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Area forecast discussion 
National Weather Service Milwaukee/Sullivan WI
353 PM CDT Friday may 29 2015

Tonight and Saturday...forecast confidence - high.

On and off showers with a few storms will continue this afternoon
and overnight. Current activity may wind down for a time later this
afternoon...with more showers/storms moving in from the west in the
evening and night hours and a cold front drops southeast into the
area. The cold front will make it down to about the
Madison/Milwaukee areas by daybreak Saturday...crossing the WI/Illinois
border early morning. More showers and maybe a couple storms will
persist through the morning on the back side of the surface low as
the upper trough moves through. Models have slowed down overall...so
raised probability of precipitation for tomorrow. Should see rain wind down northwest to
southeast late morning into the afternoon.

Still a marginal risk for severe storms per Storm Prediction Center...though have not
seen much of concern so far...and instability will generally
decrease through the evening hours. Something to keep an eye on
though.

Temperatures will crash late tonight into Saturday morning as the cold
front moves through...with a cool Saturday in store for southern
Wisconsin...especially near Lake Michigan. Lingering cloudy skies
and breezy north to northeast winds will add a bit more of a chill
in the air as well.

Saturday night through Monday...forecast confidence - high.

Low to middle-level q-vector convergence exits southeast WI early
Saturday evening as breezy northeast winds continue to feed drier
air across southern Wisconsin. Lingering evening cloudiness should
clear...succumbing to dry air onslaught. A cool night is expected
with 925h temperatures falling to 4-5c. With clear skies...overnight temperatures
will fall into the upper 30s to lower 40s most areas. A few
susceptible locations will fall into the middle 30s. However due to
lingering boundary layer mixing...not expecting any frost formation
late Saturday night.

Cool air remains in place through Sunday into Sunday night before
warming trend commences. Lighter boundary layer winds and continued
dry atmosphere will allow temperatures to fall into the middle 30s to lower
40s Sunday night. Pending amount of upstream high cloud cover that
works into southern WI...may be some patchy late night frost in
susceptible areas Sunday night.

Monday night through Friday...forecast confidence - medium.

No surprises from 24 hours ago. Central Continental U.S. Large-scale ridging
expands into upper Midwest early in the period resulting in warming
trend and quiet conditions through Tuesday. Some concern about
potential short wave moving eastward across Continental U.S./Canadian border Tuesday
night and Wednesday. Increasing southerly winds will allow column precipitable water to
increase to over 0.50 inch. Medium range guidance diverges on
strength and placement of this wave...with more consistent European model (ecmwf)
much weaker than GFS and Gem. Medium range guidance in better
agreement on large scale ridge re-expanding into the upper Midwest
around Thursday. Stronger middle-level short wave looks to flatten
ridging across the upper Midwest Thursday night and Friday. Hence this
period looks to have best chance for more widespread convection.
Daytime temperatures will remain on the warm side for much of the
extended period. However Lakeshore areas will remain cooler due to
a prolonged period of S to southeast winds.

GFS 5-day 500h means continue to show west to southwest steering
flow through the first week of June and above normal heights. Hence
expect warmer than normal temperatures for much of the period with good
growing conditions and little frost threat.

&&

Aviation/00z tafs/...

Current showers/storms may wind down for a time later this
afternoon...with more convection moving in from the west in the
evening and night hours and a cold front drops southeast into the
area. The cold front will make it down to about the
Madison/Milwaukee areas by daybreak Saturday...crossing the WI/Illinois
border early morning. Expect a fairly quick shift and increase in
the winds as the front moves through.

More showers and maybe a couple storms will persist through the
morning on the back side of the surface low as the upper trough
moves through.

Outside of moderate to heavy rainfall...VFR conditions will likely
persist into this evening. Expect lower ceilings to move in overnight as
the cold front moves through. Should see rain wind down northwest to
southeast late morning into the afternoon...with slowly improving
ceilings as drier air works into the area.

&&

Marine...

North to northeast winds will become gusty Saturday morning behind a
departing cold front. Gusts to 30 knots are expected on Saturday.
Winds will ease a bit Saturday night and Sunday...but the pressure
gradient looks to be tight enough to keep gusts to 25 knots going
through the day Sunday. A Small Craft Advisory is thus being issued
this afternoon for Saturday through the day Sunday.

May seem some fog at times this evening into tonight given the moist
airmass over the cooler waters. So far though...the nearshore areas
seem to be remaining mainly free of fog. Something to keep an eye on
until the cold front moves through late tonight into Saturday
morning.

&&

Beaches...

High swim risk conditions are expected on Saturday. Strong north to
northeast winds will bring life threatening waves and currents along
the Lake Michigan shore. A hazard is not being issued to due cold
air temperatures...but for those that venture out...it is advised to
stay out of the water Saturday and Saturday night.

&&

Mkx watches/warnings/advisories...

WI...none.
Lm...Small Craft Advisory 12z/30 through 00z/01 lmz643>646.

$$
Tonight and Saturday/aviation/marine/beaches...ddv
Friday night through Thursday...mbk

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