Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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272 FXUS63 KMPX 090543 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1243 AM CDT Thu May 9 2024 .KEY MESSAGES... - Scattered, pulse-y thunderstorms expected this afternoon and evening across southern Minnesota. Locally heavy rain and a few strong or severe storms are possible. - Periodic shower and thunderstorm chances will continue through early next week. - Temperatures will remain near or above normal. && .DISCUSSION... Issued at 252 PM CDT Wed May 8 2024 Our stagnant mid/upper level low pattern will slide east tonight, setting up a nearly horizontal, positively-tilted trough axis along the Minnesota/Iowa/SoDak border region. Soundings show an inverted-V setup, with cold air above a warm and dry boundary layer. Surface temps have already eclipsed 70F in much of southern Minnesota, supporting a broad area of 500 J/kg SBCAPE embedded with pockets of 1000+ J/kg along the MN/SoDak border. Steep low-level lapse rates will be enough to create a broad area of showers/storms, however lack of wind shear should prevent any longer-lived supercell convection. In other words, we are expected storms to form and dissipate quickly, leading to isolated hail and strong downdraft winds. Given the slow movement of the occluded low, some storms could tap into the effective SRH and form brief landspouts or weak non-supercell tornadoes. The main threat will shift to locally heavy rains overnight, with the highest totals expected south of the MN/IA border. Northeasterly flow behind the occluded front will advect in slightly cooler and drier air, leading to quiet weather tomorrow afternoon/night. An upper-level shortwave disturbance will then slide southeast through the Great Lakes region on Friday. Steeper lapse rates and patches of weak MUCAPE will likely lead to a broad area of scattered showers and thunderstorms across east-central Minnesota and western Wisconsin. The main forcing, and greatest QPF, looks to be trending slightly further east into Wisconsin per model (Euro and GFS) run-to-run change. The upper-level pattern will stay largely the same through early next week, with a cut-off low to the west and general troughiness to the east. Any small scale disturbances that ride down from Canada would bring similar chances for scattered showers and thunderstorms over the Upper Midwest. Temperatures will trend 5-10 degrees above normal, with some areas potentially seeing highs in the 80s Sunday- Tuesday. The best chance for that comes on Sunday, with nearly 50% of NBM members breaking the 80F mark across the southern half of Minnesota. The cut-off low over the western CONUS will attempt to progress eastward by mid-week, which would likely be the general timeframe of our next shot of active weather. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1239 AM CDT Thu May 9 2024 Very light rain will linger at MKT for another few hours, but otherwise quiet weather is expected through the period. Ceilings will lower overnight to around FL050, with lower MVFR ceilings possible this morning at RWF & MKT. These clouds will scatter out by late afternoon with clear skies expected tomorrow night. Winds will generally be northeasterly through the day with speeds around 10 kts and a few gusts up to 20 kts. Winds become light after sunset tomorrow with the direction gradually becoming southerly. KMSP...No additional concerns. /OUTLOOK FOR KMSP/ FRI PM...Chance MVFR/-TSRA. Wind NW 20G30 kts. SAT...VFR. Wind NW 10G20 kts. SUN...VFR. Wind W 15G25 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BED AVIATION...ETA