105 
FXUS63 KGID 180940
AFDGID

AREA FORECAST DISCUSSION
National Weather Service Hastings NE
340 AM CST Tue Feb 18 2020

.SHORT TERM...(Today and tonight)
Issued at 327 AM CST Tue Feb 18 2020

Today's weather is shaping up to be dry and pretty seasonal 
temperature wise ahead of an approaching upper trough and cold front 
which will bring a return to colder/wintry conditions heading into 
Wednesday. 

Morning cloud cover will be decrease leading to a fair amount of 
insolation for the daytime period and temperatures should be 
right around where they are expected to be this time of 
year...near 40F or in the low 40s. We'll also see a reprieve from
gusty winds under the influence of a surface ridge.

The weather pattern will undergo changes tonight/Wednesday as an 
upper trough across the interior Canadian provinces deepens into the 
northern and central CONUS, sending a surge of cold air south into 
our region and returning chances for snow to our area heading into 
Wednesday.

.LONG TERM...(Wednesday through Monday)
Issued at 327 AM CST Tue Feb 18 2020

The main weather focus this week centers around the Wednesday time 
frame when we see increasing chances for snow and the potential for 
snow accumulations.

Snow is expected to develop toward daybreak Wednesday morning across 
portions of western and northern Nebraska in presence of good 
dynamics with increasing isentropic lift ahead of an approaching 
upper trough translating southeast from the northern Rockies/North
Plains, with lift also enhanced in an upslope flow regime and 
presence of strong mid level frontogenesis in the H85-H7 layer. 
Forecast models are in decent agreement that a band of heavier 
snowfall should set up across portions central/north central 
Nebraska, perhaps extending to the southwest into SW Neb. The 
narrow nature of frontogenetic snowbands are difficult to pinpoint
and at this time the NAM is the most aggressive of the models 
with a snow band and orients it across our far northern counties 
(Ord/Greeley areas) with potential amounts in excess of 6 
inches. The NAM also extends that snow band to the southwest 
toward SW Neb but with lower amounts (to the SW). The GFS also 
favors a snow band across central/northern Neb but with amounts
not quite as high and more so in the 2-4" range...and the ECMWF 
suggests similar amounts of roughly 1-4" with the higher amounts 
north of our cwa. While locally heavier snow amounts are likely 
within snow bands, overall the NAM is looking too aggressive attm 
compared to other models with its prolonged frontogenetic band 
and feel system will be more progressive and have kept our
forecast snowfall conservative vs worst case scenario.

So the snow which develops to our west and north early Wednesday 
will spread south and east across our local area through the day,
favoring a daytime/evening event before moving out Wednesday 
night. Given model differences in snow band placement and totals, 
have followed closer to ensembles with snow amounts of roughly 1-3
inches along/north of a Lexington to Greeley line, with amounts 
of roughly an inch or less elsewhere...but be sure to stay up to 
date with latest forecasts and model trends. If snow amounts trend
up, we may end up needing a winter weather headline. This snow 
event will be of the drier/fluffy type in the post frontal colder 
airmass with snow ratios of generally 15:1 to 17:1. Winds won't 
be overly strong, but not calm either in the 10-20 mph range.

A cold night is in store for our area Wednesday night as a 1048mb 
surface high builds south along the MO River. Temps are forecast to 
plummet to the single digits/teens for lows with wind chills also in 
the single digits.

Thursday will be the transition day between the departing cold air 
to the east and warmer air to the west. Friday will start to see a 
better temperature recovery with readings returning closer to 
normal, but southerly winds are looking strong/gusty so it may not
feel quite as pleasant. 

Have not deviated from the model ensembles over the weekend with 
temps near/above normal. The pattern does become active again with a 
system crossing the southern portion of our region around the Sunday 
time frame, and this system is expected to be followed by another
potential system heading into Tuesday...so we could see more 
moisture around in the outer periods.

&&

.AVIATION...(For the 06Z KGRI/KEAR TAFS through 06Z Wednesday)
Issued at 1106 PM CST Mon Feb 17 2020

MVFR clouds earlier this evening have begun to scatter and move 
south of the terminals and therefore have just maintained some of
these scattered clouds for a few hours. Otherwise the remainder 
of the night should see some mid/high level clouds before 
decreasing during the day Tuesday. Northerly wind speeds have 
dropped off as surface high pressure builds onto the Central 
Plains and look for winds to be fairly light heading into Tuesday
under the influence of the sfc ridge before transitioning
southeast/southerly toward the latter TAF hours as the ridge 
migrates east.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.

&&

$$

SHORT TERM...Fay
LONG TERM...Fay
AVIATION...Fay