Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 142015
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
315 PM CDT FRI OCT 14 2016
.TONIGHT AND SATURDAY...Forecast Confidence...Medium
Southern Wisconsin should see mainly high clouds into the evening
hours. Lower clouds are expected to advect into the area later
tonight though. These clouds are just to the west/southwest of the
state and models are in pretty good agreement with low level
moisture, so confidence is increasing in this cloudy setup. Skies
will stay less cloud covered longer in the east tonight, so went the
Temps aloft will continue to warm on Saturday under a low level jet.
Unfortunately, model soundings suggest the clouds may stick around
most of the day, which would greatly limit the heating potential.
Even so, it`ll be a warm enough airmass for above normal highs in
the the upper 60s. If by chance there are breaks in the clouds
tomorrow afternoon, temperatures would likely end up a few degrees
warmer than currently forecast given how mild it will be aloft.
There will be a chance for showers in the northwest tomorrow
afternoon as moisture and instability continue to increase ahead of
approaching wave. Even with the clouds in place, looks like enough
instability to mention thunder chances by late afternoon.
.SATURDAY NIGHT...Forecast confidence is medium.
A cold front will push out of Minnesota and into southern
Wisconsin this period. MUCAPES should be in the 800-1000j/kg
range early, especially west of Madison, falling off to the east
as the night wears on. Most of this CAPE will be elevated anyway.
Deep layer shear is around 30-40kts. SPC has us in a marginal risk
and given the above parameters, this seems appropriate. The wind
fields through the column are quite strong, so it won`t take much
to mix down some gusty winds.
.SUNDAY THROUGH MONDAY...Forecast confidence is medium.
The front will weaken and stall near or along the WI/IL border on
Sunday, then head back north as a warm front Sunday night as a
strong low pressure system forms out to the west. Other than the
possibility of lingering light stuff in the morning across the
southeast on Sunday, much of the day looks quiet and warm with
highs in the lower to mid 70s. It`s possible a thicker cloud deck
could keep us a tad cooler, but not bad for mid October. As the
front heads north it`s accompanied by a mid level short wave
headed northeast. This should help trigger another round of
showers and storms, but mainly over the northern half of the
forecast area. The core of the low will generally stay to our
north, so we`ll have lingering chances of showers and storms over
the nrn part of the forecast area through about Monday evening.
.TUESDAY THROUGH FRIDAY...Forecast confidence is medium.
We`ll be in a fast zonal mid level flow around mid week with the
main storm track up to our north. This should keep southern
Wisconsin on the dry side of things for Tuesday and Wednesday. As
we get into Thursday, we start to see a deep mid level trough
carve out somewhere over the Rockies or Central Plains. This is
where the ECMWF and the GFS diverge. The GFS is digging a large
closed low over the central Rockies by Thursday, while the EC has
a more progressive open wave over the Central Plains, moving east
across the Great Lakes. This introduces plenty of uncertainty for
the later periods of the forecast. For now, the next chance of
rain would be Wednesday into Thursday due to the potential of
ECMWF solution working out. The GFS keeps ridging over the Upper
Midwest as the big upper low out west will be slow to kick out.
Overall, the week ahead is looking very mild for mid to late
VFR conditions will persist into tonight as high pressure departs to
the east. Models are in pretty good agreement that stratus will
develop by later tonight...and this seems reasonable given the
clouds just to the west and southwest of Wisconsin. MVFR ceilings
are likely, possibly IFR for a time. The low clouds will probably
linger through much of the day Saturday, though increasing southerly
winds should improve mixing and hopefully raise cloud bases through
It will remain dry through tonight, with a few showers developing
west Saturday afternoon. Could be some thunder by late afternoon.
The primary line of showers/storms is expected to move through Sat
evening and overnight.
Continued mention low level wind shear in the TAFs tonight. Best
chance will be in the northwest half of the forecast area under the
stronger winds aloft.
Increasing southerly winds between departing high pressure and an
approaching low will bring continued Small Craft Advisory conditions
to the north, with advisory conditions developing across the rest of
the nearshore waters this evening. Gusts to 25 knots at times along
with high waves will linger into Saturday night. The highest waves
will be in the northern marine zones due to the southerly wind flow.
LM...SMALL CRAFT ADVISORY from 10 PM this evening to 4 AM CDT Sunday
SMALL CRAFT ADVISORY until 4 AM CDT Sunday for LMZ643.
TONIGHT/Saturday AND AVIATION/MARINE...DDV
Saturday NIGHT THROUGH Friday...Davis