222 FXUS63 KFGF 100008 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 708 PM CDT Mon Sep 9 2019 .UPDATE... Issued at 639 PM CDT Mon Sep 9 2019 Widespread rainfall continues to lift to the northeast this evening. In its wake a small area of redevelopment of showers has occurred across SE ND near Valley City and points to the northeast. Will see this area of showers or even light drizzle continue to expand and spread to the north. Another area of concern will be along the SD/ND border and adjacent areas of west central MN where thunderstorms are developing along nearly stationary warm front in NE SD. Will need to monitor convective trends in this area for the next few hours as some guidance lifts strong or severe storms into that area. Primary threats will be hail up to an inch and wind gusts around 60mph. For the overnight will see showers end but replaced by patchy or areas of fog and possibly drizzle into the mid morning hours. && .SHORT TERM...(This evening through Tuesday) Issued at 348 PM CDT Mon Sep 9 2019 Rain chances linger in the forecast overnight as the region remains affected by upper level shortwave troughs progressing northeast toward the Canadian Prairie in southeast (or southerly) flow aloft. Widespread showers associated with mid level warm air advection and frontogenetical lift will continue to progress northeast overnight, gradually exiting the Devils Lake basin and the northern RRV this evening and eventually northwest and west central Minnesota overnight. Generally expect an additional one to three quarters of an inch of rain from lingering activity, except for localized higher amounts possible in thunderstorms. Potential for impactful weather through Tuesday is focused on potential for isolated severe thunderstorms across southeast ND and portions of west central MN this evening and potential for widespread fog development overnight into early Tuesday. Latest satellite imagery shows dry mid level air advecting eastward into eastern ND and SD in close proximity of the surface low, progged to track from central SD into north central MN tonight. This brings potential for destabilization that will combine with increasing deep layer environmental shear (resultant of increasing mid level winds) and increasing lift provided by the approaching, northward advecting warm front to pose some threat for severe weather this evening. Lots of uncertainty in this setup as deep layer shear and/or instability may not be strong enough to sustain supercells in the immediate forecast area, and mean cloud layer winds from the west and deep layer shear from the southwest semi- parallel to the front support upscale growth into clusters of cells or a complex. Best chances for isolated severe weather will reside in eastern SD and southern MN, where storm motion may prompt any cells developing in northeast SD to track into southeast ND or west central MN. Main threat with the strongest storms would be hail up to 1 inch in diameter but cannot rule out damaging wind gusts as well. As this system departs to the northeast, cloud cover will linger across the region well for much of Tuesday. The region will see potential for fog development tonight through early Tuesday morning as the boundary layer remains saturated (or nearly so) with light and variable winds in the wake of recent rainfall. This will affect high temperatures on Tuesday, but still expect slightly warmer weather than Monday with afternoon highs in the 60s to lower 70s. .LONG TERM...(Tuesday night through Monday) Issued at 348 PM CDT Mon Sep 9 2019 Late Tuesday night, chances for showers and storms develop south of US Hwy 2 as a shortwave trough aloft pushes across SD and portions of southern ND. For Wednesday through Friday, a dry interval to begin the period to be followed by increasing chances for showers/tstms during the day on Wed. This may hold off until later in the day or Wed night for a good part of the forecast area. Nevertheless, the base of a long wave trough will swing through four corners toward the central plains with closed low eventually developing over northern plains Thu. Potential for deformation zone rain increases Thu afternoon into the night, with storm totals by Fri midday likely to be in the 1.5 to 2 inch range, with the higher amounts favoring areas associated with convective activity. For Saturday through Monday, a drier period with temp recovery into the 70s with rising heights. The ECMWF offers a more zonal solution with a touch of ridging toward Mon, while the GFS is ridge free. Either way we will looking at temps trending at least toward average, if not higher. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 639 PM CDT Mon Sep 9 2019 MVFR to IFR and LIFR conditions expected the next 12 to 18 hours and possibly the entire period. CIGs and VSBY concerns with rain showers persisting into the late evening. Then drizzle or fog becomes more likely for the overnight. VSBY will improve before CIGs in the morning with MVFR CIGs expected for all sites tomorrow afternoon. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...JK SHORT TERM...BP LONG TERM...WJB AVIATION...JK