Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FOUS30 KWBC 110847
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
446 AM EDT FRI JUL 11 2014

...VALID 06Z FRI JUL 11 2014 - 12Z SAT JUL 12 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
MNH 35 N ALS 15 SSW CPW 20 NW DRO 35 ENE 4BL 35 SE CNY 10 N CNY
10 WNW U28 40 W U28 55 NNE BCE 40 E MLF 35 ENE U24 25 ENE DPG
15 ENE OGD 20 NE FIR 10 S RKS 30 WSW PAT 20 N DRC 40 SW CUT
10 WNW IEN 25 ESE IEN 30 SE IEN 25 S IEN 30 N AIA AIA 20 ENE BFF
20 E BFF 35 SSE AIA 25 NW OGA 10 NE OGA 15 NNE IML 35 ENE AKO
35 SSE AKO 20 NNW LIC MNH.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 NNE DBQ 10 SSE RPJ PNT 10 NE PIA 20 NE BRL PEA ADU
30 ENE OFK 30 NNW OFK 35 ENE ONL 30 N ONL 30 SSE ICR 10 SSE ICR
35 SE 9V9 OTG 25 NNE CCY 20 NNE DBQ.


...PORTIONS OF THE SOUTHWEST...EASTERN GREAT BASIN...CENTRAL
ROCKIES...AND CENTRAL HIGH PLAINS...

WATER VAPOR IMAGERY EARLY FRI MORNING CONTINUES TO SHOW A MOISTURE
PLUME STRETCHING FROM NORTHWEST MEXICO INTO THE SOUTHWEST AND
GREAT BASIN ON THE SOUTH AND WEST SIDES OF THE GREAT BASIN UPPER
HIGH. IN ADDITION...THE WV IMAGERY CLEARLY SHOWS AN UPPER LEVEL
SHORTWAVE TROUGH ALONG THE SRN CA/SRN NV/WRN AZ BORDER...A FEATURE
THAT FOCUSED MORE ORGANIZED CONVECTION ACROSS SRN NV AND NW AZ
DURING THE PEAK HEATING HOURS THURSDAY. AS THIS MCV LIFTS SLOWLY
NE INTO THE CENTRAL GREAT BASIN TODAY...THE DYNAMICAL SUPPORT
PRECEDING IT WILL GENERATE MORE ORGANIZED ACTIVITY ACROSS NRN UTAH
(ESPECIALLY NE UTAH)...WITH ADDITIONAL CONVECTION TRAILING ALONG
THE SOUTHERN FLANK OF THE VORT LOBE/SHEAR AXIS ACROSS WRN CO...ERN
AZ...AND WRN NM...WITH CONVECTION EVENTUALLY OVERSPREADING WY AND
AREAS EAST INTO THE HIGH PLAINS (INTO WRN NE) LATER TODAY AND THIS
EVENING AS THE VORT GETS PICKED UP BY THE STRONGER WESTERLIES AND
MOVES QUICKLY EASTWARD INTO THE NEBRASKA/SOUTH DAKOTA BORDER BY
12Z SAT. DEEP-LAYER INSTBY OVER THIS REGION WILL BE MARGINAL YET
SUFFICIENT FOR ORGANIZED CONVECTION (MUCAPES 500-1000 J/KG)...AND
GIVEN THE DYNAMICAL SUPPORT AND PRECIPITABLE WATER VALUES OF 1-1.5
INCHES (HIGHEST OVER WRN NE...IN ALL AREAS NEAR 3 STANDARD
DEVIATIONS ABOVE THE NORM)...EXPECT UNSEASONABLY HIGH
AREAL-AVERAGE QPF AMOUNTS OF .25 TO .50 INCHES ACROSS PORTIONS OF
EAST-CENTRAL AZ...WRN NM...WRN CO...NE UT...EASTERN WY...AND WRN
NE...WITH HIGHEST AMOUNTS (AVERAGING .5 TO 1 INCH) ACROSS THE
CENTRAL ROCKIES FROM NORTH-CENTRAL CO/SOUTH-CENTRAL WY INTO THE
HIGH PLAINS OF NE CO/SE WY AND WRN NE. AS PER THE HIGHER
RESOLUTION GUIDANCE...ISOLATED HEAVIER AMOUNTS OF 2-3+ INCHES ARE
EXPECTED...WHICH GIVEN THE POTENTIAL RAINFALL RATES COULD RESULT
IN RUNOFF ISSUES AND LOCALIZED FLASH FLOODING IN AREAS OF LOWER
FFG.

...NORTHEAST NEBRASKA/SOUTHEAST SOUTH DAKOTA EASTWARD THROUGH
NORTHERN IOWA AND NORTHWEST ILLINOIS...

MULTIPLE CONVECTIVELY-ENHANCED...MID-LEVEL SHORTWAVES ALONG A
QUASI-ZONAL FLOW PATTERN ON THE NORTHERN PERIPHERY OF THE FLAT
UPPER RIDGE/SOUTHERN END OF THE FASTER WESTERLIES WILL MAKE FOR
MULTIPLE ROUNDS OF CONVECTION ALONG/AHEAD OF A SLOW MOVING W-E
SURFACE BOUNDARY...ONE THAT WILL DROP SLOWLY SOUTHWARD ACROSS DAY
1 (INTO NRN PTNS OF THE CENTRAL PLAINS AND MID MS VLY) AIDED BY
THE CONVECTIVE OUTFLOWS. THERE REMAINS SOME CONCERN ABOUT MORE
ORGANIZED...ELEVATED CONVECTION (MCS ACTIVITY) OVERNIGHT FRI-INTO
EARLY SAT AS THE LLJ STRENGTHENS TO AROUND 40 KTS...PARTICULARLY
ACROSS NORTHERN NEBRASKA/SOUTHERN SOUTH DAKOTA INTO IOWA AND
NORTHERN ILLINOIS WHERE THE MODELS CONTINUE TO SHOW A COMPACT AREA
OF RICH AVAILABLE MOISTURE (AREA OF MAXIMUM PRECIPITABLE WATER
VALUES BTWN 1.75-2.00 INCHES) TRAVERSING THE AREA. MUCAPES
PERSISTING AOA 2000 J/KG OVERNIGHT PER THE 00Z ARW WOULD SUPPORT
THE POSSIBILITY OF SOME HEAVY RAINFALL OVER THESE AREAS
OVERNIGHT...THOUGH GIVEN THE DEGREE OF DEEP LAYER SHEAR THE
LIKELIHOOD OF MORE FORWARD (DOWNWIND) PROPAGATION THAN OTHERWISE
SHOULD LIMIT THE THREAT FOR ORGANIZED AREAS OF EXCESSIVE RAINFALL.
WPC CONTINUED TO UTILIZE A MULTI-MODEL BLEND WITH THE QPF
(INCLUDING THE HIGHER RES GUIDANCE)...WITH MAXIMUM AREAL AVERAGE
AMOUNTS OF .50 TO 1 INCH OVER SOUTHEAST WYOMING EAST THROUGH
NORTHERN NEBRASKA/SOUTHEAST SOUTH DAKOTA...NORTHERN IOWA... AND
NORTHERN ILLINOIS. OVER THESE REGIONS...SOME OF THE MESOSCALE
GUIDANCE YIELDS ISOLATED AMOUNTS OVER 4 INCHES.

HURLEY
$$




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.