Quantitative Precipitation Forecast
Issued by NWS

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FOUS30 KWBC 310758
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
357 AM EDT FRI JUL 31 2015

...VALID 12Z FRI JUL 31 2015 - 12Z SAT AUG 01 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
60 SSE SJN 10 NW GNT 25 ESE E33 40 NW CAO 20 NW EHA 40 NE PYX
10 SSE JWG 20 W PVJ 15 SW LAW LTS 25 NNW PVW 10 SSE TCC CQC
65 NNE TCS 25 NNE SVC 60 SSE SJN.



...SOUTHWEST/SOUTHERN PLAINS...

MONSOONAL MOISTURE CONTINUES TO POUR INTO THE SOUTHWEST
STATES...AND SOME OF THE DEEP MOISTURE IS BEING DIVERTED INTO THE
SOUTHERN PLAINS ALONG AN FRONTAL BOUNDARY. THE DEEP
MOISTURE...COMBINED WITH MARGINAL TO MODERATE INSTABILITY...COULD
RESULT IN ORGANIZED CONVECTION WHICH PRODUCES HEAVY TO EXCESSIVE
RAINFALL ACROSS PORTIONS OF THE REGION DURING DAY 1.

CONVECTION CONTINUES ACROSS EAST CENTRAL NM EARLY THIS
MORNING...AS DEEP MOISTURE (WITH PRECIPITABLE WATER VALUES NEAR
1.25 INCHES) FEEDS THE ACTIVITY. THERE IS A MULTI HIGH RESOLUTION
MODEL SIGNATURE THAT AN MCV WILL BE EJECTED FROM THIS
ACTIVITY...WHICH CROSSES NORTHEAST NM ACROSS NORTH TX INTO THE
WESTERN OK PANHANDLE. THE MCV ENCOUNTERS DEEP MOISTURE AND
MODERATE INSTABILITY ALONG EN ELEVATED BOUNDARY EXTENDING ACROSS
NORTHEAST NM AND NORTH TX...WHERE MODEL SOUNDINGS SHOWED MODERATE
TO LOCALLY STRONG INSTABILITY DEVELOPING AFTER 31/18Z.

THE LOW LEVEL FLOW INCREASES ACROSS WEST TX INTO WESTERN OK AND
WESTERN KS AFTER 01/00Z...THOUGH THERE IS SOME SPREAD CONCERNING
JUST HOW STRONG IT GETS. ASSUMING A 20 KNOT LOW LEVEL INFLOW INTO
NORTH TX...A SMALL MCS COULD DEVELOP AFTER 01/06Z THERE...AND
CONTINUE EAST SOUTHEAST ALONG THE DIFLUENT THICKNESS PATTERN INTO
SOUTH CENTRAL OK BEFORE 01/12Z. THE MOISTURE IS DEEP ENOUGH FOR
HIGH RAINFALL RATES WITH THE MCS...SO AN AREA OF 1.50 TO 2.00
INCHES OF QPF WAS PLACED OVER NORTH TX AND NEARBY WESTERN OK.
WHILE THE QPF VALUES ARE BELOW THE THREE HOUR FLASH FLOOD GUIDANCE
VALUES...THE POTENTIAL FOR HIGH RAINFALL RATES SUGGESTS THE
POTENTIAL FOR FLASH FLOODING. ACCORDINGLY...A SLIGHT RISK WAS
EXTENDED FROM NORTHEAST NM (WITH THE MCV) INTO NORTH TX AND A
PORTION OF WESTERN OK.

FURTHER WEST...THE MONSOONAL FLOW CONTINUES ACROSS AZ/WESTERN NM.
THERE IS A MULTI MODEL SIGNAL THAT A SHORT WAVE IN THE MID LEVEL
SOUTHERLY FLOW UNDER THE RIDGE COULD CROSS AZ DURING THE SECOND
HALF OF THE PERIOD. THAT COULD ENHANCE LIFT ACROSS EASTERN
AZ/WESTERN NM...ALLOWING CONVECTION TO FORM OUTSIDE OF THE
TERRAIN. THE HIGH MOISTURE CONTENT AIR (WITH PRECIPITABLE WATER
VALUES TOPPING OUT NEAR 1.75 INCHES IN SOUTHWEST AZ) COULD ALLOW
FOR LOCALLY HEAVY RAINFALL WITH THE CONVECTION. HOWEVER...AT THIS
POINT...IT IS UNCLEAR JUST HOW WIDESPREAD THE HEAVIER RAINFALL
WILL BE...SO FOR NOW NO SLIGHT RISK AREA WAS ASSIGNED.

HAYES
$$




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