Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
954 FXUS63 KMKX 121455 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 955 AM CDT Wed Mar 12 2025 .KEY MESSAGES... - Warming temperatures are expected today into Friday. For well inland areas, highs in the 50s are expected today, with lower 60s Thursday, and lower 70s on Friday. Much cooler temperatures are anticipated with onshore winds closer to Lake Michigan during this period. - Widespread showers (90 percent chance) and scattered thunderstorms are forecast for Friday night, with showers lingering into Saturday, as strong low pressure and its associated frontal boundaries pass through the region. - Some strong to severe storms are possible late Friday into Friday night, mainly toward south central Wisconsin. There are still uncertainties with moisture return and timing of any boundaries. Will continue to monitor potential as this period draws closer. && .UPDATE... Issued 955 AM CDT Wed Mar 12 2025 Forecast remains largely on track as of mid-morning. Trimmed dew points back slightly through this afternoon, particularly near Lake Michigan, where persistent east-northeast winds will limit moisture returns. Continue to expect highs in the low to mid-50s away from Lake Michigan, with readings staying in the 40s closer to the water. A few locations along the immediate shoreline may remain in the upper 30s. Quigley && .SHORT TERM... Issued 410 AM CDT Wed Mar 12 2025 Today through Thursday Night: High pressure will remain well east of the region today into Thursday. Dry conditions are expected during this time, with east to southeast winds today gradually weakening. Light winds tonight will become east to southeast on Thursday. Middle to high clouds will continue to push east through the region this morning, with more sunshine expected this afternoon. Mostly clear skies tonight are anticipated, with some middle to high clouds Thursday. A warming trend will begin today and continue Thursday, with rounds of warm air advection. Highs into the upper 50s to around 60 well inland today are expected, with middle 60s well inland on Thursday. Highs could get a little higher than forecast in these areas. Onshore winds off of the cool lake waters will keep much cooler highs in the 40s today and 40s to lower 50s Thursday near Lake Michigan. Southeast winds should ramp up Thursday night, as the pressure gradient tightens with the cyclogenesis in the Central High Plains. Mild lows in the upper 30s to middle 40s should result, as warm air advection lingers. Wood && .LONG TERM... Issued 410 AM CDT Wed Mar 12 2025 Friday through Tuesday: Rapidly deepening low pressure ejects from the Colorado Rockies Friday afternoon, occluding as it propagates northeastward into the Upper Midwest. With the angle of its trajectory, expecting gusty southeasterly winds to increase through the day Friday, bringing warm, moist air into southern Wisconsin. EPS and GEFS indicate PWAT values rising to 0.75 inches in southwestern Wisconsin, and the 00Z NAM indicates agreement with that data. With the easterly component of the winds, expecting temperatures in Lake Michigan adjacent counties to be on the order of 10 to 20 degrees colder than inland areas during the afternoon hours, greatly limiting potential for any strong storms. However, farther east away from the lake influence, expecting temperatures in the lower to middle 70s. This will decrease the capping influence of strong warm air advection in the 850 to 700 mb level, and brings potential for more significant instability (most unstable CAPE of 750 to 1000 J/kg) into the evening hours. As the low occludes and continues to propagate eastward Friday night, the occluded front will lift northeastward through southern Wisconsin, bringing strong shear (0 to 3 km shear values around 35 knots and 0 to 6 km shear values 40 to 45 knots), turning from southeasterly at the surface to straight southerly near the top of the boundary/inflow layer, and cooler air to whittle away the capping inversion. However, all current modeling indicates the frontal passage after sunset, bringing instability to a minimum. Therefore, any strong to severe storms would be confined to far southwestern and parts of south central Wisconsin, where instability lines up with the highest shear. The front will continue to push northeastward, with instability waning, but shear remaining strong through the remainder of southern Wisconsin. Trends will continue to be monitored, but regardless of strength, expect a line of showers and thunderstorms to move northeastward across southern Wisconsin Friday night into early Saturday morning. After the front moves into Lake Michigan and northern Wisconsin Saturday morning, expect southerly winds to continue to strengthen as the low propagates into the Mississippi Valley. Additional rounds of showers and isolated thunderstorms are possible during the afternoon hours ahead of winds shifting to become northwesterly and bringing in colder air Saturday night as low pressure lifts into Ontario. Wrap-around precipitation may bring light rain showers and snow showers to southern Wisconsin into Saturday night (15 to 25 percent chance), with precipitation chances diminishing into Sunday. Colder northwesterly flow continues through Sunday, before the next wave of warmer air sets up on Monday and continues into Tuesday. MH && .AVIATION... Issued 955 AM CDT Wed Mar 12 2025 VFR conditions prevail through the period at all terminals. Currently breezy conditions will begin to taper moving into this afternoon. Quigley && .MARINE... Issued 410 AM CDT Wed Mar 12 2025 High pressure around 30.3 inches in southern Quebec will shift east today, with easterly winds gradually subsiding. The influence of the high will linger tonight into Thursday, with light winds expected to continue. Waves may to out around 4 feet today across the nearshore waters, but conditions look too borderline at this time for a Small Craft Advisory. Strong low pressure around 28.9 inches is then expected to develop in the Central High Plains on Thursday night, bringing increasing southeasterly winds. The strong low pressure system will move into the Central Great Plains on Friday, then shift northeast into Iowa Friday night and across Wisconsin and Lake Superior on Saturday. Expect increasing south to southeast winds across Lake Michigan Friday into Friday night. A warm front will push northward across the region Friday night, bringing rain and chances for thunderstorms. Expect gusty south to southwest winds on Saturday, gradually veering southwest Saturday night and west by early Sunday. Gales are possible Friday night and Saturday, especially over southern portions of the lake. The cooler lake waters may limit gusts somewhat, but the strength of the low may override this. A Small Craft Advisory is likely Friday into Saturday night for the nearshore waters, with the gusty winds associated with the strong low moving through the region. Wood && .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