Weather Lookup

Key Messages

- some widely scattered rain showers overnight into predawn sunday morning, mainly near the wi/il border. Otherwise, predominantly dry weather through the rest of the weekend.

- unsettled weather pattern will impact the area monday through wednesday, bringing widespread rainfall and a few thunderstorms.

- unsettled weather may continue into the end of the week before dry conditions take hold next weekend.

Short Term

Issued 1040 PM CDT sat oct 31 2026

Sunday and sunday night:

Through the predawn hours sunday morning, an area of scattered showers and isolated weak thunderstorms (currently over north- central il) is expected to continue making some northward progress, perhaps eroding slightly on the way into wi. As such, portions of southern wi (particularly near the il border) could see some sprinkles or brief rainshowers. A stray rumble of thunder cannot be completely ruled out yet. From dawn sunday morning through sunday night, the moisture and cloud cover left over from this activity may be enough for some isolated sprinkles, but that's about all we can expect given the lack of forcing for ascent.

High temps in the low/mid 60S expected this afternoon, with some upper 60S possible in the event of sunshine / mixing. Light southeast winds expected as high pressure continues eastward across the mid atlantic conus. Though mostly cloudy skies are expected for much of sunday and sunday night, some synoptic subsidence could create a period of mostly sunny skies at some point from midday to evening.

Sheppard

Long Term

Issued 1040 PM CDT sat oct 31 2026

Monday through saturday:

A high-amplitude trough in the 500-300 mb jet over the rocky mountains sunday night will slowly track eastward, with increasingly diffluent flow on it's east edge. Strong surface low pressure develops beneath this (NE colorado) and tracks northeastward toward eastern south dakota by monday evening. Working with the departed high pressure system over the mid atlantic conus, this system will drive breezy south winds and strong waa across wi on monday. Waa-driven rain showers are expected to build eastward into southern wi throughout monday (35-90% chances), overspreading the region and continuing monday night through tuesday in the warm sector of this system (75-100% chances). 18Z GEFS and ECMWF-ens guidance continues to hint at some weak mucape entering the region through this period, so we can't rule out a few thunderstorms mixing in with the widespread rainfall. Very few ensemble members allow sufficient mucape for thunder during the day monday, but we introduce slight thunder chances to the forecast monday night into tuesday as ensemble membership for mucape increases. Given that even the more aggressive ensemble members are in the ballpark of 1,000 joules, we project instability to be too weak to support strong thunderstorms. That said, the presence of any convective updrafts could lead to some brief locally-heavy downpours. Ensemble mean PWAT is around 1.3" monday, increasing to around 1.6" monday night into tuesday coincident with a healthy llj overhead. Not expecting any widespread flooding threat at this time given the antecedent dry weather. Nbm QPF totals for the synoptic rainfall are around 0.3-0.7 inches with this system monday-tuesday, and any higher totals would likely be localized to the vicinity of any healthier updrafts / thunderstorms.

The warmth with this system is expected to peak on tuesday, with highs around 70 degrees in the forecast. The mke and msn daily high temp records are 74 and 76 degrees (respectively) for nov 3, so not quite 'record breaking' yet, but certainly well above normal for this time of year.

From tuesday night onwards, model solutions begin to diverge, and the forecast becomes less certain. Some model solutions rapidly weaken the low or eject it northeastward, with the weakened / departed low forcing a cold front across southern wi. Other solutions stall the low in or around wi. Both of these scenarios would continue the aforementioned shower / storm chances midweek (50-70% rain chances), and both could lead to continued rain chances for the late half of the work week either via lingering frontal baroclinicity or a lingering cutoff-low respectively (20-45% rain chances).

The general model consensus is relatively dry and quiet conditions next weekend in the wake of this system, though predictability is low.

Sheppard

Aviation

Issued 1040 PM CDT sat oct 31 2026

Predominantly dry and VFR conditions expected through the taf period, with light south to southeast winds and overcast to broken cloud cover creating VFR ceilings (around 7,000 ft agl on average, generally at or above 4,000 ft). Some isolated sprinkles of rain will be possible at times, and a few patches of MVFR ceilings have been observed. Best shot at a stray rain shower would be through the overnight hours / predawn sunday morning, included as a prob30 for taf sites near the wi/il border. Potential for an isolated sprinkle of rain then lingers sunday into sunday night, but confidence is too low for inclusion in any taf at this time.

Sheppard

Marine

Issued 1040 PM CDT sat oct 31 2026

Open waters / synopsis: 30.5 inch high pressure will linger over the mid atlantic conus through sunday, gradually weakening and retreating east into the atlantic ocean thereafter. This will allow light south to southeast winds to continue across the lake through sunday night.

Low pressure near 29.4 inches will develop over eastern colorado sunday evening, progressing into the upper mississippi river valley into early tuesday morning. Southerly winds will steadily become gusty ahead of the approaching low, approaching or exceeding gale force over at least the central third of the lake on tuesday. Anticipate that headlines will become necessary in later forecasts.

Winds could remain breezy at times through midweek as 30.1 inch high pressure slowly builds into the canadian great plains. The track of the aforementioned low pressure system is not yet certain; we could continue to see some breezy southerly winds midweek if it lingers near wi, or transition to northwest (or even due north) post-cold-front wind flow if it exits northeast. In either case, modest north winds are looking likely late this week as high pressure drifts east into ontario canada.

Nearshore zones: a prolonged period of small craft advisory conditions is expected monday into wednesday, with some gales possible on tuesday. Gusty south winds and high waves are expected.

Additional periods of advisory conditions are possible for the late half of the work week, though forecast confidence in wind speed and direction remains low for now.

Sheppard