Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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000
FXUS63 KMKX 010942
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
342 AM CST MON FEB 1 2016

.SHORT TERM...

TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.

THE UPPER FLOW BECOMES MORE WEST SOUTHWEST AS THE UPPER TROUGH OVER
THE ROCKIES PUSHES SLOWLY EAST.  UPPER LEVEL DIVERGENCE INCREASES
AFTER MIDNIGHT ALONG WITH 700 MB UPWARD MOTION.  700 MB UPWARD
MOTION BECOMES QUITE STRONG OVER THE ILLINOIS BORDER AREA OF
SOUTH CENTRAL WISCONSIN TOWARD SUNRISE.

700 MB RH DRIES TODAY...BUT THEN QUICKLY SATURATES LATE TONIGHT.  A
50 KNOT 700 MB JET MOVES INTO THE FAR SOUTH LATE TONIGHT.  THE
RESULTING MOISTURE CONVERGENCE SHOULD SPREAD SNOW INTO THE FAR
SOUTH.  AS SUCH WILL HAVE TO START THE WINTER HEADLINES A LITTLE
QUICKER IN THE FAR SOUTHWEST.

THE MAIN FORECAST PROBLEM THIS MORNING WILL BE FOG/STRATUS
CONCERNS...ESPECIALLY SOUTH CENTRAL AND HOW QUICK THE STRATUS
DISSIPATES.

TUESDAY AND TUESDAY NIGHT... FORECAST CONFIDENCE MEDIUM.

THE 00Z RUNS OF THE GFS AND ECMWF FINALLY CAME INTO AGREEMENT WITH
THE TRACK OF THE SURFACE LOW. THE NAM IS THE OUTLIER. THEY TAKE IT
FROM THE KS/NE/MO BORDER AT 18Z TUE TO THE MO/IA/IL BORDER AT 00Z
WED... AND TO CENTRAL LAKE MICHIGAN AT 06Z WED. THE TRACK OF THE
700MB LOW IS JUST TO THE NW OF THE SFC LOW AND SLIDES ACROSS CENTRAL
IOWA TUE AFTERNOON AND DIAGONALLY THROUGH CENTRAL WI TUE EVENING.
THE 850MB LOW IS RIGHT IN BETWEEN. THE AXIS OF HEAVIEST SNOW WILL BE
ALONG THE 700MB LOW TRACK AND COINCIDENT BAROCLINIC ZONE.

A E-W ORIENTED BAND OF STRONG 700MB FRONTOGENESIS WILL SLIDE
NORTHWARD ACROSS SOUTHERN WI TUE MORNING FROM 09Z TO 18Z. THERMAL
PROFILES SUGGEST ALL SNOW WITH THIS INITIAL BAND... EVEN IN SOUTHEAST
WI. THERE IS A LITTLE DRY AIR TO OVERCOME DURING THE ONSET OF THE
SNOW... BUT IT IS CHARACTERISTIC FOR STRONG FGEN TO WIN IN THESE
SITUATIONS. SNOWFALL RATES COULD BE QUITE HIGH WITHIN THIS BAND DUE
TO THE VERY STRONG UPWARD MOTION WITHIN THE DENDRITE GROWTH ZONE
/DGZ/ THAT COULD BE FAIRLY DEEP FOR A SHORT PERIOD OF TIME. DEBATED
ABOUT INCLUDING THE SOUTHEAST COUNTIES IN THE ADVISORY TO ACCOUNT
FOR THIS BAND. GIVEN TOTAL SNOWFALL AMOUNTS OPTED TO KEEP THEM OUT
FOR NOW... BUT CAUTION IS ADVISED DUE TO IMPACTS ON TUESDAY MORNING
COMMUTE.

THE DRY SLOT WILL MAKE ITS WAY INTO SOUTH CENTRAL WI AROUND 21Z TUE
AND INTO SOUTHEAST/ EAST CENTRAL WI BY 00Z WED. THIS IS GOING TO
DIMINISH THE PRECIP QUITE A BIT. THE ONLY EXCEPTION IS TOWARD
CENTRAL WI NEAR THE CENTER OF THE 700MB LOW. THAT 700MB FGEN BAND
WILL PIVOT OVER CENTRAL WI AND KEEP THE SNOW GOING THROUGH THE DAY
AND INTO THE EVENING. SO OUR MAIN EVENT FOR ALL BUT THE FAR W/NW
COUNTIES IN THE MKX COUNTY WARNING AREA /CWA/ WILL OCCUR DURING THE
DAYLIGHT HOURS FRIDAY.

THIS BRINGS US TO SURFACE TEMPERATURES. I UNDERCUT BLENDED GUIDANCE
FOR TEMPS TO ACCOUNT FOR DYNAMIC COOLING... ESPECIALLY TUE MORNING
AND IN THE WESTERN CWA TUESDAY AFTERNOON. THE GFS IS SHOWING WARM
AIR ALOFT BETWEEN 750 AND 850MB AND A COLD LAYER BENEATH THAT MIDDAY
TUESDAY. THIS WOULD MEAN A DECENT POTENTIAL FOR SLEET ALL THE WAY
INLAND TO MADISON. BY 00Z AFTER THE DRY SLOT GETS IN... TEMPERATURES
BELOW 5000 FT WARM ABOVE FREEZING... INCLUDING MADISON.  THIS MEANS
MUCH OF OUR AREA WILL HAVE RAIN/DRIZZLE EARLY TUE EVENING UNTIL THE
DEFORMATION ZONE CAN SLIDE ACROSS AND SATURATE UP TO THE DGZ TO
BRING SNOW SHOWER CHANCES THROUGH THE REST OF THE NIGHT.

UPGRADED THE WINTER STORM WATCH TO A WARNING AND ADDED SHEBOYGAN
COUNTY TO THAT. MADISON CITY AMOUNTS ARE STILL UNCERTAIN DUE TO THE
WARM AIR WRAPPING INTO SOUTH CENTRAL WI... BUT NORTHWEST OF THERE I
HAVE HIGHER CONFIDENCE IN MEETING WARNING CRITERIA.

.LONG TERM...

WEDNESDAY... FORECAST CONFIDENCE MEDIUM.

MOISTURE WILL BE SHALLOW IN THE WAKE OF THIS SYSTEM... ALTHOUGH
ECMWF IS SHOWING JUST A LITTLE MORE QPF THAN GFS ON WED.
TEMPERATURES ALOFT WILL BE COOLING AND WHAT SHALLOW MOISTURE IS LEFT
COULD REACH THE DGZ SO KEPT CHANCE FOR SNOW SHOWERS ACROSS SOUTHERN
WI THROUGH THE DAY. BY WED NIGHT... WEAK SFC RIDGE MOVES IN AND
LIMITS SNOW POTENTIAL. CLEAR SKIES AND LIGHT WINDS SHOULD ALLOW
TEMPS TO DROP INTO THE SINGLE DIGITS AND LOWER TEENS.

THURSDAY AND FRIDAY... FORECAST CONFIDENCE MEDIUM.

FORECAST IS DRY FOR THU IS DRY ALTHOUGH A WEAK TROUGH MOVING THROUGH
COULD BRING MORE CLOUDS. FRIDAY NIGHT IS OUR NEXT TIME FOR LIGHT
SNOW CHANCES WITH POTENT UPPER TROUGH.

SATURDAY THROUGH MONDAY... FORECAST CONFIDENCE MEDIUM.

LIGHT SNOW CHANCES COULD LINGER ALONG A COLD FRONT DRAPED ACROSS
CENTRAL WI. HOWEVER THE ECMWF SUGGESTS A DRIER AND WARMER SOLUTION.

&&

.AVIATION/12Z TAFS/...

MVFR/IFR CIGS/VSBYS ALONG WITH SOME LIFR WILL BECOME MORE WIDESPREAD
THIS MORNING...ESPECIALLY OVER SOUTH CENTRAL WISCONSIN.  MUCH OF ANY
STRATUS IS EXPECTED TO SLOWLY LIFT DURING THE AFTERNOON AND EVENING.

THEN EXPECT IFR CIGS/VSBYS TO SPREAD INTO THE SOUTH...ESPECIALLY OVER
SOUTH CENTRAL WISCONSIN LATE TONIGHT AND TOWARDS SUNRISE AS A 50
KNOT 700 MB LOW LEVEL JET PUSHES NORTH AHEAD OF THE APPROACHING LOW
OVER EASTERN KANSAS.

&&

.MARINE...

GUSTY ONSHORE WINDS ARE EXPECTED TUESDAY INTO TUESDAY EVENING...AS A
STRONG LOW PRESSURE SYSTEM EXITS EASTERN KANSAS AND MOVES TOWARD
NORTHERN ILLINOIS AND FAR SOUTHEAST WISCONSIN.

THE STRONG WINDS WILL BECOME NORTHWEST LATER TUESDAY NIGHT INTO
WEDNESDAY...AS THE LOW MOVES NORTHEAST AWAY FROM THE AREA.

A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR TUESDAY INTO
WEDNESDAY OR WEDNESDAY NIGHT IN LATER FORECASTS. GALE FORCE GUSTS
MAY OCCUR AT TIMES ON TUESDAY AND LATE TUESDAY NIGHT AS WELL. FOR
NOW WILL GO WITH A GALE WATCH FOR THE EAST WINDS AHEAD OF THE STRONG
LOW.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR WIZ059-
     060-064-065-068-069.

     WINTER STORM WARNING FROM 6 AM TUESDAY TO 6 AM CST WEDNESDAY FOR
     WIZ046-047-051-052-056>058-062-063.

     WINTER STORM WARNING FROM 4 AM TUESDAY TO 3 AM CST WEDNESDAY FOR
     WIZ067.

LM...GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR
     LMZ643>646.

&&

$$

TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
TUESDAY THROUGH SUNDAY...MRC


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