MESOSCALE PRECIPITATION DISCUSSION 0426
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
501 AM EDT FRI AUG 07 2015
AREAS AFFECTED...SOUTHERN MO...NORTHERN AR
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 070855Z - 071300Z
SUMMARY...SOME TRAINING CONVECTION OVER THE NEXT COUPLE OF HOURS
MAY RESULT IN SOME FLASH FLOODING.
DISCUSSION...RAPIDLY COOLING CONVECTIVE TOPS ARE NOTED EARLY THIS
MORNING OVER PORTIONS OF SOUTHWEST MO...WHICH IS EXPECTED TO HAVE
SOME TENDENCY TO BACKBUILD AND TRAIN OVER THE SAME AREA OVER THE
NEXT FEW HOURS. THE CONVECTION IS GENERALLY MOVING NW/SE DOWN THE
EASTERN FLANK OF A RATHER STRONG INSTABILITY GRADIENT...WITH THE
ACTIVITY ALSO TENDING TO FOCUS ALONG A SURFACE MOISTURE
CONVERGENCE AXIS.
THE 07Z HRRR AND 00Z NSSL-WRF BOTH INDICATE AN AXIS OF SUFFICIENT
INSTABILITY/FORCING FOR PERHAPS MULTIPLE NW/SE ORIENTED BANDS OF
CONVECTION WHICH WILL LIKELY TRAIN OVER THE SAME AREA FOR AT LEAST
A BRIEF AMOUNT OF TIME GIVEN THE DEEPER LAYER NORTHWEST FLOW OVER
THE REGION. THIS WILL ALLOW CONVECTION OVER SOUTHERN MO TO TRAVEL
DOWN INTO PORTIONS OF NORTHERN AR OVER THE NEXT 1 TO 2 HOURS.
GOES-SOUNDER PWATS OVER SOUTHWEST MO ARE NEAR 2 INCHES...AND SO
VERY INTENSE RAINFALL RATES WILL BE LIKELY WITH THESE CELLS.
THE HIRES GUIDANCE IN GENERAL MAY BE A TAD UNDERDONE GIVEN THE
DEEP MOISTURE PROFILES. EXPECT THE POTENTIAL FOR LOCALLY 2 TO 4
INCHES OF RAIN THROUGH ABOUT 12Z AND GIVEN 3-HOUR FFG VALUES OF 2
TO 2.5 INCHES...SOME RUNOFF PROBLEMS/FLASH FLOODING WILL BE
POSSIBLE.
ORRISON
ATTN...WFO...LZK...MEG...PAH...SGF...TSA...
ATTN...RFC...ABRFC...LMRFC...MBRFC...
LAT...LON 37579387 37569297 37069163 36409074 35559030
34849056 34779143 36589373 37309409
Last Updated: 501 AM EDT FRI AUG 07 2015