Saturday, March 9, 2019

Worry Grows Over Possible New Tornado Outbreak Today

According to NOAA's Storm Prediction Center, this area
is at risk of tornadoes today. The yellow area is most
at risk for the twisters, and some of them might be strong.
The percentages are the chance of a tornado hitting
within a 25 mile radius of any given point in that area.
The start of the nation's tornado season has already been too tragic, with the 23 deaths from twisters i Alabama last Sunday.

Today is another potentially dangerous day, with a risk of tornadoes, again some possibly strong in the lower Mississippi Valley.

Before dawn, severe thunderstorms had already fired up from southwestern Missouri to northern Texas. Some storms with large hail were bombarding the Dallas-Fort Worth area early this morning.

As these storms move east, they'll only grow. Or, new rotating supercell thunderstorms will form, and those are the ones that could turn dangerous by this afternoon.

Based on data from NOAA's Storm Prediction Center,  the area under the greatest risk for tornadoes, again some potentially strong, goes from extreme southern Illinois and extreme southeastern Missouri, down through the western parts of Kentucky and Tennessee and into northern Mississippi.

The risk of strong tornadoes is what's got everybody worried. Most tornadoes are relatively weak in the grand scheme of things. Tornado ratings are under something called the Enhanced Fujita, or EF scale. Most tornadoes are EFO, wth 65 to 85 mph winds, or EF1, with winds of 86 to 110 mph and EF2, with winds of up to 135 mph.

These types of tornadoes can cause a lot of damage, are dangerous and sometimes deadly. But most people who hide in windowless interior rooms like closets, or basements survive these storms.

With stronger tornadoes, even if people are warned they're coming, there's sometimes nowhere to go. In the Alabama tornadoes last week, many of the deaths were in mobile homes or standard wood frame homes. The tornado that caused all the deaths last week in Lee County, Alabama was an EF4, with winds of 166 to 200 mph.

As we saw in Alabama, tornadoes of that strength rip houses to shreds, with nothing but widely scattered debris left behind. How do you survive that?

It's impossible to say as of this morning whether any strong tornadoes actually form, but people in the higher risk zone had better pay very close attention to the weather today.

Tornado watches will likely first be issued. Tornado watches mean conditions are favorable for twisters, but they haven't necessarily formed yet. In the riskiest zones, I'd advise people to leave their mobile homes if a tornado watch is issued and find a more substantial building, just in case a tornado actually forms.

Better safe than sorry.
This is the deadly EF4 tornado last Sunday that killed 23 people
in Alabama. Like many big tornadoes in the South and East,
this one lacked the classic funnel shaped and to an untrained
eye might not have even looked  a tornado, but
just an angry mass of clouds. 

Anyone who gets a tornado warning should seek shelter right away. If a warning is issued, they shouldn't go outside or look through windows to see if the tornado is coming.

Especially in the southern and eastern United States, tornadoes are often embedded in downpours, so you can't see them coming. Plus there's a lot of trees and hills in the east, blocking views of approaching tornadoes.

Like many strong tornadoes, the big deadly tornado in Alabama last Sunday didn't have the classic funnel shape that we associate with such storms. Instead, it looked like just a mass of angry dark clouds as it approached. It wasn't clear to the untrained eye that it was actually an EF4 tornado. The same situation could happen today.

Yes, I'm hyperventilating a little here, as for all we know this outbreak of storms could mercifully turn out to be a dud. But it also might not, so this bears watching.

OTHER BAD WEATHER

As is often the case with tornadoes this time of year, the same storm system that is launching today's possible tornadoes is dumping heavy snow far to the north. This state of affairs certainly isn't as dangerous as a twister, but people should heed alerts and warnings in the snow zone.

A wide area from southeastern Montana to Wisconsin is under a winter storm warning for more than six inches of snow. This area has seen a lot of snow in the past six weeks and doesn't need more. Travel is not recommended in these areas.

Here in the Northeast, the storm's warm front will create a burst of snow and some mixed precipitation in much of New England. A winter weather advisory is up for southwestern New England because of this.

Here in Vermont, expect that burst of snow to come through during the morning, depositing a dusting to two inches of snow in most of the state, with two to four inches in many mountain areas and northeastern Vermont.

Winds will increase, too, gusting to 45 mph or so, especially in the Champlain Valley and the western slopes of the Green Mountains.

Especially west of the Green Mountains, temperatures will rise above freezing Sunday afternoon, leaving us with occasional light rain or showers.  Which means much of whatever falls will melt. The showers might stay as snow or sleet east of the Greens.

More snow showers will continue Sunday night through Monday night. Some rain will be mixed in through the valleys, but some high elevations could pick up a few to several inches of snow out of this.

Forecasters are hinting at the first strong warmup of the spring late next week. Highs in the 50s anyone? That's surely possible with this temporary pattern change.

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