564 FXUS63 KFGF 050320 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1020 PM CDT Wed Jun 4 2025 .KEY MESSAGES... - Additional showers and thunderstorms Thursday into Friday, mainly south of I-94. Severe impacts are not expected, but there could be some lightning and a 40 percent chance for a quarter of an inch or more of rain. && .UPDATE... Issued at 1020 PM CDT Wed Jun 4 2025 Conditions remain quiet this evening. With the loss of daytime heating, the handful of remaining thunderstorms have dissipated, with just a few sprinkles left over. They too should come to an end soon. Adjusted grids to match cloud cover, otherwise forecast remains on track. UPDATE Issued at 638 PM CDT Wed Jun 4 2025 Pop up storms over the past few hours have produced wind gusts of 40 to 50 mph. Recent radar and satellite trends show that storms are weakening, with little new development to take its place. Therefore, conditions should continue to quiet down through sunset. Forecast remains on track. && .DISCUSSION... Issued at 248 PM CDT Wed Jun 4 2025 ...Synopsis... Broad trough continues over most of south central Canada and the north central CONUS, with several shortwaves moving through. One such shortwave near the SD border is currently causing a cu field and showers to develop south of the Highway 200 corridor. Another shortwave moving into SD/Nebraska Thursday and yet another one in the same area on Friday. By Saturday, a stronger northern branch shortwave will start digging down into the Plains, shifting into the Great Lakes by Sunday. North to northwest flow for the early part of next week, then a warming trend as weak upper ridging moves in. ...Showers and isolated thunderstorms this evening... Scattered showers and a few thunderstorms have developed across North Dakota as the shortwave moves through the Northern Plains and there has been destabilization to 250-500 J/kg of surface based CAPE. Effective shear is around 15 to 20 kts, so not expecting any organized convection. However, some of the model soundings show an inverted V at the low levels indicating wind potential. Will have to watch for collapsing cores. Currently not even getting too much lightning activity yet, but the cumulus towers are showing glaciation, so will keep an eye out for strikes potential near our decision support sites. By late evening, the shortwave will be east of our CWA and daytime heating will be on the wane. Showers should taper off by late evening. ...Rainfall and some thunder in south Thursday/Friday... A shortwave moving through South Dakota and Nebraska Thursday and another vort lobe taking a similar track Friday will bring some precipitation to our southern counties for the end of the week. CAPE values look like they will remain under 500 J/kg so not expecting any severe impacts. However, there is a 40 percent chance for lightning activity from the HREF and can`t completely rule out thunder Thursday afternoon. The HREF is also showing at least some high probabilities of wetting rain over a tenth of an inch, and even a 50 percent chance for a quarter of an inch or more along the South Dakota border. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1020 PM CDT Wed Jun 4 2025 VFR throughout the TAF period. The biggest question that remains is how widespread pop up thunderstorms develop Thursday afternoon. Kept any mention of pop up thunderstorms out of the TAFs currently, but they may need to be added in future TAF sets as storms areal coverage and placement becomes more apparent. Winds will mostly be light and variable throughout the TAF period. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Rafferty DISCUSSION...JR AVIATION...Rafferty