Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
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709 FXUS63 KMKX 181937 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 237 PM CDT Sat May 18 2024 .KEY MESSAGES... - Scattered thunderstorms this evening, especially northwest of Madison. Gusty winds possible. - Unsettled Monday and Tuesday with several rounds of rain/storms. - Increased risk for strong/severe storms Tuesday and Tuesday evening. && .SHORT TERM... Issued 237 PM CDT Sat May 18 2024 Rest of this Afternoon through Sunday: Temperatures have warmed into the 80s inland (70s lakeside) this afternoon, under abundant sunshine. Deep mixing has resulted in dewpoints dropping into the 50s and low 60s in many locations, with just a few high based cu. The main focus this evening will be on a cold front currently located to our northwest. This front and an associated pre- frontal trough will push into south central Wisconsin early this evening. Overall upper level support is weak, with the main shortwave moving across western Lake Superior. This, along with the deep mixing and dry boundary layer, will probably limit convective coverage along the front. That said, the dry and well mixed boundary layer will also present a threat for strong wind gusts for any organized convection that does form, given the inverted v profile. Convective coverage will decrease fairly quickly through the evening, with just a handful of showers/storms (if that) by the time the front reaches southeastern Wisconsin late this evening. Skies will clear overnight, with lows in the 50s. High pressure makes a brief appearance tomorrow, with light and variable winds and highs in the upper 70s to near 80. With the light wind profile, expect a well-developed lake breeze to move inland during the afternoon hours. Boxell && .LONG TERM... Issued 237 PM CDT Sat May 18 2024 Sunday Night through Saturday: Scattered showers and storms will develop overnight Sunday night into Monday morning as a strong low level jet noses into the area. Hail will be possible with a few of the strongest storms. Additional thunderstorms are possible during the day Monday, depending on the timing of a shortwave moving through the area. If the wave moves through during the morning as currently expected, there may be enough capping/subsidence in the afternoon to limit additional precipitation. However, a slower progression would favor more convective development in the afternoon, including the potential for a few stronger storms. Tuesday continues to look like our best chance for severe weather, though the situation remains somewhat messy and complex. Low pressure lifting through western Iowa and southern Minnesota is expected to reach western Wisconsin by afternoon and evening, with an associated warm front lifting northward through the region. Convection will likely be ongoing north of this front Monday night and Tuesday morning, but there may be enough capping south of the warm front for a break early Tuesday afternoon. The current scenario suggests that severe thunderstorms may then develop over Iowa and northern Missouri Tuesday afternoon, and move east-northeastward Tuesday evening ahead of an advancing cold front. All modes of severe weather will be possible, though the wind and spin-up tornado threat will be greatest if convection is able to congeal into an organized convective complex by the time it reaches southern Wisconsin. Ultimately, the location of the warm front and degree of instability that is able to develop Tuesday and Tuesday afternoon will be very key to the eventual severe weather threats. Drier air looks to then build into the region mid week as high pressure moves through the area, with southerly flow returning late in the week/early next weekend. Boxell && .AVIATION... Issued 237 PM CDT Sat May 18 2024 VFR will continue this afternoon with southwest winds inland, and east to southeast flow near the lake behind the lake breeze. Scattered showers and thunderstorms are expected to move through the area this evening, with the best chances north and west of Madison, and lower chances further to the southeast. Brief drops to MVFR are possible in and around these showers/storms, but otherwise VFR will prevail. Winds shift to the northwest overnight, before becoming light and variable tomorrow morning as high pressure builds in. Another lake breeze is very likely on Sunday. Boxell && .MARINE... Issued 237 PM CDT Sat May 18 2024 Southwest winds will continue this afternoon and early evening ahead of a cold front. Winds become northerly early Sunday behind the front, before becoming light and variable as high pressure moves through Sunday afternoon. Breezy southerly winds return Monday and Tuesday ahead of the next approaching low pressure system. Small Craft Advisories are likely to be needed during this time. Boxell && .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