Q & A - Wednesday’s 6 First Alert Day

OMAHA, Neb. (WOWT) - The primary reason for Wednesday’s First Alert Day is the very strong wind. A High Wind Warning is in effect from 9 AM to 9 PM Wednesday, with gusts 50 to 75 mph likely. Power outages and wind damage are expected, with high fire danger as well.

What is considered severe wind?

The threshold for a Severe Thunderstorm Warning is a wind gust of at least 58 mph (or quarter-sized hail). Once wind gusts reach 70 mph, the Severe Thunderstorm is “Considerable”. Wind gusts of 80+ mph are “Destructive” and trigger a Wireless Emergency Alert.

Will this storm be like the one in July?

The storms that rolled through the Omaha Metro the night of July 9th into early July 10th brought wind gusts over 90 mph to the area. This powerful wind downed trees, caused power outages and other property damage. The winds on Wednesday aren’t expected to be as high, but still significant.

Will the sirens sound?

If wind gusts reach 70 or 75 mph during a thunderstorm Wednesday, the tornado sirens may sound in the Omaha Metro. Wind gusts between 65 and 85 mph are equivalent to an EF-0 tornado and should be taken as seriously as one.

Are these winds like a hurricane?

On the Saffir-Simpson Scale, a Category 1 hurricane produces sustained winds between 74 and 95 mph. Our wind gusts may reach the lower end of this range, but our sustained winds will not nearly as high. Sustained winds Wednesday will likely be between 20 and 40 mph for much of the day.

Will this be a derecho?

“Derecho” is Spanish for “straight ahead” or “direct”. In Meteorology, a derecho is a widespread, long-lived wind storm that causes straight-line damage. A derecho must produce wind gusts of at least 58 mph for more than 250 miles.

The August 2020 derecho that caused widespread damage across Iowa was extremely significant and catastrophic. Wind gusts reached as high as 140 mph in Cedar Rapids!

It is possible once storms get going Wednesday afternoon, severe gusts (58+ mph) could stretch for over 250 miles. This does NOT mean wind gusts will reach 100+ mph. Not every derecho is the same. Remember, it’s all about the length of damaging winds, not the strength (as long as gusts remain 58+ mph).

Any chances of a haboob since it’s been so dry?

According to the AMS (American Meteorological Society) glossary, a haboob is “an intense sandstorm or duststorm caused by strong winds, with sand and/or dust often lofted to heights as high as 5,000 feet”.

The National Weather Service in Pueblo, Colorado, mentioned the threat for blowing dust and reduced visibility in the southeastern Colorado Plains Wednesday. It is possible we could see some blowing dust in our area, especially any dust lofted up and brought in from Colorado.

Our more pressing local concern Wednesday is the High Fire Danger. With incredibly high wind gusts and relative humidity as low as 15%, any fire that does develop will spread rapidly. A Red Flag Warning is in effect from Noon until 9 PM Wednesday.

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