If you, like me, are interested in tornado activity in America this is the site to bookmark:

http://www.spc.noaa.gov/wcm/#data

This year, so far, looks unusually quiet for both thunderstorm and tornado activity.

The tornado count is less than 10% of average for this time in March, and the last three years have also well below storm activity.

Being NOAA they provide archives back to 1950, which as you can probably guess I have already downloaded and written a viewer for, but I have my work cut out for me with this kind of data, because this site is chock-a-block with all kinds of statistics that I can't begin to match. Because a lot of people die each year as the result of these events (47 last year with 632 injured) NOAA take the whole matter of forecasting and issuing 'watches' for them very seriously.

Why thunderstorm and tornado activity is so low at the moment is debatable, and it will be interesting to see how the rest of 2015 pans out.

On Thursday, March 19, 2015 at 9:21:49 AM UTC, wrote:
If you, like me, are interested in tornado activity in America this is the site to bookmark:

http://www.spc.noaa.gov/wcm/#data

This year, so far, looks unusually quiet for both thunderstorm and tornado activity.

The tornado count is less than 10% of average for this time in March, and the last three years have also well below storm activity.

Being NOAA they provide archives back to 1950, which as you can probably guess I have already downloaded and written a viewer for, but I have my work cut out for me with this kind of data, because this site is chock-a-block with all kinds of statistics that I can't begin to match. Because a lot of people die each year as the result of these events (47 last year with 632 injured) NOAA take the whole matter of forecasting and issuing 'watches' for them very seriously.

Why thunderstorm and tornado activity is so low at the moment is debatable, and it will be interesting to see how the rest of 2015 pans out.

========

There are, as you might guess, several reasons posited. The tornado count has been lower than average during the past three years.

In 2012 a rather persistent high pressure ridge developed across the U.S. interior. In both 2013 and 2014 the early spring was unusually cool across the eastern 2/3 of the U.S., with a western or west-central ridge / eastern trough pattern in place. This was rather persistent during 2014, and can be partly attributed to the anomalous warmth in the eastern Pacific and emerging positive PDO pattern.

With a strongly positive PDO at the moment this sort of pattern is still apparent, and east of the Rockies temperatures have been and continue to be below average. I don't see a significant change in pattern through the rest of March or start of April, so most likely it will stay relatively quiet. Severe storms might be more likely in the S and SE rather than the Plains and Midwest during that period.

Additionally, El Niño - although currently weak - has been shown to have an inversely proportional effect on tornado and severe storm numbers. This has been thought to be the case for a while and now, in timely fashion, there is a paper on the subject:

http://www.earth.columbia.edu/articles/view/3239

http://www.nature.com/ngeo/journal/v.../ngeo2385.html


Stephen.

On Thursday, 19 March 2015 13:56:19 UTC, Stephen Davenport wrote:
On Thursday, March 19, 2015 at 9:21:49 AM UTC, wrote:
If you, like me, are interested in tornado activity in America this is the site to bookmark:

http://www.spc.noaa.gov/wcm/#data

This year, so far, looks unusually quiet for both thunderstorm and tornado activity.

The tornado count is less than 10% of average for this time in March, and the last three years have also well below storm activity.

Being NOAA they provide archives back to 1950, which as you can probably guess I have already downloaded and written a viewer for, but I have my work cut out for me with this kind of data, because this site is chock-a-block with all kinds of statistics that I can't begin to match. Because a lot of people die each year as the result of these events (47 last year with 632 injured) NOAA take the whole matter of forecasting and issuing 'watches' for them very seriously.

Why thunderstorm and tornado activity is so low at the moment is debatable, and it will be interesting to see how the rest of 2015 pans out.

========

There are, as you might guess, several reasons posited. The tornado count has been lower than average during the past three years.

In 2012 a rather persistent high pressure ridge developed across the U.S. interior. In both 2013 and 2014 the early spring was unusually cool across the eastern 2/3 of the U.S., with a western or west-central ridge / eastern trough pattern in place. This was rather persistent during 2014, and can be partly attributed to the anomalous warmth in the eastern Pacific and emerging positive PDO pattern.

With a strongly positive PDO at the moment this sort of pattern is still apparent, and east of the Rockies temperatures have been and continue to be below average. I don't see a significant change in pattern through the rest of March or start of April, so most likely it will stay relatively quiet. Severe storms might be more likely in the S and SE rather than the Plains and Midwest during that period.

Additionally, El Niño - although currently weak - has been shown to have an inversely proportional effect on tornado and severe storm numbers. This has been thought to be the case for a while and now, in timely fashion, there is a paper on the subject:

http://www.earth.columbia.edu/articles/view/3239

http://www.nature.com/ngeo/journal/v.../ngeo2385.html

I thought the start opf the tornado season was identical to the start of the hurricane season on the Pacific coast.

I get the impression the control is how much ice is available for the cut-off to the ITCZ:
https://weatherlawyer.wordpress.com/...h-for-equinox/

If you would like to grab all the available NWS storm reports you can grab huge chunks straight to your download folder in Linux:
Code:


wget http://www.spc.noaa.gov/climo/reports/1402{01..31}_rpts.gif
convert -delay 100 1402*.gif 1402-animated.gif


Copy the line that looks like a URL into Terminal and click, et voila.
Something I got from the Gimp forum:
http://gimpforums.com/thread-backgro...30118#pid30118

This is a good site for forecasting tornadoes:
http://www.metoffice.gov.uk/public/w...ime=1392854400

Just watch out for cyclones going through when there is a Greenland High and another anticyclone to the south east.

The situation required for blocking highs is an intense tropical storm. And the ...well that should set you up.

"I thought the start of the tornado season was identical to the start of the hurricane season on the Pacific coast."

========

It isn't. "Official" East Pacific hurricane season starts 15th May (1st June for the Central Pacific). For tornadoes the "season" is widely recognized as being March through June - the period when tornadoes most frequently occur, although there have been outbreaks in every month of the year. There are far fewer hurricanes outside of their designated season.

Stephen.

On Sunday, 22 March 2015 15:25:44 UTC, Stephen Davenport wrote:
"I thought the start of the tornado season was identical to the start of the hurricane season on the Pacific coast."

========

It isn't. "Official" East Pacific hurricane season starts 15th May (1st June for the Central Pacific). For tornadoes the "season" is widely recognized as being March through June - the period when tornadoes most frequently occur, although there have been outbreaks in every month of the year. There are far fewer hurricanes outside of their designated season.

Odd they are looking at the Southern Pacific cycle. Although it obviously coincides with a lot of detail in North America, the run of the weather in the southern Pacific is south-easterly.

I have always considered the effect most likely to is the Lake Effect. I am sure it is part of tat family of weather phenomena. Such events occur with a Davis Straight/Greenland High and a cyclonic system to the south of that..

The most powerful airstream, at sea level, from such a situation is inland, a contra flow as it were. I'll have to go through my charts and see.

I'm sure that all your advice is well intentioned but I fail to see how a North Atlantic surface pressure chart can help you forecast tornado's?

On Monday, 23 March 2015 08:48:43 UTC, wrote:
I'm sure that all your advice is well intentioned but I fail to see how a North Atlantic surface pressure chart can help you forecast tornado's?

Watch it closely the next few days as the moon drops in the sky and things get cooler. With a propensity to volcanism the spell is very similar to that of tornadic stuff. What you fail to see is that your looking glass is too dark. Ask god to give you more light.

How do you suppose the scientific approach is going to help anyone?

On Wednesday, 25 March 2015 07:40:26 UTC, Weatherlawyer wrote:
An airliner has gone down in the Alps killing 140 people:

https://encrypted.google.com/search?...01.N_lDwHPbsxQ

I got up early this morning after waking up too warm to sleep. Unusually warm weather is a signal in itself that there is a large earthquake due. Over in uk.sci.weather there has been talk for some time about electronic problems interrupting forecasts or data support.

I haven't suffered with anything like that yet, so that's a first (unless you count the annoyance of losing that one chart in the NA_EFS which is hardly on the same scale as a major traffic accident like the above.)

It has been interesting to watch that chart model run functioning as the degree of accuracy improves with closeness yet the chart remains missing. (The 30th shows the chart for the 29th)

http://weather.gc.ca/ensemble/naefs/cartes_e.html
You have to fiddle with the annoying Canadian settings. But what do you expect from a bunch of morons with a national sport where even the bats require bandages?

Further signalling:
List of earthquakes in the medium range is as long as I have seen it in a while.

No significant pair or triple adjacent consecutive events as is normal after a storm. There are a few smaller swarms but following a significant period of Tropical Storms that included Pam, there should have been a more noteworthy closure.

The lunar declination is at maximum north tomorrow which may explain the warmth. There are no strong signals on the North Atlantic chart. Nor is there an report of incidents with ferries capsizing. There was one such news item from 15 March; ten days out of spell.

Personally I was thinking tornadic stuff more likely, from the look of the Southern Ocean. It would be trite to say: "My condolences to the families of the people lost." but one just can't say nothing. Yet, this thread is not the place.

It is rare for such a phenomenon to occur without a companion earthquake of suitable size. However the earthquake signal should have been a cyclone with a slew of occlusions and occluded fronts giving due warning on the western side of the Mid Atlantic Ridge over at least three days with clear dart-boarding.

Instead we got what looked like it could have been tornado signals had the anticyclones remained in place over Greenland.

I never checked the Noon charts output for the North Atlantic. BoM on the other hand seemed quite clear on the subject. Tornadoes -sort of but overlaid on a chart that clearly shows tropical storms or -and it is a big or, something of an interference pattern that takes place every equinox.

What I was doing, besides ignoring everything, was wondering what the name of the next Philippines storm was going to be (it will be Chedeng or Maysak, I believe.) The Mauna Kea observatory model first gave warning of that a few days ago. Today it got serious:
http://mkwc.ifa.hawaii.edu/models/mo...&imgsize=Large

It should be a named storm on the 30th March and be a typhoon later that day or early 1 March 2015. It doesn't look like lasting long, starting cyclosis on the evening of the first or by midnight the next day at the latest. It will be a typhoon until noon on the third reaching the Philippines as a tropical depression.

There seems to be a developing system below it as the data on the chart runs out.

The tornadoes that struck Arkinsaw and Oklahoma last night are on the chart for the 25th which is still showing (Norman time.)

Tornado Reports (CSV) (Raw Tornado CSV)(?)
Time Location County State Lat Lon Comments

2215 WAR EAGLE BENTON AR 3627 9394 PROBABLE RAIN WRAPPED TORNADO. TREE DAMAGE. (TSA)

2230 2 N CLIFTY MADISON AR 3627 9380 (TSA)

2234 4 W SAND SPRINGS TULSA OK 3614 9618 *** 1 FATAL *** EXTENSIVE DAMAGE IN MOBILE HOME PARK NEAR HIGHWAY 51 AND 145 WEST AVENUE. (TSA)

2238 SAND SPRINGS TULSA OK 3614 9611 DONUT SHOP DESTROYED AT HIGHWAY 97. (TSA)

2247 2 S BERRYVILLE CARROLL AR 3634 9357 RAIN WRAPPED TORNADO (TSA)

2335 MOORE CLEVELAND OK 3534 9749 BEGAN 635PM NEAR SW119/PENN ENDED 646PM NEAR SE34/SUNNYLANE ... TIME AND LOCATION EST FROM RADAR. (OUN)

2356 INOLA ROGERS OK 3615 9551 (TSA)

0023 1 N PEGGS CHEROKEE OK 3610 9510 FENCES BLOWN DOWN (TSA)

http://www.spc.noaa.gov/climo/reports/150325_rpts.html

I have just looked at the North Atlantic charts for noon 25 March, 2015 and I would not have given a warning of tornadoes from them. They DO show a pair of anticyclones through which a pair of parallel fronts are running. I would have just warned of two severe medium quakes with a shared epicentre appearing consecutively on the list of quakes:

2015/03/25

06:41 36.38 71.98 5 Mb. PAKISTAN
06:34 39.8 73.5 4.2 Mb. Tajikistan-Xinjiang bor

06:29 43.7 145.9 4 Mb. Hokkaido, Japan region
00:34 42.42 142.98 5.1 Mb. HOKKAIDO, JAPAN REGION

Hardly what I would have suggested.

Still, it is a time of change in the hemispheres. I may not be all that useful as a thaumaturge in the deNada spells but look at the alternative:

https://www.academia.edu/11399518/Te...onst ructions

Lost sheep bleeting quasi-scientific terms as though by their many words they will be heard:
http://biblehub.com/matthew/6-7.htm

On Sunday, 22 March 2015 22:42:13 UTC, Weatherlawyer wrote:
On Sunday, 22 March 2015 15:25:44 UTC, Stephen Davenport wrote:
"I thought the start of the tornado season was identical to the start of the hurricane season on the Pacific coast."

========

It isn't. "Official" East Pacific hurricane season starts 15th May (1st June for the Central Pacific). For tornadoes the "season" is widely recognized as being March through June - the period when tornadoes most frequently occur, although there have been outbreaks in every month of the year. There are far fewer hurricanes outside of their designated season.

Odd they are looking at the Southern Pacific cycle. Although it obviously coincides with a lot of detail in North America, the run of the weather in the southern Pacific is south-easterly.

I have always considered the effect most likely to is the Lake Effect. I am sure it is part of tat family of weather phenomena. Such events occur with a Davis Straight/Greenland High and a cyclonic system to the south of that.

The most powerful airstream, at sea level, from such a situation is inland, a contra flow as it were. I'll have to go through my charts and see.

Damn, I have just realised why tornado spells are so similar to volcanic ones. It is the contra flow. Oddly if you look at the Canadian Arctic chart you will see that the flow is in from the north through North pacific waters somewhere around the Bering Straight. It then joins the easterly flow along the Aleutians.

But on the east coast the air stream must also include an interaction between two systems on the same longitude providing a westerly, snow filled flow over the Great Lakes. In summer that must be getting to the Mid West somehow.

That is where the tornadic stuff comes from. Volcanic eruptions move entire cyclonic systems east. And in the North Pacific a blocking High develops in the Gulf of Alaska (IIRC) or is that for large earthquakes?

It still fails to uncover the cause of course but that is because the cause must cause the course of the no... hang on.... because the cause causes the course...

Ehh.. I've got an idea. Hang on.

On Monday, 23 March 2015 08:48:43 UTC, wrote:
I'm sure that all your advice is well intentioned but I fail to see how a North Atlantic surface pressure chart can help you forecast tornado's?

More help here if I am right. (Negative impact if I am wrong but it will only be wrong if something else occurs too.)

Time of writing: 27 March 2015.

There are three cyclones in a row across the bottom right hand quadrant of the first chart on he
http://www.bom.gov.au/australia/char...Refresh+ View

Such a system indicates either tornadoes or volcanoes. There are two immediate differences that are striking.
1. There is an air gap between the cyclones and the coast of Antarctica.
2. They are in the wrong quadrant for volcanic excesses.

The runs normally start out as small and (for all I know) intense cyclones (the equivalent of white squalls in equatorial regions.) And of course they are accompanied by reports of very cold weather. But I don't recall incidents of cold weather occurring with tornado spells. Except that they did for that system a few days back, didn't they.

I have no idea why a col separates the system when tornadoes are involved/don't when there are volcanic eruptions. And I don't know what the reason is for the choice of quadrant. (I am not even sure that last subtlety exists outside my tiny.)

How hard is all that to grasp I wonder?
And can I choose my words more carefully without resorting to babyspeak?

On Thursday, 19 March 2015 09:21:49 UTC, wrote:
If you, like me, are interested in tornado activity in America this is the site to bookmark:

http://www.spc.noaa.gov/wcm/#data

This year, so far, looks unusually quiet for both thunderstorm and tornado activity.

The tornado count is less than 10% of average for this time in March, and the last three years have also well below storm activity.

Being NOAA they provide archives back to 1950, which as you can probably guess I have already downloaded and written a viewer for, but I have my work cut out for me with this kind of data, because this site is chock-a-block with all kinds of statistics that I can't begin to match. Because a lot of people die each year as the result of these events (47 last year with 632 injured) NOAA take the whole matter of forecasting and issuing 'watches' for them very seriously.

Why thunderstorm and tornado activity is so low at the moment is debatable, and it will be interesting to see how the rest of 2015 pans out.

AGW deviousness at work for all to see, or not see in this case.