textproduct: Goodland

KEY MESSAGES

- Southerly winds of 20-25 mph with gusts up to 40-45 mph is possible for portions of the eastern Colorado Counties this morning into the early afternoon hours.

- Chances of rain become widespread late tonight, increasing to as much as a medium to likely (60-90%) chance by Tuesday afternoon.

- Heavy rain is expected by Tuesday afternoon, especially along/south I-70 and along/east US-83, where 1.5 to 2.0 inches, or more, are expected by Wednesday morning.

- A Flood Watch is in effect for the entire area. While rainfall totals are forecast to generally be around 0.5-2.0", there is the possibility for small parts of the area to see 3.0-5.0" of rain.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 130 PM MDT Mon Sep 28 2026

Current observations show the area under southwest flow aloft with an upper low/trough upstream in the Western US while there is an upper ridge over the Southern Plains. This has kept a steady stream of cloud cover moving in from the west and a few sprinkles/showers briefly moving into Eastern Colorado. This should continue through the day and largely keep temperatures steady in the 60s and 70s. Winds have increased a bit as a surface low has developed and deepened along the Front Range. This has brought winds up in Eastern Colorado and far western portions of NW Kansas and SW Nebraska to around 20 mph with gusts to 30 mph. This should continue through much of the afternoon and evening until the surface low gets pushed more into the area. There is the possibility of a few storms developing in Eastern Colorado after 4pm MT with some occasional sunshine providing low amounts of instability. However, it looks like the cloud cover will be too persistent and keep things capped. Should a storm break through, it may produce hail around half an inch to an inch with MUCAPE around 1500 J/kg and effective shear around 45 kts.

Tonight, the winds should again slowly lower through the night as the low pressure expands into the area. Cloudy skies should remain in place across the area and help keep temperatures in the 60s. The cloud cover and some intermittent showers have lowered a chance for fog a bit compared to prior nights. Still, it wouldn't be unreasonable for some fog late in the night close to sunrise with maybe even some dense patches.

Tuesday, the upper trough is forecast to push towards the Four Corners Region while the remnants of Polo merge with the low pressure associated with the upper trough. This is forecast to keep us under a steady stream of moisture from the southwest with cloud cover through much of the day. This would also keep any fog that developed in place for most of the morning. With the cloud cover forecast to persist through the day, temperatures are unlikely to warm much and stay in the 60s and low 70s. Showers and a few storms will be possible through much of the day with the upstream upper trough and ample available moisture. However, limited instability and broad surface pressure should keep most of the accumulations light with a tenth to half an inch forecast across most of the area.

Tuesday night and into Wednesday gets a little less certain as it becomes less clear if the combination with the hurricane remnants will help speed up the system, or cause it to stall near the area. For now, the forecast is that the remnant low of the hurricane will continue to push north and east, bringing stronger forcing into the area and developing heavier bands of rain. These bands would push through and give the area its best chance for rain and highest accumulations. An additional 1-2" is possible with the higher amounts more likely if a band wraps in place. Where precipitation isn't occurring, there should be some patches of fog with the air remaining fairly saturated. This should also keep temperatures in the 60s Tuesday night. Wednesday would then continue the chances for rain in the area, but an encroaching dry slot and/or the system shifting east may confine the rain to just parts of the area. Even if the dry slot does move in, upper level cloud cover should remain and keep temperatures in the 60s to low 70s. Additional precipitation of 1-2" is possible.

Wednesday night would keep the cloud cover and shower chances going, though a faster system may lead to an early clearing. Even with the cloud cover in place, temperatures may cool into the 50s with northerly winds possibly bringing in cooler air.

In regards to the precipitation, the overall expectation for much of this system is that totals would be around 0.5-2" for most of the area. That may seem contradictory with the multiple mentions of 1-2" possible above, but this stems from different areas likely being impacted at the different times of day. As alluded to, there is also uncertainty on how the system evolves across the area. Should the system speed up, our rainfall totals would favor lower end amounts except where storms train within banding. Given this, have opted to keep the amounts low for now. But have issued a flood watch as it isn't unreasonable that we go the other way and end up with totals around 3-5".

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 /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 439 PM MDT Mon Sep 28 2026

For KGLD & KMCK... VFR conditions are forecast for the first 6 to 12 hours, though showers and storms may approach the terminals. KGLD should have storms near the terminal around the start unless the line that is about 50 miles west falls apart. KMCK is more likely to have showers and a lower chance of precipitation. That changes around 12Z when shower chances increase, ceilings lower through 18Z to near 1000ft, and fog may form. The remainder of the period is forecast to be a combination of these conditions, potentially leading to poor aviation conditions. Keep an eye on the conditions.

GLD WATCHES/WARNINGS/ADVISORIES

KS...Flood Watch from Tuesday evening through Thursday afternoon for KSZ001>004-013>016-027>029-041-042. CO...Flood Watch from Tuesday evening through Thursday afternoon for COZ090>092. NE...Flood Watch from Tuesday evening through Thursday afternoon for NEZ079>081.