Hail in Wisconsin, March 19, 2017

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
922 PM CDT Sun Mar 19 2017

.UPDATE...850-700 mb warm, moist advection and better PVA over the
nrn half of the state has resulted in tstorms over east central
WI. A few showers will affect Sheboygan, Fond du Lac, and
possibly counties to the west over the next 2-3 hours. Otherwise
will maintain low chances for showers and tstorms for srn WI
tonight into Mon via warm, moist advection aloft followed by the
passage of a cold front. A veering LLJ should still focus the
development of more widespread showers and tstorms late tonight
over far ern IA and nrn IL.

&&

.MARINE...Light to modest wind flow with low wave heights through
Tue AM. Brisk nely winds may then develop late Tue afternoon into
Wed AM in the wake of a cold front. High wave heights may occur.

&&

.PREV DISCUSSION... (Issued 635 PM CDT Sun Mar 19 2017)

UPDATE...

AVIATION(00Z TAFS)...Elevated moisture advection currently over
wrn WI and ern IL will shift ewd with Cigs of 3.5-5.0 kft
developing this evening. Elevated CAPE is present above this level
but with only small chances of showers and tstorms with most of
the rain to develop across IA and IL late tonight. A slow moving
cold front will then move across srn WI for Mon AM. Weak flow
within a somewhat moist frontal zone may cause Vsbys to drop to
3-5SM while Cigs of 2-4 kft are forecast mainly along or south of
a line from Madison to Milwaukee. Though, cannot completely rule
out some stratus development to the north as well. Rain chances
will continue near the IL border through Mon AM with the passage
of the cold front. Nly winds will slowly bring drier air to the
area for Mon afternoon with VFR conditions eventually taking hold.
LLWS may be possible this evening into the early overnight via a
swly 35-40 kt LLJ.

PREV DISCUSSION... (Issued 238 PM CDT Sun Mar 19 2017)

SHORT TERM...

TONIGHT - Confidence...Medium Surface ridge axis will continue to
shift further away from the area. Upstream surface trough with a
flattening of the mid level ridge noted. Mid level ridging
dominates here for much of the night though the sfc/850 trough
axis will swing through later tonight. Meso models have trended
south with much of the precip though still some chances, but have
trended current pops a bit towards some of this newer data. Bufkit
soundings show quite a bit of elevated instability above 5k feet
with impressive mid level lapse rates. A mild night with a
sustained southerly wind ahead of the trough.

MONDAY - Confidence...Medium Looks like there may be a little
better phasing of the arrival of mid level vort max with the lower
level forcing across SE WI. So have somewhat higher POPS in the
SE Monday morning. With front passing to our southeast the LLVL RH
gradually decreases from NW to SE. NNE winds kick in with CAA
regime settling in.

LONG TERM...

Monday Night through Wednesday...Forecast Confidence is High:

High pressure will return for Mon night through Wed, bringing
mostly clear to partly cloudy skies. Could see little rain clip
the far sw Tue morning, but otherwise should be dry for this
period. Temps will be cooler Tue behind the departed cold front,
though still a couple degrees above normal. Below normal temps are
likely on Wednesday.

Thursday through Sunday...Forecast Confidence is Medium to High:

Models are in good agreement showing low pressure moving through
the region late in the week. This will likely bring a long period
of precip chances back into the area Thursday into Saturday.
Higher confidence in all rain for this system, as the ECMWF is
farther north again. Could see a little thunder Friday.

Near normal temps Thursday should warm back above normal Friday,
cooling again for the weekend as the low heads east and colder
air moves into the state.

AVIATION(18Z TAFS)...MVFR CU BKN-OVC field near the lake and
FEW-SCT inland will persist this afternoon. Surface high shifts
further east of WI and sets up SSE wind regime. Precip chances
tonight tied to surface cold front. Best surface based instability
is proggd to our south however BUFKIT soundings show impressive
mid level lapse rates and elevated CAPE values over 1000 j/kg, so
will retain the mention of thunder overnight. Meso models showing
various solutions with convection with latest HRRR blowing things
up just south of the WI/IL border and little or no precip in the
CWA. Potential for some post frontal lower cigs/vsbys (MVFR and
IFR) Monday morning. LLVL RH progs then show gradual drying from
nw/se as the day wears on.

MARINE...South/southeast winds ahead of a surface trough will
continue into the overnight hours. Expecting winds/waves to remain
below small craft levels though highest likely in the northern cuts
experiencing the longest fetch. On Monday winds shift to the NNE
with a favorable fetch however at this time winds and waves do not.
look like they will reach small craft criteria.

&&

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

Update...Gehring
Tonight/Monday and Aviation/Marine...Gehring
Monday Night through Sunday...DDV

Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
319 PM CDT Sun Mar 19 2017

WIZ046-047-051-052-056>060-062>072-202030-
Marquette-Green Lake-Fond Du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
319 PM CDT Sun Mar 19 2017

This Hazardous Weather Outlook is for portions of east central
Wisconsin, south central Wisconsin, and southeast Wisconsin.

.DAY ONE...Tonight

There is a chance of thunderstorms this evening and overnight
ahead of an approaching cold front.

.DAYS TWO THROUGH SEVEN...Monday through Sunday

There is a slight chance of thunderstorms Friday ahead of an
approaching low pressure system.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

LMZ643>646-202030-
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
North Point Light to Wind Point WI-
Wind Point WI to Winthrop Harbor IL-
319 PM CDT Sun Mar 19 2017

This Hazardous Weather Outlook is for portions of Lake Michigan.

.DAY ONE...Tonight

Southerly wind gusts will approach Small Craft Advisory levels
tonight, but should remain just under criteria.

There is a chance of thunderstorms this evening and overnight
ahead of an approaching cold front.

.DAYS TWO THROUGH SEVEN...Monday through Sunday

There is a slight chance of thunderstorms Friday ahead of an
approaching low pressure system.

A Small Craft Advisory may be needed Tuesday night in to Wednesday
morning as gusty north to northeast winds build higher waves.

Gusty winds and resultant waves will approach or reach Small
Craft Advisory levels Thursday and Friday ahead of approaching low
pressure and again Saturday and Sunday behind the low.

DDV

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