Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 120042
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
741 PM EST WED JAN 11 2017

...VALID 01Z THU JAN 12 2017 - 12Z THU JAN 12 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 SSW AOH 15 S AID 30 ENE HUF 20 ENE PRG 15 SE DNV LAF
10 NNW GUS 20 SSE IRS 15 NNW ADG PTK VLL 25 NNW CWAJ 20 E CWAJ
10 NNW CGF 10 SE CLE 25 NW BJJ 15 NE MNN 20 SSW AOH.


0100 UTC UPDATE

REMOVED MARGINAL RISK AREAS ACRS CA FOR THE REMAINDER OF THE
OVERNIGHT PD WITH LACK OF INSTABILITY AND DIMINISHING PWS/LOW
LEVEL UPSLOPE FORCING ACRS THE PREVIOUS OUTLOOK AREAS THROUGH THE
FOOTHILLS OF THE SIERRAS AND MTNS OF SRN CA.  GENERALLY LIGHT TO
MDT PCPN AMOUNTS ARE EXPECTED BUT HRLY AND 3 HRLY RATES ARE NOT
LIKELY TO RISE TO A LEVEL TO EXACERBATE RUNOFF ISSUES.

ACRS PARTS OF SE MI INTO NRN OH/IN...KEPT MARGINAL RISK AREA FOR
THE REMAINDER OF THE NIGHT WITH EXPANDING SHOWERS AHEAD OF COLD
FRONT IN LIGHT OF STRENGTHENING LOW LVEL JET AND POTNL TRAINING.
LATEST SPC MESOANALSIS INDICATED SOME VERY WEAK MLCAPES...GENLY
LESS THAN 500 J/KG ACRS IL INTO WRN INDIANA THAT COULD LEAD TO
SOME ISOLD EMBDD CONVECTION WITHIN THE BAND OF SHWERS.  RECENT
HRRR GUIDANCE SUGGESTS POTNL FOR SOME VERY ISOLD .50 TO 1"
AMOUNTS...SO ORGANIZED RUNOFF THREAT IS NOT VERY HIGH.  HOWEVER
GIVEN THE EXISTING LOW FFG VALUES ACRS PARTS OF THE REGION AND
POTNL FOR BRIEF TRAINING OF CELLS..HAVE MAINTAINED MARGINAL RISK
AREA ACRS THIS REGION FOR THE REMAINDER OF THE NIGHT.   SULLIVAN
PREVIOUS DISCUSSION FOLLOWS...

...SE MI...NWRN OH...NERN INDIANA...
A MARGINAL RISK AREA WAS ADDED OVER SOUTHEAST MI---NORTHWEST OH
INTO PORTIONS OF NORTHEAST INDIANA FOR POTENTIAL TRAINING OF CELLS
ALONG AND AHEAD OF THE COLD FRONT SINKING SOUTHEASTWARD FROM THE
LOWER LAKES AND TOWARD THE OH VALLEY.  STRENGTHENING LOW LEVEL
SOUTHWESTERLY FLOW WILL RAISE PW VALUES TO 2.5 TO 3.0+ STANDARD
DEVIATIONS ABOVE THE MEAN ALONG AND AHEAD OF THIS FRONT TOWARD
1200 UTC THURSDAY.   STRONG FRONTAL/PRE-FRONTAL CONVERGENCE IN
THIS ANOMALOUS PW AXIS WILL SUPPORT MODERATE TO HEAVY PRECIP
POTENTIAL ACROSS THESE AREAS.  A PERIOD OF TRAINING IN A WEST
SOUTHWEST TO EAST NORTHEASTERLY DIRECTION POSSIBLE LATE TONIGHT
INTO THURSDAY MORNING.  IN AREAS OF TRAINING---ISOLATED RUNOFF
ISSUES ARE POSSIBLE IN THE VICINITY OF SOUTHEAST MI--NORTHERN
IN---INTO NORTHEAST OH


$$





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