2006 Inaugural Chase?
There is alot of chatter about the system approaching next weekend. I'm certainly looking forward to it regardless of the setup. I'm a firm believer of Al Mollar's mantra of "you chase when you can". Since I'm now in a category of being a "hobbiest" chaser, it fits perfectly into my weekend plans (if you're reading this Shane...it's a joke) :-) But, I'd like to offer my opinions based of course on the flippy-floppy models.
I'll use that as my first discussion point. The models are trying to get ahold of the transitional season change right now. They always have a tough time when the upper air pattern starts convulsing and shifting as the sun's increasing angle starts heating and stirring things up in the northern hemisphere. As a result, there are significant differences in the ECMWF and GFS with the latter having a sharper more amplified trough. I want to see a few more runs to see some sort of consistency. For now, I'll play with the 00Z run.
The biggest problems this early in the season are 1) Systems are usually very strong and there is little cap. The result is strong linear forcing and cells exploding all at once into a squall line 2) moisture return is usually shallow and meager and 3) this time of year, the WAA at 850mb ahead of these systems is very strong resulting in thick cloud decks and often vanguard precipitation breaking out all over the warm sector thus killing our instabilities. We often get a good pacific moisture plume thrown into the mix as well with mid and high level cloud decks to deal with.
This system certainly qualifies in all three respects. If the GFS is correct, then the forcing will be strong with little or no cap and strong surface convergence. A good candidate for a squall line. The GFS is showing a typical meager moisture return scenario with surface dewpoints struggling to make it to even 60F...mostly 50's and fairly shallow. High based storms even if surface temps make it into the mid 70's (if they don't, then instability will still be weak with 500mb temps only around -15C). The model is hinting at alot of SW to SSW flow at 850mb naturally being so far south of the forecast surface low position. This will help to scour moisture just ahead of the dryline as daytime mixing ensues and keep moisture shallow. However, this combined with SW 700mb winds might help clear out some of the low clouds ahead of the dryline to get some insolation to aid with lapse rates.
The last thing I see is mostly a unidirectional wind profile as well from 850mb on up...again favorable for squall lines and continuous seeding from downstream cells...especially with the 700-500mb flow being nearly perpendicular to the dryline.
With all of that being said, it has been my experience that the GFS positions surface lows too far north this time of year. Instead of being up in Nebraska, my bet is that it ends up closer to Dodge City if the upper air pattern verifies. That of course will likely change with the next model run. :-) But, a surface low further south would make things more interesting.
I think it is safe to say that we WILL get a system in here by next weekend that will produce severe storms. Even if it is a squall line, those can be pretty cool to chase if they are intense enough. My SDS is pretty bad right now...especially with the prolonged drought we are in. So, I'll be looking forward to it if for no other reason than to escape the DFW metromess and see what convection looks like in person once again. :-) More to come as the event approaches.
I'll use that as my first discussion point. The models are trying to get ahold of the transitional season change right now. They always have a tough time when the upper air pattern starts convulsing and shifting as the sun's increasing angle starts heating and stirring things up in the northern hemisphere. As a result, there are significant differences in the ECMWF and GFS with the latter having a sharper more amplified trough. I want to see a few more runs to see some sort of consistency. For now, I'll play with the 00Z run.
The biggest problems this early in the season are 1) Systems are usually very strong and there is little cap. The result is strong linear forcing and cells exploding all at once into a squall line 2) moisture return is usually shallow and meager and 3) this time of year, the WAA at 850mb ahead of these systems is very strong resulting in thick cloud decks and often vanguard precipitation breaking out all over the warm sector thus killing our instabilities. We often get a good pacific moisture plume thrown into the mix as well with mid and high level cloud decks to deal with.
This system certainly qualifies in all three respects. If the GFS is correct, then the forcing will be strong with little or no cap and strong surface convergence. A good candidate for a squall line. The GFS is showing a typical meager moisture return scenario with surface dewpoints struggling to make it to even 60F...mostly 50's and fairly shallow. High based storms even if surface temps make it into the mid 70's (if they don't, then instability will still be weak with 500mb temps only around -15C). The model is hinting at alot of SW to SSW flow at 850mb naturally being so far south of the forecast surface low position. This will help to scour moisture just ahead of the dryline as daytime mixing ensues and keep moisture shallow. However, this combined with SW 700mb winds might help clear out some of the low clouds ahead of the dryline to get some insolation to aid with lapse rates.
The last thing I see is mostly a unidirectional wind profile as well from 850mb on up...again favorable for squall lines and continuous seeding from downstream cells...especially with the 700-500mb flow being nearly perpendicular to the dryline.
With all of that being said, it has been my experience that the GFS positions surface lows too far north this time of year. Instead of being up in Nebraska, my bet is that it ends up closer to Dodge City if the upper air pattern verifies. That of course will likely change with the next model run. :-) But, a surface low further south would make things more interesting.
I think it is safe to say that we WILL get a system in here by next weekend that will produce severe storms. Even if it is a squall line, those can be pretty cool to chase if they are intense enough. My SDS is pretty bad right now...especially with the prolonged drought we are in. So, I'll be looking forward to it if for no other reason than to escape the DFW metromess and see what convection looks like in person once again. :-) More to come as the event approaches.
posted by Steve Miller TX at 2/26/2006 09:00:00 AM
2 Comments:
LOL, I forget that people actually read my blog sometimes. That was a good one.
I'm one of your regular readers! I'm glad to see that somebody actually reads my blog too. :-)
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