MESOSCALE PRECIPITATION DISCUSSION 0276
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
814 PM EDT SAT MAY 27 2017

AREAS AFFECTED...NORTHEAST OK...SOUTHERN MO...NORTHERN AR

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 280011Z - 280440Z

SUMMARY...STRONG THUNDERSTORMS EXTENDING FROM NORTHEAST OK ACROSS
SOUTHERN MO WILL LIKELY PRODUCE FLASH FLOODING DURING THE NEXT
SEVERAL HOURS.

DISCUSSION...THUNDERSTORMS DEVELOPING IN NORTHEAST OK AND
EXTENDING EAST ACROSS SOUTHERN MO ARE PRODUCING HOURLY RAIN RATES
OF 1-2"...AND RADAR SHOWS LOCAL ACCUMULATIONS ALREADY EXCEEDING
3". THE STORMS ARE DEVELOPING AND MOVING ALONG A WEAK FRONTAL
BOUNDARY ACROSS THE THREAT AREA.

SURFACE DEW POINTS ALONG AND SOUTH OF THE BOUNDARY ARE GENERALLY
70 DEGREES F OR HIGHER...WITH PRECIPITABLE WATER VALUES IN THE
RANGE 1.5-1.8". SPC MESOANALYSES SHOW THAT MUCAPE RANGES MAINLY
FROM 3500-5000 J/KG...ALTHOUGH MUCAPES ARE LOCALLY NEAR 6000 J/KG
IN NORTHEAST OK WHERE STORMS ARE CONTINUING TO FORM. THE
BACKBUILDING OF THE LINE OF CONVECTION INTO NORTHEAST OK...AND THE
EASTWARD MOVEMENT OF CELLS ALONG THE BOUNDARY MEANS THAT
SIGNIFICANT TRAINING IS POSSIBLE. IT IS ALSO POSSIBLE THAT STORM
DEVELOPMENT WILL SHIFT SLIGHTLY SOUTHWARD INTO NORTHERN AR DURING
THE NEXT FEW HOURS...AS STORMS MOVE INTO THE MOISTER AND MORE
UNSTABLE AIR.

AN ADDITIONAL 2-3" OF RAIN LOOKS LIKELY ACROSS MUCH OF THE
AREA...AND LOCAL TOTALS OF 4" ARE POSSIBLE. THE LAST SEVERAL RUNS
OF THE HRRR SUPPORT THE IDEA OF LOCAL RAINFALL TOTALS OF 4".

ADDITIONAL FLASH FLOODING IS LIKELY.

MCDONNAL

ATTN...WFO...ICT...LSX...LZK...MEG...OUN...PAH...SGF...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...

LAT...LON   38419198 37938990 36468894 35578957 35469422
            35929659 36319668 36769649 37309551