610
FXUS63 KGLD 190841
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
241 AM MDT Thu Sep 19 2024

.KEY MESSAGES...

- Critical fire weather conditions are possible over portions of
  the area on Friday, mainly along/west of Hwy 25 where breezy
  southwest winds may develop during the mid-late afternoon.

- Showers and thunderstorms will develop over much, or all, of
  the Tri-State area this weekend as a potent upper level low
  tracks eastward across the Rockies and Central Plains. Severe
  thunderstorms and isolated flooding are possible, mainly
  Saturday afternoon through Sunday morning.

- Low temperatures in the upper 30s are forecast for eastern
  Colorado Monday morning.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 200 PM MDT Wed Sep 18 2024

Southwest flow aloft will continue through Friday between a
trough in the Four Corners region and a ridge over south Texas.
It will be dry today and tomorrow with a weak frontal passage
tomorrow morning have little weather impacts other than a wind
shift. On Friday afternoon, increasing southwest winds and low
humidity in northeast Colorado will result in elevated to near
critical fire weather conditions. Friday night, a weak wave
coming around the southern ridge will result in widely scattered
showers and thunderstorms. Severe storms are not currently
expected due to limited instability, though a few instances of
gusty winds cannot be completely ruled out with favorable DCAPE.
High temperatures through Friday will be in the mid 80s to lower
90s and lows in the 50s and 60s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 236 AM MDT Thu Sep 19 2024

The long-term looks to start off active and become more docile
through early next week.

Saturday morning, a well organized low pressure system will be near
the Four Corners Region, rapidly moving northeast into the High
Plains. Throughout Friday night, a moderately strong 850 mb LLJ will
set up and move additional moisture into the region. The additional
moisture will keep temperatures from cooling off too much Saturday
morning, but will limit day time heating. High temperatures are
expected to be in the upper 70s to mid 80s across the region, but if
the clouds break, expect warmer temperatures. The combination of
warm, moist air with the low pressure system (and associated fronts)
will increase shower and storm intensity in the late afternoon and
evening hours Saturday. Models are fairly consistent with widespread
precipitation being expected. Deep layer shear during this event
looks to increase the potential for severe weather (~5%), but
instability is fairly weak. The heaviest precipitation looks to be
focused between 21Z Saturday through 12Z Sunday, with lighter rain
linger through Sunday. There is a hydrology section below which goes
into more detail about the precipitation.

There is also a small (<10%) chance winds ahead of the storms could
gust around 35 kts in eastern Colorado producing blowing dust. If
there is a clearing of the clouds and the winds are able to pick up,
localized blowing dust could occur, otherwise blowing dust is not
expected to be a major hazard.

As the low moves farther into the CWA, winds will become
northwesterly and start cooling off the area. High temperatures on
Sunday look to remain largely in the upper 60s, and potentially
cooler depending on the efficiency of the CAA. The low pressure
system will take until Sunday night to move out of the area, giving
the area increased PoPs through Sunday evening.

Sunday night, as rising pressure clears out the sky, winds in the
southwestern CWA are expected to weaken. The clear skies and weak
winds will allow for very efficient cooling, potentially dropping
temperatures into the mid 30s by Monday morning. If these ideal
cooling conditions can start occurring at sunset, there is about a
15% potential for light, patchy frost to form in the extreme
southwestern CWA. If the clouds linger or winds are stronger than
forecast, frost will not be an issue. Throughout the CWA Sunday
night, Colorado looks to cool below 40 while the rest of the CWA
will be in the low to mid 40s; autumn is starting to show up.

Once the low moves out, northwesterly flow is expected to dominate
the High Plains through the remainder of the period. This will keep
high temperatures in the 70s. Overnight, winds look to hover around
5-10 kts, keeping the lows in the 40s to low 50s for the rest of the
period. As is typical in northwesterly flow on the High Plains,
shortwaves are bound to occur and could bring isolated to scattered
showers and storms into the area. Monday through Thursday, no
organized systems seem likely, just the potential shortwave showers.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 1053 PM MDT Wed Sep 18 2024

Not much change. VFR prevailing at both KGLD and KMCK overnight.
S winds shifting NW closer towards Thursday morning becoming
breezy towards midday with gusts up around 20 kts. Will see
those NW winds diminishing into the evening hours.

&&

.HYDROLOGY...
Issued at 236 AM MDT Thu Sep 19 2024

An efficient 850mb LLJ is expected to start setting up around 21Z
Friday and continue until Sunday morning. This LLJ will provide a
moist conveyor belt from the Gulf of Mexico into the High Plains. As
mentioned above, an organized low pressure system will move into the
region Saturday, creating a moderately strong forcing mechanism to
start precipitation.

Precipitation looks to start in the eastern CWA Friday evening,
intensifying Saturday afternoon, and begin weakening Sunday morning
before moving out of the area by Sunday evening. Between 21Z
Saturday and 12Z Sunday, nearly the entire Tri-State area will see
at least a couple tenths of rain with the potential (~25%) of seeing
2+ inches in that timeframe. If the higher amounts do occur,
especially in the eastern CWA, there will be increased flooding
concerns. Concerns for flash flooding are low (<10%) with the
potential for areal flooding being slightly high at around 20%.

Throughout the entire event, locations along and northeast of a line
from Oakley, KS to Yuma, CO can expect to see 0.75-1.5 inches of
rain, with pockets of 3+ inches being possible. Locations southwest
of that line will receive less precipitation, likely in the 0.3-0.75
inches of rain.

&&

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

&&

$$

SHORT TERM...024
LONG TERM...CA
AVIATION...024/Sipprell
HYDROLOGY...CA