Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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569 FXUS63 KBIS 131445 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 945 AM CDT Mon May 13 2024 .KEY MESSAGES... - There will be daily chances for showers and thunderstorms through the week. A few storms may become strong this afternoon and evening in the west. - Near average temperatures are expected this week, with highs in the mid 60s to mid 70s and lows in the 40s. && .UPDATE... Issued at 945 AM CDT Mon May 13 2024 No major changes to the forecast were performed at the time of this update. Winds are light out of the east to southeast, while mid level clouds continue to push into the northwest. Weak radar returns are moving across the northwest with these clouds, but the lack of observations and 10 to 20 degree dewpoint depressions indicates that it may be having trouble reaching the ground at this time. Otherwise, a thin layer of smoke aloft continues to linger over the forecast area through the day today. UPDATE Issued at 635 AM CDT Mon May 13 2024 Some low to mid level clouds are moving into the northwest along a weak boundary, along with some weak radar returns in the area. While we continue to keep some PoPs in the northwest associated with this, we haven`t been seeing many reports of rain reaching the ground from it. Otherwise, mostly clear skies and light winds remain over much of the area, with upper level smoke beginning to show itself on visible satellite imagery once again. && .DISCUSSION... Issued at 318 AM CDT Mon May 13 2024 Presently, a surface low sits across Montana, while mid-level ridging is present across much of the Rocky Mountains and Northern Plains. At the moment, much of the area is under clear skies and calm winds, with widespread temperatures in the upper 30s to lower 40s. Some areas may see temperatures in the mid 30s, though the areal extent of these cold patches aren`t large enough to warrant issuing a Frost Advisory. The near-surface smoke from the Canadian wildfires has exited the area for the most part, with any remaining smoke only present in the upper atmosphere. As the day progresses, a shortwave trough riding the top of the aforementioned ridge will bring about the next chance of precipitation for much of the area. Some showers and thunderstorms have already developed along the associated surface boundary across parts of northern Montana and southern Saskatchewan. As such, chances for precipitation will arrive in the northwestern portions of the state in the early morning hours, slowly spreading east throughout the rest of the morning as the trough continues moving east. These chances will remain rather low, around 20%, due to the relatively dry air near the surface, as indicated by forecasted dewpoint depressions in the 20 to 30 degree range. Through the afternoon and early evening hours, there will be a slight chance for some thunderstorms, due to a very narrow corridor of instability entering the state from the west. However, most recent deterministic guidance suggests instability maxing out around 500 J/kg, mostly across the border with Montana. As a result, the likelihood of any thunderstorms being strong to severe is rather low. While there will be plenty of 0-3 km shear across the north central portion of the state, this shear maximum will be displaced from the instability maximum. The threat for any strong storm will be highly conditional, and will likely only be possible in the very narrow region where these two maximums overlap. For now, the SPC has placed us in a General Thunderstorm risk area. Warm temperatures are expected again today, with widespread highs in the upper 60s and 70s. Showers will continue overnight as the shortwave moves east, with chances for rain increasing into the overnight hours. Most of the area will see a 50 to 70% chance for rain tonight, with chances decreasing to the southeast and into the southern James River Valley. Overnight lows will mostly be in the 40s and lower 50s. A surface low is forecast to develop across South Dakota early Tuesday morning, moving east with the previously mentioned shortwave trough. This may bring continued showers along the northern periphery of the low, keeping chances for rain across the area in the 40 to 70% range through the day Tuesday. The highest chances look to be in the southwest and central areas of the state, with chances decreasing to around 20% in the northwest. There`s a slight chance (roughly 15 to 30%) for some thunderstorms associated with these showers. Severe storm potential is currently minimal. This active showery pattern is then expected to continue through the rest of the week, as multiple shortwaves and disturbances pass across the Northern Plains. Near daily chances for showers and thunderstorms persist into the weekend. High temperatures for each day will remain firmly in the mid 60s to mid 70s. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 945 AM CDT Mon May 13 2024 VFR conditions are present across all terminals at the moment, with light winds generally out of the east or southeast. Clear skies are present at all terminals except KXWA, which should be seeing some lower clouds approach over the next few hours, moving in from the west. Some light showers may be embedded in this cloud deck as well. Winds will shift to be more southeasterly during the afternoon today, with speeds increasing through the day as well. Winds will increase to the 15 to 20 kt range, with some gusts up to 25 to 30 kt possible in the late evening hours. A front will bring about some showers and possibly some thunderstorms from west to east, arriving in the west at around 00z, expanding east through the 2nd half of the TAF period. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Adam/Besson DISCUSSION...Besson AVIATION...Besson