Winter storms set to disrupt Thanksgiving travel across the U.S.

Winter storms are set to strike the United States during Thanksgiving week, potentially disrupting travel for millions of people.

An upper-level trough will move into the West Coast from the northeast Pacific early this week, bringing with it an anomalous subtropical moisture plume. This plume is expected to affect central and southern California on Monday and Tuesday, November 25 – 26.

The moisture plume will primarily target coastal areas and the Sierra Nevada, driven by a surface-level low. In the southern Sierra, areas below 2 440 m (8 000 feet) could face flash flooding on Monday. Excessive rainfall in mountainous areas may also trigger rock and mudslides, along with general debris flow.

In higher elevations of the southern Sierra, heavy snow is anticipated, with 0.9 – 1.2 m (3 – 4 feet) forecast by Wednesday morning, November 27. Some isolated areas may see even higher amounts. By midweek, the moisture plume is expected to shift into the interior western United States.

In the Intermountain West and Colorado Rockies, snowfall of 2.5 – 5 cm (1 – 2 inches) is forecast, with isolated totals of up to 7.6 cm (3 inches). Snow showers are also likely early in the week in parts of the Great Basin.

Near the I-25 corridor, snow accumulations of 5 cm (2 inches) are expected on Monday morning. These conditions, combined with low visibility, could pose challenges for travelers.

In Denver, highs will range from 7 °C (mid-40s °F) on Monday to 0 °C (low 30s °F) by Wednesday. Thanksgiving Day may bring a slight chance of snow, but clearer skies are forecast for Friday, November 29.

Temperatures throughout the week will remain cold.

Nationally, light rain showers are expected across the Ohio Valley and Upper Midwest. Snow may also occur in northern Minnesota and Wisconsin on Monday.

On Tuesday, localized rain is forecast for the Northeast, with light to moderate rainfall throughout the day. While rain could affect the entire East Coast, this system is not expected to be particularly impactful. Northern New England may see up to 25 mm (1 inch) of rain, while southern New England is likely to receive 12.7 mm (0.5 inch) or less.

Snowfall is predicted to intensify from late Tuesday into Wednesday, with increasing accumulations along mountain passes and lower elevations. Winds of up to 56 km/h (35 mph) are expected, creating hazardous driving conditions due to blowing snow.

The central states and Rockies are expected to have the most active weather on Wednesday, November 25 — the big travel day.

“S​now could impact travel in Colorado and Utah, including Denver. Meanwhile, a developing wave of low pressure could bring rain to the mid-Mississippi Valley and parts of the Ohio Valley. There might be a sliver of snowfall or wintry mix on the northern fringe of that rainfall,” Weather.com meteorologists said. “A​t this time, it appears much of the East Coast and West Coast will stay dry and avoid any major travel hassles.”

Windy conditions are expected across the Upper Midwest. Meanwhile, the primary storm will move through the Rockies, bringing rain and snow showers to that region.

Rain is anticipated in the Southern Plains on Wednesday, alongside accumulating snowfall in Colorado and Wyoming.

By the end of Thanksgiving week, a large storm is expected to develop and impact the Northeast.

The storm will intensify on Thanksgiving Day, November 28, spreading rain across much of the South, Ohio Valley, and Mid-Atlantic states. Light snow could develop late in the day over the northern fringes of the storm system.

The Northeast is expected to be impacted by the storm system on Friday. Although it is too early for a detailed forecast, potential scenarios include rainstorms with snow in higher elevations or a significant coastal storm affecting southern New England.

References:

¹ Short Range Public Discussion – WPC – November 25, 2024

² Thanksgiving Weather Travel Forecast: Here’s A Look At Where Rain, Snow Could Interrupt Plans – Weather.com – November 25, 2024

³ Thanksgiving Week Weather in Colorado: Snowstorm to Disrupt Travel Starting Tuesday – Country Herald – November 24, 2024

⁴ Large storm could impact northeast around Thanksgiving. Here’s what we know. – CBS – November 24, 2024