textproduct: Goodland

KEY MESSAGES

- Cooler temperatures, pervasive cloud cover and periods of rain expected through Wednesday.

- Rain is expected to transition to wet snow Tue night into Wed morning, mainly in eastern CO and adjacent KS border counties where temperatures will hover around, or just above, the freezing mark and several inches of accumulating wet snow is possible.

- Light winds and a clearing trend may lead to sub-freezing temps and frost/freeze conditions over much of the area Wed night into Thu morning. A Freeze Watch remains in effect for this period.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 1227 PM MDT Mon May 4 2026

Today, the 500 mb pattern becomes notably more active. In the afternoon/evening, a Polar low near the Great Lakes will extend a trough to the southwest, linking up with another low moving east over the California coast. To the south, we'll have the remnants of the high decaying into a weak ridge. As this is happening in the upper levels, an 850 mb low will strengthen over the CWA, dragging in a late afternoon cold front. These features will cause widespread vorticity Monday evening and overnight, which is the driving force for our next decent round at precipitation.

Before the precipitation and cold front, temperatures will warm into the upper 70s and low 80s, driving RH values across the area into the mid teens, especially south of a weak dryline. As of 1730Z, this dryline is seen on radar and observations draping across northeastern Wichita county, arcing up to the Kit Carson and Cheyenne (CO) county border. Fire weather threats are still low as winds are forecast to remain under 20 kts ahead of the front. However, occasional gusts up around 25 kts may occur, leading to isolated briefly critical fire weather conditions.

The cold front is currently expected to enter the CWA from the north/northeast around 19-21Z. The cold front, the aforementioned dryline, and another weaker dryline, working with the 500 mb vorticity will kick off convection this afternoon in two main areas. The cold front will start some convection across the northern CWA, which will trend to the east-southeast. The second dryline is very weak, but basically runs just south of I-70 through Kansas before it meets with the first dryline. Between the two dry lines is a moist sector. This is the area we're most worried about strong to severe storms occurring due to better forcing. Recent model guidance now shows locations along I-70 initiating at 19-22Z. Instability and shear across the area looks low-end marginal to support severe weather. Most likely threats from these storms would be 0.5-1 inch hail and 40-55 MPH winds kicking up some blowing dust. Due to the storm mode being more of a cluster, the threat of a wall of dust is low, but any strong outflows could reduce visibility to less than a mile in a plume. Lightning striking ahead of the precipitation could also produce a fire threat. The strongest storms look to occur between 20-02Z, becoming more stratiform after this time.

Tonight, temperatures look to cool into the 30s across most of the area. The stratiform precipitation is expected to persist on and off through the night. Embedded storms are possible, but there is basically no threat of severe weather in the overnight hours. There is a 10% chance some snow could mix in early Tuesday morning in the northwestern CWA, but no impacts or accumulation are expected.

Throughout the day Tuesday, precipitation will persist and temperatures will remain capped in the 40s to low 50s. We could still see some embedded storms, but no severe weather is expected.

Overnight Tuesday, temperatures will cool into the upper 20s to mid 30s, due to CAA and the ongoing precipitation absorbing latent heat. As mentioned, the precipitation will be continuing and we are expecting snow to mix in. Most likely areas to see snow by Wednesday morning will be along and west of KS 27. Light accumulations of snow are possible, but roadways will likely become a slushy mix with patchy ice.

Snowfall totals by Wednesday morning could be a couple of inches in eastern Colorado, but the NBM is on the higher side of QPF forecasts. To highlight this, NBM 10th percentile shows areas west of U.S. receiving 0.5" of QPF and eastern Colorado receiving over an inch. Looking at the REFS, the mean amount for the same time period is 0.3" and 0.65" for the same areas. However, REFS mean snowfall accumulation by 12Z Wednesday is very similar to the NBM/NDFD, implying more of the precipitation will occur Tuesday night as snow. Currently, no advisories have been issued for the winter precipitation, but we may need one in eastern Colorado in the coming forecast cycles.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 119 PM MDT Mon May 4 2026

***Synopsis***

Upper-level troughing is forecast to be moving in overhead Wednesday morning, with a slow-moving surface low pressure in the Colorado Rockies. This low is favored to establish a zone of convergence across Kansas Wednesday. As troughing moves off to the east Thursday, a split flow pattern across the Western United States looks to create northwesterly flow over the forecast region. Ensemble guidance suggests the northwesterly flow aloft could last through the end of the period. Several shortwave systems may impact the forecast region during this timeframe.

***Wednesday***

With upper-level troughing overhead on Wednesday, conditions are expected to be climatically cooler, with highs as low as the mid-30s across portions of Eastern Colorado. A Freeze Watch has been issued for Wednesday night across the forecast region except for Graham and Norton Counties in Kansas. Forecast and NBM guidance suggests lows to be in the lower-20s to lower-30s. In addition, the convergence zone across Kansas may be providing precipitation throughout the day. LREF guidance is in favor of little to no CAPE (instability) being present during this time period. Rather, this activity is favored to be driven synoptically by low-level convergence, mid- level warming, and incoming cyclonic motion aloft. NBM 24 hr guidance suggests a fair chance for greater than 0.1 inches of precipitation across the CWA Wednesday. Snowfall is also possible Wednesday with the lower temperatures, potentially lasting through the evening hours. Portions of Eastern Colorado have a 50% chance or higher of 1 inch of snow or greater. Additionally, any snow that falls across the region is anticipated to be wet and heavy snow.

***Thursday-Monday***

As the northwesterly flow establishes itself aloft Thursday, warmer conditions appear favored to return. Current guidance suggests that high temperatures will remain around the 70s through the end of the period, though the shortwave systems embedded in the flow aloft may allow high temperatures to meander lower into the 60s, or higher into the 80s depending on the timing of the shortwaves. Showers and thunderstorms are possible Thursday through Sunday as these systems traverse the area, with LREF guidance suggesting a few hundred J/kg of CAPE to be present each day. NBM 72 hr precipitation guidance suggests that activity between Thursday and Saturday has a chance of providing a total greater than 0.1 inches. Even so, much of the precipitation that falls during this period is forecast to be light rain, with perhaps some weak, localized showers.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1100 PM MDT Mon May 4 2026

..Poor Aviation Weather Tuesday and Tuesday night..

GLD: VFR conditions will deteriorate to MVFR around or shortly before sunrise (~10-11Z Tue) with further deterioration to IFR a few hours after sunrise (~13-15Z). IFR or borderline IFR-LIFR ceilings are expected during the afternoon, along with periods of light rain. Ceilings will further deteriorate to LIFR-VLIFR during the late afternoon and early evening as moderate precipitation develops and overspreads the region. Precip, initially rain, may mix with and/or transition to wet snow Tue evening, near the end of the 06Z TAF period.

MCK: VFR conditions will deteriorate to MVFR around or shortly before sunrise (~10-11Z Tue). MVFR or borderline MVFR-IFR ceilings are expected during the afternoon, along with periods of light rain. Ceilings will further deteriorate to LIFR during the late afternoon and evening, as moderate precipitation develops and overspreads the region. At the McCook terminal, rain is likely to be the primary (if not sole) precip type.

GLD WATCHES/WARNINGS/ADVISORIES

KS...Freeze Watch from Wednesday evening through Thursday morning for KSZ001>003-013>015-027>029-041-042. CO...Freeze Watch from Wednesday evening through Thursday morning for COZ090>092. NE...Freeze Watch from Wednesday evening through Thursday morning for NEZ079>081.