Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Text Only | 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 070101
QPFERD

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

...VALID 01Z TUE JUL 07 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
10 ENE GNT 30 N CPW 25 SE LXV 35 WNW AFF 20 WNW FCS 25 NNE VTP
30 SSE RTN 40 WSW DHT 25 ENE BGD 10 SE LWC 10 S CWI 15 NE UGN
SBN 10 NNW DNV 30 SE VIH 25 N TQH 20 SW OKM 25 NNE RPH 15 SE SWW
20 SSW BPG 25 SSE HOB 25 ESE ROW 15 NW ATS 40 WSW ATS 25 SE ALM
15 SW HMN 20 ENE TCS 10 ENE GNT.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 ESE BVO 10 WNW SPS 30 NNE SWW 55 ENE HOB CVN AMA 30 N WDG
25 N CNU 25 SSE LXT SZL 35 S SZL 20 ESE BVO.


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

01Z UPDATE...RELATIVELY SHORT DURATION BUT INTENSE RAIN RATES ARE
EXPECTED TO CONTINUE ALONG THE LENGTH OF A SURFACE FRONT AND
ASSOCIATED CONVECTIVE OUTFLOWS SAGGING INTO THE SOUTHERN
PLAINS...THE OZARKS...AND AREAS BORDERING THE SOUTHERN END OF LAKE
MICHIGAN. CONCERN FOR LONGER DURATION TRAINING IS MOST PRONOUNCED
OVER WESTERN NORTH TEXAS. WPC CONTINUED TO PUSH THE BACK EDGE OF
THE SLIGHT AND MODERATE RISK AREAS SOUTHWARD...BUT IN THE 01Z
UPDATE DID NOT EXPAND THE SOUTHERN EDGE. ANY CONVECTION PUSHING
INTO SOUTHEAST OK OR CENTRAL AR BY MORNING WOULD LIKELY BECOME
OUTFLOW DOMINATED.

PREVIOUS DISCUSSION...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 HAD BEEN SUFFICIENT TO INITIATE
CONVECTION...AND THAT CONVECTION WILL CONTINUE TO MAKE EFFICIENT
USE OF THE STRONG INSTABILITY IN PLACE...TO PROMOTE WIDESPREAD
RAINFALL...SOME VERY HEAVY. THE LOW LEVEL JET WILL MORE FAVORABLY
INTERCEPT ONGOING CONVECTION ACROSS WEST AND NORTHWEST TEXAS. A
STRONG SIGNAL FOR HEAVY RAIN WAS SEEN IN THIS REGION IN THE 21-23Z
RUNS OF THE HRRR OUT THROUGH NEAR 12Z TUESDAY. THE 12Z
WRF-ARW...NMM...AND NSSL WRF HAD FIRST POINTED AT THIS SCENARIO.
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. MUCH OF THE REGION FROM THE
SOUTHERN PLAINS TO MIDWEST HAS BEEN VERY WET OR HISTORICALLY WEST
IN RECENT MONTHS...WHICH COULD CONTRIBUTE TO A GREATER PERCENTAGE
OF SURFACE RUNOFF.

FARTHER WEST...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...AND LOW LEVEL CONVERGENCE WILL INCREASE
WESTWARD THROUGH THE MOUNTAINS AS SURFACE HIGH PRESSURE BUILDS
ALONG THE HIGH PLAINS. THE LATE AFTERNOON HRRR RUNS MAINTAINED A
SIGNAL FOR LOCALLY HEAVY RAIN LASTING INTO TONIGHT OVER CO/NM.


...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
$$




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