073 FXUS63 KBIS 070017 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 617 PM CST Sun Nov 6 2016 .UPDATE... Issued at 606 PM CST Sun Nov 6 2016 Have decided to remove shower/thunderstorm chances over the southern James River Valley this evening. High res models have backed off with precipitation chances, and instability has diminished. Otherwise, remainder of forecast looks good. && .SHORT TERM...(This evening through Monday) Issued at 227 PM CST Sun Nov 6 2016 Latest water vapor imagery loop indicative of southwest flow aloft with increasing moisture/clouds especially across central ND. A leading shortwave was seen across northeast Montana moving into southeast Saskatchewan this afternoon. Local radar continues to shows some mid level returns across northern ND. Possibility of a shower or two developing through the afternoon as another shortwave in southwest ND moves northeast into north central ND. Will maintain an isolated shower mention across the north central until 00Z Monday, as is supported by the operational GFS, GFS Ensemble Mean, and the SREF precipitation forecasts. A Pacific shortwave trough now working through northwest Montana into southern Alberta will move east with time, shifting through western and central ND during the day Monday. An associated surface cold front will sweep through western and central ND tonight. Lastly, a couple of weak shortwaves were seen circulating within the southwest flow across western and central South Dakota. These shortwaves are associated with the closed upper low that was over the four corners the last few days and is now an open wave over the southern plain states. Expect these shortwaves to impact the southern James River Valley this evening. That being said, weak instability is evident across far south central ND per SPC Mesoscale Analysis page with most unstable cape around 100 J/Kg, mid level lapse rates 7.5C/km, and Pwats between 0.7 and 0.9 inches. This is forecast to slide into the James River Valley this afternoon and evening. Hi-resolution models suggest that if precipitation does develop, then the favored area is eastern LaMoure and Dickey counties between 00z and 06z Monday. Forcing per Q-vector Divergence field is weak, and given the limited areal coverage of the above mentioned instability field, will keep the a mention of the shower/thunderstorm potential, but limit it to the far southern James River Valley this evening. Behind the surface cold front Monday, H85 temps fall back to between +2C to +4c Monday afternoon. This replaces our recent warmth which was linked to H850 temps between +14C and +16C. Thus highs Monday will be in the 50s, which is still above normal highs for this time of year. Area of clouds now in western Alberta will break off in the northwest flow behind the cold front and slide into northern ND Monday. Hence expect more clouds than sun north Monday, with increasing sunshine farther south. In addition with northwest winds 15 to 30 mph, it will feel a bit more crisp all around versus previous days when we had no wind. .LONG TERM...(Monday night through Sunday) Issued at 227 PM CST Sun Nov 6 2016 Another ridge rebuilds across ND Tuesday into Wednesday with H850 temperatures returning to +14C to +16C by Wednesday afternoon. Thus we continued the trend of adjusting given gridded guidance upward to match highs closer to what has been occurring under these conditions. With ample sunshine both days, highs Tuesday will reach between 55 and 65 degrees; and upper 60s to lower 70s Wednesday. If this trend continues, record highs in Bismarck and Williston would be reached Wednesday, with near record highs at Dickinson and Minot. Another cold frontal passage will occur Wednesday night with cooler and breezy conditions Thursday. Still no threat of any precipitation with these frontal passages. High temperatures will return back into the 50s Thursday and Friday. Brief ridge builds in again Friday and Saturday, but thereafter, there seems to be a trend toward more frequent cold frontal passages, which would limit any significant warming as we had in previous days. Earliest signs for any measurable precipitation possibly just beyond this long term period, that being Monday. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 606 PM CST Sun Nov 6 2016 MVFR cigs possible Monday morning through mid-day over north central North Dakota as a weak disturbance moves through. Elsewhere...VFR conditions are expected to prevail. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...KS LONG TERM...KS AVIATION...JJS