Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
537 FXUS63 KMKX 160901 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 401 AM CDT Thu May 16 2024 .KEY MESSAGES... - Scattered thunderstorms are expected from late morning into the early evening. Some could be strong to severe with small hail and gusty winds as the main threats. A marginal risk (1 out of 5) has been issued for most of southern WI. - Summer-like temperatures and mostly dry Fri-Sun. - A wet and unsettled period for Mon-Tue. && .SHORT TERM... Issued 400 AM CDT Thu May 16 2024 Today through Saturday: A shortwave trough slightly amplifying and digging into MN will move across the nrn half of WI today then lift newd into Ontario tnt. At the surface, the warm front approaching the MS river will quickly lift into central WI this afternoon then stall as a weak wave of low pressure moves along it. A weak sfc trough/wind shift will then follow for late afternoon and early evening over srn WI. A plume of PWs of 1-1.2 inches and MUCAPE of 1000-1500 J/KG is expected for the afternoon along with deep layer shear of 30 kts. At this time it still appears shower and storm development is likely with moist low to mid levels resulting in little to no capping, in addition to the lift from a meaningful band of PVA extending south from the main shortwave trough. Additional isolated development will be possible during the early evening along the weak wind shift. The aforementioned CAPE and shear combo would support marginal conditions for SVR storms with any short segment lines that may develop or possible supercell structures. Fog may then become a concern tnt especially where any meaningful rain occurs as the sfc trough dissipates and good radiational cooling conditions develop where clearing occurs. Weak high pressure will then prevail over Lake MI Fri-Fri nt with 500 mb height rises over the Great Lakes. Any fog should quickly burn off Fri AM followed by summer like temps away from the lake. Temps will then warm into the lower 80s well inland from the lake for Sat as an upper ridge builds over the Great Lakes in response to an occluding low over Manitoba. Gehring && .LONG TERM... Issued 400 AM CDT Thu May 16 2024 Saturday night through Wednesday: Filling low pressure is trending northward due to a nose of high pressure nudging in from the central Plains on Saturday night, leading to diminished chances for rainfall along an associated cold front. Still, an isolated shower or thunderstorm is possible in west-central Wisconsin during the evening to overnight hours before the frontal feature weakens. Dry and sunny conditions with light northerly winds are then expected through Sunday, leading to temperatures near 80 degrees across much of southern Wisconsin. Light winds may lead to a lake breeze component, keeping shoreline counties cooler. Developing low pressure in the central and northern Plains then brings a weak warm frontal feature through southern Wisconsin late Sunday night into Monday, with showery activity increasing into Monday morning. Low pressure follows general steering flow northward around the surface high, bringing chances for thunderstorms throughout Monday afternoon as the surface trough pivots slowly eastward. A wet, warm pattern continues through Tuesday as additional shortwaves propagate northeastward along the previously initiated trough. As high pressure retreats eastward on Wednesday, expect precipitation to exit. However, wrap around precipitation may produce a few additional showers through Wednesday. Gehring && .AVIATION... Issued 400 AM CDT Thu May 16 2024 Bkn035-050 cumulus or stratocumulus and scattered showers and storms will develop from west to east this morning into the afternoon as a warm front followed by a weak cold front moves through the region. Local MVFR Cigs are possible during this time including restricted Cigs and Vsbys in and near storms. The storms will linger into the early evening over ern WI before ending. Afterward, areas of fog is expected to develop over srn WI especially over far ern WI where it could become dense. Gehring && .MARINE... Issued 400 AM CDT Thu May 16 2024 Light east to northeast winds early this morning will veer to east to southeasterly later this morning and last through the day. This will occur as a weak trough of low pressure moves across Wisconsin then dissipates over the lake tonight. Weak high pressure will then prevail over the lake Friday and Friday night. Areas of dense fog will be possible over the lake tonight into Friday as a relatively humid airmass flows over the cold waters. Gehring && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee