Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 131000
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
600 AM EDT SUN JUL 13 2014

...VALID 12Z SUN JUL 13 2014 - 12Z MON JUL 14 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
45 N EHA 20 W EHA 10 WSW CAO 25 SW LVS 15 NNW SAF 10 N SKX
20 WSW VTP 35 NE MYP 10 SSW APA 25 NNW LHX 45 NE LAA 45 N EHA.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 NNW POU MMU 10 SSW LOM 10 WSW MUI 25 E IPT 15 N MSV
15 NNW POU.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
40 NW LOU HAO 10 ENE VTA AGC 10 ENE CBE LWB 25 W JKL 10 S BWG
15 NW CGI 10 NNW MDH 40 NW LOU.


...PORTIONS OF THE MIDWEST AND OHIO VALLEY INTO NORTHERN MID
ATLANTIC...

AN ACTIVE PERIOD IS IN STORE FOR PORTIONS OF THE MID MISSISSIPPI
VALLEY/MIDWEST INTO SOUTHERN LOWER MI AND THE OHIO VALLEY. A RARE
JULY SYNOPTIC SETUP WITH THE ANOMALOUS DEEP UPPER LOW PIVOTING
INTO THE UPPER MISSISSIPPI VALLEY AND UPPER GREAT LAKES REGION
WILL COMBINE WITH THE FAVORABLE PRE-FRONTAL THERMODYNAMIC PROFILE
IN GENERATING WIDESPREAD CONVECTION WITH HEAVY TO IN SOME AREAS
POTENTIALLY EXCESSIVE RAINFALL AMOUNTS.  THE SHORTWAVE/VORT MAX
CUTTING UNDERNEATH A DIGGING ANOMALOUS UPPER TROUGH WILL SET THE
STAGE FOR VERY FAVORABLE RIGHT-ENTRANCE REGION UPPER JET STREAK
DYNAMICS (DEEP LAYER ASCENT) VIA A 90-110 MB 250 MB JET MAX.
MEANWHILE...1.75 TO 2.00 INCH PRECIPITABLE WATER VALUES WILL
CONTINUE TO POOL INTO THE INITIAL SURFACE FRONTAL BOUNDARY...WHICH
UNTIL MONDAY MORNING WILL REMAIN OUT AHEAD OF THE MAIN SURFACE
COLD FRONT.

THE MODELS...ESPECIALLY THE HIGHER RESOLUTION/MESOSCALE GUIDANCE
VIA THEIR SIMULATED REFLECTIVITY OUTPUT CONTINUE TO SHOW THE
MULTI-CELLULAR/ LINEAR CONVECTION ACROSS THE UPPER MIDWEST/UPPER
GREAT LAKES REMAINING PROGRESSIVE...THOUGH AS PER CURRENT RADAR
TRENDS THE CONCERN IS THAT THE TAIL END OF THE ACTIVITY WILL GET
HUNG UP SOMEWHAT ALONG THE EASTERN NE/KS...IA/MO BORDERS INTO
IL...OR ESSENTIALLY ALONG THE PORTION OF THE FRONT THAT IS MORE
W-E ORIENTED (MORE PARALLEL TO THE MEAN FLOW). FARTHER
NORTH...WITH THE STRONGER WESTERLY 0-6KM BULK SHEAR WITH MORE OF A
SW-NE ORIENTED SURFACE FRONT...EXPECT THE CONVECTION TO CONTINUE A
SWIFT EASTWARD PROGRESSION...THUS ANTICIPATE THE EXCESSIVE
RAINFALL RISK TO DIMINISH QUICKLY ACROSS LOWER MI AND NORTHERN
PORTIONS OF THE OH VALLEY THIS MORNING.

BY THIS AFTERNOON INTO TONIGHT...THE ATTENTION WILL TURN TO
EASTERN PORTIONS OF THE MID MISSISSIPPI VALLEY INTO THE OH VALLEY
AND NORTHERN PORTIONS OF THE MID ATLANTIC...WHERE AS PER THE SETUP
CURRENTLY UPSTREAM OF THIS AREA...THE SURFACE BOUNDARY WILL BECOME
MORE PARALLEL TO THE MEAN LOW-MID LEVEL FLOW THAN OTHERWISE. THE
AFOREMENTIONED ANOMALOUS DYNAMICAL SUPPORT (STRENGTHENING RIGHT
ENTRANCE REGION UPPER DIVERGENCE AND LOW-MID LEVEL FRONTOGENESIS)
WITH THE STRONG HEIGHT FALLS INTO THE NORTHERN TIER STATES (500 MB
ANOMALIES 3-3.5 STANDARD DEVIATIONS BELOW NORMAL) WILL BE
JUXTAPOSED WITH A MOISTURE-RICH ENVIRONMENT AS PWATS REMAIN NEAR
2.00 INCHES. THIS WILL ALLOW FOR POTENTIALLY EXCESSIVE RAINFALL
RATES...LOCALLY OVER 2 INCHES PER HOUR...ESPECIALLY DURING THE
AFTN/EVENING WITH MUCAPES IN THE 1000-2000 J/KG RANGE.
MOREOVER...AS THE WSW LOW LEVEL INFLOW INCREASES AND BECOMES
NEARLY ALIGNED WITH THE 850-300 MB FLOW OVERNIGHT...THE MODELS
SHOW CORFIDI VECTORS WEAKENING WHILE HAVING MORE OF AN EASTERLY
COMPONENT (OPPOSITE OF THE CELL MOTIONS)...SUGGESTIVE OF UPWARD
PROPAGATION AND THUS BACK-BUILDING/TRAINING OF CONVECTION. WPC
NOTED AREAL-AVERAGE QPF BETWEEN 1 AND 2.5+ INCHES FROM SRN IL/IN
EASTWARD THROUGH NRN KY...SRN OH...AND CENTRAL/NRN WV...THOUGH
MUCH OF THE HIGHER RESOLUTION GUIDANCE SHOW ISOLATED AMOUNTS OVER
4 INCHES.


...CENTRAL-SOUTHERN CO/NORTHERN NM/WESTERN KS...

THE TAIL END OF A SURFACE TROUGH SINKING SOUTH DOWN THE FRONT
RANGE OF THE CENTRAL ROCKIES AND WEAK SHORT WAVE DYNAMICS DROPPING
SOUTH AND EAST THROUGH ERN CO ON THE ERN SIDE OF THE GREAT BASIN
RIDGE WILL ALLOW FOR LINGERING MODERATE-HEAVY RAINFALL EARLY THIS
MORNING WITH THE POTENTIAL FOR ADDITIONAL LOCALIZED FLASH
FLOODING. THIS GIVEN THE PERSISTENT HIGH PWATS...AROUND 2 STANDARD
DEVIATIONS ABOVE AVG...ALONG WITH THE EASTERLY (UPSLOPE) FLOW.
MEANWHILE...THE CONTINUED MOIST ENVIRONMENT (PWATS 1-1.25+ INCHES)
ALONG WITH THE LLVL EASTERLY UPSLOPE FLOW AND WEAK INSTBY (MUCAPES
~500 J/KG) WILL LIKELY GENERATE ADDITIONAL SCATTERED/NUMEROUS
CONVECTIVE CLUSTERS THIS AFTN/EVENING AND AGAIN INTO THE OVERNIGHT
PERIOD. WHILE THE AREAL-COVERAGE OF THE HEAVIER RAIN CORES IS NOT
EXPECTED TO BE AS WIDESPREAD...THE POTENTIAL WILL EXIST FOR
ADDITIONAL...MORE ISOLATED AREAS OF EXCESSIVE RAINFALL
AMOUNTS...PARTICULARLY SINCE THE FLASH FLOOD GUIDANCE VALUES HAVE
LOWERED FOLLOWING THE RECENT ACTIVITY.

HURLEY
$$




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