000 FXUS63 KDVN 050903 AFDDVN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 300 AM CST FRI DEC 5 2008 .SYNOPSIS... COLD CANADIAN HIGH PRESSURE WILL MOVE EAST OF THE AREA TODAY WHILE AN ALBERTA CLIPPER DIVES SOUTHEAST INTO THE PLAINS. THIS CLIPPER WILL MOVE ACROSS THE REGION TONIGHT BRINGING YET ANOTHER ROUND OF SNOW TO THE AREA. ARCTIC HIGH PRESSURE WILL THEN SETTLE ACROSS THE AREA LATER SATURDAY INTO SUNDAY AND KEEP TEMPERATURES WELL BELOW NORMAL. THE COLD AND ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH NEXT WEEK WITH SEVERAL STORM SYSTEMS EXPECTED TO AFFECT THE REGION. && .SHORT TERM...TODAY AND TONIGHT... QUIET WX EXPECTED TODAY AS HIGH PRESSURE MOVES EAST OF THE AREA. COMPARISON OF 06Z OBS WITH 6 HR MODEL FORECASTS INDICATE ALL WERE TOO WEAK WITH PRESSURE FALLS AHEAD OF THE CLIPPER SYSTEM. THUS EXPECT THE CLIPPER TO BE A BIT MORE VIGOROUS THAN WHAT THE MODELS INDICATE. DRY WEATHER SHOULD BE SEEN THROUGH 03Z TONIGHT AS CONDENSATION PRESSURE DEFICITS REMAIN HIGH. FCST SOUNDINGS INDICATE TOP DOWN SATURATION WITH MOST OF THE AREA ACHIEVING SATURATION BETWEEN 03-06Z. SNOW TO REALLY FALL IN ERNEST 06-12Z TIME FRAME AS FORCING IS QUITE IMPRESSIVE. SHOULD SEE ANOTHER 1-2 INCHES WITH PERHAPS LOCALLY HIGHER AMOUNTS. WILL HOLD OFF ON AN ADVISORY FOR NOW BUT THAT MAY BE SOMETHING TO RECONSIDER ESPECIALLY IF WINDS KICK UP LATE TONIGHT. ...08... .LONG TERM...SATURDAY THROUGH THURSDAY... SATURDAY MORNING...THE STRONG CLIPPER LOOKS BE QUICKLY EXITING THE SOUTHEAST AS FAR AS ACCUMULATING SNOW GOES...HOWEVER...THE TRAVEL ISSUES MAY CONTINUE THROUGH THE DAY AS SNOW BLOWS AND DRIFTS...ESPECIALLY ACROSS THE NORTH HALF WHERE COLDER TEMPS AND DEEPER SNOWPACK WILL PROVIDE MORE MOVABLE SNOW. AN EARLY MORNING COLD FROPA WILL ONCE AGAIN PROVIDE THE CWA WITH ANOTHER NON DIURNAL DAY...WHERE THE HIGH TEMPS HAS LITTLE REAL MEANING AS TEMPS FALL SUNRISE THROUGH SUNSET. FOR NOW...WILL KEEP BLOWING SNOW OUT OF THE GRIDS...BUT THIS MAY NEED TO BE ADDED SHOULD OUR SNOW FORECAST VERIFY WITH TEMPERATURES REMAINING WELL BELOW FREEZING THROUGHOUT THE ENTIRE EVENT. SKIES SHOULD CLEAR DURING THE MORNING...THOUGH SOME STRATO CU IS POSSIBLE WITH FLURRIES. THE FALL ON TEMPS WILL INCREASE AGAIN TOWARDS SUNSET...AS CLEAR SKIES AND GRADUALLY DECREASING WINDS PLUMMET TEMPS ONCE AGAIN INTO THE SINGLE DIGITS. ZERO OR SLIGHTLY BELOW ZERO TEMPS ARE VERY POSSIBLE...BUT WITH SOME CIRRUS POSSIBLE AFTER MIDNIGHT WHEN WINDS DROP OFF...WE WILL KEEP ABOVE THESE VALUES FOR NOW. SUNDAY SHOULD SEE SURFACE RIDGING...BUT OVER RUNNING ALOFT. MODELS ARE SHOWING SATURATION FOR LIGHT SNOWS BY AFTERNOON WEST...AND INCREASING LIFT AND SATURATION FOR SNOW SUNDAY NIGHT INTO MONDAY. THIS SHOULD RESULT IN A DRY SNOW INITIALLY...BUT MAY BECOME WETTER IN NATURES TOWARDS MONDAY AS THE THERMAL PROFILE MODERATES UNDER PERSISTENT WAA. MODELS DIVERGE BEYOND MONDAY MORNING...WITH THE GFS SHOWING A PROLONGED LIGHT SNOW EVENT...THOUGH SOMEWHAT MIXED IN THE SOUTH. THE ECMWF 00Z CONTINUES TO REFLECT A MORE PHASED AND FARTHER NORTH STORM SYSTEM...WITH SEASONALLY HEAVY QPF. NO CHANGES MADE BEYOND MONDAY. IN ALL...THE ENTIRE EXTENDED LOOKS VERY ACTIVE...WITH SEVERAL STORM SYSTEM POSSIBLE...AND OTHER THAN PERIODS OF PCPN...IT LOOKS VERY VERY COLD IN ALL AVAILABLE MODEL GUIDANCE. ...ERVIN... && .AVIATION... CURRENT CIGS 0F 3.5-4.5KFT ACROSS IOWA ARE NOT HANDLED BY ANY MODEL. CIGS JUST ARRIVING AT KCID AND SHOULD REACH KDBQ/KMLI/KBRL PRIOR TO SUNRISE. BASED ON TRENDS...CIGS SHOULD REMAIN VFR WITH A FEW FLURRIES POSSIBLE. WILL NOT INCLUDE ANY PRECIP IN 12Z TAFS. VFR WX EXPECTED THROUGH 03Z BEFORE CIGS/VSBYS COLLAPSE WITH THE ARRIVAL OF NEXT CLIPPER SYSTEM. EXPECT VSBYS TO GO BLO 1SM BY OR AFTER 06Z WITH CIGS OF 1KFT OR LESS. CONDITIONS TO IMPROVE AFTER 12Z SATURDAY. ...08... && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ 08/ERVIN