textproduct: Goodland

KEY MESSAGES

- Severe storms are possible across the entire area this afternoon and evening, mainly between 3-10 pm MDT. 2" hail, 70 mph wind gusts, a few tornadoes, blowing dust and localized flash flooding are all possible.

- Additional storms may develop over portions of northwest KS and southwest NE late tonight and early Sunday morning. Large hail and strong winds are possible with overnight storms.

- Isolated severe storms capable of producing large hail and damaging winds are possible, yet again, Sunday afternoon and evening, mainly between 2-9 PM MDT.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 1235 PM MDT Sat Jun 20 2026

Today, a low that's been sitting in the lee of the Rockies will move across the Central Plains. Highs today are forecast to warm into the mid 80s to mid 90s, with warmest locations in the southwestern CWA. Thanks to that low moving east, the pressure gradient will increase, allowing southerly winds to gust into the 25-35 kts range, but occasional gusts up around 40 kts are expected.

In the mid-afternoon is when we expect to see the bulk of that low enter the western CWA. This is when we expect to see convection begin, likely around 21-23Z. Initially, cells look to cluster into a broken line of convection on the west side of the Colorado border, extending across the entire length of the CWA. Within 2-4 hours, it looks to morph into a linear cluster or messy QLCS with additional cells potentially forming ahead of the storm and being ingested in northwestern Kansas. This increases the risk for merging cells/tornadoes as it approaches and passes KS 25. This wave of storms will be the main threat for this event with the peak severe threat looks to be between 23-4Z. All hazards will be possible, including hail, wind, blowing dust, flash flooding, and a tornado or two. Most significant, realistic hazards look to include hail up to or exceeding 3.5 inches, winds nearing 80-90 MPH, multiple tornadoes, and a wall of dust created from outflow. This wave looks to exit the CWA around 4-6Z.

There is a second wave of convection that guidance is really picking up on now. This second wave looks to form near the Nebraska pan, handle and move to the southeast. Most likely time this wave to impact the CWA will be between 4-8Z. 60-70 MPH winds and hail up to 2 inches look to be the main threat from the second wave, as well as flash flooding. The tornadic threat is low but not 0 for these storms. The severe threat looks to be ending by 9Z, but lingering showers and storms may persist until closer to sunrise. For more information about the flooding threat, please see the hydro section below.

Tonight, as convection and the low finally exit the CWA, winds will weaken and become northerly. Lingering cloud cover will work to keep lows in the mid 50s and mid 60s. There is a chance for patchy fog Sunday morning across most of the CWA.

Sunday, another 500 mb low will create another 850 mb and surface low that will sweep across the southern portions of the Northern Plains. This will extend a cold front through the CWA, sparking off more storms in the afternoon hours. Before that, highs are expected to be nearly identical to Saturday's, maybe a few degrees cooler. Convection looks to start in two locations. The northern section looks to form just north of Yuma and Dundy counties, and move southeast. The southern storms look to form around Flager and Wild Horse and move east. 21-23Z looks to be the start time, and these storms, if they do move in their respective directions, would cluster together around the Colby/Hoxie area. Hail up around in the 1-2 inch range and winds up around 60-70 MPH are the primary threats. Convection looks to weaken around 9Z again. Lows Sunday night do look to be a bit cooler Sunday night behind the cold front, likely dropping into the 50s.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 135 PM MDT Sat Jun 20 2026

***Monday-Wednesday***

Thunderstorms are in the forecast Monday through Wednesday. A 500-mb trough traversing the Northern United States and Southern Canada along with a shortwave ridge over the forecast region looks to produce a surface low pressure across portions of Colorado Monday. A convergence zone would be favored to develop somewhere near Colorado's eastern border, though its exact location and timing of formation is in question. Most LREF solutions suggest that this convergence zone will be associated with around 1200 J/kg of surface- based CAPE (a measure of atmospheric instability) or less, though higher-end scenarios could see up to around 2000 J/kg. At the same time a 500-mb jet streak at the base of the trough looks to be strengthening during the afternoon and evening hours. GFS and EC model soundings indicate that this development could support 0-6 km vertical wind shear of 35-60 kts along the convergence boundary. Storms may be allowed to become severe under this scenario. While all hazards may be possible with this setup, this may need to be refined as we get closer to the event, as thunderstorms in the short term may modify the environment significantly before then.

The risk for thunderstorms continue Tuesday. 850-mb GEFS guidance still shows a low across portions of Colorado, at the same time that the 500-mb trough from Monday moves overhead. This would produce another zone of convergence across the CWA where northerly and southerly surface winds meet. In addition, the 500-mb jet streak looks to remain in place. This pattern may linger into Wednesday afternoon and evening as well. Surface-based CAPE values may be allowed to get a little higher on Tuesday and Wednesday than Monday, as portions of Eastern Colorado and Northwest Kansas have greater than a 50% chance to see over 1000 J/kg based on LREF guidance. Severe thunderstorms would continue to be possible as vertical shear provided by the upper-level jet remains in place. For each day Monday through Wednesday, confidence is around 10-15% in severe thunderstorms occurring.

***Thursday-Saturday***

GEFS and EC 500-mb height mean-spread guidance is consistent with ridging moving in overhead Thursday and Friday. This could promote warmer temperatures going into the weekend. Highs are currently in the mid 70s to lower 80s Thursday, lower to upper 80s on Friday, and lower to mid 90s on Saturday. Thunderstorm potential may still continue Thursday and Friday, though is a lot more uncertain than Monday through Wednesday. If and when thunderstorms occur is contingent on the presence and timing of upper-level shortwave troughs embedded in the ridge. GFS and EC deterministic guidance does show that these features may be present. Confidence is increasing in the presence of these shortwaves on Thursday, as NBM 24-hr precipitation guidance shows that most of the area has a 50- 70% chance of seeing greater than 0.1 inches of precipitation. This confidence decreases Friday, as the same guidance shows at best a 1 in 3 chance for greater than 0.1 inches of precipitation across nearly the entire area. The thunderstorm risk appears to diminish almost entirely by Saturday as ridging takes full affect. Forecast guidance does indicate relative humidities dropping into the teens in portions of Eastern Colorado Saturday afternoon. As such, the potential development of critical fire weather conditions on Saturday is something to keep an eye on as we approach next weekend.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1120 AM MDT Sat Jun 20 2026

KGLD will se VFR conditions prevail until around 22-23Z, when storms move in from the west. Winds are expected to be from south gusting around 30-35 kts this afternoon. These are forecast to be severe storms that last until around 1-4Z. We are expecting IFR ceilings to return around 10Z and lift around 15Z.

KMCK will see the MVFR ceilings break apart lift by 19Z as southerly winds also gust in the 30-35 kts range. Storms look to impact KMCK around 23-01Z, weakening around 3-5Z, but lingering through most of the night. IFR and near minimum ceilings are forecast for tomorrow morning, starting to lift near the tail end of the TAF period.

HYDROLOGY

Issued at 1235 PM MDT Sat Jun 20 2026

Over the next week, we are looking at near daily chances of convection as PWATs range around 0.9-1.75 inch. We are also expecting 0C level to be around 15,000 feet AGL, leading to deep melting layers, promoting efficient rainfall producing storms.

Today is the most aggressive day coming up, two waves of storms are possible. The first wave is expected to quickly move through the CWA, but as it moves east of U.S. 83, back-building convection may lead to training storms. This would likely occur around 3-6Z, ahead of the second wave. The second wave has a 40% chance of being oriented along it's direction of travel, making it a training storm system. Timing for this threat would be around 5-9Z. Each of these two threats could produce a swath of 1.5-3 inches of rain, but if they overlap, 3-5 inches of rain may accumulate. Most likely area to see these high precipitation amounts will be east of a line from Trenton, NE to Oakley, KS.

A Flood Watch has not been issued due to a lack of confidence for location of the highest rainfall amounts. One may be issued later if a specific location seems to be at more of a risk.

Sunday, additional high precipitation storms are forecast to move through the area. By themselves, they pose little flooding threat, but if they move over an already saturated area, the flooding risk returns.

Through Friday, there are returning chances of precipitation across the CWA. Similar to Sunday, if storms keep passing over the same, saturated area, flooding becomes a reoccurring risk.

GLD WATCHES/WARNINGS/ADVISORIES

KS...None. CO...None. NE...None.