textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Temperatures continue to trend well above normal through the end of the week.

- Chances (about 30 to 50 percent) for light rain or drizzle in southeast Wisconsin Wednesday late afternoon/evening, with rain likely (about 50 to 70 percent chances) area wide Christmas night.

- Very slight concern for freezing rain toward central WI Christmas night.

SHORT TERM

Issued 200 PM CST Tue Dec 23 2025

Tonight through Wednesday night:

Quiet tonight into the day Wednesday as large scale ridging and surface high pressure remain overhead. However late in the day Wednesday we will start to see some embedded shortwave energy slide through southern WI in addition to some low level WAA. While midlevel moisture will be limited the expectation is for the midlevels to gradually moisture as precip falls through the column. Late Wednesday afternoon we should start to see some showers to the west moreso associated with the low level WAA but will likely be lighter. As this feature slides east the chances will gradually increase and become a bit more widespread. Generally CAMs show a scattered nature to the precip thus we will keep PoPs limited to 30-50% at this time. Precip is also expected to be all rain.

Precip will push out late Wednesday night as drier low level air swings back in fairly quickly behind the system.

Kuroski

LONG TERM

Issued 200 PM CST Tue Dec 23 2025

Christmas Day through Tuesday:

Strong high pressure passing by to the north of the region Christmas Day should bring quiet weather with increasing northeast to east winds. Mild high temperatures in the middle to upper 30s are anticipated.

The 500 mb ridge axis shifts across the region and flattens out somewhat Thursday night into Friday. There are weak vorticity maxima that shift east through the region at times during this period. There is some weak warm air advection in the low levels Thursday night into Friday morning, helping to moisten and saturate this layer per area forecast soundings. During this time, the middle to upper levels remain fairly dry, negating any ice crystal formation.

Thus, the precipitation types that occur Thursday night into Friday morning will depend on the surface temperatures. The modest warm air advection should allow for temperatures to slowly rise Thursday night into Friday morning. Any potential for light freezing rain or drizzle probably would occur later Thursday night in far northern portions of the area, where temperatures will be the slowest to rise above freezing. Mainly light rain is expected otherwise during this period.

For now, will maintain a short period of a wintry mix in far northern portions of the area later Thursday night, then change to mainly rain Friday morning. Any light freezing rain/drizzle would cause slick roads for holiday travelers, so will be keeping an eye on this period for potential messaging.

Any precipitation should move out of the area by Friday afternoon, with mild highs in the upper 30s northeast to the middle 40s south expected in the afternoon. 500 mb cluster analysis and another round of warm air advection suggests the ridge will remain just east of the area and will help keep the mild temperatures into Saturday. Highs into the 40s are anticipated.

Cluster analysis at 500 mb then favors a closed low shifting southeast through the region Sunday into Monday, with a strong cold front moving through later Saturday night. This will bring strong cold air advection on gusty northwest winds behind the front into Monday night. Temperatures should drop below seasonal normal values during this period, with wind chills dropping below zero by Sunday night. Temperatures may modify into the rest of next week, though uncertainty rises with larger spreads in ensemble temperatures.

Wood

AVIATION

Issued 200 PM CST Tue Dec 23 2025

VFR CIGS expected throughout tonight with light to modest northwest winds turning northeasterly. This evening there is some model guidance suggestive of a small area of MVFR CIGS this evening toward west central WI but looks temporary and limited in scope. In addition, near the lake may feature another chance for a brief period of MVFR CIGS likely associated with some light east winds off the lake providing some low level moisture and thus clouds. Both of these would appear likely to only last a few hours this evening and Wednesday morning. The next best chance for MVFR conditions would be later Wednesday/Wed Night as system pushes through bringing largely scattered light rain showers to southern WI.

Kuroski

MARINE

Issued 200 PM CST Tue Dec 23 2025

Northwest winds this afternoon with turn more easterly tonight and southeasterly into Wednesday, as high pressure swings through tonight. Winds turn back northerly later Wednesday night as another high pressure system swings through south central Canada. Winds turn back easterly as the high pushes east through Christmas day. Southeast winds expected Thursday night/Friday with a weak low pressure system passes likely south of the Lake Friday. Light and variable winds behind the system. Thursday night into Friday may be a bit breezy with Small Craft conditions expected for a period.

The next best chance for gales is early next week Sunday through Monday with increasing chances, with high higher end gales possible as well. This will be a result of a weak low passing through with strong high pressure system impinging from the west causing a strong pressure gradient and thus strong northwest winds.

Kuroski

MKX WATCHES/WARNINGS/ADVISORIES

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