textproduct: Des Moines

KEY MESSAGES

- Elevated to critical fire weather conditions for snow free areas on Friday. Warmer as well, especially in snow free areas.

- Light snow streaks over northern Iowa on Saturday.

- Wintry precipitation trending southward later Sunday into early Monday, but placement challenges within the state remain.

- Milder into next week with additional precipitation chances - mainly rain - possible.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 305 PM CST Thu Feb 26 2026

Early afternoon RGB imagery is providing useful remote sensing this afternoon as we try to assess the snowpack area and how much it may impact high temperatures on Friday. The dusting to around an inch of snow that fell last night has mostly melted outside of what fell on the southwest to northeast swath of snowfall. This latter swath is more continuous from around the I-35 counties into northeastern Iowa, which lines up with higher snow depths from COOP observers and NOHRSC analysis. This is an area where temperatures have been kept below initial National Blend of Models (NBM) using NBM50th and NAM. Meanwhile, farther west of I-35, the snowpack is not as continuous with a more speckled look on RGB imagery and with lesser snow depths. With wet bulb temperatures above freezing over this western area this afternoon, this will allow for more melting today into tomorrow so have stayed the course with the initial NBM for highs here as well as in snow free areas of northwestern, north central, and southern Iowa. These areas should have highs reach well into the 50s and over southern Iowa into the 60s to near 70 degrees. In addition to the warm conditions, winds from the southwest will be breezy ahead of a cold front that will be approaching and moving through the state on Friday. The winds will allow for entraining drier air to the surface and have trended the dewpoint forecast toward the 25th percentile in the afternoon. This results in relative humidity values falling below 30% in southern Iowa. Given the exposed, cured fuels in southern Iowa and pairing with the stronger winds and gusts in our southeastern forecast area, have issued a Fire Weather Watch for Friday afternoon. Depending on depth of mixing and resultant winds and RHs, this area may need to be expanded farther west.

In the wake of the cold front Friday night into Saturday, our flow will become more northwesterly with upper level kinematic forcing and low and mid-level QG convergence spreading over the area. This should help to saturate the column with 850-700mb frontogenetical forcing aiding in a band of snow moving quickly over southern Minnesota and northern Iowa from early Saturday exiting by sunset Saturday. Liquid totals are between a tenth and two tenths of an inch in the band so 1 to 2 inches of snowfall will be found in this band. This band may be quite narrow as high pressure moves into North Dakota and northern Minnesota funneling drier air on the north side of the precipitation shield.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 305 PM CST Thu Feb 26 2026

As the high positions itself over the Great Lakes on Sunday, isentropic lift on the 295K surface will occur and increase cloud cover and bring a chance for wintry precipitation to the region later Sunday into early Monday. Surface and low level wind fields point to east-northeasterly or easterly winds directing drier air into the lower part of the atmospheric column. Cross sections show this quite well and the challenge is the placement of the high and how far north to south in the state this precipitation may be pushed. The overall trend seems to be southward in much of the guidance, but certainly not all. This trend is supported by recent runs of the AIGFS and would place some snow in southern Iowa. Conversely, there is the latest Canadian ensemble as well as the AIFS, which continues its northward trend. This outcome, which seems less likely due to the high position to the north of Iowa, would bring snow farther north into Iowa and may allow for a wintry mix in far southern Iowa.

As this system departs the area, the first of at least two shortwave troughs will push into the region Tuesday into Wednesday. The flow ahead of this trough will be southwesterly allowing for milder conditions and generally favoring liquid precipitation, though some snow may mix in initially. The next shortwave trough will be more amplified and arrive late in the week and as it does, another round of moisture transport should lift into the region with additional rain chances. Ahead of both shortwave troughs, there are indications in the deterministic and AI solutions of some level of instability into the region so that will be something to monitor as we head into next week.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1051 PM CST Thu Feb 26 2026

VFR conditions are forecasted across all sites through the period. However, given calm winds, clear skies, and additional humidity from afternoon snow melt, potential for shallow fog development is being monitored. Fog has reduced visibilities at KALO, and this may continue several more hours into the overnight. A front will pass through the state midday tomorrow, bringing with it northerly turning winds and higher gusts. Gusts over 20 kts are more likely where the snow has melted. Confidence has increased for low level shear of at least 40 knots ahead of the front and has been added to all sites around 13z-16z.

DMX WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from noon to 6 PM CST Friday for IAZ082>086- 092>097.