Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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096 FXUS63 KBIS 060017 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 717 PM CDT Fri Jul 5 2024 .KEY MESSAGES... - Scattered showers and thunderstorms (30 to 60 percent) will continue this evening across western and central North Dakota. Some stronger gusts are possible in the far west through 9 PM CDT. - Daily chances (30 to 60 percent) for showers and thunderstorms continue through the weekend. - A gradual warming and drying trend is expected for next week. && .UPDATE... Issued at 714 PM CDT Fri Jul 5 2024 Showers and thunderstorms have become more widespread across the western half of the state since late afternoon, while remaining more isolated along and east of Highway 83. The strongest storms in North Dakota, which since 6 PM CDT have been widely scattered along a meridional corridor from Burke to Hettinger Counties, have shown signs of producing hail around half an inch in diameter or smaller. These storms have been very pulse in nature given the moderate CAPE/no shear environment. Another broken line of storms moving across eastern Montana has a history of producing gusts to around 60 mph from around Glasgow to Poplar, and now more recently at Glendive. The environment there is similar to western North Dakota, with perhaps just slightly stronger 0-3 km bulk shear (still less than 30 kts) but negligible effective bulk shear. With the slight enhancement in 0-3 km shear expected to translate eastward with the line of storms, a few gusts in the 50 to 60 mph range cannot be ruled out across far western North Dakota through 9 PM CDT. At around 4 PM MDT, at least one cold air funnel was spotted near Dickinson. No other reports have been received anywhere else since, and the low level buoyancy needed to produce these funnel clouds is now waning. Until we see a more distinct pattern shift, which as noted below is forecast to commence on Monday, conditions could materialize to support afternoon cold air funnels with showers and storms through the weekend. && .DISCUSSION... Issued at 223 PM CDT Fri Jul 5 2024 The weather pattern today looks quite similar to yesterday. Weak progressive ridging is currently located over western and central North Dakota and this feature has been the main reason showers and storms have been a little slower to get going than yesterday. That being said, another fast moving upper low will track into the area later today and tonight, bringing more scattered showers and isolated to scattered thunderstorms (30 to 60 percent chance). The severe weather potential remains low. While MLCAPE will max out around 1000 to 1500 J/kg, shear will be very low. Still, given slow storm motions, locally heavy rainfall will be possible along with some small hail and frequent lightning. Given the lack of shear, weak funnels/landspouts could be a concern similar to yesterday, but the upper low has moved well east so background vorticity is not as elevated. Thus, we do not think the threat is as high but SPC mesoanalysis does suggest some pockets of the non- supercell tornado parameter up to one, likely driven by the weak shear and strong low level CAPE. Highs this afternoon will be in the 70s. The story remains pretty much the same for Saturday and Sunday with more chances of showers and thunderstorms (30 to 70 percent) with the best chances currently looking like Saturday afternoon. Severe weather chances remain low given a similar environment as today. Highs will mainly be in the 70s again on Saturday and Sunday but we may start to see some lower 80s by Sunday. We dry out on Monday as an expansive western ridge finally starts to nudge into the region. There could be a window for a few showers or storms across the north central and northeast on Tuesday as a weak wave rides down the ridge but we are talking maybe a couple hundredths of liquid at the most. Expect a gradual warming trend through the week with some upper 80s back in the forecast by Wednesday and some lower 90s by the end of the week. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 714 PM CDT Fri Jul 5 2024 Scattered showers and thunderstorms remain possible across western and central North Dakota this evening through tonight. KJMS has the lowest probability of showers and storms this evening. Meanwhile, storms entering the state from eastern Montana between 00Z and 02Z could produce gusty northwest winds as high as 30 kts. Other showers and storms are far less likely to produce gusty winds, but a brief period of IFR visibility can be expected with any heavier shower or storm. Later tonight through Saturday morning, the highest chances for showers and perhaps a few thunderstorms will focus more over south central and into southeast North Dakota, with coverage of showers and storms once again expected to become more widespread across the state Saturday afternoon. Outside of showers and storms, VFR conditions and light winds are expected through the forecast period. Some smoke from Canadian wildfires has been noted aloft, but it is unlikely to significantly impact aviation.&& .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hollan DISCUSSION...ZH AVIATION...Hollan