Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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273 FXUS63 KFGF 301752 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1252 PM CDT Sun Jun 30 2024 .KEY MESSAGES... - There is a low chance for a strong thunderstorm to move into the Devils Lake basin late tonight. - There is a level 1 out of 5 risk for severe thunderstorms Monday afternoon and evening across much of the forecast area, with a level 2 out of 5 risk for severe thunderstorms along and south of Interstate 94. - Isolated to scattered showers and thunderstorms possible through mid week. A system may then bring numerous showers and thunderstorms to parts of the Northern Plains on Independence Day, with a low chance for severe thunderstorms. && .UPDATE... Issued at 1252 PM CDT Sun Jun 30 2024 A few cumulus clouds have formed around the Upper and Lower Red Lakes, while some mid level clouds are getting closer to our western FA border. Meanwhile, light winds remain east of the Red River Valley, while southeast winds are picking up to 5 to 10 mph range along and west of the Valley. Overall, no changes to the forecast are needed. UPDATE Issued at 951 AM CDT Sun Jun 30 2024 A very quiet start to the day, with no cloud cover and light winds. Expecting some cloud cover to enter the western FA later in the day and winds to pick up out of the south (but at most 10 to 15 mph west of the Red River Valley). So no impactful weather today. UPDATE Issued at 649 AM CDT Sun Jun 30 2024 Mostly clear skies this morning except for this small patch of high based clouds over the southern valley. Winds are calm this morning like expected however should start to pick up out of the south this afternoon and tonight. Showers may start later than originally expected and not arrived in the Devils lake Basin until Monday morning at least. && .DISCUSSION... Issued at 405 AM CDT Sun Jun 30 2024 ...Synopsis... Today, will be sunny throughout the day as the surface high sits over the Northern Plains. With that high pressure system winds should remain light and will slowly shift from the north to the south this morning. As the high pressure moves off to the east later this evening and into the overnight period we should start to see the clouds move into the region from the west. Monday, Our severe potential looks conditional as SPC has us in a Slight (level 2 out of 5) Risk for South east ND and small sliver of West Central Minnesota close to the Red River. The rest of Eastern North Dakota and Minnesota counties are in a Marginal Risk (level 1 out of 5) for severe thunderstorms. Our Bulk shear is enough (30-40 knots) to sustain any convection that develops in Central North Dakota and moves into the valley. The mid level lapse rates are between 7-8C moving in Central ND but become 6-7C as the storms move into the valley. The better Cape profile also starts dwindling moving from the Basin into the valley with out best CAPE and Lapse Rates actually being in the further south which is why I believe SPC put the slight in the southern portion of our area because its a slightly better environment. The NAM soundings show us capped at the lower levels presenting the idea of elevated hailers moving into our area. NBM CWASP is at a 60 for the 50 percentile for our area and CWASP90 percentile is 70-72 for Devils lake basin and 65 for the valley. So its not that excited for our severe potential. Looking through the progression for model soundings there might be some drizzle showers as some sounding have us saturated at the lower levels under that cap but my best guess for the severe potential looks to be late afternoon and evening. If we do develop severe thunderstorms I would think hail size would be around an inch and maybe winds up to 60mph however with that cap its very likely the winds will be sub severe and hail would be our biggest threat. Tuesday through Friday A broad trough pattern gives increasing chances for showers throughout the week. I dont know if the farmers necessarily wants to hear that or not but with the timing of these shortwaves we could have brief isolated showers throughout the week. Independence Day through the Holiday weekend could start out active on Thursday as another trough moves through the area. CSU-MLP showing an isolated severe risk on Thursday. Deterministic QPF values seem robust, although NBM probs for over an inch of QPF Thursday through Thursday night are around 10 percent at this time. After this wave moves through there looks to be mainly northwest flow which brings less of a chance for showers and thunderstorms and some near normal temperatures. If a ridge in the west can build more inland as some clusters suggest then those chances for precip get lower while temps get slightly warmer. Right now the forecast represents the NBM although is worth monitoring... && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1252 PM CDT Sun Jun 30 2024 Overall, a pretty low impact set of TAFs until late tonight. The main thing worth mentioning is that a decaying convective complex may reach portions of the FA around or after sunrise Monday. Not too confident there will still be too much thunder left with it, so have mentioned VCSH at a few sites for now. If the complex remains a little stronger than anticipated, this could be VCTS. If later shifts get a little more confident, they can adjust this as need be. Guidance has also been showing stratus (MVFR ceilings) overtaking the FA during the day Monday (mostly beyond this TAF period). Went with an MVFR ceiling at KDVL as a starter, but these MVFR ceilings may expand to other areas as well, around or after 18z Monday. Finally, wind speeds will really begin to increase slightly before or after sunrise. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Godon DISCUSSION...MM AVIATION...Godon