Dan Robinson
Just give me a 1995 and I'll wait patiently for June.
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Stan Rose
EF5
Can't be any worse than last year, so Im ready for a big season! Last year moisture was definitely an issue. I'm already ahead of my snowfall for all of last winter, and at least some of the 1-10 ft of snow that is still covering the E CO plains is gonna hang around a while, so that's good news.
Mark Farnik
EF5
Let me first explain what made last year the storm chasing super turkey it was, and then explain what makes me so optimistic about the chase potential this year.
Like Stan mentioned, last year moisture (or the lack thereof) was a serious issue. But what was an even bigger issue, especially in the western Great Plains, was the constant wind. It was the windiest and warmest winter and early spring anyone around here remembers, I think we only had maybe two dozen days at most between November and May where the wind wasn't blowing and we had only 22 inches of snow between October and April at our farm; our 'normal' snow total is around 55 inches.
What the wind did was completely dessicate the soil profile, and since there was no moisture to replace it, every time the wind blew it kept sucking more moisture out of the soil. We had to dig out a hydrant in late April, and we discoverd that the soil profile was bone dry until you got
5 1/2 FEET DOWN! This lack of moisture kept the grass from greening up in the western High Plains until almost June and prevented farmers from planting many of their crops because there was no moisture to sustain them. You ask, what does this have to do with the abysmal chase season last spring/summer? Everything.
Most everyone here is familiar with transoevaporation. In a normal year, the peak heating evapo-transpiration from the grass, crops etc. and from the soil itself help increase the dewpoint values by 5-10 degrees during the mid to late afternoon hours. The problem is that because of the combination of the constant wind and the lack of moisture, the entire Great Plains soil profile was Atacama desert dry, the grass greened up two months late, and a lot of the crops (wheat, triticale, grain sorghum, etc.) which normally would have been providing daytime evapo-transpiration hadn't been planted. This in turn resulted in lower dewpoints/higher LCL's all season long, which made it next to impossible for tornadogenesis to occur even in the most fantastic shear and forcing setups. Also the soil temperature was far warmer than it normally would have been, which helped create the 'unbreakable' caps which resulted in the many bust situations we endured last year.
The wind, warmth and abnormal dryness of last winter was directly responsible for making 2006 the terrible chase year that it was.
This winter, at least thus far, is a completely different animal from last year. At our farm, I've recorded 34.5 inches of snow since October, which is already one and a half times as much snow in four months as we accumulated in seven months last year. At this point it appears the storm/jet stream track we've been seeing since the middle of December is going to continue to persist across the Southwest/southern Plains through at least March, if not longer. I totally agree with Jason; If this pattern does persist, I can say with a fair amount of confidence that the Southern and Central Plains will likely see some awesome outbreaks at least through late spring. It's a little too far out to speculate reasonably about the summer months, but I can say this: if we continue getting good moisture the rest of the winter and into this spring, and the farmers are able to plant the crops they couldn't plant last year, and the grass greens up when it's supposed to, the evapo-transpiration from those crops and that grass is going to play a significant role in raising dewpoints/lowering LCL's during the late spring/early summer, and at the very least increase the chances of tornadogenesis occurence.
I, as much as the rest of the ST community, am painfully aware that a lot of things could change between now and spring; in recent years there has been so much variability from season to season. There is no single, established long term weather pattern which we can use for reference and guidance, but rather a plethora of smaller patterns with one or two distinguishing features and a host of variables which can be present in several different patterns, which can fool us into believing we're in one weather pattern when we're really in another.
About all that we can do is attempt to identify the primary pattern indicators, using prior experience and knowledge from which we can put forth our best guess as to what variables will occur within the main pattern. When the variables manifest themselves, then, and only then, can we can make a truly informed forecast. That's meteorology for you.
I have a gut feeling that 2007, if anything, will overcompensate for 2006. It seems that in meteorology, as in life, things tend to swing from one extreme to another, and amidst the chaos caused by the respective extremes, perfect balance is achieved.Last edited by a moderator:
Brian Stertz
EF5
Good points Alex....also it remains to be seen if historical winter weather events carry over into the following spring. It looks like the High Plains north of a Roswell NM to Abilene TX line have seen a good deal of moisture...well up into the Rockies and Sangre De Christos. I would think certainly this will certainly keep the out of control hell caps to develop/spread out as early as they have been. Plus one more thing to throw out was how severely veered the low level jet was last year. This year I am seeing less of that showing up. Maybe this spring we can get back to a consistent lee cyclogenesis pattern instead of the surface lows wrapping up over/east of the Mississippi Valley.
Andrew Pritchard
EF5
Also remember though, May 2003 was basically only May 1-10th, and even more specifically the 3rd through the 10th. With the exception of that week, the 2003 season was relatively quiet in most places.
Verne Carlson
EF5
The CPC is out with it's 3 month outlooks which take us through April 2007. It looks like above normal precip and near normal temps are expected in the southern plains. Let's hope it has the effect of giving us a normal chase season in May and June.
afischer
EF4
2003 was ridiculously active from Apr 15 thru May 10 w.r.t. the sheer number of progressive shortwave trofs acting on (primarily) abundant BL moisture. Several events were tough to chase and/or weren't necessarily prolific tornado producers, but I saw gads of gorgeous/vicious supercells during that period. June also had four nice Plains events, including the "obscure" June 24th set-up that I was unable to chase.
Back OT, I have high hopes for a few nice southern Plains events in Spring 2007 (based on the active southern branch and recent drought relief).. including a couple in OK. I've only chased in OK maybe three times, and have never seen a tornado there.Last edited by a moderator:Mickey Ptak
EF5
You know I am in the same consensus with most of the other post about the optimisms about the 2007 season, especially in regards to the Southern Plains states (OK and TX to more direct).
Back in Feb 2006 while at one of Rocky’s chase parties, I overheard Rocky telling Shane that he was very concerned with how the ongoing 2006 drought would effect the upcoming 2006 season in regards to limiting moisture due how dry the soil had become. Rocky, IMO, was right on the money with his concerns I have no doubt. Also Mark Farnik wrote, in his earlier post for this topic, how much transevaporation really effects the Td’s in a synoptic scale. IMO, 2006 proved how effective transevaporation / soil moisture effects a potential setup.
Now it goes to prove that even when you think you have it figured out, talking with a chaser, like Rocky, who has 20+ years of chase experience under his belt proves a very educational experience. I had simply never thought about transevaporation and quality soil moisture, and the funny thing is I don’t know why I didn’t. What he said about the drought (soil moisture) made such perfect sense. Kind of like a Homer Simpson moment, D'OH!!
Anyway, I agree that the 2007 will be much improved in regards to more opportunities down here in OK and TX as long as we keep this pattern up (although I wish it would just be rain rather than snow and ice). However, an active winter does not predict an active Spring. At least we have some assurance that, maybe, we can some-what rely on soil moisture to help raise those Td’s, lower the LCLs and CAP strength. Those low Td’s and high LCLs are good for the Caprock of TX though (in which I am now hooked on when it comes to those setups).
We will see…
MickLast edited by a moderator:Mike Hollingshead
I'm not sure 2006 was given the chance to see what the drought would do to things. That massive, stuck, east coast trough after May 9 surely had a worse effect than any drought in place(with its offshore flow). Moisture was making it's way north well enough in March and April wasn't it(relatively speaking)?
As for 2007, I hope we get out of this cut off pattern by April.Mickey Ptak
EF5
Ya Mike there is far more to the 2006 bust than just simply moisture, but for the few chances we had here in the SP it sure hurt us in a big way.
If I recall by my research for the Storms of 2006 (get your copy today!) project, both March 12 2006 and April 15 2006 were low 60 tds yet very shallow. With those two days at hand, and as much shear as we had, even those somewhat high based supercells had plenty to work with. IMO Those conditions would have never worked had it been down further south into OK and TX.
But that is just my opinion.
Mick
scott r currens
EF3
First off, I want to say that I have no idea how active the 2007 chase season will be. In the end my 2007 chase season will come down to how well I do on a hand full of chase days, not how good the entire season is.
As a rule I like to see above average precipitation on the High Plains, Texas, and the SW states. When these areas are relatively moist into late May and June it tends to delay the summer death ridge. I believe to some extent synoptic ridging and troughing are influenced by vegetation and soil moisture especially during late May and June. Is it a coincidence that in 2004 most of Texas had above average precipitation totals and the ridge of death never shut down the Plains? I don’t want to get into in “chicken or the egg†argument because I don’t care what came first, as long as the ridge of death stays away until late June or July.
nickgrillo
EF5
IIRC, 3/12/2006 had relatively deep moisture, especially for early March in the Midwest US. IIRC, the RUC-2 proximity soundings surrounding the "six-state supercell" had low-level moisture layers mostly ~75-100mb in depth, throughout much of it's lifespan. On the other hand, 4/6/2006 and 4/15/2006 had very shallow moist layers, with the 18z TOP sounding on 4/6/2006 having a hydrolapse no more than 10-25mb above the surface...
I have no idea how good the 2007 season will be, but I can only imagine it will give more opportunities than the 2006 spring season did. I'll be ready to take my annual trips out to the plains.
Brian Stertz
EF5
I've got no problem with this pattern so far to be honest. We are seeing more typical C/S Plains precip events, and the strength of these decently progressive systems remains pretty much carried over from the Pacific to the Plains. Lets hope for a good lee-side cyclogenesis pattern this spring. Killer elements to a good spring severe wx season are deep troughing into the N/C Gulf, strong cold front passages north-south across the Plains & Midwest, badly veered low level flow, and as last year set up, a VERY nasty drought in the High Plains. I do not see much indication of these killer elements so far...and with a healthy southern branch...I do not see this being something to negatively impact the season coming up. As Scott mentioned though, 90% of the battle is maximizing one's opportunities during the events that come our way. It also means being patient and really studying the weather. Last year I think everybody pretty much put "spitwads on the ole' chalkboard". I know I did...and this when I chased less than 10 times last spring. Thank goodness for that great SD event in September !!
Terrence Cook
EF2
I have read alot of research about the effects of high and low soil/vegetation moisture. Although I can't find them now to include the titles, authors .
But I believe that it's impact is significant and easy to observe. Especially in corn belt areas, a large expanse of wet soil/crops seems to have the ability to even turn an LP or classic supercell closer to HP and increase water loading.
I don't want to start a diff. conversation about sup's but the impact is definetely there. But all of us know that there are (many) other factors to include.
Drought relief in the southern plains does encourage me to go chasing more often in the end.Dan Robinson
How much of a factor is evapotranspiration in the whole of the boundary layer? I knew it could create significantly higher DPs in a very shallow layer close to the ground, but I understood when it came to actual convection, it was fairly inconsequential when compared to the ambient moisture depth and was usually mixed out easily and quickly during the day. IE, if you already had a shallow layer of 60s or deep layer of 50s, ET wasn't going to help much in the short term. In the long term, maybe, with many days of ET to 'charge' the boundary layer?
I also didn't think dry ground could have much detriment as long as you had strong return flow - but I could be wrong. I remember back in 05' when there was a big fear that all the tornadoes would be big, un-photogenic dusty debris clouds because of the dry ground, with any condensation funnel buried inside. Thankfully we didn't have that problemLast edited by a moderator: