textproduct: Des Moines

KEY MESSAGES

- Extreme Cold Warning tonight through noon Friday for dangerous wind chills of 25 to 40 below zero.

- Cold Weather Advisory noon Friday through 3 am Saturday.

- Light snow possible late Friday night into Saturday, mainly for southern Iowa.

DISCUSSION

Issued at 233 PM CST Thu Jan 22 2026

An Arctic cold front has reached northwest Iowa this afternoon. Temperatures have been steadily falling behind the boundary with readings still falling over northern portions of North Dakota and Minnesota where temperatures are now falling below 20 below zero along with wind chill values of 40 to 50 below zero. The 850 mb cold core near -39C is now moving over that area. All of this Arctic air is plunging south with some minor modification tonight. Still the -30C temperatures will clip far northern Iowa late tonight into Friday morning. Surface temperatures will fall well below zero across the entire area from the single digits below zero south to near 20 below over the far north. These temperatures combined with northwest winds of 12 to 20 mph will result in wind chill values in the upper 20s to low 40s below zero with the coldest north to warmest south. Therefore, an Extreme Cold Warning is in effect through 18z Friday then transitioning to a Cold Weather Advisory. Arctic high pressure will be moving across southern Minnesota late Friday into Friday evening before gradually shifting east after midnight. Theta-e advection aloft will start moving over Iowa from southwest to northeast and this should result in increasing clouds which will provide some positive impact on low temperatures which along with lighter winds, will result in wind chills rising above advisory criteria. This is why the advisory ends at 3 am Saturday morning.

Horizontal convective rolls/shallow snow showers are ongoing across a large portion of central/southern Minnesota behind the cold front. This has resulted in visibilities dropping to near 1sm at times in that area. Some of this activity may move into northern Iowa later this afternoon and evening. So far, gusty winds over 35 mph in northern Iowa is not resulting in reduced visibilites and part of that is due to much of the existing snow pack being put into storage with Wednesday's wind. Brief periods of reduced visibilites are possible with the snow showers. KMCW just dropped to 1/2sm with snow.

Continue to evaluate light snow potential late Friday night and Saturday as the theta-e advection continues to stream into Iowa and the precipitation shield with the southern storm system expands north. Have maintained snow chances into central and southern Iowa with some uncertainties on northward extent due to residual dry air from the departing Arctic high. At this time, Interstate 80 is a good cutoff for accumulating snow potential and this likely will be dependent is the surface wind origination is from the departing high or if it can turn more easterly.

The main message beyond Sunday is the several waves of cold advection yet in the extended. This will keep temperatures mostly below to much below normal. The NBM is maintaining dry conditions but analysis and pattern recognition point to a few periods with light snow, see HCRs today which again often accompany Arctic intrusions. The NBM rarely captures this.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 552 PM CST Thu Jan 22 2026

MVFR cigs possible at northern sites over the next 4 hours, but will be fairly transient to begin. Then VFR cigs return. Gusts up to 25kts possible overnight, gradually tapering off by 12z. Midlevel OVC deck arrives in the planning period.

DMX WATCHES/WARNINGS/ADVISORIES

Extreme Cold Warning from 9 PM this evening to noon CST Friday for IAZ004>007-015>017-023>028-033>039-047>050. Cold Weather Advisory from noon Friday to 3 AM CST Saturday for IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097. Extreme Cold Warning from midnight tonight to noon CST Friday for IAZ044>046-057>062-070>075-081>086-092>097.