574
FXUS63 KOAX 191012
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
412 AM CST Sun Jan 19 2025

.KEY MESSAGES...

- Bitterly cold temperatures are expected to continue through
  Tuesday, with morning wind chills ranging from 15 to 30 degree
  below zero each morning.

- Temperatures warm to near-normal by Wednesday, with highs in
  the 30s, near 40 in southeast Nebraska.

- Another disturbance may bring scattered light snow showers to
  the region Wednesday evening into Thursday. Accumulating snow
  is not expected at this time.

&&

.DISCUSSION...
Issued at 400 AM CST Sun Jan 19 2025

Today through Tuesday...

Apart from a few passing clouds most of our area are under clear
skies this morning. Satellite shows clearing under the Arctic
High across the eastern Rockies and Great Plains regions. The
upper-level pattern has a large upper-level trough across the
CONUS with a sharply amplified ridge along the West Coast
stretching all the way up along the Gulf of Alaska. The ridge-
trough interface creates a broad swath of northwesterly flow
across the northern and northwestern CONUS, funneling arctic air
out of northern Canada down into our area. This is what is
causing our cold temperatures today with highs expected to only
reach into the upper single digits north to low teens south.
Northwesterly winds gusting to 20 to 30 mph this morning are
pushing wind chills down to -15 to -25 this morning. These winds
will likely hold through much of the day keeping feels-like
temperatures down below zero for our northeastern Nebraska and
west-central Iowa counties and single digits everywhere else.

Over the next couple of days we`ll see the ridge along the West
Coast start to push inland, reinforcing the northwesterly flow
keeping temperatures frigid through Tuesday morning. Subtle
shortwaves in the northwesterly flow could provide enough lift
for a few periods of flurries if we can get enough moisture, but
these will be hard to predict until we see the clouds develop.

Tuesday we see the ridge shift east, pushing the trough and this
arctic air mass off to the east. This will bring temperatures
back up into the 20s Tuesday afternoon and start the warming
trend going into midweek.

Wednesday through Saturday...

Wednesday we see another, weaker trough approach behind the
ridge moving through. This strengthens southwesterly flow,
pushing a warm front through and enhancing warm-air advection
across eastern Nebraska and western Iowa. As the warm front
moves through, some models show potential for a brief period of
flurries or light snow Wednesday morning, followed by
temperatures warming into the upper 30s to around 40 by
Wednesday afternoon before a cold front moves back through
Wednesday evening.

This is where the forecast gets more muddled as ensembles show
significant spread in the pattern behind this midweek trough.
The NBM keeps us dry Wednesday night through Thursday, but
several deterministic models suggest potential for light snow
Wednesday night through Thursday in the trailing northwesterly
flow behind the cold front. For this reason we have introduced
low PoPs for this period, but there is no signal for any sort of
significant snowfall event. This likely would only be a dusting
to an inch of snow, scattered in nature.

Going into next weekend we see a larger-scale ridge build over
our area leading to another stretch of dry weather through
Saturday. Meanwhile a couple different troughs set up along the
West Coast, setting us up with the potential for more active
weather next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 410 AM CST Sun Jan 19 2025

VFR conditions are expected to prevail. Northwesterly winds will
continue at 12-16 kts with gusts up to 25 kts possible. Winds
will calm under 12 kts Sunday afternoon. Skies will remain
mostly clear with a few clouds at FL250.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Cold Weather Advisory until noon CST Tuesday for NEZ011-012-
     015>018-030>034-042>045-050>053-065.
IA...Cold Weather Advisory until noon CST Tuesday for IAZ043-055-
     056-069-079-080.

&&

$$

DISCUSSION...McCoy
AVIATION...Wood