000 FXUS63 KIND 100843 AFDIND AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 340 AM EST FRI FEB 10 2012 .UPDATE... SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... AN UPPER TROUGH MOVING EAST ACROSS THE CENTRAL AND SOUTHERN MISSISSIPPI VALLEY WILL SPREAD LIGHT PRECIP INTO OUR REGION BY AFTERNOON AS AN ARCTIC COLD FRONT OVER THE UPPER MIDWEST MOVES ACROSS OUR REGION LATE TODAY AND EARLY TONIGHT. ON SATURDAY A COLD FLOW OF ARCTIC AIR WILL BE ACROSS OUR REGION. SOME LAKE EFFECT FLURRIES POSSIBLE MAINLY NORTH AND EAST. HIGH PRESSURE OVER THE NORTHERN THIS WEEKEND WILL MOVE ACROSS OUR REGION LATE SUNDAY AND EARLY MONDAY. THE COMBINATION OF WARM ADVECTION AND AN UPPER LEVEL DISTURBANCE WILL BRING PRECIP ACROSS OUR REGION BY LATE MONDAY INTO TUESDAY. FARTHER INTO THE EXTENDED...SOME MODELS INDICATE ANOTHER WEAK DISTURBANCE MAY AFFECT US BY THURSDAY. && .NEAR TERM /TODAY/... MAIN FOCUS WILL BE TIMING OF PRECIP...PRECIP TYPE AND IF ANY SNOW ACCUMULATIONS OCCUR TODAY. RADAR AND SURFACE OBSERVATIONS INDICATE RAIN HAS SPREAD AS FAR EAST AS SOUTHWEST MISSOURI AND WESTERN ARKANSAS. FOR OUR AREA I DOUBT MUCH OF ANYTHING WILL OCCUR BEFORE 15Z AND EVEN AT 18Z THERE WILL BE NO MORE THAN A SLIGHT CHANCE FROM INDY NORTH AND EAST. HOWEVER BY AFTERNOON HIGH PRECIP CHANCES WILL BE THE RULE ALL AREAS. HOWEVER PRECIP AMOUNTS WILL BE LIGHT. WITH THE EXCEPTION OF THE BOUNDARY LAYER...MODEL SOUNDINGS INDICATE SNOW. MODELS INDICATE A PRETTY GOOD WARM NOSE PUSHING INTO OUR REGION AHEAD OF THE COLD FRONT AND 1000-850 MB THICKNESS APPROACH 1300 METERS OVER MUCH OF OUR AREA THIS AFTERNOON. AS FAR AS PRECIP TYPE RELIED HEAVILY ON BUFKIT SOUNDINGS AND SREF PRECIP TYPE PROBABILITIES. THESE SEEM TO INDICATE MIXED OR EVEN ALL RAIN IN SOME AREAS OVER WESTERN INDIANA AND MOSTLY SNOW OVER FAR EASTERN SECTIONS. WILL GO WITH MOSTLY SNOW FROM INDY NORTH AND EAST AS NAM AND GFS BUFKIT AS WELL AS SREF PROBABILITIES LEAN THAT WAY. SINCE TEMPERATURES WILL BE ABOVE FREEZING DURING THE DAY TIME HOURS...ANY SNOW IMPACT WILL NOT BE THAT GREAT UNTIL THIS EVENING. BUT THEN THINGS WILL GO DOWN HILL DURING THE EVENING HOURS AS TEMPERATURES FALL AND LIGHT PRECIP CONTINUES TO OCCUR. AS FAR AS TEMPERATURES ARE CONCERNED WILL TREND TOWARDS COOLER MET NUMBERS AS WEATHER DEPICTION SHOWS LOTS OF CLOUDS UPSTREAM. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... COLD FRONT WILL BE MOVING THROUGH THIS EVENING AND MODELS HAVE TRENDED A LITTLE SLOWER IN ENDING PRECIP. MOST OF THIS WILL OCCUR BETWEEN 00Z AND 06Z AND SHOULD BE PRIMARILY ALL SNOW. WITH TEMPERATURES DROPPING WELL BELOW FREEZING AND WINDS INCREASING...THERE SHOULD BE SOME ISSUES WITH SLIPPERY ROADS TONIGHT. WILL CONTINUE SPECIAL WEATHER STATEMENT ON THIS. TOTAL SNOW AMOUNTS BY MIDNIGHT TONIGHT WILL RANGE FROM ABOUT A HALF INCH OVER WEST AND SOUTHWEST SECTIONS TO ABOUT AN INCH AND A HALF IN OUR EAST. ON SATURDAY...THERE MAY BE SOME LAKE ENHANCEMENT...BUT MOST OF THIS WILL BE LITTLE MORE THAN FLURRIES ACROSS OUR REGION AND AREA WILL SHIFT SLOWLY EAST DURING THE DAY AS FLOW BECOMES MORE WESTERLY. FINALLY MOSTLY CLEAR WEATHER WILL BE THE RULE SATURDAY NIGHT...SUNDAY AND MOST OF SUNDAY NIGHT. BUT WITH SOME CLOUDS SPREADING IN TOWARDS DAYBREAK MONDAY. WENT CLOSE TO A MAV/MET BLEND ON TEMPERATURES MOST PERIODS. BUT THEY MAY BE TAD WARMER ACROSS OUR NORTHWEST LATE TONIGHT WHERE SOME LAKE EFFECT CLOUDS ARE LIKELY TO OCCUR. WINDS GUSTS OF 25 TO 30 MPH ARE POSSIBLE TONIGHT AND SATURDAY AS PRESSURE GRADIENT SHARPENS ACROSS OUR REGION. && .LONG TERM /MONDAY THROUGH THURSDAY/... FORECAST FOCUS IN THE LONG TERM IS ON POTENTIAL FOR SNOW MONDAY THROUGH TUESDAY. MODELS ARE IN GOOD AGREEMENT EARLY AND THEN DIVERGE BY WEDNESDAY/THURSDAY. FOR TEMPERATURES THOUGHT THE ALLBLEND INITIALIZATION CAPTURED THINGS WELL AND MADE NO ADJUSTMENTS. THIS YIELDED TEMPERATURES NEAR AVERAGE AT THE BEGINNING OF THE LONG TERM INCREASING TO ABOVE AVERAGE FOR THE MIDDLE THROUGH THE END OF THE WEEK. FOR POPS DID MAKE SOME ADJUSTMENTS TO ALLBLEND BASED ON MODEL AGREEMENT OR LACK THEREOF. MONDAY HIGH PRESSURE WILL BE OVER THE AREA TO START THE DAY...BUT ECMWF/GFS/GEM ARE SHOWING UPPER FORCING ARRIVING BY MONDAY AFTERNOON AHEAD OF UPPER WAVE. THE MAJORITY OF THIS FORCING WILL MOVE THROUGH THE AREA MONDAY NIGHT...AND WITH GOOD AGREEMENT FROM THESE MODELS ON POSITION OF FORCING AND TIMING AS WELL AS AGREEMENT FROM NEIGHBORING OFFICES HAVE INCREASED POPS FROM CHANCE TO LOW END LIKELY. PRECIPITATION SHOULD MOVE OUT FROM WEST TO EAST ON TUESDAY BUT MAY NOT BE FAST ENOUGH TO BE OUT BY THE AFTERNOON SO MAINTAINED SLIGHT CHANCE IN THE WEST TO VERY LOW CHANCE POPS IN THE EAST. FOR PRECIPITATION TYPE SNOW WILL BE THE RULE FROM MONDAY AFTERNOON THROUGH MONDAY NIGHT. TUESDAY MORNING COULD SEE SOME RAIN MIX IN AND BY TUESDAY AFTERNOON THE SOUTH COULD SEE LIGHT RAIN IF PRECIPITATION HASN/T CLEARED OUT. UPPER RIDGING SHOULD BE IN PLACE FOR TUESDAY NIGHT AND WEDNESDAY SO WENT DRY THEN. LOW PRECIPITATION CHANCES MOVE BACK IN WEDNESDAY NIGHT WITH THE POSSIBILITY OF A SURFACE FRONT FORMING JUST SOUTH OF THE AREA. HOWEVER THIS IS ONLY THE GFS SOLUTION AND THE ECMWF MAINTAINS HIGH PRESSURE ACROSS THE AREA. FOR WEDNESDAY NIGHT WAS FINE WITH ALLBLEND POPS OF SLIGHT TO LOW END CHANCE. FOR THURSDAY DECREASED POPS TO LOW END CHANCE WITH QUITE A BIT OF ENSEMBLE VARIABILITY ON PATTERN AND GFS/ECMWF SHOWING COMPLETELY DIFFERENT SOLUTIONS /GFS FASTER AND WETTER WITH UPPER PATTERN/. && .AVIATION /DISCUSSION FOR THE 100900Z TAFS/... UPDATED TO TWEAK CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS... WIDESPREAD VFR CEILINGS AROUND 040 EXPECTED TO CONTINUE OVER THE TAF SITES THROUGH FRIDAY MORNING...TRAPPED UNDER A RATHER STOUT INVERSION. MODEL DATA SUGGEST SYSTEM CURRENTLY COMING OUT OF THE SOUTHERN PLAINS WILL BEGIN MOVING INTO THE LOCAL AREA TOWARDS THE MIDDAY HOURS ON FRIDAY. EXPECTING AREAS OF LIGHT PRECIPITATION TO BEGIN AFFECTING THE TAF SITES BY THAT TIME. THICKNESSES SUPPORT SNOW FOR THE MOST PART...ALTHOUGH SURFACE PROGGED WET BULB TEMPERATURES BY MIDDAY FRIDAY SUGGEST SOME RAIN POSSIBLE AT THE ONSET. AT THIS TIME...PRECIPITATION DOESN/T LOOK HEAVY ENOUGH FOR IFR VISIBILITY RESTRICTIONS THROUGH 101800Z...ALTHOUGH IFR CONDITIONS APPEAR LIKELY LATER IN THE DAY. POTENTIAL EXISTS FOR SOME SURFACE WIND GUSTS AROUND 18 KTS FROM 190-220 HEADINGS TOWARDS MIDDAY FRIDAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JH NEAR TERM...JH SHORT TERM...JH LONG TERM....CRP AVIATION...JAS/CRP