Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 191146
Area Forecast Discussion
National Weather Service Goodland KS
546 AM MDT Wed Apr 19 2017
.SHORT TERM...(Today through Friday night)
Issued at 306 AM MDT Wed Apr 19 2017
Forecast issues will be chances of precipitation through the period.
Satellite showing an amplified and blocky flow over the Pacific into
western North America which then transitions to a progressive flow
over the rest of the country. A rather strong shortwave was moving
At jet level...models were close with the Nam and Canadian doing a
little better than the rest. At mid levels...the Canadian and Nam
were also doing a little here as well. The Nam and Rap were doing
well at the surface. Models started out slightly cool on the low
level thermal field but were not too bad.
Today/tonight...An area of stratus and fog has developed to the
north of the front and surface low. So kept or only adjusted
slightly what the previous shifts left for me. Models still showing
some cape and even some light qpf. However there does not look like
a lot of moisture around and neighbors are not going for anything.
However I still would not be surprised if virga or sprinkles took
place. Temperatures will warm with more sun and warmer 850 mb
temperatures so adjusted high temperatures up a little.
Left front quadrant looks to move just north of the area early
today. Jet axis starts out over the northern portion of the area
early in the night. The right rear quadrant moves over and affects
the southeast half of the area during the last half of the night.
Shortwave trough also moves through during the night with adequate
theta-e lapse rates. So have put a slight chance of showers in the
last half of the night.
Thursday/Thursday night...Right rear quadrant remains over the
northern portion of the area during the morning before moving away.
Shortwave ridging during the day will keep it dry. Northerly winds
and cooler air moving will make for cooler temperatures over today.
The ridge moves east during the night as incoming system approaches
from the west. A shortwave trough, negatively tilted, along with a
mid level warm air advection pattern rotates into the area from late
in the evening into the overnight hours.
Based on the above, the builder pops look good and did not make any
changes. There appears to be elevated cape in the column along with
negative theta-e lapse rates in the southwest half. So added
isolated thunderstorms to the rain showers in that area.
Friday/Friday night...There are still some model differences in the
evolution and position of the incoming upper low. The Nam cuts off
the low further north. The latest Ecmwf and Gfs are in good
agreement in developing/moving the low from southeast Colorado and
southwest Kansas during the morning and then moving it into south
central Kansas in the afternoon. The Canadian does the same thing as
the Ecmwf and Gfs except does it slower.
The last two runs of the Gfs are almost identical. The latest Ecmwf
is very close to the 12z run and is just a little further south. The
Gefs mean and a vast majority of the members support the Gfs and
Ecmwf. Considering the ridging in advance of system and behind along
with the strong jet behind the trough definitely fits in with this
scenario. So the day looks wet.
So as a result, I nudged up pops up a little bit. Also there looks
to still be elevated cape in the column and so inserted embedded
thunderstorms. For the day, I also nudged high temperatures down a
little in the southwest half where cloud cover and precipitation
will keep temperatures a little cooler than what the builder gave
Precipitation should gradually decrease during the night as the
system moves east. Temperatures will get cold enough in the far west
that the rain and snow will mix for a short time.
.LONG TERM...(Saturday through Wednesday)
Issued at 210 AM MDT Wed Apr 19 2017
At the start of the extended period the models are showing northwest
flow aloft while ridging builds over the High Plains region. This
will produce dry conditions for most of the weekend over our CWA.
Another disturbance looks to track across the Dakotas and towards
the Great Lakes on Monday and Tuesday. However; only the tail end of
the front associated with this system looks to pass over our local
area. So at this time I see no impact to the region other than maybe
some strong winds.
The next big system to impact the region looks to make its
appearance on Tuesday night and Wednesday. As this system looks to
have similarity to last Friday`s system. As an upper level trough
over the Pacific Northwest dives southeast towards Colorado then.
This looks to produce another round of much needed precipitation on
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 541 AM MDT Wed Apr 19 2017
For Kgld...vfr conditions are expected through the period. West to
southwest winds near 10 knots will shift to the northwest late in
the morning and increase to 15 knots with gusts up to 25 knots.
Those winds end near sunset.
For Kmck...ifr conditions will begin the period and that will
improve to mvfr around 15z then will become vfr quickly after
that. Winds will shift to the north near 10 knots this morning.
Those winds will shift more to the northwest in the afternoon and
increase to near 15 knots with gusts up to 23 knots. Those winds
decrease around 03z.