Graphic for MPD #0291
MESOSCALE PRECIPITATION DISCUSSION 0291...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
310 PM EDT FRI JUN 02 2017

CORRECTED FOR EXPANSION OF AREA OF CONERN

AREAS AFFECTED...NORTH CENTRAL TX ...EXT SOUTH CENTRAL OK

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

VALID 021840Z - 022300Z

SUMMARY...INCREASING CONVECTIVE COVERAGE AND INTENSITY WITH SLOW
EASTWARD PROGRESSION MAY CAUSE LOCALIZED FLASH FLOODING CONCERNS
PARTICULAR IN DALLAS-FORT WORTH METROPLEX.

DISCUSSION...RADAR AND SATELLITE MOSAIC DENOTE COLD POOL FROM
EARLY MORNING CONVECTION IN THROCKMORTON COUNTY IS PROGRESSING
INTO AREAS UNAFFECTED BY DENSE CLOUD COVER NEAR THE DFW METRO
WHERE INSTABILITY WAS ABLE TO BUILD UP AS SFC T REACH UPPER 80S
AND TDS INTO THE LOWER 70S SBCAPES TO 2500 J/KG.  AT THE SURFACE
AN OLD FRONTAL BOUNDARY IS LAID OUT W-E FROM DTO TO JXI...WITH
CONVECTION DEVELOPING ALONG IT AS WELL.  IN THE UPPER LEVELS FLOW
IS EXTREMELY WEAK AND ALMOST DRIVEN FULLY BY THE MESOSCALE UPSCALE
GROWTH FROM THE EARLY MORNING MCS AS WELL.  3H FLOW SHOWS
EXCELLENT ANTICYCLONIC BUBBLE WITH STRONGEST OUTFLOW ON THE
WESTERN PERIPHERY. 925-7H FLOW IS GENERALLY WEAK BUT ALSO QUITE
CONVERGENT TOWARD THE INTERFACE OF THE OUTFLOW AND FRONTAL
BOUNDARY...AS SUCH SOME ENHANCED ISENTROPIC ASCENT IN THE
EFFECTIVE TROWAL SHOULD SPARK DEEPER ASCENT/CONVECTION AS WELL
PARTICULARLY CLOSER TO THE TRIPLE POINT WHERE ENVIRONMENTAL
INSTABILITY IS GREATEST.  OVERALL CLOUD BEARING FLOW IS LESS THAN
10KTS WITH 5KT EASTWARD PROPAGATION.  AS SUCH THE ORGANIZATION MAY
BE A BIT MORE SCATTERED THAN TRADITIONALLY EXPECTED WITH AN MCS
BUT SLOW CEL MOTIONS AND PARAMETERS SUPPORTIVE OF RAIN RATES OVER
2"/HR LEAD TO THE POTENTIAL FOR SPOTTY 2.5-3.5" TOTALS OVER THE
NEXT FEW HOURS.  WHILE FFG VALUES ARE HIGH...THE PROXIMITY THE
URBAN CORRIDOR PRESENT THE GREATEST FF RISK.

FURTHER SW ALONG I-20...THE TRAILING EDGE OF THE OUTFLOW BOUNDARY
WHERE IT BECOMES GENERALLY PARALLEL TO THE EASTWARD ADVANCEMENT OF
THE OUTFLOW BOUNDARY...A SECONDARY AREA OF CONCERN FOR FF (PERHAPS
EVEN MORE SIGNIFICANT TOTALS) MAY EVOLVE AS CONVERGENCE IS
MAXIMIZED AND BACK-BUILDING PROPAGATION VECTORS MAY SUPPORT NEAR
ZERO CLUSTER MOTIONS ALLOWING FOR TOTALS.  CONFIDENCE IS A BIT
LOWER HERE FOR THIS CLUSTER TO EVOLVE THOUGH BEARS CLOSE
MONITORING.

GALLINA

ATTN...WFO...FWD...OUN...SJT...

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

LAT...LON   34329712 34169657 33479619 32919619 32379639
            32079684 31879765 31819896 32499924 32759833
            33299774 34029753


Last Updated: 310 PM EDT FRI JUN 02 2017