textproduct: Goodland

KEY MESSAGES

- Scattered showers this morning will gradually increase in coverage and intensity through the day, becoming widespread tonight.

- A Flood Watch is in effect for the entire area starting tonight and continuing through the day on Thursday. While rainfall totals are forecast to generally be around 1-3" during that time, there is the possibility for some parts of the area to see 3-5" of rain.

- There is a marginal risk for severe thunderstorms Wednesday afternoon and early evening. Wind and hail will be the main hazards, but a brief tornado will also be possible.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 1200 PM MDT Tue Sep 29 2026

Upper low over southern California today will move into the Four Corners region tonight, northern New Mexico and eastern Colorado Wednesday and into the Tri State area Wednesday night. Scattered showers this morning will gradually increase in coverage from the south through the afternoon and evening, followed by widespread rain after midnight through Wednesday morning, with embedded areas of moderate to heavy rain during that time. Models show 12-hour QPF (06z to 18z) of 1-2" across much of the area but as much as 2-4" where training occurs. CAMs do differ with how far north to bring the heavier rain totals, with highest confidence south of Interstate 70. There will be some risk of flash flooding during that time, if rain can fall in a short enough period of time. A dry slot will overspread the area from the south by mid to late Wednesday morning which may temporarily result in a break in the rain, primarily south of Interstate 70. However, scattered showers and thunderstorms will quickly redevelop Wednesday afternoon with the upper low directly overhead. REFS shows instability in southern and eastern areas of 500-1000 j/kg and around 40 kts of deep layer shear. If there is any clearing at all with the dry slot instability could be higher. There is currently a marginal risk for severe thunderstorms in those areas for wind and hail, and a brief tornado may also be possible given the favorable set-up of a closed upper low directly over the area enhancing 0-3 km helicity values. Additional storms may be possible even into Colorado, though instability will be limited further west. Any severe threat will likely end early Wednesday evening with the loss of instability, transitioning to scattered to numerous showers and isolated thunderstorms through the rest of the night as the upper low will be slow to move out. The heavy rain and flooding threat will continue, with eastern areas somewhat favored by the latest model runs Wednesday night (east of Highway 83).

Temperatures through the period will be below normal due to clouds and precipitation. Highs will be in the 60s to lower 70s and lows mainly in the 50s.

LONG TERM /THURSDAY THROUGH MONDAY/

Issued at 231 PM MDT Mon Sep 28 2026

Thursday through Friday:

Synoptically, the upper level trough will begin moving into the Tri- State area Thursday morning. The majority of guidance indicates that the center of the trough will track to the southeast of the County Warning Area (CWA). By Friday, the system is expected to move out of the CWA, leaving our upper level flow mainly from the northwest to north.

At the surface, guidance indicates a boundary will move through from the northwest, as well as a potential surface low to the southeast. Expect breezy winds Thursday morning. Gusts of 30-45 mph are currently forecast, with higher gusts expected across the Colorado counties as well as areas south of I-70. Highs on Thursday and Friday are forecast to be in the 60s to lower 70s.

The main hazard associated with this system will be heavy rainfall. Storm total precipitation guidance shows 1-4 inches across the area by Friday night into Saturday morning, with the majority of guidance agreeing the higher amounts staying south of the Nebraska border. However, some models, such as the ICON and GDPS, show a heavy precipitation band of 4-5 inches right along the eastern border of the CWA. The LREF shows a 10-25% probability of exceeding 3 inches by Friday night. Ultimately, these totals will depend heavily on the track of the upper level trough and potential surface low set up. A farther north track would shift the the higher precipitation amounts northward. A flood watch remains in effect for the CWA through Thursday afternoon.

Saturday through Monday:

Synoptically, for the weekend into the early next week, upper level flow returns predominantly for the northwest as the jet stream remains near the US/Can border. Certain long range models, such as the GFS, depict an upper level shortwave detaching from the main jet and moving through the area Saturday afternoon. The ECMWF and Canadian-NH models show a weaker, more subtle shortwave feature. The Probabilities of Precipitation (PoPs) for the weekend remain under 10%. If this feature becomes strong then, it could increase our precipitation chances.

High temperatures though the weekend are forecast to remain below 80 degrees. Saturday and Monday highs will be in the low to mid 70s across the Tri-State area, with a brief "cooldown" into the 60s on Sunday. Winds throughout the latter half of the long term period look fairly breezy, with Saturday having the highest forecast gusts in the 20-30 mph range as yet another boundary passes through.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1103 AM MDT Tue Sep 29 2026

For KGLD & KMCK... VFR conditions are forecast through at least 02Z, with maybe a few passing showers. Winds should generally remain below 10 kts during this period. After 02Z, chances start to increase for ceilings to lower and fog to try and form. Once low ceilings and or fog form, expect them to bring worse flying conditions with ceilings eventually lowering to around 200-500 ft and visibility maybe reaching 1SM. The worse conditions are more likely after 09Z. After 09Z is when the better chances for rain are forecast with precipitation moving in from the south. Most of the precipitation should just be rain showers, but a few storms may mix in at times, especially after 15Z.

GLD WATCHES/WARNINGS/ADVISORIES

KS...Flood Watch from 6 PM MDT /7 PM CDT/ this evening through Thursday afternoon for KSZ001>004-013>016-027>029-041-042. CO...Flood Watch from 6 PM MDT this evening through Thursday afternoon for COZ090>092. NE...Flood Watch from 6 PM MDT /7 PM CDT/ this evening through Thursday afternoon for NEZ079>081.