FXUS62 KFFC 150757 AFDFFC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 357 AM EDT SAT MAR 15 2014 .SHORT TERM /TODAY THROUGH SUNDAY NIGHT/... ONE MORE BEAUTIFUL DAY IN STORE ACROSS THE AREA WITH INCREASING MID- AND HIGH-LEVEL CLOUDINESS. SEEING SOME LIGHT RAIN MOVE ACROSS THE CENTER OF THE FORECAST AREA THIS MORNING IN RESPONSE TO A WEAK SHORTWAVE TROUGH. AS WITH THE FORECAST YESTERDAY...THIS WAS REALLY ONLY DEPICTED ON THE ECMWF AND OF COURSE HI-RES CONVECTION-ALLOWING MODELS...SO DEFINITELY SEE REASON TO LEAN TOWARD THE ECMWF IN MASS FIELDS. FOR TODAY...SURFACE MOISTURE WILL INCREASE AND WITH TEMPERATURES A FEW DEGREES ABOVE SEASONAL NORMALS...MIGHT ACTUALLY FEEL KIND OF MUGGY OUT THERE ESPECIALLY THIS AFTERNOON. BUT AGAIN FOR THE MOST PART A REALLY NICE DAY. CONDITIONS GO DOWNHILL RAPIDLY AFTER MIDNIGHT TONIGHT AS A STRONG UPPER TROUGH PUSHES OUT OF THE ROCKIES INTO THE SOUTHERN PLAINS... SPREADING GULF MOISTURE ACROSS THE SOUTHERN PORTION OF THE COUNTRY. THE TROUGH DEEPENS THROUGH THE SHORT TERM WITH STRONG SOUTHWEST FLOW ALOFT IN THE SUBTROPICAL JET. GFS AND ECMWF ACTUALLY IN FAIRLY DECENT AGREEMENT ON MASS FIELDS WITH SIMILAR PLACEMENT OF SURFACE LOW AND DEPICTION OF DIABATICALLY ENHANCED CLASSICAL CAD DEVELOPING LATE ON SUNDAY AS SURFACE HIGH OVER THE GREAT LAKES BEGINS TO RIDGE DOWN THE EASTERN SEABOARD. MAIN DIFFERENCES ARE WITH THE STRENGTH OF THE WEDGE FRONT WHERE AS IS TYPICAL...GFS AND NAM SEEM TO HAVE A BETTER GRASP ON THE REALITY OF CAD THAN THE ECMWF. SO WHAT DOES ALL THIS MEAN...WELL...IT MEANS RAIN ON SUNDAY WITH MUCH COOLER HIGH TEMPS...ESPECIALLY IN NORTHEAST GEORGIA WHERE THE CAD WILL BE MORE FIRMLY ENTRENCHED. SEE HYDRO SECTION BELOW FOR MORE ON THE RAIN. OTHER ITEM OF CONCERN IS CHANCE FOR HIGH SHEAR/LOW CAPE CONVECTION ON SUNDAY. ALL SYNOPTIC GUIDANCE INDICATES SOME SORT OF QLCS/SQUALL LINE PUSHING ACROSS THE NORTHERN GULF COAST ON SUNDAY AND WITH WEDGE FRONT IN PLACE ACROSS OUR AREA...CANNOT RULE OUT THAT CONVECTION WILL SPREAD AS FAR NORTH AS THAT WEDGE FRONT. HAVE KEPT TREND OF SLIGHT TO CHANCE THUNDER ON SUNDAY WITH BEST CHANCES SUNDAY AFTERNOON ACROSS CENTRAL GEORGIA. SPC DAY2 OUTLOOK ONLY HAS SOUTHWEST ZONES IN GENERAL THUNDER BUT WITH MUCAPE BETWEEN 200-500 J/KG DEPENDING ON WHICH MODEL YOU BELIEVE...WITH EVEN UPWARDS OF 200 J/KG MLCAPE ON THE GFS...AND 50-60KT 0-6KM SHEAR AND 30-40KT 0-1KM SHEAR ACROSS CENTRAL GEORGIA /HIGHER VALUES NORTHEAST IN THE CAD/...SOME MINIMAL CONCERN IS THERE. SHERB PARAMETER SPREADS AN AREA GREATER THAN 1 /CRITICAL THRESHOLD/ ACROSS CENTRAL GEORGIA BETWEEN 18-00Z. EVEN HIRES SURFACE WIND FIELDS SEEM TO WANT TO PICK UP ON INCREASED WINDS ACROSS THIS SAME AREA. WITH THAT CANNOT RULE OUT AN ISOLATED SEVERE GUST IF A QLCS IS ABLE TO PUSH THROUGH. THAT SAID...WITH CONVECTION ALONG THE GULF COAST...THIS MAY CUT OFF SOME OF THE RAIN ACROSS OUR AREA INCLUDING POTENTIAL CONVECTION ACROSS CENTRAL GEORGIA. OBVIOUSLY STILL SOME UNCERTAINTY HERE SO WILL HAVE TO GET A BETTER HANDLE AS TO HOW THIS WILL PLAY OUT DURING THE NEXT FEW MODEL RUNS. TDP .LONG TERM /MONDAY THROUGH FRIDAY/... ECMWF AND GFS ARE IN FAIRLY GOOD AGREEMENT WITH BOTH SHOWING AN UPPER DISTURBANCE PUSHING A WEAK SURFACE LOW ACROSS PARTS OF CENTRAL AND SOUTH GEORGIA MONDAY AND MONDAY NIGHT. THE DRIVING UPPER DISTURBANCE DOES NOT PUSH EAST OF THE AREA UNTIL TUESDAY... SO WRAP AROUND MOISTURE AND PATCHES OF LIGHT RAIN MAY LINGER ON TUESDAY. AS THE SURFACE LOW APPROACHES ON MONDAY... MODELS SHOW A COOL WEDGE OF HIGH PRESSURE NOSING DOWN FROM THE NORTHEAST AND PROVIDING A STABLE AIR MASS OVER THE AREA MONDAY AND MONDAY NIGHT. THIS SUGGEST THE GREATER THUNDERSTORM THREAT WILL BE ACROSS SOUTH GEORGIA AND FLORIDA MONDAY-TUESDAY AS THE LOW PRESSURE SYSTEM MOVES ACROSS. HOWEVER... IF THE WARM FRONT IS ABLE TO ADVANCE INTO PARTS OF CENTRAL GEORGIA MONDAY AFTERNOON... ISOLATED THUNDERSTORMS MAY HAVE TO BE ADDED WITH LATER FORECAST. OTHERWISE... LONG RANGE MODELS SHOW A WEAK COLD FRONT POSSIBLY BRINGING A LOW CHANCE OF RAIN TO THE AREA BY MID WEEK... WITH THE GFS THE FASTEST AND SHOWING A FROPA ON WEDNESDAY... WHILE THE ECMWF SHOWS WEDNESDAY NIGHT-THURSDAY. BOTH ARE FAIRLY DRY WITH THIS SYSTEM... SO WILL ONLY SHOW A SLIGHT CHANCE OF SHOWERS ACROSS NORTH GA WEDNESDAY AND WEDNESDAY NIGHT FOR NOW. MODELS SHOW DRY HIGH PRESSURE SETTLING OVER THE DEEP SOUTH FOR THURSDAY AND FRIDAY. 39 && .HYDROLOGY... STORM TOTAL QPF REMAINS UNDER 2 INCHES SO FOR NOW AM NOT CONCERNED ABOUT WIDESPREAD HYDRO ISSUES THOUGH ISOLATED MINOR FLOODING CANNOT BE RULED OUT. COULD SEE ISOLATED HIGHER AMOUNTS BUT THEN AGAIN AS MENTIONED ABOVE...COULD ALSO SEE RAIN ACROSS NORTH GEORGIA CUT OFF BY CONVECTION ALONG THE GULF COAST WHICH WOULD DRASTICALLY REDUCE QPF TOTALS. MOST RAIN ACROSS NORTH GEORGIA PROGGED TO FALL BETWEEN 12-18Z SUNDAY WITH WIDESPREAD 0.5-0.75 INCHES DURING THAT 6-HOUR PERIOD. HEAVIER RAINFALL RATES CAN BE EXPECTED IN ANY CONVECTION THAT DEVELOPS BUT THAT WILL MAINLY BE LIMITED TO PORTIONS OF CENTRAL GEORGIA WHERE HIGHER QPFS ARE MORE EASILY HANDLED. TDP && .FIRE WEATHER... FUEL MOISTURES ARE VERY LOW ACROSS THE AREA BUT DEWPOINTS ARE ON THE INCREASE AHEAD OF THE NEXT SYSTEM...SO RH VALUES SHOULD REMAIN ABOVE CRITICAL LEVELS TODAY. NO OTHER FIRE WEATHER CONCERNS AT THIS TIME. TDP && .AVIATION... /ISSUED AT 136 AM EDT SAT MAR 15 2014/ 06Z UPDATE... VFR TODAY BUT WITH INCREASING LOW VFR CLOUDINESS. CONDITIONS RAPIDLY DETERIORATE AFTER 06Z SUNDAY WITH MVFR CIGS MOVING IN WITH -SHRA. SSW WINDS WILL VEER TO NEARLY W LATER THIS MORNING...BACK TO SW AND SSE JUST AFTER 00Z...REMAINING SE THROUGH THE END OF THE PERIOD. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON TIMING OF WIND SHIFTS AND MVFR CIGS. HIGH ON OCCURRENCE OF WIND SHIFTS AND MVFR CIGS. TDP && .PRELIMINARY POINT TEMPS/POPS... ATHENS 72 51 59 46 / 20 80 100 90 ATLANTA 69 52 61 49 / 20 100 100 70 BLAIRSVILLE 65 47 55 45 / 0 80 100 80 CARTERSVILLE 69 51 61 50 / 5 100 100 70 COLUMBUS 70 54 66 55 / 10 80 100 70 GAINESVILLE 67 51 55 46 / 5 90 100 80 MACON 72 52 66 55 / 5 70 100 90 ROME 69 51 62 50 / 5 100 100 60 PEACHTREE CITY 69 51 62 50 / 30 90 100 70 VIDALIA 74 54 69 58 / 0 50 100 100 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...TDP LONG TERM....39 AVIATION...TDP
Posted on: Sat, 15 Mar 2014 07:57:52 +0000
Trending Topics
Recently Viewed Topics
© 2015