239
FXUS63 KGLD 221053
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
453 AM MDT Sat Jun 22 2024

.KEY MESSAGES...

- Weekend looks to remain hot with highs in the 90s to low 100s.
  Could be a few thunderstorms Sunday afternoon/evening.

- Next week will have 90s for much of the area, with Monday into
  the 100s, and a potential high heat indices.

- Chances for storms each day next week.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 303 AM MDT Sat Jun 22 2024

Across the region this morning, skies are mostly cloudy to cloudy as
a surface low continues a slow trudge northeastward out of the area.
There is a trailing cold front behind this system. Temperatures as
of 100 AM MDT are mainly in the 70s east of the low, with 60s behind
it associated with the front. Similar setup with winds as a
southwesterly flow is occurring ahead of the low/front, with
northwest flow on the backside/with the front. Gusts in both regimes
are up to 20-30 mph at times, mainly away from the low circulation.

Weather concerns for this weekend into next Monday will continue to
focus on the hot, above normal temperatures each day. Also there is
a chance for convection Sunday and Monday afternoon/evening.

Looking aloft, the latest RAP40 500mb analysis and mid level water
vapor imagery are showing a broad expanding ridge over the southern
portions of the country. It will be this feature that will be the
most impactful weather-wise over the CWA during the short term
period. Its current position will bring zonal flow aloft today, but
going into Sunday and Monday, the latest GFS/NAM continue to show
amplification of this ridge into the Rockies, which is going to
result in a shift to W/NW flow aloft each day. Guidance does show a
couple weak shortwaves that pass along the eastern side of this
ridge Sunday and Monday.

At the surface, the region is still seeing extensive cloud cover
from a slow moving surface low as it lifts into south central
Nebraska. A cold front behind this low continues a S/SE push into
the area, bringing a shift to a N/NW flow, replacing the southerly
fetch the area has seen over the past 24 hrs. High pressure will
settle in behind this front during the day, with a slow trek E/SE
into the Plains. Downslope warming aloft, with 850mb temps +24c to
+29c will provide another hot but dry day for the area once the
cloud cover clears the area later today. Northerly winds today will
eventually shift northeasterly tonight and eventually southerly by
Sunday morning as the aforementioned ridge moves east of the area.

Going into Sunday, downslope warming aloft continues through the 24
hour period. With the surface high setting up east and models
bringing a lee-side trough into the Front Range, southerly flow will
usher in a hotter day compared to today area-wide. With
amplification of the upper ridge into the Rockies, there will be a
weak shortwave riding along the eastern side of the ridge. This
system will interact with the surface trough during the afternoon,
triggering a 15-30% chance for convection. The latest NamNest is
showing this convection cropping up around 21z, clearing east by 03z
Monday. With the near surface being so dry and hot(850mb temps +27c
to +32c), storms to be elevated with wind threats should any form
up. PW values around an inch west to 1.50" east could allow for a
locally heavy downpour as well. This activity again clears by mid
evening from west to east.

And for Monday, conditions are a similar setup to Sunday. Southerly
surface flow with downslope warming aloft will give the CWA another
hot day(850mb temps +31c to +35c). A late afternoon/early evening
shortwave passage interacting with a low/front sinking through the
region will trigger some rw/trw potential. This potential
precipitation will be a welcome reprieve to the hot conditions from
the daytime hours. See temperature section below for info concerning
potential Heat Advisory.

For temps, highs for the area this weekend will have a range in the
lower to mid 90s for Saturday, increasing on Sunday from the mid 90s
to the lower 100s. Going into next Monday, the region will be hotter
with a range from the upper 90s into the mid 100s.

With Sunday and Monday expecting to have almost the entire CWA
having at least 100F for daytime highs, there is the possibility for
some locales to come within a few degrees of tying a record. Please
refer to the Climate section below for further information.

Along with the hot, above normal temperatures, humidity will be
present to bring about high heat indices for areas east of Highway
25, especially Monday. Readings could approach 100 to 105. This
could result in the issuance of a Heat Advisory for portions of the
area. Stay tuned.

Lows for tonight will range in the lower to mid 60s. For Sunday
night, mid 60s to lower 70s expected. Going into Monday night, a
range from the mid 60s west into the lower 70s east is expected.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 210 AM MDT Sat Jun 22 2024

Overview: Long range guidance indicates that the Tri-State area
will initially be situated on the northern periphery of an
upper level ridge (centered over the Desert Southwest and
Southern Plains), at the southern fringe of the mid-latitude
westerlies (on Tuesday).. and that the aforementioned ridge will
consolidate/amplify over the Desert Southwest and extend
northward to the 4-Corners and central Rockies (Wed-Thu).. then
flatten and regress southward to the Desert Southwest/Southern
Plains (Thu-Fri) as an upper level low moving ashore the Pacific
NW progresses eastward across the northern Rockies/ Dakotas..
and cyclonic flow aloft envelopes the Intermountain West.

Tue-Wed: Well above average temperatures are apt to persist.
Precipitation chances /convective development/ in this period
will highly depend upon the evolution of the ridge. 00Z 06/22
operational ECMWF guidance indicates that the magnitude,
position and orientation of the ridge will be such that (1)
synoptic subsidence may largely suppress diurnal convective
development along the Colorado Front Range/Palmer Divide and (2)
that low-level forcing/moisture may be insufficient for in-situ
convective development on adjacent portions of the High Plains
(i.e. northwest KS). 00Z 06/22 operational GFS guidance
indicates a similar, albeit less pronounced, ridge.. with the
mid-latitude westerlies in closer proximity to the Tri-State
area on Wednesday.. a somewhat more favorable pattern for late
aft-eve convective development.

Thu-Fri: 00Z ECMWF/GFS operational guidance are in relative
good agreement that upper level flow will back to the SW over
the central Rockies and adjacent High Plains in this period.. as
cyclonic flow aloft envelopes the western CONUS.. and that the
Tri-State area will remain on the far southern fringe of the
mid-latitude westerlies (southwesterlies, in this case). Despite
relatively good agreement on the synoptic pattern, sensible
weather conditions depicted by the GFS are at considerable odds
with those depicted by the ECMWF on Friday, an indication that
mesoscale processes -- e.g. latent heat release and/or airmass
augmentation assoc/w deep convection both upstream and well-
removed from the Tri-State area -- may highly influence the
outcome. With the above in mind, forecast confidence decreases
precipitously by the end of the week. Broadly speaking, expect
above average temperatures and a relative greater potential for
convection.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 451 AM MDT Sat Jun 22 2024

For KGLD, mainly VFR conditions through the forecast period.
Possible for MVFR ceilings from 12z-14z this morning. Winds,
northwest around 10kts, shifting north by 14z 10-20kts. By 00z
Sunday east around 10kts then veering south by 05z.

For KMCK, IFR/MVFR mixed ceilings from 12z-15z before going VFR
through the remainder of the forecast. Winds, northwest
10-20kts through 22z then shifting north. From 00z Sunday
onward, light/variable.

&&

.CLIMATE...
Issued at 302 AM MDT Sat Jun 22 2024

With hot conditions expected over the area Sunday and especially
into Monday, with highs at least 100F area-wide, there could be some
locales coming within a few degrees of at least tying the daily
record(s). The records for Sunday, June 23rd and Monday, June 24th
listed below are for comparison to the expected forecast each day.
Despite the region seeing triple digit heat, most locales are still
below records.



                      Sunday, 6/23           Monday, 6/24


Goodland KS           106F in 2012+          109F in 2012

Burlington CO         106F in 1954           107F in 1954

Hill City KS          111F in 2012           114F in 2012

McCook NE             106F in 2012+          107F in 1943

Colby KS              105F in 1943           107F in 2012

Tribune KS            105F in 1954           109F in 2012

Yuma CO               107F in 1954           103F in 2002

A (+) denotes a multiple year record

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.

&&

$$

SHORT TERM...JN
LONG TERM...BV
AVIATION...JN
CLIMATE...JN