Quantitative Precipitation Forecast
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738
FOUS30 KWBC 241334
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
933 AM EDT SUN JUL 24 2016

...VALID 15Z SUN JUL 24 2016 - 12Z MON JUL 25 2016...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 SW DNV 10 W TIP 20 SE C75 25 NNE GYY 10 SSE GRR MBS
25 NNW CFS 15 SE P58 25 SE PHN CXHA 15 NW CLE 15 WNW DKK
10 NNE CWWZ 25 NNW ROC 10 S DSV 20 SSW BFD PIT 15 NW ZZV
10 NE DAY 15 SE DNV 10 SW DNV.


15Z UPDATE


GREAT LAKES/WESTERN NY/NORTHWEST PA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WELL ORGANIZED CONVECTIVE COMPLEX OVER LOWR MI AS OF 13Z CONTINUES
TO TRACK ESEWD ALONG STATIONARY FRONT INTO AXIS OF 1 THSD+ J/KG
MLCAPES EXTENDING INTO NRN/CNTL OH. THE WRF NMM HAS A REASONABLY
GOOD HANDLE ON CURRENT ACTIVITY AND CONTINUES TO DROP SYSTEM SEWD
INTO OH /WRN PA THIS MRNG AND AFTN WITH NEW STORMS EXPECTED TO
FIRE UPSTREAM AHEAD OF COLD FRONT DURING THE AFTN.  AT LEAST
THROUGH THE MRNG HOURS...E/W TRAINING BANDS LIKELY TO THE SOUTH OF
DVLPG MESO CIRC OVER CNTL LOWER MI COULD INCREASE RUNOFF THREAT
THROUGH LOWER MI INTO NRN OH.

SOME OF THIS REGION HAS LOWERED FLASH FLOOD GUIDANCE/SATURATED
SOILS DUE TO RECENT RAINFALL.  DESPITE THE EXPECTED FORWARD
PROPAGATION, WHICH COULD BE AT SPEEDS UP TO 35 KTS, HOURLY RAIN
RATES IN EXCESS OF 2" ARE POSSIBLE WHERE CELLS MERGE AND/OR TRAIN.
 THE MORE RELIABLE MESOSCALE GUIDANCE SHOWS LOCAL AMOUNTS IN THE
3-5" RANGE ACROSS SOUTHERN PORTIONS OF THE LOWER PENINSULA OF MI
AND AROUND 2" ACROSS WESTERN NY AND NORTHWEST PA.  THE FLOW IN
GENERAL IS DEEPLY UNIDIRECTIONAL OUT OF THE WEST, MAKING BANDS OF
TRAINING THUNDERSTORMS A DISTINCT POSSIBILITY.


FRONT RANGE OF CO EWD INTO THE KS/MO
~~~~~~~~~~~~~~~~~
UPSLOPE FLOW BEHIND A COLD FRONT COMBINED WITH SURFACE BASED CAPES
OVER 2000 J/KG DUE TO DAYTIME HEATING (PER 21Z SREF MEAN FORECAST
FIELDS) AND PRECIPITABLE WATER VALUES NEAR 1.25" ARE EXPECTED TO
INITIATE A CONVECTIVE COMPLEX IN EASTERN CO DURING DAYTIME HEATING
SUNDAY.  THERE IS A CONSISTENT SIGNAL ACROSS PORTIONS OF EASTERN
CO FOR LOCAL AMOUNTS OF 3"+. HOURLY RAIN RATES ACROSS EASTERN CO
COULD REACH/EXCEED 2", WHICH WOULD EXCEED THE LOW FLASH FLOOD
GUIDANCE VALUES SEEN IN POCKETS ACROSS EASTERN PORTIONS OF THE
STATE.  WHAT KEEPS THIS AREA A SEE TEXT RATHER THAN A SLIGHT RISK
IS THE POTENTIALLY SMALL SIZE OF IMPACT AND SOME UNCERTAINTY
REGARDING WHERE ACROSS EAST-CENTRAL OR NORTHEAST CO THE HEAVY RAIN
IS EXPECTED TO OCCUR.  BELIEVE THERE IS A BETTER CHANCE FOR THE
HEAVY RAINFALL TO FALL ACROSS EAST-CENTRAL CO THAN NORTHEAST
PORTIONS OF THE STATE.

THERE IS ALSO A THREAT OF ISOLD SMALL SCALE CONVECTIVE COMPLEXES
THAT WILL DVLP EWD ACRS KS INTO MO AS WEAK IMPULSES..SOME
CONVECTIVELY INDUCED RIDING EWD OUT ACRS CO/KS ALONG THE SRN EDGE
OF THE WLYS AND INTERACTING WITH INCREASING PWS POOLING ALONG
FRONTAL BNDRY EXPECTED TO STALL ACRS SRN KS.  WEAK BUT CONVERGENT
85H FLOW WITH PWS APCHG 2 INCHES ACRS KS/WRN MO WITH
UNIDIRECTIONAL WLY FLOW ALOFT COULD SUPPORT SOME SMALLER SCALE
TRAINING BANDS WITH SHORT TERM RAINFALL AMOUNTS OF 1 TO 2+ INCHES

SULLIVAN/ROTH
$$





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