Model Outlook For Chase Team 2

[Paul Sherman]

Will Open this thread on Saturday when we are within the 14 day Range for Chase Team 2 that are Chasing from 9th May.

Nathan and Nick will Also Update this Thread whilst I am away as I might not have too much time on my hands (He Hopes) LOL

Thread will Open at 12z Output from Saturday 25th April 2009

Paul S

[Paul Sherman]

Okay as Promised we now start to Concentrate on Tour 2's First Chase Day namely Saturday 9th May 2009

Obviously this is all VERY Much Fantasy Island at this Stage and Massive Changes will Take Place............But just like Tour 1's Model Count Down here is the 1st Charts to see what It Might be like

- Jet Stream Favours the North Dakota Region but also a Split Flow with Something for Texas Close to DFW

- Plenty Of Energy with Cape Very Nice

- Much more Moisture available over the Texas Region

- Huge Temperatures now into the 30's

- Convective Precip Also Healthy

So In Summary a Good Set Of Charts but as I said this will most probably change Massively but ggod to see if any trends appear over the next 14 Days

Paul Sherman

[Gorky]

1 week to go til team 2 and separately, myself, fly out to the US for more chasing. Just thought I'd look at some of the forecast runs for the first few days.

Firstly, Friday 8th as it appears that there may be some local chasing.

Surface Pressure Shows a low pressure system, with the best upper winds slightly to the north. Probably not a great tornado setup although I'd never rule anything out.

Dews are very high

Resultant Cape is insane with over 5000 cape bullseye around Ardmore and slightly north. The cap is strong on this day, but precip is broken out in southern OK at midnight. Needless to say, any storm with 5000j kg of cape available to fuel them should be capable of dropping insane sized hail.

Saturday looks quieter with biggest threat being in the Arkasnas area. Not sure if this would be worth chasing. Sunday brings another low into the plains. Again upper support is lacking slightly, but there should be storms, Monday is similar also. Beyond this range I'd have no confidence in the GFs, and it's likely things will change considerably before we get out there even with regards to the charts above. The GFS is pretty average up till T240 with regards to the upper air pattern. The ECMWF has a nice trough swinging intowards the west coast at T240 which would be indicitive of a more severe pattern towards the middle part and end of chase 2 if it moved into the Rockies. Again, we are talking a long way out, but I certainly wouldn't complain if that came about.

Edited May 1, 2009 by Gorky

[Ross B]

Thanks, a definite upgrade from yesterdays charts for saturday. I was wondering, is midnight in BST? Therefore its 5/6/7 pm over there?

[Gorky]

Yes, 0z would be GMT time (not BST). Friday is a downgrade this evening looking at it, but Saturday would be a big upgrade, with a 996mb low over the Ks,CO border. Decent dews up to northern Nebraska. A strong cap, keeps things under control until 3z when precip breaks out in Central NE at the triple point. Upper winds are quite strong in this region, so there may well be good speed shear in place Decent cape would yield at least a large hail threat. Given that this is still changing on a day by day basis, I would be not surprised at all if this feature was gone by the next run, but it's all good eye candy.

The ECMWF still has a trough, much deeper tonight just of the west coast of the USA at T240. If that could swing across the US, there would be some good chasing opportunities towards the end of the week after next. Again, the forecast is a long way out and will change... usual caveats apply...

[Gorky]

Some good consistency from the GFS. Both Saturday and Sunday look to be good chase days still, with Western TX/OK/KS being the Saturday threat, into Eastern, OK,KS and into Missouri for the Sunday. Beyond that, the gFS has been flip flopping all over the place with moisture being scoured completely on one run with limited severe potential, so a much more progressive pattern, with several rounds of severe weather traversing the states with a down day or two between each event. I think it's a complete coin toss with the current set up beyond day 7.

[Gorky]

Well, things have flipped once again with Saturday looking a touch moisture starved which would limit severe potential then. Sunday however has become the much begtter day with dews well into the 20's over central ks, in what would be a classic triple point and warm front chase. Strong shear, strong cape, it would be a perfect setup. Of course, I have little confidence in this given how much the models are changing still. I don't think things will fall into place until after tomorrows even when we see how much and how far moisture is scoured from the southern plains.

As far as the medium range models go, ECMWF still forecasts a trough to be sat west of the plains for 3 to 4 days early next week which is very promising.

Some Eye Candy....

Edited May 4, 2009 by Gorky

[Ross B]

Thanks for that, immense CAPE :winky:

What do you think for an off the plane chase on friday? High dewpoints and CAPE are forecast around the Dallas area but i'm not sure whether it can break through the cap? (only had a quick look)

[Gorky]

Given that I am chasing separately, I'll not be able to chase Friday afternoon as I'll be picking up equipment and getting set up so I havn't looked too much into that possibility. There is plenty of cape present, but I'd imagine the strong cap would keep things from exploding on Friday. Perhaps some overnight storms in the area. Again, it'd be worth keeping an open mind till Friday morning regarding this as even the prescence if a few outflow boundaries or a slight increase in forecasted moisture would affect whether any storms formed Friday evening and these things cannot be accurately forecast until the day of the event.

Which flight were you going out on again, btw? May have chance to discuss the possibilities on the flight over :winky:

[Ross B]

Thanks, i guess we will have to wait and see what happens. I wish back of the seat internet was installed on the planes! :winky:

I'm on the same flight as you i think -AA51? The discussion will be pretty one sided, i don't really know much about the American storms yet since this will be my first chase :lol:

[Gorky]

Yeah AA51 for me too. I've just packed all my electrical kit into my Carry on bag. Just need to pack clothes and I'm ready to go. Can't believe it's only a few days to go now. Last year seemed like just a few months ago.

[Paul Sherman]

Well the guys over on Stormtrack are Bigging up the May 11th to May 14th Timeframe as being another possible 2004 or even May 22nd/23rd 2008 Outbreak. One to watch certainly towards the weekend.

Good News for Tour 2 It Seems

Paul S

[Gorky]

Well, Mike H on the Stormtrack forum mentioned this setup, and as a result this mornings runs are terrible. That guy has jinxed everything storm wise he's been on in the last 2 years Lets hope it's a blip and comes back and shows troughing again this evening. It's only 1 run out of the last 5 so I'm not going to get despondent yet, The GFS is looking terrible for Saturday/Sunday now with this current storm forecast to push moisture back to the gulf, and as a result, best threat is pushed back till monday. Still no consistency at all from that model.

Edited May 5, 2009 by Gorky

[Ross B]

Yeah, i saw that

NOAA remaining cautious:

...BEYOND DAY 4...

THE EFFECTIVE SURFACE BOUNDARY FOCUSING TSTMS SHOULD EXTEND FROM THE

SRN PLAINS TO THE CAROLINAS...BUT THIS WILL TEND TO BE LOCATED S OF

STRONG FLOW ALOFT/SHEAR. ALTHOUGH SEVERE STORMS MAY DEVELOP

THROUGHOUT THIS CORRIDOR...UNCERTAINTY EXISTS WITH THE OVERALL

SEVERITY AND PRECLUDES THE INTRODUCTION OF A REGIONAL SEVERE WEATHER

AREA BEYOND DAY 4.

http://www.spc.noaa.gov/products/exper/day4-8/

[Gorky]

Very quick post as the lastest ECMWF charts are out. This returns the troughiness that disappeared this morning, although not as pronounced. The GFs is onboard holding the severest threat off till monday now but looking very good for Monday-Thursday and even well beyond, which is a complete reversal on the dire GFS this morning. Yay for model flip flopping. I'm sure it won't be the last time over the next day or two.

Edited May 5, 2009 by Gorky

[Ross B]

Lets hope we can chase after we get off the plane tomorrow, moderate risk

http://www.spc.noaa.gov/products/outlook/day2otlk.html

I'm leaving for Heathrow in a few hours, staying there overnight tonight

[Paul]

Have a cracking trip mate

[Stuart]

have a good time ross

[nsrobins]

Lets hope we can chase after we get off the plane tomorrow, moderate risk

http://www.spc.noaa.gov/products/outlook/day2otlk.html

I'm leaving for Heathrow in a few hours, staying there overnight tonight

Have a fantastic time - and yes it looks lively friday evening. Talk about jumping in with both feet

[Ross B]

Cheers guys, a tornado after just getting off the plane would be awesome (No pressure team )

[Paul Sherman]

Lets hope we can chase after we get off the plane tomorrow, moderate risk

http://www.spc.noaa.gov/products/outlook/day2otlk.html

I'm leaving for Heathrow in a few hours, staying there overnight tonight

We will be in Full Chase Mode by about 4pm on Friday and Heading up I35 Towards South Central Oklahoma

Paul S

[chionomaniac]

Good luck chase team no 2. Let's hope you hit the ground running!

[multi cellular thunderstorm]

Have a great time Ross, and everyone else on Tour 2.

Looking forward to a model outlook thread for tour 3 soon

[nsrobins]

It'll soon be time for Team 2 to start their tour in earnest and despite the rather hesitant re-grading of today's potential from the SPC (and understandable given the continued presence of a firm cap which has put the lid on the otherwise excellent prospects of the last few days) I think they could be in luck straight from DFW airport this afternoon. In a nutshell, I wouldn't go too far up the I35 as a few discrete sups may be able to break the lid and ride the boundary along the Red River later on.