RSS FeedsIssued by NWS Milwaukee/Sullivan, WI
000 FXUS63 KMKX 242038 AFDMKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 238 PM CST TUE NOV 24 2009 HUGE FOECAST CHALLENGE TODAY WITH VERY COMPLICATED STORM SYSTEM EVOLVING OVER THE NEXT 48HOURS. .TONIGHT...IMPRESSIVE CLOSED/STACKED LOW PRESSURE SYSTEM LOCATED ALONG THE CENTRAL IA/MO BORDER AT MID AFTERNOON WILL LIFT INTO SE WISCONSIN BY 12Z TOMORROW/WEDNESDAY. MOISTURE STREAMING NORTH AHEAD OF IT COMBINED WITH A GOOD JET STREAK ROUNDING THE BASE OF THE LOW WILL BRING A SOLID ROUND OF RAIN INTO THE AREA FOR TONIGHT. THE HIGHEST RAINFALL AMOUNTS SHOULD BE ACROSS THE SOUTH CWA...TAPERING OFF TO THE NORTH. TEMPS ARE WARM ENOUGH TO KEEP IT ALL RAIN. .WEDNESDAY/WEDNESDAY NIGHT...THIS IS THE MOST COMPLEX AND FASCINATING PERIOD. THE FIRST LOW WILL BE LIFTING OFF TO THE NORTHEAST IN THE MORNING WHILE A VERY STRONG MID LEVEL SHORTWAVE DIVES IN FROM THE DAKOTAS...INTO THE BACKSIDE OF THE DEPARTING LOW. THIS PHASING IS BEST SEEN AT THE MID LEVELS AS THE SURFACE FEATURES JUST SHOW THE LOW TO OUR EAST DEEPENING AND DEVELOPING A LITTLE TROFINESS TO THE SOUTHWEST. MOISTURE FROM THE FIRST LOW WILL GET TAPPED AND PULLED INTO THIS CLIPPER TYPE FEATURE THAT BECOMES QUICKLY CLOSED OFF WEDNESDAY EVENING...DEVELOPING A CLASSIC COMMA LOOK THAT ROLLS ACROSS NORTHERN ILLINOIS. THE DREADED SOUTHERN EDGE PRECIP IS SQUARLY OVER THE CWA. THE NAM AND THE ECMWF HAVE BEEN VERY STABLE FROM RUN TO RUN IN THEIR SOLUTIONS TO THIS EVOLUTION...WHILE THE GFS HAS BEEN MORE UNSTEADY. THE GFS JUMPED FARTHER SOUTH AND BECAME WARMER WITH THIS MORNINGS RUN. IT APPEARS COLD AIR WILL WRAP IN FROM THE WEST AND UNDERCUT WARMER AIR TO THE NORTH THAT GETS PULLED AROUND THE FIRST LOW AND INTO THIS SECOND LOW. THIS CREATES AN ATYPICAL PRECIP TYPE DISTRIBUTION WITH THE RAIN AND RAIN/SNOW MIX HANGING ON LONGER ACROSS THE NORTHERN CWA...ESPECIALLY OUR NE...COMPARED TO THE SOUTH. THERE ARE A FEW THINGS OF BIG CONCERN. FIRST...THE BOUNDARY LAYER TEMPS ARE QUESTIONABLE...CAN WE GET COLD ENOUGH FOR SNOW ACCUMULATION. THE NAM/ECMWF/CANADIAN SAY YES. THE GFS/CRAS...ESPECIALLY CRAS...WOULD SAY NO. BUT TEMPS ALOFT ARE QUITE COLD WITH 500MB AROUND -28 AND 700MB AT -10. SOME OF THE STRONGEST UVV/OMEGA ROLLS RIGHT ACROSS THE CWA AND THERE IS POTENTIAL FOR CONVECTION WITH ELEVATED INSTABILITY ABOVE 650MB. THATS A BIT HIGH BUT STILL AVAILABLE. GIVEN THE STRONG DYNAMICS AND POSSIBLE CONVECTION...WE WOULD EASILY TAP THAT COLDER AIR ALOFT AND COOL THE BNDRY LAYER DOWN VERY RAPIDLY. THE SOUTHERN CWA COULD SEE SOME MODERATE SNOW FOR A TIME AS THESE STRONG DYNAMICS PASS THROUGH. THE GROUND IS WARM AND WILL MELT SNOW...BUT IT COULD ACCUMULATE TO 3 INCHES IN A VERY NARROW AREA...THEN MELT QUICKLY. JUST WHERE THAT HAPPENS AS THIS THING EVOLVES IS TOUGH TO PIN DOWN RIGHT NOW. BUT BEST CHANCE LOOKS TO BE FROM MADISON SOUTH AND MAINLY WEST OF LAKE GENEVA. .THURSDAY...THIS LOW PULLS OUT QUICKLY ON THURSDAY WITH COLD AIR SPILLING IN. ANY MIX LEFT IN THE EAST DURING THE MORNING WILL TRANSITION OVER TO LIGHT SNOW. ANY ADDITIONAL ACCUMS WILL BE LIGHT AND MAILY LIMITED TO THE EAST. .THURSDAY NIGHT AND BEYOND...DRY BY THURSDAY NIGHT WITH GOOD COLD AIR ADVECTION...A CHILLY NIGHT. WARM ADVECTION KICKS BACK IN FOR FRIDAY THROUGH SATURDAY AS THE UPPER LEVEL FLOW PATTERN SHIFTS QUICKLY FROM NORTHWEST TO SOUTHWEST. NEXT WEATHER MAKER SHOULD ARRIVE SUNDAY NIGHT AND MONDAY AND PRECIP TYPE IS QUESTIONABLE. && .AVIATION...IFR VISIBILITIES AND LIFR CEILINGS EXPECTED UNTIL MAIN AREA OF RAIN MOVES INTO KMSN AND KENW BY 00Z WEDNESDAY...AND KUES AND KMKE BY 01Z WEDNESDAY. SURFACE AND UPPER LOW MOVING THROUGH THE AREA OVERNIGHT AND INTO WEDNESDAY MORNING WILL BRING PREVAILING RAIN...WITH IFR VISIBILITIES AND IFR/LIFR CEILINGS CONTINUING. MAY BE A LULL IN THE RAIN LATE MORNING TO EARLY AFTERNOON...UNTIL NEXT UPPER LOW SWINGS INTO THE REGION WITH MORE RAIN BY LATE AFTERNOON. IFR/LIFR CEILINGS AND MVFR/IFR VISIBILITIES WILL PREVAIL THROUGH THE DAY. && .MARINE...WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA WITH THE PASSING LOW PRESSURE SYSTEM TONIGHT INTO EARLY WEDNESDAY. BRISK NORTHWEST WINDS AND HIGHER WAVES ARE POSSIBLE THURSDAY AND THURSDAY NIGHT...AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND GOOD MIXING ENSUES. THE HIGH WAVES MAY LINGER INTO FRIDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ SHORT/LONG TERM...DAVIS AVIATION/MARINE...WOOD
