478 FXUS63 KIND 051442 AFDIND AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 1042 AM EDT THU APR 5 2012 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... A FRONT STALLED SOUTH OF THE AREA WILL KEEP CHANCES FOR RAIN AND ISOLATED THUNDER ACROSS THE SOUTH EARLY TODAY...THEN AS THIS FRONT DROPS FARTHER SOUTH CONDITIONS WILL DRY OUT ACROSS CENTRAL INDIANA BY THIS AFTERNOON. AN UPPER LOW PRESSURE SYSTEM SLIDING EAST ACROSS THE PLAINS DIVES THROUGH THE SOUTHEASTERN US AND WILL CAUSE TEMPERATURES TO FALL ACROSS THE AREA TO MORE SEASONAL LEVELS AND BRING THE POTENTIAL FOR LOW TEMPERATURES NEAR OR BELOW FREEZING IN THE SHORT TERM. A COUPLE OF WEAK SYSTEMS MOVING THROUGH WILL BRING LOW CHANCES FOR PRECIPITATION SATURDAY NIGHT AND AGAIN ON MONDAY. && .NEAR TERM /REST OF THE DAY/... RAW E/NE FLOW MAKING FOR A COOL MORNING OVER CENTRAL INDIANA UNDER MOSTLY CLOUDY SKIES. TEMPS AS OF 14Z WERE MAINLY HOLDING IN THE MID AND UPPER 40S DUE TO THE CLOUD COVER. AREA OF PRECIP THAT WAS PRESENT OVER SOUTHERN COUNTIES EARLIER THIS MORNING HAS REALLY DROPPED OFF IN COVERAGE OVER THE LAST THREE HOURS AS LOW LEVEL DRY AIR IS INFILTRATING FROM THE NORTHEAST AND BETTER FORCING ALOFT IS SHIFTING SOUTHWEST OF THE AREA IN CLOSER PROXIMITY TO THE LOCATION OF THE UPPER LOW. WITH AN AREA OF PRECIP JUST SOUTH OF DAVIESS/MARTIN COS...WILL MAINTAIN LOW CHANCE POPS INTO THE MID AFTERNOON OVER SOUTHERN COUNTIES. WITH VERY WEAK ELEVATED INSTABILITY STILL PRESENT OVER SOUTHERN INDIANA...WILL MAINTAIN AN ISOLATED THUNDER MENTION THROUGH NOON. ELSEWHERE...APPEARS TOO MUCH DRY AIR IS PRESENT IN THE LOW LEVELS FOR ANY ADDITIONAL PRECIP TO FALL. OTHER CHANGES TO THE FORECAST FOCUSED ON WINDS...TEMPS AND THE CLOUD COVER FOR THE REMAINDER OF THE DAY. CURRENT VIS SATELLITE IMAGERY SHOWING PLENTY OF MID AND HIGH LEVEL CLOUDS EXTENDING ALL THE WAY INTO FAR NORTHERN INDIANA. CURRENT SHORT RANGE MODEL GUIDANCE INDICATING THESE CLOUDS MAY END UP TAKING MUCH OF THE AFTERNOON TO COMPLETELY SCATTER OUT OF THE FORECAST AREA. THIS WILL HAVE AN IMPACT ON TEMPS AND HAVE BUMPED HIGHS DOWN A COUPLE DEGREES AS A RESULT. ALSO BUMPED UP WIND GUSTS FOR THE REST OF THE DAY BASED ON CURRENT OBS WITH SUSTAINED AT 15-20MPH AND GUSTS CLOSER TO 25 TO 30MPH. ZONE AND GRID UPDATES OUT. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... SINCE MODELS DEPICT A LARGE RIDGE BUILDING OVER THE REGION THIS ENTIRE PERIOD THE WEATHER WILL REMAIN DRY (AND CLEAR TO MOSTLY CLEAR!)...HOWEVER CONCERN THEN TURNS TO FROST BOTH FRI AND SAT MORNINGS AS TEMPERATURE DIP NEAR OR BELOW THE FREEZING MARK. TONIGHT LOOKS TO BE THE COLDEST NIGHT OF THE PERIOD. BASED ON THICKNESSES CURRENT FORECAST LOWS FOR FRIDAY MORNING LOOK VERY REASONABLE...HOWEVER AM VERY CONCERNED FOR THE SLIGHTLY STRONG LLVL WINDS THAT DEVELOP LATE TONIGHT WHICH COULD PUT A HAMPER ON FROST FORMATION...EVEN IN COUNTIES TO THE NORTH WHERE SUB-FREEZING TEMPERATURES ARE IN THE FORECAST. SURFACE WINDS OF 10KT OR GREATER LOOK LIKELY AS THE GRADIENT LOOK STRONG ENOUGH WHILE THE AFOREMENTIONED LOW PRESSURE SYSTEM IN THE SYNOPSIS PULLS FARTHER AWAY TOWARD THE MID ATLC REGION. OPTED TO DROP THE FREEZE WATCH AND REPLACE THIS SAME AREA UNDER A FROST ADVISORY FOR AREAS TO WIDESPREAD FROST DEVELOPMENT AND PUT PATCHY FROST ELSEWHERE IN THE GRIDS...HOWEVER WITHOUT A HEADLINE. (WILL MENTION IT IN THE HWO HOWEVER.) DURING THE DAY FRIDAY SHOULD SEE AMPLE SUNSHINE WITH HIGH PRESSURE ALMOST DIRECTLY OVERHEAD. FRIDAY NIGHT WITH HIGH PRESSURE CENTER VERY CLOSE EXPECT WINDS TO DROP OFF TO LESS THAN 5 KTS. IDEAL RADIATIONAL COOLING CONDITIONS COULD BE IN PLACE WITH THE LACK OF WINDS AND CLEAR SKIES AND THUS WENT COOLER THAN PREVIOUS FORECAST. WITH TEMPERATURES AT OR ABOVE FREEZING BUT ONLY UP TO THE MID 30S AND LIGHT WINDS INCLUDED PATCHY FROST ACROSS THE ENTIRE AREA FOR LATE FRIDAY NIGHT/EARLY SATURDAY MORNING. WILL ALSO NEED TO MONITOR THIS PERIOD FOR ADDITIONAL FROST/FREEZE HEADLINE WHICH MAY BE NEEDED. TEMPERATURES BEGIN TO REBOUND TO ABOVE NORMAL BY SATURDAY...WHICH LOOKS LIKE A PLEASANT SPRING DAY WITH MOSTLY CLEAR SKIES AND HIGHS IN THE MID TO UPPER 60S. NEXT APPROACHES THE REGION LATE SAT AND CROSS THE AREA SATURDAY NIGHT. THIS FRONT IS LOOKING WEAKER AND DRY AS OF LATE SO BACKED OFF ON POPS UNTIL AFTER 06Z SUNDAY AND KEPT ONLY 20-30% OVER THE AREA ATTM. CENTRAL INDIANA SHOULD BE DRY BY LATE SUNDAY AFTERNOON. && .LONG TERM /SUNDAY THROUGH THURSDAY/... GUIDANCE CONTINUES TO ADVERTISE A FRONTAL PASSAGE EARLY ON SUNDAY...AND THE CONSOLIDATION OF ONE OR MORE UPPER LEVEL WAVES INTO A COLD VORTEX OVER THE NORTHEASTERN PORTION OF THE COUNTRY EARLY NEXT WEEK. ONE OF THESE LOWS WILL BRING THE POSSIBILITY OF SHOWERS TO THE FORECAST AREA MONDAY AND MONDAY NIGHT...BUT ASIDE FROM THIS...AND A LINGERING SLIGHT CHANCE OF SHOWERS EARLY SUNDAY MORNING...A DRY FORECAST DOMINATES THE EXTENDED. TEMPS WILL LIKELY BE COOLER THAN RECENT DAYS...AND PERHAPS EVEN BELOW CLIMO ON A FEW DAYS...BUT NOT SIGNIFICANTLY SO. && .AVIATION /DISCUSSION FOR THE 05/12Z TAFS/... VFR THROUGH THE PERIOD...WITH THE EXCEPTION OF POSSIBLE BRIEF MVFR RESTRICTIONS IN DISSIPATING BAND OF SHOWERS OVER HUF/BMG. UPPER LOW WILL PULL AWAY TO THE SOUTH TODAY AND TONIGHT. SHOWERS WILL END AT HUF/BMG WITHIN THE FIRST FEW HOURS OF THE PERIOD...WITH MIDLEVEL CLOUD REMAINING THROUGH MUCH OF THE DAY. SKIES WILL CLEAR TONIGHT AS HIGH PRESSURE ADVANCES INTO THE AREA. WINDS WILL GENERALLY BE NORTHEASTERLY THROUGH THE PERIOD. GUSTS TO AROUND 20KT ARE EXPECTED AT TIMES DURING THE DAY...SUBSIDING IN TYPICAL DIURNAL FASHION THIS EVENING. && .IND WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 4 AM TO 9 AM EDT FRIDAY FOR INZ021-028>031- 035>046-048-049-057. && $$ SYNOPSIS...SMF NEAR TERM...RYAN SHORT TERM...SMF LONG TERM....NIELD AVIATION...NIELD