FXUS63 KMKX 070940 AAA
AFDMKX
AREA FORECAST DISCUSSION...UPDATED MARINE
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
340 AM CST MON DEC 7 2009
.DISCUSSION...FORECAST FOCUS SQUARELY ON THE MAJOR WINTER STORM FOR
TUESDAY NIGHT INTO WEDNESDAY. WE ALSO HAVE ISSUES WITH THE SNOW THIS
MORNING. LASTLY THE COLD BLAST IN THE WAKE OF THE BIG STORM.
TODAY- CONFIDENCE...MEDIUM
WATER VAPOR/RUC COMBO SHOWS MAIN 22 UNIT VORT CENTER SHIFTING
NORTHEAST FROM EASTERN IOWA. SURFACE LOW CENTER NE MO WITH INVERTED
TROUGH AXIS INTO SE WI. MODEL QPF AXIS ACROSS CENTRAL/NORTHERN CWA
ALIGNS WITH WHERE DEFORMATION ZONE PRECIP SHIELD IS LAYING OUT PER
88-D MOSAIC. VERTICAL MOTION ASSOICATED WITH UPPER WAVE CLEARS THE
CWA BY 18Z. LAKE ENHANCEMENT VICINITY SOUTHERN SHEBOYGAN/NORTHERN
OZAUKEE AND NORTHEAST WASHINGTON COUNTIES IN FAVORED 1000-850
CONVERGENCE ZONE. DELTA T VALUES FROM THE NAM ARE 15C. WILL HOIST AN
EARLY ADVISORY FOR THOSE 3 COUNTIES WITH AMOUNTS LOCALLY GETTING UP
TO 5 INCHES. WILL THEN LEAN MORE TOWARDS HPC WITH NO MEASURABLE
AFTER 18Z. SOUNDINGS SHOW MUCH OF THE COLUMN DRYING...THOUGH LOW
LEVEL MOISTURE AND WEAK SURFACE TROUGHINESS SUGGEST SOME FLURRIES
WILL LINGER.
TONIGHT- CONFIDENCE...LOW TO MEDIUM
UPPER LEVELS SUGGEST WEAK RIDGING HOWEVER THE GFS IS RATHER
AGGRESSIVE WITH WARM AIR ADVECTION LIGHT SNOW DEVELOPING. IN FACT
THERE IS A FAVORABLE DELTA T OF AROUND 15C WITH ONSHORE COMPONENT.
GFS HAS 0.01 COVERING THE WHOLE CWA WHILE THE NAM HOLDS THINGS OFF.
WILL GO DRY FOR NOW.
TUESDAY- CONFIDENCE...LOW TO MEDIUM
UPPER SYSTEM MOVES OUT INTO THE PLAINS AND THE ISENTROPIC COMPONENT
OF THIS STORM KICKS IN WITH EARNEST. IMPRESSIVE ADIABATIC OMEGA WITH
WIDESPREAD QPF DEVELOPING ACROSS ALL OF THE CWA.
TUESDAY NIGHT INTO WEDNESDAY- CONFIDENCE...MEDIUM
MAJOR WINTER STORM WILL HAVE A TREMENDOUS IMPACT ON SOUTHERN
WISCONSIN. CONFIDENCE INTO THE HIGH CATEGORY THAT MUCH OF THE CWA
WILL SEE CLOSE TO A FOOT OF SNOW. WHERE THE CONFIDENCE IS STILL A
SMIDGE LOWER IS IN THE SOUTHEAST CORNER NEAR THE LAKE WHERE
QUESTIONABLE THERMAL PROFILE COMES INTO PLAY. THE NAM IS THE WARMEST
SOLUTION AT THE MOMENT WITH THE 850 LOW TRACKING OVER MILWAUKEE. AM
DISCOUNTING THIS THOUGH AND LEANING TOWARDS THE GFS/ECMWF WHICH HAS
THE 850 LOW TRACKING THROUGH NORTHERN CHICAGO SUBURBS AND OFF TO THE
NORTHEAST WITH THE ECWMF SOUNDING IN THE FAR SE CORNER STILL
SHOWING ALL SNOW FOR THE EVENT. 700 LOW TRACK FROM THE ECMWF AND
GFS PUTS MUCH OF THE CWA IN THE FAVORED NORTHERN HALF OF THE 700
CLOSED CONTOUR. INGREDIENTS CHARTS ARE SHOWING SOME WEAK
CONVECTIVE POTENTIAL. INSTABILITY LOOKS LIMITED BUT IMPRESSIVE 30
TO 50 UNITS OF Q VECTOR CONVERGENCE IN THE 700-500 MILLIBAR LAYER.
GETTING ANYWHERE FROM 0.90 TO 1.10 INCHES OP LIQUID AND USING A
COMBINATION OF THICKNESS TECHNIQUE AND ROEBBER TECHNIQUE WILL LEAN
TOWARDS LOWER RATIOS CLOSER TO 10:1 ...ESPECIALLY IN THE
SOUTHEAST. CAN SEE WHERE THE WESTERN AND NORTHERN CWA MAY SEE
HIGHER RATIOS. THE COBB RATIOS LOOK A BIT ON THE HIGH SIDE. FOR
NOW...THINK WE ARE LOOKING AT A GOOD 8-12 INCHES CWA WIDE. THE 925
WINDS REALLY RAMP UP AHEAD OF THE LOW TUESDAY EVENING WITH SOME
SUGGESTION THAT BLIZZARD CRITERIA COULD BE MET OR CLOSE TO BEING
MET FOR A TIME. THEN WINDS EASE A BIT AS LOW GETS CLOSER. THE
STRONGEST WINDS ARRIVE ON WEDNESDAY WHEN LOW PULLS OFF TO THE EAST
A BIT BUT THEN HEAVIEST PRECIPITATION RATE NOT COINCIDENT WITH
THESE WINDS. SO OVERALL CONFIDENCE IN COVERAGE AND DURATION OF
TRUE BLIZZARD TYPE CONDITIONS LOW AT THIS POINT...BUT SOMETHING TO
MONITOR.
THURSDAY- CONFIDENCE...MEDIUM
STRONG LOW LIFTS NORTHEAST AWAY FROM THE AREA BUT GRADIENT STILL
FAIRLY TIGHT. BROAD CYCLONIC FLOW WITH COLD TEMPERATURES...1000-500
MILLIBAR THICKNESSES AROUND 500DM AND 925 TEMPS OF -13 TO -16C. A
REAL TASTE OF WINTERLIKE COLD SETTING UP HERE.
FRIDAY- CONFIDENCE...LOW TO MEDIUM
START TO SEE SOME WARM AIR ADVECTION AS RIDGE AXIS SHIFTS OFF TO THE
EAST. 925 TEMPS AND THICKNESSES MODIFY
&&
.AVIATION...MVFR/IFR CIGS/VSBYS ASSOCD WITH AREAS OF SNOW TO EASE TO
MAINLY MVFR CIGS LATER THIS MRNG AS SNOW ENDS. CIGS MAY BRIEFLY
RETURN TO VFR LATE TODAY OR TNGT BEFORE -SN RETURNS TUE MRNG.
&&
.MARINE...SMALL AREA OF 1830Z MODIS SEA SURFACE TEMP SHOWS NEARSHORE
TEMPS AROUND 5C. WL WATCH CLOSELY FOR POSSIBLE SMALL CRAFT ADVY NRN
ZONES FOR EARLY THIS MORNING DUE TO STRONG LOW LEVEL CONVERGENCE
NORTH OF STATIONARY BOUNDARY FARTHER SOUTH. OTHERWISE...FOCUS ON
INTENSE LOW PRESSURE EXPECTED TO DEVELOP IN THE PLAINS ON TUE AND
MOVE ACROSS LOWER LK MI EARLY WED MRNG. STEEP LOW LEVEL LAPSE RATES
MAY ALLOW WIND GUSTS TO REACH 35KTS AS LOW DEEPENS TO THE SOUTH.
WINDS DIMINISH BRIEFLY BTWN 10Z AND 14Z WED AS LOW MOVES NEARS
REGION...BEFORE STRONG W TO NW WNDS RAPIDLY DEVELOP AS LOW MOVES
FARTHER NE. BETTER POTENTIAL FOR GALE WARNING CRITERIA TO BE MET
WED INTO WED NGT. WL POST GALE WATCH FROM TUE NGT THRU WED NGT AT
THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY
EVENING FOR WIZ046-047-051-052-056>060-062>072.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ052-
059-060.
LM...GALE WATCH FROM TUESDAY EVENING THROUGH LATE WEDNESDAY NIGHT
FOR LMZ643>646.
&&
$$
SHORT/LONG TERM...PC
AVIATION/MARINE...MBK
