NWS Forecast Discussion
000 FXUS63 KMPX 240840 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 340 AM CDT Sun Sep 24 2023 .DISCUSSION...(Today through Saturday) Issued at 338 AM CDT Sun Sep 24 2023 KEY MESSAGES: - Scattered showers and storms possible this afternoon through Monday night. - Dry weather will return by mid-week with above normal temperatures through next weekend. Split flow aloft across NOAM this morning as the main jet is displaced off to the north. There is an upper low to our west that will dominate our short term pattern as it`s progression stalls overhead. The pattern is not exactly a rex block, but the impacts will be very similar as the flow slows down significantly over the next few days. At the surface an expansive high pressure is centered over Hudson Bay and Ontario that will become an important player later on in the forecast period. Our surface low is sitting over the ND/SD/MN border with it`s occluded front working through eastern MN into western WI. There is scattered showers with an occasional rumble of thunder mixed in here and there. We`ve managed to dodge a bullet as yesterday`s severe potential was not realized, partially due to the southern convection that tracked from Nebraska through Iowa, and partially due to a bit of missed timing among interacting features. What did play out is an area of locally heavy rainfall across portions of south central and eastern MN. Our office in Chanhassen ended up with a 24 hr total of 2.60", most of which fell between 00z and 06z. This "bullseye" ended up further east than guidance suggested last night, which was a concern due to the convective nature of the precipitation. Looking ahead, the ULL will provide a few additional chances of showers over the next few days. Drier air works in behind the occluded front and should allow us to stay dry for most of the day. Higher PoPs return across west central MN this afternoon as moisture wraps around the ULL. If you have outdoor plans it could be helpful to check the radar before you head out the door, but it will not be an all day rain event. Highs reach into the upper 60s and 70s with little to no sunshine to help warm us further. Tonight will cool back into the 50s for most locations and scattered showers continue to pivot around the ULL. Showers and thunderstorms will be possible through Tuesday AM across nearly our entire forecast area as continual lift will cause showers and storms to develop and wrap around the ULL. Thunderstorms will be most likely during the afternoon hours with no severe weather expected. Guidance shows that an additional 1" + of much needed rain could occur through Tuesday morning across portions of central MN into western WI. Rain chances finally taper off Tuesday as the ULL gradually drifts ESEward and exits the region. It`s important to note that guidance struggles to resolve cut off/closed lows in a blocking pattern so precip chances may lag further into the forecast period. Highs will be in the 60s and lower 70s Sunday thru Tuesday with lows in the 50s and lower 60s. Afterwards, the pattern turns drier with temperatures forecast to warm above normal for the end of week. Long range guidance favors a trough to dig into the western CONUS during the latter half of the week and amplify the pattern with a ridge building in over the Great Lakes and into eastern Canada. High temperatures in the upper 70s with a good chance for highs to hit 80 again next Friday and Saturday. NBM PoPs begin to creep up heading into next weekend but I`d expect the overall pattern to slow and those chances to be further delayed. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1200 AM CDT Sun Sep 24 2023 Thunder chances have diminished over the last hour or two. Scattered showers will continue through the night with steadier SHRA over the eastern sites (KMSP/KRNH/KEAU). MVFR cigs will trend toward IFR conditions tonight, but improvement back to MVFR and eventually VFR is expected later today. SE winds 10-15kts with gusts up to 25kts will gradually decreased through the morning. KMSP... Scattered showers continue tonight before diminishing later this morning. There is still some uncertainty to the additional SHRA chances today. We`ve added a prob30 to address the chance in the 21-24z time window, but guidance suggests that it could trend a bit slower/later. /OUTLOOK FOR KMSP/ Mon...Chc MVFR/-SHRA/-TSRA. Wind S 10 kts. Tue...VFR. Wind E 10 kts. Wed...VFR. Wind SE 10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BPH AVIATION...BPH
NWS MPX Office Area Forecast Discussion