Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 220237
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
937 PM CDT SUN AUG 21 2016
.UPDATE...High pressure and clear skies to continue tonight with
forecasted low temps in the lower 50s on track just inland from
Lake MI. Sly winds and warm advection to then develop by late
Mon am and continue into Wed. No appreciable clouds or rain
chances until late Tue nt and Wed when a shortwave trough moves
across the region.
.AVIATION/06Z TAFS/...Mostly clear skies and VFR conditions for
Mon-Tue. A few fair wx cumulus each afternoon.
.MARINE...A ridge of high pressure will move across Lake MI Mon am
with it moving ewd for the afternoon. Sly winds will then prevail
into the middle of the week with 10-20 kt wind speeds each
afternoon. Waves will build to 2 to 3 feet from Port Washington
.PREV DISCUSSION... /Issued 301 PM CDT SUN AUG 21 2016/
TONIGHT AND MONDAY...Forecast Confidence...High
Showers in the northeast forecast area will wind down late this
afternoon and early evening as daytime heating is lost. Clouds will
also decrease during this period, with mostly clear skies expected
tonight and Monday as high pressure builds into the area.
May see a little fog tonight, but given current dewpoints and
forecast low temps, confined the fog mention to the Wisconsin River
Temps will be below normal tonight, but will recover to around
normal tomorrow as southerly winds develop within the western
portion of the high.
MONDAY NIGHT THROUGH FRIDAY...Forecast Confidence...Medium
Southern WI will be under the influence of southwest flow through
Tuesday as high pressure moves towards the east coast. This will
bring warmer temperatures into the region.
Moisture advection increases Tuesday night in advance of a 500mb
shortwave. The models are in fair agreement showing periods of
precip beginning Wednesday morning with the shortwave and lingering
through the evening before a cold front moves through. Rain could be
heavy at times with PW values around 1.7 inches, which is at the
90th percentile for this time of year. The more conservative ECMWF
and Canadian models show a minimum few hundred MU CAPE so kept the
chance for thunder.
High pressure starts to push in Thursday then dominates for Friday.
With the frontal passage Wednesday night temperatures will be cooler
for the rest of the week.
SATURDAY THROUGH MONDAY...Forecast Confidence...Low
The latest ECMWF has backed off from its previous run with low
pressure and widespread precipitation. It now looks more like the
GFS with precip chances at times due to shortwave activity and a
developing low early next week. There are is a big difference with
instability between these models so have a chance of thunder which
is indicated by the GFS.
Showers are likely in the northeast into late afternoon, winding
down pretty quickly late afternoon and early evening as daytime
heating is lost. Skies should turn mostly clear for tonight as high
pressure builds in.
A little fog is not out of the question later tonight, though
nothing widespread is expected.
VFR conditions are expected under the high on Monday.
Winds will be somewhat lighter tonight and Monday as high pressure
moves into the region. Could see winds/waves approach Small Craft
Advisory levels Wednesday ahead of approaching low pressure.
TONIGHT/Monday AND AVIATION/MARINE...DDV
Monday NIGHT THROUGH Sunday...Marquardt