Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 070337
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
937 PM CST SAT FEB 6 2016

.UPDATE...EARLY EVENING CLEARING ALLOWED TEMPERATURES TO PLUMMET
INTO THE MID TO UPPER 20S. TEMPS HOWEVER HAVE STABILIZED SOMEWHAT
AS THE LOW LEVEL WINDS BEGIN TO INCREASE AND UPSTREAM MID/HIGH
CLOUDS FROM WARM AIR ADVECTION SPREAD ACROSS THE AREA. LOW
DEWPOINT DEPRESSIONS WL LIKELY ALLOW PATCHY LIGHT FOG BUT CLOUDS
AND INCREASING BOUNDARY LAYER WINDS SHOULD PREVENT FOG FROM
BECOMING MORE WIDESPREAD. HENCE WL NOT INCLUDE AT THIS TIME. ALSO
REMOVED FLURRIES THROUGH 06Z BUT LEFT SMALL POPS IN FOR LATE
TONIGHT ACROSS THE NORTH. COLUMN LAYER MOISTURE APPEARS DISJOINTED
BUT WL POINT OUT TO NEXT SHIFT STRONG UPSTREAM SHORT WAVE TROF
CURRENTLY OVER EASTERN DAKOTAS WHICH WILL BE MOVING RAPIDLY ACROSS
SRN WI SUNDAY MRNG. POSSIBLE ISOLD -SHRA/-SHSN COULD ACCOMPANY
THIS TROF. PERIODS OF -SHSN LOOKING LIKELY FROM LATER SUNDAY NIGHT
INTO MONDAY NIGHT AS LONG WAVE TROF INCREASES IN COVERAGE AND
AMPLITUDE ACROSS THE GREAT LAKES AND ADJOINING AREAS.


&&

.AVIATION/06Z TAFS/...PATCHY MVFR CIGS DEVELOPED SOUTHWEST OF
MADISON EARLIER THIS EVENING. THIS AREA HAS ERODED WHILE MOVING
EAST INTO DRIER AIR. UPSTREAM AREA OF MVFR CIGS OVER NE IOWA/SW
MINNESOTA ALSO APPEARING LESS SUBSTANTIAL AS IT PROGRESSES TOWARDS
US. WHILE THERE IS A LOWER CLOUD DECK UPSTREAM AROUND 1 TO 1.5
KFT...IT/S LARGELY REMAINED SCT TO OCCASIONALLY BKN DURING THE
PAST HOUR OR SO. CURRENT THINKING IS TO KEEP A VFR FORECAST FOR
TONIGHT AND TO HANDLE ANY LOWER CIGS WITH TEMPOS AS NEEDED. DID
KEEP SOME SCT AT 1.5 KFT AT THE EASTERN TAF SITES TO ADVERTISE THE
LOWER CLOUD POTENTIAL. FLURRIES ARE POSSIBLE OVERNIGHT IN WARM
ADVECTION REGIME PRECEDING A LOW PRESSURE TROUGH. POTENTIAL FOR
LOW-LEVEL WIND SHEAR LATE TONIGHT TOWARDS MORNING AS A 35-40 KT
LOW-LEVEL JET CROSSES SOUTHERN WISCONSIN. LIGHT ACCUMULATING SNOW
IS EXPECTED LATE SUNDAY EVENING INTO MONDAY.

&&

.MARINE...TIGHTENING PRESSURE GRADIENT EXPECTED THROUGH THE LATE
NIGHT ACROSS LAKE MICHIGAN AS LOW PRESSURE MOVES TOWARD LAKE
SUPERIOR FROM JUST NORTH OF THE DAKOTAS. WINDS WILL REMAIN
SOUTHWEST AND A FEW GUSTS WILL LIKELY REACH 22-25 KNOTS...ESPECIALLY
AWAY FROM SHORE. HOWEVER COOL LAKE MICHIGAN SURFACE TEMPERATURE
AROUND 35F AND STRONG INVERSION WILL PREVENT FREQUENT GUSTS ABOVE
22 KNOTS LATER TONIGHT INTO MONDAY. HENCE WL HOLD OFF ON ISSUING
SMALL CRAFT ADVISORY AT THIS TIME DUE TO BORDERLINE SITUATION AND
MINIMAL LAKE TRAFFIC. DIFFERENT STORY LATER MONDAY INTO TUESDAY
WHEN BLUSTERY NORTHWEST WINDS WL LIKELY REACH SMALL CRAFT
THRESHOLD BEHIND THE DEPARTING LOW PRESSURE.

&&

.PREV DISCUSSION... /ISSUED 145 PM CST SAT FEB 6 2016/

SHORT TERM...

TONIGHT AND SUNDAY...FORECAST CONFIDENCE...HIGH

A WEAK WAVE MOST NOTABLE FROM THE SURFACE TO 850 MB WILL MOVE
THROUGH TONIGHT...WITH A STRONGER UPPER LEVEL TROUGH MOVING INTO
SOUTHERN WISCONSIN BY LATE SUNDAY EVENING.

WILL SEE A GOOD SHOT OF 850 TO 700 MB WARM AIR ADVECTION THIS
EVENING AND OVERNIGHT. MOISTURE IS VERY LACKING IN THE LOWER LEVELS
TONIGHT...SO JUST WENT WITH MAINLY SCATTERED FLURRIES. COULD SEE
SOME HIGHER REFLECTIVITIES SKIM THE NORTH LATE TONIGHT INTO EARLY
SUNDAY MORNING...SO KEPT SOME LOW POPS IN THERE. SNOW MAY MIX WITH
RAIN TOMORROW MORNING.

LOOKS DRY THEN FROM MID SUNDAY MORNING THROUGH EARLY AFTERNOON AS
DEEPER MID LEVEL MOISTURE EXITS TO THE EAST. DEEPER MOISTURE RETURNS
WEST IN THE LATE AFTERNOON...SO BROUGHT POPS BACK INTO THE WEST.

CLOUDS ARE EXPECTED TO LINGER TONIGHT AND COMBINE WITH WARM
ADVECTION TO PRODUCE ABOVE NORMAL LOW TEMPS IN THE UPPER 20S AND LOW
30S. KEPT HIGH TEMPS CLOSER TO CANADIAN TOMORROW...AS IT IS DOING
THE BEST TODAY...A NICE COMPROMISE BETWEEN COOLER GFS/NAM AND MILDER
ECMWF.

SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE...HIGH

THE AN UPPER LEVEL SHORTWAVE MOVES ACROSS WISCONSIN SUNDAY NIGHT
WITH THE TROUGH AXIS OVER LOWER MICHIGAN BY NOON MONDAY. THE
TROUGH AT 500 MB BECOMES A BROAD CLOSED LOW THAT DROPS SOUTH ACROSS
WISCONSIN AND LAKE MICHIGAN SUNDAY NIGHT AND OVER LOWER MICHIGAN
MONDAY. BANDS OF MODERATE 700 MB UPWARD MOTION MOVE ACROSS
SOUTHERN WISCONSIN DURING THE PERIOD WITH PERSISTENT WEAK UPPER
DIVERGENCE.

THE SURFACE LOW BECOMES STACKED WITH THE MID LEVEL LOW AND DROPS
SOUTH ACROSS THE LAKE MICHIGAN AREA.  THE LOW AND MID LEVELS
SATURATE AND COOL. 850 MB TEMPERATURES ARE COOLER THAN -5 CELSIUS
AND SUPPORT SNOW...AND LAPSE RATES INCREASE WITH NEAR SATURATED
LOWER AND MID LEVELS. MID LEVEL LAPSE RATES ARE NEAR 7 CELSIUS/KM.

SNOWFALL GENERALLY LOOKS LIKE TOTALS OF AROUND 1 TO 2 INCHES
WOULD BE POSSIBLE GIVEN THE CURRENT MODEL OUTPUT.

MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE...HIGH

THE UPPER TROUGH REACHES THE EASTERN GREAT LAKES TUESDAY WITH A
WEAKLY CYCLONIC NORTHWEST FLOW INTO TUESDAY WITH WEAK 700 MB
UPWARD MOTION.

THE MID LEVELS BEGIN TO DRY...BUT REMAIN MOIST IN THE 925/850 MB
LAYER.

COULD SEE A LITTLE LIGHT SNOW LINGER INTO TUESDAY MORNING... WITH
FLURRIES POSSIBLE WEST AREAS ESPECIALLY EAST AS THE LOW SLOWLY
PULLS AWAY.

COLD AIR ADVECTION CONTINUES AT 850 MB...DROPPING TO AROUND MINUS
18 CELSIUS TUESDAY AFTERNOON.

LONG TERM...

TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE...HIGH

A NORTHWEST UPPER LEVEL FLOW CONTINUES WITH A SHEARED CYCLONIC
VORTICITY MAXIMUM MOVING ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY LATER WEDNESDAY.

MAINLY DRY WEATHER IS EXPECTED WEDNESDAY AS A SURFACE HIGH
PRESSURE RIDGE EARLIER CLEARING ALLOWED PATCHY MVFR CIGS
SOUTHWEST OF MADISON THIS EVENING. THIS AREA HAS ERODED WHILE
MOVING EAST INTO DRIER AIR. UPSTREAM AREA OF MVFR CIGS OVER NE
IOWA/SW MINNESOTA ALSO APPEARING LESS SUBSTANTIAL AS IT PROGRESSES
TOWARDS US. WHILE THERE IS A LOWER CLOUD DECK UPSTREAM AROUND 1 TO
1.5 KFT...IT/S LARGELY REMAINED SCT TO OCCASIONALLY BKN DURING THE
PAST HOUR OR SO. CURRENT THINKING IS TO KEEP A VFR FORECAST FOR
TONIGHT AND TO HANDLE ANY LOWER CIGS WITH TEMPOS AS NEEDED. DID
KEEP SOME SCT AT 1.5 KFT AT THE EASTERN TAF SITES TO ADVERTISE THE
LOWER CLOUD POTENTIAL. FLURRIES ARE POSSIBLE OVERNIGHT IN WARM
ADVECTION REGIME PRECEDING A LOW PRESSURE TROUGH. POTENTIAL FOR
LOW-LEVEL WIND SHEAR LATE TONIGHT TOWARDS MORNING AS A 35-40 KT
LOW-LEVEL JET CROSSES SOUTHERN WISCONSIN. LIGHT ACCUMULATING SNOW
IS EXPECTED LATE SUNDAY EVENING INTO MONDAY. MOVES INTO THE UPPER
MISSISSIPPI VALLEY. THE 00Z ECMWF DOES BRING SOME LIGHT SNOW
ACROSS A STRONG BAROCLINIC ZONE ACROSS EASTERN IOWA...BARELY
REACHING AREAS SOUTHWEST OF MADISON WEDNESDAY AFTERNOON. PREFER
THE DRY 12Z GFS AND 06Z DGEX...AND NOW THE 12Z ECMWF IS MORE LIKEL
THE GFS.

THURSDAY AND FEARLIER CLEARING ALLOWED PATCHY MVFR CIGS SOUTHWEST OF
MADISON THIS EVENING. THIS AREA HAS ERODED WHILE MOVING EAST INTO
DRIER AIR. UPSTREAM AREA OF MVFR CIGS OVER NE IOWA/SW MINNESOTA
ALSO APPEARING LESS SUBSTANTIAL AS IT PROGRESSES TOWARDS US. WHILE
THERE IS A LOWER CLOUD DECK UPSTREAM AROUND 1 TO 1.5 KFT...IT/S
LARGELY REMAINED SCT TO OCCASIONALLY BKN DURING THE PAST HOUR OR
SO. CURRENT THINKING IS TO KEEP A VFR FORECAST FOR TONIGHT AND TO
HANDLE ANY LOWER CIGS WITH TEMPOS AS NEEDED. DID KEEP SOME SCT AT
1.5 KFT AT THE EASTERN TAF SITES TO ADVERTISE THE LOWER CLOUD
POTENTIAL. FLURRIES ARE POSSIBLE OVERNIGHT IN WARM ADVECTION
REGIME PRECEDING A LOW PRESSURE TROUGH. POTENTIAL FOR LOW-LEVEL
WIND SHEAR LATE TONIGHT TOWARDS MORNING AS A 35-40 KT LOW-LEVEL
JET CROSSES SOUTHERN WISCONSIN. LIGHT ACCUMULATING SNOW IS
EXPECTED LATE SUNDAY EVENING INTO MONDAY.RIDAY...FORECAST
CONFIDENCE...MEDIUM

THE UPPER LEVEL FLOW BECOMES A LITTLE MORE ZONAL THURSDAY AS AN
UPPER LEVEL SHORTWAVE MOVES ACROSS CENTRAL TO SOUTHEAST CANADA IN
THE NORTHERN TROUGH WITH A WEAK SHORTWAVE MOVING ACROSS EASTERN
NEBRASKA AND INTO MISSOURI.

A WEAK SURFACE LOW MOVES ACROSS THE UPPER GREAT LAKES. WITH THE
SURFACE HIGH RIDGE AXIS ACROSS WESTERN WISCONSIN BY FRIDAY.

SATURDAY....FORECAST CONFIDENCE...MEDIUM

AN UPPER LEVEL RIDGE BUILDS ACROSS THE NORTHERN ROCKIES WITH A
NORTHWEST FLOW AGAIN ACROSS WISCONSIN.

A STRONG SURFACE HIGH EXTENDS ACROSS THE WESTERN GREAT LAKES
SATURDAY. EARLIER CLEARING ALLOWED PATCHY MVFR CIGS SOUTHWEST OF
MADISON THIS EVENING. THIS AREA HAS ERODED WHILE MOVING EAST INTO
DRIER AIR. UPSTREAM AREA OF MVFR CIGS OVER NE IOWA/SW MINNESOTA
ALSO APPEARING LESS SUBSTANTIAL AS IT PROGRESSES TOWARDS US. WHILE
THERE IS A LOWER CLOUD DECK UPSTREAM AROUND 1 TO 1.5 KFT...IT/S
LARGELY REMAINED SCT TO OCCASIONALLY BKN DURING THE PAST HOUR OR
SO. CURRENT THINKING IS TO KEEP A VFR FORECAST FOR TONIGHT AND TO
HANDLE ANY LOWER CIGS WITH TEMPOS AS NEEDED. DID KEEP SOME SCT AT
1.5 KFT AT THE EASTERN TAF SITES TO ADVERTISE THE LOWER CLOUD
POTENTIAL. FLURRIES ARE POSSIBLE OVERNIGHT IN WARM ADVECTION
REGIME PRECEDING A LOW PRESSURE TROUGH. POTENTIAL FOR LOW-LEVEL
WIND SHEAR LATE TONIGHT TOWARDS MORNING AS A 35-40 KT LOW-LEVEL
JET CROSSES SOUTHERN WISCONSIN. LIGHT ACCUMULATING SNOW IS
EXPECTED LATE SUNDAY EVENING INTO MONDAY.

AVIATION/00Z TAFS/...

MVFR CIGS WILL LIKELY HANG AROUND INTO LATE AFTERNOON...AND POSSIBLY
INTO THE EVENING. THERE IS CURRENTLY SOME IMPROVEMENT TO THE
NORTHWEST THAT BEARS WATCHING. STILL SEEING MIXED SIGNALS IN MODELS
AS TO WHEN CONDITIONS MIGHT IMPROVE AS SOUTHERN WISCONSIN WILL BE
UNDER THE INFLUENCE OF WARM ADVECTION AND A COUPLE SHORTWAVES
TONIGHT INTO SUNDAY. DISCOUNTING THE TYPICALLY OVERDONE NAM NEAR
SURFACE SATURATED RH LAYER...DOES SEEM THAT SOME VFR CIGS MAY RETURN
BY SUNDAY MORNING...WITH LOWER CLOUDS POSSIBLY RETURNING IN THE
AFTERNOON.
EARLIER CLEARING ALLOWED PATCHY MVFR CIGS SOUTHWEST OF MADISON THIS
EVENING. THIS AREA HAS ERODED WHILE MOVING EAST INTO DRIER AIR.
UPSTREAM AREA OF MVFR CIGS OVER NE IOWA/SW MINNESOTA ALSO APPEARING
LESS SUBSTANTIAL AS IT PROGRESSES TOWARDS US. WHILE THERE IS A LOWER
CLOUD DECK UPSTREAM AROUND 1 TO 1.5 KFT...IT/S LARGELY REMAINED SCT
TO OCCASIONALLY BKN DURING THE PAST HOUR OR SO. CURRENT THINKING IS
TO KEEP A VFR FORECAST FOR TONIGHT AND TO HANDLE ANY LOWER CIGS WITH
TEMPOS AS NEEDED. DID KEEP SOME SCT AT 1.5 KFT AT THE EASTERN TAF
SITES TO ADVERTISE THE LOWER CLOUD POTENTIAL. FLURRIES ARE POSSIBLE
OVERNIGHT IN WARM ADVECTION REGIME PRECEDING A LOW PRESSURE TROUGH.
POTENTIAL FOR LOW-LEVEL WIND SHEAR LATE TONIGHT TOWARDS MORNING AS A
35-40 KT LOW-LEVEL JET CROSSES SOUTHERN WISCONSIN. LIGHT
ACCUMULATING SNOW IS EXPECTED LATE SUNDAY EVENING INTO MONDAY.MAY
SEE A FEW SNOWFLAKES TONIGHT...BUT STILL SEEING A GOOD AMOUNT OF
DRY AIR IN MODELS SOUNDINGS. PROBABLY WILL SEE MAINLY
FLURRIES...WITH LITTLE TO NO ACCUMULATION EXPECTED. SHOULD BE DRY
THEN MID SUNDAY MORNING INTO EARLY AFTERNOON...WITH SOME LIGHT
SNOW POSSIBLE WEST LATER IN THE AFTERNOON.

MARINE...

WIND GUSTS WILL APPROACH SMALL CRAFT ADVISORY LEVELS LATE THIS
EVENING INTO SUNDAY MORNING. GUSTS LOOK BORDERLINE AT THIS TIME
THOUGH...SO WILL HOLD OFF ON AN ADVISORY FOR NOW.

&&

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

&&

$$
UPDATE PUBLIC/MARINE...MBK
UPDATE AVIATION...SPM
TONIGHT/SUNDAY AND AVIATION/MARINE...DDV
SUNDAY NIGHT THROUGH SATURDAY...HENTZ



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