Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 250916
Area Forecast Discussion
National Weather Service Goodland KS
316 AM MDT MON JUL 25 2016
.SHORT TERM...(Today through Wednesday night)
Issued at 311 AM MDT Mon Jul 25 2016
Main forecast issue will be continued thunderstorm chances.
Satellite showing an amplified pattern over the Pacific. This
transitions a flat ridge over the southern half of the country with
progressive flow over the northern half.
At jet level...The Nam was a little better at the start than
everyone else. At mid levels...The Gfs and Canadian were doing a
little better than the Nam. The HRRR and Sref were doing the best on
the surface wind and pressure field. The Gfs and Canadian were doing
the best on the low level thermal field.
More importantly is model performance on yesterdays and tonights
precipitation event. Not only the 00z Nam but all the convective
allowing models, except for the HRRR showed little to no
precipitation/thunderstorm complex going across late yesterday
afternoon and night. Also the large scale output did not catch what
happened from yesterday afternoon through this morning. This really
significantly lowers my confidence at any of their output early on
due to the environment being drastically affected mesoscale affects
and a large area of rainfall.
Today/tonight...Look to have some lingering rainfall in the east
through mid morning. Then the rest of the day looks dry with
subsidence behind exiting complex and rising heights.
Light upslope winds through the day will be balanced by what looks
to be plenty of sunshine. As a result only made minor adjustments to
the high temperatures.
Only a weak shortwave trough is going across during the night. At
this time will have slight chance pops moving across the area but am
not optimistic of this.
Tuesday/Tuesday night...Heights rise through the middle of the day
in advance of the next shortwave trough. Shortwave trough approaches
the western portion of the area late in the day with the surface
focus still to the west of the area. This shortwave moves across the
area during the night but the models have different solutions on
this. At the same time, a right rear quadrant affects the area
during the afternoon and evening.
So will have a slight chance in the west late in the afternoon. Then
will have chance pops moving across the area during the night. Air
mass is warmer as southerly winds increase with plenty of sun. So
raised maxes a little.
Wednesday/Wednesday night...Heights rise behind whatever shortwave
trough/thunderstorms occurred during the previous night. Then a
complex mess happens after this. Models showing a number of
different waves moving through in the northwest flow aloft and they
poorly resolve the details. It looks like one shortwave moves across
in the afternoon, mainly affecting the eastern portion, and then
another shortwave approaches the western portion of the area later
in the afternoon then moves across the entire area during the night.
Will start out with slight chance pops for the afternoon then
increase pops over most of the area during the night but confidence
is below average. At this time this looks to be the warmest day of
the three, but considering the model differences am a little
uncertain about this.
.LONG TERM...(Thursday through Monday)
Issued at 226 AM MDT Mon Jul 25 2016
AT the beginning of the extended period there is an area of high
pressure aloft over the southwestern U.S. along with a deep
trough over the Mississippi valley region. This will produce a
northwesterly upper level flow over the High Plains into the weekend.
Temperatures are expected to remain near to somewhat above normal
through Saturday. Chance of showers and thunderstorms are possibly
during the evening and overnight hours, for the rest of the work
week, due to diurnal convective activity moving off the Rockies and
into the plains. Friday night continues to be the favorite time
period for the highest possibility of thunderstorms and rain
showers across the Tri-State area, as a couple of the strong short
wave troughs move across the region.
Starting Sunday, high pressure aloft amplifies over the high
plains and into the northeastern U.S. This causes the upper air
pattern to become more southwesterly towards the end of the
period. resulting in drier conditions and temperature reaching
above normal as this upper level high pressure influence the area.
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1125 PM MDT Sun Jul 24 2016
VFR conditions forecast for the TAFs. Winds will be somewhat
erratic tonight due to the lingering storm activity. Current winds
at KGLD are breezy behind the exiting rainfall. These winds should
decline over the next few hours as the rain moves further from the
site. Am thinking that once the storm activity moves far enough
east of the sites in the next couple hours the winds should return
to the prevailing easterly direction and remain there through the
rest of the TAF. There is a chance for thunderstorms again during
the afternoon, however these storms should be isolated and
confined to the evening hours.