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| Lots of different colors on the map at the National Weather Service home page. That means there's LOTS of weather hazards brewing. |
A good measure of how strong a storm is reading the lowest barometric pressure in the center of the storm.
Some forecasts call for a barometric pressure in the low 970s in Kansas Wednesday, which would set records for the lowest pressure in that area of the country.
To most people, such numbers are esoteric, and I hear some of you saying, "Who the frig cares?"
But a super strong storm like this has real-world consequences, many of them quite dangerous.
This one has it all: The risk of severe thunderstorms and tornadoes, strong, damaging winds, blizzards, floods and more. The main risk zone for this storm is, naturally in a broad area along the track of the storm.
It's gathering steam over northern Mexico and parts of Arizona and New Mexico this morning, then will get stronger very fast as it moves toward the central Plains. It will reach peak intensity over Kansas Wednesday. From there, it will gradually weaken but remain potent as it heads toward the Great Lakes.
(Here in Vermont, the storm will have some effects, but nothing dire. I'll get into that later in this post.)
Let's break down the risks, which will be making the news over the next couple of days.
SEVERE WEATHER/TORNADOES
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| Severe thunderstorms and possible tornadoes are in the forecast for much of Texas later today. |
That's a somewhat unusual for severe storms this early in the season, and the set up is a bit odd for West Texas.
That's a testament to the power of this storm. Usually, western Texas tornadoes are the product of isolated supercells later in the spring and summer.
This time, the storm will fire up a powerful squall line which will race across western Texas today and central Texas tonight before at least temporarily waning. A few supercells might form ahead of the squall line, and there might be a few rotating cells within the squall line that could touch off tornadoes.
Much more widespread with this squall line will be damaging straight line winds.
On Wednesday, the severe weather threat shifts to more populated areas in the lower Mississippi Valley, especially around Louisiana and Arkansas. There definitely is the risk of more tornadoes in this area, which was just hit by some on Saturday, but luckily, this doesn't look like a mega-big outbreak, at least at the moment.
The threat for severe storms will linger Thursday around Mississippi, Alabama and western Tennessee. There is the risk of a tornado or two there.
BLIZZARD
Any storm this strong has a lot of wind with it. On the cold, northwestern side of the storm, it will obviously snow, so that creates a blizzard.
This particular blizzard will focus its attention in a broad strip from northeastern Colorado through western Kansas and Nebraska and into central and western South Dakota.
Yeah, this area gets blizzards all the time, but this one is a bit special, because of the strength of the expected winds. Remember, this storm is likely to be near record strong. In general, the stronger the storm, the stronger the winds.
Which means gusts could reach 75 mph in the Colorado blizzard zone, ranging down to "just" 60 to 65 mph up into South Dakota. That's enough to cause property damage, and knock over any trucks that dare to drive on highways in the region. By the way, the high winds will not be limited to the blizzard zone
Next:
HIGH WINDS
A remarkably huge area is under high wind watches and warnings because this storm is soon to be so strong and so large. The wind alerts extend from New Mexico to South Dakota. In this huge areas, wind gusts of 60 mph or more will be common tomorrow. In parts of Kansas, winds are expected to gust as high as 80 mph.
The Plains are normally windy, but 80 mph is ridiculous. A few places in western and central Kansas will have wind damage as bad as a weak tornado, but no tornadoes will come close to Kansas in this particular storm. It's just the power of the parent storm whipping huge gusts through this area.
Wind gusts in the 70 to even 80 mph range are forecast for a few spots in New Mexico, northern Texas and western Oklahoma as well.
FLOODING
This big storm has the power to pull a lot of moisture out of the Gulf of Mexico once it emerges into the Plains tonight and tomorrow. A big area from Texas to Minnesota can expect one to three inches of rain out of this.
Flood watches cover a big area from much of Kansas, eastern Nebraska, the eastern Dakotas, much of Minnesota, Iowa and Wisconsin.
In the more northern areas, say from Nebraska and central Iowa north, it's been an incredibly harsh winter. Parts of the Dakotas, Minnesota, Wisconsin and northern Iowa had record amounts of snow in February. Because it was such a cold February, most of that snow is still on the ground. Plus, the ground there is frozen through a deep layer, so runoff can't soak in. It will, well, run off.
The high water will affect streams and rivers, of course. The added problem is storm drains are clogged by ice in snow in towns and cities throughout this region. With all the rain and snow melt, there will be lots and lots of street, parking lot and basement flooding in all these communities, including some big ones like Sioux Falls, Minneapolis, and Sioux City.
VERMONT EFFECTS
Like so many storms this winter and early spring, we here in Vermont are escaping the worst effects of this storm.
It will fling a welcome surge of warm air into the state starting tomorrow, but especially on Thursday and Friday. By then, temperatures will reach the 50s. It will stay well above freezing Thursday night as well.
This will get the snow melting, and ice moving on rivers. So we are at risk of ice jam flooding out of this, so it's worth keeping an eye on.
Luckily, rainfall doesn't look like it will be particularly heavy with this, so it won't be as bad as it could get. Plus, it will get cold again by Sunday, temporarily shutting off the snow melt and letting any high water recede.
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