Issued by NWS Huntsville, AL
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000 FXUS64 KHUN 211147 AAA AFDHUN AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HUNTSVILLE AL 547 AM CST SAT NOV 21 2009 .UPDATE... FOR 12Z AVIATION. && .AVIATION... CIRRUS CANOPY WILL GRADUALLY LOWER/THICKEN AS A LOW PRESSURE SYSTEM APPROACHES FROM THE SW. VERY DRY AIR IN THE LOW-LVLS WILL LIKELY PREVENT PCPN AT TERMINALS UNTIL AFTER 22/00Z. PRIMARILY LGT RAIN WITH VFR CONDITIONS ARE ANTICIPATED BTWN 06Z AND 12Z. HOWEVER...MVFR VIS MAY OCCUR TOWARD THE END OF THE TAF PERIOD IF MDT RAIN DEVELOPS EARLIER THAN EXPECTED. && .DISCUSSION... /ISSUED 215 AM CST SAT NOV 21 2009/ SHORT TERM (TODAY THROUGH MONDAY)... AS EXPECTED...HIGH CLOUDS HAVE SPREAD ACROSS THE AREA...AND THIS SETS THE STAGE FOR NOT THE NICEST OF WEEKENDS. HOWEVER...IT LOOKS INCREASINGLY LIKELY THAT TODAY WILL NOT BE BAD...JUST WITH NOT A LOT OF SUNSHINE. TEMPS TODAY WILL IN FACT BE RATHER MILD...REACHING THE LOWER AND PERHAPS MID 60S. RAIN IS LOOKING LESS AND LESS LIKELY TODAY WITH SOUNDINGS SHOWING ALMOST ALL THE MOISTURE ABOVE 10 KFT... EXCEPT SOUTH AND WEST LATE THIS AFTERNOON. WILL REMOVE THE SLIGHT CHANCE OF SHOWERS. HOWEVER...SOME PCPN OFF TO THE WEST IN ARKANSAS IS REACHING THE GROUND IN TRACE AMOUNTS...EVEN OUT OF THE 10 KFT CEILINGS. SO WILL CARRY A SLIGHT CHANCE OF A SPRINKLE THIS AFTERNOON. MODELS HAVE LOST THEIR WAY REGARDING THE APPROACHING GULF COASTAL SYSTEM...WITH PLENTY OF MODEL DISAGREEMENT. THE GFS AND ITS ENSEMBLES ARE FAVORING AN EVEN MORE SOUTHERLY/EASTERLY MOVEMENT THAN BEFORE...LEAVING PARTS OF THE AREA ALMOST COMPLETELY DRY. THIS IS A TOTAL FLIP FROM PRIOR RUNS. THE NAM IS MORE CONSISTENT BUT ALSO MUCH SLOWER TO BRING IN PRECIP...NOT UNTIL LATE TONIGHT OR EVEN SUNDAY. WILL BE CUTTING BACK POPS EXCEPT IN THE SOUTHERN COUNTIES...AND FOCUSING ON THE AFTER MIDNIGHT PERIOD. DESPITE CUTTING POPS...I REMAIN ABOVE ALL THE MODEL GUIDANCE POPS. WITH CLOUDS AND MOISTURE IN PLACE...LOWS SHOULD REMAIN AROUND 50. UPPER LOW COMES ACROSS...IN SOME FORM...ON SUNDAY. GFS IS TOO FAST WITH THAT MOVEMENT AND WILL NOT BE FOLLOWED. IN GENERAL...SUNDAY LOOKS CLOUDY...RAW...BREEZY...AND WITH A GOOD CHANCE OF RAIN. GIVEN THAT THE SYSTEM WILL BE WEAKENING...UNCERTAINTY ABOUNDS. WILL AGAIN HOLD POPS STEADY IN THE EAST AND TAPER THEM LOWER TO THE NORTHWEST. TEMPS WILL HARDLY MOVE...STAYING AT BEST IN THE MID 50S. ALTHOUGH THE SYSTEM DISSIPATES SUNDAY NIGHT...THERE IS NO FROPA...AND THUS NO AIRMASS CHANGE. MEANWHILE...MODELS SHOW A NRN STREAM UPPER WAVE COMING ACROSS. SOUNDINGS LOOK QUITE FAVORABLE FOR LOW CLOUDS AND DRIZZLE...PERHAPS EVEN A LIGHT SHOWER. WILL KEEP THE MENTION OF SLIGHT CHANCE RAIN OR DRIZZLE SUNDAY NIGHT...AND EXPAND IT THROUGH MONDAY MORNING IN THE EASTERN COUNTIES. SOME BREAKS IN THE CLOUDS ARE POSSIBLE MONDAY AFTERNOON...SO HIGHS MAY APPROACH 60. EXTENDED (MONDAY NIGHT THROUGH NEXT SATURDAY)... THE REST OF THE FORECAST IS QUIET...DESPITE THE PATTERN BEING ACTIVE. AN APPROACHING NRN STREAM COLD FRONT IS FORECAST TO MOVE THROUGH SOMETIME TUESDAY /OR MAYBE TUESDAY NIGHT/. NOT A LOT OF FORCING...BUT FRONTAL FORCING MAY SPARK A SHOWER OR TWO IN THE VICINITY OF THE FRONT. WILL KEEP A SLIGHT CHANCE MENTION ON TUESDAY AFTERNOON EVERYWHERE...AND IN THE EAST ONLY TUESDAY EVENING. THIS USHERS IN COOLER TEMPERATURES FOR WEDNESDAY...WHICH ARE REINFORCED BY A STRONGER DRY COLD FRONT WEDNESDAY NIGHT. BY THE WAY...THE ECMWF REMAINS ABOUT A DAY SLOWER WITH BOTH OF THESE FRONTS AND FOR NOW...IT IS NOT BEING FOLLOWED. THANKSGIVING AND THE DAY AFTER LOOK DRY BUT RATHER CHILLY...WITH HIGHS 50 TO 55 AND LOWS 30 TO 35. A BIT OF A WARMUP LOOKS POSSIBLE TO START NEXT WEEKEND...BUT IT MAY NOT LAST LONG WITH ANOTHER FRONT CURRENTLY SHOWN LATE NEXT WEEKEND. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ AVIATION...KDW DISCUSSION...JE/23
