Posted on 05/21/2013 6:29:09 AM PDT by topher
The Gulf of Mexico's warm air is part of the ingredient for tornado alley in the US. The other ingredient in this mix is cool/cold Canadian air.
The United States was blessed with very few tornadoes in March and April of 2013.
But the United States was going through an extendeded cold spell this Spring.
How cold? Living in Louisiana, the mosquitoes seemed to be blown into the Gulf of Mexico [by a frigid Northernly wind] as fish food most of this Spring. There have been very few mosquitoes bugging us this Spring [so far].
But now the bad news: for the tornado season to start in mid-May/late-May is a very bad thing. Why? Because the days are much longer in late May than they are in late March/early April.
The heating of the sun helps to provide energy for thunderstorms.
Tornado alley is an area where warm air from the Gulf of Mexico streaming North to clash with Canadian air streaming down to the South.
Since daytime heating is longer right now, there is the threat of the tornadoes for a longer period than there would be in late March/early April.
It seems like the days are considerably longer right now than when they were in late March (around Easter Sunday). Hence, a longer day means that more heat is generated for thunderstorms in the afternoon hours.
Without access to the weather data, it is unclear if having longer daytime heating will make these storms stronger.
Apparently, the US Weather Service has been lulled to sleep by the long cool spell this Spring.
Unfortunately, it may have taken the deaths of about 20 school children in Moore, Oklahoma to wake them up...
But it is a fact that thunderstorms are caused by daytime heating. That heating will go on for a longer period of time when the days are longer.
Hence, when Tornado Alley has a late arriving season, red flags should be flying...
Good news this morning. Death toll to revised much lower due to double counting.
Also has plenty to do with cool Canadian air meeting with the gulf air loaded with moisture. Right now it still feels like winter in SD. Forty degrees and the coldest April in years. Oh It’s almost June, and it’s still cold.
http://www.calendar-365.com/calendar/
The length of day on March 31 was 12h 38m. The length of day today will be 14h 38m
The length of day March 31 last year was 12h 41m
The length of day May 21 of last year was 14h 40m
Your hypothesis makes no science sense.
There is a scientific reason for longer days this time of year. It is called “Summer.” But it happens every year, amazingly, at this same time.
Lots warmer here in SW WI, but still too wet to till the garden. Ground is squishy, but not as bad as some years I recall, when it was like walking on Jello.
April and May were both colder than has been the rule for the past 10 years or so, but it is not out of line for what I recall of the 70s.
What is the difference in longer days preceded by cooler weather and longer days preceded by warmer weather.This does not seem to make sense.A cooler spring just means a later start for tornado season, no? The greater heating on longer days is the same.
This guy reminds me of my mother who, as a young girl growing up in the 1920's, couldn't figure out how the May beetles always knew the date so that they could turn into June bugs exactly on the first day of June.
Of course, grandpa would never tell her the secret.
As the sun moves further north during the summer months, the says are longer in the northern hemisphere.
The days are considerably shorter in the southern hemisphere in the summer months.
The short of this: in the summer, the sun travels farther and farther above the equator until the first day of summer is the longest day in the northern hemisphere.
Now, if you put the same kettle on the stove, and heat for 2 hours, the amount of heat the kettle is exposed to is four times as long.
The number of BTU's would vary, depending on factors.
But if the length of the day is 16 hours instead of 13 hours, there are still 3 more hours that the air can be heated by the sun.
The cool air from the north meeting warm air of the south is the main culprit. If it were the length of day time, Alaska would be the center of the universe for twisters.
Tornado alley is an area where warm air from the Gulf of Mexico streaming North to clash with Canadian air streaming down to the South.
A longer day means that there is more potential heat.
I have lived in South Minnesota and I have lived in South Texas.
The summer days in South Minnesota, I noticed are very long -- much longer than South Texas.
I imagine a place like Duluth, Minnesota would have a sunset very late on June 22th and a sunrise very early on the June 23rd. A very short night. And a very long day...
Right. Storms happen when cold air meets warm, moisture-laden air. If we were getting Global Warming, then the North would be warmer, but the tropics would stay about the same. If we get global cooling then the temperature difference between the north and tropics will get wider, resulting in much more violent storm activity.
“It seems like the days are considerably longer right now than when they were in late March (around Easter Sunday). “
Are you sure? Source?
(kidding)
I think the larger part of the poster’s hypothesis is based on the fact that this year, vs last year, the cold has lingered much later into the season. That is surely true in this area (NOVA), where we rarely see 40 degree temps in mid-May, yet last week our temps ranged from 41 (overnight) to one day hitting 82, which is a more typical daytime temp here by mid to late May.
It sure doesn’t feel like Summer. It doesn’t even feel like Spring some days. This year our mid-day high temps have ranged primarily in the 60s. Throw in a couple extra hours of daylight, and the hypothesis isn’t so far out.
From what I could tell yesterday, there was ample warning from numerous outlets regarding the outbreak of severe weather. Yesterday's tragedy is due more to the violence of the storm than any perceived 'sleeping' on the part of NOAA. Nobody was asleep at the switch. It was just a horrible, horrible storm.
Stand by because there’s another cold front heading your way. We’re supposed to see a 15 to 20 degree drop in temps here in Reno overnight so I’m pretty sure that the same cooler air is headed east to meet up with some of that liquified air from the gulf. Mother nature at her nastiest could be rearing her head again in a couple of days in the plains states. If you have a shelter, use it.
Duluth will be in blue since it is known for it cold weather.
Brownsville will be in green since it is known for it warm weather.
Duluth, MN May 21 - 5:27am - 8:43pm Duluth, MN April 21 - 6:11am - 8:04pm Duluth, MN March 21 - 7:10am - 7:22pmDuluth, MN June 21 - 5:14am - 9:06pm
Brownsville, TX June 21 - 6:38am - 8:23pm
Brownsville, TX May 21 - 6:41am - 8:12pm
Brownsville, TX April 21 - 7:02am - 7:56pm
Brownsville, TX March 21 - 7:33am - 7:41pm
Note that Duluth has a day that is about 100 minutes longer on June 21 than Brownsville (~ 1 1/2 hours)
The bottom line here is a simple concept on the surface, that becomes extremely complex in short order.
First think of a real, physical greenhouse. Inside it is moist and warmer when it is cold outside, and somewhat cooler when it is hot outside. It is “moderate” because of the humidity in the air.
Now think of the opposite of a greenhouse, the surface of the Moon. If it is daytime, everything is directly hot. But at night, everything is extremely cold. There is no moderation, no moist air, nothing to block the sunlight nor prevent the radiation of heat back into space.
Now think of Earth’s atmosphere. When there are lots of high clouds, radiation from the Sun gets through but is trapped in the atmosphere, and doesn’t radiate back into space as much. When there are low clouds, more radiation is reflected back into space, so the ground is cooler.
However, when there is little moisture in the air at all, visible or invisible, the ground is more like the Moon, getting hot during the day, but cooling off a lot at night.
This can be very noticeable in the desert, dry air with hot days and cold nights.
There is one more twist to things, that the air over the North Pole seems to be shifting back and forth over the high latitudes, like a beanie on a bald head. When the jet stream goes South into the US, cold air from the Arctic rushes down. But then the jet stream pushes back North on our side of the planet, and rides down on the other side, making things cold in Europe and Russia.
And this is kind of unusual as well, but it is a lot more noticeable when there is little moisture in the air. This is why we had a hard winter and a very long spring.
The big question is why is there less moisture in the atmosphere right now?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.