Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
204 FXUS63 KMKX 151504 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1004 AM CDT Wed May 15 2024 .KEY MESSAGES... - Next round of showers and storms expected for Thursday afternoon into Thursday evening. Some could be strong, but coverage will be scattered. - Warming trend into the weekend with just chances of rain and a few rumbles of thunder. && .UPDATE... Issued 956 AM CDT Wed May 15 2024 No major changes to the going forecast today. Keeping an eye on tomorrow as morning runs of the CAMs are depicting a better environment for a strong storm or two tomorrow afternoon into the evening as we`ll see a wedge of a warm sector in Wisconsin between an advancing warm front and cold front. We`ll have more details with the afternoon AFD. CMiller && .SHORT TERM... Issued 346 AM CDT Wed May 15 2024 Today through Friday night: Scattered stratus over far srn WI will dissipate later this morning as low pressure weakens as it moves ewd across the Ohio Valley, and nly winds bring drier air into the region. Otherwise the sfc ridge will remain over WI today before shifting ewd tnt. Temps will return to the upper 60s to lower 70s well inland with near 60 at the lake front. A weak sfc low and upper level trough will move from MN to wrn Lake Superior on Thu. PWs will increase to 1-1.2 inches with very marginal instability, but increasingly moist soundings. The HREF and GFS/ECMWF support likely PoPs from west to east through the day as the trough passage extends south into the area. Scattered showers to then linger into Thu nt with the weakening sfc trough passage over the area and another weak shortwave trough approaching from the west. The trough will pass early Fri AM but isold showers could linger in far ern or srn WI. Some uncertainty on timing of drying for Fri which will impact cloud cover and temps. At this time counting on some sunshine with temps ranging from the 60s near the lake to middle to upper 70s over south central WI. Shortwave ridging and a dry fcst for Fri nt. Gehring && .LONG TERM... Issued 346 AM CDT Wed May 15 2024 Saturday through Tuesday: Ridging nudging northward into the Upper Mississippi Valley and steady southerly winds at the surface may lead to widespread temperatures over 80 degrees on Saturday. Modeling has come into agreement that the interplay between an Ohio Valley low and a 500 mb shortwave driven low in Canada and the northern Plains will drape a cold frontal feature through Wisconsin Saturday evening, although better forcing remains across northern Wisconsin and the UP of Michigan as upper level ridging steers the northern low into northern Canada. In addition, this upper level ridging brings in warmer air aloft and prevents instability development during the day. Therefore, kept the NBM 15 to 30 percent PoPs for this timeframe. High pressure remains prominent through Saturday night into Sunday, with an additional shortwave propagating eastward from the Colorado Rockies Sunday night into Monday and a developing low in the lee of the Canadian Rockies creating a baroclinic zone in the Upper Midwest. Plenty of uncertainty remains in exact timing and intensity of precipitation across southern Wisconsin from Sunday onward as triggers for convection transition to a shortwave-driven pattern beneath general ridging. Because of uncertainty, left NBM PoPs alone. However, there will likely be periods of dry conditions Sunday into Monday. Intrusion from the tropical jet stream into the central Plains midweek may result in enhanced cyclogenesis and therefore better chances for widespread precipitation Tuesday into Wednesday. Gehring && .AVIATION... Issued 1004 AM CDT Wed May 15 2024 VFR conditions today amid light to moderate northeasterly winds. Light winds become more easterly overnight, remaining light, with scattered high clouds moving in as well. Tomorrow, clouds increase from west to east, with scattered storm activity anticipated in the afternoon and evening. CMiller && .MARINE... Issued 346 AM CDT Wed May 15 2024 Low pressure around 29.6 inches will move across the Ohio Valley today, while the surface ridge of 29.9 inches over WI moves across Lake Michigan tonight. Modest northerly winds over the lake today will become light and variable tonight. Light to modest east to southeast winds will then develop for Thursday and Thursday evening as weakening low pressure around 29.6 inches tracks from northern Minnesota into western Lake Superior. Light and variable winds are then expected Friday and Friday night as weak high pressure develops over the lake late on Friday. 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