Chase 2009 Day 25 Discussion

[Paul Sherman]

An early Heads Up for Wednesday May 20th and Namely Netweather Chase Team 3's first Chase Day. Very good to see the chance of Supercells be it High Based (But we will take anything we can at the moment) And the forecasts for out here are pointing to Chase Opportunities for Thursday, Friday and Saturday at least at the Moment, granted they are not likely to herald a Tornado Outbreak but Storms Nonetheless!

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0100 AM CDT TUE MAY 19 2009

VALID 201200Z - 211200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

AN AMPLIFIED/BLOCKY UPPER FLOW REGIME WILL CONTINUE INTO WEDNESDAY

ACROSS THE SOUTHERN TWO-THIRDS OF THE CONUS...AS A STAGNANT UPPER

LOW REMAINS IN THE VICINITY OF FL...WITH ANOTHER SLOW MOVING UPPER

LEVEL LOW DEVELOPING NORTHEASTWARD ACROSS THE SOUTHWEST

DESERTS/NORTHWEST MEXICO. FARTHER NORTH...A POTENT SHORTWAVE TROUGH

WILL CONTINUE TO SPREAD EASTWARD ACROSS THE CENTRAL CANADIAN

PROVINCES AND ADJACENT NORTHERN PLAINS/UPPER MIDWEST AMIDST THE MAIN

BELT OF STRONGER WESTERLIES.

...NORTH CENTRAL PLAINS...

AS THE SHORTWAVE TROUGH STEADILY ADVANCES EASTWARD ACROSS THE

NORTHERN PLAINS/UPPER MIDWEST...AN ASSOCIATED COLD FRONT WILL SPREAD

SOUTH-SOUTHEASTWARD ACROSS THE NORTH CENTRAL PLAINS AND UPPER

MIDWEST. AIDED BY THE GRADUAL DECAY OF THE ROCKIES UPPER RIDGE AND

STRONG AFTERNOON/BOUNDARY LAYER HEATING...ALONG WITH LATER DAY ONSET

OF LOW LEVEL POST-FRONTAL UPSLOPE INTO THE HIGHER TERRAIN/FRONT

RANGE...ISOLATED TO SCATTERED TSTMS SHOULD DEVELOP AND INCREASE

THROUGH MID/LATE AFTERNOON...INITIALLY MOST PROBABLE ACROSS

SOUTHEAST WY/NEB PANHANDLE AND THE ADJACENT PORTIONS OF NORTHEAST

CO/SOUTHERN SD. WHILE MULTICELLULAR STORMS CAPABLE OF STRONG WIND

GUSTS/HAIL WOULD LIKELY BE THE DOMINANT MODE...A FEW HIGH-BASED

SUPERCELLS WILL BE POSSIBLE ALONG/JUST NORTH OF THE SOUTHWARD

SAGGING FRONTAL BOUNDARY MAINLY ACROSS WESTERN/NORTHERN NEB...AS THE

STRONGEST SHEAR WILL LAG THE FRONT. THE SEVERE THREAT WOULD LIKELY

BEGIN TO DIMINISH BY AROUND SUNSET AS THE BOUNDARY LAYER BEGINS TO

DECOUPLE.

...NORTHERN MN...

SHOWERS/TSTMS WILL BE POSSIBLE ACROSS NORTHERN MN IN ACCORDANCE WITH

THE APPROACHING SHORTWAVE TROUGH/SURFACE COLD FRONT. IN THE PRESENCE

OF LIMITED BOUNDARY LAYER MOISTURE...00Z BASED MODEL GUIDANCE

SUGGESTS THAT THIS CONVECTION WILL TEND TO BE ELEVATED AND BASED IN

THE MID LEVELS...WITHIN A VERY STEEP LAPSE RATE ENVIRONMENT. WHILE

SOME SMALL HAIL MAY BE POSSIBLE...LIMITED MOISTURE/WEAK

BUOYANCY...AND SEEMINGLY LIMITED POTENTIAL FOR SURFACE-BASED

CONVECTIVE INITIATION ALONG THE FRONT GIVEN THE DEGREE OF

CAPPING...SUGGEST SEVERE PROBABILITIES ARE NOT WARRANTED AT THIS

TIME.

...SOUTHERN FL PENINSULA...

ALTHOUGH MODEL VARIABILITY EXISTS...GENERAL CONSENSUS OF SOLUTIONS

SUGGESTS THAT THE STAGNANT LOW MAY BEGIN TO DRIFT WESTWARD AWAY FROM

THE COAST. AS THIS OCCURS...POTENTIAL WILL EXIST FOR MID-LEVEL

DRYING AND SOMEWHAT STRONGER AFTERNOON HEATING...IN ADDITION TO LOW

LEVEL MOISTENING FROM THE EAST...ACROSS THE SOUTHERN FL PENINSULA.

THIS COULD LEAD TO AN UPSWING IN TSTM VIGOR WITH HAIL/DOWNBURST

POTENTIAL MAINLY WEDNESDAY AFTERNOON.

[stevestorms]

Yehman go and get em, yer got to try and get what there is, look what happened to us last thursday at Lamesa tx :-)

[nsrobins]

Glad to hear you're considering heaidng North Paul on Wednesday and i can now add a bit more detail to my post yesterday about the possibilities up in NW NE.

First up: it's going to be hot - real hot, with surface ts into the mid 90s by 3pm across KS especially. So assuming the aircon is working efficiently, on to the action. The 06 NAM paints a potentially pretty picture of LP high-based sups rolling off the slopes by late afternoon. Moisture looks alright, and indeed a tongue of 57ish dps rides west along the NE/SD border above a dry bulge across the NE panhandle. There's obviously enough shear to turn the updrafts as by 00Z Thurs a slither of up to 3.00 EHI is in place roughly along the moist plume described above. No problem with cap as far as I can see, but will a modest 1250 or so mean CAPE be enough to give the parcels lift? I wonder how much the model allows for topography as the rolling hills of west Nebraska can add a touch of je ne sias que and if you're lucky a beautiful elevated supercell may make the trip worthwhile.

[nsrobins]

18Z NAM: A touch more interesting now, with a firmer moisture profile. Chatting on Stormtrack and the consensus is the moisture will be shallow and mix down to <50F tds by 00Z but you know I'm not so sure. The vertical moisture profile shows sufficient depth I believe to support some high-based storms. Possibly very high based actually but atleast you'll see them from miles away!

I really believe there is enough of an excuse to take the hike up into High Plains country, and a preliminary target based on the aforementioned moisture plume and CAPE, CIN progs and the (theoretical) position of the cold front/'psuedo' dryline axis would take me to North Platte, NE for a late lunch but be prepared to head NW from there if necessary.

Note: I'm still learning this art and will try to introduce other parameters such as Theta E and LCL as and when I fully understand them!

[Gorky]

I'm going to continue my trek out to Yellowstone rather than chase tomorrow. It's gthe sort of thing I might only do once in a lifetime, and there'll be more thunderstorms to come (especially next week if the l12z GFS comes off and the one in progress at the moment seems similar... not to hype up tornado potential as upper winds are not great, but we are back to somewhat zonal extreem cape events which Tour 1 got so many of).

If I was to chase, I'd head to central SD/NE border where the better dews seem to be but I'm not sure you'd make that so you may have to roast it out in the NE panhandle instead. Dews are very meager, but storms fired in this area today under similar circumstances.

[Nick F]

Hi all,

Just checked into our hotel in Kansas for the night even though it is 1.45am in the morning after a six hour drive up from DFW (+ dinner stop).

We will hopefully head up to NW Nebraska to play the slight risk area shown on the day 1 outlook given by SPC this morning:

http://www.spc.noaa.gov/products/outlook/day1otlk.html

[nsrobins]

Hi all,

Just checked into our hotel in Kansas for the night even though it is 1.45am in the morning after a six hour drive up from DFW (+ dinner stop).

We will hopefully head up to NW Nebraska to play the slight risk area shown on the day 1 outlook given by SPC this morning:

http://www.spc.noaa.gov/products/outlook/day1otlk.html

Good to hear you made it safe and sound, Nick. I see Paul K, Sam Hall and team have also arrived and are heading up to the area themselves.

Not surprisingly SPC have upgraded to Slight and I'm slightly more confident now of some Nebraska upslope magic! The whole thing IMO relies on the fact that a DL bulge draws reasonable juice over the top westwards, roughly just behind a rather saggy looking cold fontal boundary.

Good luck all.

[ian cameron]

Hiya guys back home at last am totaly knackered good flight got upgraded :winky: hope you made it to Nabraska will catch up with you all soon

Ian

[Arron]

Goooooood Morning :winky: What a journey! All here safe and sound and now caught up with sleep and ready to chase! Bring it on!!

[dogs32]

hi all.....just got back after a flight delay.truly knackered......

look forward to some pics.....will post up some pics and vids when i have had a sleep

and a truly FANTASTIC TRIP

[stevestorms]

Hiya guys back home at last am totaly knackered good flight got upgraded hope you made it to Nabraska will catch up with you all soon

Ian

How did you get upgraded ???? it was the steak thing wasnt it!!! I have gone to peoples aid 3 times on flights and one was down to our word wether we turned back to london or not and we still got stiffed!!! with a jelly voucher PAH!!! I bet it wasnt AA ??? glad yer back home matey, start saving for next year only 11 months and a bit to go :-)

hi all.....just got back after a flight delay.truly knackered......

look forward to some pics.....will post up some pics and vids when i have had a sleep

and a truly FANTASTIC TRIP

Glad you had a real good time Pat, now yer just gona have to do it all again--and again---and again and---

[WhiteXmas]

Some of these pictures look great!!!!!!!!!! Wish I could see those kind of storms in the "flesh"

[dogs32]

How did you get upgraded ???? it was the steak thing wasnt it!!! I have gone to peoples aid 3 times on flights and one was down to our word wether we turned back to london or not and we still got stiffed!!! with a jelly voucher PAH!!! I bet it wasnt AA ??? glad yer back home matey, start saving for next year only 11 months and a bit to go :-)

Glad you had a real good time Pat, now yer just gona have to do it all again--and again---and again and---

LOL.....i will ..i will...

lovely to meet all of you lot.......a bit sad now..............good time....good storms......

[Ross B]

Hiya guys back home at last am totaly knackered good flight got upgraded hope you made it to Nabraska will catch up with you all soon

Ian

You lucky git! I'm assuming your flight was as quick as ours? 8h 30mins. It seemed short haul compared to the way out...

hi all.....just got back after a flight delay.truly knackered......

look forward to some pics.....will post up some pics and vids when i have had a sleep

and a truly FANTASTIC TRIP

Glad you got home ok mate, i need some sleep as well!

It was nice to meet everyone who was on tour 2 and i had a great time. Good luck to tour 3 now

[Paul]

Streaming is now live:

http://www.netweather.tv/index.cgi?action=chaselive;sess=

[Tom Lynch]

Journey home nearly fine but had tummy bug on arrival at Heathrow which caused me to miss my train at Euston and had to wait 2 hours for the next one. The underground trip from Heathrow was difficult but I was prepared with a plastice bag from Ian, fortunately I managed without using it. The trip north of the train was like a scene from Monty Pythons I shared the table with a drunken bricklayer from Egremont who got drunker the further north we got The carriage was made up of 4 Russian dancers on their way to Blackpool and 30 missionaries from the Church of the Latter Day Saints (Utah). The drunken bricklayer accosted them all. Interesting trip.

As Ian said we got upgraded I strangely enough thought is was a sales pitch and turned it down. However we got it anyway. So Steve there we are and I too am getting my head in order for work tomorrow.

Hi Ross and Pat it was nice sharing our chase together.

Tom

[Nick F]

Gots some cu in front of us trying to go against the cap. Storms further NW over NE Panhandle, but long way from us still 150mph away.

[Tom Lynch]

Gots some cu in front of us trying to go against the cap. Storms further NW over NE Panhandle, but long way from us still 150mph away.

some breaking out north of you

[nsrobins]

Stream is holding together nicely.

Things going according to plan just now - I think you need to get on the 92 at Ogallala and get NW into the action. Could be some great high-based structure in the next few hours and I see the cell on the border is meso warned.

[Tom Lynch]

Gots some cu in front of us trying to go against the cap. Storms further NW over NE Panhandle, but long way from us still 150mph away.

Nick

stuff is severe north of you

[dogs32]

stream is nice and clear guys...

[MAF]

hey Pat, :winky:

you got withdrawal symptoms already?

[dogs32]

hey Pat,

you got withdrawal symptoms already?

:winky: cant wait for next year.got bad jet lag...cant sleep

ive lost the current live stream...