Mesoscale Precipitation Discussion 0149
NWS Weather Prediction Center College Park MD
1125 AM EDT Sun Apr 20 2025

Areas affected...Eastern OK...Northwest AR...Southwest
MO...Southeast KS...

Concerning...Heavy rainfall...Flash flooding likely

Valid 201525Z - 202115Z

SUMMARY...Recharging thermodynamic enivorment and strong forcing
starting to initiate scattered convective activity capable of
intense rain-rates (1-1.5"/hr) across saturated soils conditions
possible to result in renewed flash flooding conditions locally.

DISCUSSION...GOES-E WV suite depicts about 1.5 standard deviation
deep closed low centered across SW OK continuing to lift
northeastward with a negative tilt orientation extending across
the Red River Valley.  The suite along the RADAR mosaic also
denotes the southern stream shortwave/MCV from last evening's
convective complex remains at the western gradient of the warm
conveyor belt in southwest MO lifting north-northeastward.  The
pair support a stronger 1008/9mb surface low across central OK
with a warm front extending eastward across southeast OK while a
progressive cold front is undercutting through northeast TX.  The
Ozarks/Boston Mountains along with worked over surface environment
breaks the frontal zone across NE OK toward a weakness in the
surface pattern across SW MO associated with the aforementioned
shortwave.

The interaction with these waves and strong dynamics (DPVA and
right entrance ascent pattern) across E OK is strengthening and
backing low level warm sector and sharpening the FGEN fields
across central to northeast OK into SW OK.  VWP suite shows
southerly flow strengthening to 40-50kts through 700mb advecting
the conditionally unstable airmass across E TX/W AR where breaks
in cloud cover are bringing temperatures into teh low 70s with
increasing surface Tds into the mid 60s resulting in SBCAPEs over
1000 J/kg.  Given the advective environment/strong backing flow
and isentropic ascent downstream of the height-falls; moisture
convergence/FGEN is strengthening across E OK attm.  

As such, regional RADAR depicts increasing shallow convective
coverage across Coal/Hughes/Creek county axis with more widely
scattered activity further northeast along the WAA/FGEN axis into
SW MO.  Total PWats of 1.25, steadily increasing toward 1.5" and
vertical development should support rates of 1-1.5"/hr with bulk
falling in less than 30 minutes.  Forward propagation is likely to
initially limit overall totals initially to 1-1.5", but will be
falling across compromised soil conditions likely to exceed the
lowered FFG values (.75-1.5"/hr), the forward speed/coverage of
the rainfall may be limited and only result in re-aggravating
flash flooding conditions across the area; however, as the
afternoon progresses, increased heating/convective vigor will
increase coverage allowing for broader coverage particularly along
a SW to NE axis near the triple point as it lifts across NE OK,
far SE KS, SW MO where training/repeating will occur where SWly
steering flow is more parallel to the FGEN axis.  This is also
where FFGs are further compromised below .5"/hr likely resulting
in broader areas of flash flooding into the mid-afternoon.

Gallina

ATTN...WFO...EAX...ICT...OUN...SGF...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC...

LAT...LON   38819352 38499282 37759260 37279277 36549330
            35549393 34999446 34649485 34139579 34439655
            35459673 36269662 37029605 38269479 38689419