844 
FXUS63 KFGF 200037
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
637 PM CST Thu Dec 19 2019

.UPDATE...
Issued at 637 PM CST Thu Dec 19 2019

Fairly quiet for the moment with just some high clouds covering
spotty stratus. Made a few minor tweaks to temperatures, but not
any huge changes. Still looking like better low level moisture
will move in after midnight, with fog developing mainly in eastern
ND. Will continue to keep low chance for some flurries or light
freezing drizzle across west central MN towards morning with the
shortwave lifting through. 

&&

.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 00Z TAFS through 00Z Friday evening)
Issued at 539 PM CST Thu Dec 19 2019

Some IFR ceilings hanging around KBJI, but other TAF sites have
gone VFR for the moment with high clouds. Best conditions will be
for a short time this evening before MVFR then IFR ceilings move
back into all TAF sites later tonight. Some fog will be possible
in eastern ND, so have KDVL going down to 1-2SM. Flurries and
freezing drizzle will be possible in west central MN, but at this
point think it will stay southeast of the TAF sites. The lower
ceilings will continue for a large portion of the day Friday, 
with only some improvement to MVFR or VFR by afternoon. Winds from
the east and northeast at 10 to 15 kts this evening will become
light and variable overnight into tomorrow. 


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

$$

UPDATE...JR
SHORT TERM...BP
LONG TERM...NC
AVIATION...JR