Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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286 FXUS63 KFGF 151746 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1246 PM CDT Wed May 15 2024 .KEY MESSAGES... - Showers and isolated thunderstorms are expected today across much of the area, with a low chance for a few stronger storms in west central Minnesota. - Thunderstorms on Friday afternoon have a chance to be strong to severe. The probability for widespread severe thunderstorms is low. - Active pattern continues into the weekend and next week, with several more chances for showers and thunderstorms. && .UPDATE... Issued at 1246 PM CDT Wed May 15 2024 Showers are ever so slowly moving northeast with the average observation reporting a couple tenths almost as far north as highway 200. Lightning is being produced in the northern devils lake basin and into Canada. The showers look to take a break around 03z for most of the region tonight and continue again tomorrow afternoon. UPDATE Issued at 1034 AM CDT Wed May 15 2024 Looking at observations the northern river valley and southeast North Dakota moving into the southern river have precipitation falling. A few bolts of lightning are still being produced near the fergus falls area. I modified POPs to reflect these occurrences and trying to time out the moving wave as showers develop in the central valley. Maybe if the clouds break we might get a few thunderstorms in the afternoon but chances are currently looking very slight as the HRRR is the only one depicting convection in the afternoon. UPDATE Issued at 645 AM CDT Wed May 15 2024 Radar returns are beginning to increase in southeastern North Dakota this morning, with still a bit of dry air keeping much of the rain from reaching the ground. Precipitation will gradually overcome this dry layer this morning as rain pushes to the north and east. Temperatures remain on track, with mid to upper 40s along the International Border and mid 50s in southeast North Dakota. && .DISCUSSION... Issued at 355 AM CDT Wed May 15 2024 Today into tonight: Look for an increase in shower activity this morning, with isolated embedded thunderstorms this afternoon. Best chance for thunderstorm activity today will be in the southern portions of the Red River Valley and west central Minnesota. Severe thunderstorms are not expected this afternoon; however, isolated small hail cannot be ruled out. Soundings indicate the potential for around 1000 J/Kg of MUCAPE, along with SFC-3km shear up to 25 knots. This, along with the position of the upper low, could potentially allow a brief period this afternoon where we could see weakly organized thunderstorms. Shower and thunderstorm activity from this first system will push off to the east and northeast overnight. Rainfall totals through Thursday morning will range from 0.10 inch near Devils Lake to 1 or more inches in the southern Red River Valley (70 percent chance). Thursday: Another shortwave moves across the area Thursday, bringing mainly isolated showers and thunderstorm activity to the area. Rainfall potential on Thursday is much lower, with about a 40 percent chance to see 0.10 inch or more precipitation around Devils Lake, and 20 percent elsewhere. Friday: Our next chance for more widespread rain occurs Friday as another shortwave moves across the area. Looking at ensemble members, there is a fairly large number of potential solutions that involve strong thunderstorms. SBCAPE ahead of the main system has a 70 percent chance to exceed 1000 J/Kg and a 20 percent chance to exceed 2000 J/Kg in southeastern North Dakota. Low to mid level shear (0-1km and 0-3km shear) support organized thunderstorms, with much weaker deep layer shear potential. There will be a relatively strong theta-e gradient to provide lift and initiation during the afternoon and evening hours. Mode is somewhat uncertain at this time; however, a supercell or two cannot be ruled out, although most soundings show better chances for multicell convection or hybrid type storms. For the weekend and into next week: Lingering showers and thunderstorms are possible through around midday Saturday as zonal flow takes over across the Northern Plains. This will be relatively short lived in this progressive setup, and another shortwave is expected to impact the region starting Sunday afternoon. Early indications show another chance for showers and thunderstorms, with a few stronger storms not out of the question. Progressive flow brings several more shortwaves across the area Monday through Wednesday, with a large degree of temporal and spatial variation at this time. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1246 PM CDT Wed May 15 2024 For the most part VFR look to continue through this afternoon however ceiling look to start to drop this evening and continue through tomorrow into the MVFR/IFR. Winds will also continually shift throughout the night due to the interaction between the upper low to our south and a surface low to our west. This interaction is causing some uncertainty in timing for the windshift and how low the cloud ceiling will drop. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...MM DISCUSSION...Lynch AVIATION...MM