Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1048 PM EDT MON JUN 27 2011

.UPDATE...
CURRENT FORECAST LOOKS GOOD FOR THE REMAINDER OF TONIGHT. POPS
ALREADY LOWERED TO CHANCE/SLIGHT CHANCE RANGE. ATMOSPHERE STABILIZING
SOMEWHAT...BUT WITH CONTINUING NORTHWEST UPPER FLOW...AND NEW
CONVECTION FIRING UPSTREAM IN THE MID MISSISSIPPI AND WESTERN OHIO
VALLEYS...I DO NOT FEEL A COMPLETE REMOVAL OF POPS IS WARRANTED AT
THIS TIME.

&&

.PREV DISCUSSION... /ISSUED 755 PM EDT MON JUN 27 2011/

UPDATE...
REDUCED POST 00Z POPS BASED ON CURRENT RADAR TRENDS AND LATEST
MODEL SOLUTIONS. INHIBITING FACTOR SEEMS TO BE HIGH PRESSURE RIDGE
NOSING INTO THE REGION...AND LOOKS LIKE BEST OPPORTUNITY FOR
ACTIVITY WILL BE ACROSS FAR NORTH GEORGIA. UNCERTAINTY STILL HIGH
WITH THE OVERNIGHT POPS AND WEATHER GIVEN THAT MODELS HAVE NOT
REPRESENTED THE MCS AND AFTERNOON CONVECTION WELL. WILL MAKE
UPDATES AS NECESSARY.

31

PREV DISCUSSION...

SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
/ISSUED 353 PM EDT MON JUN 27 2011/
DIFFICULT PRECIP FORECAST OVER THE NEXT 24 TO 48 HOURS DUE TO LACK
OF CONSENSUS BETWEEN THE MODELS. ALTHOUGH MORNING AND EARLY
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY HAS BEGUN TO TAPER
OFF...EXPECT SECOND WAVE OF CONVECTION BY EARLY EVENING. MCS IN THE
TN VALLEY IS EXPECTED TO DROP SOUTHWARD INTO AL AND GA LATER TODAY.
AS A RESULT...A FEW OF THE SHORT RANGE...HI RES MODELS ARE
INDICATING ADDITIONAL THUNDERSTORM DEVELOPMENT NOT TOO DISSIMILAR TO
THE ACTIVITY YESTERDAY. EXPECT THIS SECOND WAVE TO BE MORE ORGANIZED
THAN THE PULSE ACTIVITY THIS MORNING...BUT WITH LITTLE TO NO POPS IN
THE MAV AND MET...UNCERTAINTY IS HIGH. HAVE GONE AGAINST GUIDANCE
AND INDICATED GOOD CHANCE TO LIKELY POPS OVERNIGHT. PRIMARY HAZARDS
ASSOCIATED WITH THIS ACTIVITY WILL BE FREQUENT LIGHTNING...AND
DAMAGING WINDS...ALTHOUGH SMALL HAIL IS NOT OUT OF THE QUESTION.

MODELS IN BETTER AGREEMENT TUESDAY...WITH COLD FRONT PUSHING ACROSS
THE STATE INTO CENTRAL GEORGIA BY EARLY WEDNESDAY. EXPECT DIURNAL
HEATING TO INCREASE INTENSITY AND COVERAGE OF THE ACTIVITY...SO HAVE
GONE WITH LIKELY TO CATEGORICAL POPS THROUGH THE DAY...AND THEN GOOD
CHANCE OVERNIGHT TUESDAY INTO WEDNESDAY. FRONT PUSHES INTO SOUTHERN
GEORGIA AND NORTHERN FLORIDA BY WEDNESDAY NIGHT...SO HAVE CONTINUED
WITH GOOD CHANCE TO LIKELY POPS ACROSS THE VERY SOUTHERN PORTION OF
THE CWA. SPC ALREADY HAS PORTIONS OF WESTERN GA IN THE SLIGHT RISK
AREA FOR DAY 2.

AS FAR AS TEMPERATURES ARE CONCERNED...HAVE GONE WITH SLIGHTLY
COOLER THAN MAV TEMPS FOR HIGHS AND SLIGHTLY WARMER THAN MAV/MET FOR
LOWS TO ACCOUNT FOR AMPLE CLOUD COVER AND PRECIP ACTIVITY.

31

LONG TERM /THURSDAY THROUGH MONDAY/...
/ISSUED 353 PM EDT MON JUN 27 2011/
STRONG 500 MB HIGH PRESSURE RIDGE DEVELOPS OVER THE CENTRAL US BY
LATE WEEK AND INTO THE WEEKEND. AS THIS RIDGE REMAINS IN PLACE
THROUGH THE LONG TERM...EXPECT GENERALLY DIURNALLY DRIVEN
CONVECTION. WITH NO MAJOR CHANGES IN MODEL SOLUTIONS THROUGH NEXT
WEEK...HAVE CONTINUED WITH THE CURRENT FORECAST WITH LITTLE
REVISIONS.

31

AVIATION...
/ISSUED 744 PM EDT MON JUN 27 2011/
00Z UPDATE...
NO SIGNIFICANT CONCERNS WITH AVIATION FORECAST. TSRA AND CUMULUS
FIELD ACROSS NORTH ATL METRO HAVE MOSTLY DISSIPATED. STRONGER
WESTERLY FLOW ALOFT REMAINING JUST TO THE NORTH OF THE STATE...SO
OVERNIGHT STORMS SHOULD REMAIN IN TN VALLEY...POSSIBLY REACHING
FAR NORTH GA. EXPECT TSRA ACROSS THE REGION SHOULD REMAIN AWAY FROM
TAF SITES SO HAVE REMOVED FROM FCST FOR TONIGHT. COULD SEE SOME
PATCHY MVFR VSBYS AT AIRPORTS PRONE TO RADIATIONAL COOLING
/KFTY...KMCN...KAHN/ 11Z-13Z BUT NOT MUCH ELSE. SFC WINDS TO KEEP
W TO SW COMPONENT ALL DAY TUES AND EXPECT ANOTHER ROUND OF
SCATTERED TSRA AFTER 22Z. THIS TIMING MATCHES LATEST GROUP OF 4KM
MODELS WELL. TEMPO TSRA MAY BE REDUCED TO PROB30 IN LATER UPDATES
BASED ON EXPECTED AREAL COVERAGE.

//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE IN TSRA COVERAGE.
HIGH CONFIDENCE IN ALL OTHER ELEMENTS.

13

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          72  94  71  94 /  40  60  50  20
ATLANTA         74  90  73  92 /  40  60  50  20
BLAIRSVILLE     67  85  68  89 /  40  70  50  10
CARTERSVILLE    69  91  69  91 /  40  70  50  10
COLUMBUS        73  93  75  93 /  40  60  50  50
GAINESVILLE     73  89  71  89 /  40  70  50  10
MACON           72  94  73  94 /  40  60  50  50
ROME            70  93  69  90 /  40  70  50  10
PEACHTREE CITY  69  91  70  91 /  40  60  50  20
VIDALIA         73  91  76  92 /  40  60  50  60

&&

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

20

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1127 PM EDT MON JUN 27 2011

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-290330-
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-
1127 PM EDT MON JUN 27 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...TONIGHT
ISOLATED THUNDERSTORMS ARE POSSIBLE TONIGHT ACROSS NORTH AND
CENTRAL GEORGIA.

.SYNOPSIS...
THUNDERSTORMS HAVE DISSIPATED ACROSS MOST OF THE REGION THIS
EVENING.

.DISCUSSION...
THE ATMOSPHERE HAS STABILIZED THIS EVENING...HOWEVER ISOLATED
STORMS COULD DEVELOP AFTER MIDNIGHT. ANY STORMS THAT DEVELOP
TONIGHT ARE EXPECTED TO REMAIN BELOW SEVERE LEVELS. STORMS IN THE
TENNESSEE AND OHIO VALLEYS ARE EXPECTED TO REMAIN NORTH OF THE
STATE THROUGH TONIGHT BUT COULD APPROACH FAR NORTH GEORGIA BY
DAYBREAK.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED TUESDAY...A FEW
OF WHICH COULD BE SEVERE. ISOLATED THUNDERSTORMS ARE POSSIBLE THE
REST OF THE WEEK.

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
120 AM EDT TUE JUN 28 2011

GAZ015-016-280545-
120 AM EDT TUE JUN 28 2011

...SIGNIFICANT WEATHER ADVISORY FOR FREQUENT LIGHTNING IN WHITE AND
LUMPKIN COUNTIES UNTIL 145 AM EDT...

AT 117 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER GARLAND...MOVING NORTHEAST AT 15 MPH.

LIGHTNING DETECTION SYSTEMS INDICATE NUMEROUS CLOUD-TO-GROUND
LIGHTNING STRIKES ACROSS WHITE AND LUMPKIN COUNTIES...INCLUDING AREAS
AROUND GARLAND...DAHLONEGA...PORTER SPRINGS...TURNERS CORNER...
WHITLEY GAP SHELTER...MOSSY CREEK...QUALATCHEE LAKE...SMITHGALL WOODS
CONSERVATION AREA...CAMP COLEMAN LAKE AND CLEVELAND. RESIDENTS IN
THIS AREA SHOULD STAY INDOORS. ELECTRICAL APPLIANCES AND TELEPHONES
SHOULD NOT BE USED UNLESS IN AN EMERGENCY.

&&

LAT...LON 3453 8364 3450 8377 3452 8378 3450 8380
      3450 8384 3447 8388 3447 8393 3446 8393
      3445 8398 3455 8405 3476 8379
TIME...MOT...LOC 0521Z 245DEG 13KT 3453 8391

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
145 AM EDT TUE JUN 28 2011

GAZ015-016-280615-
145 AM EDT TUE JUN 28 2011

...SIGNIFICANT WEATHER ADVISORY FOR EXCESSIVE LIGHTNING IN WHITE AND
LUMPKIN COUNTIES UNTIL 215 AM EDT...

AT 140 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER GARLAND...MOVING NORTHEAST AT 10 MPH.

LIGHTNING DETECTION SYSTEMS INDICATE NUMEROUS CLOUD-TO-GROUND
LIGHTNING STRIKES ACROSS WHITE AND LUMPKIN COUNTIES...INCLUDING AREAS
AROUND GARLAND...PORTER SPRINGS...WHITLEY GAP SHELTER...LEAF...
QUALATCHEE LAKE...SMITHGALL WOODS CONSERVATION AREA...CAMP COLEMAN
LAKE...CLEVELAND AND TURNERS CORNER. RESIDENTS IN THIS AREA SHOULD
STAY INDOORS. ELECTRICAL APPLIANCES AND TELEPHONES SHOULD NOT BE USED
UNLESS IN AN EMERGENCY.

&&

LAT...LON 3456 8365 3448 8392 3458 8404 3473 8387
      3473 8383 3476 8383 3478 8381
TIME...MOT...LOC 0545Z 214DEG 9KT 3457 8391