Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 040753
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
252 AM EST THU FEB 04 2016

...VALID 12Z THU FEB 04 2016 - 12Z FRI FEB 05 2016...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
25 S ASJ 35 ENE 9W7 50 E FFA 30 ESE HSE 65 SE SUT 30 SSW SUT
25 S ASJ.


...EASTERN NORTH CAROLINA...

THERE IS SOME CONCERN FOR FLOODING THROUGH THURSDAY NIGHT. RAIN
RATES MAY NOT BE QUITE ENOUGH TO EXCEED FLASH FLOOD GUIDANCE
VALUES OF 2 INCHES PER HOUR OR 3 INCHES PER 3 HOURS...BUT THOSE
GUIDANCE NUMBERS MAY COME DOWN GIVEN THE WIDESPREAD 1 TO 2 INCHES
WHICH FELL WEDNESDAY EVENING. THE SLIGHT RISK AREA WAS TRIMMED
BACK A BIT...WITH LESS EXTENSION INLAND...NOW FOCUSING MORE ON THE
OUTER BANKS. CONVECTIVE OUTFLOW WAS PUSHING OFFSHORE EARLY THIS
MORNING...AND A COLD FRONT WILL MOVE TO NEAR THE COAST EARLY
TODAY...LIKELY KEEPING SURFACE BASED INSTABILITY OFFSHORE. WPC
FAVORED THE 00Z WRF-NMM AND GEM REGIONAL FOR QPF DETAILS...AND
BOTH INDICATE THE LIKELIHOOD OF STRONG CONVECTION THIS AFTERNOON
NEAR THE OUTER BANKS...WITH OTHER SLIGHTLY ELEVATED CONVECTION
EXTENDING INLAND AS A FRONTAL WAVE BEGINS TO FORM IN THE ENTRANCE
REGION OF A VERY STRONG UPPER JET. ADDITIONAL AREAL AVERAGE
PRECIPITATION OF 1.5 TO 2.5 INCHES IS FORECAST IN THE RISK
AREA...AND IT IS POSSIBLE THAT ISOLATED LOCATIONS MAY RECEIVE
THOSE AMOUNTS OVER A 3 TO 6 HOUR PERIOD...ESPECIALLY NEAR THE
COAST.


...NORTHERN FLORIDA...

SOUTHWESTERLY LOW LEVEL FLOW WILL CONTINUE TO DRAW UP UNUSUALLY
MOIST FEBRUARY AIR OUT OF THE GULF OF MEXICO AND INTO NORTHERN
FLORIDA TODAY. INFLOW SPEEDS WILL INCREASE IN ADVANCE OF HEIGHT
FALLS ASSOCIATED WITH AN UPSTREAM SHORTWAVE TROUGH. PRECIPITABLE
WATER VALUES NEAR 1.70 INCHES ARE RUNNING AT RECORD LEVELS FOR THE
TIME OF YEAR. INSTABILITY HAD WANED AS OF EARLY MORNING...BUT THE
INCREASED LOW LEVEL WIND SPEEDS LATER TODAY MAY TAP INTO 250-750
J/KG CAPE PER NAM FORECASTS...SUPPORTING STRONG RAIN RATES IN THE
ANOMALOUSLY WARM/HUMID ENVIRONMENT. WITH LINE SEGMENTS TRAINING
AND SHOWING SLOW EASTWARD PROGRESSION...THERE IS SOME POTENTIAL
FOR RAINFALL TO EXCEED 2.5 OR 3.0 INCHES LOCALLY. BY MID TO LATE
AFTERNOON...HOWEVER...FLOW BEGINS TO VEER...AND CONVECTION MAY
PRODUCE MORE OUTFLOW...PUSHING EASTWARD MORE RAPIDLY. A SLIGHT
RISK WAS CONSIDERED HERE GIVEN THE PW ANOMALIES AND VERY HEAVY
RAIN THAT WAS OBSERVED FROM THIS WEATHER SYSTEM WEDNESDAY EVENING.
FLASH FLOOD GUIDANCE VALUES ARE SO HIGH OVER
FLORIDA...HOWEVER...THAT THE ODDS OF EXCEEDANCE AND OF SIGNIFICANT
IMPACTS APPEAR TO BE LESS THAN 5 PERCENT.

BURKE
$$




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