782
FXUS63 KGLD 160737
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
137 AM MDT Mon Sep 16 2024

.KEY MESSAGES...

- Above normal daytime temperatures continue through Friday. |

- Weather pattern becomes more favorable for rainfall,
  especially Tuesday afternoon through Tuesday night (40%-70%
  pops Tuesday night) with 50% chances for rainfall Friday
  night.

- Windy conditions expected Monday through Tuesday.

&&

.UPDATE...
Issued at 1051 PM MDT Sun Sep 15 2024

Intense area of winds, apparently due to weak inversion
interacting with increasing low level jet seems focused around
the Goodland area, where temperatures remain just warm enough to
allow deeper mixing and aided by decaying showers. This jet is
expected to shift east and north and decrease sharply in the
next 2 hours. Gusts up to 69 mph were observed at the KGLD
airport, with the strongest winds per velocity data impinging
on the area right now. Have extended warning for Sherman county
until 06Z, as winds have not materialized in the other parts of
the warning.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 135 PM MDT Sun Sep 15 2024

Tonight...a weather system moves across the area from southeast
Colorado. Sufficient mid level moisture (700-500mb) and some
elevated instability support 20% chances for showers and
thunderstorms across all but Sheridan and Gove counties, mainly up
through midnight. Low temperatures are forecast to be in the middle
50s to middle 60s.

Monday-Monday night...a large deep upper level low pressure area
over central California in the morning is forecast to move into
southeast Idaho/northeast Nevada by 12z Tuesday, similar to
forecasts the past few days. Another weather system moves across the
area from the southwest, supporting 20% chances for showers and
thunderstorms from late morning through the overnight hours. Cant
ignore possible signals from the GFS/NAM models that a few storms
could produce some gusty outflow winds which may produce some
blowing dust. Southerly winds increase through the day with gusts in
the 30 to 40 mph range. Overnight, southerly winds gusting up to 25
mph are anticipated. High temperatures are forecast to be in the
middle 80s to lower 90s with low temperatures in the middle 50s to
middle 60s.

Tuesday-Tuesday night...as the core of the upper level low lifts
northeast into Montana by 12z Wednesday (becoming negatively
tilted), another closed low drops into the base of the trough
over the western part of the country. A strong surface pressure
gradient will result in southerly winds gusting in the 35 to 45
mph range during the day, decreasing slowly overnight while
veering to the southwest and west. Presently, locally developed
blowing dust/dust storm research does not show impactful blowing
dust across the area impacting multiple counties. However,
given that some fields are being worked, its possible there
could be some very localized blowing dust areas.

A more significant weather system moves into the western half of the
area during the afternoon, supporting 20%-30% chances for showers
and thunderstorms. Precipitation chances increase into the 40%-70%
chance range by midnight then decrease from west to east with 20%-
70% chances generally east of Highway 25. The western half of the
area is outlooked with a Marginal Risk for severe thunderstorms.

High temperatures remain above normal in the upper 80s to lower 90s
with low temperatures in the upper 40s to middle 60s.

Wednesday-Wednesday night...the forecast area remains under
southwest flow aloft, in between low pressure systems over Montana
and southwest California and ridging to our east. Drier air moves
into the area from the west, shutting down any chances for rainfall.
High temperatures will be in the lower 80s to near 90 with low
temperatures in the lower 50s to middle 60s.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 136 AM MDT Mon Sep 16 2024

The latest runs of the GFS/ECMWF both show with the passage of the
system for Tuesday night, upper ridge re-amplifies over the Plains
region setting up SW flow aloft for the two day period. At the
surface, there will be a low over eastern Colorado that meanders
eastward on Wednesday w/ a front extending over northern tier zones.
Guidance on Thursday sets up another low over Colorado on Thursday
as well, but this system will not push east until Friday.

So with SW flow aloft for Wed/Thu and a southerly flow during the
daytime hours, the region will see near to above normal warmth each
day. The position of the low each day will dry conditions for
portions of the area each afternoon. RH values Wednesday will range
in the mid teens to lower 20s from Highway 27 and west. On Thursday,
mid and upper teens spread further east towards the Highway 25
corridor. As a result, increased fire wx conditions will ensue.
Winds each day remain below criteria(25 mph).

For Friday on through Sunday, both models will bring the broad
shortwave over the western portion of the country into the Rockies
and lifting E/NE by Sunday night. There is some inconsistency as to
the timing/placement of the upper system which will affect QPF
potential/duration. A 700mb trough/low will traverse the CWA during
this time, interacting with a cold front to trigger rw/trw. High
pressure to the east will stall the eastward advance of this system.
This will allow for decent precip chances Fri(20-30%), Fri night(40-
60%), Sat(30-40%), decreasing to 20-30% Saturday night as the system
begins to lift out of the area. Lingering 15% chances in the far
northeast early Sunday morning before dry wx ensues late Sunday
onward. While the potential for strong storms is possible as the
front moves through the area, will wait to see how the system
progresses to highlight further. System track favors the highest QPF
potential in the E/NE zones where WPC QPF has over an inch possible.

For temps, looking for highs on Wednesday to range in the 80s, with
a mix of 80s and 90s on Thursday. On Friday as a cold front begins
to work into the area, a wide range from the upper 70s to the upper
80s is expected, warmest along/east of Highway 25. For the upcoming
weekend into next Monday, a cool down with 70s expected. Overnight
lows will transition from the 50s and 60s Wednesday and Thursday
nights, to a mix of 40s to lower 50s(east) from Saturday night
onward.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 542 PM MDT Sun Sep 15 2024

Scattered thunderstorms will persist through 02z and may get
into vicinity of GLD terminal, but flight catagories will likely
remain VFR due to very high cloud bases and minimal
precipitation. Gusty variable winds would be most likely impact
if storms approach. Otherwise, with winds diminishing overnight
and low level jet increasing, llws will be an issue at MCK
around 06z. Othwerwise minimal aviation impacts expected until
after 22z when threat for thunderstorms will increase.

&&

.FIRE WEATHER...
Issued at 335 AM MDT Sun Sep 15 2024

Sunday...localized Near Critical fire wx conditions are
expected over western portions of Kit Carson/Cheyenne counties
in Colorado this afternoon. Winds are expected to hit criteria
with gusts up to 20-30 mph. RH values however will reach into
the upper teens to lower 20s. East of this area to the Highway
27 corridor, RH values will drop into the mid and upper 20s.

Monday and Tuesday...gusty southerly winds are expected area-
wide during the afternoon hours. Gusts to 30-40 mph are
possible with some localized higher amounts possible. RH values
each day will range above criteria in the 20s, but with areas
fuels already dry, the expected gusts could allow any fires that
may occur to be problematic. The chances for rain will aid in
any potential late day fires should they occur.

&&

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

&&

$$

UPDATE...JRM
SHORT TERM...99
LONG TERM...JN
AVIATION...JRM
FIRE WEATHER...JN