Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 270804
Area Forecast Discussion
National Weather Service Goodland KS
204 AM MDT Thu Apr 27 2017
.SHORT TERM...(This evening through Thursday)
Issued at 307 PM MDT Wed Apr 26 2017
Main forecast issues will be ongoing Frost Advisory and when to
start precipitation during this period. For tonight...all model
output is showing an increase in mid and high level cloud cover
through the night, especially in the northern portions of the
advisory area. Winds and temperatures still look to be the lightest
and coldest in the advisory area. So saw no compelling reason to
change the Frost Advisory. Also due to the deep dry layer in place
and high resolution output much drier than yesterday, removed
precipitation mention from tonight.
For Thursday...There is a rather deep dry layer during the morning
hours. The column moistens up in the afternoon. Models differ on the
exact location of where the mid level circulation ends up tomorrow
afternoon and its evolution. The models would indicate that the lift
will be disorganized.
For the afternoon, depending on which model you choose, there is a
surface low near the southern end of our area with either a cold
front/weak surface over our west with a warm front nosing into our
southeast/east central portion of the area. Models have theta-e
lapse rates becoming negative late in the morning into the afternoon.
Models show little to no qpf in the morning and can understand that
with what the forecast soundings show with the dry layer. However,
ended up starting pops a little sooner due to my neighbors starting
things earlier, which is possible. So increased pops from later in
the morning into the afternoon with highest pops later in the day.
Of concern is the very good lapse rates and cold pool aloft due to
the 700 mb low on top of us. That and instability/index parameters
would indicate that the storms that do develop could become strong.
Update to the Day 2 outlook shows a marginal risk near the area. Due
to the above reasoning will update the HWO to reflect this thinking.
Of minor note, high temperatures have the potential to be cooler
than what I have due to the rather thick cloud cover beginning
earlier in the day and the developing precipitation.
.LONG TERM...(Sunday through Wednesday)
Issued at 203 AM MDT Thu Apr 27 2017
The beginning of the long term period will be impacted by the storm
system that is expected to reach the region Friday and continue
through the weekend. Current guidance shows fair agreement with the
closed low moving northeast over the region, with the backside of
the low moving over the eastern half of the region on Sunday. This
will bring snow to that area, as well as rain once the temperatures
increase throughout the day. By the end of Sunday evening the system
is expected to move out of the region. Snow amounts are still iffy
at this point, so as the weekend approaches there will need to be
fine tuning of the major impacts and the affected locations.
To start next week, the CWA is expected to be dry with northwest
upper level flow over the region. This dry pattern will continue
through Monday afternoon before precipitation chances return with
the movement of a cold front over the area. This will come along
with a broad open wave trough moving over the high Plains.
Precipitation chance will continue through Wednesday afternoon. This
is due to shortwave troughs moving over the region within that large
trough. There could also be isolated and general thunderstorm
chances Tuesday and Wednesday nights. By the end of the week, a
ridge looks to build into the western half of the USA.
Temperatures during the extended period will be in the mid 40s to low
50s on Sunday. The rest of the period will generally be in the 60s
across the area.
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1123 PM MDT Wed Apr 26 2017
Scattered sprinkles/virga moving out of northeast Colorado tonight
will not impact flight categories. Mid and high cloudiness will
gradually increase through the overnight. Scattered showers and
isolated thunderstorms will develop across northeast Colorado and
adjacent parts of northwest Kansas Thursday afternoon, potentially
impacting KGLD. Instability will decrease towards KMCK, so
expecting mainly showers/light rain there by mid to late Thursday
afternoon. Ceilings will lower at both terminals Thursday night
with IFR conditions possible.
KS...Frost Advisory until 9 AM CDT this morning for KSZ003-004-016.
NE...Frost Advisory until 9 AM CDT this morning for NEZ080-081.