510 
FXUS63 KOAX 311712
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1112 AM CST Tue Jan 31 2023

...Updated Aviation Forecast Discussion...

.DISCUSSION...
Issued at 218 AM CST Tue Jan 31 2023

Key Messages:

- Potentially hazardous wind chills of -15 to -25 degrees in
  northeast Nebraska and western Iowa this morning. 

- Another round potentially hazardous wind chills may (20% chance)
  occur Friday Morning in northeast Nebraska.

- Above average temperatures return this weekend.

At 218 AM, a narrow band of high cloud cover stretched along 
Interstate 80 from Omaha to Denver. Otherwise skies were clear. 
Surface temperatures ranged from -5 to 5 degrees with the coldest 
values occurring over the snowpack in northeast Nebraska. 
Southwesterly winds were producing wind chills of -5 to -25 
degrees north of Interstate 80. These conditions should remain 
relatively steady through sunrise.

Today and Tonight: 

The axis of a weak upper level trough will slide east from WY/CO 
today. Lift and moisture ahead of this feature should continue to 
generate patchy high cloud cover through this morning. A couple 
radar echos may show up this morning, but a stout dry layer in the
lowest 400 mb of the atmosphere will keep us precip free. At the 
surface, southwesterly winds (5 to 15 mph) will prevail as high 
pressure slides to the southeast. The southwesterly winds will 
combine with low temperatures in the -5 to 5 degree range to 
produce biting wind chills this morning. The coldest wind chills 
(-5 to -25 degrees) are expected north of Interstate 80, and a 
Wind Chill Advisory remains in place for portions of northeast 
Nebraska and northwest Iowa through 9 AM. Lighter winds and 
slightly warmer temperatures will keep the wind chills more 
reasonable in the Metros (Lincoln and Omaha) and southeast 
Nebraska. Expect wind chills of 0 to -10 degrees in these regions 
through 9 AM.

As the day progress temperatures will moderate as southwesterly 
winds (WAA) and increasing sunshine do their thing. By this 
afternoon most of the region should break the 20 degree mark for the 
first time since early Saturday morning. In parts of northeast 
Nebraska a deeper snow pack may limit any warming to the upper 
teens. Fair skies should result in strong radiational cooling 
tonight, allowing temperatures to crash back into the single digits 
despite persistent southwesterly winds. 

The Rest of the Workweek:

The remainder of the workweek will be defined by an upper level
trough traversing the southern tier of the U.S (from SoCal to the
Southeast) and a gradually building ridge over the Western U.S. 
The upper level trough passing to our south should generate 
widespread precipitation, unfortunately it will stay well south of
Iowa and Nebraska. The ridge out West will bring gradually 
increasing 500 mb heights. It will also set us up for frontal 
passage and resultant punch of cold air Thursday and Friday as a 
weak trough slides along the Canadian Border. This round of colder
air doesn't look as strong as what occurred over the weekend. 
Right now ensemble guidance suggests a 20% chance of
-20 degree wind chills in northeast Nebraska Friday morning. 

Dry weather is all but guaranteed through Friday. Of the 80 GEFS 
and EPS ensemble members, none indicate even a trace of 
precipitation between Wednesday and Friday. 

Noticeably Warmer this Weekend:

Ensemble mean guidance from the EPS, GEFS and CMCE all shift the  
Western ridge towards the Plains over the weekend. This should 
combine with downsloping flow in the lee of the Rockies to produce
a rapid transition to above average temperatures Saturday and
Sunday. The majority of EPS members suggest highs in the mid 40s
on both Saturday and Sunday. GEFS guidance is a bit more 
pessimistic for Saturday with highs in the upper 30s, but it brings
in mid 40s for Sunday. Forecaster confidence in high temperatures
reaching the 40s is high for Sunday (>80%), and moderate for 
Saturday (60%). Northeast Nebraska may be the lone area excluded 
from the 40 degree highs this weekend due to the deep snowpack. 
Dry weather is likely through the weekend (>95% chance), with only
3 of the 80 GEFS/EPS members indicating even a trace of 
precipitation.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1109 AM CST Tue Jan 31 2023

VFR conditions are expected through this TAF cycle with mostly
clear skies and southwest surface winds generally less than 12kts. 

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&

$$

DISCUSSION...Albright
AVIATION...Kern