Quantitative Precipitation Forecast
Issued by NWS

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000
FOUS30 KWBC 280649
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
249 AM EDT SUN SEP 28 2014

...VALID 06Z SUN SEP 28 2014 - 12Z MON SEP 29 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
60 E KVOA 10 ENE KVOA 15 E KVKY 10 ENE KMIS 25 NNW KMIS
35 SSE HSA 15 S GPT 15 E PQL 10 WNW NSE 30 WSW OZR DHN
15 NNE BGE 10 WSW MGR 20 SSE MGR 25 WSW VLD 20 NNW 40J 15 W 40J
40 E AAF 45 SW AAF 60 E KVOA.

WHEREAS THERE WAS DECENT MODEL QPF AGREEMENT OUT WEST..SUCH IS NOT
NECESSARILY THE CASE THRU THE GULF COAST AND SOUTHEASTERN
STATES..LEADING TO A LOWER THAN AVERAGE CONFIDENCE FORECAST.  THE
MODELS HAVE BEEN HAVING TROUBLE THRU THIS REGION FOR THE PAST DAY
OR SO..WITH 00Z GUIDANCE FROM LAST NIGHT TOO QUICK TO BRING SOME
HEAVIER RAINS INLAND..AND THIS IS THE CASE AGAIN TONIGHT WITH AT
LEAST A FEW OF THE GLOBAL MODEL QPFS..LIKELY CAUSED IN PART BY
FEEDBACK ISSUES.  GIVEN THAT THE FLOW PATTERN IS FORECAST TO
REMAIN QUITE FLAT ALOFT THIS PERIOD THRU THIS AREA..AND WITH ONLY
A VERY WEAK AREA OF LOW PRESSURE MOVING ALONG THE SURFACE BOUNDARY
THAT WILL PROBABLY REMAIN IN THE NORTHERN GULF OF MEXICO..HAVE
KEPT THE MORE SIGNIFICANT RAINS CONFINED TO NEAR THE CENTRAL AND
EASTERN GULF COAST..AT LEAST INTO MONDAY MORNING.  GAVE VIRTUALLY
NO CREDENCE TO THE 00Z GFS..OLD 12Z ECMWF HIRES AND TO A LESSER
EXTENT THE 00Z UKMET HIRES QPFS..ALL OF WHICH APPEARED TO HAVE
FEEDBACK PROBLEMS..AND INSTEAD WENT CLOSER TO THE HIRES ARW AND
NMMB..CANADIAN GEM REGIONAL AND EVEN THE NAM QPFS FOR THIS
FORECAST.  DO SEE THE POTENTIAL FOR SOME 1-2+ INCH AREAL AVERAGE
RAINS ALONG THE IMMEDIATE CENTRAL/EASTERN GULF COAST..WITH
ISOLATED HEAVIER AMOUNTS POSSIBLE.  WENT WITH A SLIGHT RISK THREAT
OF FLASH FLOODING HERE..BUT WITH THE FF GUIDANCE VALUES QUITE HIGH
AND THE POTENTIAL FOR THE HEAVIEST OF RAINS TO REMAIN OUT IN THE
GULF..DO BELIEVE ANY FLOODING CONCERNS WILL BE QUITE ISOLATED.

TERRY
$$





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