Area Forecast Discussion

KEY MESSAGES

- Critical Fire Weather Conditions expected over much of central through southwestern MN the rest of today.

- Temperatures to remain above normal through Thursday, including highs in the 80s for much of southern MN on Wednesday.

- Showers and thunderstorms return on Thursday, then dry and cool conditions expected for the upcoming weekend.

DISCUSSION

Issued at 205 PM CDT Mon Apr 20 2026

It's a fairly classic Spring elevated fire danger day across the upper MS Valley. High pressure is continuing to slide east across the Great Lakes, putting us in a region of enhanced southerly flow on the west side of the high. Given this high pressure originated in northwest Canada, the airmass today is quite dry, as evidenced by RH values that had largely fallen below 30% by noon. These very low RH values will continue on Tuesday as well. However, Tuesday will feature light winds and therefore a reduced fire danger. Going into Wednesday, we'll see low pressure deepen to over the western Plains as a large h5 wave moves across the Rockies. This deepening low to our west will allow for southerly winds to pick up in strength again. In fact, winds Wednesday look to be 5-10mph stronger than today. The main difference between today and Wednesday is those southerly winds will also be ushering much higher dewpoints. However, in the Spring before we are fully greened up, we often see the NBM underdo the power of mixing (see today...). The NBM currently brings dewpoints up to around 50 on Wednesday, but with temperatures surging well into the 80s (and possibly even 90 in west central MN), it won't take much of a drop in the forecast dewpoints to again send RHs crashing below 25%. Right now, RHs largely remain in the lower 30s on Wednesday, but if we're overdoing the amount of low level moisture we get up here, then we could have significant fire weather concerns again on Wednesday given the winds that are expected.

Our best chance for precipitation this period continues to come Thursday into Thursday night. A surface low is forecast to become occluded over NoDak on Thursday, with it wrapping up and drifting north or even northwest across Manitoba Thursday night. This low will send a cold front surging across MN and a dry slot across SoDak on Thursday. We continue to see differences in how far east this front will be when deep convection initiates along it, though guidance continues to favor eastern MN and western WI for having the best precipitation chances. In fact, western MN could see another day of elevated fire weather issues depending on how the dry slot over SoDak evolves. On the other side of the cold front, showers and thunderstorms will eventually develop during the afternoon along/ahead of the front. The main question for whether or not that convection will be severe is the degree of instability we're able to build this far north. However, CSU GEFS based machine learning severe probabilities support a severe risk existing anywhere ahead of the cold front, so this continues to be a period to keep an eye on. From the rainfall perspective, this will be convection, so there will be some pockets of heavier rain, but in general, given the progressive nature of the forcing, rainfall for most should amount to less than a half inch.

For Friday into next week, a long wave trough will setup across the center of the continent. This will mean we're back to seasonably cool highs in the 50s. The weekend looks dry with high pressure overhead, but early next week, we're starting to see more models come on board with a shortwave rotating around the Canadian H5 low, bringing a renewed chance for showers to start the final week of April.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 541 PM CDT Mon Apr 20 2026

VFR conditions expected the entire period with scattered to broken high clouds giving away to clear skies after midnight tonight. Southerly winds will gust to 20-25 knots for a couple of hours before slowing to under 10 knots late this evening. Winds will slow to near or under 5 knots during early Tuesday morning while turning north-northeasterly into late morning. Sustained values will range from 5-10 knots Tuesday afternoon.

KMSP...Southerly winds will gust to near 20 knots for a couple more hours this evening. Some southwesterly LLWS is possible before 06z tonight but most of the LLWS will be off to the east and at or below 35 knots. A 2-3 hour period of northeasterly winds near 5 knots is possible from 12-15z Tuesday. Northerly winds near 8 knots prevail after 15z but winds turn more easterly again during Tuesday evening.

/OUTLOOK FOR KMSP/ WED...VFR. Wind SE 10-15G25 kts. THU...MVFR/-RA likely, mainly PM. Wind S 10-15G25 kts. FRI...VFR. Wind. W 10-15G25kts.

MPX WATCHES / WARNINGS / ADVISORIES

MN...Red Flag Warning until 8 PM CDT this evening for Benton-Blue Earth-Brown-Chippewa-Douglas-Faribault-Isanti-Kanabec- Kandiyohi-Lac Qui Parle-Martin-McLeod-Meeker-Mille Lacs- Morrison-Nicollet-Pope-Redwood-Renville-Sherburne-Sibley- Stearns-Stevens-Swift-Todd-Watonwan-Wright-Yellow Medicine. WI...None.