Ominous sign?

[Texas Snowman]

Found this posted by Something Funny on the USA Weather section. Hope it's not a precursor of things to come:


http://news.blogs.cnn.com/2010/04/20/ag ... er/?hpt=T2

Spring storm season off to slowest-ever start

The 2010 spring severe weather season is off to its slowest start on record, according to forecasters from the National Weather Service's Storm Prediction Center in Norman, Oklahoma.

The agency, which is responsible for issuing forecasts for severe storms, releases daily forecasts that predict the level of severe weather and assigns it to three categories - slight, moderate and high.

Typically, severe storms occur most often in the United States during the months of April, May and June.

"It looks like we've gone the deepest into a year without our first MDT (moderate) or high risk," said Rich Thompson, a forecaster at the prediction center. "The previous latest date was March 21, 2005, so we're almost a month past that date."

The 2005 severe weather season got off to a slow start as well, but turned out to be a record-breaking year for severe weather and tornadoes.

Most of the tornadoes that occurred that year were associated with tropical storms and hurricanes that made landfall. The 2005 hurricane season was the worst on record, with 28 named storms, 15 hurricanes and seven major hurricanes –Category 3 or higher on the Saffir-Simpson scale.

[TreasureIslandFLGal]

hahaha! You beat me to it! I was about to post something very similar that showed up on CNN today too. And like you, I saw that 2005 comparison and the fact that this slow start to severe midwest weather is a month worse than 2005's season was. Could that mean that the hurricane season can also be proportionately affected even worse with this even later start date? We'll see!

[brunota2003]

Does someone have a list of dates for the first MDT/High risk for years back? would be interesting to do a study on it

[HurricaneBill]

Didn't 2003 also get off to a slow start?

[wxman57]

I think that one of the main reasons for the lack of spring severe weather in the Plains is the long, cold winter across the Gulf Coast. The Gulf is much cooler than normal, and it is not "opening up". By that I mean that the tropical moisture coming off the Gulf is very limited this year. Tropical moisture is a big part in the development of severe weather. We haven't had a single "low-level jet" situation this spring.

I suspect we'll have an earlier start to the 2010 season, due to the quite favorable shear conditions across the Caribbean and warmer SSTs. The ITCZ moisture is already quite a bit farther north than it was at this time in 2009.

[thetruesms]

I think that one of the main reasons for the lack of spring severe weather in the Plains is the long, cold winter across the Gulf Coast. The Gulf is much cooler than normal, and it is not "opening up". By that I mean that the tropical moisture coming off the Gulf is very limited this year. Tropical moisture is a big part in the development of severe weather. We haven't had a single "low-level jet" situation this spring.

I suspect we'll have an earlier start to the 2010 season, due to the quite favorable shear conditions across the Caribbean and warmer SSTs. The ITCZ moisture is already quite a bit farther north than it was at this time in 2009.

Completely agreed on the Gulf moisture. I think one of the best summaries I've seen of it is a post from one of my friend's blog: http://www.patricktmarsh.com/2010/03/da ... ar-so-far/

It's a month old, but it's about precisely this topic. The blog as a whole is really good - his goal is to have a "one photo per day" blog, but instead of pictures, use weather maps. It can be kind of Oklahoma-centric at times, but there's a lot of really good stuff in there. He tries to make it as accessible to the general public as possible rather than go for very technical, which has its pros and cons, but I think he usually walks the line between too complicated and too elementary pretty well.

[KWT]

I think that one of the main reasons for the lack of spring severe weather in the Plains is the long, cold winter across the Gulf Coast. The Gulf is much cooler than normal, and it is not "opening up". By that I mean that the tropical moisture coming off the Gulf is very limited this year. Tropical moisture is a big part in the development of severe weather. We haven't had a single "low-level jet" situation this spring.

I suspect we'll have an earlier start to the 2010 season, due to the quite favorable shear conditions across the Caribbean and warmer SSTs. The ITCZ moisture is already quite a bit farther north than it was at this time in 2009.

Whats quite interesting is a few mets recently have been suggesting we could see an Atlantic 180 in terms of patterns with the Azores high really powering up towards the summer months and easterly shear really ramping up as a result of that strengthening. Didn't 2007 also get something similar, I mean outside Dean and Felix there was pretty much nothing at all out there of any note, granted those storms did make up for it!

Still with things as they are, I also wouldn't be surprised to see an El Nino type storm early in the season, IE cutoff low heading eastwards....

[Macrocane]

What do you mean by "outside Dean and Felix there was pretty much nothing at all out there of any note" the rapid intesification of Humberto and Lorenzo and the damages caused by Noel and Olga are pretty notable IMO, but if you're talking about strong systems you're right Dean and Felix were the "only" really storng systems.

[KWT]

Yeah thats what I meant, that was probably poorly worded on my part but still, it was a season where outside of Dean and Felix nearly every system got sheared to pieces or were very short lived systems that blew up right before landfall...which of course whilst bad could have been so many times worse!

[Macrocane]

I agree with you, it was a weird season because the ACE did not match well with the number of systems 15/6/2 sounds fairly active but an ACE of 72 is even lower than the 1992 ACE of 75 wich numbers were 7/4/1

[KWT]

The problem was the fact that the hurricanes we had outside of the big cat-5s most didn't last very long as a hurricane but your right it was quite an odd season in that respect...both Majors also being category-5s!

[wxman57]

What's quite interesting is a few mets recently have been suggesting we could see an Atlantic 180 in terms of patterns with the Azores high really powering up towards the summer months and easterly shear really ramping up as a result of that strengthening. Didn't 2007 also get something similar, I mean outside Dean and Felix there was pretty much nothing at all out there of any note, granted those storms did make up for it!

Still with things as they are, I also wouldn't be surprised to see an El Nino type storm early in the season, IE cutoff low heading eastwards....

The ECMWF certainly is not forecasting a strong Bermuda High for July-September. It did correctly forecast the much above normal pressures in the Caribbean and Tropical Atlantic in 2009. This year, it's forecasting the exact opposite:

[Derek Ortt]

I think that one of the main reasons for the lack of spring severe weather in the Plains is the long, cold winter across the Gulf Coast. The Gulf is much cooler than normal, and it is not "opening up". By that I mean that the tropical moisture coming off the Gulf is very limited this year. Tropical moisture is a big part in the development of severe weather. We haven't had a single "low-level jet" situation this spring.

I suspect we'll have an earlier start to the 2010 season, due to the quite favorable shear conditions across the Caribbean and warmer SSTs. The ITCZ moisture is already quite a bit farther north than it was at this time in 2009.

Whats quite interesting is a few mets recently have been suggesting we could see an Atlantic 180 in terms of patterns with the Azores high really powering up towards the summer months and easterly shear really ramping up as a result of that strengthening. Didn't 2007 also get something similar, I mean outside Dean and Felix there was pretty much nothing at all out there of any note, granted those storms did make up for it!

Still with things as they are, I also wouldn't be surprised to see an El Nino type storm early in the season, IE cutoff low heading eastwards....

would be westerly shear. Strong low level easterlies = westerly shear

However, that may affect the steering more as isn't that a deep layer feature? The SAL at the low levels though would create the strong westerly wind shear due to the low-level wind jet

[Frank2]

We haven't had a single "low-level jet" situation this spring.

Last evening Jim Cantore was saying that the sharp trough dropping SE into TX over the next day or two might bring the first true severe weather threat this season, allowing the Gulf to "open up" as you mentioned earlier...

But it was also unusually quiet last season (per Vortex 0, er 2), so this seems to be a continuation of that pattern...

Frank

[KWT]

The ECMWF certainly is not forecasting a strong Bermuda High for July-September. It did correctly forecast the much above normal pressures in the Caribbean and Tropical Atlantic in 2009. This year, it's forecasting the exact opposite:

Yeah, then again note I said Azores high... not the Bermuda High, because I'm not sure you can really class the two as the same high pressure cell. Whilst the models aren't really suggestive of it, from what I've read from some mets, the flipping of various teleconnective signals will be suggestive of a stronger then normal Subtropical belt, esp on the 'Azores side'.

I'd imagine you can have a stronger then normal subtropical belt, esp if its displaced further north and still have a lower than normal pressure in the SW part of the Atlantic basin.

Then again the ECM forecast is also rather assuming we are in La Nina by August/September...which looking at the data we will *struggle* with IMO, esp given we are still holding around 0.8C...which is much higher then we've been at just about any point in other El Nino-La Nina years.

[Dionne]

We haven't had a single "low-level jet" situation this spring.

Last evening Jim Cantore was saying that the sharp trough dropping SE into TX over the next day or two might bring the first true severe weather threat this season, allowing the Gulf to "open up" as you mentioned earlier...

But it was also unusually quiet last season (per Vortex 0, er 2), so this seems to be a continuation of that pattern...

Frank

NWS Jackson, MS is forecasting severe weather for this coming Fri-Sat. The forecast area is central Mississippi. The new color graphics on the opening NWS page shows a red banner across the top of the page with the word "caution". "Warm, moist, unstable air".......with bright green arrows showing gulf moisture inflow.