Chase 2009 Day 12 Discussion

[Paul Sherman]

Looking like a fairly active day with a duel threat to contend with. SPC Mentioning the possibiliies of Tornadoes.

With one eye on getting the guests back to DFW On Friday Lunchtime we look likely to be playing the Dryline which should extend from the Warm Front Intersection in North East Kansas South Westward through Central Kansas and SW Oklahoma. Cape Values are again Insane at around 5,000jkg and If a Lone Supercell Can break the Cap which according to the NAM Model does happen then we could be in Business. Initially going to Drift North from an Overnight Position in El Reno (Ok) towards the OK/KS Border area North of Enid at this present time but this could all change in the Morning.

...ERN KS/ERN OK INTO MO/AR...

VERY MOIST BOUNDARY LAYER IN CONJUNCTION WITH AFTERNOON HEATING WILL

LEAD TO A VERY UNSTABLE AIRMASS ACROSS THE S CENTRAL CONUS...THOUGH

CAPPING/WEAK LARGE-SCALE SUBSIDENCE WILL ACT TO SUPPRESS DEEP

CONVECTIVE DEVELOPMENT -- PARTICULARLY S OF THE RED RIVER AND WWD

INTO THE HIGH PLAINS.

AS A SUBTLE SHORT-WAVE TROUGH EMBEDDED IN WSWLY FLOW ALOFT

APPROACHES THE HIGH PLAINS DURING THE AFTERNOON...WEAK CYCLOGENESIS

IS FORECAST OVER THE SRN HIGH PLAINS ALONG WITH THE DEVELOPMENT OF A

W-E BAROCLINIC ZONE EXTENDING EWD/ENEWD ACROSS THE OK/KS/MO

VICINITY. WITH CAPPING GREATLY LIMITING ANY STORM DEVELOPMENT S OF

THIS DEVELOPING BOUNDARY...WEAK WARM ADVECTION/ISENTROPIC ASCENT

SHOULD FUEL AFTERNOON STORM DEVELOPMENT ACROSS PARTS OF ERN OK/SERN

KS...AND EWD INTO SRN MO/NRN AR. CONVECTIVE COVERAGE SHOULD

INCREASE THROUGH THE EVENING ACROSS KS/NRN OK AND THEN SPREAD EWD

OVERNIGHT...AS A LOW-LEVEL JET INTENSIFIES OVER THE SRN PLAINS.

WHILE ANY ISOLATED STORM WHICH COULD DEVELOP NEAR/S OF THE RED RIVER

WOULD BECOME QUICKLY SEVERE GIVEN THE DEGREE OF INSTABILITY AND

AMPLE/VEERING FLOW WITH HEIGHT...GREATER SEVERE POTENTIAL IS

FORECAST FROM CENTRAL/NERN OK AND SERN KS INTO SWRN MO/NWRN AR.

HERE...FAVORABLE COMBINATION OF SHEAR AND INSTABILITY SUGGESTS THE

THREAT FOR LARGE HAIL...ALONG WITH LOCALLY-DAMAGING WINDS AND

POSSIBLY A TORNADO OR TWO. OVERNIGHT...THE MAIN SEVERE THREAT

SHOULD TRANSITION TOWARD HAIL...AS MORE ELEVATED CONVECTION

REDEVELOPS FARTHER N/W DUE TO INCREASING ISENTROPIC ASCENT ABOVE A

SLOWLY STABILIZING BOUNDARY LAYER.

Friday then looks Interesting for Chase Team 2 and at the Moment it looks like when the last flight arrives and we get going at around 5pm we will be in Full Chase Mode and Move towards Western North Texas around the Witchita Falls Area!!

Hope you guys are ready to hit the ground running.

Paul Sherman

[Gorky]

Good luck with todays chases guys, I'm heading down to Heathrow shortly where I am staying overnight, and may not get online until I am over there on Friday. I expect to check into my hotel in Decatur around 5pm on Friday and am then heading either North or North East into OK to try and get some action. I will likely be heading back down to Decatur at the end of the night, very tired...

[nsrobins]

I'm liking the Red River area from 23Z for say a 35% chance of a cap busting big storm, but higher chances of somewhat less severe action exist with the northern target of SE KS. Mind you, my forecasts relying on a breaking cap have been somewhat dodgy lately.

[Paul]

Team are about to hit the road on the final chase day of tour 1, Paul's briefing (helped by Stu and Tom) is here:

http://www.netweather.tv/index.cgi?action=...ase-video;sess=

The live stream is active and can be viewed here:

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

[nsrobins]

I'm going off the Red River idea now - the cap is just too strong down there. Instead I'm homing in on the Emporia/Burlington area in CE KS for an early evening cap break.

[Roger J Smith]

Expect a slow development cycle today, but explosive development after 00z -- would target Gage OK to Liberal KS and watch out for somewhat of a backdoor frontal development triggering the outbreak after a long period of cap erosion. There may be marginal severe storms in eastern KS but that would be too far from Dallas and probably not that severe, I think the really severe outbreak will develop over the OK/KS border around 01-02z.

[Nick F]

I quite fancy the I-35 corridor between Blackwell N-central OK and Witchita, KS for some sups to develop later. Although there is somewhat better CAPE with big values further south over Oklahoma shown by models, a rather strong cap is in place across much of Oklahoma, thanks to an Elevated Mixed Layer/warm air aloft - which will probably severely limit storm potential today. The OK/KS border north the cap is much less eveident on the hourly analysis. Team look like they are headed in that general direction.

[ukweathergirl]

what's SLGT on the chart mean?

[Paul]

Slight, it's the risk of tornados/hail/severe storms/strong winds. You can also have moderate and high risk :lol:

[ukweathergirl]

ah ok thanks :lol: knew it would be something simple!!

[Nick F]

Cumulus seems to be bubbling up above the team as they head N on the I-35 in N-central OK.

[Sloopy]

Slight, it's the risk of tornados/hail/severe storms/strong winds. You can also have moderate and high risk :lol:

Thanks from me too, things are starting to make sense gradually.

Looks like an interesting few hours

[stevestorms]

Hi everyone Martin and I left from Gainesville this morning and have been sitting in El dorado Ks which is east of Wichita on the road to IMPORIA and have been here since 1400hrs looks like so far we have picked a good spot dry line setting up just to the west just waiting for the trigger now, still we have been to radio shack done some shopping and eaten a Burger King ! phew this storm chasing is hard work!

[nsrobins]

Looks like he cap breaking up in NE KS - TVN has towers going up near Holton on the 75

[NL]

Latest vis satellite image.

Nothing on radar yet apart from those cells in the NE corner over the

Illinois/Missouri border.

[Sno' problem]

And they're off! (The NW team that is)

[ian cameron]

Hiya folks,

well looks like the caps winning today we are going to head south to Ardmore for the night though if anything fires on our way down we will be on it, we have to be that far south as we are changing over teams tomorrow :blush:

Ian

[Roger J Smith]

Watch for development northwest of OKC around 0130-0200z ... dew points are very high in a zone extending north from around Vernon TX to Enid OK (80 F there) ... dry line is weakly depicted at present near the OK-TX border ... pressures are progged to fall rapidly 02-06z across OK ... I think you'll at least get some decent lightning shots after sunset, but with any luck you may get cells going up rapidly just before sunset to the west of the I-35.

[Pete the Britt]

Hey Ian & gang, just checking in to see what the score is for today's chase, really feel for you guys today/tonight after so much hope with the earlier synopsis but i guess that's stormchasing all over.

Have a safe journey back south

Pete

[ian cameron]

Hiya Pete

change of plan we are now staying in Perry tonight as there is a possabilty of supercells firing over our head tonight with baseball size hail predicted so should be a good send of for the team just hope the cars servive the night lol well we are going to get some pizza now the storms should kick off around midnight could be a bumpy ride.

Ian

[stevestorms]

I cant hear the fat lady singing yet!!! we are booked in to the Super8 in Eldorado and I am optimistic of getting something tonight as the warm air aloft weakens , so fingers crossed we are owed somet after cooking all day in 90 degree heat

[Paul Sherman]

We are also Booked into a Super 8 in Perry (Ok) and swapped our Super8 in Ardmore so we can get the Possible Bow Echo and Embedded Supercells to go over for the last night of Chase Tour 1. A Nice 5 Hour drive back to DFW Tomorrow Morning.

It should kick off at 6am Uk Time so watch that Radar.

Good luck in El Dorado Steve and Martin

Paul S

[stevestorms]

Thanks man say bye to the guys and girls and I hope they get a show tonight, we have already got a discrete place lined up for car cover as we dont want to loose the windows :-)

[Paul Sherman]

Hehehehe - Tour 1 Is going to go out with a Bang!

MESOSCALE DISCUSSION 0752

NWS STORM PREDICTION CENTER NORMAN OK

1053 PM CDT THU MAY 07 2009

AREAS AFFECTED...KS/NORTHERN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 080353Z - 080600Z

SEVERE THREAT IS EXPECTED TO STEADILY DEVELOP/INCREASE OVERNIGHT

ACROSS THE WESTERN/SOUTHERN HALF OF KS AND FAR NORTHERN OK...WITH

POTENTIAL FOR SEVERE HAIL/DAMAGING WINDS...ALONG WITH HEAVY

RAINFALL. A WATCH WILL LIKELY BE ISSUED BY AROUND 0430Z-05Z.

TO THE SOUTH OF A WSW-ENE ORIENTED SURFACE BOUNDARY ACROSS KS...00Z

OBSERVED RAOBS/UPPER AIR ANALYSIS REFLECT A RATHER MOIST/POTENTIALLY

UNSTABLE AIRMASS FROM NORTH TX AND OK INTO SOUTHERN/EASTERN KS THIS

EVENING. 23Z/00Z OBSERVED RAOBS FROM LAMONT OK/NORMAN OK SAMPLED

14.4 G/KG AND 17.5 G/KG MEAN MIXING RATIOS RESPECTIVELY...WITH VERY

STEEP MID LEVEL LAPSE RATES /7.5 AND 8.1 C PER KM H7-H5/ AND STRONG

ELEVATED POTENTIAL INSTABILITY /3500 AND 4300 J PER KG MUCAPE/.

WITH INCIPIENT DEVELOPMENT PERHAPS ALREADY OCCURRING ACROSS WESTERN

KS /WEST OF GCK TO HLC/ PER IR SATELLITE IMAGERY...INITIAL DEEP

CONVECTIVE DEVELOPMENT IS ANTICIPATED ACROSS PORTIONS OF WESTERN

INTO SOUTH CENTRAL KS EARLY IN THE OVERNIGHT...AIDED BY THE

EAST-SOUTHEAST TRANSLATION OF IMPLIED LARGE SCALE ASCENT CURRENTLY

ACROSS EASTERN CO/NORTHWEST KS. SIMILAR TO A TREND ALREADY NOTED IN

REGIONAL PROFILER DATA AND 00Z ANALYSIS OF A WESTERN BRANCH LOW

LEVEL JET ACROSS WESTERN OK/SOUTHWEST KS...A STRENGTHENING SOUTHERLY

LLJ /50-65 KT/ OVERNIGHT WILL SUPPORT A CONSIDERABLE ISENTROPIC

LIFT/ELEVATED MOISTURE TRANSPORT REGIME NORTHWARD INTO SOUTHERN KS.

45-50 KT OF MID LEVEL FLOW...AMPLE VEERING THROUGH THE CLOUD BEARING

LAYER...AND VERY STEEP MID LEVEL LAPSE RATES WILL BE RATHER

FAVORABLE FOR A SEVERE HAIL RISK WITH MAINLY ELEVATED SUPERCELLS.

WITH TIME...IT SEEMS PROBABLE THAT STORMS WOULD LIKELY GRADUALLY

CONSOLIDATE AND GROW UPSCALE THROUGH THE OVERNIGHT...WITH POTENTIAL

FOR DAMAGING WINDS/TORRENTIAL RAINFALL INCREASING THROUGH THE EARLY

MORNING HOURS ACROSS SOUTHERN KS/FAR NORTHERN OK...AND EVENTUALLY

INTO ADJACENT SOUTHWEST MO/NORTHWEST AR.

[Tom Lynch]

Thanks man say bye to the guys and girls and I hope they get a show tonight, we have already got a discrete place lined up for car cover as we dont want to loose the windows :-)

You seem to be in with a chance tonight too. May need to think about those windows as we have an early start to get to Dallas.

Tom