####018004300#### FXUS63 KILX 091115 AFDILX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 515 AM CST MON FEB 9 2009 .DISCUSSION... ISSUED 307 AM CST MON FEB 9 2009 VERY LITTLE IN THE WAY OF CHANGE IN THE FORECAST THIS MORNING. RATHER AGGRESSIVE WAVE KICKING OUT OF THE SRN PLAINS THIS MORNING...PUSHING CLOUDS INTO CENTRAL ILLINOIS WELL AHEAD OF THE NEXT ROUND OF PRECIPITATION. S/SERLY WINDS AT THE SFC PROVIDING PLENTY OF LLVL MOISTURE...AND VISIBILITIES ARE STRUGGLING THIS MORNING...KEPT FROM REALLY GETTING OUT OF CONTROL BY THE WEAK WAA AT THE SFC THAT IS ACCOMPANYING THE WARMER AIR. PLENTY OF MOISTURE IN THE BOUNDARY LAYER FOR THE RAIN TO DEVELOP LATER...WHICH IS THE FIRST ISSUE FOR THE FORECAST...FOLLOWED BY THE NEXT SYSTEM TOMORROW NIGHT AND INTO WEDNESDAY. MODELS ARE DOING RATHER WELL...AND HAVE KEPT TO A MORE NAM/ECMWF SOLUTION. PROBLEM FOR THE MODEL RUNS IS STILL TIMING...FLIPPING BETWEEN EARLIER AND LATER STILL. THIS PARTICULAR RUN IS MUCH QUICKER WITH THE LATER SYSTEM... AND HAVE ADJUSTED THE FORECAST AS SUCH SINCE IT WAS NOT FAR OFF FROM THE 12Z RUNS. SHORT TERM...TODAY AND TOMORROW... ONSET OF THE PRECIP TODAY IS THE FIRST MAJOR ISSUE WITH THE FORECAST. THE GFS IS A BIT MORE DIFFUSE WITH THE MORNING PRECIP AND BRINGS IT INTO WESTERN ILLINOIS BEFORE 18Z. THE NAM/WRF DELAYS IT BY ABOUT 6 HOURS...AND WOULD NORMALLY BE MORE INCLINED TO FOLLOW THE LATER AND MORE CONSERVATIVE NAM/WRF...EXCEPT THAT THE ECMWF HAS PRECIP WELL IN BEFORE THAT...MORE ASSOCIATED WITH THE GENERAL TREND OF THE FA THAT IS CURRENTLY GOING ON. THOUGH THE WIND HAS AN EASTERLY COMPONENT TO IT... IT SEEMS TO BE FEEDING WARMER AND MOISTER AIR INTO THE REGION INSTEAD OF INHIBITING. NOT TO MENTION THAT PLENTY OF LOW LEVEL CLOUDS ARE ALREADY IN PLACE. SEEMS TO ERR ON THE SIDE OF A SOONER START TO THE PRECIP MIGHT BE WARRANTED... IF ONLY IN THE FAR WEST. AS A RESULT... LEFT THE LIGHT POPS IN THERE BEFORE NOON. BETTER CHANCES THIS AFTERNOON AND TONIGHT...WITH THUNDER IN THE FORECAST WITH THE MUCH WARMER TEMPS AND BETTER INSTABILITY. MODELS HAVE SPED UP THIS SYSTEM AS WELL...PUSHING THE MAJORITY OF THE SHOWERS THROUGH BY MIDNIGHT. GRIDS REFLECT AS MUCH WITH ONLY SOME LINGERING SHOWERS IN THE SE AFTER 06Z. TOMORROW A BRIEF RESPITE FOR THE MORNING...THEN ANOTHER SYSTEM MOVES THROUGH CENTRAL ILLINOIS...WITH THE SFC LOW VERY MUCH IN THEN NEIGHBORHOOD...TRACKING THROUGH THE CWA. WHEREAS SOME WAA ACTIVITY WILL START IN THE EVENING HOURS IN THE SW...THE BEST CHANCES SHOULD BE AFTER MIDNIGHT FOR THE REST OF THE FA...AND INTO WED MORNING. LONG TERM...WEDNESDAY THROUGH FRIDAY... RAIN AND THUNDER THROUGH WEDNESDAY AGAIN...COMING TO AN END WED NIGHT. FORECAST FOR SFC TEMPS TO DROP BELOW FREEZING LATE WED NIGHT/THURSDAY MORNING. WITH MODELS ACCELERATING THE EXIT OF PRECIP FROM THIS SYSTEM... AM A LITTLE HESITANT TO PUT IN TOO MUCH OF THE ACCUMULATING SNOW THAT HPC HAS BEEN HINTING FOR. NOT JUST YET. WANT TO GET A BETTER GRIP ON THE EXIT OF THE STORM BEFORE THE ACCUMULATIONS MAKE THE FORECAST. THURSDAY SLOWS BACK DOWN A BIT BEFORE YET ANOTHER LOW MOVES OUT OF THE SW AGAIN FRIDAY EVENING. HJS && .AVIATION... ISSUED 515 AM CST MON FEB 9 2009 WARM FNT FM CNTL MO INTO SRN IL WL MOVE NWD AND BE N OF THE CNTL IL TERMINALS BY 18Z. INITIAL MVFR CIGS AND/OR VSBYS WL IMPROVE AS THE WARM FNT PASSES AND VFR CONDS WL THEN PREVAIL...ALTHOUGH A DENSE MID/HI LVL CIG WILL CONT. STG SLY SFC WNDS WL BE COMMON WITHIN THE WARM SECTOR WITH SUSTAINED SPEEDS 20-25 KT AND GUSTS TO 35 KT. A SHARP UPR SHORTWAVE NOW OVR THE SRN PLAINS WL MOVE RAPIDLY NEWD TDY WITH SHWRS/TSTMS INCRSG AS IT APCHS. EXPECT ABT A 4HR PD OF PCPN FOR ANY GIVEN TERMINAL...BEGINNING AT SPI AROUND 22Z AND ADVANCING TO CMI BY 00Z TUE. ALTHOUGH THUNDER WL NOT BE AS WIDESPREAD AS THE RAIN...THE EXPECTED COVERAGE JUSTIFIES A TEMPO GROUP FOR TS. AFTER THE PCPN ENDS...THERE SHOULD BE ANOTHER COUPLE HRS OF MVFR CIGS BEFORE THE LOW CLDS CLR OUT AFT 06Z TUE...ALTHOUGH SLY SFC WNDS AROUND 15 KT WILL CONT THRU THE END OF THE TAF PD. 04 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ####018007230#### FXUS64 KMEG 091117 AFDMEG AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 517 AM CST MON FEB 9 2009 ...SEVERE THUNDERSTORMS AND HIGH WINDS EXPECTED LATE TUESDAY AFTERNOON THROUGH MIDDAY WEDNESDAY ACROSS THE MIDSOUTH... .DISCUSSION... A WINDY/STORMY WEATHER PATTERN CAN BE EXPECTED TODAY THROUGH WEDNESDAY. BIGGEST CHALLENGES ARE SEVERE THUNDERSTORMS AND WIND POTENTIAL DURING THIS TIME FRAME. LATEST MODELS WERE IN GOOD GENERAL AGREEMENT FOR THE NEXT SEVERAL DAYS WITH ONLY MINOR DIFFERENCES IN DETAIL. THE 00Z GFS MODEL SEEMED TO BE PERFORMING BETTER THAN MOST OTHER MODELS...THOUGH ALSO LIKED THE 00Z ECMWF MODEL AS WELL. AT 5 AM CST ACROSS THE FORECAST AREA...DRY AND PARTLY TO MOSTLY CLOUDY CONDITIONS WERE OCCURRING WITH HIGH THIN CIRRUS MOVING OVERHEAD. TEMPERATURES WERE WELL ABOVE NORMAL...RANGING FROM 47 AT LEXINGTON TN TO 56 AT MEMPHIS TN. A LOW PRESSURE DISTURBANCE OVER WESTERN OKLAHOMA AND NORTH TEXAS WAS QUICKLY MOVING NORTHEAST AND APPROACHING THE AREA. TODAY WILL BE WINDY AND WARM DAY. INCREASED WIND SPEEDS IN WIND ADVISORY...PARTICULARLY OVER NE AR AND MO BOOTHEEL WHERE GUSTS MAY APPROACH 50 MPH THIS AFTERNOON AS PRESSURE GRADIENT TIGHTENS AHEAD OF THE LOW PRESSURE DISTURBANCE. WOULD NOT BE SURPRISED IF ADVISORY NEEDED TO BE EXPANDED A BIT FARTHER EAST. SEE NO REASON HIGHS WILL NOT REACH THE LOWER TO MID 70S ACROSS THE AREA WITH EXCELLENT MIXING AND ABUNDANT MORNING SUN. RAIN CHANCES WILL INCREASE THIS AFTERNOON WEST OF INTERSTATE 55 AS THE LOW PRESSURE SYSTEM APPROACHES. A NARROW BAND OF SHOWERS AND PERHAPS THUNDERSTORMS MAY OCCUR ALONG IT. THERE IS THE POSSIBILITY A COLD POOL MAY DEVELOP WITH THE BAND OF SHOWERS/STORMS AND PRODUCE SOME ADDITIONAL GUSTY WINDS...BUT THESE SHOULD REMAIN SEVERE LIMITS...LESS THAN 58 MPH. PREFERRED THE 00Z GFS MODEL/MAVMOS FOR RAIN CHANCES THIS AFTERNOON. TONIGHT...RAIN CHANCES WILL INCREASE ACROSS MUCH OF THE AREA AS THE DISTURBANCE LEAVES A LOW LEVEL MOISTURE CONVERGENCE BOUNDARY BEHIND...ACROSS THE AREA. KEPT HIGH RAIN CHANCES OVER MUCH OF THE AREA...ABOVE 50 PERCENT...FOR SHOWERS AND PERHAPS A RUMBLE OR TWO OF THUNDER. NO SEVERE WEATHER IS EXPECTED WITH WEAK INSTABILITY AND WEAKENING WINDS. RAINFALL OF 0.10 UP TO 0.50 INCH IS POSSIBLE. MOIST CONDITIONS WILL PREVAIL ALONG WITH MILD TEMPERATURES IN THE MID TO UPPER 50S FOR LOWS. TUESDAY MORNING THROUGH EARLY AFTERNOON...THE MOISTURE CONVERGENCE BOUNDARY WILL REMAIN OVER THE AREA...PROBABLY NEAR OR JUST SOUTH OF INTERSTATE 40...SO SCATTERED SHOWERS CAN BE EXPECTED ALONG IT. MOSTLY CLOUDY SKIES WILL PREVAIL WITH TEMPERATURES WARMING INTO LOWER 70S. LATE TUESDAY AFTERNOON AND TUESDAY NIGHT...SEVERE POTENTIAL WILL INCREASE WEST OF A PARIS TN TO OXFORD MS LINE...PARTICULARLY WEST OF THE MS RIVER. NOW MORE CONCERNED ABOUT TORNADO POTENTIAL AS LATEST MODELS IN GOOD AGREEMENT ON STORMS DEVELOPING ON THE LEFTOVER MOISTURE BOUNDARY WHICH DEVELOPS INTO A WARM FRONT. THIS WARM FRONT LIFTS NORTH DURING THE EVENING HOURS...ALLOWING MUCH OF THE AREA TO GET INTO THE WARM SECTOR. THERE MAY BE AN ENHANCED RISK AREA ACROSS NORTHEAST AR AND MO BOOTHEEL BETWEEN 3 PM TUESDAY AND 6 AM WEDNESDAY WHERE SUPERCELLS MAY DEVELOP NEAR THE NORTHWARD ADVANCING WARM FRONT AND AHEAD OF THE DEVELOPING SQUALL LINE/COLD FRONT. IN THIS AREA...INSTABILITY WILL BE BEST...LIFTED INDICES -2 TO -4...SBCAPES 300-800 J/KG...PRESSURE/HEIGHT FALLS WILL BE GREATEST...AND BEST DYNAMICS WITH HIGHEST SHEAR AND HELICITY WILL BE. A FEW TORNADOES...DAMAGING WINDS...AND HAIL WOULD BE THE MAIN HAZARDS. CANNOT RULE OUT HEAVY RAINFALL OF 1 TO 2 INCHES AS WELL. WILL MONITOR TO SEE IF THIS ENHANCED RISK OCCURS OVER NE AR AND MO BOOTHEEL. ACROSS THE REST OF THE MIDSOUTH TUESDAY NIGHT...WINDY AND WARM CONDITIONS WILL PREVAIL WITH MOST SHOWERS AND STORMS MAINLY STAYING NE OF MEMPHIS NEAR THE WARM FRONT AS MID LEVEL CAPPING SHOULD LIMIT THE NUMBER OF STORMS. WINDS WILL INCREASE THROUGH THE NIGHT AND EXCEED WIND ADVISORY CRITERIA. WEDNESDAY MORNING...THE MAIN SQUALL LINE/FRONT WILL QUICKLY MOVE THROUGH THE AREA FROM EASTERN AR AROUND 6 AM TO THE MS/AL AND TN RIVER BY NOON CST. WIDESPREAD DAMAGING WINDS OF 60 MPH APPEAR LIKELY ALONG THE FRONT/SQUALL LINE. INTERESTINGLY...THE STRONGEST WINDS MAY ACTUALLY BE AHEAD AND JUST BEHIND THE SQUALL LINE/FRONT WITH A STRONG PRESSURE GRADIENT IN PLACE. TORNADOES APPEAR TO BE LESS LIKELY ALONG THE ACTUAL SQUALL LINE AS MOISTURE DEPTH WILL BE LIMITED AS DRY SLOTTING WILL BE OCCURRING ALOFT. WINDY CONDITIONS WILL PREVAIL...EVEN BEHIND THE SQUALL LINE/FRONT...SO WIND ADVISORIES WILL BE NEEDED. BY WEDNESDAY AFTERNOON...THE SEVERE WEATHER AND HIGH WIND THREAT WILL DIMINISH AS THE LOW PRESSURE SYSTEM QUICKLY DEPARTS. WINDS WILL SLOWLY DIMINISH AND SKIES WILL CLEAR SOME...ESPECIALLY SOUTH WHERE A MID LEVEL DRY SLOT WILL BE. THERE IS A SMALL CHANCE THAT A FEW SHOWERS/THUNDERSTORMS MAY DEVELOP UNDER THE UPPER LEVEL TROUGH/LOW NORTH OF INTERSTATE 40 WHICH COULD PRODUCE SMALL HAIL. CONFIDENCE OF THIS REDEVELOPMENT APPEARS LOW. THURSDAY THROUGH SUNDAY...AN ACTIVE/WETTER PATTERN APPEARS TO BE SHAPING UP WITH THE SUBTROPICAL JET AND DEEP MOISTURE NEARBY. A BRIEF DRY AND COOLER DAY CAN BE EXPECTED THURSDAY BEFORE RAIN CHANCES INCREASE FRIDAY. ANOTHER SYSTEM MAY ARRIVE ON SUNDAY. NOT EXPECTING ANY SEVERE WEATHER DURING THIS TIME FRAME AT THIS TIME. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL. MBS && .AVIATION... 06Z TAFS MID/HIGH LEVEL CLOUDS OVERSPREADING TAF SITES AS LOW NEAR THE TEXAS PANHANDLE MOVES NORTHEAST INTO THE CENTRAL PLAINS INTO MONDAY. SOUTHEAST WINDS WILL INCREASE TO AROUND 10-12 KTS TOWARDS SUNRISE AND VEER TO THE SOUTH LATE MONDAY MORNING AFTER 16Z WITH SUSTAINED WINDS BETWEEN 15 TO 20 KTS AND GUSTS BETWEEN 25 TO 30 KTS CONTINUING AT LEAST THROUGH 10/00Z. RAIN SHOWERS MAY BEGIN AT JBR AS EARLY AS 21Z WITH BEST CHANCES OF RAIN SHOWERS HOLDING OFF UNTIL AFTER 00Z AT JBR. RAIN CHANCES AT MKL/MEM NOT EXPECTED TO ARRIVE UNTIL AFTER 04-05Z. VFR CEILINGS EXPECTED AT ALL SITES THROUGH AT LEAST 00Z BUT WILL GRADUALLY LOWER TO MVFR CONDITIONS AFTER 00Z AT JBR AND 04Z AT MEM. CJC && .PRELIMINARY POINT TEMPS/POPS... MEM 74 58 72 60 / 40 80 70 90 MKL 73 57 71 60 / 10 70 70 70 JBR 71 55 71 57 / 60 70 60 90 TUP 74 57 74 60 / 10 40 50 50 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR- MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT. MS...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS AFTERNOON FOR COAHOMA-DESOTO-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA- YALOBUSHA. TN...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS AFTERNOON FOR DYER-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON. && $$