WPC Met Watch |
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Mesoscale Precipitation Discussion: #0217 (2014) |
(Issued at 713 PM EDT MON JUL 21 2014
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MPD Selection |
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MESOSCALE PRECIPITATION DISCUSSION 0217
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
713 PM EDT MON JUL 21 2014
AREAS AFFECTED...EAST CENTRAL ND INTO NWRN MN
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 212214Z - 220614Z
SUMMARY...A SWATH OF VERY HEAVY RAINFALL IS ANTICIPATED FROM EAST
CENTRAL NORTH DAKOTA INTO NORTHWESTERN MINNESOTA THE NEXT SEVERAL
HOURS... IN CONJUNCTION WITH THE ACTIVE SEVERE WEATHER IN A VERY
DIFLUENT UPPER-LEVEL PATTERN.
DISCUSSION...LATEST COMBINED WATER VAPOR/IR SAT IMAGERY SHOWS VERY
COLD CLOUDS TOPS DEVELOPING OVER CENTRAL NORTH DAKOTA THIS
AFTERNOON. THIS IS IN ASSOCIATION WITH A WEAK SHORT WAVE/500MB
IMPULSE RACING ACROSS THE NRN TIER OF AN IMPRESSIVE UPPER RIDGE
FURTHER SOUTH OVER THE PLAINS. AN INTENSE BAND OF CONVECTIVE HEAVY
RAIN HAS ALREADY DEVELOPED ALONG AND AHEAD OF A QUASI-STATIONARY
FRONT FROM BIS TO NORTHWEST MN AND SHOULD CONTINUE TO THRIVE OVER
THE NEXT SEVERAL HOURS. THE COMBINATION OF IMPRESSIVE
INSTABILITY... IDEAL UPPER JET COUPLING AND ANOMALOUS LOW LEVEL
MOISTURE POOLING ALL WITHIN THIS CORRIDOR SHOULD RESULT IN
CONTINUING INTENSE RAIN RATES DESPITE THE VERY PROGRESSIVE NATURE
OF THE PATTERN. SOME MODELS INDICATE POSSIBLE SLIGHT TRAINING FROM
NORTHEASTERN ND TO NORTHWESTERN MN WILL BE POSSIBLE LATER
TONIGHT... AS THE 850MB FLOW BEGINS TO PARALLEL THE 250MB WESTERLY
COMPONENT. THIS COULD RESULT IN SOME BACKBUILDING ON THE BACK END
OF THE MESO SYSTEM BUT THIS APPEARS UNLIKELY AT THE MOMENT WITH
THE PROGRESSIVE NATURE OF THE UPPER PATTERN. THE MODEL GUIDANCE...
GLOBAL AND HI-RES... SUGGEST 2-4" AREAL AVERAGE AMOUNTS WITH
LOCALLY HIGHER VALUES BUT THIS MAY BE UNDERDONE.
MUSHER
ATTN...WFO...DLH...FGF...BIS...
ATTN...RFC...MBRFC...NCRFC...
LAT...LON 46279995 46710061 47540059 48439989 48989865 49039626
48999372 48129358 46909623 46469871 46279995
Last Updated: 713 PM EDT MON JUL 21 2014
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