637  
FXUS62 KFFC 031953  
AFDFFC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PEACHTREE CITY GA  
253 PM EST SAT DEC 3 2016  
 
   
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/
 
 
SHORT RANGE MODELS SHOW GOOD AGREEMENT WITH OVERALL WET PATTERN  
SETTLING IN OVER THE FORECAST AREA BY THIS EVENING AND PERSISTING  
THROUGH EARLY NEXT WEEK. IN THE SHORT TERM... AREAS OF MAINLY LIGHT  
RAIN CURRENTLY SEEN ON REGIONAL RADARS TO THE WEST WILL SPREAD INTO  
NORTH AND WEST CENTRAL GA AREAS BY THIS EVENING AS A WARM/MOIST MID  
LEVEL SOUTHERLY FLOW OVERRUNS A COOL EASTERLY FLOW NEAR THE SURFACE.  
THE STABLE LOWER LEVELS WILL GREATLY HINDER ANY THUNDERSTORM  
THREAT... SO WILL WORD FOR JUST RAIN/RAIN SHOWERS FOR NOW. WILL ALSO  
ADD SOME WORDING FOR PATCHY FOG AND DRIZZLE TONIGHT AS THE LOWER  
LEVELS BECOME SATURATED AND CLOUDS LOWER. AS FOR RAINFALL... STRONG  
ISENTROPIC LIFT WILL PRODUCE WIDESPREAD LIGHT TO MODERATE RAINS  
ACROSS THE AREA THROUGH THE PERIOD. A SERIES OF DISTURBANCES  
EMBEDDED IN THE WESTERLY FLOW ALOFT WILL ENHANCE RAINFALL  
INTENSITIES AT TIMES... MAINLY SUNDAY AND SUNDAY NIGHT... AND LATEST  
MODEL RUNS ARE SUGGESTING THE HEAVIEST RAINFALL AXIS MAY SET UP  
SOMEWHERE NEAR THE I-85 CORRIDOR WHERE AROUND 2-3 INCHES OF RAINFALL  
COULD BE OBSERVED THROUGH SUNDAY NIGHT. IF THIS AXIS SETS UP ACROSS  
ATLANTA METRO AREA... THESE RAINFALL AMOUNTS COULD PUSH SEVERAL OF  
THE TYPICAL FLOOD PRONE CREEKS TO AT LEAST BANKFULL BY SUNDAY  
EVENING. WILL HAVE TO CLOSELY MONITOR THE POTENTIAL FOR MINOR...  
SHORT LIVED FLOOD PROBLEMS ACROSS MAYBE PARTS OF NORTH GA OVER THE  
NEXT SEVERAL DAYS WHERE HEAVIER RAINS FELL EARLIER IN THE WEEK. WILL  
ISSUE A HYDROLOGIC OUTLOOK /ATLESFFFC/ TO ADDRESS THE POTENTIAL  
HEAVY RAIN AND FLOOD THREAT IN MORE DETAIL.  
 
THE CLOUDS AND COOL RAINS WILL PROBABLY HOLD TEMPS IN THE 40S FOR  
MOST AREAS BOTH DAY AND NIGHT... SO DON'T EXPECT MUCH DIURNAL CHANGE  
WITH TEMPS AT THIS TIME... EXCEPT FOR THOSE AREAS ALONG THE FAR  
SOUTHERN REACHES WHERE THE WEDGE FRONT MAY BE ABLE TO CREEP NORTHWARD  
FAR ENOUGH TO ALLOW THOSE AREAS TO SEE TEMPS CLIMB INTO THE 50S BY  
SUNDAY AFTERNOON... BUT JUST BRIEFLY. DID NOT STRAY FAR FROM OVERALL  
MOS GUIDANCES FOR POPS AND TEMPS THROUGH THE PERIOD.  
 
39  
 
   
LONG TERM /MONDAY THROUGH SATURDAY/
 
 
FORECAST IS ON TRACK WITH ONLY MINOR CHANGES MADE TO THIS UPDATE.  
TWO ROUNDS OF RAIN ARE EXPECTED EARLY SUNDAY THROUGH SUNDAY NIGHT  
AND THEN AGAIN MONDAY NIGHT INTO TUESDAY AS THE MAIN LOW TO THE  
WEST MOVES NORTHWARD. STORM TOTAL RAINFALL THROUGH TUESDAY IS  
STILL EXPECTED TO BE AROUND 2 TO 4 INCHES. GIVEN THE RAINFALL  
EXPECTED, WE MAY SEE LOCALIZED FLOODING ACROSS URBAN AREAS IF  
TRAINING SETS UP ACROSS METRO ATLANTA. TO THIS END, MINOR  
FLOODING OF THE TYPICAL FLOOD PRONE CREEKS IS POSSIBLE, ESPECIALLY  
IF WE OBSERVE HIGH RAINFALL RATES OVER A SHORT PERIOD OF TIME.  
THUNDERSTORMS WILL BE LIMITED GIVEN THE WARM FRONT MAY ACTUALLY  
STAY TO OUR SOUTH OR JUST ACROSS CENTRAL GEORGIA MONDAY NIGHT INTO  
TUESDAY.  
 
MODELS ARE COMING INTO BETTER AGREEMENT IN TERMS OF TIMING OF THE  
NEXT FRONT THURSDAY INTO FRIDAY WITH BELOW NORMAL TEMPERATURES  
EXPECTED BY THE END OF THE WORK-WEEK.  
 
26  
 
PREV DISCUSSION... /ISSUED 325 AM EST SAT DEC 3 2016/  
 
MEDIUM RANGE MODELS REMAIN CONSISTENT WITH RECENT RUNS AND IN  
FAIRLY GOOD AGREEMENT THROUGH THE MAJORITY OF THE PERIOD. WET  
START TO THE PERIOD AS THE REGION REMAINS UNDER STRONG  
SOUTHWESTERLY UPPER-LEVEL FLOW. MODELS STILL FLIP-FLOPPING A BIT  
CONCERNING THE AMOUNT AND DISTRIBUTION OF ANY INSTABILITY  
AVAILABLE WITH THE MAIN SHORT WAVE AS IT SWEEPS THROUGH OVERNIGHT  
MONDAY INTO TUESDAY. I STILL THINK THERE WILL BE SUFFICIENT  
ELEVATED INSTABILITY ACROSS THE WEST AND SOUTH FOR AT LEAST A  
SLIGHT CHANCE OF THUNDER MONDAY NIGHT AND TUESDAY, MAINLY ACROSS  
THE WEST/SOUTH MONDAY NIGHT AND ACROSS THE SOUTH TUESDAY. STILL  
SEEING DECENT SHEAR IN THE MID-LEVELS BUT THE LOWER-LEVEL SHEAR IS  
NOT AS IMPRESSIVE. OVERALL SEVERE THREAT LOOKS MARGINAL AT BEST AT  
THIS TIME. LARGE-SCALE UPPER FLOW REMAINS MORE WEST TO SOUTHWEST  
BEHIND THE INITIAL SYSTEM KEEPING THE BETTER COLD AIR NORTH AND  
WEST OF THE STATE UNTIL THURSDAY AND INTO NEXT WEEKEND AS THE  
LARGE, DEEP UPPER TROUGH SETTLES INTO THE EASTERN SEABOARD.  
 
20  
 

 
   
HYDROLOGY
 
 
A MOIST AND UNSETTLED PATTERN IS EXPECTED ACROSS THE FORECAST AREA  
THROUGH TUESDAY. PERIODS OF MODERATE TO HEAVY RAINFALL ARE  
EXPECTED AS A SERIES OF IMPULSES CROSS THE AREA SUNDAY AND A MORE  
ROBUST SURFACE LOW TO THE WEST LIFTS NORTH MONDAY AFTERNOON  
THROUGH TUESDAY. THE GREATEST CHANCE OF RAINFALL WILL BE SUNDAY  
INTO SUNDAY NIGHT AND THEN ANOTHER ROUND MONDAY NIGHT INTO  
TUESDAY. STORM TOTAL RAINFALL OF 2 TO 4 INCHES IS EXPECTED.  
 
ISOLATED FLASH FLOODING WILL BE POSSIBLE IF THE HEAVY RAIN  
REPEATEDLY MOVES OVER THE SAME AREA OR IF HEAVY DOWNPOURS RESULT  
IN HIGH RAINFALL AMOUNTS OVER A SHORT PERIOD OF TIME. GIVEN LOSS  
OF LEAVES OVER THE LAST COUPLE OF WEEKS, STORM DRAINS AND DITCHES  
MAY QUICKLY CLOG WITH DEBRIS AND CAUSE STREET FLOODING AND ROAD  
PONDING.  
 
MINOR FLOODING OF SOME OF THE TYPICAL FLOOD PRONE CREEKS IS  
POSSIBLE, ESPECIALLY IF TRAINING SETS UP ANYWHERE ALONG AND NORTH  
OF THE I-85 CORRIDOR.  
 

 
 
AVIATION...  
18Z UPDATE...  
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH LATE TONIGHT... WITH  
MAINLY MID AND HIGH LEVEL CLOUDS. MODELS AGREE ON MVFR CIGS SETTLING  
IN OVER MOST TAF SITES BY 12Z SUN ALONG WITH PREVAILING -RADZ.  
INCREASING RAIN INTENSITY SHOULD HELP LOWER CIGS TO IFR LEVELS BY 18-  
20Z SUN AND THESE LOW CIGS WILL PERSIST THROUGH SUN NIGHT... WITH  
GRADUAL IMPROVEMENT EXPECTED ON MON. NE TO EAST WINDS WILL PREVAIL  
THROUGH THE TAF PERIOD. WIND SPEEDS WILL INCREASE TOWARD 12Z SUN  
WITH OCCASIONAL GUSTS TO AROUND 18-20KTS EXPECTED ON SUN.  
 
//ATL CONFIDENCE...18Z UPDATE...  
MEDIUM ON TIMING OF RADZ TONIGHT.  
MEDIUM ON MVFR AND IFR CIGS LATE TONIGHT AND SUNDAY.  
HIGH ON REMAINING ELEMENTS.  
 
39  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
ATHENS 43 47 43 53 / 60 90 80 70  
ATLANTA 44 49 45 54 / 80 90 80 80  
BLAIRSVILLE 38 45 41 54 / 90 90 80 70  
CARTERSVILLE 43 48 44 54 / 90 90 80 80  
COLUMBUS 46 56 50 61 / 60 80 70 70  
GAINESVILLE 43 45 42 53 / 70 90 90 70  
MACON 42 55 49 59 / 40 70 70 70  
ROME 42 48 45 55 / 100 100 80 70  
PEACHTREE CITY 42 49 44 55 / 70 90 80 80  
VIDALIA 46 65 57 66 / 20 40 60 70  
 

 
   
FFC WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...39  
LONG TERM....26  
AVIATION...39  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab GA Page Main Text Page