Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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534 FXUS63 KFGF 150413 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1113 PM CDT Fri Jun 14 2024 .KEY MESSAGES... - Multiple rounds of showers and thunderstorms are forecast tonight through Tuesday. - Saturday through Tuesday, there is potential for multiple rounds of strong to severe thunderstorms, in addition to potential flooding impacts from excessive rainfall. && .UPDATE... Issued at 1112 PM CDT Fri Jun 14 2024 Rain continues to overspread the region this evening, with west central MN seeing little to no precipitation. Some embedded thunder and lightning will be possible for the Devils Lake Basin through the early morning. This is where the instability has remained higher this evening. Rain will continue to spread eastward overnight, with lingering showers by mid morning for the valley points eastward. UPDATE Issued at 709 PM CDT Fri Jun 14 2024 Watching the showers and embedded thunderstorms in north central North Dakota move slowly eastward into the Devils Lake Basin and Sheyenne River Valley this evening. They will continue to shift into the valley overnight and into NW MN in the early morning hours tomorrow. Otherwise, temperatures are in the 70s to lower 80s this evening. && .DISCUSSION... Issued at 427 PM CDT Fri Jun 14 2024 ...Synopsis... Current water vapor depicts upper ridging over the central CONUS with an embedded, weak upper trough entrenched in richer moisture sourced from Pacific/Baja Coast over the Intermountain West and High Plains. Upper troughing over the northeast Pacific and PacNW is also noted. At the surface, high pressure centered within Minnesota is pushing east as lee troughing impinges upon the northern High Plains, currently resulting in scattered thunderstorms in western Dakotas. Ensemble guidance all agrees the upper ridging building and eventually stalling east into the eastern CONUS into Great Lakes region. This allows upper troughing and southwest flow aloft over the Norther Plains and Upper Midwest this weekend into early next week. The southwest flow aloft and surface troughing lee of the broader scale upper troughing will allow higher moisture and instability into the region. This sets the stage for multiple rounds of showers and thunderstorms starting tonight, lasting through Tuesday. ...Multiple rounds showers and storms through Tuesday, some of which will be strong to severe... Starting tonight, thunderstorms within central ND will advect east into eastern ND. Wind shear should be ample, although instability is forecast to be marginal, between 500-1000 J/kg. Thunderstorms will confidently be elevated in height this evening into tonight. Should instability fed into convection be on the higher end (MUCAPE around 1000 J/kg), thunderstorms would be capable of hail up to the size of quarters given strong shear/opportunity of organization as well as elevated nature of updrafts deeper into hail growth zone. This is the first of multiple rounds, with another round expected later Saturday evening into overnight as convection moves out of western and central ND into eastern ND. Should storms move into our area sooner before sunset, storms have a better chance of maintaining strong to severe characteristics, as well as better chance for bringing damaging wind gusts. If they come later, strong to severe storms would remain possible, albeit more isolated in coverage. In either scenario, hail would be the main impact. Guidance then starts to deviate in solutions on area, timing, and magnitude of thunderstorms (of which may still be severe). Some ensemble guidance pushes a cold front thorugh the area Sunday quicker, limiting severe chances to our far south/east or even away from our area. On the other hand, some guidance members slow the cold front, which would result in better opportunity for organized convection holding severe characteristics. This also bleeds into Monday where the cold front is expected to eventually stall within or south of our area, and perhaps make a jaunt back northward ahead of a stronger shortwave impulse traveling through southwest flow aloft. Should the front push deeper into our area bringing more moisture/instability, the chance for severe weather increases (vice versa if the front stays stalled further south). While holding least confidence, Tuesday also holds a chance for organized convection as upper troughing may be slow to move away from our area. Not to be discounted is the flooding potential. Numerous thunderstorms and higher rainfall rates from these rounds may prime the area/soils to become more susceptible to flooding, especially on Monday where guidance strongly suggests this is the time period where highest available moisture content interacts with forcing aloft. Additionally, if the aforementioned stalled front orients itself more parallel to the flow aloft (southwest-northeast), this would focus numerous, strong thunderstorm development, of which would have the chance to train or backbuild. Location of areas most at risk to see flooding impacts remains uncertain at this time. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1112 PM CDT Fri Jun 14 2024 Rain continues to move through DVL, GFK, TVF, and BJI this evening, with a few isolated showers around FAR. Chances for rain continue through the overnight period, with a few lingering shower chances through mid morning. Potential for VCTS in DVL over the next several hours. Otherwise, we are looking at winds increasing out of the south around 12-15z for eastern ND and the Red River Valley. Gusts reach 30-35kts for DVL, FAR, TVF, and GFK around 15-18z and continue through 02z. MVFR ceilings move in from the west and south tomorrow around 18z for DVL and GFK. Further chances for rain and storms tomorrow afternoon and evening. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Spender DISCUSSION...CJ AVIATION...MM/Spender