Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 170946
Area Forecast Discussion
National Weather Service Goodland KS
246 AM MST Tue Jan 17 2017
.SHORT TERM...(Today through Thursday night)
Issued at 244 AM MST Tue Jan 17 2017
Main forecast concern will be temperatures. Satellite showing a
strong zonal flow over most of the Pacific. This transitions into an
amplified and split flow over the country. The models were close at
mid levels with the Gfs doing slightly better than the rest. Models
tended to be too cool over us and to our north with the Canadian and
Gfs doing a little better.
Today/tonight...Initial question will be if any light snow will be
ongoing in Greeley and Wichita counties this morning. Mid level
sticks around through mid morning. Current radar is showing weak
returns over those counties but area has been steadily decreasing in
strength and size.
Yesterday most of the area received ice accumulation with not as
much snow. Clouds over the south will steadily decrease by late
morning. Mostly light westerly winds will be in place. Am just not
sure how much the snow will slow down the temperature recovery. At
this time what the blend gave me seems reasonable and made little to
no changes. Light west/drainage winds tonight with little to no
cloud cover will allow temperatures to fall below guidance.
Wednesday/Wednesday night...southern end of complex positively
tilted upper trough becomes cut off to the southwest during the
previous period. This system then slowly drifts to the northeast
during this period. Our area remains on the north and west sides of
this elongated circulation during this period. Soundings and plan
view relative humidity forecasts show the there will be no low level
moisture to work with. So despite being in a favorable location the
main affect of this system will be to produce clouds over the
southeast portion. Temperature guidance for this period was
reasonable and made no adjustments.
Thursday/Thursday night...Upper low continue to slowly move east.
Some model output wants to produce very light precipitation. Do not
see that happening right now due to a dry air mass in place. High
temperatures continue to warm and the forecaster builder output
looks reasonable at this time and made no changes.
For the night some model output indicating that will get strong
return of low level moisture. So at the very least stratus looks to
make a return. Not sold on any fog yet, and will wait to see what
the models show tomorrow.
.LONG TERM...(Friday through Monday)
Issued at 200 AM MST Tue Jan 17 2017
Friday-Friday night: Upper level shortwave trough is still
advertised by extended guidance to quickly move over the central
Rockies and shift over our CWA briefly deepening somewhere over the
plains. There is a considerable amount of variance on track and
timing of when this feature closes off which would drastically
change it`s impact on sensible weather over our CWA. GFS is the only
model currently that might support higher precip amounts (in our far
north Friday night) with a stronger earlier closed circulation.
ECMWF has less run-run consistency and keeps this an open wave over
our CWA (much less precip/precip potential). This is still our next
shot of measurable snow, but even the more favorable GFS keeps
majority of our CWA dry.
Saturday-Saturday night: There is a second shortwave trough that
round the Rockies and may close off over the southern plains during
these periods, however like the feature on Friday-Friday night there
really isn`t a lot of consistency between deterministic guidance,
and ensemble spread is very high. None of the advertised tracks are
particularly favorable for measurable precipitation in our CWA
except maybe our far southeast where slight chance was kept.
Sunday-Monday: Models finally show better consistency on the upper
level pattern during these periods, with shortwave ridging expected
back over the plains. This will continue to support dry conditions.
Regarding temperatures through the extended periods: Despite trough
passages Friday-Sat night and falling heights southern stream
dominates and there is very little change in air mass between weaker
cold front passages. As a result we should be near seasonal normals
(upper 30s/lower 40s for highs) until Monday when rising heights
increasing WAA may support above normal temperatures closing in on
50 once again.
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1027 PM MST Mon Jan 16 2017
VFR conditions will continue through the TAF period with mid to
high clouds diminishing overnight and only a few high clouds after
14Z. Light northwest winds will turn southwest after 20Z.