Marine Weather and Tide Forecast for St. Paul, MN

DISCUSSION
Issued at 256 AM CDT Sun Oct 13 2024

Overview...Early morning radar imagery captures a shield of rain pinwheeling across the Arrowhead, tied to a potent upper level-low.
The upper low and associated trough will dig southeast across the Upper Midwest today. Surface low pressure located in northern Minnesota will continue to deepen as strong curvature vorticity moves overhead. Cold air advection will continue to increase west of the surface low, ushering in much cooler air to close the weekend.

Wind... A cold front extending to the southwest of the surface low is quickly progressing east through Minnesota. North/northwesterly winds will increase following the passage of the front, owing to the expected tight pressure gradient west of the surface low. Sustained winds between 20-25 mph will pair with gusts of 35-40 mph for most of the daytime hours. Our expectation is that the overall wind scenario will fall short of advisory criteria, however forecast soundings indicate that isolated instantaneous gusts upwards of 45- 50 mph cannot be ruled out. Similar to the last few nights, we've opted to lean on the high end of blended guidance.

Shower Chances...The initial batch of rain referenced above is forecast to track southeast into northern Wisconsin over the coming hours, likely producing scattered showers through daybreak for locations north of I-94 in far eastern Minnesota and western Wisconsin. Following a post frontal lull, additional scattered showers will develop within the ongoing cyclonic flow regime.
QPF remains on the low side, with perhaps a few hundredths of an inch possible. Locations further east into western Wisconsin will have the best shot at a tenth or two of rain. Guidance swings a secondary shortwave trough into the Upper Midwest Monday, which will reinforce the cyclonic flow and pair with lingering moisture to produce another round of scattered showers across western Wisconsin.

Freeze Likely...The strong northwesterly flow will usher in below normal temperatures starting today and persisting through Wednesday morning. Afternoon highs top out in the low to mid 50s today through Tuesday, but it's the morning lows that will have folks needing to grab that extra layer or coat. Temperatures will dip into the 30s for Monday morning, with even colder temperatures (20s!) likely on Tuesday morning. Clear skies and light winds, along with high pressure in control will set the stage for another night in the upper 20s/low 30s heading into Wednesday. The growing season will effectively come to an end following three consecutive mornings with sub-freezing temperatures. STC observed a freeze on 10/4, however you have to go back to April for the last 32 degree or lower observation at MSP (4/20) and EAU (4/25).

Extended Forecast...Temperatures are forecast to rebound to mild values (70s) as an expansive upper level ridge builds over the central portion of the country. Mid-level warm air advection and southwesterly flow will increase out of the Great Plains ahead of the next trough moving into the western CONUS later this week. The approach of the trough will introduce the next best chance (and first in quite some time!) for widespread rain throughout the Upper Midwest. Global ensembles remain confident in precipitation potential, as ~90% of members across the grand ensemble (Euro/GFS/Canadian) produce measurable precipitation at MSP. Long term guidance (especially the EPS suite) suggest a change may be in store with additional chances for wet weather heading into the end of October.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/
Issued at 645 AM CDT Sun Oct 13 2024

A potent cold front will continue pushing east across across the region this morning, bringing a strong increase in northwesterly winds with and behind the front thru the day today, along with an increase in low-level moisture which will take the form of MVFR ceilings for much of the day. Speeds will increase to near 25G35kts for all sites, with gusts touching 40kts not out of the question for any given site. In addition, better forcing closer to the low, which will slide east- southeast over northern MN then northern WI, will possibly bring a few rain showers to the WI TAF sites at times today, but chances are a bit low to include at this point. Winds will then diminish and clouds will scatter out after sunset this evening as high pressure slowly arrives from the north, making for just high cirrus.

KMSP...Chances for precip are too low to be included so have maintained a dry TAF. Main issue will be the strong wind speeds lasting throughout the day. Gusts will very likely exceed 30kts, potentially approaching 40kts at times, despite the NW direction down the 30s.

/OUTLOOK FOR KMSP/ TUE...VFR. Wind N 5-10kts.
WED...VFR. Wind SW 10-15 kts.
THU...VFR. Wind S 15-20G25-35kts.

MPX WATCHES/WARNINGS/ADVISORIES
MN...None.
WI...None.