Issued by NWS Milwaukee/Sullivan, WI
000 FXUS63 KMKX 210922 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 322 AM CST SAT NOV 21 2009 FORECAST FOCUS ON DENSE FOG THIS MORNING...QUIET WEATHER INTO MONDAY NIGHT...PRECIPITATION CHANCES TUESDAY THROUGH THANKSGIVING DAY. LATEST WATER VAPOR IMAGERY INDICATED AN UPPER TROUGH SHIFTING INTO THE WESTERN USA...WITH A DOWNSTREAM UPPER RIDGE OVER THE UPPER MIDWEST...AND A SHORTWAVE TROUGH OVER NORTHERN INDIANA. AT THE SURFACE...HIGH PRESSURE WAS CENTERED OVER SOUTHERN OHIO. .TODAY...LIGHT WINDS AND CLEARING SKIES HELPING FOG FORM ACROSS SOUTH CENTRAL AND PORTIONS OF SOUTHEAST WISCONSIN EARLY THIS MORNING. SOME MID LEVEL CLOUDS LINGERING IN THE NORTHEAST COUNTIES MAY LIMIT THE FOG SOMEWHAT EARLY...BUT THESE CLOUDS SHOULD DISSIPATE WITHIN A FEW HOURS. RUC FORECAST SOUNDINGS ACROSS THE AREA THROUGH 15Z THIS MORNING SHOW A DECENT TEMPERATURE INVERSION JUST ABOVE THE SURFACE. HOWEVER...MOISTURE PROFILE IN THE LOW LEVELS NOT SATURATED...SO SOME QUESTION AS TO IF DENSE FOG WILL OCCUR OTHER THAN IN THE WISCONSIN RIVER VALLEY. LOWEST VISIBILITIES NOT EXPECTED UNTIL THE 11Z TO 14Z TIME FRAME...SO WILL GIVE CURRENT DENSE FOG ADVISORY FOR THE FAR WESTERN COUNTIES AND GREEN COUNTY MORE TIME. AFTER FOG DISSIPATES LATER THIS MORNING...EXPECT A PLEASANT DAY UNDER THE INFLUENCE OF THE HIGH TO THE SOUTHEAST. MOSTLY SUNNY SKIES AND MILD TEMPERATURES ARE EXPECTED...WITH HIGHS IN THE LOWER TO MID 50S. .TONIGHT THROUGH MONDAY NIGHT...FOLLOWED THE CONSISTENTLY DRIER NAM/ECMWF MODELS FOR THIS PERIOD. THE HIGH SLOWLY MOVES FURTHER EAST OF THE REGION...WITH A CONFLUENT ZONE SETTING UP FROM NORTHWEST WISCONSIN SOUTHWEST TO IOWA AND NEBRASKA. ANY LIGHT PRECIPITATION FROM THIS AREA WILL STAY WEST OF THE FORECAST AREA...AS DRY AIRMASS IN PLACE HOLDS STEADY. MENTIONED PATCHY FOG TONIGHT AND SUNDAY NIGHT...WITH SOLID LOW LEVEL TEMPERATURE INVERSION OVER THE AREA. MILD TEMPERATURES TO CONTINUE THROUGH THE PERIOD...WITH A GRADUAL INCREASE IN CLOUDS MONDAY AND MONDAY NIGHT AHEAD OF NEXT SYSTEM. .TUESDAY THROUGH FRIDAY...CONTINUED TO FOLLOW THE ECWMF MODEL FOR THIS PERIOD...PREFERRED BY HPC. THIS CONTINUES TO SHOW CYCLOGENESIS OVER SOUTHEAST NEBRASKA MONDAY NIGHT...THEN MOVES THE LOW SLOWLY EAST NORTHEAST TO NORTHERN ILLINOIS BY 12Z WEDNESDAY...THEN TO THE EASTERN UPPER PENINSULA OF MICHIGAN BY 12Z THANKSGIVING DAY. STRONG UPPER LOW ACCOMPANIES THE SURFACE LOW. BEST LOW LEVEL FRONTOGENESIS AND QPF COMES ACROSS THE AREA TUESDAY AND TUESDAY NIGHT...WITH WEAKER UPWARD MOTION AND QPF WEDNESDAY THROUGH THANKSGIVING DAY. ADJUSTED POPS ACCORDINGLY FOR THIS PERIOD. LOOKS WARM ENOUGH FOR ALL RAIN TUESDAY THROUGH WEDNESDAY. 925MB TEMPERATURES GET COLD ENOUGH FOR A MIXTURE OF RAIN AND SNOW WEDNESDAY NIGHT INTO THANKSGIVING DAY...BUT AM NOT EXPECTING MUCH IN THE WAY OF ACCUMULATING SNOW AT THIS TIME. && .AVIATION...A HIGH PRESSURE RIDGE WILL MOVE EWD ACROSS SRN WI TODAY WITH SLY WINDS DEVELOPING TNT AND SUN AS THE HIGH MOVES EAST OF THE REGION. RADIATIONAL FOG WILL PREVAIL THROUGH 15Z THIS AM WITH IFR TO MVFR VSBYS EXPECTED AT THE TAF SITES OVER SOUTH CENTRAL AND SE WI. LGT RADIATIONAL FOG WILL DEVELOP ONCE AGAIN LATE TNT AROUND 09Z SUN BUT MAINLY REMAIN MVFR VSBYS. ISOLD IFR VSBYS MAY OCCUR ESPECIALLY AT KENW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR WIZ056-062- 067-068. LM...NONE. && $$ SHORT/LONG TERM...08/WOOD AVIATION/MARINE...20/GEHRING
