Area Forecast Discussion

KEY MESSAGES

- Light to moderate rain showers slowly spread northward Friday afternoon, lasting through the day on Saturday before decaying Saturday evening.

- A more prolonged stretch of wet weather arrives during the day on Monday and lasts through at least the middle of the week.

- After a brief cool down to end this week, above normal temperatures return for the weekend and into the middle of next week, then slide back towards average later in the week.

DISCUSSION

Issued at 1254 PM CDT Thu Oct 29 2026

Friday - Saturday: Rainfall Details

A broad corridor of weak mid-level isentropic ascent and theta-e advection works into the region starting Friday afternoon, lifting north and waning through the afternoon on Saturday. This forcing should spawn a ribbon of scattered rain showers that likewise lifts northward in this 24-hour window. Rainfall amounts don't look to be exceedingly high (20-30% chance of seeing amounts over 1/4"), but they could still be enough to put a damper on Halloween activities. Extended HRRR/REFS runs are not overly excited in the coverage of these showers through Friday night--a bit of good news for those who have early Halloween plans. Moving into Saturday, there is higher confidence (60-70%) in there being some light shower activity during the daytime hours, but the all important Halloween rainfall forecast remains more nebulous with the decaying nature of the showers (PoPs in the 10-20% range). Best guess is that there will still be lingering showers come sunset, but most areas will stay on the drier side, especially west of the Mississippi River.

Next Week: Prolonged Stretch of Rainfall

What is shaping up to be one of our more dynamic systems thus far this fall remains on track to occur early next week, but large scale details are still coming into focus that will play a major role in the local forecast. While many solutions yesterday were focusing on the northern stream energy phasing with the southern trough early in the week, the medium range deterministic and ensemble solutions are coming in line with their AI counterparts and now favoring these two airstreams/troughs to remain out of phase, resulting in the formation of double barrel/disjointed low structure along the Front Range on Monday night. This pushes the corridor of heaviest rainfall to the west of the region and results in an overall faster progression of the system Wednesday onward.

No matter how you slice the forecast it still looks like a wet and cloudy few days starting Monday and going through Wednesday, it's mainly a question of whether we see a quarter to half an inch of rainfall over those few days (a near certainty in the ensemble solutions) versus some of the higher outliers that push 2-3 inches over the 3 days (10% chance). While seemingly unlikely at this stage, if the northern low trends stronger over the coming days, a risk for stronger storms could creep into our area on Tuesday afternoon. Not even the AI guidance is showing this possibility at this time, but seeing a warm sector of 60+ dewpoints wrapping around this cyclone in Minnesota should get one's attention for early November!

Temperatures Trends into Next Week:

Temperatures fall back closer to seasonal norms (highs in the mid-50s, lows in the 30s) for today and Friday in the wake of last night's cold front. However, warm air advection kicks in ahead of next week's system by Sunday and temperatures should once again trend 5-10 degrees above normal through Tuesday or Wednesday before colder air arrives for the end of the week. Given the influx of precipitation and uncertainties in the synoptic structure of next week's system, there is naturally higher than normal uncertainty in how temperatures will pan out for Tuesday through Thursday. It does look more likely that lows will be on the warmer side (forecast NBM lows Monday night are at or above our average highs for this time of year!) until the cold front arrives, though when that front comes through varies by 24-36 hours at this range.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1254 PM CDT Thu Oct 29 2026

Mainly VFR conditions are forecast for the TAF period with a low (<10%) chance of of patchy overnight fog in some lower-lying locales east of the Mississippi River. Northwesterly winds of 5-10kts this afternoon become light and variable this evening, increasing at 5-10kts from the east on Friday.

ARX WATCHES / WARNINGS / ADVISORIES

WI...None. MN...None. IA...None.