Special Weather Statement, NWS Atlanta, GA

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
900 PM EDT WED JUL 31 2013

.UPDATE...
MID LEVEL WAVE SEEMS TO BE DRIVING THE CONVECTION OVER EASTERN AL.
THE MOST UNSTABLE PORTION OF THE AIRMASS IS ALONG THE GA/AL
BORDER FROM ABOUT CARROLL COUNTY N. THE FEELING IS ANY
THUNDERSTORMS WILL WEAKEN AS THEY MOVE EAST. BDL

&&

.PREV DISCUSSION... /ISSUED 710 PM EDT WED JUL 31 2013/

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
INITIAL...MAIN...SHORT WAVE IS TRAVERSING THE REGION THIS
AFTERNOON AND WILL BE EAST OF THE FORECAST AREA BY LATE THIS
EVENING. SATELLITE TRENDS SHOW THE CONVECTION THAT HAS BEEN FIRING
UPSTREAM IN THE NORTHWEST UPPER FLOW HAS NOT BEEN VERY ACTIVE.
HOWEVER THE POTENTIAL FOR WEAK WAVES INHERENT IN THIS TYPE OF
REGIME INDICATES DECENT POPS ARE IN ORDER FOR TONIGHT...ALTHOUGH I
WILL BE LETTING THEM DIMINISH FROM LIKELY TO HIGH CHANCE THROUGH
THE EVENING. WEAK SURFACE BOUNDARY AND DRIER AIRMASS MOVES INTO
THE AREA FROM NORTHWEST TO SOUTHEAST TOMORROW WITH DIMINISHING
RAIN CHANCES. APPEARS DRY AIR INFILTRATES FAR ENOUGH SOUTH TO SHUT
OFF ALL POPS FOR THE FORECAST AREA BY LATE THURSDAY.

RAIN-COOLED ATMOSPHERE SEEMS TO HAVE LIMITED INSTABILITY ENOUGH
ACROSS THE AREA TO KEEP CONVECTION BELOW SEVERE LIMITS...AND I
EXPECT THIS TREND WILL CONTINUE. AS ALWAYS WITH A NORTHWEST FLOW
SET-UP...WE WILL NEED TO KEEP A CLOSE WATCH UPSTREAM FOR ANY
INCREASE IN INTENSITY OR COVERAGE. ALTHOUGH PRECIPITABLE WATER
VALUES ARE WELL ABOVE SEASONAL NORMALS...STEADY MOVEMENT OF THE
HEAVIER PRECIPITATION SHOULD KEEP WIDESPREAD FLOODING POTENTIAL TO
A MINIMUM.

20

LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE FLOW SORT OF FLATTENS OUT AT THE BEGINNING OF THE PERIOD AS
RIDGING OVER THE SOUTHERN PLAINS PUSHES EAST. THIS WILL LEAD TO AT
LEAST A BRIEF DRYING TREND ACROSS THE AREA FRIDAY INTO SATURDAY.
WILL SEE A SLIGHT INCREASE IN TEMPS BUT GENERALLY STILL REMAINING
NORMAL TO JUST BELOW. ANOTHER SHORTWAVE DIGS DOWN THE FLOW
INCREASING THE AMPLITUDE OF THE OVERALL WAVE TRAIN LATE ON
SATURDAY...PUTTING US FIRMLY INTO NORTHWEST FLOW ALOFT AGAIN ON
SUNDAY. ECMWF IS QUITE A BIT WETTER THAN GFS INTO THE BEGINNING OF
NEXT WEEK BUT OVERALL A GENERALLY UNSETTLED WEATHER PATTERN
REMAINS IN PLACE THROUGH NEXT WEEK. MADE ONLY MINOR CHANGES TO THE
EXTENDED...MAINLY TO REFRESH DATA FOR PERIOD 4 AND TO INCREASE
POPS JUST A TAD FOR THE BEGINNING OF THE WORK WEEK.

TDP

PREV DISCUSSION... /ISSUED 431 AM EDT WED JUL 31 2013/
AT THE BEGINNING OF THE PERIOD A WEAK FRONTAL BOUNDARY WILL BE
MOVING INTO CENTRAL GEORGIA.  CONVECTION ASSOCIATED WITH THIS
BOUNDARY MAY BE ONGOING.  EXPECT THIS CONVECTION TO BE ON A GENERAL
WEAKENING TREND THROUGH THE EVENING.  AT THIS POINT FRIDAY LOOKS TO
BE THE BEST DAY FOR NO POPS ACROSS THE REGION AS WE WAIT FOR
NORTHWEST FLOW TO BRING US ANOTHER IMPULSE AND RAIN TO THE AREA.
MOISTURE ASSOCIATED WITH DORIAN SHOULD HELP IN INCREASE PWATS AND
RAIN CHANCES THIS WEEKEND AND INTO NEXT WEEK. THE MODELS SUGGEST
THAT WE KEEP NORTHWEST FLOW THROUGH AT LEAST MID NEXT WEEK...WHEN
THEY TRY TO BUILD A RIDGE INTO THE SOUTHERN UNITED STATES.  MAY
CONCERN IN THE EXTENDED COULD BE RAINFALL ASSOCIATED WITH THE
SHOWERS AND THUNDERSTORMS THIS WEEKEND AND INTO EARLY NEXT WEEK.
THIS WILL NEED TO BE MONITORED CLOSELY FOR POSSIBLE FLOODING AS WE
APPROACH THIS WEEKEND.

ARG

AVIATION...
00Z UPDATE...
CONCERN FOR THUNDERSTORMS TO DEVELOP OVER THE FORECAST AREA TONIGHT
WITH LOW CONFIDENCE FOR IMPACTS TO THE TAF SITES. OTHERWISE A MIX
OF MVFR TO HIGH VFR CEILINGS TRENDING TO IFR CEILINGS LATE TONIGHT
WITH MVFR AND POSSIBLY IFR VSBYS. SURFACE WINDS SSE-SW 5 KTS OR
LESS OR CALM.

//ATL CONFIDENCE...00Z UPDATE...
LOW CONFIDENCE FOR THUNDERSTORM IMPACTS OVERNIGHT.
MEDIUM CONFIDENCE OTHER ELEMENTS.

BDL

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          81  70  88  69 /  80  50  40  10
ATLANTA         77  71  87  70 /  80  50  40  10
BLAIRSVILLE     78  66  83  63 /  90  50  30  10
CARTERSVILLE    79  69  87  66 /  90  60  40  10
COLUMBUS        78  73  89  72 /  80  50  50  20
GAINESVILLE     80  71  87  70 /  80  50  40  10
MACON           77  73  88  71 / 100  50  50  20
ROME            78  69  87  67 /  90  60  30  10
PEACHTREE CITY  79  70  87  67 /  90  50  40  10
VIDALIA         86  72  88  72 /  80  50  60  20

&&

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

SHORT TERM...BDL
LONG TERM....39
AVIATION...BDL

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
620 PM EDT WED JUL 31 2013

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-011100-
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-
620 PM EDT WED JUL 31 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH AND CENTRAL
GEORGIA.

.DAY ONE...REST OF TONIGHT...

ISOLATED THUNDERSTORMS REMAIN POSSIBLE OVERNIGHT.

WEATHER HAZARDS EXPECTED...

BRIEF WIND GUSTS TO 40 MPH... OCCASIONAL LIGHTNING AND LOCALIZED
HEAVY RAIN.

DISCUSSION...

A SERIES OF UPPER DISTURBANCES WILL INTERACT WITH MODERATE
INSTABILITY AND AMPLE LOW LEVEL MOISTURE TO PRODUCE SCATTERED
SHOWERS... AND POSSIBLY A FEW THUNDERSTORMS THROUGH TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

THUNDERSTORMS POSSIBLE EACH DAY ACROSS THE AREA.

DISCUSSION...

ACTIVE WEATHER PATTERN SHOULD LEAD TO THUNDERSTORMS EACH DAY WITH
FRIDAY HAVING THE LOWEST CHANCE. WITH THE ACTIVE WEATHER PATTERN
FLOODING COULD RETURN AS A CONCERN TO THE AREA AS WELL.

.SPOTTER INFORMATION STATEMENT...

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
909 PM EDT WED JUL 31 2013

GAZ019-030-041-010200-
909 PM EDT WED JUL 31 2013

...SIGNIFICANT WEATHER ADVISORY FOR HEAVY RAIN AND 40 MPH WIND GUSTS
IN POLK...FLOYD AND HARALSON COUNTIES UNTIL 1000 PM EDT...

AT 908 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR ETNA...AND MOVING EAST AT 15 MPH.

WIND GUSTS OF 40 MPH...BRIEF HEAVY RAIN AND OCCASIONAL CLOUD TO
GROUND LIGHTNING ARE LIKELY AS THIS STORM MOVES ACROSS POLK...SOUTH
FLOYD AND NORTH HARALSON COUNTIES THROUGH 1000 PM EDT. SOME
LOCATIONS IN THE PATH OF THE STORM INCLUDE ESOM HILL...ETNA...CAVE
SPRING...FELTON...CEDARTOWN...ANTIOCH...EUBANK LAKE... DRAKETOWN...
SENEY...FISH CREEK...VAN WERT...ROCKMART...ARAGON AND LINDALE.

&&

LAT...LON 3437 8501 3432 8503 3422 8503 3421 8505
      3409 8504 3408 8501 3395 8502 3395 8505
      3391 8505 3390 8503 3382 8504 3383 8538
      3412 8543
TIME...MOT...LOC 0108Z 259DEG 14KT 3399 8539