Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 040810
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
409 AM EDT WED MAY 04 2016

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




CENTRAL TO SOUTH FLORIDA

CONVECTION EXPECTED TO ENHANCE ACROSS CENTRAL TO SOUTH FLORIDA
WEDNESDAY ALONG AND AHEAD OF THE SURFACE COLD FRONT FORECAST TO
SINK SOUTHEASTWARD ACROSS THE PENINSULA.  STRENGTHENING WEST
SOUTHWESTERLY LOW LEVEL FLOW OFF OF THE GULF OF MEXICO WILL RAISE
PW VALUES TO 2 TO 3 STANDARD DEVIATIONS ABOVE THE MEAN ALONG AND
AHEAD OF THE FRONTAL BOUNDARY.  THIS ALONG WITH ENHANCED UPPER
DIFFLUENCE MOVING ALONG THE FRONTAL BOUNDARY DURING THE FIRST HALF
OF THIS FORECAST PERIOD WILL SUPPORT POTENTIAL FOR WIDESPREAD
HEAVY RAINFALL AMOUNTS ACROSS THE CENTRAL TO SOUTHERN PORTION OF
THE PENINSULA.  THERE MAY BE TRAINING OF CELLS IN THE DEEP LAYERED
WEST SOUTHWESTERLY FLOW ALONG AND AHEAD OF THE FRONTAL BOUNDARY.
WHILE FFG VALUES ARE HIGH ACROSS CENTRAL TO SOUTH
FLORIDA---ISOLATED RUNOFF ISSUES ARE POSSIBLE IN URBANIZED AREAS
ALONG THE WEST CENTRAL TO SOUTHWEST COAST AND THE EAST CENTRAL TO
SOUTHEAST COAST WHERE TRAINING OCCURS.

CENTRAL APPALACHIANS INTO THE EASTERN UPSLOPE AREAS OF THE CENTRAL
APPALACHIANS

CONCERNS FOR HEAVY RAINFALL AND ISOLATED RUNOFF ISSUES WILL BE
TOWARD THE END OF THIS FORECAST PERIOD---IN THE EARLY MORNING
HOURS OF THURSDAY---ACROSS THE CENTRAL APPALACHIANS INTO THE
EASTERN UPSLOPE AREAS OF THE CENTRAL APPALACHIANS.  SHORTWAVE
ENERGY OVER THE UPPER LAKES/UPPER MS VALLEY REGION EXPECTED TO
DROP SOUTHEASTWARD THIS PERIOD---AMPLIFYING INTO A CLOSED LOW
MOVING ACROSS THE OH VALLEY AND TOWARD THE CENTRAL TO SOUTHERN
APPALACHIANS.  TOWARD THE END OF THE FORECAST PERIOD EARLY
THURSDAY MORNING---A COMMA HEAD DEFORMATION PRECIP BAND MAY
DEVELOP ACROSS THE CENTRAL APPALACHIANS INTO THE EASTERN UPSLOPE
AREAS OF THE APPALACHIANS FROM WV INTO NW VA...FAR WESTERN MD.
PRECIP MAY PIVOT WITH THIS COMMA HEAD AREA AND REMAIN STATIONARY
FOR SEVERAL HOURS EARLY THURSDAY ACROSS THESE AREAS.  CONFIDENCE
NOT GREAT WITH EXACT PLACEMENT OF WHERE THIS WILL BE--BUT THERE IS
A GENERAL MODEL CONSENSUS IN THE VICINITY OF WV INTO NW VA AND FAR
WESTERN MD.  WITH FFG VALUES RELATIVELY LOW ACROSS THESE
AREA---ISOLATED RUNOFF ISSUES MAY DEVELOP IN AREAS WHERE THE
PRECIP HANGS UP EARLY THURSDAY MORNING.

ORAVEC
$$





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