FXUS62 KFFC 170302 AFDFFC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 1102 PM EDT SUN MAR 16 2014 .UPDATE... LATEST SURFACE ANALYSIS INDICATES SURFACE LOW NOW EXTENDING FROM A ROME TO BIRMINGHAM LINE WITH A WARM FRONT EXTENDING THROUGH ATHENS AND COLUMBIA. SOME INDICATIONS OF A WEAK LOW BEGINNING TO FORM OFF THE SOUTH CAROLINA COAST WHICH WILL BE A BIG PLAYER FOR OUR WEATHER GOING FORWARD WRT HOW QUICKLY IT FORMS. SOUTH FLOW ALONG AND AHEAD OF LOW ALLOWED CLEARING SKIES TO DEVELOP LATE AS WELL AS AN ASSOCIATED AXIS OF INSTABILITY WHICH NOT ONLY INCREASED THE COVERAGE OF SHOWERS BUT ALSO PRODUCED ISOLATED THUNDERSTORMS IN THE VICINITY OF THE WARM FRONT. SPC SREF INDICATES SHORT TERM TRENDS WILL BE FOR THE LITTLE INSTABILITY THERE IS OUT THERE TO DIE OFF BUT A LITTLE CONCERNED ABOUT DEWPOINTS WHICH WERE SUPPOSED TO BE IN THE MID 50S ARE NOW IN THE LOWER 60S AND SURGING NORTHWARD. MODELS MAY NOT BE PICKING UP ON THE POTENTIAL INSTABILITY OUT THERE SO PLAN ON KEEPING ISOLATED THUNDER IN THE GRIDS FOR NOW. OTHERWISE...POPS MAY BE A LITTLE HIGH BUT AGAIN POTENTIAL IS THERE FOR ACTIVITY TO FILL IN SO AM HESITANT TO MAKE ANY SIGNIFICANT CHANGES AT THIS POINT. && DEESE && .PREV DISCUSSION... /ISSUED 808 PM EDT SUN MAR 16 2014/ PREV DISCUSSION... /ISSUED 333 PM EDT SUN MAR 16 2014/ SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... BAND OF HEAVIER PRECIPITATION SHIFTING EAST/SOUTH OF THE FORECAST AREA THIS AFTERNOON WITH A BIT OF A DRY SLOT IMPACTING THE MAJORITY OF THE FORECAST AREA INTO THE EVENING. HOWEVER...WITH THE UPPER TROUGH AXIS REMAINING WEST OF THE STATE THROUGH THE DAY MONDAY I HAVE RETAINED FAIRLY HIGH POPS THROUGH THE FORECAST PERIOD. STILL SOME HEAVY RAIN POTENTIAL IN THE FAR SOUTH/SOUTHEAST THIS EVENING UNTIL THE AXIS OF DEEPER MOISTURE SHIFTS EAST/SOUTH. STILL MARGINAL INSTABILITY FOR THUNDERSTORMS OUTSIDE OF THE WEDGE...BUT BETTER LOW-LEVEL AND MEDIUM DEPTH SHEAR IS ALREADY SHIFTING SOUTH AND EAST OF OUR FORECAST AREA. I WILL BE CARRYING SLIGHT CHANCE/CHANCE FOR THUNDER OUTSIDE OF THE WEDGE DOMINATED AREAS INTO THE EVENING. THE WEDGE SHOULD HOLD ON FROM THE METRO AREA NORTHEAST AND EAST...EVEN IN THE FACE OF THE APPROACHING SURFACE LOW. IF FACT MODELS ARE FORTIFYING THE WEDGE SOMEWHAT LATE IN THE PERIOD AS THE SURFACE LOW RE-DEVELOPS OFF THE SOUTH CAROLINA COAST. SOURCE AIRMASS FOR THE WEDGE IS RELATIVELY MILD SO WE SHOULD NOT SEE ANY EXTREME EFFECTS IN OUR NORTHEAST/EAST CENTRAL COUNTIES. ONLY A FEW MINOR HYDROLOGIC ISSUES HAVE CROPPED UP FROM TODAYS RAIN AND ADDITIONAL QPF TOTALS THROUGH MONDAY ARE MORE MODEST AS THE RICHER MOISTURE SHIFTS EAST AND PRECIPITATION BECOMES MORE SCATTERED IN NATURE. 20 LONG TERM /TUESDAY THROUGH SUNDAY/... HAVE MADE LITTLE CHANGE TO THE FORECAST AS LOOKS TO BE ON TRACK AND CANNOT JUSTIFY NOTABLE ADJUSTMENTS. PREVIOUS DISCUSSION FOLLOWS... BAKER PREV DISCUSSION... /ISSUED 401 AM EDT SUN MAR 16 2014/ LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... MODELS CONTINUE TO AGREE ON A STRONG SHORT WAVE TRAVERSING THE STATE MONDAY NIGHT...WHILE A SURFACE LOW PUSHES OFF THE SOUTHEAST GA COAST. THE DEPARTING SURFACE LOW WILL HELP STRENGTHEN A COLD WEDGE OF HIGH PRESSURE NOSING DOWN THE EASTERN APPALACHIANS... RESULTING IN A COOL... CLOUDY TUESDAY... WITH PATCHES OF OVERRUNNING LIGHT RAIN... ESPECIALLY ALONG THE EASTERN HALF OF THE STATE. THE UPPER DISTURBANCE PUSHES EAST TUESDAY AFTERNOON... BUT A MOIST SOUTHERLY MID LEVEL FLOW WILL CONTINUE TO OVERRUN THE COOL NORTHEAST SURFACE FLOW... WARRANTING A SLIGHT CHANCE OF RAIN ACROSS NORTH GA TUESDAY NIGHT. LONG RANGE MODELS CONTINUE TO SHOW A WEAK COLD FRONT POSSIBLY BRINGING A LOW CHANCE OF RAIN TO THE AREA WEDNESDAY-WEDNESDAY NIGHT WITH SOME DIFFERENCE IN TIMING. PREFER THE FASTER AND MORE PERSISTENT GFS FOR NOW WITH HIGH PRESSURE AND DRY CONDITIONS ON TAP FOR THURSDAY AND FRIDAY. ECMWF AND GFS SHOW ANOTHER COLD FRONT PUSHING INTO THE AREA ON SATURDAY. WILL SHOW A CHANCE OF SHOWERS ON SATURDAY. NO THUNDER IS EXPECTED AT THIS TIME WITH LACK OF INSTABILITY AND STRONG UPPER SUPPORT NOTED. 39 AVIATION... 00Z UPDATE... YET ANOTHER COMPLEX SCENARIO ACROSS THE TERMINALS THIS EVENING WITH WARM FRONT EXTENDING FROM COLUMBIA THROUGH NORTH GEORGIA INCLUDING THE ATL TERMINALS AND THEN INTO A SURFACE LOW OVER NORTHERN ALABAMA. ACTUALLY HAVE HAD SOME CLEARING OVER ALABAMA AND NOW THE DEVELOPMENT OF ISOLATED THUNDERSTORMS IN THE AREA. QUESTION BECOMES DOES THIS ACTIVITY SHIFT OVER OUR AREA OR DOES IT DISSIPATE AND LOW CIGS AND EAST WINDS OF WEDGE PREVAIL. GIVEN HOW CLOSE WE ARE TO SUNSET...EXPECT STORMS TO REMAIN WEST OF THE AREA AND LOW CIGS TO REMAIN IN PLACE FOR THE NORTHERN TERMINALS. WILL ALSO SEE A RETURN TO SOME LIGHT RAIN AS WELL. TO THE SOUTH...MORE PROBLEMATIC BUT ANTICIPATE PERIODS OF MVFR AND IFR AND THEN BECOMING ALL IFR DURING THE OVERNIGHT PERIOD. //ATL CONFIDENCE...00Z UPDATE... MEDIUM ON ALL ELEMENTS. DEESE && .PRELIMINARY POINT TEMPS/POPS... ATHENS 46 47 39 49 / 80 60 60 40 ATLANTA 50 54 42 55 / 60 60 50 20 BLAIRSVILLE 45 48 40 51 / 70 50 50 30 CARTERSVILLE 51 55 41 56 / 60 50 50 20 COLUMBUS 57 64 47 62 / 70 60 50 20 GAINESVILLE 45 45 40 51 / 70 50 60 40 MACON 55 62 44 56 / 90 70 60 30 ROME 50 53 41 57 / 60 50 50 20 PEACHTREE CITY 51 57 43 55 / 60 60 50 20 VIDALIA 58 62 47 58 / 90 80 70 40 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DEESE LONG TERM....41 AVIATION...DEESE
Posted on: Mon, 17 Mar 2014 03:03:16 +0000