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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
217 PM EST FRI DEC 26 2014

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
OUR NEXT WEATHER SYSTEM IS CURRENTLY DEEPENING OVER THE PLAINS... 
AND STILL PROGGED BY SHORT TERM MODELS TO BEGIN SPREADING AT LEAST 
LIGHT RAIN INTO THE WESTERN PORTIONS OF THE FORECAST AREA ON 
SATURDAY. MODELS ARE SLOWING THE SYSTEM DOWN A BIT... BUT CONTINUE 
TO SHOW THE GREATER RAIN CHANCES SATURDAY NIGHT AND SUNDAY AS THE 
ASSOCIATED SURFACE LOW AND COLD FRONT PUSH ACROSS THE LOWER MS 
VALLEY REGION SATURDAY NIGHT... THEN INTO NORTH GA ON SUNDAY. THE 
MORNING MODEL RUNS HAVE BACKED OFF ON SPREADING ANY MUCAPE 
/INSTABILITY/ INTO THE AREA ON SUNDAY... BUT WITH SURFACE LOW AND 
COLD FRONT PUSHING INTO NORTH GA SUNDAY AFTERNOON WITH AN ACTIVE SW 
FLOW ALOFT... SUSPECT AT LEAST NORTH GA WILL HEAR RUMBLES OF 
THUNDER. HAVE DECIDED TO HOLD ONTO ISOLATED THUNDER FOR ALL AREAS 
SUNDAY AFTERNOON... BUT NO SEVERE STORMS ARE EXPECTED. THE GREATER 
RAINFALL AMOUNTS ARE EXPECTED ACROSS NORTH GA SATURDAY NIGHT AND 
SUNDAY... WHERE AN INCH OR MORE IS EXPECTED THROUGH SUNDAY 
AFTERNOON. 

AS FOR TEMPS... LEANED SLIGHTLY COOLER THAN GUIDANCE FOR LOWS 
TONIGHT WITH A LIGHT/COOL EASTERLY FLOW AND ONLY HIGH CLOUDS 
SPREADING INTO THE STATE LATE TONIGHT. OTHERWISE... EXPECT 
UNSEASONABLE WARM LOWS AND HIGHS THROUGH THE SHORT TERM... 
WITH EACH RUNNING 10 TO 15 DEGREES ABOVE NORMAL.

39

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AFOREMENTIONED PRECIPITATION IS ONGOING AT THE ONSET OF THE
EXTENDED WITH BOTH THE GFS AND ECMWF BRINGING WIDESPREAD PRECIP
ACROSS THE AREA SUNDAY NIGHT. PRETTY MUCH ALL INSTABILITY IS GONE
OVERNIGHT SO KEPT WEATHER WORDING AT SHOWERS...BUT WITH PRETTY
HIGH POPS OVERNIGHT /CATEGORICAL UP NORTH/ TO ACCOUNT FOR THE
WIDESPREAD MOISTURE. GFS REMAINS A TAD FASTER WITH EXITING THE
BULK OF THE PRECIP ON MONDAY /THOUGH IT DOES ALLOW SOME LIGHT
PRECIP TO LINGER/ SO HAVE TAKEN A BIT OF A COMPROMISE. 

AFTER THE SYSTEM EXITS...WEAK SOUTHWEST FLOW ALOFT PREVAILS EARLY
IN THE WORK WEEK AS SURFACE HIGH PRESSURE DIGS OUT OF SOUTHERN
CANADA INTO THE PLAINS. THE HIGH MODIFIES SOMEWHAT AS IT WORKS
DOWN THE LEE OF THE ROCKIES UNDER THE CONFLUENT FLOW ALOFT...
FINALLY RIDGING INTO THE SOUTHEAST BY MIDWEEK AND PRETTY MUCH
CENTERED OVER THE AREA THURSDAY INTO FRIDAY. NEW GUIDANCE COMING
IN IS A COUPLE OF DEGREES COOLER /TEMPS AND DEWPOINTS/ AND HAVE
BEGUN TRENDING THAT WAY. THIS HOWEVER IS A BIT OF A PROBLEM LATE
IN THE PERIOD AS A STRONG MID-LEVEL LOW CUTS OFF OVER THE DESERT
SOUTHWEST AND INDUCES SURFACE LOW PRESSURE FORMATION IN THE
NORTHWEST GULF. GULF MOISTURE STREAMS ACROSS THE SOUTHERN PLAINS
AND INTO THE SOUTHEAST LATE THURSDAY INTO THURSDAY NIGHT...AND
THERE IS SOME CONCERN THAT BRIEF COLLOCATION OF THE COLDER TEMPS
AND INCOMING MOISTURE MIGHT LEAD TO A RAIN/SNOW MIX OR A BRIEF
CHANGEOVER ESPECIALLY ACROSS NORTH GEORGIA LATE THURSDAY NIGHT AND
EARLY FRIDAY. HAVE ADDED THE BRIEF MIX TO THE GRIDS BUT WILL HAVE
TO REEVALUATE THROUGH THE PERIOD. GFS AND ECMWF IN BETTER
AGREEMENT ON THE LATE-WEEK SYSTEM...THOUGH GFS REMAINS A TAD
FASTER...BUT MOST OF THAT IS JUST BEYOND THE EXTENDED PERIOD.

TDP

&&

.AVIATION... 
18Z UPDATE...
EXPECTING VFR CONDITIONS TO PREVAIL THROUGH THIS TAF PERIOD... WITH 
MAINLY VARYING HIGH CLOUDS TONIGHT-EARLY SAT... THEN LOWERING TO MID 
LEVELS CIGS SOMETIME SAT AFTERNOON. EXPECT SOME PATCHY IFR/MVFR FOG 
AGAIN EARLY SAT MORNING UNTIL AROUND 13-14Z...BUT SHOULD NOT BE A 
FACTOR AT ATL. LIGHT EAST WINDS WILL PREVAIL TONIGHT AND EARLY 
SAT... THEN BECOME MORE SE SAT AFTERNOON. SPEEDS ON SAT 7KTS OR 
LESS. /39

//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS INTO TONIGHT.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          34  59  49  60 /   0  20  80  70 
ATLANTA         39  61  52  61 /   5  50  90  70 
BLAIRSVILLE     31  60  45  56 /   0  20  90  90 
CARTERSVILLE    33  59  48  60 /   5  50  90  80 
COLUMBUS        39  62  53  68 /  10  60  70  50 
GAINESVILLE     37  58  50  59 /   0  20  90  80 
MACON           35  63  51  70 /   5  30  50  40 
ROME            33  58  47  60 /   5  60  90  90 
PEACHTREE CITY  34  61  50  63 /   5  50  80  70 
VIDALIA         41  67  53  73 /   5  20  30  30 

&&

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

$$

SHORT TERM...39
LONG TERM....TDP
AVIATION...39

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