FXUS63 KMKX 200926
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
426 AM CDT SAT SEP 20 2008
.SYNOPSIS...
A SFC LOW PRESSURE TROUGH AND ASSOCIATED COLD FRONT 
STRETCHED FROM JUST EAST OF JAMES BAY ACROSS LAKE SUPERIOR AND 
THROUGH CENTRAL MN OVERNIGHT. AN ASSOCIATED SHORT WAVE KICKED UP 
TSRA NEAR THE TWIN CITIES AND ACROSS THE ARROWHEAD REGION OF MN 
YESTERDAY...BUT QUICKLY DISSIPATED AFTER SUNSET. 
WAA AHEAD OF THIS TROUGH BROUGHT HIGHS IN THE UPPER 70S TO AROUND 80 
ACROSS THE CWA YESTERDAY. DEWPOINT TEMPERATURES ACTUALLY CREPT UP TO 
AROUND 60 IN MANY LOCATIONS...SLIGHTLY HIGHER THAN ANTICIPATED. THIS 
MAY HAVE BEEN DUE TO ALL OF THE RAIN THAT HAS FALLEN OVER THE PAST 
WEEK UPSTREAM IN THE CENTRAL U.S.
HIGH CLOUDS PREVAILED OVER SOUTHERN WISCONIN FOR MOST OF THE DAY 
YESTERDAY...WHICH WAS ASSOCIATED WITH A MID LEVEL DISTURBANCE OVER 
SOUTHERN IL. THE CLOUDS CONTINUED TO LINGER OVERNIGHT. MID CLOUDS 
JUST AHEAD OF THE TROUGH IN NORTHERN WI WILL MAKE THEIR WAY 
SOUTHWARD THIS MORNING.
&&
.SHORT TERM...TODAY THROUGH SUNDAY...
AS THE MAIN CENTER OF THE SFC LOW PULLS NE INTO QUEBEC AND HIGH
PRESSURE SINKS SOUTHWARD...THE BEST FORCING ALONG THE TROUGH OVER
MN AND NORTHERN WI WILL ALSO SHIFT NE...AWAY FROM SOUTHERN WI.
MODELS INDICATE VERY LITTLE FRONTOGENESIS OVER SOUTHERN WI THIS
AFTERNOON AND DISSIPATES ANY BY 00Z. THE ANTICIPATED DEWPOINTS IN
THE UPPER 50S OVER THE AREA MAY HELP TO MOISTEN THE LOWER LEVELS
JUST ENOUGH TO TRIGGER ISOLATED TSRA. NAM AND GFS BOTH INDICATE
RATHER STEEP LAPSE RATES LATE IN THE AFTERNOON.
KEPT LOW POPS AND WENT WITH ISOLATED WORDING IN FCST FOR SHOWERS AND 
TSTORMS FOR THIS AFTERNOON. THE BEST CHANCE FOR PCPN WILL BE ACROSS 
THE NORTHERN CWA DURING PEAK HEATING TIME. AFTER SUNSET...KEPT SCHC 
SHOWERS OVER FAR WEST FOR A COUPLE OF HOURS...THEN EXPECT ANY SHOWER 
ACTIVITY TO DISSIPATE COMPLETELY. 
LINGERING MOISTURE ALONG EASTERLY FLOW OFF THE LAKE MAY BE ENOUGH TO 
INDUCE A FEW ISOLATED SHOWERS ON SUNDAY AS HINTED BY THE GFS AND 
ECMWF...BUT KEPT IT OUT OF THE FCST FOR NOW.
STRONG 850MB TEMPERATURE GRADIENT ALONG THE COLD FRONT IS EXPECTED 
TO STAY TO THE NORTH OF OUR CWA TODAY AND THEN SNEAK OFF TO THE EAST 
ON SUNDAY. THEREFORE...SAT NIGHT LOWS SHOULD STILL RANGE FROM 49 TO 
55F ACROSS THE CWA. EAST WINDS OFF THE LAKE ON SUN WILL KEEP THE 
SHORE IN THE UPPER 60S...WHILE TEMPS MAY SEE THE MID 70S FURTHER 
INLAND. 
.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...
WITH HIGH PRESSURE IN PLACE...PLAN ON PLEASANT WEATHER THROUGH THE 
EARLY PART OF THE WEEK. HIGHS WILL BE IN THE UPPER 70S AND SKIES 
WILL BE MOSTLY SUNNY. THE NEXT CHANCE FOR PCPN LOOKS TO BE FOR WED. 
THE GFS HAS PREFERRED A QUICKER PROGRESSION OF THE FRONT THAN THE 
ECMWF AND NAM. THE NATURE OF THIS WEAKLY FORCED SYSTEM FAVORS THE 
SLOWER SOLUTION.
&&
.AVIATION...
SOME EARLY MORNING FOG SHOULD LIFT SOON AFTER SUNRISE 
THIS MORNING. OTHERWISE...VFR THROUGH PERIOD. COLD FRONT TO PUSH 
THROUGH THE AREA THIS AFTERNOON...COULD TRIGGER ISOLATED 
THUNDERSTORMS.  FRONT WILL BE QUICK TO MOVE DOWN LAKE 
MICHIGAN...REACHING KMKE BY AROUND 22Z AND KENW BY 23Z...OR SO. 
DELAYED TO 00Z AT KMSN. 
&&
.MARINE...
QUICK WIND SHIFT TO THE NORTHEAST BEHIND FROPA THIS 
AFTERNOON. THIS SHOULD OCCUR AT SHEBOYGAN BY 20-21Z...REACHING 
KENOSHA/WINTHROP HARBOR BY 23Z.  GOOD MIXING AND GUSTS LIKELY TO 
GENERATE 3 TO 5 FOOT WAVES BY MID EVENING. SMALL CRAFT ADVISORY  
POSTED FROM 02Z TO 14Z SUNDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 9 AM CDT SUNDAY 
     FOR LMZ643>646.
&&
$$
SHORT/LONG TERM...13/MRC
AVIATION/MARINE...05/DAVIS