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000
FXUS63 KMKX 041855 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1255 PM CST TUE MAR 4 2014

.UPDATE...

SNOW TAPERED OFF QUICKLY THIS MORNING. LINGERING 5000 FT CLOUDS
ALLOWING FOR A FEW FLURRIES THROUGH EARLY AFTERNOON. THERE ARE SOME
BREAKS IN THE CLOUDS OVER SOUTHWEST WISCONSIN DUE TO SOME LOW LEVEL
DRY AIR...BUT OTHERWISE SKIES WILL BE CLOUDY THROUGH THE REST OF
THE DAY. MAX TEMPS IN THE LOWER 20S SEEM ON TRACK.

THE 06Z AND 12Z NAM AND GFS MODELS AND NOW THE 12Z CANADIAN AND
ECMWF MODELS CAME IN WITH HIGHER QPF AMOUNTS OVER SOUTHERN WI FOR
TONIGHT/S CLIPPER SYSTEM. TOOK A BLEND OF THESE VALUES FOR
PRELIMINARY SNOWFALL TOTALS. EXPECTING THIS EVENT TO HAVE A BANDED
STRUCTURE THAT COULD PUT DOWN 3-5 INCHES OVER A SMALL AREA. IN
ADDITION...THE HIGHEST OMEGA WILL BE OVER SOUTH CENTRAL WI EARLY IN
THE EVENT AND THEN SHIFT SOUTH LATER IN THE EVENT.

IT IS IMPOSSIBLE TO PIN DOWN EXACTLY WHERE THAT BAND WOULD SET
UP...BUT I FACTORED IN A TIGHTER QPF GRADIENT SOUTHWEST OF MADISON
AS A FIRST GUESS. THEREFORE...ISSUED A WINTER WEATHER ADVISORY FOR
IOWA...LAFAYETTE AND GREEN COUNTIES FOR TONIGHT AND LEFT OUT DANE
AND ROCK COUNTIES FOR NOW.

SNOW WILL TAPER OFF FROM WEST TO EAST WED MORNING FROM 5 AM THROUGH
9 AM. EXPECTING SNOW TO STILL BE FALLING IN THE MILWAUKEE/KENOSHA
AREA THROUGH THE MORNING RUSH HOUR...SO EXPECT A ROUGH COMMUTE.

&&

.AVIATION/18Z TAFS/...

VFR CIGS UNTIL LATE EVENING AS ANOTHER CLIPPER SYSTEM ARRIVES. WINDS
WILL BE LIGHT AND VARIABLE THROUGH MID EVENING AND THEN BECOME
NORTHEAST TO EAST DURING SNOW THROUGH WEDNESDAY MORNING. EASTERLY
WINDS WILL INCREASE ONCE THE SNOW ENDS BY LATE MORNING.

SNOW WILL GRADUALLY SPREAD EASTWARD INTO THE AREA LATE THIS EVENING.
A 2 TO 4 HOUR PERIOD OF MODERATE SNOW WITH 1/2 TO 1 MILE VSBU AND
IFR CIGS IS EXPECTED AROUND MIDNIGHT NEAR MSN AND AROUND MILWAUKEE
NEAR 3 AM. SNOW WILL TAPER OFF FROM WEST TO EAST WED MORNING FROM 5
AM THROUGH 9 AM.

&&

.PREV DISCUSSION... /ISSUED 427 AM CST TUE MAR 4 2014/

TODAY...FORECAST CONFIDENCE HIGH.

LIGHT TO MODERATE SNOW WITH WAA AHEAD OF SHORT WAVE THAT TRACKS EAST
WITH UPPER LEVEL DIVERGENCE OVER SRN WI IN RRQ OF UPPER JET MAX THAT
SHIFTS EAST OF AREA BY 12Z. THE SNOW IS EXPECTED TO CLEAR LOCATIONS
FROM MILWAUKEE SOUTH BY 8 AM...BUT VERY LIGHT SNOW/FLURRIES WILL
LINGER OVER THE NORTHEAST THIRD TO HALF OF THE FORECAST AREA WITH
FORCING AS SECOND WAVE PASSES ACROSS THE STATE BETWEEN 12Z AND 18Z.

MOSTLY CLOUDY SKIES TODAY...BUT WARM ADVECTION RAISES 925MB TEMPS
ENOUGH TO SEE HIGHS IN THE LOW TO MID 20S OVER MOST OF THE
CWA...WITH AROUND 20 IN THE NORTHEAST.

TONIGHT...FORECAST CONFIDENCE MEDIUM

NEXT ROUND OF SNOW EXPECTED BY THIS EVENING AS ANOTHER CLIPPER WAVE
IN ULD WITH LFQ OF NEXT JETLET THAT CROSSES REGION BETWEEN 00Z AND
06Z WED. BEST LAYER Q-VECTOR CONVERGENCE AND COLUMN SATURATION OVER
THE SW 2/3 OF CWA...SO WILL GO WITH CATEGORICAL POPS THERE TAPERING
OFF RAPIDLY TO CHANCE POPS IN THE NE THIRD. 06Z NAM SIMILAR TO 00Z
RUN IN MAINTAINING AN 8 TO 10 MICROBAR/SEC OMEGA MAX IN THE DENDRITE
GROWTH ZONE OVER THE SW CWA...BUT HAS BOOSTED QPF UP TO 0.20 INCH.
MODEST LAPSE RATES AROUND 600 MB STEEPEN ABOVE 500 MB...BUT
INGREDIENTS PLOTS INDICATE BETTER CHANCE FOR CONVECTIVE SNOWS WILL
BE SOUTHWEST OF CWA. UPPED QPF AND SNOW AMOUNTS IN THE SOUTHWEST TO
AROUND 3 INCHES...WITH LATER SHIFTS NEEDING TO ASSES THE NEED FOR AN
ADVISORY.

WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM

MAY SEE A LITTLE SNOW HANG ON WEDNESDAY MORNING AS THE SHORTWAVE
EXITS THE AREA. SHOULD BE MAINLY DRY FOR THE AFTERNOON...WITH
HIGHS REMAINING WELL BELOW NORMAL FOR EARLY MARCH.

ANOTHER SHORTWAVE WILL PUSH THROUGH WEDNESDAY EVENING/NIGHT...BUT
KEPT THE FORECAST DRY MOST PLACES AS SOUNDINGS SHOW A LOT OF DRY
AIR IN THE LOW LEVELS. DID KEEP SOME SMALL POPS NEAR THE LAKE
THOUGH...AS SOUTHEAST WINDS MAY BRING A FEW LAKE EFFECT SNOW
SHOWERS. GIVEN MUCH OF THE LAKE IS COVERED IN ICE THOUGH...AND
SFC TO 850 MB DELTA T VALUES ARE AROUND 10 DEGREES AT
BEST...CONFIDENCE IS PRETTY LOW IN ANY LAKE EFFECT SNOW.

SOUTHERLY WINDS AND INCREASING WARM ADVECTION ALOFT THURSDAY
SHOULD PUSH TEMPS INTO THE UPPER 20S...THOUGH STILL QUITE A FEW
DEGREES BELOW NORMAL. MOST OF THE MODELS HOLD OFF ANY PRECIP UNTIL
THURSDAY EVENING/NIGHT INTO FRIDAY. WITH INCREASING TEMPS AT THE
SFC AND ALOFT...LOOKS LIKE A MIX OF PRECIP POSSIBLE FOR THIS
SHORTWAVE. CURRENT MODEL SOUNDINGS SUGGEST SNOW OR SLEET THURSDAY
NIGHT...WITH SNOW/SLEET/RAIN ALL POSSIBLE FRIDAY AS TEMPERATURES
WARM INTO THE 30S. PRECIP AMOUNTS LOOK GENERALLY LIGHT THROUGH THE
EVENT.

SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM

HIGH PRESSURE WILL SLIDE THROUGH THE AREA OVER THE
WEEKEND...BRINGING SOME DRY WEATHER AND SUNSHINE. THE BIGGEST
ISSUE FOR THIS PERIOD IS THE STRENGTH OF THE HIGH AND IMPACT ON
TEMPERATURES. THE GFS HAS A STRONGER HIGH THAN THE ECMWF AND
CANADIAN...ALLOWING FOR A SLOWER RETURN OF MILDER TEMPS. GENERALLY
SPLIT THE DIFFERENCE FOR HIGHS SUNDAY...AS THE GFS SUGGESTS TEMPS
STRUGGLING TO THE LOW 20S...WHILE THE ECMWF AND CANADIAN ARE
PUSHING 40.

MODELS ARE HINTING AT A LITTLE PRECIP MONDAY...SO WENT WITH SOME
LOW POPS FOR RAIN/SNOW. GFS FINALLY HAS THE MILDER AIR INTO
WISCONSIN BY MONDAY...SO BETTER CONFIDENCE IN NEAR NORMAL TEMPS.

AVIATION/12Z TAFS... THE BAND OF MODERATE TO HEAVY SNOW WITH LIFR
CIGS/VSBYS WILL EXIT EASTERN WI BY 11Z. THE BACK EDGE OF THE BROADER
AREA OF LIGHT TO MODERATE SNOW WITH MVFR/IFR CIGS AND VSBYS IS AT
THE MS RIVER AT 10Z AND WILL BE REACHING KMSN BY 12Z...KUES
AROUND 1330Z...KENW BY 14Z AND KMKE BETWEEN 14Z AND 1430Z. CIGS
WILL RAPIDLY RAISE TO BETWEEN 4K FT AND 6K FT BEHIND THE SNOW.

WATCHING LIGHT SNOW OVER SE MN INTO W CENTRAL WI WITH A SECOND
WAVE THAT HI-RES/RAPID UPDATE MODELS HAD BEEN KEEPING NORTH OF TAF
SITES. 09Z RAP NOW BRINGING A SMALL POCKET OF SNOW TO KMSN BY 15Z
AND THROUGH KUES AND KMKE BETWEEN 15Z AND 18Z. WILL MONITOR TRENDS
AND ADJUST AS NEED AT ISSUANCE.

NEXT ROUND OF SNOW COMES THIS EVENING WITH NEXT SHORT WAVE. 00Z
MODELS INDICATING MVFR CIGS/VSBYS...WITH BRIEF IFR VSBYS...WITH 1
TO 1.5 INCHES OF SNOW FOR EASTERN TAF SITES AND 1.5 TO 2 INCHES
FOR KMSN TONIGHT. 06Z NAM TRYING TO SHOW POTENTIAL FOR MORE SNOW
OVER THE SW CWA THAT COULD EDGE TOWARDS KMSN BUT WILL AWAIT LATER
RUNS BEFORE RAISING AMOUNTS/LOWERING CONDITIONS

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
     WEDNESDAY FOR WIZ062-067-068.

LM...NONE.
&&

$$

UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...DDV