Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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040
FXUS63 KMKX 270259 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
959 PM CDT TUE APR 26 2016

.UPDATE...

BIG QUESTION IS AMOUNT OF CLEARING OF LOW CLOUDS OVER THE
FORECAST AREA. DRY AIR TRYING TO DROP DOWN OVER CWA BUT NOT MUCH
PUSH WITH WEAK 1 MB 3-HOURLY PRESSURE RISES UP AGAINST STALLED
BAROCLINIC ZONE TO THE SOUTH AND SOUTHWEST AS LOW DEEPENS OVER
CENTRAL KANSAS. SATELLITE IMAGERY SHOWS BACK EDGE ROUGHLY ALONG A
MINERAL POINT...MADISON TO JUST NORTH OF PORT WASHINGTON LINE.

LATEST NAM LOW-LEVEL RH FORECASTS IN AGREEMENT WITH SOME OF THE
HI-RESOLUTION MODELS TAKING THE DRY AIR OVER LOWER MICHIGAN AND
PUNCHING IT ACROSS THE LAKE IN STRENGTHENING EAST FLOW REACHING
MILWAUKEE/RACINE AROUND 09Z...MADISON AROUND 12Z AND CLEARING TO
THE WEST OF SAUK AND IOWA COUNTIES BY 15Z. HOWEVER MID-HIGH LEVEL
CLOUDS FROM CONVECTION TO THE SOUTHWEST WILL SPREAD OVER THE CWA
OVERNIGHT SO OVERALL SKY CONDITION WILL BE CLOUDY/MOSTLY CLOUDY.

&&

.AVIATION/06Z TAFS/...

LOCATIONS ALONG AND NORTH OF A PORT WASHINGTON...PORTAGE TO DELLS
LINE SHOULD BE VFR OVERNIGHT. EXPECT CLEARING OF MVFR DECK AT
KMSN TO BE RELATIVELY BRIEF WITH LOW CLOUDS JUST TO THE EAST
EXPECTED TO SPREAD BACK IN BY 04Z. LOOK TO CLEAR MVFR CLOUDS
TOWARDS THE EARLY MORNING WITH LATEST NAM LOW-LEVEL RH FORECASTS
IN AGREEMENT WITH SOME OF THE HI-RESOLUTION MODELS TAKING THE DRY
AIR OVER LOWER MICHIGAN AND PUNCHING IT ACROSS THE LAKE IN
STRENGTHENING EAST FLOW REACHING MILWAUKEE/RACINE AROUND
09Z...MADISON AROUND 12Z AND CLEARING TO THE WEST OF SAUK AND IOWA
COUNTIES BY 15Z. LOCATIONS ALONG THE ILLINOIS/WISCONSIN BORDER
LOOK TO STAY IN MVFR CLOUDS THROUGH THE DAY.

THEN LOOK FOR MVFR CLOUDS/VSBYS WITH RAIN TO MOVE BACK ACROSS THE
FORECAST AREA FROM SOUTHWEST TO NORTHEAST FROM LATE MORNING
THROUGH THE AFTERNOON AS THE LOW APPROACHES. MVFR CONDITIONS WILL
CONTINUE TO THE END OF THE FORECAST.

&&

.MARINE...
WINDS HAVE FALLEN BELOW CRITERIA BUT WAVES WILL BE SLOW TO LOWER
IN THE SOUTHERN ZONES SO WILL KEEP CURRENT END TIMES AND LET THE
NORTHERN ZONES EXPIRE AT 03Z AND KEEP THE SOUTHERN ZONES IN AN
ADVISORY UNTIL 06Z. ANOTHER SMALL CRAFT ADVISORY LOOKS NECESSARY
FOR WEDNESDAY AS WINDS INCREASE WITH THE APPROACH OF LOW PRESSURE.
THE ADVISORY MAY HAVE TO RUN ALL THE WAY THROUGH THURSDAY IN
SPITE OF A BRIEF LOWERING OF WINDS SPEEDS WEDNESDAY NIGHT.

&&

.PREV DISCUSSION... /ISSUED 329 PM CDT TUE APR 26 2016/

TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.

AREA OF LOW CLOUDS WILL LINGER INTO THIS EVENING...BEFORE MIXING OUT
BY LATER THIS EVENING. THESE CLOUDS MAY MIX OUT A BIT SOONER THAN
FORECAST...WITH A PERIOD OF SCATTERED CLOUDS POSSIBLE FOR A TIME
LATER THIS EVENING AND OVERNIGHT IN THE NORTHEAST HALF OF THE AREA.

TIGHT PRESSURE GRADIENT WILL KEEP BRISK NORTHEAST WINDS GOING ACROSS
THE AREA INTO EARLY THIS EVENING...SLOWLY WEAKENING AND VEERING TO
THE EAST LATER TONIGHT. THESE WINDS WILL BECOME GUSTY AGAIN
WEDNESDAY...AS THE PRESSURE GRADIENT TIGHTENS ONCE AGAIN.

MIDDLE TO HIGH CLOUDS WILL GRADUALLY PUSH NORTHEAST INTO THE AREA
LATER TONIGHT INTO WEDNESDAY...AHEAD OF NEXT SYSTEM IN THE CENTRAL
PLAINS. AREA FORECAST SOUNDINGS ARE SOMEWHAT SLOW TO SATURATE UNTIL
LATER WEDNESDAY AFTERNOON SOUTHWEST OF MADISON...WITH THE GUSTY
NORTHEAST TO EAST WINDS KEEPING THE LOW LEVELS SOMEWHAT DRY. SOME
FRONTOGENESIS RESPONSE PUSHES INTO THE SOUTHWESTERN PORTIONS OF THE
AREA DURING THE AFTERNOON...SO BROUGHT HIGHER POPS FOR LIGHT
RAIN INTO THAT AREA.

THE GUSTY WINDS AND CLOUDS WILL MAKE FOR A RATHER RAW AND COLD
PERIOD TONIGHT INTO WEDNESDAY. LOWS TONIGHT SHOULD BE IN THE UPPER
30S TO AROUND 40. HIGHS WEDNESDAY WILL ONLY BE IN THE 40S
LAKESIDE...AND IN THE LOWER 50S WELL INLAND.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE IS
MEDIUM.

SURFACE LOW PRESSURE WILL PASS SOUTH OF WISCONSIN THROUGH THIS
PERIOD. THE BEST ISENTROPIC SATURATION AND MOISTURE TRANSPORT WILL
BE WELL NORTH OF THE SFC LOW OVER SOUTHERN WISCONSIN. NEARLY ALL
OF THE LAYERED FRONTOGENESIS IS ACROSS OUR AREA AS WELL. THE
LIMITING FACTOR TO THE RAIN WILL BE THE DRY LOW LEVEL EASTERLY
FLOW. THE MODEL SOUNDINGS SHOW THE DRY AIR CARVING INTO THE MOIST
COLUMN ACROSS THE EAST...ESPECIALLY UP NEAR SHEBOYGAN. THE RAIN
SHOULD EASILY SPREAD ACROSS THE SOUTHWEST FORECAST AREA WEDNESDAY
NIGHT...STRUGGLING TO GET TO SHEBOYGAN BEFORE SUNRISE ON THURSDAY.
MID LEVEL SUPPORT BEGINS TO BREAK DOWN ON THURSDAY...BUT WE SHOULD
SEE ENOUGH MOISTURE AND SUCH TO KEEP THE CHANCE OF RAIN GOING
THROUGH THE DAY. LOOK FOR THE RAIN TO DIMINISH OR END THURSDAY
NIGHT. THE COOL/COLD EASTERLY FLOW WILL KEEP TEMPS AT OR BELOW
NORMAL...ESPECIALLY NEAR LAKE MICHIGAN.

FRIDAY...FORECAST CONFIDENCE IS MEDIUM.

HIGH PRESSURE STILL LOOKS LIKE IT WILL KEEP THIS DAY DRY. WE MAY
GET LUCKY AND SEE A LITTLE SUNSHINE...BUT THERE IS UNCERTAINTY
WITH THAT. TEMPS COULD HIT 60 NEAR AND WEST OF MADISON. STILL IN
THE 40S BY THE LAKE.

SATURDAY AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM.

A SFC AND MID LEVEL CIRCULATION PASS THROUGH THE AREA...TAKING A
VERY SIMILAR TRACK TO THE ONE LATE WEDNESDAY THROUGH THURSDAY.
A CHANGE FROM THE PREVIOUS MODEL RUN IS THAT IT LOOKS LIKE IT MAY
BE GOING A TAD FARTHER SOUTH. THE SAME CONCERN WILL BE THE DRY
EASTERLY FLOW AND THE IMPACT IT WILL HAVE ON THE PRECIP
PROGRESSION INTO OUR NORTH AND NORTHEAST FORECAST AREA.

MONDAY AND TUESDAY...FORECAST CONFIDENCE IS MEDIUM.

THIS LOOKS LIKE A MOSTLY DRY PERIOD WITH RIDGING TAKING HOLD.
HOWEVER...THE FLOW STILL LOOKS COOL FROM THE EAST...SO NO REAL
MILD TEMPS IN THE NEAR FUTURE.

AVIATION/00Z TAFS/...

LOW STRATUS CLOUDS WILL CONTINUE TO HAVE INCREASING CEILINGS INTO
THIS EVENING...RISING ABOVE 2000 FEET ABOVE GROUND LEVEL AND GOING
INTO VFR CATEGORY ABOVE 3000 FEET ABOVE GROUND LEVEL.

THESE LOW CLOUDS SHOULD MIX OUT BY MIDDLE EVENING AT TAF SITES.
THERE MAY BE A PERIOD OF SCATTERED CLOUDS INTO THE OVERNIGHT
HOURS...BEFORE INCREASING MIDDLE TO HIGH CLOUDS PUSH INTO THE AREA
FROM THE SOUTHWEST LATER TONIGHT INTO WEDNESDAY.

GUSTY NORTHEAST WINDS ARE EXPECTED AT THE EASTERN SITES INTO EARLY
THIS EVENING...A BIT LOWER AT MADISON. THE WINDS WILL GRADUALLY VEER
EASTWARD TONIGHT AND WEAKEN A BIT...WITH EAST TO NORTHEAST WINDS
BECOMING GUSTY AGAIN ON WEDNESDAY.

LIGHT RAIN WITH VFR CEILINGS AND VISIBILITIES MAY MOVE INTO MADISON
AFTER 21Z WEDNESDAY...AND INTO THE EASTERN SITES AFTER 00Z THURSDAY.
MAY SEE MVFR CEILINGS AND VISIBILITIES WEDNESDAY NIGHT INTO
EARLY THURSDAY WITH LIGHT RAIN.

MARINE...

SMALL CRAFT ADVISORY CONTINUES ACROSS THE NEARSHORE WATERS INTO THIS
EVENING. GUSTY NORTH TO NORTHEAST WINDS ARE EXPECTED TO CONTINUE
INTO EARLY EVENING...BEFORE GRADUALLY WEAKENING BY LATER THIS
EVENING. A TIGHT PRESSURE GRADIENT IS CAUSING THE GUSTY WINDS.

HIGH WAVES OF 4 TO 6 FEET ARE EXPECTED INTO EARLY EVENING TOWARD
SHEBOYGAN...SLOWLY SUBSIDING BY LATER THIS EVENING. WAVES MAY DROP
BELOW 4 FEET AT ALL MARINE LOCATIONS BY 10 PM CDT THIS EVENING...SO
THE SMALL CRAFT ADVISORY SOUTH OF NORTH POINT LIGHTHOUSE MAY NEED TO
BE CANCELLED BY THAT TIME.

GUSTY ONSHORE WINDS AND INCREASING WAVES ARE EXPECTED AGAIN
WEDNESDAY...WITH A TIGHT PRESSURE GRADIENT AS LOW PRESSURE
APPROACHES THE REGION. THE LOW WILL THEN PASS TO THE SOUTH OF THE
AREA WEDNESDAY NIGHT AND THURSDAY...WITH GUSTY ONSHORE WINDS AND
INCREASING WAVES POSSIBLE.

GUSTS TO 25 KNOTS ARE LIKELY BY WEDNESDAY AFTERNOON...WITH WAVES OF
3 TO 5 FEET. ANOTHER SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR
WEDNESDAY...AND MAY BE NEEDED FOR WEDNESDAY NIGHT AND THURSDAY.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR LMZ645-646.

     SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643-644.

&&

$$

UPDATE...REM
TONIGHT/WEDNESDAY AND AVIATION/MARINE...WOOD
WEDNESDAY NIGHT THROUGH TUESDAY...DDV



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