Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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188 FXUS63 KFGF 300325 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1025 PM CDT Wed May 29 2024 .KEY MESSAGES... - Showers and thunderstorms are expected Thursday. - There is a low chance for severe thunderstorms Sunday during the afternoon and evening hours. && .UPDATE... Issued at 1014 PM CDT Wed May 29 2024 Wind have dropped off even faster than expected with decoupling under clear skies, however with strong LLJ just to the west sliding east through the evening/overnight we should see breezy conditions off and on. Upstream activity is struggling to make much eastward progress with the main instability/low level moisture axis/gradient well west of our CWA. Based on current trends though, we may see activity a little faster (around or after 06Z) in our far west and I made minor adjustments to reflect that. The main/organized period of rain and scattered thunderstorms is still on track for an arrival around or after 7am Thursday as the front and main mid/upper low moves into the region. This is supported by the latest/incoming 00Z HREF/CAM membership. Impacts will mainly be rainfall/embedded thunder. UPDATE Issued at 658 PM CDT Wed May 29 2024 Skies are clear, but ideal mixing has resulted in winds gusting a bit higher than originally forecast (35-38 mph) but as the sun starts to set we should see gusts decrease or drop for most locations (sustained winds will still remain breezy overnight). The general forecast is on track, so only adjustments were to near term trends. && .DISCUSSION... Issued at 348 PM CDT Wed May 29 2024 There is relatively high confidence regarding an active weather pattern unfolding over the next week. Rain chances increase on Thursday as an upper low ushers a trough across the Northern Plains. This trough is an extension of a larger upper low, which will serve as the source multiple thunderstorm axes through the next week. This first trough will have enough moisture to give us a 70 percent chance of 0.50 inch of rain across portions of the region, especially along the I-94 corridor in southeastern North Dakota and west central Minnesota. Look for mainly embedded thunderstorms with this first system. Heading into Friday and Saturday, a weak shortwave rotates around the H5 low, bringing additional showers and thunderstorms to the area. Minimal impact is expected from this shortwave, with less than a 20 percent chance for 0.10 inch of rain for the Devils Lake Basin. Sunday brings a stronger trough and associated theta-e gradient boundary. Slightly better forcing and moisture will be available with this wave, thus we could see a few strong storms develop during the afternoon and evening. Regarding SBCAPE, there is a 70 percent chance for greater than 1000 J/Kg and a 50 percent chance for 2000 J/Kg or more, especially in the far southern Red River Valley. Surface to 3km shear could range from 20 to 30 knots, with deep layer shear up to 40 knots. Although it`s still several days out, there is enough ensemble agreement to mention a low chance for severe thunderstorms Sunday afternoon and evening. The active pattern continues into next week, with thunderstorm chances entering the forecast again as we head into Tuesday. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 658 PM CDT Wed May 29 2024 VFR conditions are expected to prevail this evening into the overnight period across eastern ND and northwest MN. South- southeast winds remain gusty though, and as a 40-50kt low level jet moves across the region this evening/overnight low level wind shear should be expected. A cold front associated with a large low pressure system will bring increasing rain chances along with MVFR (low chance IFR) ceilings west to east Thursday morning through the early evening. Best chance for lighting activity/thunderstorms is in southeast ND midday Thursday, though they can`t be ruled out elsewhere. Behind the front winds shift to the southwest then west at KDVL and gradually decrease. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...DJR DISCUSSION...Lynch AVIATION...DJR