-- Discussion containing changed information from previous version are highlighted. --
665
FXUS63 KGLD 280240
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
840 PM MDT Mon May 27 2024

.KEY MESSAGES...

- Relatively mild conditions with highs around 80 and winds
  generally below 10-15 mph are forecast for Memorial Day and
  Tuesday. A few non-severe, showers and storms are possible.

- Warm and active pattern is expected through the work week,
  with chances for storms bringing an associated flooding risk.

&&

.UPDATE...
-- Changed Discussion --
Issued at 830 PM MDT Mon May 27 2024

18z/00z NAM and latest HRRR model runs are all showing modest to
significant CAPE in the 1km and 2km layers moving into the
southern and southwest portions of the forecast area from the
south in the 12z-16z timeframe. CIN values at 1 and 2km are very
low. It appears that a 700mb disturbance will move into the area
of instability to support at least a slight chance of
thunderstorms in the counties listed above in the early to mid
morning hours. Should thunderstorms develop, they would be
capable of producing hail up to the size of ping pong balls.

From now through 12z, we should start seeing a slight increase
in shower/thunderstorm activity as weather systems move off the
Palmer Divide and Cheyenne Ridge and through the area. At this
time, severe weather is not expected with this activity.
-- End Changed Discussion --

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 150 PM MDT Mon May 27 2024

Abundant sunshine, light winds, and near normal temperatures
are making for a pleasant afternoon this Memorial Day. Overnight,
temperatures fall into the middle 40s to middle 50s. A weak
wave moving through later this evening into the morning hours
may initiate a few sprinkles/showers or at least an increase in
mid-level cloud cover.

A more active pattern returns following the holiday as we head into
the work week, bringing decent moisture into the region. This uptick
in moisture will allow for an increase in storm chances as waves
continue through the flow; additionally will be monitoring for
flooding potential as multiple days of locally heavy rainfall are
possible.

While the upper ridge moves over the Rockies on Tuesday,
an embedded disturbance will move through from the southwest,
introducing slight chance to chance PoPs by afternoon, continuing
into the evening and overnight period. A few storms may develop by
mid afternoon over eastern Colorado and move generally east-
southeastward across locations along/south of I-70. PWAT values are
forecast to be in the ~1-1.25 inch range. WPC continues a marginal
risk for excessive rainfall across far southern portions of the
area, including Greeley and Wichita counties. Severe weather is
currently not expected. Afternoon highs are forecast in the low to
mid 80s; overnight lows are forecast in the low to mid 50s.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 150 PM MDT Mon May 27 2024

Around mid-week, the upper ridge will move over the Plains, and an
upper trough will enter the western CONUS. This will shove the ridge
eastward and prompt shower/storm development by Wednesday afternoon-
evening. SPC continues a marginal risk for severe weather across
western portions of the area, generally along/west of Hwy 27.
Primary hazards with any severe storms include large hail and
damaging wind gusts. Guidance is picking up on storm development
over the high terrain to our west in the afternoon, tracking
eastward into our area and clustering together by the mid-afternoon
to evening hours. WPC also continues a marginal risk for excessive
rainfall across the entire area on Wednesday.

During the latter part of the work week, the upper low swings across
the western Canada/US border, generating additional waves as it does
so, allowing better chances for showers/storms (greatest chances on
Thursday at around 50-75% when PWAT values approach 1.5 inches
across eastern portions). Severe weather along with a flooding risk
will be possible. Shear values to around 30-35 knots and CAPE values
reaching 2000-3000+ J/kg are forecast for Thursday; lesser
instability (CAPE to around 1000-1500 J/kg) but greater shear (~50-
60 knots) forecast for Friday. WPC has included locations generally
east of Hwy 27 in at least a marginal risk for excessive rainfall on
Thursday; the slight risk clips eastern Graham county. Friday`s PWAT
values come down into the 0.8 to 1.15 inch range - some flooding may
still be possible, concern will focus on locations receiving heavy
rainfall in previous days, resulting in saturated soils.

Heading into the weekend and start of the next week, there is lesser
confidence at this range; however, the current forecast calls for
slight chance showers/storms and a warming trend.

Regarding temperatures, highs are forecast generally in the upper
70s to middle 80s, slightly cooler at the close of the work week.
Highs might then climb into the upper 80s to near 90 by the
start of the next week. Overnight lows are forecast generally in
the 50s.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 455 PM MDT Mon May 27 2024

KGLD...VFR conditions are expected through the period. A
northeast wind under 10kts at taf issuance will veer to the east
at similar speeds by 03z, continuing to the east-southeast after
20z with speeds around 12-13kts and some gusts 20-25kts.
Presently, no precipitation is expected. There are a few windows
of opportunity for showers/thunderstorms to impact the
terminal. The first is around 09z as a weather system moves
through from the west. The second is in the 19z-21z timeframe.
Given the low confidence in any thunderstorm impacting the
terminal, will leave out of the forecast at this time.

KMCK...VFR conditions are expected through the period. A
northerly wind under 10kts at taf issuance will become light and
variable from 02z-16z. After 17z, easterly winds up to 11kts
with a few gusts are forecast. Presently, showers and
thunderstorms are not expected to impact the terminal.

&&

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

&&

$$

UPDATE...99
SHORT TERM...CC
LONG TERM...CC
AVIATION...99