MESOSCALE PRECIPITATION DISCUSSION 0233...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
459 PM EDT TUE MAY 24 2016
 
CORRECTED FOR TYPO IN AREAS AFFECTED

AREAS AFFECTED...NORTHERN AND CENTRAL AR...SOUTHEASTERN MO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 242022Z - 250222Z
 
SUMMARY...TRAINING CONVECTION ALONG A OUTFLOW-REINFORCED THERMAL
BOUNDARY ACROSS NORTHERN AR MAY SUPPORT LOCALLY HEAVY RAINFALL
ACCUMULATIONS LEADING TO FLASH FLOODING.

DISCUSSION...RADAR FROM KSGF AND SURFACE OBSERVATIONS SHOW A
WELL-DEFINED OUTFLOW BOUNDARY FROM CONVECTION THAT DEVELOPED OVER
CENTRAL MO PUSHING SOUTH AND EAST ACROSS SOUTHERN MO INTO NORTHERN
AR.  THIS BOUNDARY IS EXPECTED TO CONTINUE TO DROP FURTHER SOUTH
INTO NORTHERN AR...REINFORCING A THERMAL BOUNDARY ALREADY IN PLACE
ACROSS THE REGION.  ALONG THIS BOUNDARY...THE LATEST SPC
MESOANALYSIS SHOWS PWS OF 1.7-1.8 INCHES AND MUCAPE VALUES AROUND
3000 J/KG.  THIS BOUNDARY IS EXPECTED TO BE A FOCUS FOR TRAINING
CONVECTION THROUGH THE REMAINER OF THE LATE AFTERNOON INTO THE
EARLY EVENING HOURS.  THE 18Z RAP SHOWS SUSTAINED 20 KT SOUTHERLY
850MB INFLOW SUPPORTING PWS OF 1.5-1.75 INCHES ALONG WITH MUCAPES
OF 1000-2000 J/KG.  MEANWHILE...THE FLOW IS EXPECTED TO REMAIN
WIDELY DIFFLUENT ALOFT...WITH AN UPSTREAM MID-LEVEL SHORTWAVE
MOVING OUT OF EASTERN OK CONTINUING TO PROVIDE LARGER-SCALE LIFT. 
BY 03Z...CONVECTION IS EXPECTED TO BEGIN TO PROPAGATE FURTHER TO
THE SOUTH AND EAST AS THE MID LEVEL SHORTWAVE MOVES INTO
NORTHEASTERN AR.

UNFORTUNATELY...THE MAJORITY OF THE HI-RES GUIDANCE HAS PERFORMED
POORLY WITH RESPECT TO THE ONGOING CONVECTION OVER CENTRAL AND
SOUTHERN MO.  TWO RELATIVE EXCEPTIONS ARE THE 18Z HRRR AND THE 12Z
WRF-NMM RUN FOR SPC.  GIVEN THIS POOR MODEL PERFORMANCE...FORECAST
CONFIDENCE WITH RESPECT TO RAINFALL AMOUNTS OVER THE NEXT FEW
HOURS IS LIMITED.  HOWEVER...THE HRRR DOES SUPPORT WIDESPREAD
COVERAGE OF 1-2 INCHES...WITH LOCALLY HEAVIER AMOUNTS THROUGH 02Z.

PEREIRA

ATTN...WFO...LZK...MEG...PAH...SGF...TSA...

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

LAT...LON   37009078 36618993 35519051 35069188 34959307 
            35189421 35789427 36029273 36459200