Areal Flood Warning 2, NWS Atlanta, GA

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
956 PM EST WED MAR 10 2010

.UPDATE...
LATEST SURFACE ANALYSIS SHOWS A WEDGE OF COOL...STABLE AIR NOSING
DOWN FROM THE NE...AND HELPING TO HINDER WIDESPREAD THUNDERSTORM
DEVELOPMENT THIS EVENING. ALTHOUGH THIS TREND SHOULD CONTINUE
OVERNIGHT... A SERIES OF UPPER DISTURBANCES AND MODERATE MID LEVEL
LAPSE RATES WILL CONTINUE TO SUPPORT THE OCCASIONAL EMBEDDED
THUNDERSTORM OVERNIGHT. THE GREATER THUNDERSTORM THREAT OVERNIGHT
WILL BE MAINLY OVER THE WEST CENTRAL AND SW PORTIONS OF THE FORECAST
AREA...GENERALLY ALONG AND WEST OF A NEWNAN TO TALBOTTON TO
AMERICUS LINE...WHERE A STRAY STRONG THUNDERSTORM MOVING OUT OF
ALABAMA...WHERE INSTABILITIES ARE GREATER...COULD POTENTIALLY DUMP
HAIL AND LOCALLY HEAVY RAIN. THE FREEZING LEVEL IS DOWN AROUND 9000
FT...SO CANNOT RULE OUT LARGE HAIL IF THE STORM CAN GENERATE A
STRONG UPDRAFT. A BIT CONCERNED ABOUT THE WIDESPREAD THUNDERSTORM
DEVELOPMENT OVER SOUTH CENTRAL AL THIS EVENING...AND A FEW STRONG
STORMS FROM THIS MAY PUSH INTO WEST CENTRAL GA LATER TONIGHT...BUT
EXPECT THE COOL/STABLE WEDGE TO HELP WEAKEN STORMS AS THEY PUSH INTO
GA. STILL SOME CONCERN ABOUT HEAVY RAIN POTENTIAL... SO WILL LEAVE
THE FLOOD WATCH IN PLACE... BUT SUSPECT THE WATCH MAY HAVE TO BE
EXTENDED THRU THU MORNING AND POSSIBLY ADJUSTED A BIT SOUTHWARD WITH
THE 4 AM FORECAST PACKAGE AS NEW DEVELOPMENT PUSHES INTO GA IN THE
MORNING AND POSSIBLY CONTINUES INTO EARLY AFTERNOON. HAVE INCREASED
POPS TO 100% AFTER MIDNIGHT FOR MOST AREAS... BUT OTHERWISE THE
FORECAST STILL LOOKS ON TRACK AT THIS TIME.  /39

-----------------------PREVIOUS DISCUSSION--------------------
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS AFFECTING MUCH OF
THE COUNTY WARNING AREA THIS AFTERNOON AS GULF MOISTURE INCREASES
OVER THE AREA...AHEAD OF A STORM SYSTEM MEANDERING ACROSS THE
CENTRAL U.S. MODELS MAINTAIN A SERIES OF UPPER LEVEL DISTURBANCES
MOVING ACROSS THE SOUTHEAST U.S. WHICH WILL AID IN THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE SHORT TERM
PERIOD. FIRST IMPULSE PROGGD TO LIFT INTO THE CAROLINAS
TONIGHT...WITH ANOTHER IMPULSE LIFTING NORTHEAST FROM THE GULF
COAST LATE TONIGHT/EARLY THURSDAY. MAY GET INTO A LULL THURSDAY
AFTERNOON/EVENING BETWEEN IMPULSES...BUT YET ANOTHER DISTURBANCE
ALONG WITH APPROACHING FRONT PROGGD TO AFFECT THE AREA FRIDAY.
WILL FOLLOW PREVIOUS FORECAST TREND WITH LIKELY TO CATEGORICAL
POPS FOR MUCH OF THE COUNTY WARNING AREA THROUGH THE PERIOD. WILL
BEGIN TO TAPER POPS OFF FROM THE WEST FRIDAY NIGHT AS THE FRONT
PUSHES THROUGH THE STATE. SO FAR SPC NOT TARGETING ANY AREA FOR
RISK OF SEVERE...BUT MODELS ARE SHOWING FAIRLY DECENT CAPE OVER
PORTIONS OF CENTRAL GEORGIA THURSDAY AND OVER MUCH OF THE AREA
FRIDAY WITH FRONT PUSHING THROUGH. TEMPERATURES CONTINUE TO BE A
CRAP SHOOT...WITH SOME MOS LOWS WARMER THAN CURRENT TEMPS. WILL
BACK OFF A TAD FROM MOS LOWS...BUT DO NOT WANT TO GO TOO FAR BELOW
GUIDANCE WITH WARM FRONT IN THE AREA. WILL GENERALLY USE A MAV/MET
BLEND AS A GENERAL RULE.

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
EXTENDED PROGS SIMILAR WITH UPPER LOW DRIFTING SOUTHEAST FROM THE
GREAT LAKE REGION OVER THE WEEKEND THEN MOVING OFF THE MID
ATLANTIC COAST BY TUESDAY. COMPLICATED SURFACE PATTERN WITH SERIES
OF SURFACE LOWS MOVING ACROSS THE OH/TN VALLEY DURING THE
PERIOD...WITH FIRST LOW PRESSURE SYSTEM CONTINUING TO PUSH OFF THE
SOUTHEAST U.S. COAST SATURDAY AS ANOTHER WEAK LOW PRESSURE SYSTEM
PULLS A WEAK FRONTAL BOUNDARY ACROSS THE STATE SATURDAY
NIGHT/SUNDAY. MODELS KEEP THE BULK OF MOISTURE ASSOCIATED WITH
THIS FEATURE ACROSS NORTH GEORGIA. MODELS MAINTAIN SOME DEEPER
MOISTURE ACROSS NORTH GEORGIA INTO MONDAY IN WRAP-AROUND. BY
TUESDAY...SYSTEM LOOKS TO PULL FAR ENOUGH FROM THE STATE TO DROP
MENTION OF PRECIP...BUT SUSPECT SOME CLOUDINESS WILL LINGER.
LATEST GFS RUN SHOW NEXT POSSIBLE RAIN MAKER DEVELOPING OUT OVER
THE GULF TUESDAY/WEDNESDAY TIME FRAME WITH DEEPER MOISTURE
BEGINNING TO SPREAD INTO PORTIONS OF SOUTHWEST GEORGIA WEDNESDAY.
WILL CONTINUE DRY FORECAST FOR NOW...BUT IF LATER RUNS SUPPORT IT
MAY HAVE TO INTRODUCE POPS BACK INTO THE FORECAST WEDNESDAY.

&&

.HYDROLOGY...
HAVE ALREADY HAD WIDESPREAD 1 TO 2 INCHES OF RAIN ACROSS PORTIONS
OF NORTH GEORGIA TODAY...WITH ISOLATED 3 INCHES ACROSS SOME
EXTREME WESTERN COUNTIES. WILL NEED TO CONTINUE FLOOD WATCH
OVERNIGHT WITH AN ADDITIONAL 1 INCH OR BETTER POSSIBLE. MODELS
SHIFT FOCUS FOR HEAVIEST RAIN MORE DOWN ACROSS CENTRAL GEORGIA
THURSDAY/FRIDAY...IN THE AREA THAT HAS SEEN LESSER AMOUNTS OF RAIN
TODAY. GFS SHOWING 1 TO 2...WITH ISOLATED 3 INCHES. NO WATCH YET...
BUT LATER SHIFTS WILL NEED TO WATCH.

&&

.AVIATION...
A SERIES OF UPPER DISTURBANCES EMBEDDED WITHIN THE SW FLOW ALOFT
WILL KEEP A THREAT OF SHOWERS TRACKING SW TO NE ACROSS THE AREA
OVERNIGHT. A SUDO WEDGE WILL HOLD STRONG OVERNIGHT MAINTAINING A
COOL EASTERLY WIND FLOW. AREA RADARS AND MODEL DATA SUGGEST THE AREA
OF WIDESPREAD RA CURRENTLY ACROSS ATL AREA WILL SHIFT EAST AND
BECOME MORE SCT IN NATURE BY 03-04Z. WILL LEAN TOWARD TAKING THE
PREDOMINANT -RA OUT OF ATL BY 04Z. MAY SHOW A TEMPO RA GROUP FM
04-06Z... BUT WILL FINE TUNE THIS BEFORE TAF ISSUANCE. OTHERWISE...
EXPECT CURRENT IFR CIGS (BKN006) TO ACTUALLY IMPROVE TO MVFR
(BKN010-015) BY 00Z OR SO...THEN LOWER BACK TO IFR AND 2SM BR BY
06Z...THEN LIFR (OVC004) WITH 1/2SM -DZ FG BY 08Z IF NOT SOONER. VIS
SHOULD IMPROVE SLIGHTLY BY 12Z THEN CIGS TO IFR BY 15Z...THEN
POSSIBLY MVFR BY 18-20Z. GFS SHOWS ANOTHER ROUND OF STRONG SHOWERS
AND TSTMS MOVING ACROSS ATL AREA BETWEEN 15-21Z THU...WHILE NAM
TAKES THIS ACTIVITY SOUTH OF ATL. WILL SHOW PREDOMINATE -RA AND A
TEMPO SHRA GROUP FOR MUCH OF THU STARTING BY 15Z. /39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          49  63  49  64  47 / 100 100  30  60  60
ATLANTA         49  63  51  63  48 / 100 100  40  70  40
BLAIRSVILLE     48  59  47  58  47 /  90 100  30  60  60
CARTERSVILLE    50  63  48  63  44 / 100 100  40  70  40
COLUMBUS        54  69  55  70  48 /  90 100  50  60  30
GAINESVILLE     47  62  49  62  47 / 100 100  30  60  50
MACON           54  69  54  67  49 /  90 100  40  60  40
ROME            53  64  50  67  43 / 100 100  40  70  40
PEACHTREE CITY  49  64  48  65  44 / 100 100  40  70  40
VIDALIA         55  71  56  70  55 /  90 100  30  50  60

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THURSDAY MORNING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...COBB...DADE...DAWSON...DEKALB...DOUGLAS...FLOYD...
FORSYTH...GILMER...GORDON...GWINNETT...HALL...HARALSON...
JACKSON...LUMPKIN...MADISON...MURRAY...NORTH FULTON...PAULDING...
PICKENS...POLK...SOUTH FULTON...WALKER...WHITE...WHITFIELD.

&&

49

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
837 PM EST WED MAR 10 2010

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-111930-
BALDWIN-BANKS-BARROW-BARTOW-BIBB-BLECKLEY-BUTTS-CARROLL-CATOOSA-
CHATTAHOOCHEE-CHATTOOGA-CHEROKEE-CLARKE-CLAYTON-COBB-COWETA-
CRAWFORD-CRISP-DADE-DAWSON-DEKALB-DODGE-DOOLY-DOUGLAS-EMANUEL-
FANNIN-FAYETTE-FLOYD-FORSYTH-GILMER-GLASCOCK-GORDON-GREENE-
GWINNETT-HALL-HANCOCK-HARALSON-HARRIS-HEARD-HENRY-HOUSTON-JACKSON-
JASPER-JEFFERSON-JOHNSON-JONES-LAMAR-LAURENS-LUMPKIN-MACON-
MADISON-MARION-MERIWETHER-MONROE-MONTGOMERY-MORGAN-MURRAY-
MUSCOGEE-NEWTON-NORTH FULTON-OCONEE-OGLETHORPE-PAULDING-PEACH-
PICKENS-PIKE-POLK-PULASKI-PUTNAM-ROCKDALE-SCHLEY-SOUTH FULTON-
SPALDING-STEWART-SUMTER-TALBOT-TALIAFERRO-TAYLOR-TELFAIR-TOOMBS-
TOWNS-TREUTLEN-TROUP-TWIGGS-UNION-UPSON-WALKER-WALTON-WARREN-
WASHINGTON-WEBSTER-WHEELER-WHITE-WHITFIELD-WILCOX-WILKES-
WILKINSON-
837 PM EST WED MAR 10 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...THIS EVENING AND TONIGHT
SCATTERED THUNDERSTORMS ARE POSSIBLE THIS EVENING AND OVERNIGHT.

.SYNOPSIS...
A STORM SYSTEM OVER THE MIDWEST WILL REMAIN NEARLY STATIONARY AND
STRENGTHEN THROUGH TONIGHT. THIS WILL BRING RAIN AND SCATTERED
THUNDERSTORMS TO THE REGION.

.PRIMARY HAZARDS...
THE PRIMARY HAZARD FROM THE THUNDERSTORMS WILL BE CLOUD TO GROUND
LIGHTNING AND LOCALLY HEAVY RAIN.

.DISCUSSION...
WIDESPREAD SHOWERS WITH SCATTERED EMBEDDED THUNDERSTORMS WILL
CONTINUE OVER NORTH AND CENTRAL GEORGIA THROUGH TONIGHT. ALTHOUGH
INSTABILITIES WILL CONTINUE TO WEAKEN... A SERIES OF UPPER
DISTURBANCES WILL INTERACT WITH ABUNDANT LOW LEVEL MOISTURE
SPREADING NORTHWARD FROM THE GULF TO PRODUCE SHOWERS AND
THUNDERSTORMS OVERNIGHT. LACK OF INSTABILITY WILL GREATLY HINDER ANY
SEVERE THUNDERSTORM THREAT. BRIEF HEAVY DOWNPOURS OVER AN ALREADY
SATURATED GROUND COULD RESULT IN MINOR FLOOD PROBLEMS ALONG LOW
LYING...FLOOD PRONE AREAS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
THERE IS A CHANCE OF THUNDERSTORMS THURSDAY THROUGH FRIDAY NIGHT. A
FEW THUNDERSTORMS COULD BE STRONG TO SEVERE ON FRIDAY. HAZARDOUS
WEATHER IS NOT EXPECTED SATURDAY THROUGH TUESDAY

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED THROUGH TONIGHT.