MESOSCALE PRECIPITATION DISCUSSION 0037
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1024 PM EST FRI FEB 23 2018

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

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 240320Z - 240920Z

SUMMARY...ONGOING PRECIPITATION IS EXPECTED TO CONTINUE AND TRAIN
NORTHEAST FROM NORTHEAST OK AND NORTHWEST AR INTO CENTRAL MO. 
LOCALLY HEAVY ACCUMULATIONS ARE POSSIBLE...PRODUCING ADDITIONAL
FLASH FLOODING CONCERNS.

DISCUSSION...A COUPLED UPPER JET STRUCTURE ALONG WITH GOOD
ISENTROPIC LIFT WILL CONTINUE TO SUPPORT TRAINING PRECIPITATION
ACROSS THE REGION INTO THE OVERNIGHT HOURS.  SPC MESOANALYSIS
SHOWS MOISTURE CONTINUING TO DEEPEN ACROSS SOUTHERN MO...WITH PWS
INCREASING TO AT OR ABOVE AN INCH IN THE LATEST ANALYSIS.  RECENT
RUNS OF THE RAP SHOW A FURTHER INCREASE INTO THE OVERNIGHT HOURS
AS SOUTHWESTERLY LOW LEVEL INFLOW INCREASES TO 40-50 KTS WITH THE
APPROACH OF A SHORTWAVE TROUGH LIFTING ACROSS OK.  IN ADDITION TO
THE INCREASE IN MOISTURE...THE RAP ALSO SHOWS INSTABILITY
INCREASING AS WELL...INDICATING INCREASING MUCAPES AS THE NIGHT
PROGRESSES.  RADAR RETURNS FROM TULSA...FT SMITH AND TULSA HAVE
SHOWN RAINFALL RATES OF UP TO 1 IN/HR IN SOME OF THE MORE
CONVECTIVE ELEMENTS. GIVEN THE WET ANTECEDENT CONDITIONS...THESE
RATES HAVE ALREADY BEEN SHOWN TO BE PROBLEMATIC ACROSS PORTIONS OF
THE AREA...WITH FLASH FLOODING REPORTED IN PARTS OF NORTHEAST OK
AND NORTHWEST AR. AS THE NIGHT PROGRESSES...DEEPENING MOISTURE AND
INCREASING INSTABILITY ARE LIKELY TO FURTHER BOLSTER THESE RATES
IN SOME AREAS.  LATEST RUNS OF THE HRRR HAVE BEEN FAIRLY
CONSISTENT IN SHOWING AN AXIS OF MODERATE TO LOCALLY HEAVY AMOUNTS
EXTENDING FROM NORTHEAST OK AND NORTHWEST AR NORTHEASTWARD INTO
SOUTHERN MO...WITH 6-HR AMOUNTS OF 1.5 TO 2 INCHES WITHIN THE
HIGHLIGHTED AREA.  0Z FLASH FLOOD GUIDANCE VALUES ARE AS LOW AS
1.5 INCHES/3 HRS ACROSS PORTIONS OF THE REGION...SUGGESTING THAT
FLASH FLOODING MAY BECOME A FURTHER CONCERN IF THESE HEAVIER
AMOUNTS DO MATERIALIZE.

PEREIRA

ATTN...WFO...LSX...SGF...TSA...

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

LAT...LON   38649112 38049116 37289213 36439370 35719487
            36249523 37259429 38019349 38569226