Quantitative Precipitation Forecast
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FOUS30 KWBC 062036
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
435 PM EDT MON JUL 06 2015

...VALID 21Z MON JUL 06 2015 - 12Z TUE JUL 07 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 E FCS 20 NNE TAD 45 SE TAD 20 S CAO 25 N BGD PTT 20 E TNU
30 E MKE 20 ENE GYY 15 NNE BLV 10 NW OKM 20 SSW DUC 25 NNE ABI
20 SSW BPG 25 SSE HOB 25 ESE ROW 15 NW ATS 40 WSW ATS 25 SE ALM
15 SW HMN 20 ENE TCS 15 NE GNT 25 NNE CPW 20 NE MYP 35 SE CCU
25 NW AFF 15 E FCS.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
35 SSW OTM 30 WSW EOK 45 SW UIN 30 SSW SZL 15 NW BVO 25 NE HBR
40 SSE CDS 30 N SNK 55 ENE HOB 40 SSE CVS 20 ENE TCC 25 WNW AMA
10 NE PPA 30 NW AVK 15 S MHK 35 SW LWD 35 SSW OTM.


...SOUTHERN HIGH PLAINS / SOUTHERN AND CENTRAL PLAINS / LOWER
MIDWEST...

21Z UPDATE...WEATHER FEATURES STILL APPEARED ON TRACK TO PRODUCE
AREA OF ORGANIZED HEAVY PRECIPITATION AND OTHER LOCALLY HEAVY
DOWNPOURS ALONG A FRONTAL ZONE. CONVERGENCE ON THE LARGE SCALE
WILL REMAIN RATHER BROAD AS 850 MB FLOW IS FORECAST TO VEER
PARALLEL TO THE FRONTAL ZONE FROM NORTH TX TO THE LOWER GREAT
LAKES. THIS MAY ESPECIALLY HINDER CONVECTIVE ORGANIZATION OVER
OKLAHOMA WHERE MID LEVEL SUPPORT IS LACKING UNTIL A WAVE ARRIVES
FROM THE WEST LATER TONIGHT. STILL...FRONTAL FORCING SHOULD BE
SUFFICIENT TO INITIATE CONVECTION...WHICH SHOULD THEN MAKE
EFFICIENT USE OF THE STRONG INSTABILITY IN PLACE...TO PROMOTE
WIDESPREAD RAINFALL...SOME VERY HEAVY. THE LOW LEVEL JET WOULD
MORE FAVORABLY INTERCEPT ONGOING CONVECTION ACROSS WEST AND
NORTHWEST TEXAS IF OUTFLOWS CAN PUSH INTO THAT REGION AFTER
INITIAL DEVELOPMENT FARTHER NORTH AND WEST. A STRONG SIGNAL FOR
THIS OCCURRENCE EXISTS IN THE 12Z WRF-ARW...NMM...AND NSSL WRF.
WPC EXPANDED THE SLIGHT AND MODERATE RISK CONTOURS IN THAT REGION.
WE ALSO EXTENDED THE SLIGHT AND MODERATE RISK CONTOURS DEEPER INTO
MISSOURI AND ILLINOIS...EVEN CLIPPING SOUTHERN WISCONSIN WITH THE
SLIGHT RISK CONTOUR. THE INSTABILITY AXIS WILL BE MORE NARROW AND
SHORTER LIVED WITH EASTWARD EXTENT...BUT RAIN RATES SHOULD BE
INTENSE WITH ANOMALOUS MOISTURE AND MODERATE DEEP LAYER FORCING.
THIS REGION HAS ALSO BEEN VERY WET OVER THE PAST MONTH...WHICH
COULD CONTRIBUTE TO A GREATER PERCENTAGE OF SURFACE RUNOFF.

IN THE NEAR TERM THIS EVENING...THE MOST CONCENTRATED RISK OF
EXCESSIVE RAINFALL APPEARS TO BE FROM THE IA/MO BORDER INTO
NORTHERN MO AND EASTERN KS. SEE MESOSCALE PRECIPITATION DISCUSSION
NUMBER 314 FOR FULL DETAILS.

PREVIOUS DISCUSSION...POOLING OF PWS TO NEAR OR JUST ABOVE 2
INCHES NEAR THE FRONTAL BOUNDARY...ALONG WITH SHORT TERM CELL
TRAINING...SUGGESTS HEAVY TO VERY HEAVY RAINFALL AMOUNTS...WITH
FLOODING CONCERNS INCREASING ON MONDAY NIGHT OVER PARTS OF THE
CENTRAL AND SOUTHERN PLAINS. AREAL AVERAGE 1-3 INCH RAINFALL
TOTALS EXPECTED FROM EASTERN KS INTO WESTERN OK AND THE TX
PANHANDLE...WITH ISOLATED HEAVIER AMOUNTS OF 3-5 INCHES POSSIBLE.

WEAK SHORTWAVES RIDING UP THE WESTERN SIDE OF THE RIDGE WILL SPUR
AN UPPER DIVERGENCE MAXIMA CROSSING SOUTHERN CO AND NORTHEAST NM.
MONSOONAL MOISTURE HAD WORKED ITS WAY INTO THE PARTS OF THE
REGION. GFS FCST PRECIPITABLE WATER VALUES ARE NEAR 2 STD
DEVIATIONS ABOVE NORMAL THIS EVENING IN EASTERN NM.  THESE
PARAMETERS...ALONG WITH HEATING AND LOW LEVEL UPSLOPE FLOW SHOULD
SUPPORT ANOTHER PERIOD OF INCREASED CONVECTION THRU PARTS OF CO
AND NM.  SOME LOCALLY HEAVY RAINS CAN BE EXPECTED...AND MESOSCALE
PRECIPITATION DISCUSSION NUMBER 313 IS IN EFFECT UNTIL NEAR 00Z.


...SOUTHWEST WYOMING / EASTERN IDAHO / NORTHERN UTAH...

A MONSOON STYLE RIDGE AXIS WAS IN PLACE OVER THE SOUTHWEST...AND
PW VALUES APPROACHING OR SLIGHTLY EXCEEDING 1 INCH EXTENDED AS FAR
NORTH AS WY/ID/UT. SURFACE DEWPOINTS WERE NOT ESPECIALLY
ANOMALOUS...AND ENHANCED FLOW AROUND A MID LEVEL LOW ENTERING
CALIFORNIA HAD NOT YET EXPANDED INTO THE INTERMOUNTAIN REGION.
THIS SUGGESTS THAT MOST AREAS IN THE WEST WILL SEE AN AVERAGE
MONSOON STYLE AFTERNOON AND EVENING WITH THE FLASH FLOOD THREAT
CONFINED TO SHORT DURATION AND LOCALIZED CELLS. THE ONE EXCEPTION
APPEARED TO BE NEAR THE TOP OF THE RIDGE WHERE A SMALL CYCLONIC
CIRCULATION WAS MOVING EASTWARD ACROSS THE BORDER AREAS OF
WY/ID/UT. ENHANCED LIFT AND WIND FIELDS NEAR THIS FEATURE RAISES
THE POSSIBILITY OF GREATER CONVECTIVE COVERAGE AND TRAINING. THERE
IS A HIGH RESOLUTION MODEL CONSENSUS FOR LOCALLY HEAVIER
RAINFALL...ESPECIALLY IN SOUTHWEST WYOMING THROUGH 06Z. RAIN RATES
COULD EXCEED 1 INCH PER HOUR WHEREVER TRAINING OCCURS...AND SOME
OF THE MORE RELIABLE MODELS INDICATE SPOT TOTALS ABOVE 1.5 INCHES.

BURKE/PETERSEN
$$





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