Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 260848 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
348 AM CDT THU MAR 26 2015

.TODAY...FORECAST CONFIDENCE IS MEDIUM.

BACK EDGE OF LOW CLOUD DECK HAS PUSHED INTO SW PORTIONS OF
FORECAST AREA...WITH MORE LOW CLOUDS UPSTREAM OVER NRN WI WITH
WEAK SHORT WAVE EMBEDDED IN CYCLONIC FLOW WITH DEEPENING 50 MB
TROUGH.

BIG QUESTION IS WHETHER THIS UPSTREAM CLOUD DECK WILL SETTLE OVER
SRN WI TODAY WITH COLD ADVECTION ON GUSTY NW WINDS BEHIND A
SECONDARY TROUGH...AND HOW SOON. MOS GUIDANCE AND SREF PROBABILITY
FORECASTS INDICATE LOWER DECK DROPPING INTO AREA MID-LATE MORNING.
WILL GO PESSIMISTIC WITH CLOUD COVER WHICH WILL HOLD TEMPS IN THE
UPPER 30S MOST LOCATIONS...EXCEPT FOR A FEW 40 DEGREE READINGS IN
THE SW CWA WITH A BIT OF MORNING SUN.

.TONIGHT...FORECAST CONFIDENCE IS MEDIUM.

COLD ADVECTION CONTINUES WITH 925 MB COLD POOL BRINGING LOWS IN
THE TEENS TONIGHT. DELTA T/S AND EQUILIBRIUM LEVELS OF 6K TO 7K
FEET BRING A POTENTIAL OF LAKE EFFECT SNOW SHOWERS/FLURRIES...WITH
NORTH FETCH LIMITS POTENTIAL OVER LAND TO LOCATIONS RIGHT NEAR THE
SHORE. WILL KEEP POPS IN THE SLIGHT CHANCE CATEGORY.

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

MODELS ARE IN GOOD AGREEMENT WITH HIGH PRESSURE SLIDING SLOWLY
SOUTHEASTWARD ACROSS THE NORTHERN GREAT LAKES REGION FRIDAY INTO
SATURDAY. THE HIGH WILL BRING QUIET WEATHER TO THE AREA. ONSHORE
LOW LEVEL WINDS FRIDAY NIGHT INTO EARLY SATURDAY WITH FAVORABLE
DELTA T VALUES ARE EXPECTED NEAR LAKE MICHIGAN. HOWEVER...DRY
AIRMASS IN PLACE SUGGESTS THAT ONLY A FEW CLOUDS A WORST SHOULD
OCCUR. TEMPERATURES WILL REMAIN BELOW SEASONAL NORMALS DURING THIS
PERIOD.

STRONG WARM AIR ADVECTION THEN OCCURS SATURDAY NIGHT ACROSS THE
REGION...AHEAD OF APPROACHING COLD FRONT. AREA FORECAST SOUNDINGS
SHOW MIDDLE TO HIGH CLOUDS INCREASING...WITH THE DEEPEST MOISTURE
IN THE FAR WESTERN COUNTIES. GFS ONLY MODEL TO BRING IN LIGHT QPF
BEFORE 12Z SUNDAY IN THIS AREA. WILL KEEP LOW END POPS IN THIS
AREA FOR NOW...THOUGH MAY BE ABLE TO HOLD OFF IN LATER FORECASTS.
BREEZY SOUTH WINDS DEVELOP AS WELL SATURDAY NIGHT.

.LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.

GFS/ECMWF SHOWING SOMEWHAT SIMILAR TRENDS WITH COLD FRONT/500 MB
SHORTWAVE TROUGH PASSAGE SUNDAY. GFS IS ABOUT 6 HOURS QUICKER
THAN THE ECMWF WITH THE PASSAGE OF THESE FEATURES...AND THE ECMWF
KEEPS SOME QPF IN THE FAR EAST SUNDAY EVENING. BOTH DO SHOW A
FAIRLY STRONG SHORTWAVE TROUGH. GFS KEEPS BEST QPF AND UPWARD
VERTICAL MOTION NORTH OF THE AREA...WITH THE ECMWF BRINGING A
SOLID AREA OF UPWARD VERTICAL MOTION AND QPF THROUGH THE AREA.

FOR NOW...WILL CONTINUE WITH THE CHANCE POPS FOR SUNDAY...AND IN
THE FAR EAST SUNDAY EVENING. MAY SEE A RAIN/SNOW MIX EARLY SUNDAY
MORNING BEFORE MILDER TEMPERATURES OCCUR.

MODELS THEN DIFFER WITH THE MONDAY NIGHT PERIOD. THE ECMWF BRINGS
A LOW WITH A STRONG 500 MB VORTICITY MAXIMUM THROUGH THE AREA WITH
SOME QPF. THE GFS IS DRY DURING THIS TIME. KEPT LOW END POPS FOR
LATER MONDAY INTO MONDAY NIGHT FOR NOW.

THEY ARE IN BETTER AGREEMENT WITH WARM AIR ADVECTION TUESDAY INTO
WEDNESDAY...AHEAD OF ANOTHER APPROACHING COLD FRONT. THE FRONT AND
ASSOCIATED QPF MOVES INTO THE AREA WEDNESDAY. KEPT CONSENSUS MODEL
POPS FOR THIS PERIOD. MILDER TEMPERATURES SHOULD OCCUR AS WELL.

.AVIATION/12Z TAFS/...WITH SOME CLEARING OF STRATUS DECK INTO SW
PORTIONS OF FORECAST...THE BIG QUESTION IS WHETHER UPSTREAM
VFR/MVFR CLOUD DECK WILL SETTLE OVER SRN WI TODAY WITH COLD
ADVECTION ON GUSTY NW WINDS WITH A SECONDARY TROUGH...AND HOW
SOON. MOS GUIDANCE AND SREF PROBABILITY FORECASTS INDICATE LOWER
DECK DROPPING INTO AREA MID-LATE MORNING. WILL ADJUST FOR INITIAL
CLEARING AT ISSUANCE TIME...BUT OVERALL WILL GO PESSIMISTIC WITH
CLOUD COVER BUT KEEP IT AT VFR LEVELS.

NORTHWEST WINDS WILL SHIFT TO THE NORTH THIS EVENING BEHIND COLD
FRONT/SURFACE TROUGH. CONDITIONS FAVORABLE FOR DEVELOPMENT OF
LAKE-EFFECT SNOW SHOWERS...THOUGH MOST GUIDANCE KEEPING IT OUT
OVER THE LAKE. A SLIGHT CHANCE FOR KMKE...AND POSSIBLY KENW TO BE
BRUSHED BY SCATTERED LIGHT SNOW SHOWERS OR FLURRIES BETWEEN 03Z
AND 09Z BUT TOO LOW A PROBABILITY TO ADD TO TAFS AT THIS TIME.

.MARINE...NORTHWEST WINDS WILL INCREASE THIS MORNING...WITH GUSTS
TO 20 KNOTS...BUT WITH OFFSHORE FETCH LIMITING WAVE HEIGHTS
CONDITIONS WILL REMAIN BELOW SMALL CRAFT LEVELS. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED TONIGHT THROUGH FRIDAY AS WINDS
SHIFT TO THE NORTH WITH GUSTS NEARING CRITERIA TONIGHT WITH
PASSAGE OF COLD FRONT/SURFACE TROUGH. NORTH FETCH WILL BUILD WAVES
TO 4 TO 6 FEET OVERNIGHT THROUGH FRIDAY...THEN SUBSIDE FRIDAY
NIGHT WITH EASING WINDS LATE FRIDAY AFTERNOON AND EVENING.

&&

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

$$

TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...WOOD


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