567
FXUS63 KFGF 092309
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
509 PM CST Sat Nov 9 2024

.KEY MESSAGES...

- Bands of light rain will continue across most of the FA
  tonight into early Sunday morning, but most areas will only
  see amounts around or less than 0.10 inches.

&&

.DISCUSSION...
Issued at 239 PM CST Sat Nov 9 2024

...Synopsis...

Water vapor imagery shows the 500mb low very nicely over
Nebraska early this afternoon. This low will track to the east
northeast tonight, but will only reach north central Iowa by
Sunday morning. A northern stream shortwave will follow quickly
on the heels of the first system, crossing southern Manitoba and
moving into Southern Ontario by Monday morning. This could
result in very light rain across the Lake of the Woods area or
it could also remain dry (the rain staying further north).
Either way, expect minimal impacts from this glancing system.

Temperatures will cool on Monday behind the passing shortwave,
before shortwave ridging brings high temperatures back to the low
50s south and upper 40s north. While high pressure departs on
Tuesday, a shortwave trough and area of low pressure develops off
the Rockies. This tightening pressure gradient between the
developing low and departing high will drive breezy to windy
conditions Tuesday afternoon. As the shortwave and attendant surface
low propagate through Tuesday night into Wednesday, precipitation
chances will return to the FA. This wave looks to be fairly open and
progressive. Both of these factors will keep rainfall amounts on the
lower side. Probabilities for 0.1" of precipitation are highest
across MN, at 40%. Values taper off quickly to the west.

Beyond midweek, deep troughing will develop over the western US,
resulting in a very amplified pattern. While this does signal the
potential for a more active period of weather, there is significant
disagreement among ensembles about the details. The most important
and consistent takeaway at this point is the warm temperatures that
will be in place. All clusters show 850 mb temperatures of 1-3
degrees C over the weekend, with the 540DM heights well north and
west of the forecast area. Definitely something you do not see often
when forecasting in mid November.

...Rain tonight into Sunday morning...

Not much rainfall has accumulated so far today, with most
sensors only showing a trace to 0.01 inches. Cloud bases have
remained high, generally 8,000 to 10,000 feet. The dry sub-
layers shown in the morning upper air soundings have prevented
much of the rain from reaching the ground (a lot of virga). The
forcing with this system remains very weak and not very focused.
Therefore moving into tonight, think these weak bands will
continue, but not remain over any one area very long. The latest
guidance is showing some stratus and fog developing over
portions of the area late tonight into Sunday morning as well.
At this point, that looks more likely over far southeast North
Dakota into adjacent areas of west central Minnesota, possibly
as far north as Bemidji. Went ahead and blended to adjacent
offices with the mention of fog in these areas.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 507 PM CST Sat Nov 9 2024

Rain and low ceilings will continue to be the aviation impacts
of the TAF period. Ceilings will continue to fall this evening
to MVFR and IFR, especially the further south you go. There is
the low potential for fog to develop after 06z, but confidence
is low in how significant fog will be for flight category
impacts.

&&

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

&&

$$

DISCUSSION...Godon/Rafferty
AVIATION...Perroux