Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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916 FXUS63 KBIS 260557 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 1257 AM CDT Sun May 26 2024 .KEY MESSAGES... - Patchy frost is possible in far north central North Dakota tonight, with the highest chance in the Turtle Mountains area. - Patchy fog is possible across portions of western and central North Dakota overnight, mainly in the Lake Sakakawea area and south. - Breezy west to northwest winds are expected Sunday and Monday. - Shower and thunderstorm chances (50 to 70 percent) return late tonight and continue through Monday morning. - Expect a brief dry period Tuesday into early Wednesday, with an active weather pattern returning for the rest of the week after. && .UPDATE... Issued at 1242 AM CDT Sun May 26 2024 A little light shower activity continues to the east/southeast of Bismarck, while along the Montana border showers with a few light thunderstorms continue to move into the area. Adjusted precipitation chances accordingly with both these areas. UPDATE Issued at 954 PM CDT Sat May 25 2024 The two areas of radar returns from earlier continue slowly moving east across south central North Dakota, with lightning still observed in the northern-most cell. Updated POPs in line with these trends, with uncertainty in low long they will persist over the next couple of hours. We did go ahead and issue a Frost Advisory for Renville, Bottineau, Rolette, and Pierce Counties for tonight into Sunday morning. Since satellite imagery showed most of the snow had melted under mostly sunny skies today, and latest high-res guidance is advertising slightly drier low levels compared to earlier, we think that patchy frost is possible across this area. We did also freshen up POPs for late tonight through tomorrow as a more substantial shortwave moves through the area. The only noticeable change with this update was to move up the start time by a couple of hours, with the time of arrival tool putting ongoing convection in eastern Montana at the state line in the next 2 to 3 hours. Expecting shower activity with a few thunderstorms to be pretty widely scattered until the late morning tomorrow, when CAMs are advertising coverage will increase in central North Dakota. UPDATE Issued at 655 PM CDT Sat May 25 2024 Mostly quiet across the area this evening, with relatively light winds and widespread fair weather cumulus that will diminish through the evening with the loss of daytime heating. Radar returns continue across the ND/SD border in Bowman and Adams Counties, as well as to the north in Billings and Stark Counties as of 2330 UTC. We did add in mention of isolated showers and thunderstorms across the southwest and into the south central through the evening, but overall not expecting much with this activity. Additional precipitation is upstream in central Montana with an approaching shortwave. Only other forecast feature we will continue to look at tonight will be frost potential in the Turtle Mountains area. Webcams and satellite imagery show the majority of snow since yesterday has melted off, with a few localized areas still broadly snow- covered. && .DISCUSSION... Issued at 143 PM CDT Sat May 25 2024 Currently the stacked low from the past few days is sitting north of Minnesota. We have low diurnal cumulus forming in the cyclonic flow across the area. Aloft, flow is mostly zonal south of the low, with a slight ridge in eastern Montana and a shortwave west of that. Tonight will be warmer than last night with lows in the 40s. We lowered temperatures where the snow fell by blending in the NBM 50th with the NBM. Up there any non snow covered areas could get frost. With lower confidence in the frost and warmer temperatures we choose not to do a frost advisory. The only areas that have a chance of frost are most likely snow covered anyways. There might be patchy fog around Glen Ullin and Bismarck, and north like this morning. We will remain dry until later tonight when the shortwave opens up over the west. Timing looks to be sometime between 06z and 10z depending on what CAM you look at unfortunately. These will most likely just be rain showers until some daytime heating kicks in for some energy. Then our chances for thunder goes up to 45 percent after 1pm central time. The showers will move off to eastern North Dakota with the low pressure Monday morning. The chances will slowly go down after 7pm central time Sunday. Rain totals look to be around 0.25 to 0.40 mainly east of the river. Of course there could be higher amounts in thunderstorms, otherwise it looks like a quick moving system. Winds will get slightly breezy in the western counties from the west. A pressure rise bubble mainly in Montana will be present with a slightly tight pressure gradient. Monday, Memorial Day, will be drier than Sunday but still a 30 percent chance of showers east of the river. This is from some potential wrap around moisture and cyclonic flow aloft. The south this time will have the tighter pressure gradient from the low, so expect breezy winds through the evening. After Monday a tall ridge with warmer 850mb temperatures moves in. We will be dry with temperatures warming to the 70s west of the river Tuesday where the thermal ridge is set up. Wednesday will be the warmest day with the warm thermal ridge and breezy south winds. Highs will be near 80 in the west and lower 70s east. Our active southwest flow returns Wednesday night when a big trough digs through the Pacific Northwest. Chance of showers and thunderstorms will be in the forecast late Wednesday evening through Friday. Temperatures look to stay in the 70s. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1242 AM CDT Sun May 26 2024 Numerous rain showers with isolated to scattered thunderstorms will spread from west to east over western and central North Dakota today into this evening. Localized visibility reductions to IFR/MVFR will be possible in the heavier precipitation. Otherwise, VFR conditions are expected. && .BIS WATCHES/WARNINGS/ADVISORIES... Frost Advisory until 8 AM CDT this morning for NDZ003>005-013. && $$ UPDATE...JJS DISCUSSION...Smith AVIATION...JJS