Marine Weather and Tide Forecast for St. Paul, MN

DISCUSSION
Issued at 138 PM CDT Mon May 12 2025

Largely warm, windy, and otherwise quiet across southern Minnesota and western Wisconsin this afternoon. High pressure continues to allow ample sunshine across pretty much the entire Upper Midwest. The increasing sun angle and strong southerly winds have again allowed some locations in western Minnesota to soar into the 90s, with Madison, MN reading 95 degrees as of 2PM. Today's conditions (highs in the 80s/90s, breezy southerly winds, no precip) will persist for a few more days before an upper-level trough finally breaks this pattern by Thursday.
This means at least 2 more days of dry and warm conditions. As a result, another critical fire weather day is expected tomorrow and a Fire Weather Watch was issued to reflect that. Today's Red Flag Warning remains in effect for essentially all of Minnesota and a good chunk of northwest Wisconsin through 8PM this evening. As the week goes on, relative humidity values will gradually increase via moisture advection, mitigating the fire concern slightly.

Another hazard resulting from the extended heat and dry conditions is a reduction in air quality. In coordination with Minnesota's Pollution Control Agency, an Air Quality Alert remains in effect through 9PM tonight for the western half of Minnesota (including the Twin Cities Metro). According to MN PCA, ground-level ozone is expected to be high during the afternoon hours on today across western and central Minnesota.
Mostly sunny skies, warm temperatures, and low humidity will create an environment favorable for two types of pollutants (Volatile Organic Compounds and Nitrogen Oxides) to react in the air to produce ground-level ozone. Ozone will be highest during the afternoon and early evening hours when sunshine is most abundant, and temperatures are highest. Ozone will be low in the morning, late evening, and overnight. Another alert is possible on Tuesday afternoon as sunny skies and heat persist.

Wednesday evening, an anomalously deep low-pressure system heads our way. The ECMWF Mean Sea Level Pressure is forecasting a sub-990 hPa low, which places it in the minimum bin for model climatology. Additionally, forecast precipitable water values increase to 1-1.5". This would be a very warm welcome to the region as a widespread rain is due. The severe weather potential is limited to far SE MN and SW WI, mostly outside of our forecast area. Thunderstorms are still possible through the day on Thursday, but the threat for severe weather remains low.
A cold front will push through the region by the end of the week. High temperatures Friday-Sunday will only run from the upper 50s to mid 60s. Low temperatures will plunge all the way to the mid 30s to mid 40s.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
Issued at 641 PM CDT Mon May 12 2025

Another period of VFR. Breezy southerly gusts are expected to diminish at all sites around 01-2z becoming southeasterly this evening. Diurnal wind speed increases can be expected after 15z Tuesday with 20-25kts mainly for our western most sites. Some low-level cu is possible tomorrow afternoon but should not cause any impacts to VFR flight categories.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/ WED...VFR. Wind SE 5-10G18kts.
THU.. MVFR/RA likely, chc IFR/-TSRA. Wind SE to SW 10-15G20-25kts.
FRI.. MVFR/RA likely. Wind W to NW 10-15G20-25kts.

MPX WATCHES/WARNINGS/ADVISORIES
MN...Red Flag Warning until 9 PM CDT this evening for Anoka-Benton- Blue Earth-Brown-Carver-Chippewa-Chisago-Dakota-Douglas- Faribault-Freeborn-Goodhue-Hennepin-Isanti-Kanabec- Kandiyohi-Lac Qui Parle-Le Sueur-Martin-McLeod-Meeker- Mille Lacs-Morrison-Nicollet-Pope-Ramsey-Redwood-Renville- Rice-Scott-Sherburne-Sibley-Stearns-Steele-Stevens-Swift- Todd-Waseca-Washington-Watonwan-Wright-Yellow Medicine.
Fire Weather Watch from Tuesday morning through Tuesday evening for Benton-Brown-Chippewa-Douglas-Kanabec- Kandiyohi-Lac Qui Parle-McLeod-Meeker-Mille Lacs-Morrison- Nicollet-Pope-Redwood-Renville-Sherburne-Sibley-Stearns- Stevens-Swift-Todd-Watonwan-Wright-Yellow Medicine.
WI...Red Flag Warning until 9 PM CDT this evening for Barron-Dunn- Pierce-Polk-Rusk-St. Croix.