Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
254 PM CDT Tuesday Sep 23 2014
Tonight and Wednesday...forecast confidence is high.
High pressure to the east of the region will continue to bring quiet
weather to the area tonight and Wednesday. Light winds are expected
overnight...though winds at the top of the inversion remain in the
15 knot plus range. So...any light fog will be limited to river
valleys and low spots. Lows tonight should bottom out in the upper
40s inland to lower 50s Lakeside.
Models showing 500 mb shortwave trough sliding slowly eastward
toward the area later tonight into Wednesday. Some middle to high
clouds associated with this feature should move into the western
counties gradually. Dry air in the lowest 5000 to 7000 feet should
preclude any precipitation from falling in the far western counties.
Highs should reach the lower to middle 70s away from Lake Michigan once
again on Wednesday. Onshore winds by early afternoon will limit
highs to around 70 near the lake...before falling into the 60s
during the rest of the afternoon.
Short term...Wednesday night through Friday.
Wednesday night...forecast confidence high.
Models have come into good agreement with bringing the weakening
plains short wave right into Wisconsin Wednesday night. Strongest
forcing is associated with differential vorticity advection per 500-
300mb q-vector convergence forecasts...mainly Wednesday night. With
dry flow around broad surface high to the east...layers below 5k feet
never saturate in the west...with the dry layer deepening to the
east. Will limit slight chance probability of precipitation to the far west and far
northwest. Expect only isolated light showers or sprinkles with
mainly trace amounts.
Thursday through Friday night...forecast confidence high.
Models all retrograde the remnant vorticity maximum that is over the state
early Thursday back towards the Central Plains Thursday night and
Friday as a broad 500 mb high builds into the western Great Lakes.
Will ignore the splotchy light quantitative precipitation forecast on GFS and European model (ecmwf) over eastern County Warning Area
Thursday morning as forecast soundings are extremely dry below 10k
feet...with little to no upward motion. Will see quiet weather with
warm temperatures for the rest of the work week...though a bit cooler
near the lake...but all areas will be above normal for this time
Long term...Saturday through Tuesday. Forecast confidence high.
Quiet...pleasant weather continues through the weekend as ridging
holds in place into next week...with a persistent but dry south-
southeast flow around the western flank of the eastern surface high
into the western Great Lakes. Temperatures remain above normal
through the period. Only GFS brings any light precipitation with a
weak back-door cold front/surface trough south of the u.P./WI border
Sunday night...and it wipes the precipitation out before it reaches the far
northern County Warning Area. Next chance for showers holds off until next Tuesday
night/Wednesday with weak surface trough.
VFR conditions are expected tonight and Wednesday across taf sites.
High pressure to the east of the region will bring quiet weather to
the area. May see light fog in low lying areas and river
valleys...but taf sites should remain fog Free.
Lake breeze will turn winds southeast late this afternoon at the
eastern sites...with south winds at Madison. Winds will remain south
to southeast tonight into Wednesday at taf sites...becoming
southeast Wednesday afternoon.
Tonight/Wednesday and aviation/marine...wood
Wednesday night through Tuesday...rem