FXUS63 KBIS 270545 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 1245 AM CDT Mon Apr 27 2026 .KEY MESSAGES... - Medium to high chances for precipitation overnight into Monday morning, mainly south of Highway 2. Forecast precipitation amounts have lowered even more. - Mainly dry conditions expected from Tuesday through the rest of the week. - Below average temperatures continue through the first part of the week, then a warming trend develops. && .UPDATE... Issued at 1245 AM CDT Mon Apr 27 2026 Showers continue over portions of western and south central North Dakota at the time of this mid night forecast. Near surface conditions across south central North Dakota are little more dry than anticipated, with dewpoint depressions of 15 to 25 degrees being pulled further south than previously forecast. CAMs are picking up on this trend as well, keeping precpitation across this area fairly scattered. Have opted to lower PoPs a bit to account for this trend. Cooler temperatures across portions of the west have allowed for a transition over to snow to occur a little more quickly than previously expected, with visibilities dropping as low as 2 to 3 miles when and where snow is falling. Have adjusted the timing of the rain to snow transition across the west accordingly with this update. Otherwise, no major adjustments to the forecast were performed at this time. UPDATE Issued at 1001 PM CDT Sun Apr 26 2026 Widespread rain across my southern 2 tier counties, with continued light snow northwest. Ceilings starting to drop along the I94 corridor now as moisture continues to push northward. Adjusted POPs based on these trends and latest radar imagery. Other forecast changes were minor. UPDATE Issued at 703 PM CDT Sun Apr 26 2026 The forecast for tonight remains mainly on track. Adjusted POPs a bit to delay the arrival of precipitation, though these changes were minor. Rain is rapidly developing and advancing north into southern areas of the state ahead of a northeastward moving embedded impulse, with another area of rain and snow along and north of a sfc trough from parts of eastern Montana into northwestern North Dakota. Will make adjustments to the forecast as needed this evening. && .DISCUSSION... Issued at 220 PM CDT Sun Apr 26 2026 Currently the famous upper level low that hasn't moved much in the last few days, has actually shifted north. There is a trough extending off the center down to northern California, leading to southwest flow across most of the rest of the CONUS. At the surface the Colorado Low is just forming on the mountain, but widespread rain is already on going in the Central and Northern Plains in the southwest flow. In eastern Montana and far northwestern North Dakota scattered snow showers have been on going. Little to no accumulations are expected. The bulk of the rain showers are located in central and southern South Dakota, along and south in Interstate 90. Temperatures today are slightly warmer and near normal as the southwest flow has some warm air advection. This evening the surface low will wrap up and move northeast, bringing the rain north into the state. It is expected to then continue raining through Monday morning in most of the state besides the far north. As in prior forecast runs, the NBM continues to move the bulk of the QPF east into Minnesota and we are now left with less than 0.50 inches in the entire CWA. The highest QPF amounts will likely be in far southeastern North Dakota where 1 inch could fall. With the strong surface low exiting the Northern Plains Monday morning, there will a tight pressure gradient and a slight pressure bubble in southeast North Dakota... it will be windy. The James River Valley will be the bullseye where gusts up to 45 mph are possible from the north. We held off on a Wind Advisory on this shift but will likely be needing one. The NBM was blended with some NBM 90th to just slightly boost the winds with the drier, cooler air. The rest of the week will be drier with multiple shortwave ridges, eventually leading to quasi-zonal flow possible late in the week. This in turn will lead to a slight warming trend where we could see temperatures return to near normal or above (60F) by Thursday. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1245 AM CDT Mon Apr 27 2026 Precpitation will promote MVFR to IFR ceilings across portions of western and south central North Dakota overnight, slowly improving from northwest to southeast through the day Monday. While much of this precpitation is expected to fall as rain, light snow is possible over the west, which could promote MVFR to IFR visibilities when and where it falls. VFR conditions are generally expected to persist across the north central. North to northeast winds are expected to strengthen overnight through this morning, becoming gusty over portions of south central North Dakota late Monday morning through the afternoon, before diminishing through the early evening. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Adam/NH DISCUSSION...JJS AVIATION...Adam