textproduct: Sioux Falls

KEY MESSAGES

- Stronger winds will return by Thursday with gusts 45 to 55 mph expected overnight. Pockets of higher (60+ mph) are also expected mainly north of I-90. A High Wind Warning is now in effect for southwestern MN and portions of southeastern SD north from 7PM Thursday to 7AM Friday.

- High to Very High fire danger (locally extreme) is expected by Thursday as strong winds and lowering humidity values return to the area. A Fire Weather Watch remains in effect along and south of a Huron to Sioux Falls to Spirit Lake, IA line from Noon through 9PM CDT.

- All interested parties should monitor the forecast for next weekend. A more organized storm system in the Northern Plains may impact travel, and will bring much cooler temperatures to begin next week.

DISCUSSION

Issued at 310 PM CDT Wed Mar 11 2026

CURRENTS & TONIGHT: Another cool day continues! Taking a look across the area, mostly clear conditions persist this afternoon as temperatures approach the mid 30s to low 40s across the area. While this has succeeded in melting most of the snow, still have a light snow pack across portions of far southeastern SD and northwestern IA. With this in mind, have slightly decreased temperatures for the day with most areas topping out in the upper 30s to upper 40s with the mildest conditions across southcentral SD. Shifting gears to precipitation, we're starting to see a few sprinkles to light showers develop mostly along the Highway-14 corridor mainly in response to the arrival of a shortwave. However, much of this won't reach the ground due to a dry sub-cloud layer according to soundings. Lastly, another cool night is ahead with lows mainly in the low to mid 20s.

THURSDAY: Looking into Thursday, things will get pretty interesting aloft as a decently strong clipper wave crosses into the Northern Plains and Great Lakes regions bringing strong winds, light rain, and lower humidity values at times. Starting with the precipitation, a strong surface warm front will progress through the area on the nose of jet streak. This combined with a little bit of isentropic lift should lead to scattered showers developing across areas mainly north of I-90 between the afternoon and evening. While accumulations of 0.10" of an inch or less are expected, can't completely rule out a few hundredths across northwestern IA as well. Next, a well-mixed environment along with increasing mid-level warm air advection (WAA) will lead to temperatures in the 50s to mid 60s for the day with the warmest conditions across the Missouri River Valley. This combined with lower RH values will likely lead to some elevated fire weather concerns on by Thursday afternoon (more details in the fire weather section).

Finally, we'll shift over to the main concern which are the stronger winds. A tightening SPG along with an approaching cold front will lead to increasing southwesterly to westerly winds between Thursday afternoon and Friday morning. Given the mixy environment and strong LLJ (85-95 mph at 700 mb), wind gusts between 45-55 mph with pockets of 60+ mph are expected across most of the area. With this in mind, decided to upgrade part of our High Wind Watch to a High Wind Warning mainly north of a Tyndall to Canton to Spirit Lake, IA line. Anything south of the line was kept in a High Wind Watch. The current thinking was to upgrade the parts of the watch that we have the highest confidence of higher wind speeds. While we can't rule out additional upgrades to the watch, decided this would be a good starting point to emphasis the stronger winds.

FRIDAY ONWARDS: Heading into the extended period, an active pattern will continue aloft through at least Saturday. Persistent northwest flow will help usher in multiple system into the weekend potentially leading to accumulating snowfall on both Friday and Saturday. While some of the 11.12z guidance has started to come into better agreement with features, there is still some uncertainty as far as amounts. Nonetheless, with the potential for moderate to heavy and/or mixed precipitation make sure to monitor your local forecast heading into St Patrick Day weekend and be prepared to alter any travel plans. Otherwise, we'll get another taste of winter temperature-wise over the weekend with highs decreasing into the 20s to low 30s on Sunday and Monday.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 1235 PM CDT Wed Mar 11 2026

VFR conditions will continue this TAF periods. Taking a look at satellite imagery, mostly clear conditions will continue for the rest of the day before high clouds begin building in overnight. Otherwise, breezy northwesterly winds will become more southwesterly into Thursday to end the TAF period.

FIRE WEATHER

Issued at 310 PM CDT Wed Mar 11 2026

More elevated fire weather concerns are expected by Thursday as stronger winds and lower relative humidity values return. To start, the combination of warmer air aloft and southwesterly surface winds will lead to milder conditions with highs expected to be in the 50s to mid 60s and dew points in the upper 20s to low 30s. This will result in RH values 25-35 percent range with lowest values potentially along the Missouri River Valley. Between this and increasing southwesterly to westerly surface winds with gusts between 30-40 mph winds, high to very high (and locally extreme) fire danger are expected through the early evening. As a result, our fire weather watch looks to be in good shape at first glace.

While there have been talks with neighboring offices about a potential upgrade to Red Flag Warning, decided to keep our watch in place for now due to a few factors: 1. portions of far southeastern SD and northwestern IA have a light snow pack which could dampen fuels affecting the ignition and spread of potential fires. 2. Building cloud cover could hamper how fast we warm and affect overall temperatures for the day. 3. Some high resolution guidance is now timing in the rain faster (early afternoon) as opposed to late afternoon/early evening which could affect how many hours we truly meet criteria. Without knowing how all these factors will play out, decided the best course of action would be a wait and see approach. Thus the watch remains in effect.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Fire Weather Watch from Thursday afternoon through Thursday evening for SDZ038-050-052>055-057>071. High Wind Watch from Thursday evening through Friday morning for SDZ066>071. High Wind Warning from 7 PM Thursday to 7 AM CDT Friday for SDZ038>040-050-052>065. MN...High Wind Warning from 7 PM Thursday to 7 AM CDT Friday for MNZ071-072-080-081-089-090-097-098. IA...Fire Weather Watch from Thursday afternoon through Thursday evening for IAZ001>003-012>014-020>022-031-032. High Wind Watch from Thursday evening through Friday morning for IAZ001>003-012>014-020>022-031-032. NE...Fire Weather Watch from Thursday afternoon through Thursday evening for NEZ013-014. High Wind Watch from Thursday evening through Friday morning for NEZ013-014.