Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 131756 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1256 PM CDT SUN JUL 13 2014

.UPDATE...

A COLD FRONT IS DROPPING THROUGH SOUTHERN WI THIS AFTERNOON. THE
LEADING EDGE OF THE FRONTAL BOUNDARY IS LED BY WEAK 500MB
VORTICITY ADVECTION AND THE 850MB THERMAL BOUNDARY. IT IS EVIDENT
ON VISIBLE SATELLITE BY A LINE OF BROKEN CLOUDS. WINDS ARE GUSTIER
OUT OF THE WEST BEHIND THIS FIRST BOUNDARY...ALONG WITH SCATTERED
TO BROKEN CUMULUS CLOUDS. THEN A SECONDARY BOUNDARY WILL DROP
SOUTHEAST THROUGH SOUTHERN WI LATER THIS AFTERNOON...ALSO APPARENT
ON SATELLITE BY A MORE DISTINGUISHED LINE OF CLOUDS. BEHIND THE
BACK EDGE OF THIS FRONTAL BOUNDARY...THERE ARE MUCH LOWER
DEWPOINTS...FEWER CLOUDS AND A WIND SHIFT TO THE NORTHWEST.

I AM GOING TO LEAVE THE ISOLATED SHOWER MENTION IN THE FORECAST FOR
EARLY AFTERNOON UNTIL THAT SECOND BOUNDARY AND DRIER AIR GETS IN
HERE. THE DEWPOINTS ARE STILL IN THE 60S WITH DECENT CONVERGENCE.
SHALLOW CLOUD DEPTH IS THE INHIBITING FACTOR FOR GETTING MANY
SHOWERS...BUT THERE HAVE BEEN A FEW HIGHER RETURNS ON THE RADAR IN
THE SHEBOYGAN AND MANITOWOC AREAS ALREADY TODAY.

TEMPS ARE ON TRACK TO REACH AROUND 80 TODAY BEFORE THE WIND SHIFT
AND COOLER/DRIER AIR COME IN.

&&

.AVIATION/18Z TAFS/...

A BRIEF -SHRA IS POSSIBLE ALONG A COLD FRONT MOVING SOUTHEAST
THROUGH SOUTHERN WI THIS AFTERNOON. SCATTERED TO BROKEN VFR CIGS
THROUGH LATE AFTERNOON...BECOMING CLEAR THIS EVENING.

&&

.PREV DISCUSSION... /ISSUED 325 AM CDT SUN JUL 13 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM.

LINGERING LOW LEVEL MOISTURE AND INCREASING BOUNDARY LAYER WINDS
CAUSING SCT-BKN STRATUS FORMATION OVER MOST OF WI.  STRATUS EXPECTED
TO CONTINUE INTO THE EARLY MORNING BEFORE DRIER AIR ALOFT CAUSES
STRATUS TO LIFT AND THIN.  STRONGER SFC CDFNT OVER NORTHWEST WI WL
SWEEP SOUTHEAST AND MOVE ACROSS SRN WI DURING THE AFTN.  ENOUGH LOW
LEVEL MOISTURE AND FRONTOGENETICAL FORCING ALONG THIS FRONT TO SET
OFF AT LEAST ISOLD -SHRA IN THE VICINITY OF THE FRONT.  BEFORE FRONT
PASSES THROUGH...STRATUS SHOULD GIVE WAY TO PARTLY TO MOSTLY SUNNY
SKIES WHICH SHOULD HELP TEMPERATURES CLIMB BACK INTO THE UPPER 70S
TO LOWER 80S.

A QUIET NIGHT LIES AHEAD AS THE FIRST WAVE OF COOLER AIR SETTLES
INTO SRN WI.  SECOND SURGE OF COOL AIR AND DEEPER MOISTURE WILL
ACCOMPANY APPROACHING UPPER LOW ON MONDAY.

MONDAY - CONFIDENCE...MEDIUM
MORE PRONOUNCED INTRUSION OF VORTICITY AS AN UNSEASONABLY STRONG
UPPER TROUGH OF LOW PRESSURE DIGS SOUTHWARD INTO THE GREAT LAKES.
DIFFERENTIAL CYCLONIC VORTICITY ADVECTION COMBINED WITH DECENT
LAPSE RATES AND SOME CAPE SHOULD RESULT IN POTENTIAL FOR SHRA. 850
TEMPS TUMBLE TO THE 5-7C RANGE BY 00Z. THE ECMWF HAS CAUGHT UP TO
THE QUICKER GFS AND NAM WITH RESPECT TO THE PACE OF THE COLD
ADVECTION.

TUESDAY - CONFIDENCE...MEDIUM
500 MILLIBAR CLOSED LOW WILL BE WELL TO THE EAST AND NORTHEAST OF
WI. HOWEVER LINGERING CYCLONIC FLOW SUGGESTS A FEW RIPPLES TO
CONTEND WITH. ALL MODELS SHOW LIGHT QPF IN THIS REGIME ESP AFT
18Z. WILL HAVE SOME SLGT POPS IN THE WEST AND CHCY IN THE EAST.
LOW LEVEL THERMAL TROUGH MODIFIES A BIT. 925 TEMPS IN THE TEENS
CELSIUS SO WILL GO WITH MID/UPPER 60S.

WEDNESDAY THROUGH SATURDAY - CONFIDENCE...MEDIUM
UPPER FLOW STILL SHOWING A CYCLONIC CURVATURE WEDNESDAY THOUGH
SURFACE HIGH DRAWS CLOSER AND AIRMASS DRIES OUT. MAY NEED A SMALL
CHANCE OR SPRINKLES ESP IN ERN AND NE CWA AS WE GET CLOSER BUT FOR
NOW WILL GO WITH THE DRY COLLAB WITH SURROUNDING OFFICES. THEN
FAIRLY BENIGN NW FLOW TRANSITIONS TO A WEAK ZONAL REGIME FOR END
OF THE WEEK. NOT READY TO BUY INTO THE LIGHT...SPOTTY AND RANDOM
NATURE OF QPF BEING THROWN AROUND BY THE GFS. PREFER THE ECMWF
WITH OVERALL LOW LEVEL RIDGING DOMINATING INTO SATURDAY WITH THE
DRY LOOK. ANY RENEWED WAA/LLJ INDUCED PRECIP LOOKS TO HOLD OFF
UNTIL BEYOND THIS FORECAST PERIOD.

AVIATION/12Z TAFS/...SCT-BKN IFR STRATUS SHOULD THIN AND DISSIPATE
EARLY THIS MORNING AS BOUNDARY LAYER WINDS CONTINUE TO INCREASE AND
MIX DRIER AIR TO THE SFC. A BRIEF -SHRA MAY AFFECT TAF SITES LATER
THIS MRNG AND AFTN AS STRONGER CDFNT SAGS THRU SRN WI.

MARINE...WEBCAMS NOT SHOWING ANY SIGNIFICANT FOG ON THE LAKESHORE
AREAS SINCE WINDS HAVE PICKED UP FROM THE NORTHWEST. WL CANCEL MARINE
DENSE FOG ADVY WITH NEW NEAR SHORE ISSUANCE. HOWEVER PATCHY FOG COULD
CONTINUE AT LEAST THROUGH THIS MORNING OVER THE NEAR SHORE WATERS
AS DEWPOINTS WILL LINGER IN THE LOW TO MID 60S...WHICH IS LIKELY 5
TO 10 DEGREES WARMER THAN WATER. STRONGER CDFNT WL PASS ACROSS NEAR
SHORE THIS AFTN WITH DEVELOPING PRESSURE GRADIENT BEHIND FRONT
RESULTING IN NORTHWEST WINDS APPROACHING SMALL CRAFT ADVY LEVELS
MONDAY INTO TUESDAY.

&&

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

$$

UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
MONDAY THROUGH SATURDAY...COLLAR



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