Porter, MN Weather

This Hazardous Weather Outlook is for portions of central and southern Minnesota, and west central Wisconsin.

Day one

Today and Tonight.

No hazardous weather is expected at this time.

Days two through seven

Saturday through Thursday.

No hazardous weather is expected at this time.

Spotter information statement

SKYWARN spotter activation will not be needed.

Key messages

- Dry today with a few hit and miss showers for Saturday, but the weather shouldn't dampen any Halloween plans you have too much.

- A slow moving low with a minimum pressure in the 990s will move across MN Monday into Tuesday. This system will have near record high PWATs for November, with a widespread soaking rain expected.

Discussion

Issued at 337 AM CDT Fri Oct 30 2026

Today through the weekend: The evolution of the weather pattern this weekend will be interesting. There will be troughs digging in the Pac NW and New England. The atmospheric response to these coastal troughs will be building heights and ridging across the north central CONUS into the Canadian Prairie provinces. Getting thrown into this ridge mix is the upper trough currently seen on water vapor imagery coming out of Mexico into western TX and New Mexico. As we go through the weekend, this upper energy to our southwest will drift northeast into our ridge. What won't be lacking is moisture, with PWATs expected to build to over 200% of normal. What is lacking is forcing with the building heights locally. The net result is models (CAMs, deterministic, and machine learning) show smatterings of light QPF moving north across the area Friday night through Saturday. Given the scattered nature of activity we're seeing with the CAMs, we did reduce PoPs from the NBM to hold PoPs down in the chance category. What this upper energy coming up from the south will do is provide us with a mild and cloudy weekend. For the 35th year in a row, we will not repeat the Halloween of 1991, but you may encounter some damp conditions.

Monday and Tuesday: This is the portion of the forecast that looks intriguing. We will see the west coast trough from this weekend move out across the Plains. At the surface, we'll have a slow moving low with MSLP values in the 990s move across the center of the country. Guidance has continued to drift north toward where the AIFS has been the last few days with a surface low working across MN Monday into Tuesday. This low will be a powerhouse when it comes to rainfall potential. PWATs this weekend that will be 200-250% of normal will surge to near 400% of normal early next week, or over 4.5 standard deviations above normal. There will be two phases of forcing with this system. Monday will feature strong isentropic lift, with a broad band of moderate rain expected to move north across the area with this isentropic lift. Monday night into Tuesday, we transition to deformation precipitation within the cold conveyer and warm sector showers (and probably a few storms) ahead of the cold front. Locations that end up north of the surface low track will double dip on the isentropic and deformation rainfall. Much of the guidance out there has a band of over 2" QPF north of where that model tracks the surface low. In fact, when looking at the 00z EPS members at MSP, the 90th percentile for QPF is over 3", so this lends some confidence in a high end rainfall event for November standards occurring with this system early next week. In fact, the EPS has a 70-90% chance of QPF exceeding 1" across the entire MPX area. From a climatology perspective, MSP averages 1.61" of liquid for the entire month of November. The greatest calendar day liquid precipitation on record in the Twin Cities for the month of November was 2.52" on November 11, 1940, which of course was the great Armistice Day Blizzard. You may have noticed we never mentioned anything other than rain with this system next week and that's because there's absolutely no cold air for this low to tap into, so it's all rain and a storm that will easily fall into the "waste of a good winter storm" category.

Finally something else to keep any eye on with this system will be how the warm sector evolves. With h85 winds forecast to be up over 50 kts, we will have strongly curved hodographs in the warm sector. If we can somehow manage to get some instability up here (which isn't an outlandish proposition with dewpoints likely to surge into the lower 60s), then we'll have a pretty classic low CAPE/high shear severe weather setup. Right now, it looks cloudy with saturated profiles that greatly limit our instability potential, but given the degree of shear we'll have, we'll have to keep a close eye on the instability potential.

Wednesday and beyond: After Tuesday, there's a lot of spread with how long we'll remain in moist cyclonic flow behind the early week low. In general, we like the idea of the NBM with PoPs slowly decreasing Wednesday into Thursday as this system slowly pushes east across the Great Lakes. The end of this forecast also looks to be the beginning of a rather blah period of weather as split flow develops across North America, with a weak northern stream well to our north in northern Canada and a dominate southern stream down near the Gulf coast (a rather classic El Nino weather pattern). This will keep storm systems away from us and leave us with a mild airmass in place. In fact, it looks unlikely for MSP to see sub freezing temperatures into the middle of November. We may end up making a run at November 18, 2016 for the latest first freeze on record for the Twin Cities.

Aviation

Issued at 1206 PM CDT Fri Oct 30 2026

VFR conditions continue, though ceilings are already beginning to lower across northern Iowa and southern Minnesota. These MVFR cigs will push north through the period, covering much of the region by tomorrow morning. As this system moves through, light, scattered showers are expected. The primary impact will be with lowering cigs, likely dropping to IFR during the mid- late morning for areas that see rain. Showers likely become isolated by Saturday evening, though ceilings will remain MVFR/IFR. Winds will remain light, generally below 10 kts, out of the E/SE.

KMSP: High clouds have begun to clear out this afternoon, however another deck of mid-high level clouds are approaching from the south already. Expect ceilings to lower through the period, eventually dropping to MVFR between 07-10z. On and off rain showers are expected tomorrow morning, with ceilings dropping to IFR at times as the heavier rain moves through. Visibility is expected to stay MVFR or better.

/OUTLOOK FOR KMSP/ SUN: VFR. Wind SE 5-10 kts. MON: MVFR/IFR. SHRA. Wind SE 10-15G30 kts. TUE: MVFR. -SHRA. Wind SE to NW 10-15G20 kts.

Watches, warnings and advisories

MN: None. WI: None.