FXUS63 KGLD 190959

Area Forecast Discussion
National Weather Service Goodland KS
359 AM MDT Thu Sep 19 2019

.SHORT TERM...(Today through Saturday night)
Issued at 357 AM MDT Thu Sep 19 2019

Forecast concerns will be rainfall chances into Saturday, chance of
severe/locally heavy rainfall through Friday night, and very strong
winds on Friday. Satellite showing an increasingly amplified pattern
from the Pacific into the western Atlantic.

Today/tonight...Earlier in the night, elevated storms did develop
over the northwest portion of the area due to warm air advection,
weak shortwave trough, and weak right rear quadrant of upper jet.
There looks to be a consensus of the high resolution guidance to
produce some fog through mid morning. Dewpoint depressions are
narrow so will have some fog through 15z.

Shortwave trough and northern stream jet pull off to the north by
late morning. Late in the afternoon the left front quadrant of a
southern stream jet starts approaching the southwest portion of the
area. This left front quadrant lifts further north during the night
and affects the southern half of the area by late in the night.

A shortwave trough moves across most of the area later in the
afternoon into the overnight hours. Surface trough is a little
further west than yesterday with a dryline looking to setup near the
Colorado border. High resolution/CAMs remain consistent, even more
so than yesterday, in producing storms along and west of the
Colorado, with the greatest concentration in the southern portion
of the area.

So raised pops slightly. Models are in better agreement with
precipitable water values of 1 to 1.5 inches. With southerly flow
aloft, training looks like a possibility. So locally heavy rainfall
looks to be a real threat, and raised the qpf a little although it
probably could be raised a little more. WPC now has the area in a
marginal risk for excessive rainfall, and that is definitely

SPC has area along and east of the Colorado border in a marginal
risk for severe weather. Effective shear looks to be 20 to 30 which
is what it was yesterday. Dcape is near 1000. So damaging winds look
to be the main threat, but would consider the heavy rainfall the
main threat.

Friday/Friday night...Still a lot of uncertainty with this period.
The chances for thunderstorms and severe weather will be influenced
by the mesoscale affects of todays convection. Plus models are not
as consistent/cohesive on the timing/location of thunderstorm
development. At face value the models actually look like they do not
have as great of a chance of rainfall as they do today.

Left front quadrant/jet axis develops/moves over the northwest half
of the area during the afternoon, and then slowly moves across the
area during the night. Storms that develop will be much more able to
become severe than todays activity due to the stronger flow aloft
combined with the very strong south to southeast flow at low levels.
This will be in advance of a cold front that will move through
during the night. Left the forecast blend pops alone.

SPC still has area in a marginal risk which looks fine for now, but
potential for more widespread severe weather is there. Per above
southerly winds look to become sustained in the 25 to 35 mph range
with higher gusts.

Saturday/Saturday night...Just as much if not more uncertainty,
especially because of the mesoscale affects of the previous days
convection. Otherwise mid and upper level forcing looks strong.

Above mentioned left front quadrant/jet axis moves very little
during this period. Therefore it will continue to affect most if not
all of the area into the evening hours. During this time it actually
strengthens. The lift looks to finally push east of the area during
the later half of the night.

Also trough axis from northern stream system moves through and
shifts the flow aloft to a west then northwest direction. The the
high pops alone for Saturday night that the forecast blend put in.
Looks reasonable at this time. Much cooler for Saturday as well.

.LONG TERM...(Sunday through Wednesday)
Issued at 201 AM MDT Thu Sep 19 2019

At the start the extended, not much has change compared to 24 hours
ago. The overall pattern has a strong upper-level ridge over the
Eastern Seaboard with a deep upper-level trough over the High
Plains. An associated surface front with this trough over the High
Plains should have already passed through the local area on
Saturday. Behind this front expect mostly dry conditions over the
Central High Plains along with close to normal temperatures as an
upper-level ridge builds over the Front Range and moves towards the

At the same time, the models are showing a cut-off low developing
near the Four Corners region. This setup will help maintain the
upper-level ridge over the area into the end of next week. However,
on Tuesday, the models are showing shortwaves moving out of the
cutoff and up and over the ridge axis. This will aid in the
development of afternoon and evening showers and thunderstorm on
this day. After another brief period of dry conditions on Wednesday,
the cut-off gets kicked out of US Southwest and moves into the High
PLains. The National Blended Model (NBM) shows some showers and
thunderstorms on Thursday; however, there is uncertainty if this
this will pan out with the current trend of the models not
agreeing this far out.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1109 PM MDT Wed Sep 18 2019

For KGLD...looking for mainly VFR conditions for the forecast
period. There are currently scattered low clouds from 09z-13z w/
the potential to become MVFR. VCTS from 20z-23z Thursday.
Winds...E 5-10kts thru 09z...the ESE. By 13z...SSE 5-10kts
increasing to 15-30kts by 20z.

For KMCK...looking for mainly VFR conditions for the forecast
period. There are currently scattered low clouds from 09z-15z w/
the potential to become MVFR. Winds...light/variable thru
15z...then SSE 10-15kts with gusts 20-25kts after 20z.




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