Quantitative Precipitation Forecast
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FOUS30 KWBC 301819
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
218 PM EDT WED JUL 30 2014

...VALID 18Z WED JUL 30 2014 - 00Z FRI AUG 01 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 SW PTT 10 NE CFV 10 SSE FLP 20 NNE SGT 10 SSE PBF 30 S M89
15 NW DUA 15 NE HBR 20 WNW CSM 25 E HHF 15 WNW GAG 40 NNW WWR
15 SW PTT.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
30 S MYP 10 WNW MYP 15 NNE ASE 20 W 20V 45 N 20V 25 WSW PUM
10 SSE PUM 10 WNW FNL 15 N BJC 10 N AFF 20 WSW PUB 15 ENE VTP
25 WNW RTN 25 W RTN 20 NE SKX 25 S ALS 10 SSW ALS 30 S MYP.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
30 ESE SNL 20 E SNL 20 ENE SNL 10 SE CQB 15 N CQB 30 ENE SWO
20 NW TUL 15 NNE TUL 15 NNW TQH 15 ENE TQH 35 WNW RUE 15 SSE RUE
15 NW HOT 15 S MWT 30 NNE DEQ 35 WSW RKR 30 NW MLC 30 ESE SNL.


THE AIRMASS ACROSS CENTRAL AND WESTERN CO IS STARTING TO
RECOVER...AS MLCAPES INCREASE IN THE PRESENCE OF WEAK UPSLOPE. THE
REJUVENATION OF THE AIRMASS COULD SUPPORT CONVECTION THIS
AFTERNOON INTO THE EVENING HOURS...AND THE WATER VAPOR LOOP SHOWS
AN APPROACHING WEAK SHORT WAVE. THE COMBINATION OF SYNOPTIC SCALE
ASCENT...MARGINAL INSTABILITY AND PRECIPITABLE
WATER VALUES AROUND 1.10 INCHES COULD RESULT IN LOCAL 1 INCH QPF
AMOUNTS...MAINLY BEFORE 31/03Z. ONE AND THE HOUR FLASH FLOOD
GUIDANCE VALUES HERE ARE AS LOW AS 0.75 INCHES...DUE TO EARLIER
HEAVY RAINFALL...SO A SLIGHT RISK WAS RETAINED FOR THE ROCKIES IN
CO AND FAR NORTHERN NM. AFTER 03Z...HIGH RESOLUTION MODEL OUTPUT
SUGGESTS THAT THE THREAT DIMINISHES DUE TO LOSS OF MOISTURE AND
INSTABILITY.

A PRECIPITABLE WATER PLUME OF NEAR 1.30 INCHES STILL STRETCHES
FROM NORTHWEST UT INTO SOUTHEAST ID AND WESTERNMOST WY...IN THE
PRESENCE OF MLCAPES IN THE NEIGHBORHOOD OF 1000 J/KG. THE SHORT
WAVE MOVING ACROSS SOUTHWEST WY COULD PROVIDE SYNOPTIC SCALE LIFT
ACROSS THIS REGION DURING THE AFTERNOON AND EVENING
HOURS...SPARKING SCATTERED CONVECTION. THE ONE HOUR FLASH FLOOD
GUIDANCE VALUES ARE CLOSE TO AN INCH...ESPECIALLY IN THE TERRAIN
OF WESTERN WY AND NORTHERN UT. WHILE MOISTURE REMAINS IN
PLACE...THE ACTIVITY SHOULD REMAIN WIDELY SCATTERED AND TIED TO
THE TERRAIN. BECAUSE OF THE LACK OF COVERAGE...THIS AREA WAS
REMOVED FROM THE SLIGHT RISK AND PLACED IN A SEE TEXT...MAINLY FOR
ACTIVITY THROUGH 31/03Z.

THE ACTIVITY DRIVEN BY THE MCV OVER NORTH CENTRAL OK HAS
DIMINISHED IN COVERAGE AND INTENSITY AS THE AIRMASS HAS YET TO
RECOVER FROM A CONVECTIVE STANDPOINT...EVEN IN THE PRESENCE OF
PRECIPITABLE WATER VALUES NEAR 2.00 INCHES. THE MCV SHOULD REMAIN
THE DRIVING FORCE WITH RESPECT TO LIFT...AIDED BY WEAK SHORT WAVES
DROPPING OUT OF THE ROCKIES INTO THE SOUTHERN PLAINS AFTER 31/00Z.
THERE IS A MULTI MODEL SIGNAL THAT THE LOW LEVEL SOUTHERLY FLOW
BECOMES REINVIGORATED AFTER 31/0Z AS A 25 TO 35 KNOT LOW LEVEL JET
POINTS TOWARD EAST CENTRAL OK AND WEST CENTRAL AR. PRECIPITABLE
WATER VALUES REMAINS BETWEEN 1.75 AND 2.00 INCHES ON THE NOSE OF
THE LOW LEVEL JET...AND THE NAM SIMULATED IMAGERY SHOWS ANOTHER
MCS DEVELOPING ACROSS EAST CENTRAL OK AFTER 31/03Z. IT REACHES
PEAK INTENSITY NEAR 31/09Z IN EASTERN OK AND STARTS TO DIMINISH
WITH THE LOSS OF THE LOW LEVEL JET BEFORE 31/15Z.

THERE IS A STRONG SIGNAL FOR A SWATH OF 2 TO 4 INCHES OF QPF IN
THIS AREA...WITH A PEAK NEAR 3.50 INCHES ACROSS WEST
CENTRAL AR. THERE WERE ALSO A NUMBER OF 12Z GEFS MEMBERS SHOWING
THE POTENTIAL FOR 4+ INCHES IN EAST CENTRAL OK AND WEST CENTRAL
AR...SO A MODERATE RISK WAS RETAINED HERE. IT WAS SURROUNDED BY A
SLIGHT RISK FOR THE REMAINDER OF EASTERN OK AND WESTERN AR.


HAYES



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