Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
356 PM CDT Thursday Oct 23 2014
area of rain showers will continue to move east through the rest of
the area...exiting the far eastern counties early this evening. This
was being driven by a 500 mb shortwave trough pushing into the area
from the west.
Area of low stratus clouds and fog will move into the area from the
west this evening...and should linger later tonight into early
Friday morning. Area forecasts soundings showing a moist airmass
lingering later tonight into Friday morning...with light winds later
This will be especially true in the far western and northwestern
counties. This should help dense fog develop here later tonight into
Friday morning...where a dense fog advisory has been posted. Some
dense fog may occur further east across the rest of the area...so
this will need to be monitored by later shifts. The dense fog
advisory may need to be expanded eastward later on.
The fog and low stratus should dissipate by late morning on
Friday...with some sunshine through the rest of the day. This should
allow for highs to reach into the middle 60s across most of the area.
Friday night- confidence...medium
NAM is showing light quantitative precipitation forecast with warm air advection ahead of a surface
trough. Other models hint at quantitative precipitation forecast. NAM soundings indicate drizzle
possible with moist profiles up to 2-4k feet. Looks marginal so kept
Saturday and Sunday - confidence...high
Surface high pressure moves from the northern plains to Illinois.
Strong northwest flow will bring gusty winds...dry air and clear skies.
Expect surface temperatures in the low to middle 60s Sat and upper 50s to
lower 60s sun. 500mb ridge axis passes overhead on sun before flow
Monday through Tuesday night - confidence...low
Strong low level jet ahead of organizing low pressure system brings
warm moist air into the region. Highs in the middle to upper 60s. Low
pressure expected to move from the north-Central Plains into
northern WI by Tuesday morning. Precipitation starts Monday morning with a break
likely midday. GFS indicates evening and overnight precipitation winding
down Tuesday morning. European model (ecmwf) is slower and delays the second round of
rain until Tuesday and lingers it into the evening hours. Hence
significant uncertainty with timing of precipitation but expect a period of
moderate rain showers at some point with this system. Kept chance of
thunder. Cold front expected to move through Tuesday morning or
afternoon per the slower European model (ecmwf).
Wednesday to Thursday - confidence...medium
There is better agreement for dry conditions Wednesday. Latest European model (ecmwf)
hinting at some light precipitation for Thursday.
area of rain showers with a few MVFR visibilities are expected to
push east through the eastern taf sites through early this evening.
Light winds are expected during this time.
Fog with ceilings and visibilities down to alternate minimums will
develop by middle to late evening...and linger through the rest of
tonight into early Friday morning. Low levels remaining moist with
light winds will help the fog and low stratus.
Dense fog with visibilities of 1/4 mile or less are possible at
Madison and the eastern sites between 01z and 15z Friday...but left
at 1 mile in tafs for now due to some uncertainty. Later shifts will
need to monitor potential.
Light southwest winds are expected Friday...with scattered to broken
cumulus clouds by the afternoon.
a tight pressure gradient should develop on Saturday and linger into
Saturday evening...between low pressure well northeast of the
region...and high pressure over the northern plains.
Brisk west to northwest winds are likely during this time...with
frequent gusts to 25 knots. A Small Craft Advisory may be needed.
High waves should remain over the open waters...due to the offshore
nature of the winds.
Brisk winds may bring high waves to the nearshore waters on
WI...dense fog advisory from 1 am to 10 am CDT Friday for wiz046-047-
Tonight/Friday and aviation/marine...wood
Friday night through Thursday...marquardt