Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 171745
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
Issued by National Weather Service Chicago IL
1245 PM CDT TUE MAY 17 2016
High pressure building in from the north will bring some sunshine
today along with cooler temperatures. Model soundings do suggest
late morning and afternoon cumulus will develop, which is not
surprising given the colder air aloft. Temperatures will be
several degrees below normal for mid-May, with the coolest temps
near Lake Michigan under northeast winds.
VFR conditions will prevail through Wednesday under high pressure.
Late morning and afternoon cumulus will develop today and likely
again on Wednesday. North-northeast winds will be sustained near
15 kt this afternoon at near lake airports, with gusts to 20 kt at
times. Northeast winds will be lighter on Wednesday.
North to northeast flow to continue today into this evening before
land breeze develops overnight shifting winds to more north to
northwest. Few gusts likely around 20 knots today before settling
down later this aftn and eve. Wave heights to around 3 feet are
expected where the stronger winds will linger longest in the
southern zones today. Recent report from Coast Guard vessel located
at the Kenosha break wall measured 3 foot waves with north winds at
15 knots. Other vessels in Port Washington and Milwaukee harbors
reported sustained winds mostly 10 to 15 knots as well, at 13Z.
A quiet period lies ahead with high pressure remaining across the
Great Lakes through the weekend. Expect light winds becoming onshore
during the day, with low wave heights.
PREV DISCUSSION... /Issued 329 AM CDT TUE MAY 17 2016/
TODAY...Forecast Confidence High.
Cold front/surface trough is still slowly making its way through
the far southern forecast area, held up by weak surface waves
moving along the boundary, driven by weak short wave energy
spinning through the base of the mid-level trough. Any isolated
showers/sprinkles should exit the forecast area by 12z with the
front and increasing subsidence and drying behind last of the
short waves, with the axis of mid-level trough sinking south of
the forecast area by 18z.
Steep low-level lapse rates on forecast soundings indicate good
potential for shallow scattered to broken diurnal cumulus
development inland late this morning and afternoon, with few
clouds in the far east with northeast winds bringing cooler and
more stable air off of Lake Michigan. Cold pocket at 925 mb swings
across mainly the NE CWA this morning with a bit of a rebound in
the west this afternoon. Consensus blend high temperatures follow
this trend of warm western forecast area highs around 60 tapering
down towards the lake with the northeast winds.
TONIGHT...Forecast Confidence High.
Surface high pressure settles over the state tonight. Went a couple
of degrees below any of the guidance as good radiational cooling
conditions should assure everyone drops into the 30s away from Lake
Michigan tonight, with patchy frost developing after midnight.
Concern is that if the dew point temperatures fall a few degrees
more than forecast, temperatures will cool more as well and the
frost will become more widespread bringing the need for frost
advisory. Later shifts will have to assess trends with later model
WEDNESDAY THROUGH THURSDAY... Forecast Confidence High.
Dry high pressure will settle over the Great Lakes region for the
latter half of the week. Cyclonic flow aloft will linger over
southern WI on Wednesday, so we can expect scattered to broken
diurnal cumulus clouds. Clouds will probably be more widespread on
Wednesday than on Thursday, since mid level ridging will be moving
overhead later in the week.
Winds will be light so a lake breeze is expected each day. 925mb
temps will be around 10 to 12C. The dry air and sunshine will allow
for max temps in the upper 60s inland. Thursday will be the warmer
day of the two.
FRIDAY THROUGH SATURDAY... Forecast Confidence High.
A mid level trough will drift across the Midwest on Friday and
Saturday. Precip with this upper low will stay just to the south of
the WI border, although high clouds will be possible over the area.
Winds will become a little more easterly as the low passes to our
south. This will keep lakeshore temperatures cooler once again.
Inland temps are expected in the lower 70s.
SUNDAY THROUGH MONDAY... Forecast Confidence High.
A high amplitude ridge will set up over the center of the country
and extend into the Great Lakes region. Southern WI will transition
into southerly flow which will help to bring temperatures into the
mid 70s inland. A lake breeze is still expected, but it should be
more delayed than the previous days, so lakeshore temps will have a
chance at hitting 70, or at least the upper 60s.
MONDAY NIGHT AND TUESDAY... Forecast Confidence Medium.
The upper ridge will begin to break down over the upper Midwest as
low pressure moves into the northern Plains. Southern WI should be
able to tap into some Gulf moisture which will lead to shower and
thunderstorm chances for next week.
Any lingering isolated showers/sprinkles and the accompanying VFR
cloud cover should exit to the south with the slow moving cold
front/surface trough early this morning. Steep low-level lapse rates
on forecast soundings indicate good potential for shallow scattered
to broken diurnal cumulus development inland late this morning and
afternoon, with few clouds in the far east with northeast winds
bringing cooler and more stable air off of Lake Michigan. Could
see a few sprinkles but potential too low to mention at this time.
VFR conditions as skies clear with light winds overnight into
Wednesday morning as high pressure settles over the state. Could
see patchy frost by Wednesday morning away from Lake Michigan.
Looking for gusty northeast winds today as high pressure builds into
the region behind a departing cold front, but the gusts will
remain below small craft advisory levels. Winds will lower as the
high settles over the western Great Lakes region through the
middle of the week.
LM...SMALL CRAFT ADVISORY until 10 PM CDT this evening for LMZ645-646.
TODAY/TONIGHT AND AVIATION/MARINE...99
Wednesday THROUGH Monday...99