textproduct: Des Moines

KEY MESSAGES

- Snow ending in central and southern Iowa before sunset

- A bitter cold night and start to Sunday with wind chill values of 15 to around 30 below zero. Cold Weather Advisory is in effect.

- Turning milder and dry to start the week.

DISCUSSION

Issued at 110 PM CST Sat Dec 13 2025

The so called caboose in our clipper express shortwave train is moving into Iowa this afternoon with a 125 knot 300mb jet stream overhead. This is pushing the forcing for today's snow out of the state as large scale subsidence moves in. Snowfall reports so far today have been between 2 to around 5 inches and largely within or near the Winter Weather Advisory that ends at 3pm. Following behind the snow, a large zone of Arctic high pressure will move down from the Canadian Rockies and be centered over western Iowa by sunrise Sunday. With fresh snow, a mainly clear sky, and light winds, this will foster a bitter cold morning with feel like temperatures ranging from the teens below zero in southwest Iowa to around 30 below in northern Iowa. The Cold Weather Advisory overall continues to look good as far as placement and timing.

As the high pressure slides off to the southeast through Sunday, surface flow will become from the south and strong low level warm air advection will spread over the northern Plains. While the forcing is rather impressive, forecast soundings show a lot of dry air thanks to the departing Arctic high so forecast will remain dry. With ridging pushing the jet stream north of the state, milder air will arrive. The first part of next week will therefore be dry and have above normal temperatures likely by Tuesday and certainly Wednesday with varying degrees of melting of the existing snowpack. A shortwave trough moving over the southern Canadian prairies Tuesday into Wednesday will send a cold front into the state. While there is appreciable forcing, forecast soundings still indicate an overall dry column unsupportive of widespread precipitation. A more amplified shortwave trough will push east from the Pacific Northwest Wednesday into the upper Mississippi River Valley on Thursday with an associated 985mb-ish surface low pressure somewhere north of Iowa. While timing and placement of the synoptic features remains in flux this far out, a window of precipitation is possible for some portions of Iowa.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1131 AM CST Sat Dec 13 2025

Snow will be ending early this afternoon and with clouds clearing from north to south, a return to VFR conditions is forecast. Breezy winds from the northwest will diminish into this evening and become light and from the south by late in the period.

DMX WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory from 6 PM this evening to 10 AM CST Sunday for IAZ004>007-015>017-023>028-033>039-045>050-059>062- 073>075-084>086-095>097. Winter Weather Advisory until 3 PM CST this afternoon for IAZ023-033>036-044>049-058>062-073>075-085-086-097.