Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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488 FXUS63 KFGF 071942 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 242 PM CDT Tue May 7 2024 .KEY MESSAGES... - A line of weak thunderstorms will continue north this afternoon with the potential for gusty winds to 50 mph and small hail. - Scattered rain chances return this weekend. && .DISCUSSION... Issued at 242 PM CDT Tue May 7 2024 Storms continue to fire along the northward moving occluded front and currently span from the Valley City to Fargo corridor and southeast to Fergus Falls. These will continue to propagate north/northwest as the front wraps around the upper low to the southwest centered over the central ND/SD border. MLCAPE of 400-800 J/kg per latest RAP analysis overlaid upon the ample boundary vorticity have created sporadic weak mid-level (850 MB) mesos with this short sub-6km deep convection. Should continue to see a small hail and gusty wind threat through the afternoon with these as they move north though the landspout/weak tornado threat seems to be low as cells struggle to remain discrete and rain into each others updrafts. Clearing behind the main line may yield enough instability to see a few more storms form behind this initial line but remain weaker with more mid level dry air to contend with. Gusty synoptic 30+ mph winds will begin to drop off after sunset as we develop the evening inversion leaving a pleasant night. A breakdown of the upper low over the next 2 days will see continued cloud cover with periodic shower chances through Wednesday as the low meanders south with weak upper flow to move it along. Another 0.10 to 0.25" remains possible before this round of rain ends primarily north of HWY 200. A drier period begins after this round moves out with eastern ridging forming atop a developing cutoff low in desert SW arching into the northern plains by late week. Northerly flow along the eastern edge of this ridging will see shortwaves rounding the ridging with our next potential rain maker Friday though not looking at a soaker with this quick moving clipper type system. Low level ridging will see relative humidity dropping below 40% each day Thursday- Sunday for at least a portion of the forecast area. The strongest surface pressure gradient doesnt move over head until Friday/Saturday quelling concerns of fire weather though remains something to monitor. Chances for precip look to then stem from ridge riding waves late weekend into early next week Though uncertainty remains high with timing and amounts. Highs through the period as ridging dominates will be in the 60s to 70s with average highs in the mid 60s for the second week of May. Lows in the 40s to low 50s each night for the week should provide near term relief from any late season frost threat for gardeners who have already started spring planting or are looking to start. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1244 PM CDT Tue May 7 2024 CIGS lifting to VFR across most sites this afternoon with clearing area moving in, however CU/SHRA development may keep some MVFR CIGS through the afternoon before drier air moves in with the upper low in place and CIGS become VFR overnight. Winds to be more southeasterly to southerly through the period with gustiness continuing this afternoon, and should start to see diminishment in the gustiness overnight. May still see some lower CIGS in the far north/east build back in late tonight toward sunrise as the main upper level system wobbles around just to the west of the area. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ DISCUSSION...TT AVIATION...MJB