Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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944 FXUS63 KFGF 030306 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1006 PM CDT Sun Jun 2 2024 .KEY MESSAGES... - There continues to be a slight (2 out of 5) risk for severe thunderstorms this afternoon and evening. Hail up to golf balls, wind gusts of 60 mph, and a few tornadoes possible. - Widespread showers and thunderstorms expected late Monday night into Tuesday. Severe storms are unlikely, but some impacts from heavy rain as there is a 50 percent probability of an inch or more. && .UPDATE... Issued at 1006 PM CDT Sun Jun 2 2024 Expanded the watch into Wilkin and Grant and ran the whole area until 11pm for now for the line to work its way southeastward through the southern forecast area. Starting to get into less instability, but shear remains strong. Shear gradient and moisture inflow should allow the line to continue its work southeast out of the forecast area in the next hour or two ending much of the widespread severe threat across the forecast area. Some light showers or weak thunderstorms will still be possible in the eastern half of the forecast area until the cold front pushes through later tonight. && .DISCUSSION... Issued at 321 PM CDT Sun Jun 2 2024 ...Synopsis... Southwesterly flow aloft with several embedded vorts continues across the Northern Plains. The main shortwave tonight will push off into Minnesota and Ontario, pushing the surface trough currently over the central Dakotas into the Upper Midwest by Monday morning. This will be quickly followed by the next shortwave, which will dig into eastern MT Monday night and into the Northern Plains by Tuesday. Northwesterly flow aloft sets up to mid to late week and into next weekend. ...Slight risk this afternoon/evening... Much of the morning and early afternoon has been a lot of non- severe convection for our forecast area, but starting to get some stronger cells in the far western counties and there has been some SPSs and one severe so far. In the last few hours there has been some more discrete cells developing in south central ND where there has been some clear skies and ML CAPE of 1500-2000 J/kg. Effective shear is around 30-40 kts, and while 0-1km SRH is not impressive, there has been one rotating storm just to our west in Stutsman county. CAMs continue to show the discrete cells moving into southeastern ND in the next few hours and then merging into a more linear form later this evening. While there still an isolated tornado threat, mainly in southeastern ND, the main issue for us will be hail up to golf balls and then transitioning to winds over 60 mph later tonight. The storms will push into the MN side, exiting out of our eastern CWA border sometime around midnight. ...Rain Monday night into Tuesday... The upper low for the beginning of next week will be fairly vigorous and our CWA will again be in the warm sector as the system tracks from the Northern Rockies eastward into Manitoba and ND. The surface trough axis will push eastward into the Red River Valley during the overnight hours Monday night. Due to the timing of the system, the bulk of the forcing will be coming through during the time of day when we will not be getting good heating. CAPE values from the ensembles are pretty low, and HREF has a few paintball UH tracks but not a huge amount. Think probabilities of severe are pretty low, but we could see some decent rainfall Monday night into Tuesday as the trough axis swings through. Probabilities from the NBM are around 50 percent for over an inch of rain, mainly for northeastern ND but are 10 to 30 percent for other portions of the CWA. With the recent wet pattern, the rain will have to be watched for impacts. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 656 PM CDT Sun Jun 2 2024 Showers and some storms to impact most sites this evening. KDVL likely done with majority of the shra/ts activity for the forecast period. Majority of thunder threat to shift to the southern and eastern sites as of latest radar trends and best instability further south, however cannot be ruled out at KGFK and TVF isolated embedded in the shower activity through 03-04Z. Frontal boundary to move through late and shift winds around to the west to northwest with development of low clouds across the area. CIGS could drop to IFR into Monday. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ MESOSCALE...MJB UPDATE...MJB DISCUSSION...JR AVIATION...JR