Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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631 FXUS63 KBIS 071743 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 1243 PM CDT Sun Jul 7 2024 .KEY MESSAGES... - Another round of scattered showers and thunderstorms is expected this afternoon and early evening. Some storms may once again produce funnel clouds, with a weak landspout tornado possible. - The daily potential for showers and storms will focus more over eastern North Dakota Monday and Tuesday, with coverage becoming more isolated. - A warming trend is expected this week, with widespread highs in the 90s likely on Friday. && .UPDATE... Issued at 1243 PM CDT Sun Jul 7 2024 At 1230 PM CDT, a lone batch of showers with an embedded thunderstorm was crossing from western Sioux and eastern Adams Counties into South Dakota. Meanwhile, midday satellite shows increasing cumulus along and south of Interstate 94 from eastern Sioux County through the southern James River Valley, where radar returns are just now beginning to increase. Current SPC mesoanalysis shows the non-supercell tornado parameter in LaMoure and Dickey Counties ranges from 1 to as high as 3, so will be on the lookout for funnel clouds reports once again. UPDATE Issued at 849 AM CDT Sun Jul 7 2024 Patchy fog and low ceilings have developed over Foster and eastern Stutsman Counties. Conditions are likely to improve by around 10 AM. For the rest of the morning, shower activity will likely remain confined to southwest parts of the state, where an ongoing batch of southward moving showers was crossing Interstate 94 between Dickinson and New Salem as of 845 AM CDT. Very infrequent lightning has been observed on the northeast side of these showers, and do not expect any significant uptick in lightning through the morning. UPDATE Issued at 600 AM CDT Sun Jul 7 2024 Two distinct circulation centers are evident via satellite within the large scale trough over the region. Departing S/WV centered over northern Minnesota and another embedded wave over portions of southwest ND/northwest SD. In addition, there is another more subtle impulse dropping south across western North Dakota, resulting in elevated cloud cover there along with an area of scattered showers and isolated thunderstorms advancing south with the impulse. Also scattered showers continue over my southeast, more associated with the S/WV to our east. For this update, modified POPs and sky cover based on latest imagery and trends. && .DISCUSSION... Issued at 355 AM CDT Sun Jul 7 2024 Currently, quasi-stationary long wave trough remains over the region early this morning, with strong ridging over the west coast. Within the trough, multiple embedded mid level impulses continue to rotate through, contributing to scattered showers and a few isolated thunderstorms. A more defined impulse developing south across western ND results in a decent coverage of showers and at times a few thunderstorms. This activity should continue south across my west now through sunrise. Will also maintain isolated mention elsewhere given the unsettled atmosphere in place this morning. For today, expect another day of scattered showers and thunderstorms, though we start to see the better coverage of precipitation more to the east as our persistent trough starts to develop farther to the east, anchored more over the Western Great Lakes/eastern Dakotas vs. centered over the central Dakotas. Mean flow aloft will be weak today across the east, so as we saw yesterday, there is some potential for a few heavy rainers with expected slow moving convection. In addition, the non-supercell Tor parameter (NST) is also similar to Saturday when we received multiple funnel cloud reports and one confirmed landspout tornado, so wouldn`t be surprised to see another day of this today during the daytime hours. Showers and isolated storms will continue into this evening, before diminishing later tonight as sfc high pressure builds into the region and flow aloft becomes more north/northwesterly. The aforementioned strong upper level ridge over the west coast will develop farther inland into the Intermountain West Monday into Tuesday, maintaining flow aloft over the Northern Plains out of the north/northwest. NBM has maintained low POPs over my far east both days, and can`t argue with this as any wave within the flow could fire off diurnally driven convection. Most of western and central North Dakota will remain dry however. Temperatures are still favored to slowly warm through next week, approaching seasonal normal values (low/mid 80s) by the middle of the week. Upper ridge broadens and expands across the Rockies later in the week, when temperatures are favored to be well above normal, with highs Thursday-Saturday forecast in the mid/upper 80s to mid 90s. While we should be mainly dry after early next week, there is increasing potential for thunderstorms next weekend when the ridge flattens over the Northern Plains and when models depict favorable upper level jet dynamics aloft as a S/WV trough swings east across Canada. NBM put in slight chance POPs Fri- Sun, along with the CSU machine learning indicating some low severe probabilities during that timeframe. Thus, something to keep an eye on. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1243 PM CDT Sun Jul 7 2024 Scattered showers and thunderstorms are likely to develop once again this afternoon and evening. The highest confidence in coverage of showers and storms is from around KBIS to KJMS, where VCTS has been included. Elsewhere, coverage is likely to be more widely scattered to isolated, and far western North Dakota could remain completely dry. Any heavier shower or storm could produce brief periods of MVFR to IFR visibility. Otherwise, VFR conditions are likely through the forecast period. Some patchy fog could develop late tonight into Monday morning, but confidence on exact location is low. Northwest winds around 10-15 kts this afternoon will become light after sunset. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hollan DISCUSSION...NH AVIATION...Hollan