stalled surface boundary extending from near TLH to near JES.=20
South of that boundary, a warm, moist airmass (characterized by
1000-2000 SBCAPE and 1.6 inch PW values) continued to support deep
updrafts and heavy rainfall. The orientation of the storms was
generally parallel to both 1) flow aloft and 2) the initiating
boundary, allowing for training of storms and localized areas of
1-2.5 inch/hr rainfall rates generally along the surface boundary.
Additional, elevated convection near far southeastern Louisiana
was also migrating toward the discussion area, although at a more
progressive pace compared to convection in the discussion area.

Indications are that the ongoing axis of heavy rainfall will
persist potentially for several hours, with slow eastward
translation off its current axis as governed by upscale growth of
convection into clusters or bows that propagate. The slow
movement of the cells and moist airmass will promote an additional
2-3 inches of rainfall on a localized basis where training is most
pronounced. Upstream convection across southeastern Louisiana
should also add another 0.5-1.5 inch of rainfall on a more
widespread basis despite the more progressive nature of that
convection. FFGs across the region are in the 2.5-3 inch/hr
range, suggesting that any flash flood risk should remain tied to
where training is most pronounced and rain rates are heaviest.=20
Areas of heavier rainfall are likely to persist through 22Z.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6uTzt4OJyLMMB7BKqykPNLVcp9568L9LJDOtcyWLeG6y-v37bv-3bJp9lr4HiQy-qn1C= Q2y-tmIM68T6cDuALQtNU-M$ for graphic product...

ATTN...WFO...CHS...FFC...JAX...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 32838142 32028113 30868149 29848252 28908460=20
28798597 30398456 31358358=20

=3D =3D =3D
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AWUS01 KWNH 102227
FFGMPD
FLZ000-GAZ000-110300-

Mesoscale Precipitation Discussion 0062
NWS Weather Prediction Center College Park MD
526 PM EST Fri Feb 10 2023

Areas affected...Southern GA...Northeast FL

Concerning...Heavy rainfall...Flash flooding possible

Valid 102225Z - 110300Z

Summary...Heavy rain with embedded thunderstorms are expected to
continue on the warm side of a quasi-stationary front across
southeast Georgia and northeast Florida. An additional 1 to 3
inches of rain through 10 pm local time may lead to some instances
of minor flooding.

Discussion...Regional Doppler radars continue to indicate
widespread moderate to heavy rainfall from Apalachee Bay to
Waycross Georgia, with a steady influx of deep moisture advecting
northward into the outlook area as precipitable water values
approach 1.75 inches. The overall intensity of the convection has
waned some over the past several hours, however, portions of the
region have received anywhere from 2 to 5 inches of rainfall so
far today, and these areas will be vulnerable to additional heavy
rain.=20

The latest CAM guidance suite is indicating the potential for 1 to
2 inches of additional rainfall in relatively narrow swaths, with
some isolated totals up to three inches possible through 10 pm.=20
This is a borderline flooding potential and this would mainly
result in nuisance level flooding and ponding of roadways and poor
drainage areas. This would mainly be confined to those areas that
had heavy rain earlier this afternoon.

Hamrick

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5GA5au34NHm_lkXyIrgMSQot5i7nJJqxExlAcecuQKkblEV8wO3z6o79JeOPWAWC2_O3= gC8u56sfzbYvRAIKPUL-LQo$ for graphic product...

ATTN...WFO...CHS...JAX...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 31728194 31688133 31308133 30928184 30448238=20
29968263 29638312 29588342 29828369 29968397=20
29948420 29758446 29608478 29548508 29698534=20
30328499 30788442 31178374 31458303 31588267=20
31668235=20

=3D =3D =3D
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AWUS01 KWNH 112350
FFGMPD
SCZ000-GAZ000-120548-

Mesoscale Precipitation Discussion 0063
NWS Weather Prediction Center College Park MD
649 PM EST Sat Feb 11 2023

Areas affected...coastal Georgia & South Carolina

Concerning...Heavy rainfall...Flash flooding possible

Valid 112348Z - 120548Z

Summary...Developing showers and thunderstorms are expected to
continue to expand in coverage and intensity over the next several
hours. Hourly rain totals to 2" with local amounts to 4" are
possible.

Discussion...The 2300 UTC observation set indicated that a low
pressure system appeared to be forming just northwest of the
Okeefenokee swamp in far southern GA. Divergence aloft is being
sponsored by a cold low near the central Gulf coast. Recent
indications via radar and satellite imagery showed increasing
concentration of convective activity near the forming low, with
some local hourly rain estimates up to 1". Other convection
offshore SC closer to the coastal front has been edging closer to
shore over the past couple hours. MU CAPE of 500-1000 J/kg exists
near the low per SPC mesoanalyses. Precipitable water values have
risen above 1.75" per recent GPS data. Effective bulk shear is
30-40 kts across coastal GA. Flow is nearly unidirectional out of
the southwest.

RAP guidance indicates that the low forming in southeast GA is
expected to track northeast towards the central coast of SC over
the next several hours, which would act to bring the coastal front
closer to the coast, if not ashore, which would increase
instability near and ahead of the cyclone. RAP guidance indicates
MU CAPE reaching 1000+ J/kg ahead of the low, which would allow
convection to be more robust, and potentially organize and train.=20
Low to mid-level frontogenesis is expected to overlap with the
incoming instability from roughly Savannah northeastward, which
would aid rainfall efficiency. There is a mild signal in the 18z
HREF of a couple rounds of heavy rainfall, particularly near the
lower and middle SC coast. While the guidance shows greater than
average spread, the expected evolution favors heavy rainfall.=20
Hourly rain totals to 2" with local amounts to 4" are seen on a
couple pieces of mesoscale guidance, and befit the environment
expected to evolve this evening into tonight. Some of this region
has seen rainfall of 100-200% of average over the past week, but
the region is also marshy/swampy. Heavy rain issues should be
more significant/evident in urban areas. Considering the model
dispersion, confidence is lower than average.

Roth

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!498AThTBTnvjevzpUlh069BYRG5cKa9oFpmI85P8xbd5jIcwRIjdOdV9A3enaEvZa8EJ= BmgVc-BqitcyMOYV8oF-3VM$ for graphic product...

ATTN...WFO...CHS...ILM...JAX...

ATTN...RFC...SERFC...NWC...

LAT...LON 33367975 33207909 31958082 30998144 31108246=20
32678141=20

=3D =3D =3D
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AWUS01 KWNH 162116
FFGMPD
VAZ000-WVZ000-OHZ000-GAZ000-TNZ000-KYZ000-ALZ000-MSZ000-170315-

Mesoscale Precipitation Discussion 0069
NWS Weather Prediction Center College Park MD
415 PM EST Thu Feb 16 2023

Areas affected...Portions of the OH Valley and Mid-South

Concerning...Heavy rainfall...Flash flooding possible

Valid 162115Z - 170315Z

SUMMARY...Areas of heavy showers and thunderstorms will continue
to traverse portions of the OH Valley and the Mid-South for the
remainder of the afternoon and through the evening hours.
Additional areas of flash flooding will remain possible from
localized areas of cell-training and locally wet antecedent
conditions.

DISCUSSION...The latest surface analysis shows a cold front
advancing east from portions of the lower OH Valley down through
the lower MS Valley. This is ahead of a deep layer trough over the
Midwest, and low pressure gradually crossing the OH Valley over
the next several hours will drive the cold front east through
through the Mid-South bringing additional rounds of heavy showers
and thunderstorms.

A combination of multicell and supercell convection is expected
over especially the Mid-South going into the evening hours given a
combination of a moderately buoyant boundary layer and strong
vertical shear profiles. The latest RAP analysis shows a nose of
MUCAPE values reaching 500 to 1000 J/kg across middle TN, with
values of 1000 to 1500+ J/kg farther south over northeast MS and
northern AL. Farther north up into areas of eastern KY and
southwest WV, the instability is much weaker given clouds and
ongoing areas of heavy rain, but there is a very modest level of
elevated instability here as well. Strong warm air advection
continues over the region with presence of a 40 to 50 kt southwest
low-level jet ahead of the front, and this will maintain a
favorable thermodynamic environment through the balance of the
afternoon and into the early evening time frame across the
Mid-South for convection.

The PWs across the area continue to gradually rise with given the
Gulf of Mexico source region, with values generally 1.25 to 1.5
inches per GPS-derived data. This coupled with the available CAPE
values over the next few hours should favor some heavy rainfall
rates. Some of the more organized convective structures may be
capable of producing as much as 1.5 to 2 inches per hour.

Hires CAMS do support the idea of there potentially being some
occasional instances of cell-training, and this coupled with the
heavier rates may result in some localized swaths of excessive
totals with some potential for as much as 2 to 4 inches by early
this evening.

This may result in some instances of flash flooding, and
especially over any areas that were impacted earlier with heavy
rainfall given increasingly wet antecedent conditions. The more
urbanized locations will tend to see the greatest threat for
runoff concerns.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!55Gb6FY5TeZcgbB7xmzxM2s2QWMdCZAbu7lOYFSb3IcRqKL0XLzLYFuBX9n3qxtDmZoB= -qFgiyHMsZTTYPQIFjkuuL0$ for graphic product...

ATTN...WFO...BMX...FFC...HUN...JAN...JKL...LMK...MEG...MRX...
OHX...RLX...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 38718161 38438116 37898130 36858298 34918479=20
33778659 33348802 33218903 33628932 34788843=20
36058703 37628461 38468286=20

=3D =3D =3D
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AWUS01 KWNH 162325
FFGMPD
ALZ000-MSZ000-LAZ000-170524-

Mesoscale Precipitation Discussion 0070
NWS Weather Prediction Center College Park MD
624 PM EST Thu Feb 16 2023

Areas affected...portions of MS & AL

Concerning...Heavy rainfall...Flash flooding possible

Valid 162324Z - 170524Z

Summary...Thunderstorms with heavy rainfall should become more
progressive and less efficient from a rainfall perspective later
tonight. Until then, hourly rain totals to 2" with local amounts
to 4" are possible where soils are becoming increasingly saturated.

Discussion...A broad area of thunderstorms continues to develop
and progress ahead of a cold front and attendant upper level
trough. Precipitable water values are 1.5-1.8" per GPS data. MU
CAPE of 1000-2000 J/kg exists near and inland of the central Gulf
Coast. Effective bulk shear is ~60 kts, which along with
unidirectional southwest flow is allowing for the formation of
short, linear bands of thunderstorms. Activity immediately near
the Gulf Coast itself appears to be hindered by 700 hPa
temperatures near or above 6C, which is leading to less rainfall
efficiency.

As instability slowly gets eroded by the incoming cold front and
pre-frontal convection, a narrowing line of thunderstorms is
expected, particularly during the later portion of the MPD period
(at or after 03z), due to squall line formation. Until that
happens, hourly rain totals to 2" with local amounts to 4" are
expected in and around eastern MS and central AL over an area with
increasingly saturated soils/lowering flash flood guidance values.


Roth

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9PBKCoJ_aHJUdtWOdmnrZmGuIZ9yJVJMLUjBa_xrPIwxJw3oxOjQR_79x7YBKN2let93= 9QgEImiaF1SfVQEyMP8almc$ for graphic product...

ATTN...WFO...BMX...JAN...LCH...LIX...MOB...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 34138596 32878546 31098790 30299084 30479195=20
33098888=20

=3D =3D =3D
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