031
FXUS63 KFGF 231250
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
650 AM CST Mon Dec 23 2024

.KEY MESSAGES...

- Fog may be prevelent for an extended period this week,
  especially in northeast ND.

- As we gradually warm up, next system moves up Friday and gives
  majority light rain. But will need to monitor surface temps
  closely.

&&

.UPDATE...
Issued at 648 AM CST Mon Dec 23 2024

Thicker fog expanding southward into Valley City in the hour. So
extended dense fog adv into Barnes county and Griggs county as
BIS updated fog adv as well to go south. Otherwise cloudy sky
with low clouds having covered all but far southeast fcst area.
The light snow in the Fergus Falls and Elbow Lake area with the
upper wave moved out by 1230 UTC.


&&

.DISCUSSION...
Issued at 337 AM CST Mon Dec 23 2024

...Synopsis...

We transition to a west-southwest to more south-southwest flow
at 500 mb this week. This will lead to increasing warmth thru
the week, peaking Friday. System moving north-northeast in the
flow will move through giving a chance of precipitation, with
indications are to be rain. But will need to monitor temp
guidance.


...This Week...

Short wave which brought the icing issues to northwest into
central is moving out. A bit of freezing drizzle did sneak into
far SE ND midnight-2 am but has since turned to light snow and
is moving out. Light snow patches in WC MN as well. Atmospheric
column is cooling this morning as colder air moves south.

High pressure will move east thru Southern Manitoba and into NW
Ontario by this evening. Weak north sfc flow with this but
soundings show a lot of low level moisture. Thus trended
cloudier than NBM and other guidance shows for clouds. I did
keep some chance of scattered clearing in NW MN today mainly for
collaboration purposes but looking upstream all I see is
clouds. Fog....some dense is in northeast ND and has been
spreading south, particularly in areas from Cavalier and Langdon
to Devils Lake and New Rockford where webcams and AWOS data
shows dense fog is widespread. Coord with BIS and have dense fog
adv thru noon this area. Did keep mention of fog most of E ND
and RRV thru the day....but as usual uncertainity exists in
this. Could well be socked in all day esp in DVL basin.
Question of freezing drizzle. Discussed with BIS and looks like
sounding while supports the clouds and fog with light winds in
the inversion up thru 900 mb unsure if there is any lift in this
layer or above for any drizzle. So for this reason kept drizzle
out of the fcst. Did mention in NPW though ice crystals may
deposit on surfaces causing them to be slick.

For the week as we gradually warm up....clouds and fog chances
may well linger every day.

For Friday...ensembles paint a higher chance for light rain to
move north into the area during the day. GFS and ensembles a bit
heavier with precip (0.15 GEFS mean) vs ECMWF/Canadian Global.
But if low level temps remain as they are forecast will be warm
enough for rain as temps above freezing during the majority if
not all of the precip time. But this will need to be monitored
in the coming days. Also road temps too they should rise some as
temps moderate but may be close.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 538 AM CST Mon Dec 23 2024

IFR conditions due to ceilings or visibility for most areas
today into tonight. Tried to give some rise in ceilings this
aftn or evening, but high uncertainity in that. Soundings show
low level moisture hanging around. Light north winds today under
10 kts, near calm this evening and then turning south later
tonight.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Dense Fog Advisory until noon CST today for NDZ006>008-014>016-
     024-026-054.
     Dense Fog Advisory until noon CST today for NDZ028-038.
MN...Dense Fog Advisory until noon CST today for MNZ004-007.

&&

$$

UPDATE...Riddle
DISCUSSION...Riddle
AVIATION...Riddle