Marine Weather and Tide Forecast for Spring Park, MN

DISCUSSION
Issued at 347 AM CDT Tue May 13 2025

Surface analysis early this morning depicts the still-stalled wavy stationary front north of the international border, attendant from one surface low over southern Saskatchewan province, and a trailing cold front extending SW over the Rockies into SoCal with multiple small lows along it. Aloft, the pattern remains of solid southwestern flow over the central CONUS with the deep lows over the southeastern CONUS and PacNW.

The main differences between today from yesterday will be a slight increase in moisture advection, lesser winds over much of the southern-eastern portions of the WFO MPX coverage area, and an increase in cloud cover from the southeast as that deep low migrates northward into the Ohio Valley. Western MN still features the breeziest winds being in open country and the tightest pressure gradient across our CWA, along with the driest air as RHs out west again drop to the teens. However, for today, the difference is that the northward moving SE CONUS low will advect in greater moisture into central-eastern portions of our CWA while winds drop off. Thus, Red Flag conditions are expected to be realized for the western half of our CWA, not the greater expanse seen yesterday.

Also of note is that the continued warm/dry conditions will promote degraded air quality due to ground-level ozone. MPCA has continued its Orange Air Quality Alert for all of our MN counties except 2 (Goodhue & Chisago) thru 9pm tonight.

A few deterministic models do try to develop isolated RA/TSRA over far SE MN into SW WI, owing to the northward push of the aforementioned low over the SE CONUS. However, the overall deep dry layer remains in place and this is reflected in CAMs which keep our CWA dry through the day. A few returns may drift into western WI this afternoon but virga is more the order of the day rather than bonafide precipitation reaching the surface. As such, have kept today dry.

The transition day to a more active pattern later in the week is Wednesday. The cold front over the western CONUS gains impetus to shift eastward as the now-open trough aloft out west slides eastward, coinciding with the eastern deep low moving to the Great Lakes-Mid Atlantic states and opening up. This is highly evidenced by the dewpoint forecast. Yesterday, Td's dropped to the 30s. Today, Td's range from the upper 30s in western MN to the lower 50s in western WI. Wednesday, Td's will range through the 50s west-to-east across our CWA High temperatures will generally remain the same from today to tomorrow, ranging from the lower 80s in western WI to the lower 90s in western MN.
Thus, heat index values will be a touch higher on Wednesday but only run within a degree or two of the actual temperature. Thus, this will essentially increase the instability levels, particularly in western MN, which happens to be in closest proximity to the incoming cold front. Thus, clouds will increase during the day Wednesday and precipitation chances significantly increase Wednesday night as the frontal makes inroads to western MN. The concern turns to convection as the WFO MPX coverage area becomes partially placed within the warm sector of the advancing low pressure center, dropping potentially to ~990mb, arriving from the Dakotas in advance of the positively-tilted trough aloft. While the bulk of any convective activity will occur during the day Wednesday over the Dakotas within a more unstable environment with better frontal dynamics, there is a chance that an additional round of convection Wednesday night may producing a few stronger storms along the advancing cold front. Even without the stronger storms, rainfall is expected to be fairly widespread late Wednesday night into early Thursday morning.

Precipitation will continue for much of the day on Thursday, particularly in the afternoon and evening as the surface system and trough aloft slide east. Another surge of moisture northward into the system along with regenerative dynamics, including an 850-700mb jet around 60kts and dewpoints returning to the low-mid 60s, will produce MLCAPEs to nearly 2500 j/kg during the afternoon-evening hours. Though it may take much of the day to get there, more organized convection looks to develop over mainly eastern MN into western WI late Thursday. Exactly where the best potential for severe develops still has some uncertainty, but SPC has been highlighting the Upper Midwest to Ohio Valley for several days so this does necessitate giving it due attention to see how it evolves.

As previously alluded to, QPFs could be fairly plentiful for some locations Wednesday night through Thursday night given the dynamics and moisture content (i.e. PWATs still 1.00-1.50")
at play. Obviously, this precipitation will be highly welcome given the persistent heat and dryness our area has experienced recently. This system looks to have a one-two punch of cold fronts sweeping through the area, one late Thursday followed by another on Friday. These fronts will be followed by a significant surge of colder air into the region starting the end of this week and continuing into next week. High temperatures Friday-Sunday will only run from the upper 50s to mid 60s(!)
while low temperatures plunge all the way to the mid 30s to mid 40s(!!), and these temperatures look to remain in these ranges through at least the middle of next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
Issued at 1227 PM CDT Tue May 13 2025

Southeasterly winds will remain around 10 to 12 knots with afternoon gusts between 15-25 knots. The strongest wind gusts are forecast across western MN (AXN/RWF). Winds decrease this evening before increasing back to 10 knots by Thursday mid- morning. VFR throughout but the gradual increase of low level moisture from our southeast has allowed scattered diurnal Cu to develop between 5-8kft. These will dissipate after sunset.

KMSP...No additional concerns at this time.

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

MPX WATCHES/WARNINGS/ADVISORIES
MN...Red Flag Warning until 9 PM CDT this evening for Benton-Blue Earth-Brown-Chippewa-Douglas-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.