Chase Discussion Day 17

[stevestorms]

Glad the software has arrived.

I'm still in the panhandle down in Silverton, and will make a decision on today by 5pm local time, there are still a few question tomorrow regarding warm sector activity which is keeping me from ditching today right now to position. I've stocked up on energy drinks if I need to drive until late tonight

Some Vortex2 team members have just shown up here OK make that a convoy now...

cheers Nat, good luck

[Gorky]

Just lost cloud cover here 40 mins ago and it is now HOT HOT HOT. Very uncomfortable sat in the car right now

[NL]

Latest from the SPC.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0259 PM CDT TUE MAY 12 2009

VALID 122000Z - 131200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN HIGH

PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN CENTRAL PLAINS EWD

INTO THE MID MS VALLEY...

..THERE IS A SLGT RISK OF SVR TSTMS IN CENTRAL/SRN FL PENINSULA

..CENTRAL/SRN HIGH PLAINS

WARM FRONT WAS LIFTING RAPIDLY NWD THROUGH THE TX PANHANDLE/SWRN OK

WITH CLEARING SKIES AND WARMING TEMPERATURES. UPPER WV IN FAR SWRN

TX HAS INITIATED CONVECTION OVER SERN NM AND EXPECT STORMS WILL

DEVELOP/SPREAD NEWD INTO WRN TX THIS AFTERNOON/EVENING. OTHER HIGH

BASED STORMS MAY SPREAD INTO ERN CO/WRN KS THIS AFTERNOON FROM CO

HIGHER TERRAIN. ONCE STORMS MOVE INTO MORE MOIST BOUNDARY LAYER...

DEWPOINTS IN THE 50S AND LOWER 60S...MUCAPES AROUND 3000 J/KG SHOULD

BE SUPPORTIVE OF SUPERCELLS WITH HAIL/WIND THREAT. STORMS MAY

STRUGGLE TO MOVE VERY FAR EWD INTO KS/OK WHERE CLOUDS/COOLER

TEMPERATURES WILL PERSIST THROUGH THE LATE AFTERNOON HOURS.

..CENTRAL/SRN FL PENINSULA

DESPITE VERY WEAK ENVIRONMENTAL WINDS...THE COMBINATION OF SWD

MOVING COLD FRONT...MLCAPES AROUND 3000 J/KG AND 500 MB TEMPERATURES

AT -10 TO -11C WILL BE FAVORABLE FOR STORMS WITH HAIL/WIND DAMAGE

UNTIL ABOUT 00Z. A SLIGHT RISK HAS BEEN ADDED TO THE AREA.

..IL

STRONG LOW LEVEL WARM ADVECTION...CURRENTLY MAINTAINING CONVECTION

FROM NERN AR NWD INTO ERN NEB...WILL SPREAD NEWD THROUGH THE PERIOD

AND STRENGTHEN TONIGHT AS LOW LEVEL JET SPEEDS INCREASE TO 50-60 KT.

EXPANDED THE SLIGHT RISK NEWD INTO IL FOR TONIGHT AS FORECAST

SOUNDINGS INDICATE MUCAPES FROM 1000-1500 J/KG AND EFFECTIVE SHEAR

AT 40-50 KT...WHICH WOULD BE FAVORABLE FOR HAIL.

..SRN NEW ENGLAND

STRONGER CONVECTION HAS WEAKENED AS DRIER AIR AS MOVED INTO THE

REGION...WHICH SHOULD END EARLIER THREAT FOR BRIEF SEVERE WEATHER.

..SRN AR/NERN LA/WRN MS

BAND OF STORMS WERE MOVING SEWD ALONG INSTABILITY AXIS TOWARD NERN

LA/WRN MS. THOUGH ISOLATED WIND/HAIL THREAT IS POSSIBLE...

RELATIVELY WEAK SHEAR AND WEAK LOW LEVEL JET INDICATE HEAVY RAINS

WOULD BE THE PRIMARY THREAT.

..IMY.. 05/12/2009

[nsrobins]

Convection firing in eastern CO, despite the lack of official guidance or statements I am expecting a PDS to develop now in western KS after 23z. Would suggest Scott City to Gove for intercept.

I don't think the SPC are that keen on either of our targets, Roger, but I'm going to try to understand the philosophy behind your argument as I need to learn and if you can't make the most of May synoptics in the Plains you've got the wrong hobby.

I assume that subtle shortwave ripple has initiated the convection on the NM border. It's strange when you've spent quite a bit of time during the day studying models to see your plans unfolding before you (or in my case dissolving before you probably)

[NL]

Cells sw texas tracking NE about 80 mile from Big Spring have sprung to

life in the last 25-30 mins.

[nsrobins]

Mini-turrets going up near Sweetwater. Still not sure why things arn't progressing in the Panhandle but it's still an hour or so from the predicted cap dissolution.

[NL]

Severe potential and possible WW issued by SPC.

MESOSCALE DISCUSSION 0804

NWS STORM PREDICTION CENTER NORMAN OK

0343 PM CDT TUE MAY 12 2009

AREAS AFFECTED...PORTIONS OF W TX INTO THE PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 122043Z - 122145Z

THUNDERSTORM INITIATION IS POSSIBLE DURING THE NEXT SEVERAL HOURS

OVER PORTIONS OF SWRN/WRN TX INTO THE PANHANDLE. THIS AREA IS BEING

MONITORED FOR A WW.

SUBJECTIVE SURFACE ANALYSIS INDICATES A WARM FRONT LIFTING NWD

THROUGH W TX IN RESPONSE TO AN APPROACHING UPPER LEVEL TROUGH OVER

THE PAC NW/NRN ROCKIES. THE FRONT IS EXPECTED TO CONTINUE RETREATING

N THROUGH THE EVENING AS LOW LEVEL STRATUS OVER THE TX PANHANDLE/WRN

OK ERODES AND SURFACE LOW PRESSURE DEEPENS N OF THE REGION.

MEANWHILE...STRONG DAYTIME HEATING OVER ERN NM/FAR W TX HAS RESULTED

IN TEMPERATURES CLIMBING THROUGH THE 80S AND INTO THE 90S...AIDING

IN THE DEVELOPMENT OF A WELL MIXED BOUNDARY LAYER. COMBINATION OF

DESTABILIZING LOW LEVEL AIRMASS AND APPROACH OF WEAK UPPER LEVEL

IMPULSE EMANATING OUT OF MEXICO/FAR W TX/SRN NEW MEXICO HAS RESULTED

IN THE DEVELOPMENT OF HIGH BASED CONVECTION INVOF ROW AND HOB NM SWD

TOWARD FST IN TX. AS THIS ZONE OF ASCENT CONTINUES MOVING ENE INTO W

TX AND ENCOUNTERS INCREASING BOUNDARY LAYER MOISTURE...HIGH BASED

STORMS MAY DEEPEN AND INTENSIFY.

INITIAL HIGH BASED ACTIVITY SPREADING E THROUGH ERN NM AND SW TX MAY

INITIALLY POSE A DAMAGING WIND THREAT...GIVEN THE HOT/DRY WELL MIXED

LOW LEVEL AIRMASS. FARTHER E...RUC FORECAST SOUNDINGS INDICATE VERY

STEEP MID LEVEL LAPSE RATES RESIDE ACROSS THE REGION...AND WHEN

MODIFIED FOR AREA SURFACE CONDITIONS...YIELD MLCAPE VALUES IN EXCESS

OF 2000 J/KG. MID LEVEL FLOW IS NOT PARTICULARLY STRONG /AROUND 30

KT PER TCU PROFILER/...BUT VEERING WIND PROFILES COMBINED WITH THE

LARGE CAPE/STEEP LAPSE RATE ENVIRONMENT WILL FAVOR ORGANIZED STORM

DEVELOPMENT...INCLUDING POSSIBLE SUPERCELLS. SURFACE OBS AND RUC

SOUNDINGS SHOW LARGE TEMPERATURE/DEWPOINT SPREADS RESULTING IN

FAIRLY DRY BOUNDARY LAYER OVER MUCH OF THE REGION. THIS MAY LIMIT

TORNADO POTENTIAL SOMEWHAT WITH STORMS OCCURRING E OF THE DRYLINE.

THE ONE EXCEPTION MAY BE ALONG AND N OF A LBB-LTS LINE...WHERE CLOUD

COVER LASTED LONGER...LIMITING STRONG BOUNDARY LAYER MIXING THROUGH

MUCH OF THE AFTERNOON. OTHERWISE...LARGE HAIL AND DAMAGING WINDS CAN

BE EXPECTED AS STORMS MATURE DURING THE LATE AFTERNOON AND

EVENING...WITH UPSCALE GROWTH POSSIBLE BY 03Z AS LLJ STRENGTHENS TO

40 KT.

..GARNER.. 05/12/2009

[Roger J Smith]

NSR, I think there is some chance of severe cells firing across the western half of the TX panhandle. I am pumped about the explosive potential further north because I see the jet heading rapidly southeast and winds are very strong through the passes in Colorado at this point, with the 00z prog chart showing a lee low pressure feature in eastern CO ... with the 582 dm thickness contour progged to intrude into w KS at that point. Also strongest heating is currently around sw KS (relative to normal). And there are slowly developing cells that have supercell shape if not intensity south of Limon CO.

The TX panhandle option may prove to be successful ... I hope so because I gather that's where the team is located. Further north looks more volatile to me, and if I were chasing I would take the risk on driving north to be in place to intercept what may become tornadic supercells around 23-01z or in about three hours from now. The only thing that is really different from the Greensburg tornado situation is that today's upper trough is dropping into place from further northwest, but what I'm saying is that by 03z it will be almost identical ... whether it fires up similar cells, we'll have to wait and see. Of course, we should hope that these would miss towns in KS and travel over open country when they do form.

But it's fascinating stuff, watching these powerful forces of nature and realizing how complex it all is, on occasion -- although there are some days that are perhaps less subtle, like tomorrow in IL-IN is looking, the question there is not whether, but how many and how severe. I think tonight will get quite intense, and then tomorrow will refire and with the denser population grid further east, it will be perhaps the most significant tornado day of 2009 so far.

[nsrobins]

Thanks for the response, Roger, much appreciated by a student of the art such as me.

I see the mini-cluster of elevated stuff SW of Plainview is getting more organised.

[ian cameron]

Been sitting just 30 Miles east of the dryline for about 2 hours and now we have something organising which you should be able to see on the stream

Paul S

Edited May 12, 2009 by ian cameron

[Nick F]

Great streaming view of the cells popping up to the west of team. Fantastic to see what is actually going on on the ground rather than relying on radar and satellite. Some dry line magic going on ...

Ian, how's the stomach?

[MAF]

thanks for the updates guys. not got streaming here so good to read whats going on. Ian have you eaten today yet?

guys its been pretty wet out there lately, is the ground still waterlogged off the main roads?

[Paul]

Just a quick note - have posted an early heads up as we've started to take bookings for 2010 with the opportunity to pay a low deposit and make monthly payments for early bookers. This will be publicised across the site from tomorrow and places are limited....

http://www.netweather.tv/forum/index.php?showtopic=54975

[ian cameron]

thanks for the updates guys. not got streaming here so good to read whats going on. Ian have you eaten today yet? :lol:

guys its been pretty wet out there lately, is the ground still waterlogged off the main roads?

Hiya Mick yea had lunch today felt like a stranded whale for a while last night but good now.

The sun is out and 30C so hot hot hot the place is looking dryer than it did a week ago so maybe dirt roads will be an option once more, at the mo we have to big cells firing at the same time one heading straight towards us and one more to our south west

[MAF]

Hiya Mick yea had lunch today felt like a stranded whale for a while last night but good now. The sun is out and 30C so hot hot hot the place is looking dryer than it did a week ago so maybe dirt roads will be an option once more, at the mo we have to big cells firing at the same time one heading straight towards us and one more to our south west

sounds like you may get some good photo chances then Ian.

:lol: @ stranded whale

[Nick F]

Looks to me the storms just west of the team are struggling a little to get organised, not supercellular yet. I guess they are struggling due to light winds aloft not seperating downdrafts from updrafts. Think after 00z - when the LLJ cranks up - shear may become more favourable for supercells to develop.

[Roger J Smith]

Research suggesting an energy peak of an embedded cyclonic wave feature with radius of about 200-300 miles will occur around 0345z (10:45 pm CDT) over west-central KS, suggesting that cells now developing in nw TX and se CO will phase and move northeast, merging with cells moving ESE yet to develop along the cold front spilling out of the northern CO mountains around 00z.

Volatile situation, major severe cells may develop anywhere from south of Amarillo to north of Liberal KS around 7 pm CDT and become tornadic by 8 pm possibly in a line from about Scott City KS to near Borger TX, peaking from near Jetmore KS through Dodge City towards McLean east of Amarillo after 0230z (which is around sunset in this vicinity).

This energy peak has a period of 2.6 days and is most effective when it happens in the late afternoon or evening hours as with this situation.

[Mammatus]

Loving the view on the live streaming

EDIT: There on the move again.

Seasons

Edited May 12, 2009 by Seasons

[Tommyboy2007]

Loving the view on the live streaming

EDIT: There on the move again.

Seasons

Yeah, but cam is facing NE whilst fun is straight ahead and slightly west. Am I being picky again ?

Yeah, but cam is facing NE whilst fun is straight ahead and slightly west. Am I being picky again ?

Wow ! that looks nice :lol:

[Nick F]

Looks like Gustanado central beneath the belly of the storms as they head closer, lot of dirt being kicked up off the dry fields!

[Tommyboy2007]

What is that on the ground ? looks like a dust storm.

[Mammatus]

Awesome!!! Whats going on here :lol:

[Nick F]

What is that on the ground ? looks like a dust storm.

Quite common to see big clouds of dust getting kicked up on the Plains by the downdrafts/outflow of storms. Think the worst occurence I experienced of this was in Ern Colorado last year where all we could see was a haze of dust around us sweeping across the road reducing vis. and not being able to make out the storm itself!

[Tommyboy2007]

Thanks for the panning, can't wait to hear from the team as to what that was.

[NL]

Thanks for the panning, can't wait to hear from the team as to what that was.

Nick has just told you what it is...a Gustnado.. see above for nicks explanation.