Quantitative Precipitation Forecast
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000
FOUS30 KWBC 242205
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
503 PM EST WED DEC 24 2014

...VALID 00Z THU DEC 25 2014 - 00Z FRI DEC 26 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


...SOUTHERN AND EASTERN NEW ENGLAND...

THE DEEP LAYERED SOUTHERLY FLOW PATTERN AHEAD OF A HIGH AMPLITUDE
MID/UPPER TROF WILL CONTINUE TO DRAW UNSEASONABLY DEEP MSTR
NORTHWARD UP THE EAST COAST..LEADING TO WIDESPREAD RAIN.
PRECIPITABLE WATER VALUES EXCEEDING 1.5 INCHES ON THE 12Z WALLOPS
VA SOUNDING AND MOVING UP INTO NEW COASTAL NEW ENGLAND ARE A VERY
IMPRESSIVE 4 TO 4.5 STANDARD DEVIATIONS FROM CLIMATOLOGY.
FURTHER...SOME CONVECTIVE ENHANCEMENT IS EXPECTED...AND WAS
ALREADY OBSERVED PER RADAR IMAGERY OVER SOUTHERN NEW ENGLAND. RAP
FORECAST SOUNDINGS SUPPORT SHALLOW CONVECTION EARLY THIS EVENING
AND PERHAPS AGAIN AROUND 04-06 UTC WITH THE ARRIVAL OF A LOW LEVEL
SPEED MAXIMUM THAT HAD AIDED HEAVY RAINFALL PRODUCTION OVER NORTH
CAROLINA DURING THE EARLY AFTERNOON. SOME TRAINING OF MODERATE TO
ISOLATED HEAVIER RAIN COULD LEAD TO SOME VERY LOCAL RUNOFF
PROBLEMS MAINLY FROM NORTHERN NJ INTO EASTERN NEW ENGLAND. EVEN
WITH CONVECTIVE ENHANCEMENT...THE EVENT WILL EVOLVE VERY QUICKLY
AND WITH RAPID INDIVIDUAL STORM MOTION...SUCH THAT RAINFALL TOTALS
WILL BE CAPPED...AND UNLIKELY TO EXCEED FLASH FLOOD GUIDANCE
VALUES ON MORE THAN AN ISOLATED BASIS. SOME LOCAL 1 INCH RAINS
FALLING OVER A COUPLE OF HOURS IS POSSIBLE..WHICH COULD LEAD TO
FLASH FLOODING OF THE MOST SUSCEPTIBLE FLOOD PRONE AREAS.

TERRY/BURKE
$$




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