Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
000
FXUS63 KMKX 120327
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
927 PM CST Wed Jan 11 2017

.UPDATE...

Have cancelled a few counties west and north of madison as the
main band of snow and freezing rain/sleet moves off and the
surface low over Lower Michigan moves northeast. This low in the
left exit region of the upper jet. A 140 knot jet max pushes into
southern Wisconsin late tonight. Upper divergence and 700 mb
upward motion increase again. Precipitation with this is across
mainly northern sections. All this happens fast due to the upper
forcing and the fast west southwest jet.

Precipitation type in the southeast mainly freezing drizzle now
due to brief drying between 5 an 10 thsd ft. This moistens with
the new round of precipitation late tonight. still not much of the
moist layer in the dendrite zone. Better moistening and dendritic
growth in the north areas. May get another inch of snow north
toward sunrise.

&&

.AVIATION/06Z TAFS/...

Freezing drizzle still possible mainly southeast.

Mainly MVFR cigs with some IFR toward Illinois border area. VFR
northwest of madison. Things should briefly quiet down, then
another shortwave arrives for the morning to spread some more
light snow across southern WI with amounts likely to remain under
an inch in the south, but around an inch toward the Dells, Fond
du lac and Sheboygan. MVFR with some IFR in the snow areas.

&&

MARINE...
Issued a Small Craft Advisory tonight, as winds have picked up
with gusts to 25 knots as the surface low moves across Lower
Michigan.

&&


.PREV DISCUSSION... /Issued 325 PM CST Wed Jan 11 2017/

SHORT TERM...
Tonight through Thursday...high confidence in the forecast
Cold front starting to very slowly push south through the
forecast area...temps had warmed into the mid 30s across much of
southern WI by early afternoon...and now those temps starting to
retreat south as front painfully slow moving to the south. As an
area of low pressure moves from Central Missouri into Illinois
through the evening the colder air will still be very slow to
drop south. Forcing from the system moving to the south will
produce widespread mixed precip...more likely snow across the
northern portions of the area...like Sauk Co across to Fond Du Lac
and Sheboygan...and freezing rain just south of there...and all
rain in the far SE areas from Milwaukee metro into Racine and
Kenosha. As the evening moves on the whole area will see frozen
precip in some form...with light freezing rain and possibly some
sleet mixed in through about midnight. Patchy light drizzle mat
linger into the early morning hours of Tuesday...but this may be
more likely across the far SE areas...and may cause a need to
extend the Winter weather advisory if this plays out. Another weak
wave moves through during the morning Thursday and exits by the
late afternoon...some light snow possible. No precip expected
Thursday evening. Temps will slowly drop across the region through
mid night as the front drops as previously mentioned...colder air
working in with lows in the teens and lower 20s across extreme SE
WI. Temps do not rebound much tomorrow with only a high about 5
degrees above the low with the cold advection behind the front.
Temps will drop into the single digits and a few spots below zero
by Friday morning.

LONG TERM...
Friday through next Wednesday...
Cold high pressure over the region Friday...slides east into New
England by Saturday. Should be mostly dry with little chances for
light snow at best on Friday night as the high moves away. Large
trough develops across the Southwestern US over the weekend should
start to push warmer air as ridging develops ahead of the deep
system. Temps start to drift higher to slightly above seasonal
levels through the weekend. Precip chances may start to increase
Sunday night as the system may start to eject out of the SW
US...it may start out as a mix late Sunday night into Monday
morning before the more likely scenario of the Warmer air surging
into the region drives most if not all of the precip to chance to
rain. Modest level of uncertainty here...most of the model
guidance leaning this way. Will need to watch the trends
here...models sometimes slower to eject these deep lows...few
items that can alter this forecast period dramatically. All models
show precip Monday morning into the early evening hours...again it
should be mostly rain...but as mentioned earlier if the cold air
doesn`t fully scour out the far northern areas may se a mix. Temps way
above normal Monday and Tuesday...may even see some lower 40s for
highs each day across portions of the area. Likely dry for
Wednesday of next week and above normal temps continue.

AVIATION/00Z TAFS/...Cold front just about south of the WI/IL
border. Pressure rise/fall couplet will keep this low to our south.
Precip slow to get going but expect things to fill in as upper jet
and 850 frontogenetical forcing increases. Few reports of various
precip types starting to come in. Still appears that at the outset
the southeast will see rain with a zone of mixed precip central and
snow northwest. Not hefty amounts by any means but expect areas warm
enough to support rain to eventually drop off to where there will be
vulnerability for freezing rain/sleet and some light snow as well.
All in all not much change in the forecast. Lowest cigs still across
Iowa but some MVFR has popped up in spots and expect more widespread
potential for IFR stratus once things saturate through a greater
depth of the column. Things should briefly quiet down later this
evening, then another shortwave arrives for Thursday morning to
spread some more light snow across southern WI with amounts
likely to remain under an inch.

MARINE...A cold front will continue to drop south into IL.
Winds have responded with a shift to the north. However gusts are
expected to remain below criteria. Waves of 2-4 feet are expected.
No Small Craft Advisory is planned at this time.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY until midnight CST tonight for WIZ051-
     052-057>060-063>066-068>072.

LM...SMALL CRAFT ADVISORY until 6 AM CST Thursday for LMZ643>646.

&&

$$

UPDATE...Hentz
TONIGHT/Thursday AND AVIATION/MARINE...Collar
Thursday NIGHT THROUGH Wednesday...BSH



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.