Quantitative Precipitation Forecast
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FOUS30 KWBC 282259
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
658 PM EDT SUN SEP 28 2014

...VALID 00Z MON SEP 29 2014 - 00Z TUE SEP 30 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 SW GNV 45 SW CTY 40 S TLH 25 SSW AAF 30 SSW PAM 30 N ECP
15 SSE LSF 15 SSW HQU 15 N OGB 45 NNE CHS 25 ENE SSI 10 SW GNV.


SOUTHEAST
~~~~~~~~~
A DIFFUSE UPPER LEVEL TROUGH WILL PUSH SLOWLY EAST OF THE
MISSISSIPPI DURING THE PERIOD, PROVIDING DIFFLUENCE ALOFT AND
CAUSING A POCKET ENHANCED LOW-MID LEVEL FRONTOGENESIS NEAR A
STATIONARY FRONT CLOSE TO THE SOUTHEAST COAST AND SOUTHERN GA. IN
TERMS OF THE QPF DETAILS...MODEL DIFFERENCES REMAIN...WITH
SIGNIFICANT SPREAD IN TERMS OF HOW FAR NORTH AND NORTHWEST
MEASURABLE RAINFALL WILL GET THROUGH 00Z TUE.  SO FAR, THE MORE
NORTH AND NORTHWESTERLY GUIDANCE HAS NOT BEEN VERIFYING.  THE 00Z
WPC QPF TRENDED BACK TOWARDS A MORE COASTAL SOLUTION AS THE 12Z
GFS/18Z NAM/RECENT RAP RUNS SUGGEST THAT THE 850 HPA REFLECTION OF
THE FRONTAL ZONE MAKES VERY LITTLE INROADS INTO GEORGIA OVERNIGHT.
 THE 12Z SSEO MEAN IS ALONG THE LINES OF THE 00Z WPC QPF.  SOME
CIN IS EXPECTED ALONG THE SURFACE BOUNDARY WHICH SHOULD CAUSE
CONVECTION OVERNIGHT TO BECOME MORE ELEVATED IN THE 03-15Z TIME
FRAME.  MUCAPES OF 1000+ J/KG ACROSS NORTHERN FL AND SOUTHEAST GA
WILL BE SUFFICIENT IN GENERATING AREAS OF HEAVY RAINFALL
(POTENTIALLY EXCESSIVE RAINFALL RATES) NEAR THE FL/GA BORDER GIVEN
THE THERMODYNAMIC SETUP WITH PRECIPITABLE WATER VALUES ~2.25" AND
WET BULB ZERO LEVELS ABOVE 14000 FT (FAVORING OPTIMAL
PRECIPITATION EFFICIENCY AND WARM RAIN PROCESSES).  THE LOW-LEVEL
INFLOW WILL REMAIN FAIRLY WEAK (~15-20 KTS), SO DO NOT ANTICIPATE
THE DEVELOPMENT OF A CONVECTIVE COMPLEX ACROSS THE REGION, THOUGH
TRAINING QUASI-LINEAR BANDS OF CONVECTION ARE POSSIBLE.  ACROSS
SOUTHERN GA, THE HIGHER RESOLUTION GUIDANCE GENERALLY ADVERTISES
LOCALIZED AMOUNTS OF 6-9" THROUGH MONDAY EVENING (WITH THE
HIGH-BIASED 18Z NAM CONEST SHOWING MAXIMA NEAR 12").  A SLIGHT
RISK OF EXCESSIVE RAINFALL WAS INDICATED IN THIS REGION DUE TO THE
LINGERING UNCERTAINTY IN PRECIPITATION PLACEMENT, THOUGH IT HAS
BEEN SHIFTED EASTWARD PER THE 00Z WPC QPF.

SOUTHEAST WYOMING
~~~~~~~~~~~~~~~~~
THE ANOMALOUS DEEP UPPER TROUGH/CLOSED LOW ACROSS THE LOWER GREAT
BASIN WILL SHIFT ONLY SLIGHTLY EASTWARD TODAY...THEREBY
MAINTAINING FAVORABLE DYNAMIC SUPPORT (UPPER
DIFFLUENCE/DIVERGENCE) VIA THE WARM CONVEYOR BELT (WCB) ALONG WITH
THE MOIST...S/SE LOW-LEVEL FLOW AND UPSLOPE ENHANCEMENT ACROSS THE
CENTRAL ROCKIES.  RECENT RAP RUNS ADVERTISE SOME INSTABILITY
(MUCAPES ~500 J/KG) WITHIN A REGION OF FAVORABLE MOISTURE PROFILES
(PWS 2-3 STANDARD DEVIATIONS ABOVE THE NORM FOR LATE SEPTEMBER)
WHICH SUPPORTS THE POTENTIAL OF ISOLATED EXCESSIVE SHORT TERM
RAINFALL RATES AND THUS RUNOFF ISSUES.

ROTH/HURLEY
$$




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