Model Watch For Tour 3

[Paul Sherman]

I wonder if Nick F Or a few others could update this thread for the arriving guests on Tour 3, changeover day is Saturday 21st May with Sunday 22nd May being the 1st chase day.

Regards

Paul S

[Paul]

Here we go then - tour 3 currently showing to start with some storm risk, with tx and ok looking the higher risk areas for now - convenient for the airport!

Although there's a storm risk, based on this morning's charts the likelihood of anything really is fairly limited as winds aloft will be fairly light.

[D-J-V]

Looks like a good start so far!

I have been looking at TwisterData and Wunderground and DFW has storms forcast for my arrival day on the 20th!!

Although still early days, also need the Jet to get its act together a little bit....still time!!!

Apart from me and the Irish one anyone else coming in on the 20th? There is a Rodeo on that night not far from where we are staying, could be interesting......

[Ross B]

Alison and I will also be arriving on the 20th as well. Pat Timmer will already be there and I think John said he would be there on the 20th too? Just Kim and Terry left after that I think?

[Nick F]

Sunday 21st looking good from 12z GFS at least, 500mb geopotential height/SLP chart for 00z Monday 23rd (18z CDT Sun 22nd) show falling heights from the trough over the Mountain West and a lee surface low over the central High Plains of KS/NE/CO:

Exit of strong jet at 250mb over central/southern plains would create divergence aloft and thus convergence at the surface = storms:

add to this some good moisture return north and thus lots of CAPE:

= severe storms on day 1?

12z ECM maybe has a trough slightly further west over western USA with more in the way of ridging over southern and central Plains, but still scope for some moisture return over southern Plains, but would it be capped?:

So hopefully the slightly more progressive GFS is right ...

[nsrobins]

Both GFS and ECM are keen on developing and holding a cyclonic set-up across the western CONUS from Weds this week, with an attendant increased risk of severe outbreaks on each day going into the weekend and even the early part of next week as short wave disturbances shimmer around the mean low. Moisture return looks substantial, upper air temps look quite low across the middle Plains states indicating that capping issues may not be a problem and although the details can only be ironed-out at closer range I’d say the prospects for the end of Tour 2 and especially the start of Tour 3 look promising.

[DubWeatherAddict]

Good to see we have something to hope for when we arrive so

Just hoping We all get there without any delays now.

Im due into DFW @

7:31 p.m. Flight: CO1467, Via Newark NJ Fri., May. 20,

Im staying in the Grand Hyatt Hotel in the Airport.

Looking Forward to meeting everyone and having a laugh.

Edited May 16, 2011 by DubWeatherAddict

[John Hanrahan]

Ross, are you staying in Irving too? Meself and Mr Vicary are there on the 20th.

BTW, Pat Timmer will only be there if tour 2 makes it back early to DFW. Which is doubtful.

Edited May 16, 2011 by John Hanrahan

[TornadoJo]

Sunday 21st looking good from 12z GFS at least, 500mb geopotential height/SLP chart for 00z Monday 23rd (18z CDT Sun 22nd) show falling heights from the trough over the Mountain West and a lee surface low over the central High Plains of KS/NE/CO:

Exit of strong jet at 250mb over central/southern plains would create divergence aloft and thus convergence at the surface = storms:

add to this some good moisture return north and thus lots of CAPE:

= severe storms on day 1?

12z ECM maybe has a trough slightly further west over western USA with more in the way of ridging over southern and central Plains, but still scope for some moisture return over southern Plains, but would it be capped?:

So hopefully the slightly more progressive GFS is right ...

Hey Nick,

Having a look at the charts myself (and I'm a beginner) I think there's a small chance the cap could break in western Oklahoma on the 23rd. My concern this year is the moisture return. Having been out there on Tour 1 and seen the extensive drought in the western southern plains I am wondering what effect the lack of ground level moisture will have on storm development. The dry line storms I would usually expect to fire in this area failed to develop on each occassion this year. Perhaps the drought is affecting this development? Wondering what your thoughts are on this?

Fingers crossed for the coming week though. Could be good for those lucky enough to be out there!

TJ x

[Ross B]

Ross, are you staying in Irving too? Meself and Mr Vicary are there on the 20th.

BTW, Pat Timmer will only be there if tour 2 makes it back early to DFW. Which is doubtful.

Na, I'm staying in the Grand Hyatt as well(If thats the one in the Airport!) My flight doesn't get in until 7:30pm, but if there are any storms in the area give us a shout and we could rent a car and get an extra days chasing Or drinking :D

Do you mean Pat Timmer (and the Sherminator) making it back for the 20th? Yeah unlikely, there is more of a chance they will be back early'ish on the 21st though? Depends on what the chat is with changeover times this year though.

p.s sorry for venturing off-topic.

[John Hanrahan]

We get in at about the same time Ross. Are you on BA1520 ?

[Ross B]

Afraid not - I'm on AA79 arriving at 19:20. Hopefully get in 10minutes before your flight to beat your customs queue Although DFW was pretty quick with their customs queue last time.

[John Hanrahan]

Hehe. Its well possible you will get in before me as I'm likely to get delayed by her Majesty The Queen in Cork.

[Nick F]

Hey Nick,

Having a look at the charts myself (and I'm a beginner) I think there's a small chance the cap could break in western Oklahoma on the 23rd. My concern this year is the moisture return. Having been out there on Tour 1 and seen the extensive drought in the western southern plains I am wondering what effect the lack of ground level moisture will have on storm development. The dry line storms I would usually expect to fire in this area failed to develop on each occassion this year. Perhaps the drought is affecting this development? Wondering what your thoughts are on this?

Fingers crossed for the coming week though. Could be good for those lucky enough to be out there!

TJ x

Hi, I am sure the acute drought across much of Texas is having an effect on moisture feedback into the boundary layer (surface airmass) through lack of water evaporating into the atmophere from the ground and from plants. But the drought can't be the sole cause of the lack of storms across the southern and central High Plains in particular, as with the right set-up, warm moist tropical air can be drawn up from the Gulf of Mexico across these drought stricken/storm starved areas to create enough moisture for storms and heavy rains.

So obviously there is also some fundamental reason why these set-ups aren't occuring further west over southern and central high Plains and across much of the southern Plains too and instead most storms and heavy rains are occuring further north and east. It appears La Nina is causing frequent occurence of high pressure ridges over the southern Plains and parts of the desert west with the jet diverting further north then plunging SE to the east of the Mississippi. Normally in May you often tend to get SE moving storms across western Texas, New Mexico, Ern Colorado, and OK Panhandle. When I was out in early May 2007 and again in first half of May 2008 we spent alot of time in western and southern Texas chasing SE moving storms and it was much greener than now with lots of colourful flowers. Both those Mays ended up very active across southern and central Plains for tornadoes - especially 2008. And there was no drought in Texas.

There needs to be a big pattern change this month, and there has been talk of this from some quarters, if the southern/central High Plains are to see storms return again, ideally a pattern change that allows a moist upslope flow all the way from the western Gulf of Mexico. Recently any quality moisture return has stayed further east, with most of the severe weather east of the I-35 that runs north from Texas Gulf coast up through DFW, OK City, Kansas City.

Think a big change is on the way though!

[D-J-V]

Not long now,

Models and SPC are indicating good things for Friday, for all those arriving on the 20th lets hope DFW gets slammed and we don't miss out on any of the action!

GFS is showing good temps, CAPE and moisture return for the weekend north of DFW heading into OK area so looks like we may get off to a good start, although not sure how good GFS is around the +90 hour mark....

Anyway better get ready for work.....:huh:

[Nick F]

Those arriving early on Friday may well be treated to some storms in the DFW area, looks like the boundary to drier air from the west and warm moist Gulf air will run NE from SW Texas then N up through Wern Oklahoma and central Kansas - so storms possible to east of this boundary along and west of the I-35 corridor.

Saturday 21st and Sunday 22nd perhaps a similar area for storms, though capping maybe more of an issue by Sunday with strong warm air advection aloft. But I think we could get some SLIGHT risks both days across TX and Sern OK.

Saturday:

Sunday:

Early next week, still a lee low over Ern Colorado and some fairly good moisture return/CAPE across the southern/central Plains, so still opportunities for chasing, upper winds looks strongest across the southern Plains - so maybe some SLIGHT risk days to chase here again, as shortwave troughs eject east and NE across the Sern Plains around the upper trough to the west.

This is based on GFS though and there appears to be some divergence into early next week between GFS and ECM, but will keep you posted.

[Nick F]

Potential for Sunday 22nd, I presume the first chase day for Tour 3, to go moderate risk from Nern TX/Sern OK through Arkansas and Missouri. SPC have 30% probabilities across wide areas from TX/OK up through AR and MO:

http://www.spc.noaa.gov/products/outlook/day3otlk.html

Looking at the kinematics, rich boundary layer moisture accumulating over the Sern Plains with Tds touching 70f, NAM and especially GFS showing some good SBCAPE - approaching 4000 j/kg.

06z NAM wind shear looking particularly favourable for tornadic supercells across Nern Texas and much of Oklahoma atm, though of course these parameters may change by then:

Precipitations progs from 06z NAM and 00z GFS:

Quite a strong cap in place indicated by CINH charts across southern Plains ... but this lid may lend to more discrete tornadic supercells as indications are that storms may be more numerous further NE.

... maybe not to far to go from DFW to get into position for Sunday's chase, though all depends on what happens today adn tomorrow.

[Ross B]

Exactly what I want to hear whilst sitting at the airport waiting to board the plane to dfw cheers nick!!!!

[dallas]

Good news for tour 3,

News Video Blogs Severe Storm Threat Remains for Plains to End WeekBy Bill Deger, Meteorologist

May 20, 2011; 6:12 AM ETShare | .

"Unlike Thursday, several large metropolitan areas will be at risk for damaging storms today."

The risk of severe thunderstorms will persist across the eastern Plains and Mississippi Valley to end the week as a storm system pushes slowly east.

A large portion of real estate extending from southern Texas to eastern Nebraska has the highest chance of getting powerful storms today, similar in magnitude to those which rolled through locations farther west Thursday and Thursday night.

Nearly 70 reports of severe weather were received by the National Weather Service Thursday from Texas to Nebraska, ranging from large hail and gusty winds to a few damaging tornadoes.

While the threat of a tornado or two remains today, the main concerns from the strong thunderstorms will be damaging straight-line winds and hail.

Even without a tornado, a severe thunderstorm can produce wind gusts well in excess of 60 mph, enough to uproot trees and damage property. Hailstones large enough to shatter car windshields will also be possible from some storms.

Unlike on Thursday, several large metropolitan areas will be at risk for damaging storms today, including Dallas-Fort Worth, San Antonio, Tulsa, Topeka, Kansas City, Mo., and Omaha, Neb.

As the storm system responsible for today's storms pushes slowly off to the east, the threat of severe weather will shift toward the Mississippi Valley region later tonight and Saturday.

Little Rock, Memphis and St. Louis, comprising a region already ravaged by severe weather this year, could be battered by powerful storms arriving at the beginning of the weekend.

Unfortunately, the threat will remain into and through the weekend farther west from Dallas to Kansas City as the storm system begins to slow down

From Accuweather

Edited May 20, 2011 by dallas

[nsrobins]

Nearly 70 reports of severe weather were received by the National Weather Service Thursday from Texas to Nebraska, ranging from large hail and gusty winds to a few damaging tornadoes.

From Accuweather

Interesting. I can only see 9 tornado reports thus far, three of which look like the same one. The one report in Colrado caused damage to a buidling.

Hardly 'damaging tornados'.

By my perception Thurs eve was fairly innocuous by the usual standards of mid-May plains storms. Some large hail, hardly a tornado in sight (after another potentially good set-up) so that report is a little 'stretched' so to speak.

Mirroring others I can see the current pattern of set and reset continuing for a while yet and this was well modelled earlier this week. A mean trough ebbing and flowing with recycling moisture return. The action Sat looks more likley AR/MO, with a return to TX/OK on Sunday.

[dallas]

TX/OK would be a good start for tour 3 position wise on Sunday, would nice for them to get some action straight off the bat