FXUS63 KDLH 121800 AAB AFDDLH AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 1200 PM CST FRI MAR 12 2010 .AVIATION...VERY LARGE CIRCULATION... ASSOCIATED WITH INTENSE MID LVL LOW OVER CTRL PLAINS...WILL KEEP A LAYER OF DEEP MOISTURE OVER TAF SITES. PERIODS OF PRECIP WILL AFFECT CWA AS INDIVIDUAL DISTURBANCES MOVE AROUND MAIN SYSTEM. IFR ACROSS SRN SITES TODAY AND THEN LOWERING TO LIFR/VLIFR OVERNIGHT. KINL/KHIB WILL HAVE BEST CHANCE OF DECENT CONDITIONS WITH MVFR/VFR BASES TODAY...THEN LOWERING TO IFR OVERNIGHT. && .PREV DISCUSSION... /ISSUED 1103 AM CST FRI MAR 12 2010/ UPDATE... INCREASED WINDS ALONG THE SHORE...ESPECIALLY THE NORTH SHORE TODAY. MADE MINOR CHANGES...INCLUDING CHILLING THE SHORE DURING THE DAYTIME. DISCUSSION... HIGH DEW POINTS ARE BEING ADVECTED BACK AHEAD OF A TROUGH FROM OVER PINE COUNTY THROUGH MKE TO SDF. WET DEW POINTS HAVE ADVECTED NORTHWARD AND NORTHWESTWARD AHEAD OF THE TROUGH. A MESO- LOW HAS FORMED AT THE NORTHWEST TIP AND RAPIDLY DEEPENED...THE VERY SHORT- TERM RUC IS THE ONLY MODEL TO PICK THIS UP. ANY THUNDER THAT WOULD DEVELOP ALONG THE TROUGH WOULD REMAIN SOUTHEAST OF OUR AREA. HOWEVER...THE MESO-LOW HAS FORMED A TIGHT GRADIENT OVER THE TWIN PORTS AREA AND THE GRADIENT IS WORKING ITS WAY UP THE NORTH SHORE. SO...WE INCREASED WINDS...ESPECIALLY WHERE TOPOGRAPHIC FUNNELING TAKES PLACE...THROUGH THIS AFTERNOON...THE LOW IS EXPECTED TO MOVE SOUTHWEST AND WEAKEN LATER THIS AFTERNOON. WITH AN ONSHORE FLOW THROUGH THE WEEKEND...WE LOWERED AFTERNOON TEMPERATURES ALONG THE COAST A LITTLE. THE WIND IS MITIGATING FOG RESULTING FROM SNOW MELT...AND RATHER MAINTAINING A LOW CEILING. FEW IF ANY OTHER CHANGES WERE NEEDED. PREV DISCUSSION... /ISSUED 557 AM CST FRI MAR 12 2010/ UPDATE...12Z TAF DISCUSSION... AVIATION...EXPECT IFR/LIFR CONDITIONS TO PERSIST THROUGH MOST OF THE TAF PERIOD. THERE MAY ALSO BE MVFR AT TIMES IN PRECIP...WITH EVEN VFR ALONG THE NORTHERN AND EASTERN NORTH SHORE FROM BFW TO GNA. THE MAIN FORCING WITH THE NEXT WAVE OF PRECIPITATION IS EXPECTED TO CONTINUE DURING THE 12Z-18Z TIME (6AM - NOON)...AND GENERALLY FOCUSED ALONG A LINE FROM KBRD...TO KDLH...TO KHYR. THIS AREA IS WHERE A DECENT BAND OF 925-700 FRONTOGENESIS IS ROTATING WESTWARD ACCOMPANIED BY AN UPPER LEVEL DISTURBANCE SWINGING WESTWARD AROUND THE PARENT UPPER LEVEL LOW. THIS UPPER LOW WILL SINK SOUTHWARD DURING THE DAY...AND WILL THUS KEEP THE HEAVIER PRECIPITATION AWAY FROM KINL...WITH KHIB ON THE NORTHERN FRINGE...AND FRONTOGENESIS WILL WEAKEN WITH THIS NEXT BATCH OF RAIN. NO LIGHTNING HAS BEEN DETECTED IN ANY OF THE SHOWER ACTIVITY IN THE LAST FEW HOURS EXCEPT IN CENTRAL WISCONSIN...ASSOCIATED WITH ANOTHER BAND OF SHOWERS/THUNDERSTORMS AND YET ANOTHER DISTURBANCE MOVING NORTHWARD. LITTLE TO NONE IS EXPECTED ATTM ACROSS THE NORTHLAND...WITH LIMITED INSTABILITY SUGGESTED BY THE NAM/RUC...THOUGH IT IS CERTAINLY PLAUSIBLE THAT A CLAP OF THUNDER MAY APPROACH NORTHWESTERN WISCONSIN. PRECIPITATION SHOULD DECREASE IN COVERAGE THIS AFTERNOON AND MORE SO THIS EVENING. FOG WILL BE COMMON TONIGHT INTO EARLY SATURDAY MORNING AS PRECIPITATION DIMINISHES SIGNIFICANTLY...AND WINDS SLACKEN A TOUCH. DONOFRIO PREV DISCUSSION... /ISSUED 309 AM CST FRI MAR 12 2010/ DISCUSSION...SHORT TERM REMAINS ON PCPN AND FOG. MAIN SFC LOW CENTER CONTINUES TO FLOAT AROUND WEST CENTRAL IA WHILE ANOTHER WEAK SFC REFLECTION IS ORGANIZING IN SOUTHERN WI. THE WI LOW IS IN RESPONSE TO UPPER LEVEL ENERGY ROTATING WESTWARD FROM NE WI. THIS SFC LOW WILL DRIFT INTO NW WI WHILE THE UPPER LEVEL ENERGY EVOLVES INTO A CLOSED LOW IN THE SAME VICINITY. MORE RAIN WILL ACCOMPANY THESE FEATURES TODAY AND HAVE ALIGNED POPS ACCORDINGLY. THE RAIN WILL FURTHER THE SNOW MELT AND COMBINE WITH GENERALLY LIGHT WINDS TO ALLOW THE FOG TO PERSIST. SOME AREA RIVERS ARE BEGINNING TO OPEN UP AS A RESULT. SOME ICE JAMS MAY OCCUR ON RIVERS PRONE TO ICE JAMS. RAINFALL AMOUNTS WILL BE LIGHT SO NO FLOODING ISSUES EXPECTED ATTM. CANCELLED THE DENSE FOG ADVISORY AS CRITERIA IS NO LONGER BEING MET AND WITH ANTICIPATED RAIN...VSBYS SHOULD REMAIN GREATER THAN 1/4 MILE. AS THE UPPER LOW SLOWLY MOVES TO THE WEST...WILL SEE A BREAK IN THE ACCUMULATING RAIN TONIGHT. THE BULK OF THE LIFT WILL ACCOMPANY THE UPPER LOW..BUT ENOUGH WILL LINGER TO SQUEEZE OUT SOME ISOLD SHOWERS/DRIZZLE. MORE FOG EXPECTED AS SFC WIND WILL BE RELATIVELY LIGHT. THE CUT OFF LOW WILL MEANDER FURTHER WESTWARD INTO EASTERN ND ON SATURDAY. MEANWHILE...ONE MORE SPOKE OF SHORT WAVE ENERGY WILL CLIP THE EASTERN TIER OF THE FA IN THE MORNING. HAVE POPS IN PLACE TO ACCOUNT FOR THIS WAVE. BY SATURDAY AFTERNOON...THE FA IS UNDER THE INFLUENCE OF A COL AND EXPECT ACCUMULATING RAIN TO END. HAVE A MENTION OF DRIZZLE AND MORE FOG AS UPPER LEVEL DIVERGENCE REMAINS IN THE NEIGHBORHOOD FROM THE UPPER LOW. /GSF EXTENDED...SATURDAY NIGHT THROUGH WEDNESDAY... THE MAIN FORCING ASSOCIATED WITH THE DEPARTING UPPER LEVEL LOW WILL BE WELL SOUTH OF OUR AREA AND EAST OF OUR AREA. FOG WILL STILL BE AROUND ON SATURDAY NIGHT AND HAVE ADDED THIS TO THE FORECAST FOR THIS PERIOD. A PIECE OF ENERGY FROM THIS UPPER LOW WILL BREAK OFF FROM ITS PARENT SYSTEM...AND THIS WILL KEEP A SMALL CHANCE FOR A RAIN SHOWER AROUND ON SUNDAY INTO MONDAY...WITH THE BEST CHANCES FOCUSED IN OUR WESTERN AREAS. ANOTHER DISTURBANCE WILL THEN SWING THROUGH THE AREA MONDAY INTO TUESDAY...BUT THE CONSISTENT ECMWF HAS BEEN SLOWER THAN THE GFS WITH THIS NEXT WAVE...AND HAS ALSO BEEN DRY FOR THE MOST PART...WHILE WEAKENING THE UPPER DISTURBANCE WITH HIGH PRESSURE BUILDING IN. WITH VERY WEAK LIFT EXPECTED AND NO TRUE SURFACE REFLECTION...SIGNIFICANT MODEL DIFFERENCES IN TIMING... AND NOT WANTING TO DO ANY FLIP-FLOPPING WITH POPS...WE WILL LEAVE THE FORECAST DRY FOR MONDAY NIGHT INTO TUESDAY. BY MIDWEEK...CONDITIONS SHOULD BE MAINLY DRY AND MILD AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE WEEKEND...WITH THE WARMEST TEMPS MOST LIKELY ON SUNDAY. A BRIEF COOL DOWN IS EXPECTED TUESDAY...BUT WAA REALLY PICKS BACK UP ON WEDNESDAY. /DONOFRIO && .POINT TEMPS/POPS... DLH 39 35 39 34 / 70 30 20 20 INL 44 35 47 34 / 40 30 20 20 BRD 45 35 46 37 / 70 40 20 20 HYR 49 39 50 37 / 60 30 20 20 ASX 44 38 44 37 / 70 30 20 20 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ EOM/CANNON/CANNON