Graphic for MPD #0030

MESOSCALE PRECIPITATION DISCUSSION 0030
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
438 PM EST THU FEB 22 2018

AREAS AFFECTED...FAR NORTHEAST TX...FAR SOUTHEAST OK...SOUTHWEST
TO NORTHEAST AR

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

VALID 222135Z - 230330Z

SUMMARY...ADDITIONAL HEAVY RAINFALL WITH CONCERNS FOR RUNOFF
AND/OR FLASH FLOODING WILL CONTINUE WELL THROUGH THE EVENING HOURS.

DISCUSSION...THE LATEST GOES-16 IR SATELLITE IMAGERY SHOWS
NUMEROUS CLUSTERS OF COLD-TOPPED CONVECTION WHICH IS ELEVATED IN
NATURE UP ACROSS A LARGE AREA OF CENTRAL AND WESTERN AR AND
EXTENDING DOWN ACROSS FAR SOUTHEAST OK AND TO A LESSER EXTENT FAR
NORTHEAST TX. THE CONVECTION CONTINUES TO BE FOCUSING ALONG THE
LEADING EDGE OF A SURGE OF STRONGER WARM AIR ADVECTION AHEAD OF A
SHORTWAVE TROUGH LIFTING NORTHEAST ACROSS THE CENTRAL AND SOUTHERN
PLAINS.

STRONGER MOISTURE AND INSTABILITY TRANSPORT...WITH AN AXIS OF 1.3
TO 1.5 INCH PWATS AND MUCAPE VALUES OF 500 TO 1000 J/KG CONTINUES
TO LIFT NORTHEAST AHEAD OF THE SHORTWAVE WITH THE HELP OF A
SOUTHWEST LOW LEVEL JET OF 40 TO 45 KTS. ALL OF THIS IS WELL NORTH
OF A STATIONARY FRONT AND WAVE OF LOW PRESSURE SITUATED DOWN
ACROSS SOUTHEAST TX...BUT SUFFICIENT LARGE SCALE FORCING AHEAD OF
THE SHORTWAVE AND THERMODYNAMICS ARE IN PLACE TO MAINTAIN THE
CONVECTIVE THREAT MOVING INTO THE EVENING HOURS.

THE LATEST CAM GUIDANCE LED BY THE 12Z ARW/ARW2 SOLUTIONS AND THE
12Z GEM REGIONAL APPEAR TO HAVE A REASONABLY GOOD HANDLE OF THE
LATEST CONVECTIVE TRENDS AND SUPPORT THE IDEA OF ADDITIONAL
CONVECTION DEVELOPING IN A GENERAL SW/NE ORIENTATION GOING THROUGH
THE MID-EVENING HOURS AS UPPER LEVEL FORCING STRENGTHENS FURTHER
WHILE ALSO INTERACTING WITH A CORRIDOR OF FOCUSED LOW LEVEL
MOISTURE CONVERGENCE AND ELEVATED INSTABILITY. GLOBAL MODELS
INCLUDING THE 12Z ECMWF AND 12Z UKMET ALSO FAVOR THIS SCENARIO.

RAINFALL RATES CONTINUE TO BE RANGING AS HIGH AS 1 TO 1.25
INCHES/HR WITH THE STRONGER CONVECTIVE CORES...AND THESE RATES
SHOULD TEND TO CONTINUE AS ADDITIONAL CONVECTION DEVELOPS AND
ORGANIZES. THE AFOREMENTIONED CAM GUIDANCE SUPPORTS ANOTHER 1.5 TO
2 INCHES GOING THROUGH ABOUT 03Z...WHICH MAY LOCALLY BE UNDERDONE
WHERE STRONGER CONVECTIVE ELEMENTS CAN REPEAT OVER THE SAME AREA.
GIVEN THE SATURATED SOIL CONDITIONS...THESE ADDITIONAL RAINS WILL
ONLY AGGRAVATE RUNOFF CONCERNS AND MAY PRODUCE ADDITIONAL FLASH
FLOODING CONCERNS.

ORRISON

ATTN...WFO...FWD...LZK...MEG...SHV...TSA...

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

LAT...LON   36349108 36139052 35539063 34479166 33389319
            32799441 32979528 33589549 34359481 35219388
            35939290 36319184


Last Updated: 438 PM EST THU FEB 22 2018