Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 260826
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
326 AM CDT FRI AUG 26 2016
.TODAY AND TONIGHT...Forecast confidence is medium.
High pressure will move across WI today although scattered to broken
cirrus will occur due to swly flow aloft and the upstream
convection. The high clouds will probably keep temps down a degree
or two along with an afternoon lake breeze as well. Highs in the mid-
upper 70s for today.
For tonight, a shortwave trough will track from NE to srn MN. A wave
of low pressure will follow into IA with a sly 30 kt LLJ moving into
srn WI. The models differ on the exact placement of the LLJ with
some focusing farther west than others. Confidence is such to go
with likely PoPs over south central WI with high chance PoPs in ern
WI. PWs will rise to 1.5-1.8 inches with the thetae advection while
elevated CAPE will be very minimal due to mid level lapse rates of
5.5-6.0 C/KM. The showers and storms that do occur should have
moderate to heavy rainfall rates but will likely be brief.
Showers/storms will be likely across southern Wisconsin Saturday
as the first wave lifts northward. This first round may be limited
to the morning...with a break possible late morning into the
afternoon between waves. Another wave may then bring more storms
late afternoon into the evening. Overall, models not in great
agreement with timing and placement of convection. Though
confidence is on the higher end that there will be showers/storms
on Saturday, not nearly as confident in the timing at this point.
Should see near normal temps on Saturday.
.SUNDAY THROUGH THURSDAY...Forecast confidence...Medium
Deeper moisture will be south of the area on Sunday, so went
mainly dry. Should be a pleasant day.
Near zonal flow Monday will transition to northwest flow between a
ridge building to the west and an upper low passing through well
to the northeast. Could see a couple weak waves move through the
forecast area...so kept some pops going into mid-week.
By Wednesday, the ECMWF and Canadian push the bulk of moisture
and instability south and west of the forecast area. The GFS
remains moist and unstable Wed and Thu. Kept some pops per the
GFS, but would be dry if the ECMWF/Canadian solutions pan out.
Should see temps a bit above normal through Tuesday. There is less
certainty beyond that due to the previously mentioned model
differences for Wed/Thu. Generally kept temps in between the
warmer GFS and cooler ECMWF/Canadian solutions.
VFR conditions today and this evening with only sct-bkn cirrus today
with a mid level deck of clouds for the evening. After midnight,
scattered to numerous showers and tstorms are expected to develop as
a warm front approaches from the sw. Cigs will lower and may become
MVFR toward sunrise or afterward. Cigs and vsbys will be reduced
with any showers and storms.
Relatively light winds and low wave heights are expected for today
and the weekend over the western shore of Lake MI. A lake breeze is
expected this afternoon with esely winds continuing tonight and
TODAY/TONIGHT AND AVIATION/MARINE...Gehring
Saturday THROUGH Thursday...DDV