textproduct: Sioux Falls

KEY MESSAGES

- Precipitation chances increase Monday through Wednesday. While the favored precipitation type remain liquid, confidence is also high that amounts are going to be rather light and some may see zero precipitation. At times drizzle may be possible.

- Confidence is high in another extended period of well-above normal temperatures into next weekend.

- Confidence also remains higher than normal in returning rain risks Thursday into Friday during the passage of a front. Some snow may also mix in at the end of the event.

UPDATE

Issued at 1048 PM CST Sun Mar 1 2026

Beginning to see stratus expand into locations along and east of the James River this evening. The stratus should remain in the mid levels through most of the overnight hours. The stratus will drop to the low levels by tomorrow morning. With stratus remaining in place through the day tomorrow, have knocked down high temperatures a bit. Some very light rain/drizzle is on the table for Monday evening and night as the low levels further saturate. The dendritic growth zone (DGZ) may saturate along a modest 700mb FGEN zone, leading to more light rain than drizzle as it tracks along and parallel to I-90. After this area of ascent moves through, the DGZ looks to dry out some more, leading to light drizzle across the area. With low temperatures falling to around freezing, some very light freezing drizzle is possible. If any ice accumulation were to occur, it would be a very light glaze and quite isolated.

A stronger short wave trough will eject out of the Rockies on Tuesday. The main dynamics look to remain south of the forecast area but with modestly saturated thermal profiles in place, isolated rain showers look to persist throughout the day. High temperatures look to remain above average in the upper 40s to low 50s with lows falling to the 30s. Rainfall totals for both Monday and Tuesday look to be light with amounts of a few hundredths to up to about a tenth of an inch expected each day.

Rain chances look to continue through the majority of the work week with weak to moderate forcing remaining in place. A stronger wave could bring higher chances for rain towards the end of the week. However, this is highly dependent on how this stronger wave evolves. Given the variance in this system, have stuck with the NBM for the time being.

DISCUSSION

Issued at 1218 PM CST Sun Mar 1 2026

THIS Afternoon: Variable cloud cover continues on Sunday as both a combination of mid-lvl lift develops high based alto stratus deck. Further south, low-lvl moisture is developing into a sub-1000 ft ceiling across far southern Nebraska that will become a larger player in the local weather into Monday. Temperatures with the cloud cover and light winds will only rise near the freezing mark in snow-free areas and 20s where fresh snow fell on Saturday.

TONIGHT: The passage of mid-lvl vorticity into the mid-lower Missouri River valley overnight will allow short wave ridging to reach the Dakotas overnight. The brief rise of heights is due to another wave crossing the Central Rockies. The response of these features will be the development of a channel of northeastward moisture advection through Nebraska and into the eastern half of the CWA overnight. This moisture results in an expansion of stratus northeast (most likely after midnight) as evident by rapidly decreasing CPD plots. While soundings express the stratus stays shallow, there is weak lift within the layer, so cannot completely rule out a tough of drizzle or freezing drizzle into NW Iowa and southern Minnesota by daybreak.

MONDAY: Stratus is likely to expand northeast early Monday, with favored areas of overcast skies along and east of a line from Yankton to Sioux Falls to Tracy. Elsewhere cloud cover will be more variable and with southerly flow increasing, we'll see a nice recovery of temperatures into the 40s in most areas. Some concerns about temperatures struggling over snow cover in the far north, and have tried to account for cooler temperatures in the highs. Subtle mid-lvl lift arrives in the afternoon and increases in the evening and overnight hours as mid-lvl vorticity moves east through the Dakotas. A narrow corridor of light rain showers develops over south central SD and northern Nebraska by mid-day, spreading eastward through the evening. At this point, there may only be a brief window of deep saturation, with loss of ice apparent in soundings into Tuesday. The end result may be brief period of drizzle developing.

TUESDAY-WEDNESDAY: As a deeper trough enters the Central and Southern Plains Tuesday, we may see mid-lvl ridging increase and more influence of dry northeasterly low-mid lvl flow as Tuesday progresses onward. Better low level forcing (isentropic lift) settles southward along areas of Highway 20 and southward Tuesday. With temperatures climbing into the 40s and 50s, now impactful weather is expected. Models continue to lift the upper low drifting through the Plains a bit further north today, with ensembles also showing a northward shift of measurable precipitation Tuesday night into Wednesday. Probabilities of measurable rain into Wednesday have increased to near 60+ along but especially south of I-90 towards Highway 20. This won't be a drought buster with amounts less than 0.10". Dry conditions quickly return through Wednesday morning as a surface front drifts into northern Iowa and southern Minnesota. West of this boundary, southerly winds push highs towards the upper 50s.

THURSDAY-FRIDAY: A warm and breezy Thursday is expected through the region as deep southerly surface and low level flow develops ahead of a longwave trough approaching the Rockies. 925:850 mb winds increase towards the 40 knot mark Thursday afternoon which may manifest itself into 35 to 40 mph gusts in the area through the afternoon. This upward gust probability would sit more towards the 75/90th percentile of the NBM. If we don't see any significant wetting rain conditions Tuesday, then even though dew points rise into the 40s, some slightly elevated fire weather conditions may develop given highs well into the 60s. The aforementioned upper trough moves eastward late Thursday into Friday, pushing a surface front eastward. 06/12Z model guidance keeps this trough more positively tilted as it slides eastward, allowing moisture transport to focus along and ahead of the boundary as it slides east. Though there remain considerable differences in ensembles in the depth of the trough and if a stronger lobe of vorticity could track northeast. That said, ensembles are very bullish on precipitation with this front/system with 80% probabilities of >0.10" focused along and east of the James River valley. Though those probabilities drop quickly through higher QPF totals suggesting the progressive nature of the boundary and tilt of the system won't keep a focus in the area. There are also some signals for a deformation rain/snow band through central SD. Some elevated instability could also bring an isolated risk of thunder into Friday over portions of eastern Nebraska/Iowa.

SATURDAY-SUNDAY: Behind this trough and front there really is no cold air to move into the region. With the northern stream jet pushed well north of the border, broad westerlies will allow temperatures to remain well above normal in the 50s and 60s with breezy and dry conditions next weekend.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1048 PM CST Sun Mar 1 2026

Latest satellite imagery shows VFR stratus continuing to overspread most locations east of the James River late this evening. This stratus looks to remain at VFR levels through most of the night before dropping to MVFR thresholds by the end of the night. The VFR/MVFR stratus looks to persist through the day tomorrow while winds remain marginally breezy out of the south. Chances for rain will increase during the afternoon hours tomorrow and persist for the rest of the TAF period. Locations along I-90, including KFSD, have the highest chances currently to see light rain. While ceilings look to remain MVFR during this period of time, they could drop to IFR both during rainfall and the very end of the TAF period. Visibilities look to remain mainly VFR though could drop to MVFR levels in falling rain.

FSD WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None. IA...None. NE...None.