textproduct: Milwaukee/Sullivan

KEY MESSAGES

- High temperatures remaining 10-20+ degrees above normal through Wednesday.

- Widespread round of rain (~50-80+% chances) expected Tuesday night through Wednesday morning. A few thunderstorms are possible later Tuesday night.

- More precip expected Thursday afternoon into Friday, with rain gradually switching over to all snow.

- Temperatures trending back toward normal by next weekend.

SHORT TERM

Issued 100 PM CST Sun Feb 15 2026

Tonight through Monday night:

Synopsis/Mesoanalysis: Another mild afternoon is in-progress across southern Wisconsin under mostly sunny skies. A surface ridge currently centered near the Mississippi River, will work into the region later this afternoon & evening, allowing winds to become light and variable. Winds will trend trend southwesterly after midnight as the surface ridge continues east of the area. Low pressure currently centered over Manitoba will progress into northern Ontario tonight, ultimately approaching the Hudson Bay Monday evening. The advancing low will pull an attendant cold front into the upper Mississippi River Valley in the process, with the boundary attempting to work into southern Wisconsin later Monday afternoon and evening. The approaching boundary will maintain southwesterly breezes through Monday, with resultant warm advection translating to the mildest temperatures of the entire forecast period for most. Said temps will likely challenge February 16 records at both MSN (57; 1981) & MKE (56; 1921).

Tonight: Broad warm advection will increase in the 925-700 mb layer after midnight as low pressure shifts into northern Ontario. Could see a few sprinkles within this warm advection belt during the predawn hours in central/east-central Wisconsin, where isentropic ascent affiliated with the temp advection will be a touch stronger. Don't anticipate any appreciable accumulation in any sprinkles that do occur.

Monday: Persistent southwesterly breezes will maintain warm air advection through most/all of peak heating, leading to temperatures anywhere between 10-20+ degrees above normal across southern Wisconsin. If there's one catch to an otherwise slam dunk set up for overperforming high temperatures, it would be if the approaching surface front makes it into the region faster than current modeling suggests. If a faster arrival time were to occur, temps would remain a touch cooler than the current forecast, particularly over central & east-central Wisconsin where the boundary would arrive first. Have continued to trend the current forecast toward a later frontal arrival/milder solution, but will be monitoring trends through this evening.

Quigley

LONG TERM

Issued 100 PM CST Sun Feb 15 2026

Tuesday through Sunday:

Synopsis: Originating from upper level energy currently off the California coast, an upper trough remains is forecast to eject into the Northern Plains on Tuesday, encouraging surface cyclogenesis near the South Dakota-Nebraska border during the afternoon hours. Development of the low will encourage increasing south-southeast winds across southern Wisconsin, leading to cooler (but still above- normal) temperatures relative to Monday afternoon. The surface low will progress northeast into the western Great Lakes with its parent upper trough Tuesday night into Wednesday morning, bringing a round of widespread rain to southern Wisconsin. A few embedded thunderstorms are possible, particularly from late Tuesday night into early morning hours Wednesday. Precip will gradually shut off Wednesday afternoon as drier mid-level air works into the region. Above normal temperatures will continue into Thursday, with a second disturbance forecast to bring additional precipitation to the area Thursday afternoon into Friday. Mild antecedent temps will result in precip starting as all rain, with a transition to rain/snow mix and eventually all snow anticipated Thursday night into Friday as the system pivots east & pulls colder air into southern Wisconsin. Said colder air will linger into next weekend, with daytime highs trending back toward late February normals through Sunday.

Tuesday night through Wednesday afternoon: Continue to anticipate widespread rainfall across southern Wisconsin as the first of two disturbances moves overhead. Global guidance has started to converge on a surface low track through central or north-central Wisconsin, which will place the area within low level warm advection through the duration of the appreciable precip time frame. Thus anticipating all rain across the region Tuesday night through Wednesday morning. Tied to a wing of pronounced warm advection in the 925-700 mb layer, Tuesday night/early Wednesday morning forecast soundings depict a stout warm nose beneath cooling temperatures aloft, which could translate to some elevated instability & embedded thunderstorm potential during the ~10PM - 6AM time frame. Not currently anticipating a widespread strong/severe threat in any embedded thunder, though low freezing levels would support some brief hail potential in any deeper/more robust cores. Thunder potential will wane later Wednesday morning as the warm advection wing & any elevated instability shift east of the region. Drier mid-level air will shut precip off from southwest to northeast Wednesday afternoon. If the dry air is slower to arrive, a few light snow showers could mix in with concluding rainfall across the far north, with negligible accumulation expected.

Thursday afternoon through Friday: Expect another batch of widespread precip as a second disturbance moves across the region. Mild conditions through Thursday afternoon should allow precipitation to start as all rain, with a gradual transition to rain/snow mix and eventually all snow occurring through Friday morning as cold air wraps in from the northwest. Will need to monitor for possible light snow accumulation in this system, particularly to the north of I-94 and US-18 where p-type changeover will occur earlier in the event.

AVIATION

Issued 100 PM CST Sun Feb 15 2026

VFR flight categories prevail through the entirety of the period at all terminals. Winds will trend light and variable late this afternoon & evening as high pressure moves in from the west. The high will shift east tonight, allowing winds to turn southwesterly during the predawn hours. An approaching surface front will maintain southwesterly flow into the day on Monday. Southwest flow will be stronger just off the surface ahead of the approaching boundary, leading to a period of potential LLWS near FL020 late tonight through early Monday morning. Have accounted for this potential in the 18Z update. Anticipate largely dry conditions ahead of the approaching surface boundary, but can't entirely rule out a light sprinkle or two across the north. Confidence in activity is too low to justify prevailing mentions at SBM in the current forecast, but will be monitoring model guidance and obs trends for potential TEMPO groups through tonight.

Quigley

MARINE

Issued 100 PM CST Sun Feb 15 2026

1010 mb low pressure is centered near northern Lake Michigan this afternoon, resulting in weak west-southwest winds across the majority of the waters. Currently near the Mississippi River, 1012 mb high pressure will approach Lake Michigan this evening, allowing winds to become light and variable. 1006 mb low pressure is forecast to form over the northern Mississippi River Valley tonight, allowing winds to veer west-southwesterly as the feature approaches during the predawn hours. Gusts between 20-25 knots are possible, but are expected to remain well below gale thresholds. Some patchy fog is possible over southern Lake Michigan later tonight, though dense fog is not anticipated at this time. Will continue to monitor trends through this evening. Winds will weaken later Monday afternoon into Monday night.

Stronger low pressure near 990 mb will form over the northern Great Plains during the day on Tuesday, resulting in increasing east to southeasterly winds over Lake Michigan. Winds will continue to increase Tuesday night into Wednesday as the low approaches and passes near or north of Lake Michigan, with wind directions veering southwesterly over the southern waters while remaining east- southeasterly further north. Confidence in a period of sustained gale force gusts is beginning to increase over at least the northern half of the open waters Tuesday night into Wednesday, with the need for possible headlines being evaluated in coming forecast updates. Low pressure will weaken & shift east of Lake Michigan later Wednesday afternoon into Thursday morning, resulting in a decrease in wind gusts. Rain will accompany the passing low Tuesday night through Wednesday, with a few rumbles of thunder possible south and some rain-snow mix possible further north.

Continue to expect a second area of low pressure near or below 1000 mb to develop over the middle Mississippi River Valley Thursday night, with the feature tracking over or just south of the southern open waters closer to daybreak Friday. The development and passage of the low will bring increasing northeast wind gusts Thursday night through Friday morning. A few gale force gusts are possible. Additional snow will accompany the passing low, along with some light to moderate freezing spray possible late Thursday night through early Friday. Winds will shift west-northwesterly Friday afternoon through Saturday as low pressure shifts east and 1026 mb high pressure builds into the northern Great Plains. Winds will remain northwesterly through Sunday as high pressure moves into the upper Mississippi River Valley.

Southwest winds will become breezy in nearshore zones tonight through Monday. A few gusts may approach Small Craft Advisory thresholds during this time, but are expected to remain isolated and brief enough to preclude the need for any headlines. Small Craft Advisory conditions are likely late Tuesday afternoon through Wednesday as an area of low pressure crosses near or north of Lake Michigan. A second area of low pressure remains on track to cross near or just south of Lake Michigan late Thursday into Friday, likely bringing a second period of Small Craft Advisory conditions. Will evaluate the need for headlines in coming forecast updates.

Quigley

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None.