419 
FXUS63 KOAX 142328
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
528 PM CST Sun Feb 14 2021

...Updated Aviation Forecast Discussion...

.DISCUSSION...
Issued at 330 PM CST Sun Feb 14 2021

The main forecast concerns are in regards to the cold temperatures 
and bitter wind chills. 

Will cancel part of the Winter Weather Advisory a little early but 
let four counties remain in the Advisory until 6 pm near the KS 
and MO border. Some snow will linger down in that area for a while
into early evening. There were some pockets of over 3 inches of 
snow from last night into today in the Advisory.

The large scale pattern had the primary features of interest. At 
300 mb there was a strong jet from the northwest punching into WA
and OR, then that was diving southward to near the AZ/CA border. 
There were a few segments with speeds of 140-160 knots. Another 
jet segment extended from upper MI northeastward. At 500 mb, the 
cold pocket associated with the low over southwest Ontario was 
at -45 C. The cold pocket at 850 mb was roughly in the same area 
and was about -34C, yikes. There was a decent piece of energy in 
the southern stream of the split flow, with height falls of near 
150 meters in southern AZ. Energy associated with that will stay 
to our south. An area of cold high pressure at the surface was 
centered over the border area of SD/ND/MN at about 1043 mb, but 
the high stretched from southern Canada down into TX. 

Fortunately the coldest air at 850 mb will stay to our northeast, 
but with a lot of snow on the ground, temperatures will plummet with 
light winds and areas of clear skies or just scattered clouds. Winds 
today were a bit stronger than expected, but in general we do not 
expect winds to be as strong the next few days. That will help with 
wind chills, especially with some slight warming of air temperatures 
during the late morning to mid afternoon. A Wind Chill Warning 
will be in effect from tonight through Tuesday morning, but we 
should see improvement during the day Monday. The coldest values 
should be from about 9 pm to 11 am tonight/Monday morning and then
again Monday night into Tuesday morning. Air temperatures will 
probably only peak at zero or below Monday and then drop into the 
-18 to -23 range for most locations in eastern NE and southwest IA
Monday night. 

Temperatures will slowly moderate through the week, as the mid 
tropospheric flow pattern deamplifies and becomes more zonal. We 
expect highs from -3 to +4 Tuesday, 9 to 14 Wednesday, 12 to 20 
Wednesday, 20 to 30 Friday, 29 to 36 Saturday and in the 30s all 
areas by Sunday.

Overall precipitation chances look fairly low, but will include a 
small chance for light snow or snow flurries for at least parts of 
the area from Tuesday night into Wednesday. There is also some 
chance for precipitation next weekend, but model agreement is poor 
at this time. 

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 526 PM CST Sun Feb 14 2021

VFR conditions expected this TAF period. Existing clouds will be
above 9,000 ft, or higher with northerly winds. Clouds should
diminish from northwest to southeast through the night.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Chill Warning until noon CST Tuesday for NEZ011-012-015>018-
     030>034-042>045-051>053-067.

     Winter Weather Advisory until 6 PM CST this evening for 
     NEZ090>093.

     Wind Chill Warning until noon CST Tuesday for NEZ050-065-066-068-
     078-088>093.

     Wind Chill Advisory until 6 PM CST this evening for NEZ050-065-
     066-068-078-088>093.

IA...Wind Chill Warning until noon CST Tuesday for IAZ043-055-056-069-
     079-080-090-091.

&&

$$

DISCUSSION...Miller
AVIATION...Pearson