Sorry for the POS look of the blog, I don't have PS right now; I'll make a new logo and change the look of this thing in the upcoming weeks. At any rate, GFS/ECMWF show an impressive system for this weekend. GFS, as usual, is slightly faster with the progression of the deep-layer cyclone than the ECMWF, but compared to 6-7 runs ago (which placed the sfc low in eastern KS/western MO at 00z) the two models are becoming more in agreement with eachother with the timing of the main shortwave trough aloft. Additionally, the last 2-3 runs of the GFS have been orienting the trough northwest-southeast (negatively-tilted) and more importantly, as said before, slowed it down some. At 00z, it shows the mid-level perturbation impinging the dryline/warm sector; rapidly breaking the cap, initiating precipitation along and ahead of the dryline from central KS into OK. Personally, I don't see much of a difference between this system and 3/23 (which produced several chaseable tornadic supercells in KS and NE) other than, in terms of kinematics, appears to be more favorable. The surface cyclone is projected to be well further south (988mb in central KS at 00z) than the previous system and isallobaric forcing associated with surface cyclogenesis will back boundary layer flow along the dryline. Of course, this yields very favorable low-level shear; with impressive GFS forecast hodographs along the dryline in southern KS/central OK.
In terms of thermodynamics, the GFS has been progging the 55F isodrosotherm into central KS by 00z, with >60 tds into northern OK afterdark as the LLJ strengthens. Forecast soundings show a pretty reasonable depth -- i.e. 75-100mb along the dryline in southcentral KS into northcentral TX. If we can see >1000j/kg of sbCAPE in the warm sector, than Saturday could be an interesting chase day given the extent of the deep-layer kinematic profiles throughout the warm sector.
posted 4:42 PM by Nick Grillo
In terms of thermodynamics, the GFS has been progging the 55F isodrosotherm into central KS by 00z, with >60 tds into northern OK afterdark as the LLJ strengthens. Forecast soundings show a pretty reasonable depth -- i.e. 75-100mb along the dryline in southcentral KS into northcentral TX. If we can see >1000j/kg of sbCAPE in the warm sector, than Saturday could be an interesting chase day given the extent of the deep-layer kinematic profiles throughout the warm sector.
Thursday, January 15, 2009
It's been nearly three years since I've posted here, but I now plan on posting here regularly again since I'll be chasing this spring. I don't have a website up right now, nor am I sure that I'll have one up anytime soon. This blog will be devoted solely to storm chasing and writings pertaining to severe weather meteorology.
posted 1:17 PM by Nick Grillo
Wednesday, April 26, 2006
Sorry for the lack of updates, but there isn't a whole lot to update on weather wise... Other than I haven't chased since the first week of April due to financial restraints -- given that I have decided to save my money for May and June (a wise decision, I would have to think) and even July chasing. Since then, there have been several nice chase days... Including this past Monday in OK and a few other days, including 4-16 in Illinois and 4-15 in Nebraska (the large "Beatrice" tornado) along with the 4-6 tube near Hanover, KS.
My unofficial "leave date" for the Plains is May 7th... The past GFS runs have shown a relatively active second week of May, with the first significant event looking to be around that timeframe -- with the latest GFS showing a large, negatively-tilted trough slamming into the central plains, with favorable low-level parcel trajectories for nice moisture return. I am hoping for a nice mid-May and into June year, just like 2005, but hopefully a few more outbreak days to please us all! :-)
posted 5:16 PM by Nick Grillo
Sorry for the lack of updates, but there isn't a whole lot to update on weather wise... Other than I haven't chased since the first week of April due to financial restraints -- given that I have decided to save my money for May and June (a wise decision, I would have to think) and even July chasing. Since then, there have been several nice chase days... Including this past Monday in OK and a few other days, including 4-16 in Illinois and 4-15 in Nebraska (the large "Beatrice" tornado) along with the 4-6 tube near Hanover, KS.
My unofficial "leave date" for the Plains is May 7th... The past GFS runs have shown a relatively active second week of May, with the first significant event looking to be around that timeframe -- with the latest GFS showing a large, negatively-tilted trough slamming into the central plains, with favorable low-level parcel trajectories for nice moisture return. I am hoping for a nice mid-May and into June year, just like 2005, but hopefully a few more outbreak days to please us all! :-)
Sunday, April 09, 2006
I haven't been able to update for awhile -- and I don't really have a lot to say about last week's (e.g. 30 March, 1 April) chasing -- other than disapointment and a pure waste of time and money. I saw a nice striated supercell in western OK on 1 April, which showed excellent low-level rotation, but the dry boundary layer (large-very large Td depressions and low BL RH) and associated higher LCLs across the moist sector helped to allow for stronger evaporational cooling in the supercell's downdraft, and the storm slowly transitioned from a strong supercell (with tennis-ball sized hail and rotating wall cloud) to a outflow dominant piece of crap -- with linear upscale growth (and merging with other cells to the south).
The setup a few days ago in eastern KS (6 April) didn't look a whole lot different... However, the deep surface low [986mb] almost lured me out to eastern NE hoping for NNW-moving supercells. But, by the 00z NAM run leading up to the event, and then the morning analysis -- everything looks entirely different. I gave a meteoroligical explanation of the "outbreak failure" on Stormtrack here. In shorter terms, the moist layer across the KS/NE warm sector was already shallow to begin with -- and the very strong insolation and convective mixing process during the afternoon helped to mix out whatever shallow moisture we had -- as indicated by the significant hydrolapse right off the surface on the 18z TOP sounding! In addition, the high LCLs (as a result of the shallow BL moisture) and small 0-1km SRH didn't help any for significant tornado potential. I gave a more in-depth look (including a few ob soundings) on that ST topic.
At any rate, I am not sure on when I'll go back out to the plains. Perhaps, I'll leave next (this) week... I have no idea. I was thinking of partnering up with somebody for a few weeks, to unload some of the expenses -- especially with all these 'early season' setups. The GFS continues a progressive flow with another strong trof lifting out of the western US and into the central/northern plains, with the latest GFS amplifying the mean trof to a negative tilt by late next week -- as the wave(s) ride over rather impressive low-level moisture in place over the central/northern US. I don't see ANY signs of this active pattern stopping, period.
posted 1:35 PM by Nick Grillo
I haven't been able to update for awhile -- and I don't really have a lot to say about last week's (e.g. 30 March, 1 April) chasing -- other than disapointment and a pure waste of time and money. I saw a nice striated supercell in western OK on 1 April, which showed excellent low-level rotation, but the dry boundary layer (large-very large Td depressions and low BL RH) and associated higher LCLs across the moist sector helped to allow for stronger evaporational cooling in the supercell's downdraft, and the storm slowly transitioned from a strong supercell (with tennis-ball sized hail and rotating wall cloud) to a outflow dominant piece of crap -- with linear upscale growth (and merging with other cells to the south).
The setup a few days ago in eastern KS (6 April) didn't look a whole lot different... However, the deep surface low [986mb] almost lured me out to eastern NE hoping for NNW-moving supercells. But, by the 00z NAM run leading up to the event, and then the morning analysis -- everything looks entirely different. I gave a meteoroligical explanation of the "outbreak failure" on Stormtrack here. In shorter terms, the moist layer across the KS/NE warm sector was already shallow to begin with -- and the very strong insolation and convective mixing process during the afternoon helped to mix out whatever shallow moisture we had -- as indicated by the significant hydrolapse right off the surface on the 18z TOP sounding! In addition, the high LCLs (as a result of the shallow BL moisture) and small 0-1km SRH didn't help any for significant tornado potential. I gave a more in-depth look (including a few ob soundings) on that ST topic.
At any rate, I am not sure on when I'll go back out to the plains. Perhaps, I'll leave next (this) week... I have no idea. I was thinking of partnering up with somebody for a few weeks, to unload some of the expenses -- especially with all these 'early season' setups. The GFS continues a progressive flow with another strong trof lifting out of the western US and into the central/northern plains, with the latest GFS amplifying the mean trof to a negative tilt by late next week -- as the wave(s) ride over rather impressive low-level moisture in place over the central/northern US. I don't see ANY signs of this active pattern stopping, period.
Saturday, March 25, 2006
GFS continues to support progressive flow opening up over central US by the upcoming early-mid week, with enough upper-level jet energy/DPVA to induce strong cyclogenesis at the surface on WED and THUR -- with both days looking highly chaseable (and possible even FRI) -- with deep, quality boundary layer moisture return into the warm sector. WED looks sweet, with an incredible shear profile (with strongly backed surface flow, veering to the west-southwest aloft at 300mb) and plentiful low-level moisture (55-60 Tds across TX/OK and even into southern/central KS). Still quite a few uncertainties with the placement of the mean trough, but it is indeed safe to say that we'll have a chase coming up next week, and I'll probably leave DTX on TUE afternoon for KS (or OK).
posted 12:51 PM by Nick Grillo
GFS continues to support progressive flow opening up over central US by the upcoming early-mid week, with enough upper-level jet energy/DPVA to induce strong cyclogenesis at the surface on WED and THUR -- with both days looking highly chaseable (and possible even FRI) -- with deep, quality boundary layer moisture return into the warm sector. WED looks sweet, with an incredible shear profile (with strongly backed surface flow, veering to the west-southwest aloft at 300mb) and plentiful low-level moisture (55-60 Tds across TX/OK and even into southern/central KS). Still quite a few uncertainties with the placement of the mean trough, but it is indeed safe to say that we'll have a chase coming up next week, and I'll probably leave DTX on TUE afternoon for KS (or OK).
Friday, March 24, 2006
The GFS continues to bring a strong, kinematically-rich system into the central plains and upper Mississippi valley by WED and THUR of next week, in the midst of impressive boundary layer moisture return into the pre-frontal sector. While the latest GFS run looks less favorable for a "cold core" scenerio in eastern KS on THUR (by bringing the low further north, filling it in quite a bit at the sfc, and backing the mid-level flow). However, I am relatively happy the GFS continually wants to bring a strong system into the picture for next week (for something to chase) -- albeit the inconsistency it (and the rest of the model suite) are having with the placement of this system.
I am very willing to chase this, but I don't like the new run for THUR, with most of the warm sector featuring deep-layered unidirectional flow, with only relatively modest low-level veering wind fields (to yield stronger 0-1km SRH for tornadic potential). At any rate, it could still be quite an event... It just sucks about the flow up againest the warm front, as we could have had a slower-storm-speed version of the 12th, should we get a better wind profile -- as the thermodynamic structure the GFS has been progging is quite simuler to March 12th's system, but with weaker absolute flows aloft to yield slower storm motions further east into the warm sector.
Yeah, I apologize for the rambling about a system +5 days out on the GFS -- but I am quite anxious to chase, and next week holds quite a bit of promise for at least one good day or two.
posted 3:51 PM by Nick Grillo
The GFS continues to bring a strong, kinematically-rich system into the central plains and upper Mississippi valley by WED and THUR of next week, in the midst of impressive boundary layer moisture return into the pre-frontal sector. While the latest GFS run looks less favorable for a "cold core" scenerio in eastern KS on THUR (by bringing the low further north, filling it in quite a bit at the sfc, and backing the mid-level flow). However, I am relatively happy the GFS continually wants to bring a strong system into the picture for next week (for something to chase) -- albeit the inconsistency it (and the rest of the model suite) are having with the placement of this system.
I am very willing to chase this, but I don't like the new run for THUR, with most of the warm sector featuring deep-layered unidirectional flow, with only relatively modest low-level veering wind fields (to yield stronger 0-1km SRH for tornadic potential). At any rate, it could still be quite an event... It just sucks about the flow up againest the warm front, as we could have had a slower-storm-speed version of the 12th, should we get a better wind profile -- as the thermodynamic structure the GFS has been progging is quite simuler to March 12th's system, but with weaker absolute flows aloft to yield slower storm motions further east into the warm sector.
Yeah, I apologize for the rambling about a system +5 days out on the GFS -- but I am quite anxious to chase, and next week holds quite a bit of promise for at least one good day or two.
Thursday, March 23, 2006
The latest GFS has gone wild both kinematically and thermodynamically by progging 55-60 Tds advecting well into KS (and even into NE) on WED and THUR -- associated with a >30kt SW LLJ (which really cranks up on THUR evening), with cyclogenesis at the sfc in response to the approaching amplifying shortwave aloft at H5, with backed low-level flow well ahead of the cyclone on WED. While I haven't been paying in-depth attention to the models constantly, it has appeared the GFS wanted to bring a system onto the central plains during the last few days of MAR since late last week. Some runs being much weaker, some runs being stronger, with this run being quite wild looking.
I am looking forward to the chase season. But, I also have to conserve money. This system is still 6-7 days out, and has been unconsistent from run to run. I sure wouldn't mind spending the rest of APR, MAY and JUN on the plains, living somewhere.
posted 1:39 PM by Nick Grillo
The latest GFS has gone wild both kinematically and thermodynamically by progging 55-60 Tds advecting well into KS (and even into NE) on WED and THUR -- associated with a >30kt SW LLJ (which really cranks up on THUR evening), with cyclogenesis at the sfc in response to the approaching amplifying shortwave aloft at H5, with backed low-level flow well ahead of the cyclone on WED. While I haven't been paying in-depth attention to the models constantly, it has appeared the GFS wanted to bring a system onto the central plains during the last few days of MAR since late last week. Some runs being much weaker, some runs being stronger, with this run being quite wild looking.
I am looking forward to the chase season. But, I also have to conserve money. This system is still 6-7 days out, and has been unconsistent from run to run. I sure wouldn't mind spending the rest of APR, MAY and JUN on the plains, living somewhere.