480 FXUS63 KMKX 010237 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 937 PM CDT Sat Apr 30 2022 .UPDATE... (Issued 937 PM CDT Sat Apr 30 2022) A few showers or sprinkles may linger tonight as low pressure slowly moves from the IA/MN border into northwest Wisconsin. Should see lows tonight a few degrees above normal under mostly cloudy skies and breezy winds. DDV && .SHORT TERM... (Issued 145 PM CDT Sat Apr 30 2022) This Afternoon trough Sunday: The main focus remains on severe potential across southern and southeastern Wisconsin this afternoon and evening. Partial clearing this afternoon across our south and into parts of Illinois has allowed temperatures to warm nicely into the 60s across southern Wisconsin, and 70s across parts of central and north central Illinois. A wedge of warmer and more moist air should build into the area over the next few hours, resulting in modest instability over the region. The current SPC Day 1 Slight Risk outlines this area nicely, and matches very closely with local thinking regarding the area under the greatest severe risk. There is growing concern for a conditional tornado threat with either 1.) low topped supercells within that narrow warm sector this afternoon, and/or 2.) small linear segments surging northeasterly, presenting a QLCS tornado threat. Both low level helicity and 0-3 KM bulk shear vectors are favorable. In addition, if we're able to get enough sunshine and realize some low 60s dewpoints across the warm sector, there will likely be a decent reservoir of low level CAPE available, adding to the favorable tornado environment. How much CAPE will be available is not entirely clear right now, however. The tornado threat will be maximized with any storms moving along or across the warm frontal boundary. Beyond the tornado threat, large hail will be possible given decent mid level lapse rates, though limited instability will likely keep the largest sizes in the quarter to half dollar range. The straight line wind threat is also somewhat limited given the thermodynamic situation; the greatest potential will likely come from any broad mesovorts and surging line segments. The severe threat is expected to peak between about 3 and 7 PM, before the occluded front eventually overtakes the warm sector and convection pushes off to the east. Partial clearing is expected overnight tonight as mid level dry air builds in. More low level clouds will develop for Sunday as the upper low approaches, along with scattered showers. Look for highs on Sunday to top out in the low 50s, with gusty west winds. Boxell && .LONG TERM... (Issued 145 PM CDT Sat Apr 30 2022) Sunday night through Saturday: The upper level trough will push east of the area Sunday night, with a pleasant day expected for Monday, with highs in the upper 50s. More rain arrives for Tuesday as another system moves by to our south. Highs will be chilly, with upper 40s to perhaps 50 expected. A fairly active pattern will continue through the end of the week, with systems moving through every other to every third day or so. Temperatures will remain on the cool side, with highs running about 5 to 8 degrees below average for the first week of May. Boxell && .AVIATION... (Issued 937 PM CDT Sat Apr 30 2022) Ceilings down to around 500 ft are likely in the east for a couple/few more hours due to lingering higher moisture and southeast winds off Lake Michigan. Winds will become more south to southwest overnight, which will result in improved ceilings for a time. Meanwhile, MVFR to IFR ceilings will gradually move in from the west tonight into Sunday morning and then persist through the day Sunday and likely into Sunday night. May see a few light showers or sprinkles at times tonight into Sunday. DDV && .MARINE... (Issued 145 PM CDT Sat Apr 30 2022) Low pressure along the Iowa and Minnesota border will continue to move east tonight, reaching northern Wisconsin by Sunday morning. Occasional gales will continue across the central portion of the lake into tonight, and a Gale Warning continues until late tonight for locations south of a line from Rock Island Passage to Charlevoix and north of a line from Winthrop Harbor to South Haven. Gusts of 35 to 40 knots are expected in this area. Far northern and southern portions of Lake Michigan are only expected to see gusts to 30 knots. Also during this time there is a chance for thunderstorms, with a few strong storms possible across the far southern portion of Lake Michigan this evening. For the nearshore, a Gale Warning is also in effect for locations north of Port Washington, with a Small Craft Advisory south. Late tonight into Sunday winds will turn to the south then southwest and become lighter. High pressure then slowly builds into the area for Monday. Boxell && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Gale Warning...LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-LMZ643-LMZ669- LMZ671-LMZ673-LMZ675-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 until 1 AM Sunday. Small Craft Advisory...LMZ644-LMZ645-LMZ646 until 7 AM Sunday. && $$ 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