Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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299 FXUS63 KMPX 311143 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 643 AM CDT Fri May 31 2024 .KEY MESSAGES... - Today...Showers and thunderstorms will move across southern and eastern MN into western WI. Severe weather is not expected, but a few pockets of heavy rain are possible. - Saturday and Sunday...Most locations will be dry on Saturday as rain exits east. Another system will bring thunderstorms from the Dakotas into western MN on Sunday. A few storms could be severe across western and central MN, but storms should weaken as they move toward Wisconsin. - Tuesday/Night...Another system will bring widespread rain Tuesday and Tuesday night. Timing and placement are still uncertain, but the potential for severe storms bears watching. && .DISCUSSION... Issued at 318 AM CDT Fri May 31 2024 TODAY...Showers and thunderstorms were slow to progress eastward overnight, but have started to fill in across southern Minnesota as expected. These storms are along a weak boundary that will continue to sag southeast this morning, but then will stall out and shift north a bit as a warm front. Low level FGEN will lead to numerous showers and thunderstorms, and the steering winds aloft will parallel to the forcing. As a result, the main concern today is training thunderstorms, heavy rain, and potential for flooding. Overall this is a lower-end threat in the sense that the footprint of the heavy rain will be small, and the lack of a tropical airmass should limit the precipitation amounts. Current forecast has a pretty broad area of 1 to 2 inches with the northern extent along a line from Redwood Falls up through the Twin Cities and into Rice Lake WI. The southern extent is from north central Iowa up through Rochester MN and Eau Claire WI. Based on the synoptic set up and the HiRes output, a few locations within this area could see upwards of 3 to 4 inches. SATURDAY AND SUNDAY...No significant changes from the previous forecast. On Saturday showers and thunderstorms will be ending across western WI, so most locations should be dry, which is welcomed news if you have outdoor festivities planned. on Sunday the Day4 outlook area for severe weather transitioned to a slight risk across western MInnesota, with a marginal risk generally up to the WI/MN border. This event is driven by a low- amplitude shortwave trough which will lead to a favorable deep layer shear profile of southerly H925 winds, and westerly H500 winds. There should be adequate instability to support thunderstorms, and organized convection is expected to develop Sunday afternoon, and move eastward during the evening and overnight. Forecast soundings show capping in place across the warm sector, but this CAP should be just enough to limit early storm initiation and allow around 2000 J/kg of MLCAPE to develop. As of now, the main concerns appear to be hail mainly across western MN, transitioning to more of a wind threat as the storms congeal and move east. MONDAY THROUGH FRIDAY...Monday will be dry in the wake of the departing storm system. The dry period should be short-lived as another northern stream shortwave trough moves across the High Plains toward the Upper Midwest. In contrast to Sunday`s system, this wave is more amplified and takes on a negative tilt and should have stronger forcing for ascent. Another round of widespread convection is expected across the Upper Midwest. With the dynamics in place, the severe weather threat should hinge on the instability, which is highly uncertain this far out based on the timing of the system, so for now continued with the blended forecast guidance. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 635 AM CDT Fri May 31 2024 The chance for thunder is decreasing this morning, but should return later this afternoon. Showers will weaken this morning, but they should become more widespread with a few embedded thunderstorms later this afternoon into the evening. There is a high confidence of storms at KMKT and KEAU, but there is uncertainty at KRWF, KMSP, and KRNH. Overnight should see stratus/fog potential. KMSP... Did remove the thunder mention this morning at KMSP. The more vigorous updrafts should remain to the south. Storms will develop later this afternoon, and could impact KMSP, or could remain to the south. Did continue with a Prob30 for thunder for later today. Overnight could see some low stratus develop into Saturday morning. /OUTLOOK FOR KMSP/ SAT...VFR/MVFR. Wind SW 5-10kts. SUN...VFR, with MVFR/-TSRA likely late. Wind S 5-10kts. MON...MVFR/-TSRA early, then VFR. Wind SW to NW 10kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...JRB AVIATION...JRB