WPC Met Watch |
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Mesoscale Precipitation Discussion: #0019 (2015) |
(Issued at 920 PM EDT WED MAR 25 2015
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MPD Selection |
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MESOSCALE PRECIPITATION DISCUSSION 0019
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
920 PM EDT WED MAR 25 2015
AREAS AFFECTED......CENTRAL TO NORTHEAST OK...NORTHERN
AR...SOUTHERN MO...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY
VALID 260118Z - 260518Z
SUMMARY...FAVORABLE INSTABILITY PROFILE WITH STRONG LOW-LEVEL
MOIST INFLOW INTERACTING WITH A FRONTAL ZONE AHEAD OF AN
AMPLIFYING MID-LEVEL SHORTWAVE SHOULD CONTINUE TO LEAD TO
LOCALIZED HOURLY RAIN RATES OF 2 TO 2.5, WHICH WOULD LEAD TO FLASH
FLOODING IN AREAS WHERE CELLS BACKBUILD AND/OR TRAIN.
DISCUSSION...AN AMPLIFYING UPPER LEVEL SHORTWAVE ALOFT ACROSS THE
SOUTHERN PLAINS IS COUPLING WITH INCREASED FORCING WITHIN THE
RIGHT ENTRANCE REGION OF THE JET STREAK ACROSS THE UPPER MIDWEST
TO PRODUCE A WIDESPREAD AREA OF SHOWERS AND THUNDERSTORMS ACROSS
EASTERN PORTIONS OF THE SOUTHERN PLAINS EAST-NORTHEAST INTO THE
MID MISSISSIPPI VALLEY. HEAVIER RAINFALL RATES WERE BEING OBSERVED
ALONG AND SOUTH OF THE SURFACE STATIONARY BOUNDARY...FROM CENTRAL
AND NORTHEAST OKLAHOMA INTO NORTHERN ARKANSAS AND SOUTHERN
MISSOURI. THIS IS WHERE THE BEST DEEP LAYER INSTABILITY
EXISTS...AS THE CONVECTION DRAWS FROM A SOURCE REGION WITH MUCAPES
OF 1000-2000 J/KG...WITH 850 MB INFLOW BETWEEN 40-50 KTS. THE
GRADUAL SOUTHEAST PROPAGATION OF THE CONVECTION WILL CONTINUE
THROUGH 05Z...WITH SE DIRECTED CORFIDI VECTORS AVERAGING AROUND 10
KTS PER THE LATEST RAP GUIDANCE. MUCH OF THE MESOSCALE GUIDANCE
HAS DONE A DECENT JOB IN TERMS OF THE AXIS OF HEAVIEST
RAINFALL...INCLUDING THE RECENT HRRR AND RAP.
THROUGH 05Z...ADDITIONAL LOCALIZED RAINFALL AMOUNTS OF 2 TO 4+
INCHES ARE EXPECTED...WITH HOURLY RATES UP TO 2-2.5 INCHES...WITH
THE HEAVIEST RAINFALL EXPECTED TO SHIFT INTO NORTHERN ARKANSAS AND
SOUTHWEST TO SOUTH-CENTRAL MISSOURI. THEREAFTER...MUCAPES ARE
EXPECTED TO DROP BELOW 500 J/KG...WHILE AT THE SAME TIME MORE
PROGRESSIVE UPPER LEVEL HEIGHT FALLS AND LOW LEVEL FRONTAL MOTION
WILL INHIBIT THE BACK-BUILDING AND LEAD TO A FASTER DOWNSTREAM
MOTION OF THE HEAVIER ACTIVITY.
HURLEY
ATTN...WFO...LSX...LZK...MEG...OUN...PAH...SGF...TSA...
ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...
LAT...LON 37969057 37748946 37288901 36758916 36608938
36209008 35989143 35789350 35429543 34769738
35209778 36009704 36999484 37699249
Last Updated: 920 PM EDT WED MAR 25 2015
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