Arthur, NE Weather

Key Messages

- Patchy fog is expected Wednesday and Thursday mornings, especially across southwest Nebraska. Any fog that develops should dissipate by late morning.

- Above-normal temperatures are expected through Thursday, with highs in the 70s to lower 80s. Gusty southerly winds develop Thursday afternoon, with unusually mild temperatures expected Thursday night.

- Showers and thunderstorms return for this weekend and persist into early next week, leading to the potential for widespread rainfall accumulations.

Short Term

Issued at 330 AM CDT Wed Oct 21 2026

This morning, increasing low-level moisture across southwestern portions of the area, combined with weak southeasterly flow and associated moisture advection, will support the development of patchy fog. The greatest potential for fog development once again appears to favor southwestern portions of the area, generally along a Curtis-North Platte line and points west. Looking at model and BUFKIT soundings, a nearly saturated layer extending through the lowest 50 to 150 mb, which is deeper than what was observed yesterday morning, along with a low-level inversion and light winds, further supports the potential for fog development. Similar to yesterday, any fog that develops should dissipate by late morning as daytime heating promotes boundary-layer mixing. Into the afternoon and evening hours, the upper-level ridge will continue to amplify across the central United States, supporting clearing skies, relatively light winds, and warmer temperatures. With 850-mb temperatures forecast in the 15 to 20C range, have trended toward the warmer MAV guidance for afternoon highs, with middle to upper 70s expected, particularly across southern and eastern portions of the area. Farther northwest, highs should remain in the upper 60s to lower 70s. Wednesday night lows should remain relatively mild, generally in the middle to upper 40s, as increased low-level moisture remains across the region.

Thursday morning, a similar setup to Wednesday morning may support another round of fog development across portions of southwest and potentially central Nebraska. Increasing southeasterly low-level flow ahead of an approaching western United States trough should promote additional moisture advection into the region, maintaining favorable conditions for low-level saturation. Some uncertainty remains regarding the coverage and extent of fog development, and trends will be monitored over the next several forecast cycles. By Thursday afternoon, the surface pressure gradient will strengthen across the region as lee-side surface low pressure develops ahead of the approaching western trough. This will result in increasing southerly winds, with sustained speeds of 15 to 25 mph and gusts up to 35 mph possible, particularly across portions of the Sandhills. Meanwhile, upper-level ridging across the central United States will remain amplified, supporting continued warm air advection within the lower to middle levels. With 850-mb temperatures remaining in the 15 to 20C range, increasing southerly flow and sufficient boundary- layer mixing should allow temperatures to warm into the middle 70s to lower 80s, with the warmest readings expected across southwest Nebraska. Despite continued moisture advection, the stronger upper- level forcing associated with the approaching trough will remain displaced west of the region, while upper-level ridging maintains generally unfavorable conditions for widespread ascent. As a result, dry conditions are expected through Thursday night.

Thursday night, strengthening southerly flow and a developing low- level jet will maintain warm air advection and limit nocturnal cooling across the region. The combination of persistent low-level mixing and increased moisture should allow overnight temperatures to remain unusually mild, with lows generally in the middle 50s across much of the area. These temperatures would be more than 20 degrees above average for late October, highlighting the anomalously warm air mass in place ahead of the approaching western trough.

Long Term

Issued at 330 AM CDT Wed Oct 21 2026

For Friday, deep upper low pressure will begin to move east towards the Four Corners, with broad southwesterly flow developing aloft across the Plains by Friday morning. At the surface, increasing lee cyclogenesis across eastern Colorado and Wyoming will lead to strengthening south winds across the area by Friday afternoon. This is in response to diurnal mixing tapping into higher momentum flow aloft, and promote wind gusts as high as 35 to 45 miles per hour. Luckily this will also coincide with increasing moisture advection, and this is expected to offset any greater fire weather concerns. The aforementioned surface low pressure will begin to eject east across the area Friday night, with an associated cold front pushing through the area from northwest to southeast by early Saturday afternoon. This front won't drift too far away from the area however, and should stall from northwest Kansas into portions of eastern Nebraska by Saturday night. Some threat for precipitation may arrive with this initial cold frontal passage, though NBM probabilities of >0.10" only increasing to as high as 10-20% across the western Sandhills through early Saturday morning.

The greater threat for precipitation looks to arrive Saturday night and persist through the weekend and potentially into early next week. By Saturday afternoon, the aforementioned surface front will be positioned from far southwest Nebraska to northeastern Nebraska, and will begin to slowly lift back northwards into the area Sunday morning. The broad moisture advection will push PWAT values above 1" by Friday, and these will linger into Sunday night before a second cold front begins to push through by Monday morning. PWAT values this high will approach the 99th percentile climo for late October, with the most anomalous moisture along and ahead of the surface frontal boundary. This is also where at least non-zero MUCAPE is expected to overspread the area Sunday afternoon. Showers and embedded thunderstorms should increase in coverage by Sunday morning and persist through much of the day. Deterministic guidance remain in good agreement with respect to a swath of beneficial rain amounts (~0.5-1.5") though still differ greatly on where exactly this occurs. This, combined with uncertainty on frontal boundary placement, lends uncertainty to the exact location of heaviest rainfall accumulation across the area. As of now, NBM probabilities remain highest (~50-70% of >0.50") from roughly Imperial to O'Neill and points to the east. Should any further eastward trend occur in the placement of deeper moisture (due to a more progressive surface front), the greater accumulations could also trend off to the east of the area. This will continue to be monitored closely.

Surface low pressure then begins to eject east across northern Kansas late Sunday night, reaching eastern Nebraska Monday morning. This drags a stronger cold front through the area by sunrise Monday, quickly ending any lingering precipitation from northwest to southeast. Guidance has begun to come into better agreement with this quick cessation of lingering precipitation, leading to increasing confidence in no mixed or wintry precipitation Monday morning. This brings a return of much cooler highs as well, with temperatures struggling to leave the upper 40s to low 50s Monday afternoon. Zonal flow briefly returns aloft Tuesday, before a northern stream trough begins to cross the northern Plains into Wednesday. This will lead to slightly moderating temperatures and briefly drier conditions, with highs moderating back to the lower 60s for Wednesday.

Aviation

Issued at 1239 PM CDT Wed Oct 21 2026

VFR conditions are expected through this evening. Fog is expected to develop across portions of the southern Sandhills into southwest Nebraska early Thursday morning through mid Thursday morning. Winds will be out of the southeast this afternoon/evening around 5 to 10 kts and become light overnight into tomorrow morning around 5 kts or less.