804 
FXUS63 KOAX 130536
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1136 PM CST Wed Feb 12 2020

...Updated Aviation Forecast Discussion...

.DISCUSSION...
Issued at 250 PM CST Wed Feb 12 2020

Tonight and Thursday

Main forecast problem tonight into early Thursday is the arrival 
of the arctic front, combined with rain changing to snow through
late evening, then bitter cold temperatures with wind chills 15 to
30 below tonight.

Arctic front at 20z was just north of a line from Columbus to
Sioux City. Scattered rain/snow showers have develp along ahead of
the front, in fact we're getting reports with all snow with temps
as high as 39/40 degrees. Certainly cold enough aloft, and precip
type was dependent on the temps in the lowest 1500 feet. Winds
gusting up to 40 mph along behind the front, with sharply colder
temperatures quickly moving in. Yankton has already dropped to 
12, and Oneill down to 17. Albion down to 21, and Wayne down to
23. There has been some concern if there would be enough 
precipitation to make the roads wet, with the flash freeze 
expected to create icy conditions along I80, and for the metro 
areas during the evening rush hour. At this time, we have opted to
hold off with any type of winter weather advisory, but will see 
how this continues to develop in the next hour or two. Winter
weather advisory for northeast NE will continue until 6 pm, but
little measurable snow has fallen there today. 

Lows tonight drop to 0 to 10 below, and when combined with the
strong winds, will create wind chills from 20 to 30 below zero.
Thus, the wind chill advisories that were previously issued for
tonight through Thursday morning look good. The coldest values
around -30 are for northeast NE and northwest IA, and may have to
consider upgrading a handfull of counties to a wind chill warning. 
Still quite cold Thursday with highs in the single digits and 
teens but with northwest winds diminishing.

Friday through Sunday

Fortunately the arctic blast is short lived and temperatures
progressively warm each day, eventually reaching the upper 40s and
lower 50s by Sunday. There is a weak wave moving through the
region Saturday, and there could be some precip east of the
region, but otherwise, it looks like a dry weekend. 

Monday through Wednesday

Models are suggesting the next trough could be impacting the
region Wednesday with a chance of rain changing to snow. The EC is
more aggressive with the precipitation than the GFS, so there
still are some model discrepancies to deal with, but model blends
still suggest at least a chance of precipitation. Weather looks
dry for Wednesday. 

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1132 PM CST Wed Feb 12 2020

VFR conditions are expected with bitterly cold wind chills. Gusty
northwest surface wind to 35kts are expected through the overnight
and will gradually subside by late Thursday morning and through
the afternoon to eventually light and variable by 00z and
thereafter.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Chill Advisory until 11 AM CST Thursday for NEZ011-012-
     015>018-030>034-042>045.

     Wind Chill Advisory until 9 AM CST Thursday for NEZ078-088>093.

     Wind Chill Advisory until 9 AM CST Thursday for NEZ050>053-
     065>068.

IA...Wind Chill Advisory until 11 AM CST Thursday for IAZ043-055-056.

     Wind Chill Advisory until 9 AM CST Thursday for IAZ069-079-080-
     090-091.

&&

$$

DISCUSSION...DeWald
AVIATION...Kern