FXUS63 KBIS 290234 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 934 PM CDT Sat Sep 28 2024 .KEY MESSAGES... - Above normal temperatures and dry conditions will continue through the weekend, with possible record high temperatures in the 90s on Sunday. - Critical fire weather conditions are expected on Sunday across central and portions of southwestern North Dakota. Near critical fire weather conditions elsewhere. - Breezy to windy conditions central and east Sunday, and windy area wide on Monday. - Cooler temperatures next week. Low temperatures will drop into the 30s to low 40s, with high temperatures forecast in the mid 50s to upper 60s. && .UPDATE... Issued at 932 PM CDT Sat Sep 28 2024 A quiet night continues across western and central North Dakota under a clear sky. Lows will be quite mild for this time of year, forecast to range from the lower 50s north, to the upper 50s and lower 60s south. For this update, just blended in the latest observations to the going forecast. UPDATE Issued at 608 PM CDT Sat Sep 28 2024 No major changes were needed for the early evening update. Just blended in the latest observations to the going forecast. && .DISCUSSION... Issued at 220 PM CDT Sat Sep 28 2024 Currently, a clear sky across the Northern Plains with a large ridge of upper level high pressure anchored over the central CONUS. Unseasonably warm temperatures for late September this afternoon, with current readings well into the 80s many areas along with low relative humidity and a light easterly breeze. Main weather highlight in the short term period will be even warmer temperatures on Sunday, along with critical fire weather conditions. Upper ridge axis will shift to the east as a well defined mid level S/WV moves onshore and advances inland across the far Pacific Northwest/Southwestern Canada. Associated sfc/mid level low strengthens in the lee of the Alberta/Montana Rockies tonight into tomorrow, with increasing southerly flow into the region. This will promote continued WAA across the Dakotas, with likely record high temperatures on Sunday many locations across western and central North Dakota. Increasing boundary layer temperatures coupled with moderate to strong mixing will also result in another afternoon of low relative humidity and an increase in critical fire weather conditions. See Fire Weather Discussion Below for more information on fire weather. Wind headlines will also be possible, but will defer this to later shifts. The aforementioned S/WV will continue east along far southern Canada Sunday night and Monday, and will drive a cold frontal passage through the region later Sunday evening into the day Monday. Resultant weather will be northwest winds increasing (wind headlines are likely) along with much cooler temperatures surging into the region (Highs Monday upper 50s northwest - low 70s southern James Valley), around 20-35 degrees cooler than Sunday. Only chance of precipitation with this wave will be across the north, with dry conditions expected elsewhere. A quasi-zonal flow pattern is then forecast for the remainder of the work week, with mainly dry weather conditions and temperatures more seasonal. The probabilities for morning frost and minimum temperatures dropping to around freezing will also increase next week (it is late September/early October after all), with the cooler mornings right now forecast for Tuesday and Friday mornings. In addition, can't rule out more elevated fire weather concerns next week, as fuels cure and we see dry/breezy days ahead. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 608 PM CDT Sat Sep 28 2024 VFR conditions are expected through the period. All sites across the west and central could see a few hours of enhanced low level wind shear overnight and into early Sunday morning (all major sites in the forecast area except for KJMS). Southerly winds will also be on the increase early Sunday morning, lasting through the afternoon. Gusts up to 32 knots will be possible, especially across the James River Valley. && .BIS WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 11 AM CDT /10 AM MDT/ to 10 PM CDT /9 PM MDT/ Sunday for NDZ011-012-019>022-033>036-041-042-044>047-050. && $$ UPDATE...ZH DISCUSSION...NH AVIATION...ZH