The West Virginia Shield is in full effect

The moderate risk for severe weather that I noted yesterday was downgraded to a slight risk this morning, though there are still a few reports of significant severe weather, namely enormous hail up to 4 inches in diameter in eastern Kentucky. Wind damage has been widespread through the region as well. Take a look at the severe weather that has been observed to this point.
West Virginia dome
Perception bias leads people to believe that there is some sort of shield that protects them from severe weather (the so-called Arch Effect in St. Louis, for example) but it’s actually a matter of odds. Major cities don’t get hit as often because they don’t take up as much space, so it FEELS like they are safer, though the threat is just as real. Of course (and the day is definitely long from being done) it’s getting harder to believe that West Virginia doesn’t have a dome around it.
(As I say this, there are severe storms east of Lexington, Kentucky with a chance of grazing the state and a line developing from just northwest of Columbus, Ohio to north of Louisville, Kentucky, so the day isn’t over yet, but by golly it looks like West Virginia is going to dodge another bullet.

Baked potatoes

In case you were wondering, yes, every Idaho related story requires a potato pun. This time, the verification for Pocatello just made it too easy. Temperatures climbed all the way to 90 on Saturday, which will leave anyone french fried. The strange thing that I noticed was how warm the overnight lows were forecast to be by several outlets. With clear skies and dry air, the warm air radiated out overnight, and despite the afternoon heat, it was bound to be fairly chilly in the morning. Accuweather and Victoria-Weather saw this coming, but there were those who simply didn’t get the memo. I think this shows that we have an eye for this, and they are simply tater tots.
Actuals: Friday – High 85, Low 48
Saturday – High 90, Low 52

Grade: A

West Virginia in for a rare severe weather out break

An active upper level trough is digging it’s way into the Ohio Valley, and the Storm Prediction Center has issued a moderate risk for portions of the Ohio Valley, particularly West Virginia and much of eastern Ohio, primarily because of the threat for significant severe weather (hurricane strength wind, 2 inch hail or tornadoes EF2 or stronger). Before I continue, here is the outlook as the SPC has foreseen.

WV moderate

As you may have noticed, I said the threat for a severe weather outbreak is rare in West Virginia (though not unheard of). Take a look at the following climatology (via the SPC) for this time of year, showing the frequency of severe tornadoes, wind and hail, and note that West Virginia has a lower risk than everywhere around them.

WV tornadoes

WV winds

WV hail

In particular, look at this, the climatology for significant wind this time of year in West Virginia. West Virginia functions as the hole in a donut!

WV sigwind

Given that it’s so unusual to see terrible thunderstorms in this part of the world, this moderate risk wasn’t issued lightly. Take care tomorrow in the Mountaineer State!

The Week Ahead 7/27/14-8/2/14

July is already almost to a close. Nothing strange coming this week, I don’t think. I guess we’ll find out, though.

map

Monday – Springfield, Missouri
Tuesday – Columbus, Georgia
Wednesday – Pueblo, Colorado; Road Trip from Columbus to Pueblo
Friday – Road Trip from Monroe, Louisiana to Youngstown, Ohio

Weirton, West Virginia

Weirton is just across the Ohio River from Steubenville, a town more people have heard of, I’m sure, but the metro area is listed as “Weirton-Steubenville” so I’m calling it Weirton.

Weirton/Steubenville does not have an aerodrome, but the temperature at nearby Wheeling was 69 degrees, and clear skies are being noted across the region. High pressure has settled into the Great Lakes and Upper Ohio Valley, and looked to remain in place through the rest of the day today.
Upper level flow is stronger than normal for this time of year, and a surface low will organize over Lake Suoerior as a result of an advancing jet streak overnight tonight. A weak assciated trough will dangle south to the Lower Ohio Valley and move east through the day, ultimately touching off some isolated showers and storms in Weirton late tomorrow night. The trough will strengthen into a front, and overnight, light showers and thunderstorms over the Great Lakes and Ohio Valley will become stronger and more widespread. Model guidance is nearly unanimous in suggesting a vorticity maximum developing over Ohio and moving through the West Virginia Panhandle by evening. The extra energy in the atmosphere will make severe weather more likely for Sunday evening, with the threat for showers and storms throughout the morning as well.
Tomorrow – Increasing clouds, with an isolated thunderstorm late, High – 85, Low 58
Sunday – Thunderstorms, some severe late, High 81, Low 67

TWC: Tomorrow – Isolated T-Storms High 86, Low 60
Sunday – Scattered T-Storms. Potential for severe thunderstorms High 83, Low 67

AW: Tomorrow – Clouds and sun with a shower or thunderstorm around; more humid High 83, Low 59
Sunday – A couple of showers and a heavy thunderstorm; mostly cloudy and humid; thunderstorms can be severe High 82, Low 68

NWS: Tomorrow – A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, High 84, Low 59
Sunday – Showers and thunderstorms likely, mainly after 11am. Cloudy, High 82, Low 68

WB: Tomorrow – Partly sunny in the morning…then mostly cloudy with a chance of showers and thunderstorms in the afternoon. High 83, Low 59
Sunday – Showers and thunderstorms likely High 81, Low 68

WN: Tomorrow – Mostly Cloudy with Isolated Showers High 85, Low 59
Sunday – Mostly Cloudy with Scattered Storms High 82, Low 68

Plenty of sunny skies this afternoon for West Virginia. Ejoy it, and stay tuned to the weather on Sunday!
Weirton

Pocatello, Idaho

Today we visit Idaho! The state with the least amount of land border with Canada! Let’s see how the fine folks of Pocatello are doing and if their weekend will be as beautiful as the Rockies…

At 9pm MDT, the temperature in Pocatello, ID is 66 degrees under fair skies. A ridge of high pressure is pushing over the Pacific Northwest and into the Northern Rockies behind a cold front that’s shifting through Montana/Wyoming. The front connects up to an area of low pressure sitting over central Alberta/Saskatchewan. The low remains mostly stationary over the next 24 hrs before it shifts towards the Dakotas and the high pressure builds in a bit further over the Northwest US. What does all this mean for our friends in Pocatello? It means sunny skies and warm temps as an upper ridge continues to build throughout the Western US. Could be some hot potato weather for the weekend! Anybody? Anybody? Yeah i know, it was bad…

Friday: Sunny. High 85, Low 51.
Saturday: Continued sunny, warmer. High 89, Low 52

TWC: Friday: Sunny. High 87, Low 52.
Saturday: Sunny. High 90, Low 55.

AW: Friday: Plenty of sunshine. High 85, Low 48.
Saturday: Plenty of sunshine. High 88, Low 50.

NWS: Friday: Sunny. High 83, Low 57.
Saturday: Sunny. High 87, Low 57.

WB: Friday: Sunny. High 79, Low 55.
Saturday: Sunny. High 83, Low 54.

WN: Friday: Sunny. High 82, Low 57.
Saturday: Sunny. High 88, Low 61.

Here we see the storm system sitting up in central Alberta, with the Northwest US fairly quiet. It’ll stay that way for the next couple of days as temperatures increase.
PocatelloSAT

Summer Scorcher

It’s Summer. It’s Phoenix. 99% of the time, you could probably say “it’s ridiculously hot” and you’d be spot on. The Phoenix forecast didn’t disappoint as the LOWEST the temperature got at any point was 85 degrees. Even today, it’s incredibly hot even for Phoenix’s standards, as this morning’s low temperature… the LOW temperature was 94 degrees, which broke the record of 91 set back in 2006. In other words.. just stay inside, it’s stupid hot out there. The Weather Channel brought home the win with their incendiary forecast.

Monday: High 107, Low 85.
Tuesday: High 113, Low 89.
Forecast Grade: B

Path of the Derecho

As Ryan mentioned, we’ve been analyzing the forecast and verification of a system that would affect the Northern Plains over the last couple of days, which was kind of all over the place but eventually honed in on during the morning of the event. The NWS put together a pretty neat graphical overview of the event, as taken from radar images of the storm from start to finish as it went from central North Dakota through northern Minnesota:
NDMNDerecho2014

As you can see, the main corridor of severe wind reports followed the northern portion of the derecho as it marched though North Dakota. The southern end got a bit more intense as it moved through Minnesota, and as you can tell, the atmosphere was very capped over SD and southern MN. The southern end made very little progression to the south, while there was plenty of activity on the northern end even away from the main line of storms. So while the forecast took a couple of days to really nail down, and was fairly elusive in doing so until the day of, the SPC got it pretty much dead on, and the radar images prove it as well.

After all that… not bad

Yesterday, I highlighted the lead up to a potentially significant severe weather outbreak in the Dakotas and Minnesota yesterday. It was a little circuitous, and very clear that there wasn’t much confidence or consistency at the SPC for what was going to happen. In the end though, by Monday morning, they had it pretty close to nailed. The thunderstorms developed over North Dakota and congealed into a strong squall line that moved from near Bismarck to Grand Forks and into northern Minnesota. You can see the verification, with storm reports overlaying the convective outlook.
Verifying
So it took a while, but the forecast eventually ended up pretty close to reality. Of course, I need to remind everyone that we also had this less than 24 hours before the thunderstorms actually erupted:

Next time, I’m sure they will nail something down with a little more lead time.

The crazy evolution of a thunderstorm outlook

There is a moderate risk for severe thunderstorms today from the Dakotas to northern Minnesota. How we got to this point is rather circuitous. Let’s take a look at the past 24 hours of SPC outlooks. I don’t think I’ve seen one of these things change so much pre-storm in a very long time. Here is what we started with yesterday morning:

A slight risk, covering most of Minnesota and a lot of the central Dakotas. Furthermore, they had the best threat for severe storms around the North Dakota/South Dakota and Minnesota tri-state.

After a shift change and perhaps the usage of a hallucinogen, Sunday afternoon’s update gave us this moderate risk, with a center about 150 miles to the east-southeast.

And now, thunderstorms were going to be significantly stronger.

Whoa! 45% and hatched, when we only had 30% earlier. And there isn’t much of an overlap, either.

So obviously, something changed, the onus was now on the Twin Cities, St. Cloud and Rochester to be prepared for — Oh, wait. This was the outlook from the overnight.

So we’re back into North Dakota and northern Minnesota, which, initially, wasn’t even in a slight risk for yesterday’s updates. This time, the center shifted about 175 miles to the northwest. Was the threat for significant weather still high? Why yes, yes it was.

Where are we at now with the morning update, you may ask. Pretty similar to the overnight outlook, actually, but greatly elongated.

The only thing is that the threat for strong winds seems to be sneaking back deeper into Minnesota, practically to Wisconsin.

http://www.spc.noaa.gov/products/outlook/day1probotlk_1300_wind.gif?1405956293553

Actually, that’s a pretty significant change, increasing the coverage of significant severe weather like that. There is also a 5% tornado threat now in North Dakota and northwest Minnesota. that really grew over the course of the past two updates.

Expect the afternoon update to push the focus into Iowa.

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