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000
FXUS63 KMKX 071708 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1108 AM CST FRI MAR 7 2014

.UPDATE...
VIRGA SHOWING UP ON RADAR THIS MORNING IN SOUTHERN WISCONSIN WITH
A FEW SHOWERS REACHING THE GROUND UPSTREAM. LOWER LEVELS ARE
PRETTY DRY BUT A FEW LIGHT RAIN SHOWERS MAY BRUSH PARTS OF THE CWA
THIS AFTERNOON. THIS IS ASSOCIATED WITH A SURFACE TROUGH AND LOW
LEVEL FRONTOGENESIS EXPECTED TO MOVE ACROSS SOUTHERN IN THE
AFTERNOON. EXPECTING HIGH TEMPERATURES IN THE LOWER 40S. GFS IS
AN OUTLIER WITH GREATER PRECIPITATION DURING THIS TIME.

THERE IS BETTER AGREEMENT AMONG MODELS FOR SOME LIGHT POST-
FRONTAL PRECIPITATION AFTER 0Z...WINDING DOWN AROUND 12Z. A RAIN
SNOW MIX IS POSSIBLE DURING THE EVENING CHANGING TO LIGHT SNOW
OVERNIGHT.

&&

.AVIATION/18Z TAFS/...
VFR CONDITIONS WILL CONTINUE INTO THE AFTERNOON. A SHORTWAVE AND
COLD FRONT WILL BRING A CHANCE FOR RAIN AND SNOW SHOWERS MAINLY
DURING THE EVENING HOURS. SOME QUESTION AS TO PRECIP TYPE...WITH
MODEL SOUNDINGS RIGHT AT THE RAIN/SNOW THRESHOLD. EITHER
WAY...PRECIP AMOUNTS ARE EXPECTED TO BE LIGHT.

LOWER CIGS ARE EXPECTED AS THE FRONT/PRECIP MOVE THROUGH...AND THEN
BEHIND THE FRONT AS COLDER AIR MOVES IN. WILL LIKELY SEE A RETURN TO
VFR TOMORROW AS HIGH PRESSURE APPROACHES.

&&

.PREV DISCUSSION... /ISSUED 438 AM CST FRI MAR 7 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.

CURRENTLY WARM ADVECTION-FORCED AREA OF LIGHT MIXED PRECIPITATION IS
EASTWARD ACROSS NW WISCONSIN/NE MN. THERE IS A TRAILING NARROW
BROKEN BAND OF ANAFRONT-LIKE PCPN ALONG/BEHIND SURFACE COLD FRONT IN
REGION OF BEST 850-700MB FRONTOGENESIS STRETCHING BACK INTO CENTRAL
MN. A SECOND AREA OF LIGHT PCPN...WITH LITTLE IN THE WAY OF GROUND
TRUTH UNDER 6K-10K FT CEILINGS...OVER NW IA/SW MN WITH LOWER-LEVEL
WARM ADVECTION IS EXPECTED TO CROSS MAINLY CENTRAL WI LATER THIS
MORNING. HAVE ONLY SLIGHT CHANCE POPS FOR THIS AREA WITH ISENTROPIC
SURFACES SHOWING CONDENSATION PRESSURE DEFICITS OF 100 MB OR GREATER.

OUR BETTER CHANCE FOR PCPN COMES WITH THE SURFACE FRONT AND 850 MB
TROUGH THIS AFTERNOON AND EVENING. MODELS SIMILAR WITH TIMING OF
SURFACE TROUGH AND ASSOCIATED LOW-LEVEL CONVERGENCE AND MID
LEVEL TROUGH PASSAGE THROUGH REGION.

MAIN DIFFERENCE IS HOW NAM HAS BACKED WAY OFF ON PCPN...ESPECIALLY
FOR THIS EVENING. WILL TIME PCPN WITH BEST 850MB-700MB
FRONTOGENETIC FORCING...WHICH MOVES INTO NW CWA THIS AFTERNOON
AND ACROSS THE REST OF THE CWA THIS EVENING. EXCEPT FOR
GFS...DYNAMIC FORCING WEAK AS MAIN SHORT WAVE CROSSES TO THE NORTH
OF LK SUPERIOR.

PCPN TYPE WILL BE TRICKY...AS MODEL SOUNDINGS AND TOP DOWN METHOD
INDICATE A PERIOD OF A MIX OF SNOW...RAIN..SLEET AND FREEZING RAIN
LATE THIS MORNING INTO EARLY THIS AFTERNOON WITH ANY PCPN FROM THE
INITIAL WARM ADVECTION. SHOULD BE ALL RAIN WITH THE FRONT LATER THIS
AFTERNOON INTO THE EVENING WITH TEMPS APPROACHING 40 IN MANY
LOCATIONS. IN SPITE OF THE WARM TEMPERATURES COULD STILL BE SOME
FREEZING OF RAIN ON COLD ROAD SURFACES CHILLED BY DEEP FROST LAYER
UNDERNEATH.

RAISED POPS TOWARD THE IL BORDER THIS EVENING AS FRONT AND 850
TROUGH SLOW WITH A WEAK WAVE MOVING ACROSS REGION...WITH LIFT
ENHANCED BY UPPER LEVEL DIVERGENCE IN RIGHT-REAR QUADRANT OF 300 MB
KT MAX. COLUMN COLLAPSES FOR THE RAIN TO TURN TO A RAIN/SNOW
MIX...THEN ALL SNOW FROM NORTH TO SOUTH THROUGH THE EVENING THEN
ALL SNOW AFTER MIDNIGHT. SNOW TOTALS EXPECTED TO BE ONLY A FEW
TENTHS OF AN INCH.

SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE
IS HIGH.

LEFT LOW POPS FOR LIGHT SNOW IN THE FAR SOUTHEAST COUNTIES EARLY
SATURDAY MORNING...UNTIL COOLER AND DRIER AIR MOVES INTO THAT
AREA. HIGH PRESSURE THEN SLIDES EAST SOUTHEASTWARD TO THE SOUTH OF
THE AREA LATER SATURDAY INTO SATURDAY NIGHT. THIS WILL BRING QUIET
WEATHER TO THE AREA.

COLD TEMPERATURES RETURN BRIEFLY...WITH HIGHS SATURDAY IN THE
UPPER 20S. LOWS SATURDAY NIGHT DROP DOWN INTO THE SINGLE DIGITS
ABOVE ZERO ACROSS MOST OF THE AREA...A BIT WARMER NEAR THE
LAKESHORE.

AS THE HIGH SLIDES TO THE EAST SOUTHEAST SUNDAY...SOUTHWEST WINDS
WILL DEVELOP IN ITS WAKE. A FAIRLY TIGHT PRESSURE GRADIENT
DEVELOPS SUNDAY AND LINGERS INTO SUNDAY NIGHT. THE GFS IS THE ONLY
MODELS TO WEAKEN WINDS AND BRING A SURFACE TROUGH SOUTHEASTWARD
THROUGH THE AREA LATER SUNDAY NIGHT.

WENT WITH GFS/ECMWF/CANADIAN SOLUTIONS...WHICH BRING A GOOD SHOT
OF WARM AIR ADVECTION INTO THE AREA. THIS SHOULD BRING MILDER
TEMPERATURES INTO THE AREA...DESPITE THE DEEP SNOWPACK ON THE
GROUND. HIGHS SUNDAY SHOULD REACH THE MID TO UPPER 30S...WITH LOWS
ONLY DROPPING INTO THE UPPER 20S TO AROUND 30 SUNDAY NIGHT.

LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS
MEDIUM.

GFS AND ECMWF ARE SHOWING A FAIR AMOUNT OF DIFFERENCES WITH
FEATURES DURING THIS PERIOD. THE GFS CONTINUES THE WARM AIR
ADVECTION MONDAY...THEN BRINGS A COLD FRONT SOUTHWARD THROUGH THE
AREA MONDAY NIGHT AND TUESDAY. A 500 MB VORTICITY MAXIMUM ALSO
SLIDES SOUTH THROUGH THE AREA MAINLY TUESDAY NIGHT. THE GFS BRINGS
A DECENT AMOUNT OF QPF TO THE AREA MONDAY NIGHT INTO TUESDAY.

THE ECMWF ALSO HAS WARM AIR ADVECTION MONDAY...BUT KEEPS THE AREA
DRY WITH THE FRONTAL PASSAGE MONDAY NIGHT INTO TUESDAY. LEANED
TOWARD MODEL CONSENSUS POPS AND TEMPERATURES FOR THE MONDAY INTO
TUESDAY NIGHT PERIOD. HIGHS MONDAY SHOULD GET INTO THE MID 40S
ACROSS MOST OF THE AREA....WITH LOWS MONDAY NIGHT ONLY IN THE MID
TO UPPER 30S.

GFS/ECMWF THEN KEEP A STRONG LOW PRESSURE SYSTEM AND SUBSEQUENT
QPF SOUTH AND SOUTHEAST OF THE AREA WEDNESDAY INTO WEDNESDAY
NIGHT. NORTH WINDS SHOULD BRING COLDER TEMPERATURES BACK INTO THE
AREA.

AVIATION/12Z TAFS/...ADDED WIND SHEAR BACK INTO KMSN TAF UNTIL
MID-MORNING AS WINDS AHEAD OF APPROACHING TROUGH UP TO 35-40KT
AROUND 1300 TO 1400 FT ON AREA WIND PROFILERS MATCHING UP WELL
WITH STRONGER 925MB FORECAST WINDS. WILL LEAVE OUT OF OTHER SITES
AS THEY FALL JUST TO THE SOUTHEAST OF THE STRONGER WINDS JUST OFF
THE DECK AND NEVER REACH CRITERIA...THOUGH THEY WILL JUMP UP TO
20-25 KNOTS WITHIN 1K FT OF THE SURFACE.

VFR CONDITIONS EXPECTED UNTIL LATE THIS AFTERNOON. THERE IS A
VERY LOW CHANCE OF SOME MIXED PRECIPITATION TO REACH KMSN LATE
THIS MORNING/EARLY THIS AFTERNOON...BUT THE BETTER CHANCE FOR ALL
TAF SITES WILL BE LATE THIS AFTERNOON AND EVENING.

ONLY MVFR CIGS/VSBYS WITH THE PRECIPITATION AS IT WILL BE LIGHT.
EXPECT ALL RAIN TO START...THEN MIXING WITH SNOW EARLY IN THE
EVENING. THE MIX CHANGES TO ALL SNOW AT KMSN LATE EVENING...AND
AFTER MIDNIGHT AT THE REMAINING TAF SITES. SNOW AMOUNTS OF ONLY A
FEW TENTHS OF AN INCH EXPECTED. COLD ADVECTION AND LOW-LEVEL
MOISTURE KEEPS MVFR CIGS UNTIL END OF FORECAST.

MARINE...SOUTH TO SOUTHWEST WINDS WILL GUST TO 20 KNOTS...WITH A
FEW GUSTS OF 22 TO 25 KTS THIS MORNING...BUT NOT FREQUENT ENOUGH
FOR A HEADLINE. WINDS EASE LATE THIS MORNING/EARLY THIS AFTERNOON AHEAD
OF COLD FRONT...THEN TURN NORTHWEST AND THEN NORTH BEHIND THE
FRONT. WIND GUSTS WILL APPROACH SMALL CRAFT CRITERIA AGAIN
OVERNIGHT INTO SATURDAY...BUT LOW CONFIDENCE THEY WILL BE FREQUENT
ENOUGH FOR A HEADLINE.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

UPDATE...SM/DDV
TODAY/TONIGHT AND AVIATION/MARINE...REM
SATURDAY THROUGH THURSDAY...WOOD