Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
135 PM EDT WED APR 4 2012

.UPDATE...
MADE SOME ADJUSTMENTS TO SKY COVER...POP AND WEATHER GRIDS FOR THIS
AFTERNOON AND EVENING TO FIT EXPECTED CONVECTIVE DEVELOPMENT. NO BIG
CHANGES TO THE OVERALL...12HR POPS OR WEATHER BUT ADJUSTED SOME
TIMING ELEMENTS ON THE 1-3 HOUR SCALE. STILL EXPECT A MORE RANDOM
THAN ORGANIZED NATURE TO THE CONVECTION THIS AFTERNOON UNDER WEAK
UPPER RIDGING...WITH SCATTERED COVERAGE ON AVERAGE ACROSS THE
FORECAST AREA. INSTABILITY INCREASES TO MODERATE LEVELS WITH ISOLATED
SEVERE STORMS POSSIBLE...BUT NOT EXPECTING THE THREAT TO BE
WIDESPREAD ENOUGH FOR A MENTION IN THE ZONES AT THIS TIME.

&&

.PREV DISCUSSION... /ISSUED 735 AM EDT WED APR 4 2012/

SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...

SOME WEAK RIDGING ALOFT OVER THE SOUTHEAST TODAY AHEAD OF THE
TEXAS CLOSED UPPER LOW. WITH DAYTIME HEATING AND LINGERING OUTFLOW
BOUNDARIES...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP
ACROSS THE CWA AGAIN TODAY...MAINLY THIS AFTERNOON INTO THIS
EVENING. CLOSED UPPER LOW WILL BE MOVING SOUTHEAST TOWARD THE
STATE THURSDAY AND THURSDAY NIGHT. DYNAMICS ASSOCIATED WITH THIS
SYSTEM WILL AFFECT THE CWA THURSDAY AND THURSDAY NIGHT. STRONG
SHEAR AND MODERATE INSTABILITY WILL GIVE THE POSSIBILITY OF A FEW
SEVERE THUNDERSTORMS OVER PORTIONS OF THE CWA DURING THAT TIME.
HAVE INCREASED POPS INTO THE LIKELY CATEGORY FOR THURSDAY INTO
THURSDAY NIGHT. UPPER LOW SHOULD BE MOVING EAST OF THE CWA TOWARD
FRIDAY MORNING. PERSISTENCE TEMPERATURES TODAY FAVORING THE WARMER
NUMBERS...HOWEVER THIS WILL BE AFFECTED BY AREAS OF CLOUDINESS.
NOT AS WARM ON THURSDAY WITH GREATER LIKELIHOOD OF CLOUDS AND
RAIN. IN GENERAL...A BLEND OF MAV/MET.

41

LONG TERM /FRIDAY THROUGH TUESDAY/...

AS THE SYSTEM EXITS THE REGION ON FRIDAY...00Z NAM AND 00Z ECMWF
KEEP SOME AVAILABLE INSTABILITY IN EASTERN PORTIONS OF THE CWA WITH
MUCAPE VALUES HOVERING AROUND 900-1500 J/KG. LIKELY WILL RESULT IN
SHOWERS WITH A SLIGHT CHANCE OF THUNDER MAINLY EAST...THOUGH THIS IS
HIGHLY DEPENDENT ON UPPER LEVEL LOW TRACK AND TIMING.

A RIDGE OF HIGH PRESSURE BUILDS IN TO START THE WEEKEND. LATE
SUNDAY INTO MONDAY...A WEAK FRONT ASSOCIATED WITH A LOW PRESSURE
SYSTEM IN THE GREAT LAKES REGION WILL MOVE THROUGH NORTH AND
CENTRAL GEORGIA. INCREASING CLOUDS AND A CHANCE OF SHOWERS ARE
ABOUT THE ONLY EFFECTS THIS FRONT WILL HAVE ON THE END OF THE
EASTER WEEKEND AND START OF THE NEXT WORK WEEK. 00Z GFS DOES NOT
EVEN GENERATE PRECIPITATION WITH THE FRONTAL PASSAGE. 00Z ECMWF
STILL GENERATES TOKEN AMOUNTS OF PRECIPITATION OVER NORTH CENTRAL
GEORGIA/METRO ATLANTA BEFORE THE FRONT PUTTERS OUT ON ITS WAY
EAST. NORTHWEST FLOW RETURNS TUESDAY WITH THE 00Z GFS AND 00Z
ECMWF HINTING AT PRECIPITATION POTENTIAL FROM SHORTWAVE TROUGHS
TRAVERSING THE REGION.

10

CLIMATE...

RECORDS FOR 04-04

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAHN      89 1934     47 1987     66 1999     29 1915
   KATL      85 1969     47 1987     66 1880     30 1987
                                                    1936
                                                    1891
   KCSG      87 1977     54 1987     64 1956     33 1987
                1967
                1954
   KMCN      88 1969     53 1987     69 1977     31 1992
                1954
                1934

PREV DISCUSSION...

AVIATION...
18Z UPDATE...
VFR CONDITIONS EXPECTED OUTSIDE OF CONVECTIVE ACTIVITY THROUGH 03Z.
SCATTERED MVFR...WITH LOCAL IFR...VISIBILITIES EXPECTED TO DEVELOP
BETWEEN 06Z AND 14Z. ONLY TAF SITES CURRENTLY FORECAST TO BE
IMPACTED ARE KFTY...KPDK...KAHN AND KMCN. WINDS REMAIN SOUTHWEST TO
NORTHWEST THROUGH THE PERIOD. WINDS SPEEDS WILL REMAIN 7-10KT
THROUGH 00Z...WITH OCCASIONAL GUSTS AS HIGH AS 16KT POSSIBLE...
DIMINISHING TO 2-6KT 00Z THROUGH 13Z...THEN INCREASING AGAIN INTO
THE 7-10KT RANGE AGAIN. ISOLATED CONVECTION 18Z-22Z BECOMING
SCATTERED THROUGH 02Z.

//ATL CONFIDENCE...18Z UPDATE...
MEDIUM TO HIGH ALL ELEMENTS.

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          84  60  78  53 /  40  40  70  60
ATLANTA         84  65  77  54 /  40  50  70  50
BLAIRSVILLE     79  56  72  52 /  40  50  70  70
CARTERSVILLE    84  60  79  51 /  40  50  70  50
COLUMBUS        85  66  82  54 /  40  40  70  30
GAINESVILLE     83  61  76  53 /  40  50  70  60
MACON           86  63  82  56 /  40  40  70  40
ROME            86  60  78  52 /  40  50  70  50
PEACHTREE CITY  83  60  78  51 /  40  40  70  40
VIDALIA         87  66  82  60 /  30  30  70  60

&&

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

20

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1244 PM EDT WED APR 4 2012

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-051645-
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-
1244 PM EDT WED APR 4 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...
SCATTERED THUNDERSTORMS ARE POSSIBLE ACROSS NORTH AND CENTRAL
GEORGIA TODAY AND TONIGHT. SOME OF THESE STORMS COULD BE
STRONG TO LOCALLY SEVERE.

.SYNOPSIS...
OUTFLOW BOUNDARIES FROM YESTERDAYS STORMS WILL PROVIDE THE FOCUS
FOR ADDITIONAL DEVELOPMENT TODAY. AN AREA OF HIGH PRESSURE IN THE
ATLANTIC IS ALLOWING DEEP GULF MOISTURE TO ENTER NORTH AND CENTRAL
GEORGIA AHEAD OF AN APPROACHING FRONTAL SYSTEM. THIS FRONTAL
SYSTEM WILL ALLOW FOR MORE ORGANIZED ACTIVITY DURING THE LAST HALF
OF THE OVERNIGHT PERIOD TOWARD DAYBREAK.

.PRIMARY HAZARDS...
THE PRIMARY HAZARDS FROM THESE THUNDERSTORMS WILL BE GUSTY
WINDS...HAIL...AND LIGHTNING.

.DISCUSSION...
AVAILABLE MOISTURE AND MODERATE TO HIGH INSTABILITY...WITH CAPE
VALUES OF 1500 TO 2500 J/KG THIS AFTERNOON AND EVENING...WILL
COMBINE WITH THE FORCING OF THE LINGERING OUTFLOW BOUNDARIES TO
ALLOW FOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS NORTH
AND CENTRAL GEORGIA. A SEPARATE LINE OF SHOWERS AND STORMS WILL
DEVELOP LATE TONIGHT TOWARD THURSDAY MORNING ALONG THE GULF COAST
REGION AND PERHAPS REACH THE SOUTHWEST PORTION OF THE FORECAST
AREA JUST PRIOR TO DAYBREAK.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...
THUNDERSTORMS WILL CONTINUE INTO THURSDAY WITH ADDITIONAL STRONG
TO LOCALLY SEVERE STORMS POSSIBLE. THIS ACTIVITY WILL INGER INTO
THURSDAY NIGHT AND INTO EARLY FRIDAY. NO HAZARDOUS WEATHER IS ANTICIPATED
SATURDAY THROUGH MONDAY AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ACTIVATION IS NOT REQUESTED BUT SPOTTERS ARE ENCOURAGED
TO SUBMIT REPORTS OF SEVERE WEATHER THROUGH THE WEB BY GOING TO
WEATHER.GOV/ATLANTA.

DEESE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1243 PM EDT WED APR 04 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0905 PM     TSTM WND DMG     5 N CROSS KEYS          32.92N 83.61W
04/03/2012                   JONES              GA   EMERGENCY MNGR

            EMERGENCY MANAGER REPORTED WIND DAMAGE TO A LARGE
            BARN...A HOME AND SEVERAL OUTBUILDINGS ON GRAHAM ROAD. A
            FEW LARGE HARDWOOD TREES WERE SNAPPED.

&&

20

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
324 PM EDT WED APR 4 2012

GAZ039-051-062-042000-
324 PM EDT WED APR 4 2012

...SIGNIFICANT WEATHER ADVISORY FOR DIME SIZED HAIL AND 40 MPH WINDS
IN WILKES...WARREN AND TALIAFERRO COUNTIES UNTIL 400 PM EDT...

AT 321 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER LUNDBERG...MOVING EAST AT 20 MPH.

THESE STORMS HAVE THE POTENTIAL TO PRODUCE DIME SIZED HAIL...FREQUENT
CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH AS THEY MOVE
ACROSS WILKES...WARREN AND TALIAFERRO COUNTIES THROUGH 400 PM EDT.
SOME LOCATIONS IN THE PATH OF THESE STORMS INCLUDE LUNDBERG...
FICKLIN...WASHINGTON...CARTERS GROVE...RAYTOWN...LYNEVILLE...
ALEXANDER STEPHENS PARK...SHARON...CRAWFORDVILLE...SANDY CROSS...
TYRONE...ROCKY CREEK FIRE DEPT....AONIA...METASVILLE AND HOLLIDAY
PARK. HEAVY DOWNPOURS WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 3363 8255 3363 8260 3360 8264 3356 8263
      3354 8297 3362 8298 3367 8295 3370 8300
      3373 8295 3374 8295 3378 8256 3366 8249
      3365 8249
TIME...MOT...LOC 1923Z 265DEG 16KT 3366 8269