Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 252021
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
321 PM CDT MON JUL 25 2016
.TONIGHT AND TUESDAY... Forecast confidence is high.
Expect patchy fog overnight as high pressure drifts across the
region. Clear skies, calm winds, small dewpoint depressions, and
recent moisture will lead to patchy fog in open areas. Areas of fog,
possibly dense, are possible in river valleys and low lying areas.
Winds will be light on Tuesday. Dry air overhead will allow for
plenty of sunshine, aside from a few diurnal cumulus clouds. Expect
a lake breeze during the late morning and afternoon to keep
temperatures near the lake a little cooler. 925mb temps should be
about 2 degrees warmer than today, so that means high temperatures
will be just a notch warmer as well.
.WEDNESDAY AND THURSDAY...Forecast confidence is medium.
There will be precip and thunderstorm chances throughout this time
period as series of shortwaves move across the region. The best
chance is Wednesday afternoon and evening when there is good
agreement with 700-500 ascent ahead of a weak shortwave. A weak
westerly low level jet will sag southward into the region bringing
an increase in moisture on Wednesday. PWs increase to at about 1.6,
90% of normal, so heavy rain is possible with any thunderstorms.
.FRIDAY THROUGH MONDAY...Forecast confidence is medium.
There continue to be major differences among the synoptic models
about whether a surface low will move across southern part of the
state late in the week. The ECMWF has been consistent showing it
moving across northern IL bringing widespread precipitation while
the other models have been consistently drier with the system much
weaker and further south. Model consensus results in chance pops for
Friday and Saturday. There is limited cape during the overnight
hours especially near Lake Michigan but there is too much
uncertainty this far out to disregard any thunder chances.
Wisconsin is under NW flow at the mid levels as a ridge/trough
pattern sets up over the conus. Highs around 80 are expected for the
later half of the week. Mid level ridging then moves into the plains
and starts to shift into Wisconsin for the early part of next week
bringing dry weather and warmer temperatures.
Surface high pressure over the Upper Midwest will lead to clear
skies and calm winds across southern Wisconsin overnight. Expect
patchy fog to develop, so some IFR/LIFR likely in low areas,
VFR conditions will resume by mid Tuesday morning with a few late
morning and afternoon fair weather cumulus.
High pressure drifting across the upper Great Lakes will keep winds
light through Wednesday. A lake breeze is expected each day.
Northeasterly winds in the wake of a weak cold front on Thursday
will lead to higher waves along the nearshore waters. Waves are
still expected to remain below small craft advisory criteria.
TONIGHT/Tuesday AND AVIATION/MARINE...MRC
Tuesday NIGHT THROUGH Monday...Marquardt