Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 301411
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1009 AM EDT SUN AUG 30 2015

...VALID 15Z SUN AUG 30 2015 - 12Z MON AUG 31 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


AFTER LOOKING AT RECENT OBSERATIONAL DATA AND SOME OF THE RECENT
HIRES QPF GUIDANCE..SEE NO REASON TO DEVIATE FROM EARLIER
THINKING/REASONING REGARDING THE HEAVY RAINFALL POTENTIAL OVER THE
SOUTHEASTERN STATES.

PREVIOUS DISCUSSION FOLLOWS...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
40 SW KEY 70 SW APF 55 W APF 50 WSW PGD 30 S SRQ 20 WNW PGD
10 SSE PGD 15 NNE APF 30 SE APF 25 WSW TMB 10 NW TMB 10 NNW HWO
10 ESE BCT 20 ESE PMP 25 ESE MIA 25 E MTH 40 SSE NQX 40 SSW KEY
40 SW KEY.

...SOUTHEAST AND SOUTHWEST FLORIDA COASTAL REGIONS...

WIDESPREAD HEAVY RAINS LIKELY THIS PERIOD ACROSS CENTRAL TO SOUTH
FLORIDA AS MUCH ABOVE AVERAGE PW VALUES WILL CONTINUE TO BE DRAWN
NORTHEASTWARD ON THE SOUTHEAST SIDE OF THE MID TO UPPER LEVEL
CLOSED LOW OVER THE NORTH CENTRAL GULF.   STRENGTHENING
SOUTHEASTERLY TO SOUTHERLY LOW LEVEL FLOW AND FAVORABLE UPPER
DIFFLUENCE TO THE SOUTHEAST OF THE CLOSED LOW AND AHEAD OF ANY LOW
TO MID LEVEL VORTS COMING OUT OF THE TROPICS ASSOCIATED WITH THE
REMNANTS OF ERIKA WILL SUPPORT POTENTIAL FOR WIDESPREAD HEAVY
PRECIP TOTALS IN THIS MUCH ABOVE AVERAGE PW AXIS OVER CENTRAL TO
SOUTH FLORIDA.  WHILE THERE IS A LOT OF QPF DETAIL DIFFERENCES
AMONG THE MODELS---THERE IS A DEFINITE SIGNAL FOR HEAVY TO
ISOLATED URBAN RUNOFF ISSUES ACROSS THE SOUTHEASTERN AND
SOUTHWESTERN COASTAL REGIONS OF FLORIDA---INCLUDING THE KEYS.



SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
35 E NRB 10 NW SGJ 10 NW VQQ 30 WNW JAX 30 ESE AYS 25 ESE JYL
40 WSW MYR 15 SW MYR 45 E CHS 65 SSE CHS 75 SE HXD 35 E NRB.

...COASTAL SOUTHEAST...

CONCERNS FOR VERY HEAVY TO ISOLATED EXCESSIVE RAINFALL AMOUNTS
ALSO ALONG THE COASTAL SOUTHEAST FROM FAR NORTHEAST FL THROUGH
COASTAL GEORGIA AND MOST OF COASTAL SOUTH CAROLINA.   SEPARATE
FROM ANY REMNANTS OF ERIKA AFFECTING SOUTH FLORIDA---HIGH PW
VALUES AND FAVORABLE UPPER DIFFLUENCE WILL ALSO BE PUSHING
NORTHEASTWARD ON THE EASTERN SIDE OF THE NORTH CENTRAL GULF COAST
UPPER LOW---INTO THE COASTAL SOUTHEAST.  MODELS ARE SHOWING SOME
DIFFERENCES WITH RESPECT TO HOW FAR AND FAST HEAVY PRECIP TOTALS
PUSH NORTHEASTWARD ALONG THE SOUTHEAST COAST.  THERE
IS--HOWEVER---GENERAL AGREEMENT FOR HEAVY TO ISOLATED EXCESSIVE AT
LEAST REACHING COASTAL AREAS OF THE SOUTHEAST---POSSIBLY EXTENDING
FARTHER INLAND.  WPC DID LEAN TOWARD THE FARTHER INLAND HEAVY RAIN
SOLUTIONS OF THE ECMWF---UKMET AND NSSL WRF GIVEN THE STRONG
UPSTREAM CLOSED LOW INITIALLY OVER THE NORTH CENTRAL GULF THAT
WILL BE PRESSING NORTHEASTWARD.

ORAVEC/TERRY
$$





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