Area Forecast Discussion
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
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770 FXUS63 KBIS 212346 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 546 PM CST Thu Nov 21 2024 .KEY MESSAGES... - Below average temperatures through next week with highs mostly in the 20s and 30s, and lows mostly in the single digits to teens above zero. Even colder temperatures possible to start next week, though uncertainty remains higher. - A 80 percent chance of additional accumulating snow this weekend in the north, with much lower chances south. There is a 50 percent chance of at least 4 inches of snow mainly along the Canadian Border. && .UPDATE... Issued at 545 PM CST Thu Nov 21 2024 Quiet weather is found over western and central North Dakota this evening. We have made some minor updates to the sky grids to account for the latest trends with the high based stratus moving in across the west. Otherwise, the forecast remains on track. && .DISCUSSION... Issued at 112 PM CST Thu Nov 21 2024 A quasi-shortwave ridge and higher pressure is over us currently. A lot of moisture from the atmospheric river event happening on the west coast is crating all the clouds in the state. Tonight we lowered temperatures a few degrees using the 25th percentile of the NBM since it will be light winds with snowpack. With the cloud cover being mostly the high cirrus, strong radiational cooling should take effect. Our next snow making system will move in Friday night. A far Northern Rockies low will slide east off the mountains. The latest run of the models now has the path north of North Dakota. The north will still see snow, but the amounts have changed. Now there seems to be no possibility of 6 inches. Just the northern tier of counties have a 50 percent chance of 4 inches. More uncertainty now exist. Will it shift again? Different models have a closed low at 500mb and some have an open wave. So the intensity is also now in question. We will continue to wait and see if we need a Winter Weather Advisory for those few counties or not. Sunday and Monday look breezy with a tightened pressure gradient, so look for our coldest wind chills yet. Next week on the backside of this system northwest flow will dominate, bringing much cooler below average temperatures. Multiple shortwaves will also move through next week. These could bring light snow, but nothing major. High temperatures could be in the single digits, but the NBM spread is about 20 degrees for this time period. Low temperatures could be below zero across the north all of next week. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 545 PM CST Thu Nov 21 2024 VFR ceilings and visibility are mainly expected through much of the 00Z TAF period. MVFR to IFR ceilings will begin to move into northwestern North Dakota late Friday afternoon, spreading south and east to other terminals beyond the end of the TAF period. Additionally, patchy fog is possible late tonight into tomorrow morning along the Missouri River and across southern North Dakota, though confidence is too low at the time of this update to add visibility reductions to any given terminal. Otherwise, light snow is possible across the Canadian Border Friday morning. Light and variable winds are expected to persist overnight, before organizing out of the north through the afternoon on Friday. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Adam DISCUSSION...Smith AVIATION...Adam