textproduct: Des Moines

KEY MESSAGES

- Winds continue to diminish through this afternoon and evening. Cold and dry conditions through Thanksgiving and the first half of Friday.

- Snow moves into the area Friday late afternoon and evening, continuing through Saturday before tapering off overnight Saturday. Widespread impactful snow is expected with travel impacts likely this weekend.

- Bitter cold settles in Sunday and early next week with highs in the teens to low 20s and lows in the single digits.

DISCUSSION

Issued at 222 PM CST Wed Nov 26 2025

Low pressure continues to shift off to the east this afternoon while high pressure slowly moves towards the area. Winds have diminished through the afternoon but remain breezy, especially across eastern Iowa where the pressure gradient remains tight. Winds will continue to come down this afternoon and evening as high pressure shifts into the area. High pressure remains overhead on Thursday, allowing for cold and dry conditions for Thanksgiving Day. Highs Thursday in the upper 20s north to mid 30s south with plenty of sunshine. Similar conditions are forecast to start off the day on Friday with cloud cover increasing through the morning.

The pattern and system evolution Friday and Saturday remains remarkably consistent between the GFS and Euro (and their ensembles), both with each other and with the past several runs. While this does lend itself to increased confidence in impactful wintry weather for the holiday weekend, there are still several days for the system track change and it is important to be ready for those changes. Current guidance suggests that an upper level trough will pass across the northern Rockies and undergo lee cyclogenesis on Friday. That surface low will move towards Iowa with the warm air advection wing lifting across Iowa later Friday afternoon and evening, continuing overnight. This taps into deep gulf moisture transported into the area to quickly saturate sounding profiles. There is good lift associated with this first round with around -15 to -20 microbars through the dendritic growth zone on Friday/Friday night. This results in a widespread 2-5+" of snow across northern to central Iowa by Saturday morning.

The surface low is currently set to track across the Iowa/Missouri border on Saturday with the northern deformation zone setting up across Iowa. This will slide off to the east overnight with snow end early Sunday morning. Yesterday's model runs indicated the possibility that the dry slot would result in loss of ice introduction aloft for a period of time on Saturday in southern Iowa, however this concern has shifted further south and soundings are now fully saturated through the DGZ and above. There is still the potential for a rain/snow mix in far southern Iowa where low level temperatures will be near to just above freezing. This second round will bring several additional inches of snow to the area on Saturday and Saturday night. All in all, both rounds combined have a 80-90% chance of 4+ inches of snow along and north of I-80 and 75% chance of 8+ inches of snow for highway 30 and north. Expect impacts to travel beginning later Friday and continuing through out the day on Saturday. Impact could linger into Sunday as snow comes to an end.

Even colder air filters in behind this on Sunday and through early next week. Highs in the teens and low 20s on Sunday and early next week with lows in the single digits to below zero.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1042 PM CST Wed Nov 26 2025

MVFR stratus has become more expansive than any guidance would have indicated impacting MCW and ALO as forecast, but it did expand far enough as FOD. Have continued using more observational trends for the forecast, which would suggest clearing by before sunrise at MCW and ALO. For FOD, there is an upstream area of stratus feeding down that may keep restrictions past sunrise, but confidence is medium at best. While there could be another brief period of MVFR ceilings at MCW or ALO toward midday on Thanksgiving Day, confidence is too low to include at this time. DSM and OTM will have VFR conditions through the period. After diminishing tonight, winds from the northwest will become breezy in the afternoon before diminishing in the evening.

DMX WATCHES/WARNINGS/ADVISORIES

None.