textproduct: Des Moines

KEY MESSAGES

- Snow developing this afternoon and evening. A band of 1 to 3 inches is possible over parts of central Iowa. Little to no precipitation northeast.

- Freezing drizzle may develop over parts of central and south central Iowa late this evening and overnight.

- Temperatures warming again Thursday and Friday. More precipitation possible through the weekend and into next week.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 410 AM CST Wed Feb 25 2026

The primary forecast challenge of the day remains the system arriving over Iowa later today and tonight. Surface high pressure is moving east/southeast across the Northern Plains and into northern Iowa. This system has been ushering in lower dew points into the the state. The initial short wave energy that will impact Iowa is now moving over Montana and towards South Dakota. Surface low pressure over Oklahoma and Texas continues to suppress the low level Gulf Moisture well to the south. The upper level jet is stretched from Iowa to northwest into Montana and Wyoming. The mid-level Pacific moisture stream is nearly co-located with the upper level jet. Both will be settling south today and it is that Pacific moisture that will be mostly relied on to attempt saturation. Strong isentropic lift will develop as the short wave approaches Iowa. The isentropic ascent will be strongest between 900 to 700 mb, which shows up well along the 285K-290K surfaces. This forcing also shows up well in the theta-e advection within this pressure layer. Several challenges with this system remain. The strongest forcing arrives early with much of this energy used up in the hydrometeor loading of dry air below and the saturation process. Second, the impact of the dry air reinforcing from the high pressure that will be moving into northeast Iowa today. Third, the period with dendritic growth zone (DGZ) forcing is limited before the forcing becomes more focused on sub DGZ and less favorable SLRs as snow crystal morphology transitions to plates. Fourth, there will likely be a more focused band of snow and still expect spatial adjustments and likely more narrowly focused than currently forecast. Five, mid-level drying with the short wave passage may lead to the loss of ice introduction and potential freezing drizzle development late this evening and into the overnight hours. That potential looks south of Highway 30 at this time(ie south of Carroll/Ames/Marshalltown). At this time, expect a snow band of 1-2 inches, perhaps a few 3 inch amounts. Not planning a headline at this time for the snow. The headline maker could be freezing drizzle if it materializes. Confidence in location and actual impact remains low enough to remain headline free for that as well. This is a dynamic forecast and will adjust as needed.

Thursday and Friday look warmer but the NBM remains way too warm, assuming some snow cover remains in addition to any new snowfall. Pulled highs back on Friday.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 257 PM CST Tue Feb 24 2026

Another wave passing through the Great Lakes region will bring westerly flow aloft and southerly flow at the surface, resulting in warmer conditions on Friday. This will be a good setup for warm temperatures with the clear skies and compressional heating aloft, but extensive snowpack likely still in place will work to hold high temperatures down during the day. Current NBM highs in the mid to upper 50s over the current snowpack are likely too high, as the snow will actively cool the air as it melts. Expect this to dial back over snow covered areas in the coming days. That said, areas without snow will likely warm quite substantially and dewpoints near or above freezing should make a healthy dent in the snow pack.

At least low end precipitation chances then develop Saturday through the beginning of next week as a wave passes to the north of the area on Saturday and another, potentially more prominent system passes through toward the end of the weekend or early next week. However, the current precipitation forecast is likely overdone temporally as NBM tries to capture differences in timing with these systems in the models. With such spread in guidance, it's not worth speculating on a specific time, but main takeaway is at least an active pattern continuing through the end of the weekend and into next week.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 538 AM CST Wed Feb 25 2026

Conditions will deteriorate today mainly this afternoon and overnight as clouds increase and cigs lower along with increasing precipitation chances. The main band of snow is expected to impact KFOD/KDSM/KOTM with much lower chances at KMCW/KALO. The snow may transition to freezing drizzle late this evening and overnight. MVFR to IFR cigs are possible with the precipitation. Areas of fog may develop overnight along with further and perhaps more widespread IFR to even LIFR cigs late. Northwest wind early in the period will become light this afternoon and transition to southeast overnight.

DMX WATCHES/WARNINGS/ADVISORIES

None.