textproduct: Des Moines

KEY MESSAGES

- Red Flag Warning in the southwest today for critical fire weather conditions. Near-critical conditions near the warning area.

- High Wind Warning for gusts 60+ mph tonight. High Wind Watch issued south for possible expansion today.

- Significant winter storm will impact the region Sunday. Northern Iowa has the highest confidence in local impacts at this time, with the highest impacts still residing in Minnesota and Wisconsin.

SHORT TERM /THROUGH SATURDAY/

Issued at 353 AM CDT Thu Mar 12 2026

Overnight objective analysis showed dew points in the low 20s just across the Missouri River. As the surface ridge pivots away, this dry air will begin to leak into Iowa along the strong southwest flow that sets up today. No expansion to the Red Flag Warning overnight as cloudiness will limit some of the afternoon mixing in the area today. That being said, RH values near the existing warning may still drop below 30% today and gusts over 30mph will be common. Burning in and near the warning area is highly discouraged today. Trends will be monitored for potential expansion this afternoon.

The other story in the short term is the winds themselves, especially as we move into tonight. Winds in the afternoon will be borderline Wind Advisory in the south. This is in response to the enhanced low-level jet ahead of the deepening low in North Dakota and into northern Minnesota. The warm sector wind max will be over 40kts in the afternoon and increase to near 60kts overnight. Lift, cloud cover, and WAA will combat momentum transfer here, so have refrained from a Wind Advisory for now. Still, it's possible that gusts over 40mph will occur this afternoon, mainly across the southern half of the state. The stronger winds come with a passing cold front tonight. While it will shove the warm sector jet away, the wind max associated with the parent low will park over the northern half of the state after sunset. Meanwhile, the CAA and pressure rises from subsidence point to very windy conditions overnight. Some of the model soundings tonight have favored an initial push of high winds with the front followed by a more sustained period of winds after 06z with a secondary push of CAA. The inversion simulated in between is shallow and will also be fighting the density push of rain-cooled air, so not currently expecting much reprieve. The wind max and pressure gradient move out by late morning Friday. No changes made with the High Wind Warning on this issuance, but have expanded the High Wind Watch further south to capture the anticipated effects of the evening fropa. Uncertainty remains in how strong winds will be as southern Iowa sits far from the winds max and tighter pressure gradient. Best case, the watch is replaced with an Advisory later. Nonetheless, winds of this speed will meet the caliber winds of a severe thunderstorm and bring a risk of damage to trees and power lines. 70mph wind gusts are not out of the question in northern Iowa, particularly as the front passes.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Issued at 353 AM CDT Thu Mar 12 2026

A significant winter system is forecasted for this weekend. A seasonally strong upper-level jet max will intensify off the coast of the PNW early Saturday and begin to quickly deepen a trough residing over the Rockies. Trends over the last 24 hours have been a slightly southern shift as the jet will dig deep, generating height falls on the order of around -25 dam by Sunday night. Thermal ridging ahead of time will advect in above freezing surface temperatures over at least the southwest half of the state. The warm sector in southern Iowa will be convective to start the day. A warm layer exists aloft for much of the state to start and could offer a transition from rain to freezing rain until the warm layer is ushered out by the dynamic low. The transition to snow looks to occur Sunday afternoon. An intense band of snow will set up somewhere in Northern Iowa and into Southern Minnesota (this region will have almost all snow for this event) then heavy snow will set up on the backside of the low. With this continued snow will be high winds pushing similar values to Thursday night. The most notable difference between the GFS and Euro camps is when the TROWAL will form (culprit of the west flank snow) with the Euro offsetting this precip axis into eastern Iowa and northern Illinois. A solution such as the GFS brings that heavy snow over Iowa instead, bringing most of the area into play for Winter Storm impacts -- some potentially significant. At this time, confidence is highest in the northern band of snow that sets up early and there will likely be watches hoisted to account for this portion of the event. Monitoring trends closely for central and southern Iowa. Anticipate significant travel impacts in the region Sunday.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1042 PM CDT Wed Mar 11 2026

The light wintry precipitation that dropped into northwest Iowa has left enough moisture for patchy fog close to SLB. Not advertising any visibility reductions at the terminals with VFR conditions expected to prevail until late Thursday afternoon. Winds have diminished this evening, but will become from the southwest and south Thursday with sustained winds of 20 to 30 knots and gusts of 35 to 40 knots in the afternoon hours. Winds will back off a bit, but remain elevated into the evening as a front moves through the state. This front will bring rain chances across northern into eastern Iowa. FOD and DSM are closer to the edge so have used PROB30 until confidence increases while VFR -RA is shown at MCW/ALO, though may need to lower into MVFR. Surrounding the front will be strong low level winds; however, this setup favors turbulence overall with perhaps just a brief period of low level wind shear as the front moves through. Behind the front, strong, gusty winds from the west and northwest will ensue around and after 6z.

FIRE WEATHER

Issued at 230 PM CDT Wed Mar 11 2026

Dew points in the low 20s were analyzed just west of the Missouri River Valley. These will be ushered into southwest Iowa through the day along a low-level wind max. RH values will drop into the mid to upper 20s, the lowest within the Red Flag Warning area. No expansion to the warning overnight as cloud cover may still inhibit mixing this afternoon. Still, high fire danger exists near the warning area, and an expansion may be needed if conditions warrant.

DMX WATCHES/WARNINGS/ADVISORIES

High Wind Warning from 10 PM this evening to 7 AM CDT Friday for IAZ004>006-015-016-023>025-033>035-044>047-057>059. High Wind Warning from 10 PM this evening to 10 AM CDT Friday for IAZ007-017-026>028-036>039-048>050-060>062. Red Flag Warning from noon today to 9 PM CDT this evening for IAZ044-045-057-058-070-071-081-082-092-093. High Wind Watch from this evening through Friday morning for IAZ070>072-081>083. High Wind Watch from this evening through Friday morning for IAZ073>075-084>086.