Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 151914
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
215 PM CDT TUE OCT 15 2019

.SHORT TERM...

TONIGHT AND WEDNESDAY - Forecast Confidence...High.

Kept slight chances for showers and storms in the forecast this
afternoon for possible development along the cold front. Only
elevated instability will be present and dynamics are better to the
north. Stratus will continue to develop along and behind the cold
front this afternoon. Breezy sswly winds will become wly late this
afternoon and early evening. The passage of the upper trough late
this evening into the early morning hours will result in sct showers
mainly north and east of Madison. Breezy nwly winds will continue
late tnt into Wed as the sfc low deepens from nrn Lake MI to Lake
Huron. Some breaks in the cloud cover should occur for Wed afternoon
but a cool day is expected.

WEDNESDAY NIGHT THROUGH FRIDAY - Forecast Confidence...Medium to
High.

A quiet and cool period is expected with short wave ridging moving
through the western Great Lakes.  Cold air stratocumulus initially
over the area is expected to thin and breakup overnight but may hang
on in some eastern areas closer to thermal trof.  A period of mid-
high clouds is also possible due to a brief surge of upstream warm
air advection. Never the less, with diminishing winds and 925H temps
falling to around 1-3C, will include a frost mention for the
overnight hours. A slight modification in temperatures is expected
on Thursday, but will remain below seasonal normal for mid-October.
Increasing south winds ahead of a low pressure system will result in
warmer temperatures, but breezy conditions on Friday.

.LONG TERM...

FRIDAY NIGHT THROUGH TUESDAY - Forecast Confidence...Medium.

Protective short wave ridging over the western Great Lakes will move
off to the east Friday night, succumbing to amplifying upstream
short wave trof over the central and northern Plains.  Medium range
guidance in good agreement in keeping this trof progressive and
steadily moving east through the western Great Lakes due to farther
upstream short wave moving toward the Pacific northwest. Low level
jet quickly ushers deeper moisture back into Wisconsin Friday night
and Saturday morning as precipitable water surges to around 1",
however jet looks to be weakening as it moves through southern WI
during the morning. Will continue chance of showers with a small
chance for a t-storm as weakly elevated CAPE is expected along weak
front.

Zonal steering flow will transition to south to southwest ahead of
next digging short wave trof in the central and northern Plains late
in the weekend.  The guidance remains in good agreement on this
deepening short wave and low pressure system moving northeast
through the northern Plains and upper midwest early next week.  A
period of showers and thunderstorms will be possible as the
associated cold front moves through around the Monday time frame.
There are differences in how fast the cold front moves through
Wisconsin, however good news is that the trend is toward this system
remaining progressive as well. Colder air will then return Monday
night and Tuesday.

&&

.AVIATION(21Z TAF UPDATE)...The cold front and stratus development
will continue from west to east across srn WI this afternoon. Cigs
of 2500-4000 feet are expected. This stratus will continue into the
evening and eventually lower to 1-3 KFT for the night and Wed AM.
Cigs will rise to 3.5-4.0 kft during Wed afternoon. Modest sly winds
will shift wly during the afternoon and become breezy. Breezy west
to nwly winds are then expected tnt-Wed.

&&

.MARINE...Low pressure around 29.7 inches over central WI will
deepen to 29.5 inches as it moves to Lake Huron tonight. Breezy
ssely winds this afternoon will shift wly early this evening with
the passage of a strong cold front. Winds over far nrn Lake MI will
become variable this evening as the low pressure area passes over
that area. Nwly gales will then develop over all of the lake during
the early morning hours of Wed and last through the day. The nnwly
winds will gradually weaken through Wed nt. Much lighter winds are
then expected for Thu-Fri as high pressure moves across the lake. A
Small Craft Advisory remains in effect from Sheboygan to Winthrop
Harbor until 08Z Wed, which will be followed by a Gale Warning until
19Z. A Gale Warning is in effect for the open lake from 08Z Wed
until 00Z Thu.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...

WI...None.
LM...Gale Warning from 3 AM to 7 PM CDT Wednesday for LMZ080-261-362-
     364-366-563-565-567-669-671-673-675-777-779-868-870-872-874-
     876-878.

     Small Craft Advisory until 3 AM CDT Wednesday for LMZ643>646.

     Gale Warning from 3 AM to 2 PM CDT Wednesday for LMZ643>646.

$$

TONIGHT AND WEDNESDAY/AVIATION/MARINE...MG
WEDNESDAY NIGHT THROUGH TUESDAY...MBK


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