MESOSCALE PRECIPITATION DISCUSSION 0053
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1128 PM EDT SUN MAY 19 2013
 
AREAS AFFECTED...NORTHEAST OK...SOUTHEAST KS...WESTERN AND
NORTHERN MO 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 200328Z - 200925Z
 
SUMMARY...A SLOW-MOVING BAND OF CONVECTION FROM NORTHEAST OK
THROUGH SOUTHEAST KS AND WESTERN MO IS EXPECTED TO MOVE VERY
LITTLE OVERNIGHT, WHICH COULD LEAD TO FLASH FLOODING.

DISCUSSION...AN OUTFLOW BOUNDARY JUST AHEAD OF THE SYNOPTIC-SCALE
COLD FRONT IS CURRENTLY FOCUSING A BAND OF THUNDERSTORMS FROM
NORTHEAST OK ACROSS SOUTHEAST KS INTO WESTERN MO.  A COMBINATION
00Z SOUNDING DATA AND MESOSCALE MODEL GUIDANCE INDICATE THAT THE
BEST 850 HPA INFLOW -- ON THE ORDER OF 40-60 KNOTS -- INTO THE
REGION IS HELPING TO BACKBUILD/TIE THE SOUTHWEST END OF CONVECTION
TO NORTHEAST OK. PRECIPITABLE WATER VALUES -- PWS -- OF 1.50-1.75
INCHES ARE AVAILABLE TO THE CONVECTION.  THE SURFACE-BASED CAPE IN
THE 12Z ARW INDICATES LITTLE MOVEMENT TO THE OVERALL INSTABILITY
ACROSS THE REGION OVERNIGHT.  PROPAGATION/CORFIDI VECTORS SUGGEST
CELL TRAINING, BECOMING MORE ALIGNED ALONG A WSW-ENE AXIS.  THE
GUIDANCE INDICATES THAT THE 850 INFLOW AXIS COULD BACK UP SOMEWHAT
OVERNIGHT, WHICH COULD LEAD TO SOME PORTION OF THIS RAINFALL BAND
STALLING OUT -- OR POSSIBLY REDEVELOPING SLIGHTLY FARTHER WEST --
IN THE RELATIVELY NEAR FUTURE PARTICULARLY NEAR ITS TAIL END
ACROSS OK.  WHILE FLASH FLOOD GUIDANCE VALUES -- FFGS -- ARE ON
THE ORDER OF 3 INCHES/3 HOURS, THE OKLAHOMA MESONET HAS INDICATED
THAT AROUND 2 INCHES OF RAINFALL HAS ALREADY FALLEN IN ASSOCIATION
WITH THIS BAND, WHICH SHOULD HAVE LOWERED FFGS FROM THEIR 00Z
VALUES.  THE LATEST NSSL PRECIPITATION ESTIMATES FOR THE REGION --
MUCH LIKE OTHER RADAR ESTIMATES FOR THE REGION -- APPEAR TOO HIGH
DUE TO HAIL CONTAMINATION.  ALOFT, THERE IS SIGNIFICANT
DIRECTIONAL AND SPEED DIVERGENCE ACROSS THE REGION WHICH SHOULD
PERSIST DUE TO THE RELATIVELY STAGNANT UPPER-LEVEL PATTERN.  THE
MESONET GUIDANCE INDICATES THIS PRECIPITATION SHOULD REMAIN
PRACTICALLY IN PLACE THROUGH 12Z/7 AM CDT, SO USED A SIX HOUR TIME
FRAME FOR VALID TIME.  LOCAL RAINFALL AMOUNTS OF 3-6 INCHES ARE
POSSIBLE IN ASSOCIATION WITH THIS BAND.  CONFIDENCE IS MODERATE IN
FLASH FLOODING, WHICH LED TO THE POSSIBLE WORDING.

ROTH


ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN...

LAT...LON   36079819 37899613 40439359 40449249 39179255 37179411
            35969627 36079819