367
AWUS01 KWNH 260401
FFGMPD
LAZ000-ARZ000-OKZ000-261000-
MESOSCALE PRECIPITATION DISCUSSION 0134
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1200 AM EDT SUN APR 26 2026
AREAS AFFECTED...FAR EASTERN OKLAHOMA...WESTERN AND SOUTHERN
ARKANSAS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY
VALID 260400Z - 261000Z
SUMMARY... ELEVATED THUNDERSTORMS WILL CONTINUE TO ORGANIZE AND
DROP SOUTHEASTWARD ACROSS WESTERN AND SOUTHERN ARKANSAS OVERNIGHT.
LOCALLY SENSITIVE ANTECEDENT CONDITIONS COMBINED WITH RATES
APPROACHING 2 INCHES/HOUR WILL SUPPORT A LIKELIHOOD FOR ISOLATED
TO SCATTERED AREAS OF FLASH FLOODING WHICH WILL INCLUDE SOME URBAN
IMPACTS.
DISCUSSION...A BROKEN AXIS OF SLOW-MOVING AND LOCALLY TRAINING
THUNDERSTORMS IS ONGOING ACROSS FAR EASTERN OKLAHOMA AND WESTERN
ARKANSAS. UNLIKE THE SURFACE-BASED ACTIVITY FURTHER SOUTHWEST,
THIS CONVECTION IS ELEVATED AND ROOTED NEAR THE 850 MB LAYER. IT
IS BEING DRIVEN BY STRONG 850 MB FRONTOGENETIC LIFT AND THE
PROXIMITY OF A SHARP INSTABILITY GRADIENT, WITH THE CONVECTION
POSITIONED WELL WITHIN AN AXIS OF 1500-2500 J/KG MUCAPE AND PWS
NEAR 1.25 INCHES.
UPWIND PROPAGATION VECTORS POINT TOWARD THE SOUTHEAST. OVER THE
NEXT SEVERAL HOURS, THIS ACTIVITY IS EXPECTED TO GRADUALLY GROW
UPSCALE, BUT WITH MULTIPLE MCS CLUSTERS DROPPING SOUTHEASTWARD AS
THROUGH WEST-CENTRAL AND EVENTUALLY SOUTHERN ARKANSAS. THE 00Z
HREF HIGHLIGHTS A 20 TO 30 PERCENT PROBABILITY OF 2 INCH/HOUR
RAINFALL RATES WITHIN THE HEAVIEST CONVECTIVE ELEMENTS. TOTAL
RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE ANTICIPATED WHERE SOME OF
THESE CONVECTIVE CLUSTERS REPEAT OVER THE SAME AREA.
THE PRIMARY DRIVER FOR THE FLASH FLOOD THREAT IN THIS CORRIDOR IS
THE RELATIVELY SENSITIVE ANTECEDENT CONDITIONS FROM RECENT
RAINFALL. THE LATEST NASA SPORT 0 TO 10 CM RELATIVE SOIL MOISTURE
DATA INDICATES HIGHLY MOIST ANTECEDENT CONDITIONS ACROSS EASTERN
OK AND WESTERN AR. WITH A FAIRLY COMPROMISED INFILTRATION
CAPACITY, THE ANTICIPATED 2 INCH/HOUR RATES AND ANY LOCALIZED
CELL-TRAINING WILL READILY CONVERT TO RUNOFF, POSING A CONTINUED
FLASH FLOOD THREAT THROUGH THE PREDAWN HOURS.
ORRISON
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...JAN...LZK...SHV...TSA...
ATTN...RFC...ORN...TUA...NWC...
LAT...LON 36149347 35579257 34639166 33889125 33219159
32989235 33199342 34399461 35469508 36069459
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