Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 270235
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
935 PM CDT SUN OCT 26 2014

.UPDATE...THE LOW LEVEL JET OVER IA AND MN WILL VEER INTO SRN WI
LATER TNT WITH WARM...MOIST ADVECTION AND FRONTOGENESIS
INCREASING. MESO MODELS AND SYNOPTIC MODELS FOCUS THE SHOWER AND
TSTORM DEVELOPMENT OVER THE ERN AND NRN CWA AFTER 06Z. SHOWERS
AND TSTORMS TO MOVE EAST OF THE AREA BY SUNRISE. THE WARM SECTOR
WILL THEN MAKE IT INTO SE WI BY AFT WITH SOME SUNSHINE POSSIBLE
AND TEMPS INTO THE LOW 70S. LOW PRESSURE WILL THEN MOVE NEWD
ACROSS SRN WI MON EVE WITH A COLD FRONT TO FOLLOW. FRONTOGENESIS
AND THE APPROACHING UPPER TROUGH WILL LIKELY RESULT IN SHOWER
REDEVELOPMENT ESPECIALLY OVER ERN WI.

&&

.AVIATION/06Z TAFS/...WARM...MOIST ADVECTION WILL TRIGGER
SCATTERED TO NUMEROUS SHOWERS AND TSTORMS DURING THE EARLY MORNING
HOURS OF MON OVER SRN WI. THE SAID ADVECTION WILL EVENTUALLY LEAD
TO BROKEN STRATUS 1-3 KFT DURING THE EARLY MORNING HOURS. THE WARM
FRONT WILL MOVE INTO SE WI BY THE MIDDLE OF THE DAY WITH THE
STRATUS LIFTING TO SCT-BKN CLOUDS AT 3.5-5.0 KFT ALTHOUGH LOW
STRATUS WILL REMAIN OVER SOUTH CENTRAL WI. THE PASSAGE OF LOW
PRESSURE AND ITS COLD FRONT WILL THEN BRING MORE SHOWERS TO SRN WI
MON NT. LOW STRATUS AND VSBYS OF 2-4SM ARE EXPECTED.

&&

.MARINE...BREEZY SLY WINDS WILL GENERATE HIGH WAVES LATE TNT INTO
MON AFT. THE PRESSURE GRADIENT WILL THEN WEAKEN BY MID TO LATE
MON AFT.


&&

.PREV DISCUSSION... /ISSUED 340 PM CDT SUN OCT 26 2014/

TONIGHT - CONFIDENCE...MEDIUM
STARTING TO SEE THE EARLY SIGNS OF WARM AIR ADVECTION WITH NW/SE
ORIENTED BAND OF MID CLOUDS ACROSS SRN MN INTO NE IA. PER 700 MILLIBAR
RH PROGS THIS WILL LIKELY EXPAND ACROSS WRN WI INTO THIS EVENING AS
850 LLJ INCREASES INTO SRN/CNTRL WI. MODELS SHOW PRECIP MOST LIKELY IN
CNTRL/NRN WI WITH SMALLER CHCS IN SRN WI. LATE NIGHT ELEVATED CAPE
ROOTED BETWEEN 800-850 MILLIBARS YIELDS ANYWHERE FROM 500-1500 J/KG...
WITH THE NAM BEING THE MORE UNSTABLE. GFS NOT NEARLY AS MUCH. SO WILL
CARRY ON THE THE MENTION OF THUNDER.

MONDAY - CONFIDENCE...MEDIUM
SURFACE LOW PROGGD TO NRN IL OR SRN WI WITH INVERTED TROUGH/WARM FRONT
EXTENDING NEWD FROM LOW CENTER. AT THIS TIME MODELS TAKE THE FRONT NORTH
OF THE CWA ALLOWING FOR A MOIST AND SOUTHERLY FLOW TO DOMINATE. LLVL RH
PROGS SUGGEST WARM SECTOR WILL BE ON THE MESSY SIDE MONDAY WITH STRATUS
POTENTIAL KEEPING INSTABILITY LOWER FOR MUCH OF MONDAY WITH 850/LLJ INDUCED
FORCING DECREASING AND FRONTAL FORCING STAYING LARGELY WEST OF CWA
UNTIL LATER IN THE DAY. WILL NOT COOL TEMPS MUCH FROM PRIOR FORECAST
BUT IF NAM MOISTURE PROFILE VERIFIES LOWERING WILL BE NEEDED BUT
LEANING TOWARDS MORE OF A COMPROMISE APPROACH FOR NOW AMONGST OTHER
MODELS.

SHORT TERM...MONDAY NIGHT THROUGH WEDNESDAY.

MONDAY NIGHT...FORECAST CONFIDENCE MEDIUM.

PCPN MAXES ON NAM...GEM AND ECMWF COME INTO SRN WI WITH STRONG LOW-
LEVEL FRONTOGENESIS ALONG SURFACE TROUGH/COLD FRONT AND OVERALL
FORCING FOR ASCENT DUE TO STRONGER UPPER LEVEL DIVERGENCE OVER SRN
WI WHILE GFS KEEPS THE STRONGER ULD AND OMEGA...AND THUS HIGHER PCPN
SOUTHEAST OF FORECAST AREA...AS DOES THE SREF. BOTH NAM AND GFS
FORECAST SOUNDINGS SHOWING A STOUT CAP BETWEEN 800 AND 700 MB THAT
LIMITS SURFACE AND ELEVATED CAPE. NAM INDICATING EVAPORATIVE COOLING
WILL WASH THE CAP OUT...WITH STEEP LAPSE RATES ABOVE 700 MB HELPING
TO PRODUCE 600-1000 J/KG OF ELEVATED CAPE WITH PARCELS ORIGINATING
AROUND 925 MB...MAINLY IN THE EASTERN CWA WITH THE HIGHEST ELEVATED
CAPE VALUES IN THE SOUTHEAST. GFS DOES NOT LOSE THE CAP AND LIMITS
POTENTIAL FOR THUNDER. SPC FAVORS THE MORE STABLE LOOK OF THE GFS
AND HAS REMOVED MARGINAL PROBABILITY FOR SEVERE HAIL FROM SRN WI IN
THE LATEST DAY 2 OUTLOOK. WILL GO WITH MAINLY SHOWERS AND CHANCE OF
THUNDER.

TUESDAY AND TUESDAY NIGHT...FORECAST CONFIDENCE HIGH

WILL LINGER CHANCES FOR SHOWERS INTO TUESDAY MORNING WITH FORCING
ASSOCIATED WITH PASSAGE OF 500 MB TROUGH ROTATING THROUGH THE
REGION...ENDING WITH SUBSIDENCE BEHIND TROUGH AXIS. COLD ADVECTION
ON BRISK WEST WINDS DROPS 850 MB TEMPS ABOUT 5C BETWEEN 12Z TUE AND
00Z WED. HIGHS REACH THE MID TO UPPER 50S AROUND MIDDAY THEN STEADY
OUT AND SLOWLY COOL THROUGH THE AFTERNOON. SHORT WAVE TROUGH CROSSES
REGION TUESDAY NIGHT...BUT LIMITED MOISTURE WITH MODEL AGREEMENT
THAT ANY PCPN WITH THIS WAVE WILL BE LIMITED TO NRN WI. WINDS HOLD
UP INTO THE OVERNIGHT PROVIDING SUFFICIENT MIXING TO HOLD LOWS IN
THE MID TO UPPER 30S.

WEDNESDAY AND WEDNESDAY NIGHT...FORECAST CONFIDENCE HIGH.

QUIET WEATHER WITH SURFACE RIDGE WEDNESDAY...WITH SHORT WAVE
APPROACHING FROM WEST WEDNESDAY NIGHT. COLDEST 925-850 MB TEMPS
SETTLE OVER STATE...WITH HIGHS STRUGGLING TO REACH 50. ONLY GFS
SHOWING ANY WARM AIR ADVECTION DRIVEN PCPN AHEAD OF THE REACHING SRN
WI BY THURSDAY MORNING. WILL GO WITH BLENDED SOLUTION THAT LEAVES
FORECAST AREA DRY.

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

LEFT BLENDED SLIGHT CHANCE POPS IN THE EAST THURSDAY...THOUGH MAY BE
OVERLY INFLUENCED BY GFS POPS WITH FIRST WAVE. SECOND STRONGER WAVE
DROPS ACROSS NORTHERN WI THURSDAY NIGHT...AND ACROSS LOWER MI
FRIDAY. 1000-500 MB THICKNESSES INDICATE POTENTIAL FOR A FEW SNOW
FLAKES MIXING IN WITH THE RAIN AFTER MIDNIGHT THURSDAY NIGHT...BUT
GFS AND ECMWF SOUNDINGS ARE DRY IN DENDRITE GROWTH ZONE SO WILL STAY
WITH CHANCE/SLIGHT CHANCE FOR RAIN.

PCPN CLEARS THE EAST FRIDAY MORNING...WITH UPPER RIDGING AND COLD
HIGH PRESSURE SETTLING OVER THE REGION BRINGING BELOW NORMAL
TEMPERATURES. PRECIPITATION CHANCES RETURN LATE SUNDAY
AFTERNOON/SUNDAY NIGHT...DEPENDING ON MODEL...WITH WARM AIR
ADVECTION ON 30-40 KT LOW-LEVEL JET. GFS MORE GENEROUS WITH PCPN
THAN ECMWF...LEADING TO A SMALL CHANCE FOR PCPN ACROSS ONLY THE
NORTHERN CWA IN BLENDED SOLUTION. WILL PROBABLY SEE POPS INCREASE ACROSS
ALL OF THE CWA IN LATER RUNS.

AVIATION/00Z TAFS/...VFR SKC INTO THIS EVENING HOWEVER LLVL WAA
WILL BE ON THE INCREASE LEADING TO MORE IN THE WAY OF MID CLOUDS
ARRIVING. ELEVATED CAPE AND FORCING FROM LLJ WILL TRY TO OVERCOME
THE INITIALLY DRY AIRMASS TO PRODUCE SHRA/ISOLD T. MODELS ARE
SKEWING HEAVIER PRECIP NORTH OF TAF SITES HOWEVER MESO MODELS
SHOWING A COUPLE DIFFERENT ROUNDS OF SHRA POSSIBLE AS THE NIGHT
WEARS ALONG. AGAIN...THUNDER CANNOT BE RULED OUT. MONDAY BECOMES
TRICKY WITH WARM FRONT TRYING TO LIFT NORTH AND MODELS SHOWING
VARYING SOLUTIONS WITH RESPECT TO HOW MOIST THE LOW LEVELS WILL BE.
FOR NOW TOOK A COMPROMISE APPROACH AND DID NOT STRICTLY FOLLOW THE
VERY MOIST NAM OUTPUT.

MARINE...PONDERED SMALL CRAFT FOR THE PRESSURE GRADIENT AHEAD OF
APPROACHING LOW PRESSURE BUT CONFIDENCE LOW RIGHT NOW ON EVOLVING
POSITION OF SURFACE TROUGH AXIS WITH TIME. SOUTHEAST WINDS WILL
INCREASE FOR A TIME BUT THEN PRESSURE PATTERN BECOMES BAGGY WITH
SURFACE TROUGH. IF ANY AREA CAN BE POSITIONED IN A TIGHTER GRADIENT
FOR A LONGER PERIOD OF TIME THEN MALL CRAFT CONDITIONS WILL PERSIST
TO WARRANT A HEADLINE. CONFIDENCE TOO LOW ON THE SCENARIO TO HOIST A
HEADLINE AT THIS TIME.

HOWEVER SMALL CRAFT ADVISORY LEVEL WINDS ARE MORE LIKELY MONDAY
NIGHT THROUGH AT LEAST TUESDAY NIGHT...AS A TIGHT PRESSURE GRADIENT
DEVELOPS AFTER A COLD FRONTAL PASSAGE. GUSTS TO 25 KNOTS ARE A GOOD
BET DURING THIS TIME. HIGH WAVES SHOULD REMAIN OVER THE OPEN
WATERS...GIVEN THE OFFSHORE NATURE OF THE WINDS.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 3 AM TO 4 PM CDT MONDAY FOR LMZ643>646.

&&

$$

UPDATE...GEHRING
TONIGHT/MONDAY AND AVIATION/MARINE...COLLAR
MONDAY NIGHT THROUGH SUNDAY...REM



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