Share

Significant Severe Weather Threat, Including Tornadoes, This Weekend and Early Next Week

April 25, 2014

It's been a relatively quiet start to the severe weather season this year.

To date, not one tornado of EF3 intensity or stronger has been observed anywhere in the U.S. In addition, no tornado-related deaths have been recorded thus far in the U.S. in 2014 through April 24.

(MORE: 2014 Remains Fatality-Free for Tornadoes | Record-Long Wait for Year 's First EF3)

However, the weather pattern is now changing and it appears the threat of severe weather will ramp up through the next five days or so.

If you live from the Plains eastward into parts of the Mississippi Valley, Ohio Valley and South, take note: A potentially significant severe weather threat, including tornadoes, is forecast to develop this weekend and continue into early next week. 

Severe Weather Setup

Background

Disturbance Moves In

Disturbance Moves In

Disturbance Moves In

Disturbance Moves In
Background

Unstable Air Coupled with Wind Shear

Unstable Air Coupled with Wind Shear

Unstable Air Coupled with Wind Shear

Unstable Air Coupled with Wind Shear

Heading into the weekend, a strong, upper-level disturbance will travel east from the Rocky Mountains into the nation's midsection. As it does so, it will pull warm, moist air ahead of it into the central and southern Plains. Warm, moist air is buoyant, and it will easily rise, especially with a few hours of sunshine. This rising air is called atmospheric instability, and it will provide the "fuel" necessary to sustain severe thunderstorms.

By late Saturday and Sunday, a surface low will develop within the central Plains. Ahead of this low, moist air will continue to stream into the Great Plains from the south. At the same time, faster mid-level winds will blow into the Plains from the west, resulting in wind shear (a change in wind speed and direction with height). Wind shear allows thunderstorms to tilt as they build higher in the sky, and the result is long-lived, particularly strong thunderstorms called supercells.

With enough wind shear and instability, supercell thunderstorms can produce and sustain tornadoes in addition to large hail and damaging wind gusts.

This storm system will continue to progress slowly eastward into early next week with multiple rounds of severe storms likely.

For details on the severe threat areas each day, click here.

MORE: Where to NOT Take Shelter During a Tornado

 


Featured Blogs

Cristobal Headed Towards Iceland; 98L Moving Inland Over Texas

By Dr. Jeff Masters
August 28, 2014

Hurricane Cristobal continues to churn northeastwards over the Atlantic towards Iceland. Satellite loops show that Cristobal has its most impressive appearance of its lifetime, with a large symmetric area of heavy thunderstorms. Cristobal will merge with a frontal zone on Friday and transition to a powerful extratropical storm that will likely bring tropical storm-force winds and heavy rain to Iceland on Sunday night.

Record Warmth in Northeastern Canada, Record Cold in Northern Ireland

By Christopher C. Burt
August 26, 2014

August has continued the July pattern of anomalously warm weather in Canada’s far eastern regions with a new all-time record high of 22.7°C (72.9°F) measured at Resolution Island, Nunavut on August 23rd. In contrast, Northern Ireland observed its coldest August temperature on record the morning of August 24th with a -1.9°C (28.6°F) reading.

Live Blog: Tracking Hurricane Arthur as it Approaches North Carolina Coast

By Shaun Tanner
July 3, 2014

This is a live blog set up to provide the latest coverage on Hurricane Arthur as it threatens the North Carolina Coast. Check back often to see what the latest is with Arthur. The most recent updates are at the top.

Tropical Terminology

By Stu Ostro
June 30, 2014

Here is some basic, fundamental terminology related to tropical cyclones. Rather than a comprehensive and/or technical glossary, this represents the essence of the meaning & importance of some key, frequently used terms.

2013-14 - An Interesting Winter From A to Z

By Tom Niziol
May 15, 2014

It was a very interesting winter across a good part of the nation from the Rockies through the Plains to the Northeast. Let's break down the most significant winter storms on a month by month basis.

What the 5th IPCC Assessment Doesn't Include

By Angela Fritz
September 27, 2013

Melting permafrost has the potential to release an additional 1.5 trillion tons of carbon into the atmosphere, and could increase our global average temperature by 1.5°F in addition to our day-to-day human emissions. However, this effect is not included in the IPCC report issued Friday morning, which means the estimates of how Earth's climate will change are likely on the conservative side.