Virtual Chase Thread 2011

[nsrobins]

Interesting upgrade in the MO region, related in part to enhanced shear parameters on the latest RUC run probably.

Having a family day today so not much chance to examine the set-up but I'll have a look this evening - might be a decent chase.

Edit: Decent MLSP and insane bullesye of EHI and SRH CE MO 21Z - I wouldn't want to be chasing low-based tornadic supercels there though - hills, forests, lakes - yuk! Bet your life someone will though.

Edited April 22, 2011 by nsrobins

[Paul Sherman]

If you had to draw a bubble over the most atrocious Chase Terrain that is exactly where you would put it :lol: :lol:

Have not got a clue where we would go tbh, Oklahoma looks like a crashing Cold Front and linear, Southern Mo is very pretty but those pine forests and log cabins where the Arklatex meets Southern Missouri and windy clifftop roads dont appeal.

Sod it would probably sit it out in Springfield (Mo) on the Interstate and see what crops up and head east with it.

Illinois looks nice but would be battling against darkness before anything got going.

Should be some good streams tonight though to keep us going, and after tonight we have more Live Streaming tomorrow across Oklahoma and then again in the same areas for Sunday, before another possible back to back Moderate Risk Days for Monday and Tuesday, those Tornado numbers for the 1st-28th are going to be High! :lol:

[Paul Sherman]

Amazing chase prospects on the latest models I have seen. Moderate today with some solid slight risks for Saturday and Sunday across mostly the same areas.

Monday and Tuesday are shaping up to be possible Outbreak Days and if the models stay the same could easily see a SWODY2 Moderate come Easter Sunday, Monday looks like Kansas, Oklahoma and the Ozarks and Tuesday looks like the Lower Mississippi Valley and Gulf Shores.

After Thursday 14th and up to Tuesday 26th it could have been one of the most active 2 Week periods in US History if the projected number of Tornadoes over the next 5 days pans out.

Could easily hit 550+ on the Prelimary Tornado Numbers

[Paul Sherman]

Tornado Watch just Issued for Central and Eastern Oklahoma, very pronounced CU Field along the Stationery CF, Near 4,500jkg of Cape and a few cells popping along the line NE Of OK City.

Numerous Streams to follow tonight with most OUTSIDE Of the Moderate Risk area.

[gpspete]

finished work at 10pm then home watched GRLevel3 to 3am and watched several cams and listened to weather radio

lots of action suprised no one posting on here

Lambert-St Louis International Airport reportedly closed TFN. http://www.dailymail...-concourse.html &

http://www.ksdk.com/...s-St-Louis-area

Passengers were still sat on planes on ground when storm came through trapping them on there aircraft

for some time as a lot of the ground equipment was blown about and damaged

Edited April 23, 2011 by gpspete

[NL]

I was knackered yesterday, (gardening in the fog) and couldn't focus on what was happening but I see there were 24 tornadoes reported yesterday (preliminary) with one going through Lambert International Airport, St Louis, Missouri. Luckily theres no reports of any deaths but 4 people were allegedly taken to hospital and minor injuries dealt with at the airport.

http://edition.cnn.com/2011/US/04/23/missouri.severe.weather/?hpt=T1

[nsrobins]

Current obs and soundings show that inhibition is about to crumble in the CN TX/S OK area as surface temps touch 80 and the 68dps are maximised.

Looking at the EHI 0-3 in the Gainesville area reminds me of May 7 2008 when two or three discrete supercells quickly became tornado warned before the whole system phased and lined-out eastwards at dusk. We chased the tail-end charlie as far as Bonham before cutting loose and crossing the river.

Anyone spaced-out by a double dose of reality-show drivel on TV might think about following developments in the next three hours as something may develop in the Gainsville:Ardmore corridor shortly.

[Paul Sherman]

http://www.spc.noaa.gov/products/watch/ww0187.html

Severe Thunderstorm Watch mainly for Giant Hail - Ouch

[Dorsetbred]

http://www.spc.noaa.gov/products/watch/ww0187.html

Severe Thunderstorm Watch mainly for Giant Hail - Ouch

Paul

Nice onliner in the warning

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550 WTF that's high

[NL]

Storms now firing along the warm/occluded front. Nice looking cell just around Abilene Texas with cloud tops at 52,000ft, (big hailer on the way).

Cell has grown quite considerably in 15 mins.

STORM HAZARDS INCLUDE...

BASEBALL SIZE HAIL

DAMAGING WINDS IN EXCESS OF 60 MPH.

Edited April 23, 2011 by NL

[Arron]

Andy Gabrielson just showed some golf ball sized hail on his live stream

http://www.severestudios.com/cgi-bin/player.pl?username=andy.gabrielson&uid=140

[NL]

SPC issue Meso-discussion concerning severe potential for a Tornado Watch

287

ACUS11 KWNS 232202

SWOMCD

SPC MCD 232202

ARZ000-MOZ000-OKZ000-TXZ000-232300-

MESOSCALE DISCUSSION 0538

NWS STORM PREDICTION CENTER NORMAN OK

0502 PM CDT SAT APR 23 2011

AREAS AFFECTED...NRN AR...SERN OK

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

VALID 232202Z - 232300Z

INCREASING THUNDERSTORM COVERAGE IS ANTICIPATED OVER THE NEXT FEW

HRS ACROSS PORTIONS OF SERN OK AND NRN AR...ALTHOUGH STILL SOMEWHAT

UNCERTAIN DUE TO THE PRESENCE OF AMPLE CLOUD COVER. SHOULD

CONVECTION BECOME ROOTED IN THE BOUNDARY LAYER...A THREAT OF DMGG

WINDS...LARGE HAIL...AND PERHAPS ISOLATED TORNADOES WILL LIKELY

DEVELOP. A TORNADO WATCH WILL LIKELY BE CONSIDERED SOON...AND PARTS

OF SERN OK CURRENTLY INCLUDED WITHIN SVR WW 187 MAY NEED TO BE

UPGRADED TO A TORNADO WATCH.

RECENT SATELLITE TRENDS INDICATE SOME ENHANCEMENT IN CONVECTION

ACROSS ERN OK INTO NWRN AR ACROSS A STALLED FRONT...AIDED BY WEAK

CONVERGENCE ALONG THE FRONT WITH LOW-LEVEL ISENTROPIC ASCENT FOCUSED

N OF THE FRONT. ADDITIONALLY...WEAK DEEP-LAYER ASCENT APPEARS TO BE

OVERSPREADING THE REGION FROM THE SRN PLAINS /PER WATER VAPOR

IMAGERY/. DESPITE PERSISTENT CLOUD COVER ACROSS THE WARM

SECTOR...TEMPERATURES HAVE HEATED INTO THE MID-UPPER 70S. AMPLE

LOW-LEVEL MOISTURE COMBINED WITH THE PRESENCE OF AN EML OVERHEAD HAS

YIELDED MLCAPE VALUES RANGING BETWEEN 1500-2500 J/KG...WITH LITTLE

TO NO CINH. SHORT TERM HI-RES MODEL GUIDANCE INDICATES AN UPSWING IN

SFC-BASED CONVECTION THROUGH 00Z. KINEMATIC FIELDS WILL BE FAVORABLE

FOR SUPERCELLS...GIVEN EFFECTIVE BULK SHEAR 40-50 KTS.

ADDITIONALLY...THE POTENTIAL FOR TORNADOES MAY ALSO

EXIST...PARTICULARLY ALONG THE STALLED FRONT WHERE 0-1 KM SRH

HELICITY IS MAXIMIZED /200-250 M^2 S^-2/.

Cell just North Of Abilene in Jones County is now Tornado warned.

064

WFUS54 KSJT 232212

TORSJT

TXC253-232300-

/O.NEW.KSJT.TO.W.0010.110423T2212Z-110423T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE SAN ANGELO TX

512 PM CDT SAT APR 23 2011

THE NATIONAL WEATHER SERVICE IN SAN ANGELO HAS ISSUED A

* TORNADO WARNING FOR...

EAST CENTRAL JONES COUNTY IN WEST CENTRAL TEXAS...

* UNTIL 600 PM CDT

* AT 507 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A

TORNADO WAS 9 MILES WEST OF NUGENT...OR 8 MILES SOUTHEAST OF

ANSON...MOVING EAST AT 20 MPH.

IN ADDITION TO DANGEROUS TORNADIC WINDS...OTHER HAZARDS INCLUDE...

BASEBALL SIZE HAIL

DAMAGING STRAIGHT LINE WINDS IN EXCESS OF 60 MPH.

POTENTIALLY DEADLY LIGHTNING.

* THE TORNADO IS EXPECTED TO BE NEAR...

NUGENT BY 530 PM CDT...

Edited April 23, 2011 by NL

[craig1uk]

Rotating wall cloud http://weather.wdtinc.com/popout/index.php?M=10164&C=20226&O=10061

[Paul Sherman]

Just dont think there is enough Low Level Shear to get the job done atm.

Also have you seen how many chasers are on this cell, like a frickin zoo

[Paul Sherman]

Amazing chase prospects on the latest models I have seen. Moderate today with some solid slight risks for Saturday and Sunday across mostly the same areas.

Monday and Tuesday are shaping up to be possible Outbreak Days and if the models stay the same could easily see a SWODY2 Moderate come Easter Sunday, Monday looks like Kansas, Oklahoma and the Ozarks and Tuesday looks like the Lower Mississippi Valley and Gulf Shores.

After Thursday 14th and up to Tuesday 26th it could have been one of the most active 2 Week periods in US History if the projected number of Tornadoes over the next 5 days pans out.

Could easily hit 550+ on the Prelimary Tornado Numbers

:lol: :lol: :lol: Alright I admit it I secretly work for the SPC :lol:

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0100 AM CDT SUN APR 24 2011

VALID 251200Z - 261200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF

ARKANSAS AND INTO SOUTHERN MISSOURI...

...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN PORTIONS OF THE SRN

PLAINS EWD/NEWD INTO THE MID AND LOWER MS/MID AND LOWER OH/TN

VALLEYS...

...SYNOPSIS...

A LARGE UPPER TROUGH IS FORECAST TO REMAIN ANCHORED OVER THE CENTRAL

U.S. THIS PERIOD...WHILE AN EMBEDDED SHORT-WAVE TROUGH MOVES ACROSS

THE SRN PLAINS AND EVENTUALLY INTO THE MO VALLEY LATE.

AS THIS STRONG FEATURE PROGRESSES ACROSS THE S CENTRAL

CONUS...SURFACE CYCLOGENESIS IS FORECAST...AS A DEEPENING LOW

TRANSLATES NEWD FROM THE SRN PLAINS ACROSS MO THROUGH THE AFTERNOON

AND EVENING. THIS LOW -- AND AN ACCOMPANYING SURFACE FRONT

PROGRESSING SEWD ACROSS THE SRN PLAINS -- WILL BE A FOCUS FOR

DEVELOPMENT OF POTENTIALLY SIGNIFICANT SEVERE THUNDERSTORMS THIS

PERIOD.

...NERN TX/SERN OK/SERN KS EWD/NEWD INTO THE MID AND LOWER

MS/TN/LOWER AND MID OH VALLEYS...

POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT IS EXPECTED DAY 2

/MONDAY APRIL 25/ FROM ERN PORTIONS OF THE SRN PLAINS INTO THE MID

MS/LOWER OH/TN VALLEY REGION...WITH POTENTIAL FOR STRONG TORNADOES

IN ADDITION TO VERY LARGE HAIL AND DAMAGING WINDS.

WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST TO BE ONGOING AT

THE START OF THE PERIOD...MAINLY ALONG AND N OF THE SURFACE WARM

FRONT FROM PARTS OF OK/KS EWD INTO THE OH VALLEY. AS THE STRONG

SHORT-WAVE TROUGH INVOF THE TX PANHANDLE REGION EARLY SHIFTS EWD

ACROSS TX/OK DURING THE DAY...A WEAK/BROAD SURFACE LOW INITIALLY

FORECAST INVOF N TX/OK IS FORECAST TO UNDERGO

CYCLOGENESIS...SHIFTING NEWD INTO MO THROUGH THE DAY. THIS WILL

ALLOW A SLOW NWD SHIFT OF THE COLD FRONT ACROSS SRN AND CENTRAL

MO/SRN IL...WHILE A COLD FRONT SHARPENS AND SWEEPS EWD ACROSS ERN

OK.

WHILE CLOUD COVER SHOULD ACT TO INHIBIT HEATING -- AND THUS MORE

SUBSTANTIAL DESTABILIZATION -- PARTICULARLY ACROSS NRN PORTIONS OF

THE RISK AREA...MIXED-LAYER CAPE OF 1000 TO 2000 J/KG IS FORECAST TO

DEVELOP AHEAD OF THE FRONT FROM E TX ACROSS THE ARKLATEX INTO AR/SRN

MO AND INTO THE MID MS VALLEY REGION. AS THE TROUGH SHIFTS EWD AND

THE FRONT SHARPENS...EXPECT VIGOROUS STORM DEVELOPMENT TO OCCUR

ACROSS SWRN MO...ERN OK...AND E TX DURING THE AFTERNOON WHICH --

GIVEN STRONG/FAVORABLY VEERING FLOW WITH HEIGHT -- SHOULD QUICKLY

BECOME SUPERCELLULAR. ALONG WITH THREATS FOR VERY LARGE

HAIL...ESPECIALLY ACROSS E TX AND THE ARKLATEX REGION...TORNADOES

ARE ALSO EXPECTED -- A FEW POSSIBLY STRONG/DAMAGING. THESE INTENSE

STORMS SHOULD SHIFT NEWD ACROSS THIS REGION WITH TIME TOWARD THE MID

MS VALLEY...WITH THE LIKELIHOOD FOR UPSCALE GROWTH OVERNIGHT INTO

LINEAR CLUSTERS. ALONG WITH A CONTINUED THREAT FOR A FEW

TORNADOES...MORE WIDESPREAD DAMAGING WIND THREAT COULD EVOLVE AS

STORMS SHIFT ACROSS THE MID MS AND LOWER OH VALLEY REGIONS THROUGH

THE EVENING/OVERNIGHT.

[Dorsetbred]

Could easily hit 550+ on the Prelimary Tornado Numbers

Numbers NOW at 559 provisional, better up your guestimate, Paul

[Nick F]

Anyone else like the new layout of the SPC risk boxes? Have to get used to SLIGHT risk areas being yellow rather than green!

Anyway, looks like an Arkansas chase tomorrow, ideally chasers want to be chasing east of the Arkansas river where it's flatter with less trees, ideally the opportunity of intercepting supercells in that area early on while they are discrete, Stuttgart probably my spot to target.

[Gorky]

Nice rotation on the cell SE if Abilene showing on Andy Gabrielson's cam..

http://www.severestudios.com/livechase

[Dorsetbred]

Still some thunderstorm activity at this time south of Wichita Falls and NW of Fort Worth, heading towards Jacksboro.

Shows up nicely on the radar at http://www.wfaa.com

Edited April 25, 2011 by Dorsetbred

[Paul Sherman]

Scary 3 Days coming up for Tornado Numbers

Back to Back Moderate Risks with 15% Hatched today in Tom's old stomping ground near Pine Bluff (Ar) this could be followed by a Moderate / High risk for Wednesday, dont know about 550+ could be 650+ by the time the 28th rolls around.

Like Nick the only decent chase terrain around there would be to start in Stuttgart as you have about 100 miles of flat rice fields all the way to Memphis and towards NE Arkansas and the Bootheel.

Paul S

[Paul Sherman]

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

As expected they have put in a SWODY3 Moderate which is almost certain to become our 2nd High Risk of the Year by Wednesday, and as is typical of a La Nina Spring much further east once again with the Ohio, Tennessee and Mississippi Valleys the focus.

I would now go with upto 700 Prelimary Reports of Tornadoes by the end of April Which could make it a record breaking April by the time the numbers are rounded down for duplicate reports etc

[NL]

Lets hope May and June follow April in possible record breaking tornado numbers.

Lots of chasers out yesterday, particularly the Abilene Texas storm, heres Andy Gabrielson's video of tornadoes from that cell.

[gpspete]

the weather channels: Dr. Greg Forbes, Tornado Expert tornado risk today http://wwworigin.weather.com/outlook/weather-news/news/articles/torcon-daily-forecast_2011-03-24

[NL]

In addition to the severe weather today the levee on Black River in Butler County Missouri has been seriously compromised and is on the verge of a catastrophic breach, according to the Poplar Bluff Police Dept. Mandatory evacuation of southern Poplar Bluff residents have been implemented and have been asked to get to higher ground.

http://www.kait8.com...tory-evacuation

Edited April 25, 2011 by NL

[Dorsetbred]

Tornado warnings now up between Hope & Arkadelphia in Arkansas

Edited April 25, 2011 by Dorsetbred