Quantitative Precipitation Forecast
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FOUS30 KWBC 300813
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
411 AM EDT SAT MAY 30 2015

...VALID 12Z SAT MAY 30 2015 - 12Z SUN MAY 31 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 SSW AOH 15 S IND 10 WNW AJG 10 WSW FWC 20 SW MVN 25 W MDH
20 NNE FAM SUS IJX 15 NNW PNT LWA 15 N RNP 20 ESE CFS 25 NE CTZR
CWSN 35 S CWSN 25 SE CWAJ 35 NNW MFD 15 SSW AOH.

...MID MS VALLEY/MIDWEST INTO THE LOWER GREAT LAKES...

THE MAIN WEATHER MAKER THIS PERIOD..AT LEAST FROM THE MID MS
VALLEY AND MIDWEST INTO THE LOWER GREAT LAKES..WILL BE THE WELL
DEFINED MCV NOW LIFTING NORTHEASTWARD THRU WESTERN AR.  THIS
SYSTEM WILL CONTINUE TO MOVE NORTHEASTWARD INTO THE LOWER GREAT
LAKES BY SUNDAY MORNING..AHEAD OF A PROGRESSIVE/GENERALLY EASTWARD
MOVING H5 TROF NOW SITUATED OVER THE CENTRAL PLAINS.  IN ADVANCE
OF THIS MCV..A MODEST SOUTHERLY LOW LEVEL JET WILL BRING
INCREASING MOISTURE NORTHWARD..WITH PWS FORECAST TO INCREASE TO
GREATER THAN 1.75 INCHES UP THRU THE OH VALLEY..MIDWEST AND INTO
THE LOWER GREAT LAKES.  LARGE SCALE LIFT WITH THIS MCV ALONG WITH
THE DEEP MOISTURE WILL SUPPORT ORGANIZED AND HEAVY
CONVECTION/RAINS THRU THE MID MS VALLEY AND MIDWEST..AND
ESPECIALLY SO FROM PARTS OF THE MIDWEST INTO THE LOWER GREAT
LAKES..WHERE THE MCV AND MOISTURE WILL INTERACT WITH THE FRONTAL
BOUNDARY PUSHING THRU.  FOR THE MOST PART THE LATEST MODEL RUNS
ARE IN DECENT AGREEMENT IN THEIR HANDLING OF THE MCV..ALTHOUGH IT
APPEARS THE GFS MAY BE SUFFERING A BIT FROM FEEDBACK
PROBLEMS..RESULTING IN A HEAVIER AND SLIGHTLY FARTHER NORTH QPF AS
COMPARED TO THE REMAINDER OF THE GUIDANCE.  WILL STRAY AWAY FROM
THE GFS AT THIS TIME.  STILL..EXPECT AT LEAST SOME WIDESPREAD 1-2+
INCH RAINFALL AMOUNTS WITH THIS MCV AND SOME
2-3+ INCH TOTALS WHERE IT INTERACTS WITH THE FRONTAL
BOUNDARY..WITH EVEN SOME ISOLATED HIGHER AMOUNTS POSSIBLE.  FF
GUIDANCE VALUES GENERALLY ON THE HIGHER SIDE HERE..SO KEPT THE
FLOODING THREAT IN THE SLIGHT RISK CATEGORY.


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 ESE CRS 10 SW GDJ SEP 25 WSW MWL 20 SE RPH DTO 10 WNW SLR
30 ESE OSA 25 WNW SHV 25 W SHV 20 S GGG 10 ESE CRS.

...PARTS OF TX...

THE UNSETTLED AND RAINY PATTERN WILL PERSIST THRU THIS PERIOD FOR
MUCH OF TX EXCEPT THE PANHANDLE..BUT WITH EXPECTED RAINFALL
AMOUNTS NOT AS HEAVY AS WE`VE SEEN RECENTLY.  A SLIGHT DRYING
TREND..AT LEAST MOISTURE AND PW-WISE..WAS NOTED OVER MUCH OF TX
THIS EVENING BEHIND THE AR MCV AND ITS TRAILING SHEAR AXIS DOWN
INTO THE LOWER MS VALLEY.  THIS SLIGHT DRYING TREND..ALONG WITH
THE DEVELOPMENT OF A NORTHWESTERLY MID/UPPER LEVEL FLOW REGIME
WHICH SHOULD ALLOW FOR A MORE PROGRESSIVE CONVECTIVE
PATTERN..SHOULD HOPEFULLY TRANSLATE INTO THOSE LIGHTER RAINFALL
AMOUNTS..ESPECIALLY AS WE GET FARTHER INTO THE DAY 1 PERIOD.  THAT
SAID..CONVECTION IS STILL GOING TO BE RATHER ORGANIZED AND WILL
IMPACT MUCH OF TX THIS PERIOD..TRIGGERED BY S/WV ENERGY DROPPING
SOUTHEASTWARD OUT OF THE SOUTHERN ROCKIES THRU THE STATE.  SOME
EAST-WEST CONVECTION WHICH MAY HANG UP BRIEFLY INTO THE SATURDAY
MORNING HOURS THRU NORTHERN TX AHEAD OF THE DEVELOPING MCV BACK
OVER WESTERN TX AT THIS TIME..AND WILL LIKELY  PRODUCE SOME
LOCALLY HEAVIER RAINFALL AMOUNTS BEFORE THE FRONTAL PASSAGE
SATURDAY AFTERNOON LESSENS THE LOCALLY HEAVY RAINFALL POTENTIAL
HERE.  KEPT A SMALL SLIGHT RISK THRU NORTHERN TX ASSOCIATED WITH
THIS MCV..GIVEN THE SATURATED CONDITIONS IN PLACE.  FROM LATER
SATURDAY AFTERNOON INTO SATURDAY NIGHT..ANY HEAVIER RAINFALL
THREAT IS LIKELY TO SHIFT INTO SOUTHEASTERN TX..WHERE THE HIGHER
PWS WILL PERSIST UNTIL THE FRONTAL PASSAGE LATER SATURDAY NIGHT.
KEPT AREAL AVERAGE RAINFALL AMOUNTS HERE GENERALLY IN THE
0.50-1.00 INCH RANGE..BUT SOME LOCALLY HEAVIER TOTALS CERTAINLY
POSSSIBLE.


TERRY


$$




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