Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMKX 271806
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
106 PM CDT Sat May 27 2017

.UPDATE...


&&

.AVIATION(18Z TAFS)...

MVFR CIGs should rise to VFR levels early this aftn with VFR
conditions holding until more rain and low clouds move into the
region after 6Z. There is a small chance for a SHRA/TSTM across
cntrl/e cntrl WI this aftn but this threat will diminish quickly
after sunset. Scattered precip should overspread the area after
midnight and continue in an on/off fashion most of the morning.
Overall VSBYs should remain VFR but CIGs will gradually become
MVFR from SW to NE between 6-12Z. Precip is expected to end late
mrng but a chance of rain will continue areawide thru the aftn.

&&

.PREV DISCUSSION... (Issued 931 AM CDT Sat May 27 2017)

UPDATE...

MARINE...

Visible satellite confirms the lack of fog along the
shoreline...or anywhere in the nearshore area this morning.
Should be a clear morning with mid/high clouds moving in during
the afternoon and evening Rain chances increase overnight with a
low end thunderstorm chance across the southern zones after
midnight. Southeast winds of 5-10 knots will keep waves around 1
foot. There could also be some patchy fog tonight.

PREV DISCUSSION... (Issued 736 AM CDT Sat May 27 2017)

UPDATE...

AVIATION(12Z TAFS)...

Ground fog with visibilities down to 1/4 mile at times will
quickly dissipate this morning in low lying areas, probably by
14Z or 15Z. Some areas are already fog free, per area web cameras.
Area of low ceilings and fog to the west of Madison should move
slowly east before mixing out by middle to late morning.

Should see scattered diurnal cumulus clouds develop by early
afternoon. Light winds will allow for a southeast lake breeze by
late morning near Lake Michigan, pushing inland to Burlington,
Waukesha and West Bend by late afternoon.

Ceilings will push east into the area this evening and gradually
lower to below 2000 feet later tonight. Area of showers should
push eastward across the area mainly around and after midnight. A
few thunderstorms are possible, but left out of TAFs for now due
to low confidence. Winds will remain light, with some light fog
possible later tonight with the showers.

Wood

PREV DISCUSSION... (Issued 333 AM CDT Sat May 27 2017)

UPDATE...
Updated to include aviation and marine section.

PREV DISCUSSION... (Issued 327 AM CDT Sat May 27 2017)

TODAY AND TONIGHT...Forecast Confidence Is Medium.

Areas of ground fog continue across mainly the southern and
eastern portions of the forecast area early this morning. The fog
intensity should jump around quite a bit until middle morning,
varying between light fog and patchy dense fog. Low stratus
developing may limit any patchy dense fog.

Should see some diurnal cumulus clouds develop during the late
morning into the afternoon. Lake breeze developing by the late
morning hours will keep lakeshore areas cooler than inland
locations. Highs today should be warm inland, with middle 70s
expected.

Models were showing low pressure system sliding northeast into
central or northeast Illinois later tonight. In addition, a lead
500 mb vorticity maximum will push east across the area this
evening, with a more defined 500 mb shortwave trough approaching
the area later tonight from the west. High resolution mesoscale
models were showing a line of convection pushing east across Iowa
and weakening as it clips the far southwestern counties around 00Z
Sunday.

The area will also be in the right rear quadrant of the 250 mb
jet streak as well by later tonight. This should help provide
enough upward vertical motion and combine with moisture pushing
into the region to bring good chances for showers by later
tonight.

Mesoscale models were developing an area of showers and storms in
central or northern Iowa into southeast Minnesota later this
evening with a cold front. It then pushes east northeast toward
the western counties later tonight. The frontogenesis response is
weak to modest with the front. Area forecast soundings tonight
show weak mean layer CAPE, perhaps a few hundred J/kg. Thus, kept
slight chances for thunder this evening, and just in the south
later tonight. Lows tonight should remain relatively mild, in the
middle to upper 50s.

Sunday...Forecast confidence is medium.

Precip will likely continue into the morning on the backside of
surface low pressure moving from Illinois to Michigan. Surface
winds will be northeast across the far SE part of the state on the
backside of the low and winds will be westerly upstream resulting
in a frontal boundary. A mid level trough will swing through
during the day and the frontal boundary will push through the
region as the surface low moves away. There are precip chances
with these features and a few hundred J of ML Cape contributes to
a chance for thunder as well. A closed low will drop over Lake
Superior bringing slightly cooler temperatures compared to
Saturday.

Memorial Day and Tuesday...Forecast confidence is medium

The closed mid level low will drift across Ontario and several waves
of vorticity will drop across the region. There are small chances
for showers each day. Thunder chances diminish Tuesday as surface
temperatures cool and weak warm air advection in the mid levels
reduced instability. 850 winds will increase to 25-30 knots and
steep low level lapse rates will promote mixing and breezy west
winds.

Wednesday through Saturday...Forecast confidence is medium.

The upper low will slowly move east period as ridging develops over
the plains. Surface high pressure moves across the region Wed and
Thurs bringing dry weather. The ridge breaks down
somewhat as it moves east, but temperatures will still rebound
somewhat, with highs around 70. Models differ later in this period
and show precip again at various times.

AVIATION(06Z TAFS)...

Expect ground fog to gradually expand across srn WI during the
early morning hours on Sat. Vsbys will be very variable and range
from anywhere from light fog to dense fog. The fog should remain
shallow and dissipate within 2-4 hours after sunrise. VFR
conditions the remainder of the day but good chances of showers
and thunderstorms are forecast late Sat nt. Cigs will eventually
fall to 1-3 kft early Sun AM.

MARINE...

Area web cameras and observations were indicating a lack of dense
fog over the nearshore waters of Lake Michigan early this morning.
In fact, it has been tough to see any fog. Thus, after
coordination with neighboring offices will cancel the marine Dense
Fog Advisory. Continued to mention areas of fog into the morning,
until sunrise can show if there is any extent to any remaining
fog.

&&

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

$$

Update...99
Today/Tonight and Aviation/Marine...99
Sunday THROUGH Friday...99



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