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AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
700 AM EDT SAT AUG 29 2015

.PREV DISCUSSION... /ISSUED 332 AM EDT SAT AUG 29 2015/ 

SHORT TERM /TODAY THROUGH SUNDAY/...

UPPER LOW PRESSURE ALONG THE CENTRAL GULF COAST BRINGING DEEP MOISTURE
N ACROSS THE AREA TODAY AS A SHORT WAVE IN THE UPPER FLOW ENHANCES
SHWR CHANCES. SURFACE HIGH PRESSURE NOSING DOWN THE EASTERN APPALACHIANS
WILL AID IN A SHARP GRADIENT OF PRECIP CHANCES OVER THE FAR EASTERN
COUNTIES...MAKING IT A DIFFICULT POP FORECAST. FORECAST INSTABILITY
RATHER LOW SO THUNDERSTORMS CHANCES ARE RATHER MINIMAL WITH THE GREATEST
CHANCES OVER THE WESTERN AND SOUTHERN AREAS.

THE UPPER LOW IS FORECAST TO MOVE TO THE SOUTHERN APPALACHIANS FOR SUNDAY.
THIS WILL SHIFT THE GREATEST POPS TO THE NORTHERN AND EASTERN AREAS.
JUST A LITTLE MORE INSTABILITY FORECAST AS THE UPPER LOW MOVES TO THE NNE.

FORECAST HIGH TEMPERATURES RUNNING 5-10 DEGREES BELOW NORMAL TODAY AND
4-8 DEGREES BELOW NORMAL FOR SUNDAY.

OVERALL CONFIDENCE IS MEDIUM.

BDL

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

EXTENDED PORTION CONTINUES TO BE FRAUGHT WITH UNCERTAINTY DUE TO
THE PRECARIOUS STATUS OF TROPICAL STORM ERIKA AND THE RESULTANT
IMPACT ON MODEL GUIDANCE SOLUTIONS. LATEST OFFICIAL FORECAST FROM
THE HURRICANE CENTER HAS ERIKA TRACKING JUST TO THE WEST OF THE
FLORIDA PENINSULA AND WINDING UP AS A DEPRESSION OVER SOUTH
GEORGIA WED EVENING. THIS SOLUTION CONTINUES TO HAVE SUPPORT FROM
FROM THE LATEST ROUND OF OPERATIONAL MODELS INCLUDING THE GFS AND
TO A LARGE EXTENT THE PREVIOUS RUN OF THE ECMWF. THE BIG QUESTIONS
THEN BECOME...DOES ERIKA ACTUALLY FOLLOW THIS PATH OR DOES THE
TREND WESTWARD CONTINUE AND IF IT DOES FOLLOW THIS PATH...WHAT
HAPPENS AFTER IT MAKES ITS APPEARANCE OVER SOUTH GEORGIA.

FOR THIS FORECAST...WILL OF COURSE GO WITH THE NHC FORECAST
THROUGH WED EVENING AND THEN LEAN HEAVILY ON THE GFS FOR POP
DISTRIBUTION BUT SUBDUE THE REALLY HIGH VALUES BASED ON THE
CONTINUED UNCERTAINTY. SO FOR THE FORECAST...MONDAY COULD BE THE
FIRST DAY THAT WE REALLY SEE THE TROPICAL MOISTURE MAKE IT INTO
THE SOUTHERN SECTIONS OF THE FORECAST AREA. SHARP GRADIENT THOUGH
TO DEEP MOISTURE WITH ONLY 1.30 INCH PRECIPITABLE WATER VALUES
FROM THE ATLANTA METRO NORTHWARD. WILL GO AROUND LIKELY FROM CSG
TO MCN AND POINTS SOUTHWARD FOR THIS TIME PERIOD.

MAIN SLUG OF TROPICAL MOISTURE LOOKS TO SLOWLY CREEP NORTHWARD
THROUGH MID WEEK WITH 2 INCH PW VALUES ENCROACHING UPON ATLANTA
BY LATE WED AND TROPICAL MOISTURE ENGULFING MOST ALL OF THE AREA
BY FRIDAY. AGAIN...IN NORMAL CIRCUMSTANCES WITH THE VALUES
PRESENT...LIKELY POPS WOULD BE A GIVEN IF NOT HIGHER. BUT WITH THE
AMOUNT OF UNCERTAINTY PRESENT AND THE DISTINCT POSSIBILITY THAT
POPS COULD ACTUALLY BE BELOW CLIMO IF ERIKA TRACKS FURTHER
WEST...WILL LIMIT POPS TO HIGH END CHANCE FOR NOW. LIKEWISE...WILL
NOT GO AS COOL ON AFTERNOON HIGHS AS MODELS SUGGEST ON THE CHANCE
THAT WE SEE A DRIER WEEK THAN THE GFS IS ADVERTISING.

DEESE

&&

.AVIATION...
12Z UPDATE...
POTENTIAL FOR SOME IFR TO MVFR CEILINGS THIS MORNING BUT LOW
CONFIDENCE FOR HOW MUCH AND HOW LONG THEY WILL LAST. SHOWERS
DEVELOPING TODAY FAVORING THE WEST AND SOUTH AREAS.
SOME CHANCE FOR THUNDERSTORMS...MOST SO AT CSG.
SURFACE WINDS E-S LESS THAN 10 KTS.

//ATL CONFIDENCE...12Z UPDATE...
LOW CONFIDENCE FOR CEILINGS...VSBYS...AND PRECIP TIMING.
HIGH CONFIDENCE FOR WINDS.

BDL

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          84  68  81  67 /  40  40  70  30 
ATLANTA         82  68  82  69 /  60  50  70  30 
BLAIRSVILLE     80  63  76  62 /  30  40  60  30 
CARTERSVILLE    83  67  81  66 /  60  40  70  30 
COLUMBUS        81  70  86  71 /  70  60  40  20 
GAINESVILLE     82  67  78  67 /  50  40  70  30 
MACON           82  69  85  69 /  70  60  60  20 
ROME            84  68  82  66 /  50  40  60  30 
PEACHTREE CITY  81  68  83  68 /  60  60  60  20 
VIDALIA         86  71  86  71 /  60  60  70  30 

&&

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

$$

SHORT TERM...BDL
LONG TERM....DEESE
AVIATION...BDL

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