838 
FXUS62 KFFC 202342
AFDFFC

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
742 PM EDT WED MAY 20 2015

.EVENING UPDATE...
UPPER DISTURBANCE PUSHING INTO NW AL IS SPARKING CONVECTION THERE... 
WITH ONGOING CONVECTION STILL NOTED ACROSS EAST AND SE AL. THESE 
STORMS MAY PUSH INTO THE COLUMBUS AREA BY 9 PM... BUT EXPECT SOME 
WEAKENING... SO MAY BE MOSTLY SHOWERS. THE GREATER CONCERN IS THE 
CONVECTION TO THE NORTH WHERE HAS BETTER UPPER SHORT WAVE SUPPORT. 
THIS CONVECTION WILL LIKELY SPREAD ISOLATED TO POSSIBLY STILL 
SCATTERED THUNDERSTORMS INTO NW GA BETWEEN 9-10 PM... THEN SPREAD 
ACROSS THE REST OF NORTH GA THROUGH MIDNIGHT AND COULD PERSIST UNTIL 
AROUND 2-3 AM THU MORNING. NO SEVERE STORMS ARE EXPECTED... WITH THE 
MAIN THREAT BEING OCCASIONAL CLOUD TO GROUND LIGHTNING AND BRIEF 
WIND GUSTS TO 35-40MPH OR SO. WILL UP POPS OVER THE NW ZONES AS GET 
MORE CONFIDENT THE CONVECTION WILL HOLD TOGETHER... BUT OTHERWISE... 
THE CURRENT FORECAST LOOK ON TRACK. 39


.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
MAIN FORECAST CONCERN IS WITH PRECIP POTENTIAL THIS EVENING INTO THE 
EARLY MORNING AS A SHORTWAVE AND SOME ENHANCED MOISTURE APPROACHES 
THE CWA FROM THE WEST. CURRENTLY A BAND OF SHOWERS AND STORMS IS 
PUSHING INTO WESTERN ALABAMA AHEAD OF THIS DISTURBANCE WITH A WEAK 
TRANSLATED SFC LOW. WHILE SOME HI-RES SOLUTIONS DO NOT APPEAR TO 
SUPPORT THIS HOLDING TOGETHER AND PUSHING INTO WEST GA...SOME 
PREVIOUS RAP SOLUTIONS SUPPORTED IT AND WILL NEED TO BE CLOSELY 
MONITORED ESPECIALLY IF SOME OUTFLOW BOUNDARIES OR OTHER MESOSCALE 
FORCING COMES TO AID. THIS MAY RESULT IN UPPING POPS IN WESTERN 
PORTIONS OF THE AREA BY THIS EVENING. STILL SOME MLCAPE NEAR 1000 
J/KG AND DECENT DCAPE IN PLACE. IF ANY STORM DEVELOPMENT CAN 
MUSTER...THERE COULD STILL BE STRONG DOWNDRAFT WINDS EVEN THOUGH IT 
IS A SHEAR DEPRIVED ENVIRONMENT. KEEPING BEST CHANCE POPS MAINLY 
NORTH OF I-20 CORRIDOR INTO THE EARLY MORNING WITH THE SHORTWAVE 
INFLUENCE.

PROGGED THERMAL PROFILES INDICATE GOOD DRYING OF THE COLUMN FOR 
THURSDAY AND NOW BETTER AGREEMENT WITH A NOTABLE CAPPING INVERSION 
ABOVE 850 MB. HAVE TRIMMED BACK POPS NOW TO ONLY HAVE A SLIGHT 
CHANCE IN THE FAR SOUTHERN TIER FOR THE AFTERNOON...OTHERWISE 
LOOKING TO STAY TOO DRY AND STABLE. WINDS LOOK TO BE KICKING IN WITH 
THE STRENGTHENING PRESSURE GRADIENT AND AFTERNOON MIXING. WHILE 
CURRENTLY LOOKING TO STAY A BIT BELOW CRITERIA...WILL NEED TO KEEP 
AN EYE ON TRENDS FOR ANY FIRE DANGER CONCERNS WITH ALREADY DRY FUELS 
/THOUGH MAY BE ALTERED WITH AFOREMENTIONED PRECIP CHANCES/. TEMPS 
THURSDAY LOOK TO HAVE A STRONG GRADIENT WITH BELOW NORMAL HIGHS IN 
THE MID/UPPER 70S FOR THE NW TO THE LOW 90S SE.

BAKER


.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
HAVE MADE A FEW MINOR ADJUSTMENTS TO POP AND WEATHER THROUGH THE
WEEKEND. LATEST LONG TERM MODELS HINT AT A MORE PROMINENT SURFACE
HIGH KEEPING MOISTURE TO THE WEST LARGELY AT BAY THROUGH
SUNDAY...WITH ONLY PORTIONS OF WESTERN AND NORTHERN GEORGIA AT
RISK FOR AN ISOLATED STORM. HAVE SCALED POPS BACK SOMEWHAT AS A
RESULT.

31


PREV DISCUSSION... /ISSUED 424 AM EDT WED MAY 20 2015/ 
LONG TERM PERIOD BEGINS A BIT DRIER AS THE FRONTAL SYSTEM WILL BE
SOUTH AND EAST OF THE AREA. HIGH PRESSURE BUILDING IN FROM THE
NORTHERN PLAINS AND MID WESTERN STATES BECOMES CENTERED OFF THE
MID ATLANTIC COAST AND STAYS THERE THROUGH THE WEEKEND. THIS RIDGE
CONTINUES TO ROTATE AND KEEPS THE DEEPER MOISTURE NORTH AND WEST
OF THE REGION THROUGH THE BEGINNING OF NEXT WEEK. THERE IS STILL
SOME MID AND UPPER LEVEL MOISTURE AROUND THE AREA SO WILL KEEP
SLIGHT CHANCE DIURNALLY DRIVEN POPS IN THE FORECAST DAYS 3-5. BY
TUESDAY THE RIDGE IS BEGINNING TO WEAKEN AND TRANSITION INTO MORE
OF A BERMUDA LIKE RIDGE. THIS WILL ALLOW DEEPER MOISTURE TO MOVE
IN FROM THE WEST ASSOCIATED WITH A WEAKENING FRONTAL BOUNDARY.
LOOKING AT INSTABILITIES INCREASING A BIT TUESDAY/WEDNESDAY ALONG
WITH PWS SO WILL INCREASE TO CHANCE POPS DAYS 6 AND 7.

01

&&

.AVIATION...
00Z UPDATE...
UPPER DISTURBANCE WILL SPREAD SCATTERED SHOWERS AND A FEW 
THUNDERSTORMS INTO THE ATLANTA TAF SITES BETWEEN 02-06Z THU... WITH 
MID LEVEL CIGS EXPECTED BY 01-02Z. MOS GUIDANCE IS STILL SHOWING A 
CHANCE OF MVFR CIGS AT ATL AROUND 09-15Z THU MORNING. THESE SHOULD 
SCT BY 15Z THU WITH FEW-SCT050 EXPECTED THU AFTERNOON. WINDS MAINLY 
WNW 3-6 KTS TONIGHT...THEN INCREASE TO 10-12 KTS BY 15-16Z THU WITH 
OCCASIONAL HIGHER GUSTS OF 18-22 KTS EXPECTED BY 16-18Z THU. THE 
GUSTS SHOULD END BY 00-02Z FRI.  

//ATL CONFIDENCE...00Z UPDATE...
MEDIUM ON LATE EVENING CONVECTION BEING THUNDERSTORMS AND MVFR CIGS 
BY 09Z. HIGH ON ALL ELSE.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          66  85  56  81 /  20  10  10   5 
ATLANTA         67  80  58  80 /  30  10   5   5 
BLAIRSVILLE     61  74  48  74 /  30  20  10   5 
CARTERSVILLE    64  79  53  79 /  30  10   5   5 
COLUMBUS        70  88  61  84 /  10  10  10   5 
GAINESVILLE     65  80  55  78 /  30  10  10   5 
MACON           67  89  59  85 /  20  10  10   5 
ROME            65  77  52  79 /  40  10  10   5 
PEACHTREE CITY  65  83  54  81 /  20  10   5   5 
VIDALIA         71  92  65  86 /  30  20  10   5 

&&

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

$$

SHORT TERM...BAKER
LONG TERM....31
AVIATION...BAKER