228
FXUS63 KOAX 121418
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
818 AM CST Wed Feb 12 2025

.KEY MESSAGES...

- The chances for 4+" and 6+" storm-total snow in the Winter
  Storm Warning area are 70-90% and 40-70%, respectively. Peak
  snow rates of 0.5-1"/hour are expected from through 9 AM this
  morning, making the morning commute difficult for many.

- Snow consistency will be powdery and easy to move, but some
  areas of blowing snow could develop this afternoon as north
  winds increase with gusts of 20-25 mph.

- Air temperatures fall below zero tonight into Thursday morning
  with minimum wind chills of -15 to -25 forecast.

- There is another chance (40-60%) for snow Friday into
  Saturday.

- Another dangerously cold morning is possible Sunday.

&&

.DISCUSSION...
Issued at 400 AM CST Wed Feb 12 2025

Today:

Water vapor imagery this morning features a shortwave trough placed
across the High Pains that drives the current snow area-wide, with
clouds in that imagery exhibiting a good amount of texture on top
indicative of somewhat convectively-driven, increased snowfall.
Taking a look at road cameras across the area, a good chunk of the
area has already seen 1-2 inches of snow as of 3 AM, with areas in
the southwestern forecast area starting to get closer to 3 inches.
We still have plenty of work to do in order to make the snowfall
forecast. Other than the snow, cold temperatures continue
alongside steady winds that add an extra bite to the air -- to
the tune of wind chills in the 5 to 15 below range.

Taking a closer look at the snowfall, we are the boom or bust point
for snowfall. The more textured cloud tops on satellite coincide
with marginal CSI and elevated instability ahead of the strongest
500 mb support, which is oriented from the Texas Panhandle north-
northeast towards central Nebraska. As it continues to pivot and
push eastward, it`ll continue to help the slight convective and
symmetric instability rooted at the 500-600 mb range give us our
healthiest snowfall so far. The main forcing is still rooted above
the main isothermal layer, but despite that, we`ve still enjoyed
reports of around 15:1 to over 20:1 snow-to-liquid ratios --
a good sign if we are going to verify this forecast.

As we progress through the morning, expect the snowfall to continue
its consistent pace through around 7 AM, where the HREF CAM ensemble
loses its best snowfall rates of 0.5" per hour or more. The snowfall
should then continue carrying on through the morning at less than
0.25" per hour, before tapering off more aggressively by 6 PM. Wind
speeds will remain steady across the area alongside an occasional
gust to 20 mph, with slightly stronger winds gusting to around 25
mph in southeast Nebraska. These blowing winds will drift and lead
to some reduced visibility due to its fluffy character, leading
to some lingering visibility restrictions after the snowfall
has ended. Totaling up the remaining snowfall from 6 AM onward,
the current expectation is that the forecast area would receive
another 1 to 4 inches, with the highest amounts being in western
Iowa and the lowest being in northeast Nebraska. The slow burn
of this snow system is somewhat dissatisfying, but it should add
up over the course of the day.

Thursday and and Beyond:

On the heels of the winter system, cold temperatures and enough
breeze will kick the day off with wind chill values in the 15 to 25
degree below zero range. With that said, a Cold Weather Advisory has
been issued for all of the forecast area aside from far southeast
Nebraska. One particular note to make with the cold is that the
chances for folks to get in a wreck or slide off the road is much
higher than normal thanks to the slick conditions. For the rest of
the day, highs only reach the upper teens to low twenties providing
little relief from the cold before we plunge back down into the
single digits overnight.

We`re still tracking another shot at snow Friday/Saturday where a
positively-tilted shortwave through ejects from the western CONUS.
The orientation of the jet/vort stream leaves the stronger advection
less effective as it pivots out, making an early glance a snow
totals with this round of a trace in northeast Nebraska to 2 or 3
inches in southeast Nebraska -- squarely in the conversational snow
side of things for the majority of the Omaha and Lincoln Metro
areas. There is a second scenario that we could see the latter half
turn to areas of drizzle as we lose dendrites, but we`ll get more in
to the details of that system as we approach the end of the week.

Sunday through the end of the forecast looks mostly dry with another
strong cold punch that could necessitate some action for the
morning hours wind chill wise. The upcoming work week forecast
looks to continue the relatively active pattern with a clipper
system or two possible next week, though there are plenty of
cogs to turn before we get there.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 537 AM CST Wed Feb 12 2025

Snow continues at all TAF sites through at least 21Z, and likely
for a few hours longer. IFR conditions will be prevalent with
the snow, but there may be periods of LIFR visibility with
heavier snow bands, particularly at LNK and OMA. After the snow
ends, expect ceilings to improve to VFR through the remainder of
the TAF period.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Winter Weather Advisory until 6 PM CST this evening for NEZ011-
     012-015>018-030>034-042>045-050-051-065.
     Cold Weather Advisory from 11 PM this evening to 9 AM CST
     Thursday for NEZ011-012-015>018-030>034-042>045-050>053-
     065>068-078-088>090.
     Winter Storm Warning until 6 PM CST this evening for NEZ052-
     053-066>068-078-088>093.
IA...Winter Weather Advisory until 6 PM CST this evening for IAZ043-
     055-056.
     Cold Weather Advisory from 11 PM this evening to 9 AM CST
     Thursday for IAZ043-055-056-069-079-080-090-091.
     Winter Storm Warning until 6 PM CST this evening for IAZ069-
     079-080-090-091.

&&

$$

DISCUSSION...Petersen
AVIATION...Barjenbruch