National Weather Service Text Product Display

Flash Flood Guidance
Issued by NWS
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000
AWUS01 KWNH 302251
FFGMPD
LAZ000-ARZ000-TXZ000-OKZ000-310300-

Mesoscale Precipitation Discussion 0119
NWS Weather Prediction Center College Park MD
650 PM EDT Mon Mar 30 2020

Areas affected...Northeast TX...Southeast OK...Southern
AR...Northwest LA

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

Valid 302249Z - 310300Z

SUMMARY...Convection is increasing in coverage across the ArkLaTex
region and is forecast to continue going into the evening hours.
Some localized flooding will be possible with the stronger storms,
with rainfall rates approaching 1.5 inches per hour at times where
storms train over the same locations.

DISCUSSION...Regional Doppler radars indicate widespread heavy
showers and embedded thunderstorms over northeast Texas, and these
will continue tracking towards the northeast across southeast
Oklahoma, northeast Louisiana, and southern Arkansas through 3Z.
Many of these areas have received moderate rain earlier today,
with 3-hr flash flood guidance values as low as 1.5 inches in some
locoations.  This activity is expected to expand some in coverage
as it tracks northeastward into the ArkLaTex region over the next
several hours, and multiple rounds of strong storms are possible.

A potent shortwave disturbance is approaching the region from
western Oklahoma, and combined with a 130+ knot upper level jet,
this is creating an environment for deep layer ascent.  A low
level jet increasing to 40-50 knots based on the latest RAP model
projection will advect 1.5 to 1.75 inch PWs northward into the
region.  In additional, there should be enough MUCAPE available to
fuel these storms, generally on the order of 500 to 750 J/kg based
on the latest SPC mesoanalysis.

The most recent HRRR and HRRRx appear to have the best handle on
the ongoing convection.  These high res models are indicating
local swaths of 2-3 inches of rainfall through 2Z from eastern
Arkansas to southern Indiana.  Flash flooding will be possible in
those areas where storms persist the longest.

Hamrick

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...FWD...JAN...LZK...SHV...TSA...

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

LAT...LON   34719328 34689250 34219166 33739143 33219165
            32849222 32479290 32209347 31959402 31809460
            31799511 31919577 32209611 32529630 33219617
            33799556 34279462 34579399
National Weather Service Weather Forecast Office
