More Thoughts as we head into Chase Season:

[Jeff Miller]

As the new hydro outlooks were issued today, I was taking a glance at the current moisture projection here, and could not help but make some observations:

It seems to me on a casual glance that we have the makings of a very active spring season. Here are my thoughts:

Persistant drought conditions in western New Mexico, Arizona and California should create low dewpoints and very dry air advection in these areas. At the same time, high levels of moisture due to an active season over the Plains (Texas especially, as many parts of Texas have been deluged with heavy rains) will increase the dewpoints in these areas, especially as the foilage blooms and greens in these areas.

A second area of drought conditions will produce dry air as well over Wyoming, Western Nebraska and Western South Dakota. And as is the case down south, there has been heavy snowfalls in the latter part of the winter in these same areas which should provide more than sufficient moisture for evapotranspiration as the season wears on.

These two factors ALONE indicate to me the potential for significant dryline setups in both the southern and northern plains as the dry air from the drought stricken areas advects east into the moist air from both gulf return and soil moisture. These indicate to me what is unavoidably a far different setup then last year no matter how you slice it.

I am just focusing on this element - unusually dry air due to drought conditions in the west with quite moist air due to frequent and precipitable systems in the Plains.

I am seeking opinion as to the other elements that could interact with the potential dryline activity that the above graph indicates - and if your opinion has changed one way or the other about the upcoming season in a forecast perspective. I am also seeking opinions on if there is expected to be a change in the overall storm track - currently being intense southern stream systems - what one would expect to see this time of year. And as an aftertought: With the abundance of dry air available to the west, should we expect to see more LP variety storms this year in your opinions.

 

[JF Massicotte]

Your theory is interersting. I was already forecasting higher moisture for the plains but I did not think about drier air to the west.


I am still a newbie in forecasting but I like the idea of drier air encountering moister one while I am going in the Plains this year.

 

[Jeff Miller]

A basic element for severe weather in the plains is the dryline.

Basically this is just a check into thoughts and opinions of others as the season begins to evolve looking at one small piece of the puzzle.

 

[Mikey Gribble]

I don't think you can say one way or another if we are going to have more LP storms based off of long range synoptic scale projections.

 

[Jeff Miller]

I don't think you can say one way or another if we are going to have more LP storms based off of long range synoptic scale projections.

Totally agree. Perhaps that question was more than a little off base and I wasn't totally clear on the intent. Trying to phrase questions as I intend them to be while on lmy lunch break at work is not easy to do. I should wait until I get home

 

[Kenny Drake]

Well.. I hate to compare what I have noticed to last year since last year was horrible for storm chasing (in the southern plains particularly).

2006:
-Major rain event during spring break across OK/TX
-Very dry in the SW
-Drylines pushed well east (Missouri/Arkansas/east TX)

So far 2007:
-Major rain event last week (week before spring break)
-Projected to be very dry in the SW
-Dryline progression?

 

[David Drummond]

Well.. I hate to compare what I have noticed to last year since last year was horrible for storm chasing (in the southern plains particularly).

2006:
-Major rain event during spring break across OK/TX
-Very dry in the SW
-Drylines pushed well east (Missouri/Arkansas/east TX)

So far 2007:
-Major rain event last week (week before spring break)
-Projected to be very dry in the SW
-Dryline progression?

What your forgetting though was the 2005/2006 winter was darn dry across the southern plains. When we should have been having snow/ice storms we were having sandstorms and prairie fires.

Not so this last winter 2006/2007. There were regular wetting events, some heavy across the southern plains.

So while there was one ok rain event in 2006, we have been getting regular wetting events since september or so last year now.

 

[Charles Kuster]

Dr. Greg Forbes did talk about this element at the Storm Chasers Convention in February. He mentioned that last year, there were extreme drought conditions in Oklahoma, Kansas, and Texas and this may have caused the dryline to progress further east (MO, AR, etc.). This year, the drought areas are further west (Wyoming, west Nebraska, and SW Texas). He mentioned that central to eastern Nebraska and east Texas may see enhanced storm activity due to the potential position of the dryline.

It is very hard to say anything definitive about the upcoming season right now, but I do think that the lessening of the drought in the plains can't hurt our chances of at least having an average spring season. As for the LP storms, I think supercell mode depends more on winds at the upper levels instead of the dry air near the surface. I might be wrong though?? Good luck to all this season!

 

[Mike Hollingshead]

If the drought and wet theories held any real merit you'd think dry areas would stay dry forever and wet ones would stay wet. If a front blasts east, is that because the ground was dry? I think if one can keep a favorable gulf pattern long enough, it won't really matter how dry any ground is on the way north. If a crappy pattern is in place, screwing the gulf time after time, then we can blame the crappy storms on that dry ground if it is around. Last sentence was a joke.

 

[Verne Carlson]

Here's the link to Dr. Forbes talk that Charles mentioned. Very much along the lines of what Jeffrey is speculating:

http://www.weather.com/blog/weather/8_11771.html?from=blog_permalink_mainindex&ref=/blog/weather/

 

[Ray Walker]

I dont know about drought having a main impact on the dryline. Ya I do think it has at least some impact on how the boundary will move, however last year and back in 05 we had systems that were extremely powerfull. Were talking about 985mb lows!!!! I think the more a system deepens and the powerful upperlevel winds have something to do with dragging the dryline further to the east. Also if you remember in 05 and 06 the may and june timeframes didnt have much in the way of nice troughs and systems to move into the southern plains to set off storms or tornadic storms.

Thats my opinion.