Quantitative Precipitation Forecast
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000
FOUS30 KWBC 080052
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
852 PM EDT TUE JUL 07 2015

...VALID 01Z WED JUL 08 2015 - 12Z WED JUL 08 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
45 SE MLC 10 W GVT 10 NNW GTU 10 E ERV 45 WSW DRT 55 S 6R6
30 WSW 6R6 35 N 6R6 10 W SWW 30 WNW LTS 20 E WLD 15 SSW SZL
45 SW PPQ 10 WSW BMG LUK 35 SSE ILN 45 NW HTS 20 NW HTS
10 SE HTS 40 WNW I16 35 NNE LNP 10 NNW LNP 25 NE 1A6 20 WNW 1A6
15 E GLW 20 W HOP 30 NNW LRF 15 SSE RKR 45 SE MLC.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
ARG 35 ESE FSM 20 E DUA 15 SSE GYI 25 N 05F 20 WNW 6R9
25 NW JCT 20 NNE E29 15 NW SJT 45 NNE ABI 20 NNW SPS 10 E FSI
15 W TUL 20 SE SGF 15 NW CGI 25 ESE HSB 15 SSW EHR 30 ESE PAH
ARG.

HIGH RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 NNW FSM JSV 20 NNW AQR 10 E PVJ 25 NNE PVJ 10 SE CQB
10 SSW GMJ 35 N BPK 10 SE UNO 25 S UNO 10 SSE FLP 25 SE FYV
15 NNW FSM.


EVENING UPDATE...

RADAR TRENDS WERE NOT TERRIBLY IMPRESSIVE OVER PARTS OF THE ERN OK
INTO NORTHWEST AR/SOUTHERN MO AS OF EARLY EVENING...PARTLY IN
RESPONSE TO OUTFLOW BEING FAIRLY FAR SOUTH.  WE MAINTAINED THE
HIGH RISK WHERE IT WAS INITIALLY PLACED SINCE THERE WAS A
CONSISTENT SIGNAL FOR SOUTHERLY FLOW TO STRENGTHEN LATER
TONIGHT...EVEN IF THE MODEL PRODUCED RAFL WAS NOT TERRIBLY
CONSISTENT BETWEEN THE VARIOUS MODELS.  00Z RAOBS SHOWED SOUTH TO
SOUTHWEST FLOW ALOFT AT 25 TO 30 KTS WAS ABLE TO CONTINUE FEEDING
AN AIRMASS WITH 15 DEG C DEWPOINTS AT 850 MB INTO THE REGION OF A
SOUTHWEST TO NORTHEAST SURFACE BOUNDARY...AND THERE WAS AN AXIS OF
2 TO 2.25 INCH PRECIPITABLE WATER VALUES EXTENDING FROM E TX INTO
SOUTHWEST MO.  WITH THE STRENGTHENING LOW LEVEL FLOW...SUSPECT
THAT HEFTY RAINFALL AMOUNTS ARE STILL POSSIBLE EVEN IF THE
CONVECTION IS ELEVATED.  THERE HAS ALREADY BEEN SOME TRAINING
ALONG PARALLELING THE SURFACE BOUNDARY...AND THERE IS THE
POTENTIAL FOR THE TRAINING TO CONTINUE EVEN AS THE APPROACH OF AN
MCV FROM NORTHEAST TX RE-ORIENTS THE PCPN BANDS.  STILL THINK
AREAL AVERAGE AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE ACROSS THIS
AREA WITH HEAVIER TOTALS IN EXCESS OF 5 INCHES BEING POSSIBLE
WHERE PERSISTENT TRAINING OCCURS.

OUT ACROSS NORTHEAST CA INTO THE GREAT BASIN AND THE ROCKIES...00Z
RAOBS SHOW AN UNUSUALLY MOIST AIRMASS WAS IN PLACE AND THAT WITH
PRONOUNCED UPPER LEVEL DIFLUENCE WHICH WAS IN LINE WITH THE
EARLIER FORECAST.  THINK THAT CONVECTION WILL SETTLE DOWN A BIT
LATER TONIGHT BUT THEN REDEVELOP DURING THE DAY ON WEDNESDAY GIVEN
RELATIVELY FEW CHANGES IN THE BIG PICTURE.

BANN

PREVIOUS DISCUSSION BELOW...


CENTRAL TO NORTH-CENTRAL TX---CENTRAL TO EASTERN OK--NORTHWEST
AR---SOUTHERN MO---KY---FAR SOUTHERN IL AND FAR SOUTHERN IN

CHANGES TO THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK WERE
TO EXTEND THE EASTERN EXTENT OF THE SLIGHT RISK AREA INTO EASTERN
KY TO COVER THE RAINFALL POTENTIAL THROUGH 1200 UTC.  A HIGH RISK
AREA WAS INTRODUCED FROM EASTERN OK INTO NORTHWEST AR AND FAR
SOUTHWEST MO WHERE TRAINING OF CELLS IS LIKELY THIS
PERIOD---INITIALLY IN WEST SOUTHWEST TO EAST NORTHEASTERLY
DIRECTION AND THEN LATER IN A SOUTH SOUTHWESTERLY TO NORTH
NORTHEASTERLY DIRECTION.  WIDESPREAD HEAVY TO EXCESSIVE RAINFALL
AMOUNTS LIKELY THIS PERIOD FROM NORTH CENTRAL TX--ACROSS CENTRAL
TO EASTERN OK---CENTRAL TO SOUTHERN MO---AND THEN EASTWARD ALONG
AND SOUTH OF THE OH RIVER ACROSS MOST OF KY INTO SOUTHWEST WV.  A
STATIONARY FRONTAL BOUNDARY ACROSS THESE REGIONS WILL BE THE FOCUS
FOR ACTIVE CONVECTION THIS PERIOD IN AN AXIS OF MUCH ABOVE AVERAGE
PW VALUES STRETCHING ALONG THE BOUNDARY.  TRAINING OF CELLS IS A
SIGNIFICANT RISK THIS PERIOD ALONG THE FRONTAL BOUNDARY.  THIS
TRAINING WILL BE IN A WEST TO EASTERLY DIRECTION FROM EASTERN
OK---ACROSS NORTHERN AR---SOUTHERN MO AND ALONG AND SOUTH OF THE
OH RIVER WHERE LOW LEVEL WEST SOUTHWESTERLY FLOW WILL PERSIST FOR
THE REMAINDER OF THIS FORECAST PERIOD.  FARTHER TO THE WEST---THE
LOW LEVEL FLOW IS EXPECTED TO BE MORE SOUTH SOUTHWESTERLY FROM
NORTH CENTRAL TX INTO CENTRAL TO EASTERN OK AHEAD OF THE MCV
MOVING EASTWARD ACROSS NORTH TX---WITH TRAINING OF CELLS IN A
SOUTH SOUTHWEST TO NORTH NORTHEASTERLY DIRECTION LIKELY
TONIGHT---CONTINUING INTO EARLY WEDNESDAY.  THERE IS A STRONG
MODEL SIGNAL FOR VERY HEAVY TO EXCESSIVE RAINFALL AMOUNTS ACROSS
THESE AREAS--LEADING TO ABOVE AVERAGE CONFIDENCE WITH THE HEAVY
RAIN FORECAST THIS PERIOD.  AREAL AVERAGE 2-4" AMOUNTS POSSIBLE
ACROSS THESE AREAS---WITH HEAVIER TOTALS IN EXCESS OF 5" WHERE THE
MOST PERSISTENT TRAINING OCCURS.

NORTHEAST CALIFORNIA---GREAT BASIN INTO THE CENTRAL ROCKIES

NO CHANGES TO THINKING ACROSS NORTHEAST CALIFORNIA INTO THE GREAT
BASIN AND CENTRAL ROCKIES REGION.  OVERALL---THERE IS GOOD MODEL
AGREEMENT WITH THE SLOW EASTWARD PUSH OF THE CLOSED LOW OFF THE
NORTHERN CALIFORNIA COAST AND TOWARD THE CENTRAL CALIFORNIA COAST
AND A LEADING SLOW MOVING VORT FROM THE GREAT BASIN INTO THE
CENTRAL ROCKIES.  PW VALUES EXPECTED TO REMAIN MUCH ABOVE AVERAGE
TO THE EAST NORTHEAST OF BOTH THE CALIFORNIA CLOSED LOW AND GREAT
BASIN VORT FROM NORTHERN CALIFORNIA--INTO THE GREAT BASIN AND INTO
THE CENTRAL ROCKIES.  WITH UPPER DIFFLUENCE EXPECTED TO REMAIN
WELL DEFINED AHEAD OF THESE FEATURES--WIDESPREAD SCATTERED
CONVECTION LIKELY AGAIN FROM NORTHEAST CALIFORNIA---ACROSS THE
GREAT BASIN AND INTO THE CENTRAL ROCKIES.  ISOLATED HEAVY TO
EXCESSIVE RAINFALL AMOUNTS POSSIBLE IN THIS HIGH PW AXIS WITH
POTENTIAL FOR FAIRLY SLOW MOVING CELLS.


ORAVEC


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