Sunrise 5:55 AM   Sunset 8:10 PM Moonrise 12:36 AM   Moonset 8:39 AM

  Print   HELP   Reset   Save   Recall

FXUS63 KMPX 290417 AFDMPX

Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1117 PM CDT Sun Apr 28 2024

KEY MESSAGES

- Showers & thunderstorms return on Tuesday, with a few strong to severe storms possible across southern Minnesota.

- Active pattern continues with additional chances for rain Thursday & next weekend.

- Temperatures will remain Spring-like through the work week.

DISCUSSION
Issued at 314 PM CDT Sun Apr 28 2024

It is a rather raw & soggy day across the Upper Mississippi Valley today. Widespread rain has spread across the region and will persist through this evening before tapering off overnight. Temperatures are more similar to mid-March, in the mid 40s, with sustained E/NE winds 10-15mph adding additional insult to injury to end April. The surface low located over NE Nebraska will track through southern Minnesota into northern Wisconsin before exiting through the northern Great Lakes. We'll see steady showers through the afternoon with an area of heavier rain setting up in the deformation axis across western Minnesota and eastern Dakotas. We're looking at 0.5 to 1.0" total rainfall by Monday morning with locally higher amounts possible across portions of western and central Minnesota. The cold & dry E/NE flow has limited any attempt to build instability into S MN & latest CAMs fail to bring the warm front into Minnesota or Wisconsin. This lines up with the SPC removing the Marginal risk of severe across S MN for this afternoon. There could be a few thunderstorms embedded in the precipitation that'll produce heavier rains & a few rumbles of thunder. Otherwise, we'll "dry out" overnight before the deformation zone pivots through Monday morning.

Monday will see shower chances return in the first half the of day, especially across W WI, before we actually dry out. Cool flow & overcast skies will limit our highs into the upper 40s and lower 50s for the second straight day. Tuesday will be a stark contrast to Monday. High temperatures will be in the 60s and lower 70s. A thermal ridge will move through during the day, allowing ample WAA to occur ahead of shortwave trough. That potent shortwave is forecast to dig into northern Plains and become negatively tilted by Tuesday afternoon. This will enhance flow and provide additional ascent across Upper Midwest Tuesday afternoon/evening, which will support shower and thunderstorm development across much of the area along and ahead of a sfc front. Timing is favorable, at peak diurnal heating, but our limiting factor will be the lack of CAPE (500 j/kg) & weak lapse rates (6.0-6.5 deg/km). So this isn't going to be a widespread severe but low CAPE/high(er) shear setup. Hires guidance brings a line of thunderstorms across Tuesday PM. A few strong to severe thunderstorms will be possible, and SPC's day 3 places us in a Marginal risk. What's more impressive is the trend in higher QPF associated with this wave. We've seen QPF more or less double since yesterday so another solid rain event is on tap for much of the area. We've also opted for 3 hourly PoP grids to better represent the passing line of thunderstorms on Tuesday.

Wednesday will be a brief return to drier, seasonal conditions with highs in the 60s and lower 70s. Guidance has doubled down on an another shortwave impacting the region Thursday into Friday. This was hinted at yesterday by a few ensemble members, but was far from the best signal. Fast forward a day and we're looking at solid chance for another widespread rain maker.
Temperatures cool into the 50s and 60s with likely PoPs now appearing in the NBM. As this system exits on Friday we'll see our active pattern continue as yet another system is possible this weekend before the pattern resets after next weekend. While temperatures have trended cooler for the first weekend of May appears to trending cooler, there is a signal for warmer temperatures to return for the second week of May.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
Issued at 1103 PM CDT Sun Apr 28 2024

Large rain shield continues to push off to the northeast, bringing in a fairly broad dry slot across the area to start so have initialized all sites as precip-free. From this point on, chances for additional precipitation through this TAF duration drop off with potentially only a few weak showers the rest of the overnight hours through late Monday morning. Ceilings will drop back to IFR for all sites by the early morning hours and remain there through most of the day Monday then slowly rise.
Winds will be a bit tricky to time, especially directions, as the low pressure circulation crosses southern MN, although speeds will be 10kts or less during these wind shifts.
Eventually, by late Monday afternoon, winds will become westerly with speeds upwards of 15G20kts.

KMSP...Ceilings to bounce between low-MVFR and IFR for the first few hours before settling on IFR shortly before daybreak. IFR ceilings expected to hold most of the day and into Monday evening before conditions improve Monday evening through Tuesday morning. Winds to undergo frequent shifts from E to S to W during the day Monday then become a bit breezy Monday evening.

/OUTLOOK FOR KMSP/ TUE...VFR through mid afternoon. MVFR or IFR with TSRA late aftn/evng. Wind SE 10-15G30 kts.
WED...VFR. Wind light/variable.
THU...MVFR/-SHRA likely. Wind ENE 10-15G25kts.

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

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

La Crosse, WI,