Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 250032
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
731 PM EST FRI FEB 24 2017

...VALID 01Z SAT FEB 25 2017 - 12Z SAT FEB 25 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 ESE BMG LAN 30 NE MBS 45 NE P58 25 S CWSN BJJ LHQ 35 ENE LEX
25 SW LEX 35 ESE FTK 10 S SDF 10 ESE BMG.


0100 UTC UPDATE

EXCESSIVE RAIN THREAT REMAINS MARGINAL ACRS PORTIONS OF LOWER MI
SWD INTO KY WITH BOTH PREFRONTAL AND FRONTAL CONVECTION BANDS
HAVING BECOME A BIT MORE ACTIVE EARLY FRI EVENING. CELL MOTION
REMAINS FAIRLY QUICK TO THE NE BUT SOME ORGANIZED LINEAR ELEMENTS
HAVE DEVELOPED ESPECIALLY IN THE PREFRONTAL BAND FROM WRN OH SWD
INTO KY.  THESE STORMS CONTINUE TO DVLP WITHIN AN AXIS OF 500 TO
1000 J/KG ML CAPES AND 3+ STD PW ANAMOLIES...THOUGH ADMITTEDLY THE
WARM SECTOR AIRMASS IS MORE TYPICAL OF MAY IN WHICH CASE THE PW
ANOMLIES WOULD BE CONSIDERED ONLY MARGINALLY.  THAT SAID...DECENT
MID/UPR HEIGHT FALLS TO GO ALONG WITH FAVORABLE INSTABILITY FOR
THIS TIME OF YEAR COULD CONTINUE TO SUPPORT SOME STRONG
TSTMS/BANDS OVERNIGHT WITH POTNL FOR SOME SHORT TERM TRAINING
WITHIN THE MORE ORGNAIZED BANDS.  FOR MOST AREAS...STORMS SHOULD
REMAIN PROGRESSIVE ENOUGH AND SHORT TERM RAINFALL RATES LOW ENOUGH
TO PRECLUDE A LARGER ORGANIZED HEAVY TO EXCESSIVE RAINFALL THREAT.

SULLIVAN   PREVIOUS DISCUSSION FOLLOWS...

..LOWER MICHIGAN / INDIANA / OHIO / KENTUCKY...

A DEEP SURFACE LOW WILL TRACK FROM MISSOURI THIS MORNING TOWARD
LOWER MICHIGAN BY EVENING. PRECIPITABLE WATER VALUES JUST OVER ONE
INCH WILL STRETCH OUT AHEAD OF THE ASSOCIATED COLD FRONT...PUSHING
SOMEWHAT ANOMALOUS MOISTURE INTO THE OHIO VALLEY AND LOWER GREAT
LAKES. UNUSUALLY WARM AIR IN THE WARM SECTOR COMBINED WITH
SEASONABLY COLD AIR ALOFT WILL YIELD MODEST CAPE VALUES AT LEAST
500 J/KG IN MOST HI-RES GUIDANCE...AND UP TO 1000 J/KG IN SOME
GUIDANCE. THE HEAVIER AMOUNTS OF EVENT-TOTAL RAINFALL...EXCEEDING
ONE INCH AREAL AVERAGE...WILL OCCUR OVER SOUTHERN AND EASTERN
LOWER MICHIGAN. DEEP LAYER FORCING WILL BE ESPECIALLY LONG LIVED
HERE...WITH WARM ADVECTION FOLLOWED LATER BY STRONG HEIGHT FALLS.

CONFIDENCE IN QPF PLACEMENT IS HIGHEST IN THE COLD SECTOR...AND
ALONG THE NOSE OF THE LOW LEVEL JET INTO LOWER MICHIGAN. FARTHER
SOUTH IT WILL BE DIFFICULT TO ACCURATELY CAPTURE MULTIPLE NARROW
SWATHS OF HEAVIER PRECIPITATION FROM THE OUTBREAK OF STRONG TO
SEVERE STORMS EXPECTED PER THE STORM PREDICTION CENTER DAY 1
OUTLOOK. RAPID STORM MOTION WILL LIMIT OVERALL RAINFALL
POTENTIAL...BUT UNSEASONABLY RICH MOISTURE AND INSTABILITY ARGUE
FOR RESPECTABLE SHORT TERM RAIN RATES WITH ACCUMULATIONS OVER A
HALF INCH IN ONE HOUR OR ONE INCH IN 2-3 HOURS. ADDITIONALLY...AS
THE UPPER TROUGH FURTHER AMPLIFIES TOWARD BECOMING NEUTRALLY
TILTED...THERE SHOULD BE SOME POTENTIAL FOR SHORT TERM BOUTS OF
TRAINING CONVECTION...PARTICULARLY OVER PARTS OF
IN/OH/KY/MI...WHERE CORFIDI VECTORS AND SUPERCELL MOTION DO NOT
DEVIATE MUCH FROM THE 0-6 KM MEAN WIND. WHEREVER TRAINING OCCURS
FLASH FLOOD GUIDANCE COULD BE EXCEEDED.

BURKE
$$




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