Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
343 PM EDT WED MAY 16 2012

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
BOUNDARY CONTINUES TO CLEAR THROUGH SOUTH GEORGIA THIS AFTERNOON AND
EVENING. A 500 MB LOW...CURRENTLY OVER SOUTHERN MISSISSIPPI ON WATER
VAPOR IMAGERY...WILL PROGRESS EAST INTO GEORGIA ON THURSDAY. MUCAPE
VALUES REACHING 3000 J/KG OVER CENTRAL PORTIONS OF THE CWA LEND
ENOUGH SUPPORT TO THUNDERSTORMS ON THURSDAY AFTERNOON...ALTHOUGH 0-6
KM BULK SHEAR AND 0-1 KM BULK SHEAR VALUES ARE LACKING TO SUPPORT
SEVERE WEATHER. AS THE 500 MB LOW EASES INTO THE CAROLINAS...
PRECIPITATION SHOULD BE DECREASING THURSDAY NIGHT INTO FRIDAY.
DRIER AIR SHOULD ENTER THE REGION ON FRIDAY.

GENERALLY WENT SLIGHTLY WARMER THAN A BLEND OF MODEL GUIDANCE. MAV
WAS COOLER THAN THE MET. CONTINUING CLOUD COVER SHOULD AID IN
MODERATING BOTH MIN AND MAX TEMPS THROUGH THE SHORT TERM.

10

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HAVE MADE SOME MINOR TWEAKS TO POPS ON FRIDAY TO DELAY ONSET OF
PRECIPITATION IN THE MOUNTAINS...AS OROGRAPHIC UPLIFT LOOKS TO NOT
BE MUCH OF AN ISSUE UNTIL THE AFTERNOON. CAD HIGH CENTERS OVER THE
MID ATLANTIC STATES ON SATURDAY BUT WITH DRY ONSET DO NOT REALLY
EXPECT MUCH IN THE WAY OF SENSIBLE WEATHER IMPACTS. OTHERWISE NO
CHANGES PLANNED TO THE EXTENDED. PREVIOUS DISCUSSION INCLUDED
BELOW.

TDP

PREV DISCUSSION... /ISSUED 505 AM EDT WED MAY 16 2012/
EXTENDED PROGS SIMILAR WITH THE AXIS OF THE UPPER TROF LINGERING
OVER THE EAST SIDE OF THE STATE THURSDAY NIGHT...BUT APPEARS TO
SHIFT OUT OF THE AREA FRIDAY AS UPPER RIDGING STRENGTHENS TO OUR
WEST AND NORTHWEST. MODELS CONTINUE TO SHOW SURFACE HIGH PRESSURE
WEDGING DOWN THE APPALACHIANS FRIDAY AND REMAINING OVER THE AREA
THROUGH THE WEEKEND. MODELS HINTING AT THE HIGH WEAKENING AND
BEGINNING TO SHIFT OFF THE MID ATLANTIC COAST MONDAY-TUESDAY TIME
FRAME AS A COLD FRONT MOVES INTO THE LOWER MISSISSIPPI RIVER
VALLEY. HAVE CONTINUED SLIGHT CHANCE POPS EXTREME NORTH AND
EXTREME SOUTHEAST COUNTIES THURSDAY NIGHT/FRIDAY WITH UPPER TROF
STILL HAVING SOME INFLUENCE. SLIGHT CHANCE POPS MAINLY SOUTHEAST
COUNTIES SATURDAY INTO SUNDAY WITH MODELS SHOWING A WEAK UPPER LOW
MEANDERING NEAR THE FLORIDA PANHANDLE. LOW POPS MUCH OF THE AREA
MONDAY AND TUESDAY WITH THE FRONTAL BOUNDARY APPROACHING.

49

&&

.AVIATION...
18Z UPDATE...
VFR EXPECTED THROUGH THE PERIOD WITH A WIND SHIFT FROM THE WEST TO
THE EAST AFTER SUNRISE. SOME 4-5 KFT CLOUDS MAY ALSO DEVELOP AFTER
SUNRISE AND PERSIST THROUGH THE REST OF THE DAY WITH AVAILABLE
MOISTURE AND UPPER LEVEL SUPPORT. NOT EXPECTING PRECIPITATION AT
ANY OF THE FORECAST SITES...ALTHOUGH IT CANNOT BE RULED OUT.

//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON PRECIPITATION AND TIMING OF WIND SHIFT...
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
NAM BUFR APPEARED MORE IN LINE CURRENT CONDITIONS THAN THE GFS
BUFR...NOT MUCH SPREAD BETWEEN GUIDANCE.

10

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          61  87  61  80 /   5  20   5  10
ATLANTA         64  85  62  80 /   5  20   5  10
BLAIRSVILLE     55  79  56  77 /   5  20  10  20
CARTERSVILLE    55  87  59  82 /   5  20   5  20
COLUMBUS        64  88  62  82 /   5  10   5  10
GAINESVILLE     62  84  61  79 /  10  20  10  10
MACON           62  87  62  82 /  10  20  10  10
ROME            57  89  58  85 /   5  10   5  20
PEACHTREE CITY  56  85  59  80 /   5  10  10  10
VIDALIA         65  85  65  82 /  20  30  20  40

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...10
LONG TERM....TDP
AVIATION...10

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1145 AM EDT WED MAY 16 2012

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-171045-
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-
1145 AM EDT WED MAY 16 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...
SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH THIS EVENING.

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY STRETCHING FROM THE CENTRAL SECTIONS OF
THE CAROLINAS INTO SOUTHEAST GEORGIA WILL BE THE MAIN FOCUS FOR
THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE
AREA TODAY.

.PRIMARY HAZARDS...
THE PRIMARY HAZARDS ASSOCIATED WITH THE THUNDERSTORMS WILL BE BRIEF
HEAVY RAIN AND OCCASIONAL LIGHTNING. THE BEST CHANCE FOR
THUNDERSTORMS WILL BE THIS AFTERNOON AND EVENING. THE BEST LOCATION
FOR THUNDERSTORMS WILL BE EAST OF A COMMERCE TO CORDELE LINE.

.DISCUSSION...
A WEAK STATIONARY BOUNDARY ACROSS CENTRAL GEORGIA WILL AID IN THE
DEVELOPMENT OF SHOWERS AND SCATTERED THUNDERSTORMS ACROSS THE
AREA TODAY. CAPES VALUES ARE EXPECTED TO INCREASE INTO THE 1000 TO
1500 J/KG RANGE ACROSS THE AREA THIS AFTERNOON. A STORM OR TWO
COULD BE STRONG ESPECIALLY OVER EAST GEORGIA...BUT ALL STORMS ARE
EXPECTED TO STAY BELOW SEVERE LIMITS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...
THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS EACH DAY...MAINLY
DURING THE AFTERNOONS AND EVENINGS.

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
616 PM EDT WED MAY 16 2012

GAZ081>083-094-095-162300-
616 PM EDT WED MAY 16 2012

...SIGNIFICANT WEATHER ADVISORY FOR HEAVY RAIN AND STRONG WINDS IN
TWIGGS...PEACH...BIBB...CRAWFORD AND HOUSTON COUNTIES UNTIL 700 PM
EDT...

AT 613 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER BYRON...MOVING NORTHEAST AT 10 MPH.

THIS STORM HAS THE POTENTIAL TO PRODUCE PEA SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS IT MOVES ACROSS
TWIGGS...PEACH...BIBB...CRAWFORD AND HOUSTON COUNTIES THROUGH 700 PM
EDT. SOME LOCATIONS IN THE PATH OF THIS STORM INCLUDE LAKEWOOD...
POWERVILLE...BYRON...JACK BROWN ESTATES...CENTERVILLE...WARNER
ROBINS...ELBERTA...ROBINS AIR FORCE BASE...SKIPPERTON...MIDDLE
GEORGIA REGIONAL AIRPORT...HUBER AND RUTLAND. HEAVY DOWNPOURS WILL
CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3284 8362 3271 8344 3251 8372 3264 8387
TIME...MOT...LOC 2216Z 229DEG 10KT 3262 8374