719
FXUS63 KGID 241148
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
548 AM CST Tue Dec 24 2024

.KEY MESSAGES...

- Dense fog continues through mid morning for portions of the
  forecast area. Another round of dense fog, potentially more
  widespread, expected tonight.

- Off and on drizzle and/or very light rain showers possible
  Thursday and Friday.

- Above normal temperatures persist through the end of the week,
  then boost to well-above normal levels this weekend.

- Potentially colder and more wintry pattern may arrive in time
  to ring in 2025.

&&

.DISCUSSION...
Issued at 455 AM CST Tue Dec 24 2024

Main weather impact in the short term will revolve around dense
fog. Dense fog has steadily backed into the area from the NE/E,
close to as expected thus far. Still appears that the W fringe
will stall out roughly right through the middle of the forecast
area - from just E of BBW, to near EAR, to around Superior -
within the next couple of hours. Automated obs and webcams
confirm the fog E of this line is dense and it will likely
remain so through at least 8-9AM. Wouldn`t be shocked if the
ongoing advisory needs a short 1-2, maybe 3, hour extension in
time, but will let incoming day shift assess trends and make
that determination. Weak mixing and near-minimum sun angle
argues for "slower than typical" fog erosion, esp ENE 1/3rd of
CWA. This will obviously keep those areas from warming up as
much as recent days, but W third should see more sun and a nice
warmup this aftn into the upper 40s to lower 50s.

Short-term model guidance, which has handled this AM`s activity
quite well from over 24 hrs out, suggests another round of dense
fog is likely again tonight, and quite possibly more extensive
in coverage. 06Z HRRR, in particular, is quite expansive, and
latest SREF probs for <1mi visibility is running at 60-80% for
vast majority of the CWA. Even 00Z EC gets in on the low vis
bandwagon. As such, have gone fairly aggressive with dense fog
in the grids and in the latest HWO. Would not at all be shocked
if day shift decides to issue another somewhat unusually long
lead time advisory later this aftn. Similar to today, fog will
likely linger into at least mid-AM Christmas Day - so allow for
extra time to reach your destination if heading out on the
roadways. Even after the fog erodes, expect a fair amount of
high clouds to be streaming in from the W, so any significant
sunshine seems unlikely - which will likely hamper highs in the
40s. SErly sfc winds incr a touch through the day, as well,
adding a slight wind chill. While this year will technically go
down in the history books as a "brown" Christmas, with no snow
on the ground or new snowfall, many areas may actually be
pleasantly surprised to wake up to a very frosty and winterlike
scene Christmas AM, thanks to the likely persistent freezing fog
and ice deposition on trees and other surfaces. IMO, may
actually be the best of both worlds in the sense that the visual
effect of a "white" Christmas may still transpire...but without
the significant travel impacts. Ho Ho Ho!

Expect rather gloomy conditions with perhaps more rounds of fog
to persist through the end of the week as the area remains in
fairly weak, stagnant low level flow. The annual min solar angle
of late Dec just doesn`t help mix out the low level
moisture/inversion in these types of setups. Probably going to
be at least Fri aftn, maybe even late Sat AM, before we truly
rid the entire forecast area of the low clouds and/or fog. As
for previously advertised precip chcs...latest GFS trends have
finally come around to the drier solution that EC/Canadian have
been showing for days. Continue to have several consecutive
periods of low end (20-30 percent) chances for moisture Thursday
through Friday night, but am tending to think this will be more
drizzle than organized precip, owing to the aforementioned
stagnant, primarily low level, moisture and a storm track that
is pretty far S/SE of the area.

Once we cloud the low clouds/fog, should be shaping up for
another unseasonably mild stretch that looks to coincide with
the upcoming weekend. Expect widespread 50s both Sat and Sun,
with perhaps even some low 60s in traditionally favored far W/SW
zones. Low level flow looks to have a NWrly component, but
forecast speeds remain fairly light.

Extended deterministic and their respective ensembles continue
to point towards a pattern change to colder, and potentially
more wintry around the middle of next week. This could impact
travel around the New Year`s holiday, but of course details this
far out remain vague. Pattern recognition would suggest low to
moderate type snow amounts from a clipper-like system, followed
by much colder temps in the teens and 20s, perhaps even single
digits if there is a fresh layer of snow on the ground.
Somewhere around late on the 30th into the first half of New
Year`s Eve looks to be most favored time frame for wintry
precip, but this is certainly subject to change over time.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 546 AM CST Tue Dec 24 2024

For KGRI/KEAR Airports:

Significant weather: LIFR VSBYs/CIGs through late AM, then
likely return around 04-06Z tonight.

Today: The edge of LIFR stratus and fog continues to edge
westward this morning and should overtake EAR within the next
1-2 hours. GRI is heavily entrentched within LIFR conditions and
should remain so through about 16-17Z. Thereafter, expect some
slow and gradual improvement back to VFR between 18-20Z. Winds
start off the day lgt and vrbl before bec SErly 5-8kt this aftn.
Confidence: High.

Tonight: Short term model guidance that nailed the stratus/fog
this morning suggest another round of LIFR conditions is likely
to redevelop tonight, generally in the 03-06Z time frame.
Appears this round will be more widespread, so expect both
terminals to deteriorate to LIFR around the same time. Latest
NBM probs for LIFR tonight range around 25-40%, though personal
experience and pattern recognition would suggest to me more like
60-80%. Much like this morning, conditions would be slow to
improve until at least mid to late Wed AM. Winds will be Srly
around 6-9kt. Confidence: Medium to high.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...Dense Fog Advisory until 10 AM CST this morning for NEZ039>041-
     046>049-061>064-074>077-085>087.
KS...None.

&&

$$

DISCUSSION...Thies
AVIATION...Thies