996 FXUS63 KFGF 192100 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 300 PM CST Thu Dec 19 2019 .SHORT TERM...(This evening through Friday night) Issued at 257 PM CST Thu Dec 19 2019 Minor impacts possible tonight through early Friday as fog and flurries/light snow and freezing drizzle develop across portions of the region. Split flow aloft across the central U.S. puts the Northern Plains under a drier airmass with a progressive trough aloft moving east through the region through Friday. Strong mid level warm air advection develops tonight ahead of this upper trough and a weak surface low progressing through SD toward eastern MN, prompting fog development. Latest guidance suggests the best chance for fog is across eastern ND tonight with potential for additional fog development over west central and northwest MN Friday morning. Additionally WAA will bring potential for light precipitation late tonight and Friday morning with the highest chance for west central MN, in closer proximity to the sfc low. Flurries or light snow will continue to remain possible with this activity, but there is an additional complication in that model soundings indicate that warmer, drier mid level air building into west central MN. This would prevent or dissipate ice nuclei aloft, which would result in potential for freezing drizzle as well. Best chance for this to occur looks to be Friday morning over west central MN. Increasing cloud cover and WAA tonight will not allow for much nocturnal cooling overnight, keeping low temperatures in the single digits to teens above zero. Continued WAA and upper level ridging building into the region heading into Friday night will bring continued warming. Expect high temperatures on Friday to reach the 20s for most sites, but with lesser certainty in MN due to lower confidence in daytime cloud cover. .LONG TERM...(Saturday through Thursday) Issued at 257 PM CST Thu Dec 19 2019 Ridging aloft will dominate the synoptic pattern this weekend into early next week with near to above average temperatures expected. The warmest temperatures will be over the weekend when NAEFS, ENS, and GEFS M-Climate Percentiles have 850 mb and 700 mb temperatures in the 99th percentile. This will help lead to warmer than normal temperatures in the 30s, but warmer near record temperatures are not expected at this time as the warmest air is not expected to mix down to the surface. An area of uncertainty with this weekend is how much moisture could be available as some ensemble and deterministic solutions suggest more moisture which could produce some freezing drizzle with the anomalously warm air aloft. Most ensemble and deterministic solutions are dryer though which suggests that freezing drizzle is possible, but not likely at this point. The upper ridge begins to move out on Monday bringing an end to the warmer temperatures and a return to near average temperatures by Christmas Day. By Christmas Day a transition to southwest flow aloft will provide for a more active pattern that could provide some snow across the Northern Plains. Ensemble solutions still vary greatly for this period so details remain uncertain. At this point the most likely forecast would be for light snow, but some ensemble members do suggest higher totals so this cannot be ruled out yet. Timing, QPF, snow amount will become clearer as we get into next week. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1141 AM CST Thu Dec 19 2019 A difficult forecast today with scattered IFR ceilings and flurries along and north of a line from KDVL to KGFK to KBJI. Expect IFR ceilings to occur more often than not through this afternoon, but hedged toward a more optimistic VFR ceilings for KGFK, KTVF, and KBJI by this evening. Expect patchy fog and IFR ceilings to prevail at KDVL tonight and for ceilings to deteriorate west to east to IFR by early Friday morning. The longest lasting IFR conditions, including potential for freezing drizzle, are expected to linger in the vicinity of KBJI and KTVF for much of Friday. Generally expect light and variable winds through tonight, becoming easterly and remaining mostly under 10 kts through the TAF period. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ SHORT TERM...BP LONG TERM...NC AVIATION...BP