Graphic for MPD #0348

MESOSCALE PRECIPITATION DISCUSSION 0348
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
751 AM EDT FRI JUN 22 2018

AREAS AFFECTED......SOUTHERN ARKANSAS...NORTHERN LOUISIANA...FAR
NORTHEAST TEXAS...

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

VALID 221150Z - 221750Z

SUMMARY...SHOWERS AND THUNDERSTORMS WILL EXPAND AND BACKBUILD THIS
MORNING AHEAD OF A QUASI-STATIONARY SURFACE FRONT. HOURLY RAINFALL
RATES PEAKING BETWEEN 2-3 INCHES MAY RESULT IN FLASH FLOODING.

DISCUSSION...THE LATEST GOES-16 LONGWAVE IR IMAGERY SHOWS A
COMPACT AREA OF COOLING CLOUD TOPS ACROSS SOUTHERN ARKANSAS, ALONG
AND JUST SOUTH OF A STATIONARY FRONTAL BOUNDARY AND ON THE
SOUTHERN PERIPHERY OF THE MID-UPPER LEVEL LOW. THE UPPER LEVEL
CONFLUENCE SOUTH OF THIS UPPER LOW IS INDUCING A RIBBON OF
STRONGER UPPER LEVEL FLOW THROUGH CENTRAL ARKANSAS -- 70 TO 90+
KTS AT 250 MB PER THE LATEST VAD WIND PROFILES AND RAP/HRRR
ANALYSIS. THE ENHANCED UPPER LEVEL DIVERGENCE WITHIN THE RIGHT
ENTRANCE REGION OF THIS JET STREAK, AND ENSUING UPTICK IN THE
LOW-LEVEL MOISTURE FLUX CONVERGENCE ALONG THE FRONT, WILL FURTHER
THE CONVECTIVE GROWTH/ORGANIZATION, ESPECIALLY THROUGH 1500 UTC.

THE THERMODYNAMIC ENVIRONMENT WITHIN THE OUTLOOK AREA IS QUITE
FAVORABLE FOR HEAVY AND POTENTIALLY EXCESSIVE RAINFALL,
PARTICULARLY FOR THE TIME OF DAY, WITH MUCAPES BETWEEN 2000-3000
J/KG AND PWATS OF 1.75-2.0" PER THE LATEST SPC MESOANALYSIS. IN
ADDITION, AS THE WEST-SOUTHWEST 925-850 MB FLOW ALONG AND SOUTH OF
THE SURFACE BOUNDARY INCREASES TO 25-30 KTS, THE RESULTANT UPWIND
PROPAGATION WILL ALLOW THE CONVECTION TO BACKBUILD AND TRAIN.
HOURLY RAINFALL RATES OF 2-3" ARE LIKELY WITHIN THE STRONGEST
CORES, WITH EVENT TOTALS OF 4-7 INCHES POSSIBLE IN A FEW AREAS PER
THE LATEST HIGH-RES CAM GUIDANCE.

HURLEY

ATTN...WFO...JAN...LZK...SHV...

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

LAT...LON   34169385 33889236 33689163 33449128 33069120
            32639141 32289210 32419328 32879413 33639441
            34069426


Last Updated: 751 AM EDT FRI JUN 22 2018