503 FXUS63 KFGF 131138 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 538 AM CST Mon Jan 13 2020 .SHORT TERM...(Today through Tuesday) Issued at 321 AM CST Mon Jan 13 2020 Early morning water vapor imagery shows broad troughing over the western two-thirds of the CONUS with southwesterly flow over the northern Plains. Two embedded shortwaves are noted with the first located across the western half of SD and the second further upstream across northern ID. A thermal ridge in place across the eastern Dakotas and southern Manitoba per recent RAP analyses is the result of mid level warm advection ahead of the first shortwave. This warm advection is also responsible for the scattered flurries and light snow showers ongoing this morning. These flurries and light snow showers will continue across central ND (including the Devils Lake basin) through mid day as the wave approaches. At the surface, a surface low associated with the first shortwave was noted across western SD with an inverted trough axis running through central ND. Modest moisture advection towards the trough axis and into a relatively cooler airmass is resulting in pockets of fog across central ND with visibilities between 1-3 miles. This fog should continue through sunrise with periodic reductions in visibility below one mile possible. Locations that will most likely see fog include areas surrounding Devils Lake, Cooperstown, Valley City, and Lisbon. Nocturnal cloud cover will help maintain fairly warm temperatures through sunrise, and continued low level warm advection will help temperatures climb into the upper teens and 20s for most of the region. Snow chances return later tonight as the second wave begins to approach the region. Snow is most likely across two regions: north central ND and across central and northwest MN. Southeast ND may see flurries at times tonight, but likely won't see any accumulating snowfall. Snowfall associated with deformation on the backside of the mid level wave is expected to begin across northern ND this evening and will most likely bring low-end snow amounts between 0.5-1.5 inches. A reasonable worst case scenario is that a more organized deformation band could bring slightly higher amounts, but this potential appears to be very low based on recent ensemble CAM guidance. As for northern/northwest Minnesota, snowfall will begin well after dark - most likely after midnight tonight as the zone of warm advection shifts eastward and is augmented by synoptic ascent associated with the approach of the wave. Snowfall amounts are generally expected to increase from the Red River Valley (around 0.5 inch) eastward towards the Bemidji/Baudette region (around 2.0 inches likely). Ensemble guidance does show the potential for banding to bring locally higher amounts up to 3-4 inches across north central MN, but confidence in these higher amounts is low. Snow may linger into Tuesday morning across northern MN, but will exit the region by the afternoon hours. A cold front associated with this system will bring colder temperatures for Tuesday with highs only reaching the single digits to teens. .LONG TERM...(Tuesday night through Sunday) Issued at 321 AM CST Mon Jan 13 2020 Active pattern brings snow chances and cold air plunges as the main impacts. Tuesday night through Thursday...A shortwave trough coming over the top of the ridge will bring another chance for snow shortly after the last, mainly to more southwestern portions of our CWA. The NAM has quite a bit of 850mb frontogenesis with the synoptic lift, and drops quite a bit of QPF Tuesday night. While banding potential is definitely possible, the system is very fast moving, with high pressure starting to move in by Wednesday. M- climate QPF percentiles are also not too impressive for the period. Think a quick few inches will be possible Tuesday night/Wednesday morning. This will be followed by very cold air with Arctic high pressure building in for Thursday. Morning lows could get down to 20 below or lower, although rising heights later in the day should allow readings to get closer to the zero mark. Friday...There is consensus on a fairly vigorous upper trough moving into the Dakotas, although with the deterministic models the surface features are all over the place. R-climate and M-climate percentiles have highest humidity and QPF values mostly to our southeast, but some 99th percentiles into our eastern counties. Think that chances of snow will be high which is reflected in the NBM, but a question of how much moisture return makes it this far north and therefore how much snow. Will continue to monitor for any stronger signals as the system gets closer in time. Saturday and Sunday...The upper trough moves off into the Great Lakes, leaving northwest flow aloft and another cold surge in its wake. There are signs of a weak clipper for Sunday, but placement is inconsistent and may not get more than a few flurries, so kept POPs minimal for the moment. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 524 AM CST Mon Jan 13 2020 MVFR conditions this morning (with the exception of KDVL, which is experiencing IFR ceilings) are expected to gradually deteriorate to IFR, and at times LIFR conditions, through the day and into tonight as light snow moves through. This morning, ceilings between 1-2 kft are predominant across far eastern ND and northwest MN. Across central ND a deck of lower stratus with ceilings between 300-500 feet is gradually shifting north and east. Patchy fog is associated with this stratus deck with a few obs sites reporting visibility reductions down to 1-2 miles. While the IFR cigs are impacting KDVL, visibility reductions from fog can't be ruled out this morning. Additionally, scattered flurries and light snow showers are moving across the region and may bring brief periods of snow to any terminal this morning. Little to no snow accumulation is expected with this activity. Heading into tonight, light snow will overspread northeast ND between 00-12Z with light accumulations (one inch or less). This snow will likely impact KDVL and KGFK. Between 06-12Z snowfall will begin spreading into northwest MN and will impact KTVF and KBJI. One to two inches of snow accumulation will be possible, especially for KBJI. KFAR may see brief light snow tonight, but confidence on snow occurrence is low. During this period IFR conditions, and periods of LIFR conditions concurrent with snowfall, are expected. Conditions will gradually improve Tuesday morning after 12Z from southwest to northeast. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ SHORT TERM...AM LONG TERM...JR AVIATION...AM