textproduct: Goodland

KEY MESSAGES

- A Heat Advisory is in effect again today for counties along and south of a Wallace to Graham county line. Heat index values and air temperatures could reach 105-110 if the front doesn't move through early.

- Storm chances continue daily the next few days.

- Severe storms are possible, with the best chance for severe weather today. Large hail, damaging wind gusts, and flooding look to be the main threats.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 1245 AM MDT Wed Aug 12 2026

Current observations show the center of the low pressure over the area. However, it is not uniform and fairly broad, leading to winds that are somewhat varied in direction and speed. Generally, winds should remain below 10 kts unless a storm outflow moves through. With plenty of moisture lingering in the area and pronounced outflows, showers and storms have been popping up across most of the area. While often short-lived, the reinforced outflows keep moving through and producing storms. While there is a chance this continues through the night, available instability should decrease with these storms popping up. Likely by sunrise, may a few showers and some clouds should be all that is left. With the precipitation and moisture in the area, temperatures will likely stay in the 70s and 80s through most of the night. Western parts of the area should cool to near 60 as skies probably clear.

Today, the surface low is forecast to stagnate over the area. This is a slight change from prior forecasts and have increased the temperature forecast across the area. With this, a Heat Advisory has been issued again for counties along a line from Wallace to Graham and south with temperatures forecast to reach 103-108. Heat index values will likely also reach 105-110, similar to the past few days. The northern row of counties could potentially be cooler and not reach the advisory criteria if the low does push further south and bring in more cooler air, though this looks to be about a 20-30% chance. Winds are forecast to be from the south around 10-15 mph, switching to out of the east/north once the low pushes through a given area.

This afternoon and evening, additional showers and storms are forecast to develop. If a good convergence line develops within the low, the area could see storms develop as early as 2-4pm MT. Otherwise, the main batch looks to develop along the higher terrain to the west of the area during the afternoon with east/southeasterly low level upslope flow. This batch would then try and push into the area during the evening hours. If the low center does deepen near the Tri-State border area, then most of the storm activity will probably move north of Highway 36. Otherwise, most of the area will have chances for storms, with the best chances for Eastern Colorado. Any early storms will have the potential to produce large hail with MUCAPE around 1500-2500 J/kg and mid-level lapse rates around 8-8.5 C/km. Shear around 30kts and freezing levels around 15000-17000 ft look to be the biggest inhibitors. The more likely threat is for wind gusts up to 70 mph. As storms form clusters and lines, organized outflows are possible which may produce wind gusts of 50- 70 mph. There may be some isolated instances of blowing dust, but the lower levels will likely be too mixed for anything organized unless it catches the inversion setup at the right time. Another lower end hazard is the potential for flash flooding. Should the MCS develop as forecast and track through the area, areas may see multiple rounds of storms. Combine this with potential development along the convergence ahead, and rainfall totals above 3" aren't out of the question. But a fair amount of things need to come together, so the overall confidence is around 10-15% that we would see flash flooding. The main batch of storms should clear the area around 12am- 2am CT, if it moves through the area.

For the rest of the night, isolated to scattered showers and storms are possible if outflows get pushed into the area. These would likely be sub-severe and short lived if they did form. Otherwise, mostly cloudy skies and moist low levels should keep temperatures again in the 60s and 70s.

Tomorrow, the upper ridge axis should finally shift east of the area and allow for southwesterly flow aloft and some slightly cooler temperatures. With the surface low forecast to shift only slightly more towards Central Kansas, temperatures may still be fairly warm with 100s possible in southeastern portions of the area. Otherwise, 80s and 90s are forecast across most of the area, with the cooler temperatures favoring the Tri-State border area.

Showers and storms will be possible again late in the day with the area on the wrap around side of the low and shortwaves potentially moving through the upper southwest flow. This would again favor development in the western part of the area, with storms moving north and east as a cluster. Storms may form across the area if a strong enough convergence zone can again form across the backside of the surface low. One of the main changes is that these storms are more likely to develop and move through during the evening and early overnight hours. So that is the forecast for now, but there may be changes depending on what outflows and shifting of the low occurs due to the prior days. Severe storms would be possible, with wind again as the main threat and hail/flooding as secondary threats.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 108 PM MDT Tue Aug 11 2026

The long term period starting on Friday morning looks to begin with southwesterly flow over the forecast area at 500-mb, with ridging just to the east and troughing across the Western United States. Several shortwave troughs embedded in the southwesterly flow may impact the forecast area during this time. Ensemble guidance is in good agreement that this pattern is going to last until Sunday morning when ridging builds over the forecast area. However, an upper level trough/low looks to remain across Northern Mexico and the Four-Corners Region for the remainder of the long term period. A surface low in association with this feature would allow southerly flow to continue across the Southern Plains, but meet easterly flow across Kansas, forming a convergence zone.

Overall, the long term period is favored to consist of moist conditions. On Friday and Saturday, shortwave troughs embedded in the upper level southwesterly flow would allow several surface lows to track over the forecast area. Thunderstorms would be favored to form under this pattern. This is supported by NBM 24 hr guidance, which shows over a 40% chance for greater than 0.1 inches of precipitation across nearly the entire forecast region both days, and as high as a 70-90% chance across portions of Eastern Colorado and Dundy County in Southwest Nebraska Friday. Storms are not currently expected to be severe during this period, as LREF guidance suggests less than a 20% chance of seeing sfc-500mb shear greater than 30 kts across most of the forecast area. However, it should be noted that GFS model soundings show an inverted-V profile up to about 3 km, associated with surface dewpoints around 50. This could support microburst potential, where winds could locally reach around 60-70 mph with thunderstorms. However, this is not the favored scenario, as LREF guidance suggests a 60% chance or better that dew points will reach above 60 F across the forecast area. As such, confidence in severe weather occurring Friday or Saturday is less than 5% at this time. High temperatures are currently forecast in the 80s and lower 90s both Friday and Saturday.

As ridging builds in overhead Sunday and troughing develops across the Four-Corners Region, conditions may start to dry out, as forecast relative humidities (RH) drop from the 50s and 60s on Sunday to the 30s and 40s on Tuesday. This would be driven by a low to the southwest of the forecast area injecting hot, dry air into the incoming southerly flow. Conditions look to remain moist enough for thunderstorm activity to continue Sunday through Tuesday, but it is a point to keep in mind that drier conditions may be coming toward the middle of next week. As for thunderstorm activity during this period, it would be driven by southerly flow meeting easterly flow in Kansas, creating convergence in this zone. Again, LREF guidance is in support of thunderstorms remaining non-severe, showing less than a 20% chance for wind shear greater than 30 kts across most of the forecast region all three days. If hotter and drier conditions can indeed develop, microburst potential may become more of a concern. However, at this range, there is not enough confidence to say that microbursts are likely. This will be another development to watch as we go into next week. High temperatures are forecast in the 80s Sunday and Monday, and then the upper 80s and lower 90s on Tuesday.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1103 PM MDT Tue Aug 11 2026

For KGLD... VFR conditions are forecast through the period. There may be a pop up shower or two during the first few hours as storm outflows continue to move through the area. Low level wind shear is also forecast for the first few hours, but should end around 9-11Z as the low level jet shifts. Otherwise, high clouds are forecast for a majority of the period with winds roughly from the east or south at 10 kts. After 18Z, the winds may gust to 20-25 kts. After 00Z, a front should have moved through the area, providing chances for storms and shifting the prevailing winds to out of the north. Should a storm move over the terminal, be alert for large hail and wind gusts around 50kts. Wind directions may also be erratic in the wake of a storm outflow.

For KMCK... VFR conditions are forecast through the period, but there may be some ceilings around 1000ft between 10-14Z. Low level wind shear is also forecast through the remainder of the night. There is a chance that it could end by 10Z depending on how the low level jet shifts. Otherwise, high clouds and light winds roughly from the east and south are forecast through the majority of the day. A front is forecast to push through around 21-01Z, creating some storm chances and shifting winds to out of the north. The wind should shift to out of the north before the storms form, with the best chances after 02Z. Be alert for wind gusts around 50 kts and erratic wind directions should storms push through.

GLD WATCHES/WARNINGS/ADVISORIES

KS...Heat Advisory from noon MDT /1 PM CDT/ today to 8 PM MDT /9 PM CDT/ this evening for KSZ003-004-014>016-027>029-041-042. CO...None. NE...None.