textproduct: Sioux Falls

KEY MESSAGES

- QUIET AND MILD: Dry conditions and above normal temperatures continue early this week with highs in the 50s and 60s.

- MINIMAL RAIN MID-WEEK: The only precipitation chances in the next 7 days will occur late Tuesday night into Wednesday, but any rain will be very light and unimpactful.

- COLDER AIR AHEAD: A strong front drops temperatures significantly Thursday and Friday, though temperatures will gradually warm above normal by next weekend.

DISCUSSION

Issued at 1202 PM CST Sun Nov 8 2026

THIS AFTERNOON: A beautiful Fall day continues across the region as we're seeing plenty of sunshine, temperatures above normal, and generally light winds. In fact, the latest NBM continues to be a few degrees too cool for highs, so have adjusted upwards. This trend likely continues Monday as well.

TONIGHT: Weak southwesterly surface winds will develop later this evening and continue overnight. While broad warm advection continues above the ground, there may be some potential for valley/river fog into Monday morning. The general increase in mid- upr clouds could temper this potential somewhat.

MONDAY-TUESDAY: Extremely quiet weather continues early this week. A frontal boundary will swing southeast across the Tri-State area early Monday morning, turning a light southwesterly wind towards the west-northwest in the afternoon. Not a ton of cold air behind this boundary, so anticipating highs rising into the 60s in most locations. High pressure passing through the Plains Monday night shifts southeast of the area by Tuesday. Additionally sfc cyclogenesis over the Western High Plains will aid in inducing a southwesterly boundary layer flow on Tuesday. Temperatures will again rise into the upper 50s in most areas. One area to watch in this timeframe would be a repeated risk for valley fog Tuesday morning as winds may be very light and the low-lvl ridge remains west of the CWA. HRRR/RRFS both indicate increased potential for lowered visibilities.

TUESDAY NIGHT-WEDNESDAY: The only PoPs in the 7 day forecast are focused in the late Tuesday night and Wednesday timeframe. A progressive open shortwave leaves the Pacific Northwest and reaches the Plains Tuesday night. This moisture starved wave could lead to a few sprinkles into Wednesday morning. A deeper upper trough centered over Hudson Bay will allow a second shortwave to pivot southward out of central Canada and into the Plains on Wednesday. Again not a ton of moisture with this system through the column, but perhaps a brief window early Wednesday where sprinkles to a very light rain shower will be possible. Ensemble probabilities remain low, with measurable rain chances between 20-40%, and probabilities of >0.10" near zero. NBM probabilities are likely too low, which is understandable given spread in models. Either way, not a highly impactful system.

THURSDAY-SUNDAY: Arctic high pressure arrives into the Plains for Thursday. This 1033 mb high pushes a shallow but meaningful drop in temperatures southwards, with highs on Thursday favored to be in the lower 40s Thursday and Friday. Some of the coldest air of the fall season may arrive Friday morning with lows potentially in the lower to middle 20s. 25/75th percentile data from the LREF suggests a wider range of possibilities (>10 degree spread) west of the James River which is the result of uncertain low-lvl warm advection return.

Mid-lvl heights grow through next weekend, with strong indications of a continued dry forecast through Sunday. Temperatures will also begin to rise after the arctic high passes likely at or above normal. A 15 degree spread in the 25/75th high temperature forecast through the weekend may be the result of some uncertainty on the eastward progression of the mid-lvl ridge and continued influence of cooler SE surface flow. Regardless, near to above normal temperatures are favored.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1052 AM CST Sun Nov 8 2026

VFR conditions with a light southerly wind will persist into the overnight hours. As winds weaken, a low probability develops for river/valley fog by daybreak. However a broad increase in mid-upper clouds may temper this risk. A frontal boundary will sweep from west to east Monday morning turning southerly winds to west northwest.

FSD WATCHES/WARNINGS/ADVISORIES

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