Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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000
FXUS63 KMKX 121651
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1151 AM CDT SAT APR 12 2014

.UPDATE...850 WARM ADVECTION DRIVING STORM CLUSTERS ACRS FAR SE
WI/NE IL AND WC WI. WHILE THE KENW ACTIVITY WILL SHIFT EAST THE
ACTIVITY IN WC WI WILL LIKELY TRAVERSE THE NRN CWA. EXPECTING A
BREAK IN MUCH OF THE SRN CWA THIS AFTN. SFC WARM FRONT STRETCHES
FROM NRN IL INTO SW WI AND EXTREME NRN IA. THE LAKE IS DOING ITS
PART TO BEAT IT BACK. MODELS FOR THE MOST PART REFOCUS THINGS BACK
TOWARDS IOWA AND BRING THAT COMPLEX ACROSS OVERNIGHT. THE 4KM SPC
WRF ACTUALLY TAKES IA ACTIVITY INTO IL WITH SUBSEQUENT DISSIPATION.
CERTAINLY SOME HIGHER DEW POINT AIR WILL MAKE IT INTO PARTS OF SC
WI WHERE STORMS MAY RIDE ALONG THE WARM FRONT.

PC

&&

.AVIATION/18Z TAFS/...SURFACE WARM FRONT WILL EXTEND INTO SC WI
WITH MORE STABLE EASTERLY FLOW NEAR LAKE MICHIGAN. CLUSTER OF
STORMS IN WC WI LIKELY TO STAY NORTH OF TAF ROUTES THIS AFTERNOON.
BEST CHANCE FOR MORE STORMS WILL BE TONIGHT WHEN RENEWED ACTIVITY
DEVELOPS ACROSS IA AND ROLLS ACROSS SRN WI. AS LOW AND TROUGH MOVE
ACRS SRN WI TNGT CIGS/VSBYS EXPECTED TO LOWER TO IFR. THIS PLAYED
OUT ON MOS AND LLVL RH PROGS.

PC

&&

.MARINE...SMALL CRAFT ADVISORY PRETTY BORDERLINE AT THIS POINT.
GRADIENT TRYING TO TIGHTEN UP AND WINDS HAVE PICKED UP A SMIDGE.
WILL NOT THROW IN THE TOWEL JUST YET. WARM FRONT WILL STRUGGLE TO
ADVANCE NORTHWARD...SO WILL BANK ON PREFRONTAL ONSHORE COMPONENT
PICKING UP THIS AFTERNOON.

PC

&&

.PREV DISCUSSION... /ISSUED 330 AM CDT SAT APR 12 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.

MODELS ARE ALL IN VERY GOOD AGREEMENT THAT WE/LL SEE TWO ROUNDS OF
PRECIP DURING THIS PERIOD. THE FINER DETAILS ARE A LITTLE MORE
MUDDY. THE FIRST ROUND WILL COME THROUGH THIS MORNING WITH THE
ARRIVAL OF STRONG WARM AIR ADVECTION INTO THE UPPER
MIDWEST...ACCOMPANIED BY A WEAK MID LEVEL SHORT WAVE.  A SURFACE
WARM FRONT WILL BECOME MUCH BETTER DEFINED THIS MORNING AS THE
EASTERLY FLOW OFF LAKE MICHIGAN INCREASES AND SHARPENS THE CONTRAST
BETWEEN THE LAKE COOLED AIR TO THE NORTH AND THE WARMER AIR PUSHING
UP FROM THE SOUTH. THE FRONT MAY ONLY MAKE IT UP TO A MILWAUKEE TO
BARABOO LINE WITH THE LAKE SHORE NORTH OF MILWAUKEE REMAINING RATHER
CHILLY. PRECIP IS INCREASING ACROSS NORTHERN IOWA AND MINNESOTA AS
THE LOW LEVEL JET IMPINGES ON THAT AREA. THAT JET WILL LEAN INTO
WISCONSIN WITH TIME AND INTERACT WITH THE WARM FRONT PUSHING INTO
SOUTHERN WI. MOST OF THE MESO MODELS ARE FOCUSING THE BEST QPF FOR
THIS FIRST ROUND MAINLY ALONG AND NORTH OF A LINE FROM MILWAUKEE TO
MADISON. BUT...WHERE THIS PRECIP IS CURRENTLY BREAKING OUT IS SOUTH
OF WHERE THE MESO MODELS INITIATED...SO AT LEAST A SMALL SOUTHERN
CORRECTION IS PROBABLY NEEDED. THERE ISN/T MUCH INSTABILITY WITH
THIS MORNING PRECIP...SO MAINLY SHOWERS WITH A CHANCE FOR A RUMBLE.

I WOULD EXPECT A LULL IN THE ACTIVITY IN THE WAKE OF THE FIRST ROUND
OF PRECIP AS IT LIFTS OFF TO THE EAST NORTHEAST.  THE TRAILING
SURFACE BOUNDARY WILL LINGER ACROSS THE FORECAST AREA SO CAN/T RULE
OUT SOME SCATTERED SHOWERS OR A THUNDERSTORM IN IT/S VICINITY THIS
AFTERNOON. AS WE HEAD INTO THE LATE AFTERNOON...INSTABILITY WILL
INCREASE WITH TEMPS LIKELY CLIMBING INTO THE UPPER 60S TO LOWER 70S
ALONG AND SOUTH OF THE FRONT. DEWPOINTS SHOULD INCREASE INTO THE
LOWER 50S AS WELL. DEWPOINTS ARE ALREADY IN THE LOWER AND MID 50S
FROM CENTRAL KS INTO MO. MUCAPES WILL BE ON THE ORDER OF 1000-
1500J/KG. WITH PLENTY OF DEEP LAYER SHEAR...PUSHING 40-50KTS...THE
SLIGHT RISK FROM SPC LOOKS GOOD. WE/LL LIKELY SEE CONVECTION LIGHT
UP ALONG THE FRONT LATE THIS AFTERNOON AND EVENING...THEN POSSIBLY
ORGANIZE INTO A LARGER COMPLEX THAT PUSHES ACROSS SOUTHERN WISCONSIN
LATE THIS EVENING TO SHORTLY AFTER MIDNIGHT. WOULD THEN EXPECT
THINGS TO QUIET DOWN THROUGH SUNRISE SUNDAY...BEFORE THE NEXT ROUND
MOVES IN.

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

MODELS HAVE THE SFC BOUNDARY RIGHT ALONG THE ILLINOIS BORDER BY
SUNDAY MORNING...WITH THE FRONT EXPECTED TO THEN SLOWLY PUSH SOUTH
DURING THE DAY. WITH THE FRONT SOUTH AND WINDS NORTH TO
NORTHEAST...TEMPS ARE EXPECTED TO BE A GOOD DEAL COOLER THAN ON
SATURDAY.

MODELS ARE SHOWING QUITE A BIT OF LIFT DUE TO FRONTOGENETICAL AND
ISENTROPIC FORCING SUNDAY AND SUNDAY NIGHT...AS SURFACE LOW
PRESSURE PASSES BY TO THE SOUTHEAST. THUNDER CHANCES WILL CONTINUE
INTO THE EVENING.

TEMPS CRASH SUNDAY EVENING AND OVERNIGHT...BRINGING A LIKELY
CHANGEOVER TO SNOW FROM NORTHWEST TO SOUTHEAST. MODELS ARE IN
BETTER AGREEMENT AS TO HOW MUCH PRECIP WILL FALL AFTER TEMPS ARE
COLD ENOUGH FOR SNOW...WITH LOWER AMOUNTS OF MAINLY LESS THAN AN
INCH NOW EXPECTED. NOT SURE HOW WELL THE SNOW WILL ACCUMULATE
ANYWAY AFTER THE PERIOD OF MILDER TEMPS...BUT THERE COULD BE SOME
ON THE GROUND BY MORNING. LOOKS CHILLY THROUGH THE DAY
MONDAY...WITH HIGHS ONLY TOPPING OUT IN THE LOW 40S.

TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM

IT SHOULD BE DRY TUESDAY AS HIGH PRESSURE SLIDES THROUGH. THOUGH
TEMPS ALOFT WILL BE WARM ADVECTING THROUGH THE DAY...THE COLDEST
AIRMASS WILL BE OVERHEAD AT DAYBREAK. AFTERNOON HIGHS ARE THUS
EXPECTED TO STRUGGLE INTO THE UPPER 30S AND LOW 40S.

TEMPERATURES SHOULD BE RETURN TO NEAR NORMAL VALUES BY
THURSDAY. MODELS ARE IN BETTER AGREEMENT WITH THE OVERALL PATTERN
FOR THE LATTER HALF OF THE WEEK...BUT STILL HAVE SOME SIGNIFICANT
DIFFERENCES WITH STORM TRACKS AND RESULTANT PRECIP CHANCES. USING
A CONSENSUS OF THE MODELS...ENDED UP WITH LOW POPS FOR MUCH OF THE
WEDNESDAY THROUGH FRIDAY PERIOD...WITH RAIN THE MOST LIKELY PRECIP
TYPE.

AVIATION/12Z TAFS/...RAIN AND POSSIBLE THUNDERSTORM CHANCES WILL
INCREASE THIS MORNING AS A WARM FRONT ADVANCES NORTH INTO SOUTHERN
WISCONSIN. THAT FRONT SHOULD CROSS THE WI/IL BORDER AROUND MID
DAY...LIFTING NORTH OF MILWAUKEE AND MADISON BY MID AFTERNOON.
ALTHOUGH MUCH OF THE DAYTIME PERIOD SHOULD BE VFR...WE COULD SEE A
BRIEF MVFR CONDITIONS THIS MORNING AS THE FIRST ROUND OF RAIN MOVES
THROUGH. WE SHOULD SEE A LULL IN THE RAIN/THUNDERSTORM CHANCES EARLY
THIS AFTERNOON...BUT BECOMING LIKELY AGAIN LATE IN THE AFTERNOON.
THE SFC BOUNDARY WILL BE LINGERING ACROSS THE AREA AND WILL BEGIN TO
LIGHT UP WITH THUNDERSTORMS AS DIURNAL HEATING MAXIMIZES. THE FRONT
WILL EVENTUALLY PUSH SOUTH AND EAST THROUGH THE AREA WITH
THUNDERSTORMS DIMINISHING AGAIN LATER IN THE TAF PERIOD.  MVFR
CONDITIONS ARE EXPECTED WITH THE SECOND ROUND OF PRECIP LATE THIS
AFTERNOON AND TONIGHT. THERE IS A SLIGHT RISK FOR SEVERE
THUNDERSTORMS.


MARINE...BRISK SOUTHERLY WINDS ARE EXPECTED SOUTH OF A WARM FRONT
THAT WILL BE SLOW TO MOVE NORTH INTO THE AREA. THE LAKE COOLED AIR
NORTH OF THE WARM FRONT WILL BE INHIBITING THE MOVEMENT OF THE
FRONT. HOWEVER...AREAS SOUTH OF PORT WASHINGTON SHOULD GET INTO SOME
GUSTY SOUTHERLY WINDS OF 25KTS THROUGH ABOUT 7 PM THIS EVENING.
THUS A SMALL CRAFT ADVISORY IS IN EFFECT FROM MID MORNING THROUGH
THE AFTERNOON.

A MORE PROLONGED PERIOD OF SMALL CRAFT ADVISORY CONDITIONS IS
EXPECTED FROM SUNDAY AFTERNOON THROUGH MONDAY NIGHT AS BRISK
NORTHERLY WINDS ARRIVE IN THE WAKE OF A DEPARTING LOW PRESSURE
SYSTEM.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ644>646.

&&

$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
SUNDAY THROUGH FRIDAY...DDV



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