Chase 2009 - Day 1 - Central/nw Texas

[Paul]

The team is now on the way to the USA and will land at around 2.30 local time this pm (8.30 UK). As there is a storm/tornado risk within a couple of hours of the airport they're due to head straight out once they've picked up the chase vehicles, and will hopefully be able to stream live to give you an early taster of the action!

This is the current outlook for today from the SPC:

...SRN PLAINS INTO SRN KS...

A 60-70 SWLY MID LEVEL JET IS EXPECTED TO EXTEND FROM THE WRN

PORTION OF THE SRN PLAINS TO ERN DAKOTAS BY THIS AFTERNOON...ALONG

ERN PERIPHERIES OF RESPECTIVE SHORT WAVE TROUGHS AFFECTING THESE

AREAS TODAY. POTENTIAL EXISTS TODAY FOR SUPERCELLS TO DEVELOP ALONG

THE DRY LINE/SURFACE FRONT INTERSECTION IN SWRN KS/ERN OK PANHANDLE

AND SWD ALONG THE DRY LINE TO PART OF WEST CENTRAL TX. MODERATE

INSTABILITY COMBINED WITH STRONG EFFECTIVE BULK SHEAR /40-50 KT/

SUGGESTS LIKELIHOOD FOR SUPERCELLS. SECOND BRANCH OF SLY LLJ IS

EXPECTED TO DEVELOP/STRENGTHEN ACROSS WRN N TX/WRN OK INTO SRN KS BY

LATE AFTERNOON RESULTING IN INCREASED LOW LEVEL HODOGRAPH

CURVATURE/ATTENDANT TORNADO THREAT.

MODELS DIFFER WITH THE TIMING OF TSTM INITIATION FROM THE TRIPLE

POINT SWD...BUT THERE IS SOME INDICATION THAT ACTIVITY MAY DEVELOP

AS EARLY AS LATE MORNING OR EARLY AFTERNOON. STRONG SURFACE HEATING

SHOULD OCCUR ALONG NRN EXTENT OF DRY LINE...WHILE MORE FILTERED

SUNSHINE MAY OCCUR SWD ACROSS MUCH OF WRN/CENTRAL TX INTO SRN OK DUE

TO MID/HIGH LEVEL CLOUDS SPREADING ACROSS THIS REGION CURRENTLY AND

DURING THE MORNING. STEEP LAPSE RATES ACROSS THIS AREA WITH STRONG

EFFECTIVE BULK SHEAR WILL ALSO BE CONDUCIVE TO LARGE HAIL...SOME

VERY LARGE ACROSS THE MODERATE RISK AREA.

ACTIVITY SHOULD SPREAD EWD ACROSS SRN KS/OK AND N TX AS NRN BAJA

TROUGH MOVES ACROSS THE SRN PLAINS SUNDAY NIGHT. AIR MASS IS SHOULD

REMAIN MODERATELY UNSTABLE INTO SUNDAY EVENING/NIGHT SUPPORTING A

CONTINUED SEVERE WEATHER THREAT AFTER DARK ACROSS THE SRN PLAINS.

[NL]

First Tornado watch for today for SW/central Kansas with a moderate threat

of EF2+ tornadoes and very large hail.

http://www.spc.noaa.gov/products/watch/ww0188.html

Latest visible satellite image shows the sun just starting to bring

some light over Kansas/Oklahoma, great view of those towering

cells affecting SW/central Kansas.

[NL]

Latest update from the SPC have increased the likelyhood of tornadoes to 15%

around Kansas/Oklahoma.

Latest vis satellite image showing quite an abundance of cloud from

yesterdays storms, still there's fairly large breaks that should allow

surface temps to rocket up and aid convection, just hope it doesn't

become a murkfest ..!!

[Nick F]

Looking at the data - looks like NE/Ern TX Panhandle up into OK Panhandle across into rest of Wern OK will be the prime area to be for severe supercells with strong tornadoes to form near the dryline triple point at 00z tonight or 6pm there time. Say Shamrock, TX north to Guymon, OK and across to Clinton and Woodward.

12z WRF for 00z Mon:

RUC has dryline further east by 00z Mon:

That area bit it too far for chase team 1 to get to, but - storms should shift/develop further east as the evening wears on and also storms may break out widely further east - which may put them in reach around Witchita Falls to Vernon area on Hwy 287 - a tough call - but this area falls under SPC's MDT/10% tornado risk area ... so maybe able to catch storms firing further east with a tornado if they are lucky. Certainly may see some large hail

A look at the 12z DFW sounding shows a rather unstable ascent with a very weak cap around 700mb, air is saturated up to around 750mb with sfc dew point around 20C- hence alot of cloud there, dry air above 700mb which is ideal for severe storms, winds backed SE towards surface. Insolation during afternoon there will see those CAPE values rocket I imagine:

Amarillo sounding further WNW also conditionally unstable with a stronger/deeper cap in place between 650 - 900mb, sfc dew points in mid teens:

A rather volatile sittaution developing once we see the cloud break and insolation going especially across NW TX up into OK Panhandle and SW KS where we see the dry line interact.

[Nick F]

Current tornado watch over SW/S-central Kansas likely to be extended further SW according to latest Meso discussion:

MESOSCALE DISCUSSION 0578

NWS STORM PREDICTION CENTER NORMAN OK

1019 AM CDT SUN APR 26 2009

AREAS AFFECTED...CNTRL KS SWD INTO NWRN OK AND ERN TX PNHDL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 261519Z - 261615Z

TORNADO WATCH 188 WILL BE REORIENTED AND EXPANDED SW INTO NW OK AND

ERN TX PNHDL SOON.

APPARENT GRAVITY WAVE HAS INDUCED A LIKELY ELEVATED BAND OF TSTMS

FROM WEST OF KTOP SWWD TO NEAR KICT RECENTLY. ANOTHER BAND OF TSTMS

CONTINUES TO GROW ALONG PRIMARY CDFNT FARTHER TO THE W FROM EAST OF

KRSL TO NW OF KGAG.

TSTMS ARE LIKELY TO BUILD SWWD FROM THE TWO AFOREMENTIONED BANDS

THROUGH THE NEXT SEVERAL HOURS AS THE NM MID-LVL WAVE EJECTS NEWD.

BINOVC ACROSS MUCH OF THE REGION WILL ALLOW AIR MASS TO CONTINUE

WARMING IN THIS REGION...WITH WEAKEST CINH OVER KS EARLY. CAP

SHOULD WEAKEN GRADUALLY FARTHER SW WITH TIME...LEADING TO MORE

SFC-BASED ACTIVITY TO EVOLVE.

VWP/PROFILER DATA SHOW EVIDENCE OF EARLIER WAVE PASSAGE WITH A

VEERING-BACKING PATTERN IN THE LOWEST 6KM. THIS WILL COMPLICATE

STORM MODE EARLY...WITH LINEAR SEGMENTS MOST FAVORED.

HOWEVER...STORM ORGANIZATION INTO SUPERCELLS WITH VERY LARGE HAIL

WILL BECOME MORE LIKELY WITH TIME...ALONG WITH THE THREAT FOR

TORNADOES...ESP LATER THIS AFTN.

..RACY.. 04/26/2009

[NL]

SPC have an outlook upgrade to High risk affecting parts of Kansas and Oklahoma.

MESOSCALE DISCUSSION 0579

NWS STORM PREDICTION CENTER NORMAN OK

1054 AM CDT SUN APR 26 2009

AREAS AFFECTED...KS...OK...NW TX

CONCERNING...OUTLOOK UPGRADE

VALID 261554Z - 261700Z

SEE GRAPHIC FOR MDT-HIGH RISK LINES EXPECTED FOR 1630Z SWODY1

UPDATE.

HIGH RISK UPGRADE WILL INCLUDE SCNTRL KS AND NWRN/NCNTRL-WCNTRL OK

WITH A MDT RISK SPANNING FROM NWRN TX/ERN TX PNHDL ENEWD INTO CNTRL

OK AND CNTRL/ERN KS.

IMPRESSIVE INGREDIENTS COMING TOGETHER LATER THIS AFTN FOR A HIGH

POTENTIAL FOR WAVES OF LONG-LIVED SUPERCELLS WITH STRONG

TORNADOES...DESTRUCTIVE HAIL AND DAMAGING WIND GUSTS.

BRIEF THOUGHTS /DETAILS FORTHCOMING IN SWODY1 UPDATE/...

MORNING ACTIVITY DEVELOPING OUT OF ACCAS FIELD WILL TRANSLATE NWD

INTO CNTRL/ERN KS AND NWRN OK THROUGH EARLY AFTN. PORTIONS OF THIS

ACTIVITY COULD BECOME SFC-BASED AS POCKETS OF HEATING LOCALLY ERODE

CINH. ANOTHER WAVE OF STORMS IS LIKELY TO FORM UPSTREAM ALONG THE

DRYLINE/FRONT IN ERN TX PNHDL/NWRN TX LATER THIS AFTN AND

EVE...TRANSLATING ENE ACROSS THE MDT/HIGH RISK AREAS.

PLENTIFUL BOUNDARY LAYER MOISTURE ALREADY IN PLACE BELOW VERY STEEP

LAPSE RATES WILL CONTRIBUTE TO VERY UNSTABLE CONDITIONS...MLCAPES

3000-4000 J/KG. BULK SHEAR OF 45-50 KTS ORIENTED NORMAL TO THE

INITIATING BOUNDARIES AND PERSISTENT RICH MOISTURE INFLUX WILL FAVOR

LONG-LIVED DISCRETE SUPERCELLS. LOW-LEVEL FLOW WILL REMAIN BACKED

IN A CORRIDOR FROM NWRN TX INTO SCNTRL KS...IMMEDIATELY DOWNSTREAM

FROM AN INTENSIFYING SFC LOW OVER OK PNHDL/SWRN KS...BOOSTING SRH

AND RESULTING IN POTENTIAL FOR STRONG TORNADOES.

..RACY/HART/HALES.. 04/26/2009

[Nick F]

Yep, we thought last night that this was going to go HIGH!

Btw, here's some pics of Chase Team 1 (minus Tammy and Danny who will meet the team later). I am not in these pics (thank god!). At the Sheraton Heathrow Hotel Bar last night.

From left to right: John Hanrahan (Christ I don't Know), Ian Cameron, Pat Carter (dogs32), Tom Lynch and Paul Sherman:

Ian had one too many?

John catching up on the latest info ...

[londonsnow]

our storm chasers were in the bar already last night! good news. no doubt a few other chasers were consumed! outlook looks good.

[dave48]

Nice set up today, can't wait to see the live stream, should be good.

[Nick F]

***** hell, all kicking off early today, just shows how weak the cap is ... PDS (Particularly Dangerous Situation) Tornado Watch issued, moderate risk of EF2+ tornadoes:

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 190

NWS STORM PREDICTION CENTER NORMAN OK

1110 AM CDT SUN APR 26 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

A LARGE PART OF CENTRAL AND NORTHEAST KANSAS

PARTS OF WESTERN AND NORTHERN OKLAHOMA

PARTS OF EASTERN TEXAS PANHANDLE

EFFECTIVE THIS SUNDAY MORNING AND EVENING FROM 1110 AM UNTIL 700

PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 4 INCHES IN DIAMETER...

THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE

POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 50 MILES WEST OF CLINTON

OKLAHOMA TO 65 MILES WEST NORTHWEST OF SAINT JOSEPH MISSOURI.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 188...WW 189...

DISCUSSION...STRONG DEEP LAYER SHEAR COUPLED WITH A VERY UNSTABLE

AIR MASS WILL RESULT IN SUPERCELLS DEVELOPING ALONG AND E OF FRONTAL

ZONE THAT EXTENDS FROM NCENTRAL KS TO TX PANHANDLE. STORMS WILL

INCREASE RAPIDLY IN NUMBER AND INTENSITY THRU THE AFTERNOON AS WARM

SECTOR CONTINUES TO DESTABILIZE WITH TORNADIC SUPERCELLS BECOMING

MOST LIKELY DURING LATER PORTIONS OF WATCH PERIOD. POTENTIAL FOR

LONG LIVED TORNADIC SUPERCELLS ACCOMPANIED BY VERY LARGE HAIL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 24035.

...HALES

Hazard Tornadoes EF2+ Tornadoes

Likelihood High Moderate

Severe Wind 65 kt+ Wind

High Moderate

Severe Hail 2"+ Hail

High High

[multi cellular thunderstorm]

What a day to be landing! Can't wait to see the first stream, pics and reports from the team :huh:

[MAF]

Blimey Guys! just got into work and logged into see the watch #190

hope you are all taking care out there

[MAF]

into watch 191 now

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

PARTS OF WESTERN AND CENTRAL IOWA

PARTS OF NORTHWEST MISSOURI

PARTS OF SOUTHEAST NEBRASKA

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL

800 PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE

MILES EAST AND WEST OF A LINE FROM 15 MILES WEST OF FALLS CITY

NEBRASKA TO 20 MILES NORTHEAST OF FORT DODGE IOWA. FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU1).

courtesy NOAA/SPC

[NL]

Plenty of chasers streaming already i havent seen anything like this before could this

be another 1974..? with multiple episodes of deep convection tornadoes could be spinning

all over the place... and no barons :huh: !!!..

I dont know if any news has reached the team on the flight, if not i'd love to see the look on their faces

when they see the forecast..! Not long now until they land....

[Nick F]

Paul, Pat and Tammy won't be landing until about 8.30ish tonight our time or 2.30pm central US time, then Tom, Ian and John will be on the BA flight an hour later. So by the time the team get checked into the hotel near DFW airport and on the road it'll be about 11pm or 5pm their time. And it's all kicking off already!

Already some cells popping up south of the Hwy 287 between Childress and Witchita Falls (TX), so hopefully they won't have too far to go NWards to chase from DFW area.

^^^Tornado warned cells across Wern OK now south of Clinton, lets hope the storms don't develop near DFW as this may delay their landing.

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE NORMAN OK

1236 PM CDT SUN APR 26 2009

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...

NORTHEASTERN GREER COUNTY IN SOUTHWEST OKLAHOMA...

EXTREME NORTHWESTERN KIOWA COUNTY IN SOUTHWEST OKLAHOMA...

EASTERN BECKHAM COUNTY IN WESTERN OKLAHOMA...

WESTERN WASHITA COUNTY IN WESTERN OKLAHOMA...

* UNTIL 115 PM CDT

* AT 1236 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 7 MILES

SOUTHWEST OF RETROP...MOVING NORTHEAST AT 45 MPH.

* LOCATIONS IN THE WARNING INCLUDE BESSIE...BURNS FLAT...CANUTE...

DILL CITY...ELK CITY AND RETROP.

THIS INCLUDES INTERSTATE 40 BETWEEN MILE MARKERS 38 AND 51.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. LEAVE MOBILE HOMES AND VEHICLES. IF POSSIBLE...MOVE

TO A BASEMENT OR STORM SHELTER. OTHERWISE MOVE TO AN INTERIOR ROOM OR

HALLWAY ON THE LOWEST FLOOR. STAY AWAY FROM WINDOWS AND OUTSIDE

WALLS.

[MAF]

TAKE COVER NOW. LEAVE MOBILE HOMES AND VEHICLES. IF POSSIBLE...MOVE TO A BASEMENT OR STORM SHELTER. OTHERWISE MOVE TO AN INTERIOR ROOM OR HALLWAY ON THE LOWEST FLOOR. STAY AWAY FROM WINDOWS AND OUTSIDE WALLS.

:huh: scary stuff

thanks for the update on the chaser Nick. happy hunting

[Nick F]

To watch out for later - a meso for potential tornado watch for NW TX:

MESOSCALE DISCUSSION 0582

NWS STORM PREDICTION CENTER NORMAN OK

1258 PM CDT SUN APR 26 2009

AREAS AFFECTED...NW-WCNTRL TX AND EXTREME SWRN OK

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 261758Z - 261930Z

MID-LVL TROUGH AXIS CONTINUES TO ADVANCE EWD THROUGH ERN NM WITH

STRONGEST PVA LIKELY TO TRANSLATE INTO NWRN-WCNTRL TX THROUGH EARLY

THIS EVENING. BANDS OF ACCAS HAVE BEEN COMMONPLACE OVER W TX SINCE

EARLY MORNING WITH SFC BASED CBS DEVELOPING OVER THE ERN SIDES OF

THE GLASS MOUNTAINS IN PECOS COUNTY RECENTLY.

EXPECT THAT CLEAN INITIATION ALONG THE DRYLINE /NEARING THE CAPROCK

EARLY THIS AFTN/ WILL BE MUDDLED BY GRADUAL UPSCALE GROWTH/

DEEPENING OF THE ACCAS STREETS INTO TSTMS AS THE DEEP LAYERED UVV

APCHS. INITIAL STORMS WILL PRODUCE LARGE HAIL GIVEN STEEP LAPSE

RATES ATOP THE BOUNDARY LAYER. BUT...AS HEATING CONTINUES AND ACCAS

BOOTSTRAPS INTO THE MOIST BOUNDARY LAYER -AND- ADDITIONAL SFC-BASED

STORMS DVLP ALONG THE DRYLINE...ALL FACETS OF SVR WEATHER ARE LIKELY

AS STORMS EVOLVE INTO SUPERCELLS.

HIGHEST TORNADO POTENTIAL WILL EXIST ACROSS NWRN TX/ERN S PLNS WHERE

STRONGEST SELY LLVL FLOW WILL REMAIN THROUGH EVENING. FARTHER

S...THOUGH TORNADOES WILL BE A THREAT...THE LLVL FLOW/LARGE SCALE

SUPPORT WILL BE COMPARATIVELY WEAKER.

A TORNADO WATCH WILL BE REQUIRED FOR PARTS OF THE REGION LATER THIS

AFTN.

[MAF]

Nick, are the Media ramping the warnings up, or is it a case of "the norm" for this time of year out there?

[Nick F]

Mick, don't think there's any ramping today - this has the potential to be a serious tornado outbreak across parts of Wern OK, NW Texas and Kansas too.

[MAF]

yeah i understand, what i meant by ramping is probably wrong choice of word. perhaps what i should have asked is, are the media on the ball out there with current and constant updates for counties affected?

in comparison to the poor weather updates we have in the country

[saint]

Sorry to butt in.....

Are there any links to live streams?

[Ross B]

Sorry to butt in.....

Are there any links to live streams?

http://severestudios.com/livechase

http://www.tornadovideos.net/full-screen-chaser-video.php

The second link is displayed much better but i dont find the connections are as good.

[MAF]

http://severestudios.com/livechase

http://www.tornadovideos.net/full-screen-chaser-video.php

[Ross B]

yeah i understand, what i meant by ramping is probably wrong choice of word. perhaps what i should have asked is, are the media on the ball out there with current and constant updates for counties affected?

in comparison to the poor weather updates we have in the country

Yep, most news channels have regular updates with storm trackers and live radar/webcams etc.

Even the storm chasers are sometimes on live broadcasts on the phone when tornadoes are on the ground.

[MAF]

thanks Ross. even though we dont have such severe weather, perhaps we could take a leaf out of the US media's book and have better "current conditions" reports here