textproduct: Sioux Falls

KEY MESSAGES

- Near normal temperatures expected this weekend. Outside of Saturday morning sprinkles, no rain is anticipated.

- Temperatures begin to warm through the upcoming work week, and by the end of the week may be approaching the lower to middle 80s with outside chances of 90 by the weekend.

- Rain chances for the week ahead will be focused on Monday night and again Thursday, though amounts will stay low. Severe weather risks also remain low.

UPDATE

Issued at 848 PM CDT Fri May 8 2026

Now that we're starting to lose our diurnal mixing, any elevated fire concerns are waning this evening. Similar to last night, should see relative humidity (RH) values gradually recover overnight as temperatures fall into the mid to upper 40s. Otherwise, we're still on track for a few additional sprinkles to light showers as a cold front tracks through the area to start the day on Saturday. While mainly light accumulations are expected, some of the 00z high- resolution guidance is starting to show more coverage than originally anticipated so slightly tweaked our POPs to get more coverage in there especially north of I-90. Nonetheless, should see most of this developing activity exit our region by midday. Lastly, another round of drier conditions is expected behind the cold front. As a result, can't rule out some locally elevated fire concerns in the afternoon/evening as northerly winds strengthen.

DISCUSSION

Issued at 1248 PM CDT Fri May 8 2026

THIS AFTERNOON: A warm, dry, and windy afternoon continues throughout the forecast area this afternoon. As temperatures rise into the 70s, we'll continue to see RH values fall towards the 20% range. As we reach peak mixing, gusts should begin to top in the 20 to 30 mph range in the Tri-State area. While RFW criteria may be met for a couple hours this afternoon, recent greenup should prevent widespread extreme fire behavior. Soundings continue to show the very low probability of isolated showers popping up after 21Z in areas along but mostly southeast of I-90. Severe storms not expected, but brief 30-40 mph wind gust may be possible.

TONIGHT: Winds settle down this evening, but will remain southwest through the night. This results in warmer overnight low temperatures in most locations.

SATURDAY: By daybreak Saturday, confidence remains high that a weak cold front will settle southward through the area. By 12Z this front may be just north of I-90 bringing with it a change to a northerly surface wind, but also a low probability for high based sprinkles/showers/virga. Once this front clears the area, temperatures slowly warm back to the mid-60s, with breezy northerly winds into the early evening.

SUNDAY: Temperatures remain cool on Sunday under the influence of Canadian high pressure. With a light north wind continuing, high temperatures stay in the middle to upper 60s.

MONDAY-WEDNESDAY: We'll begin to see a gradual rise in temperatures as mid-lvl heights rise through the Plains. Despite a breezy southeast wind Monday afternoon that could lead to elevated fire danger, high temperatures return to the 70s in most locations with 20-30% probabilities of 80+ degree temperatures in south central SD. A frontal boundary swings eastward Monday evening and overnight. MLCAPE profiles suggest some potential for 500-1000 J/KG through central SODAK, but moisture itself remains very limited and there is also a bit of capping in place. This should limit the overall developmental potential of any activity that tries to develop as the front moves east overnight. Temperatures cool slightly on Tuesday as low-lvl flow shifts to the northwest. The latest NBM suggests potential for 30 to 40 mph afternoon wind gusts, which is a signal within the EC/CMC deterministic and ensemble guidance. The GFS/GEFS is quite a bit lower, but if these winds do develop, then fire danger may be quite elevated through the region. Overall probabilities of exceeding 30 MPH are greater than 80%, with potential of 40+ mph around 10-20%. Winds again turn to the south on Wednesday, keeping high temperatures in the middle to upper 70s.

THURSDAY-SATURDAY: While quite a bit of uncertainty remains in the specifics for the end of the week, overall trends in ensemble data suggest a warming trend continues into next weekend. Mid-lvl heights continue to rise through the end of the week, pushing 850mb temperatures into the 20C range by Friday. The presence of several weak mid-lvl perturbations adds some uncertainty to the forecast in regards to thunderstorm and cloud potential. This is partially why the NBM 25/75th percentile temperature spread climb to nearly 10-15 degrees by Thursday and Friday. However, the broad synoptic pattern does seem to favor more convection risks (perhaps even stronger convection) within the region by next weekend.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1035 PM CDT Fri May 8 2026

Mainly VFR conditions will continue this TAF period. Taking a look at satellite imagery, mostly clear conditions continue this evening. However, should see stratus and pockets of sprinkles to light showers approach from the north with a cold front. With this in mind, decided to go prevailing -SHRA for all TAF sites for at least a portion of the TAF period. Nonetheless, any accumulations should be minimal. Lastly, light southwesterly winds will become more northerly behind the cold front with breezier conditions expected during the afternoon hours.

FSD WATCHES/WARNINGS/ADVISORIES

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