Chase 2010 - Day 4 Discussion

[Nick F]

Going to be a tough one to target somewhere for today, with no reedeming focii for storm development away from cold front in the warm sector east of the team across Arkansas, Missouri and Iowa. The active part of the cold front currently lies SW to NE from the I-40 west of OK city through eastern Kansas and on up into N-central Iowa where a low has developed.

The team will obviously need to punch east through the cold front into the warm sector to perhaps find an area where some discrete storms may develop from afternoon heating in the warm sector. personally I would initially target central Missouri around Columbia to Jefferson City E of Kansas City on the I-70, here WRF shows good pooling of moisture and highest CAPE values, wind fields look fairly good too with winds backing SSE/SE - which will increase shear/helicity and make any storms that form rotate and perhaps form tornadoes:

Ideally, the best SR Helicity fields, and thus potential for tornadoes, are over eastern Missouri - as the RUC shows for 21z, so if there was time it would be benefical to perhaps head to the eastside of MO, but it is along trek! Trouble is the terrain aint great in Missouri ,or Misery as Paul likes to call it - with lots of trees and hills. So I can see strongly why Iowa would be a more attractive option, but I think Missouri has the slight edge for favourable Kinemantics, with better moisture and wind fields.

- RUC 0-1km/0-3km SR Helicity for 21z (3pm CDT)

Could always play with the cold front too! Though finding a tornado on a linear frontal MCS is more difficult.

[nsrobins]

Good summary, Nick. I would be looking at Wildwood, MO for highest shear values and gambling on the CF stalling a bit in the next few runs.

[Paul Sherman]

Thanks for starting the Thread Nick.

Although this is a 10% Tornado Risk it really is going to be a needle in a Haystack or 5 Numbers and the Bonus Ball to find the best Storms today, current Plan is to drop South from Concordia and then east along the I-70 Corridoor and as you say get the other side of the CF. Looks like another massive Driving day after yesterday's gruelling 600 mile chase

Hopefully the 13z SPC Makes it a bit clearer

Paul S

[Gorky]

I'd love to be able to offer some opinions on today, but a late night watching the storms, late to work, and everyone seems to be ill or on holiday so I'm to my eyeballs. Probably won't be around in the evening so I'll just have to wish you good luck with the chase, Central MO is an absolute nightmare so be careful if that's where you end up, but I'm sure you know that! Congrats on the chase yesterday. Looks like everyone had a great time!

[kold weather]

Yeah looks like they are going to have to trek eastwards back into the warm sector, esp given the front is over them right now already, I'm guessing the sky resembles very much something you'd see in the UK most dull days right now!

I agree with Nick, the best chances of a tornado today would be the eastern side of Missouri if you were to look at just the set-up, though from the sounds of things its poor chasing terrain. It all just depends on how far you really want to travel and whether your prepared to trade off possible poor terrain for a slightly better upper conditions or vice versa.

Yep Paul its a big region of pretty similar values in terms of instablity, the Helicity does improve somewhat towards late afternoon in E.MO as Nick flagged up, whether its enough to justify what would be another very very long drive is upto you guys really!

ps, by the way the live stream is great, you really do feel your there yourself and you can watch the radar/chaser position to get a real good idea of whats going on, it'd be even more amazing to see a tornado on it!

Edited April 30, 2010 by kold weather

[Nick F]

Although this is a 10% Tornado Risk it really is going to be a needle in a Haystack or 5 Numbers and the Bonus Ball to find the best Storms today, current Plan is to drop South from Concordia and then east along the I-70 Corridoor and as you say get the other side of the CF. Looks like another massive Driving day after yesterday's gruelling 600 mile chase

Hopefully the 13z SPC Makes it a bit clearer

Paul S

One thing you could look out for is an outflow boundary moving east from the cold front across MO, can often see these on the doppler reflectivity, and these boundaries may provide the focus for storm development.

I won't be around from this evening until Monday evening, so all the best with your chasing this weekend - and hope yet find some tornadoes. I will hopefully do an update early this evening.

[Gorky]

Just had a breif look.. Probably a little out of reach for the team if they've only just setup , but as a virtual target, I'll say Bentonville, AR, near the MO border. This is mainly because it looks like the most populated area around that part of the risk zone so I'm hoping it's flatter and less wooded :ph34r: Still, parameters seemed nice down there at about 19z for some mid afternoon storms.

[Nick F]

12Z RUC seems to indicate that by 00z UTC (18z CDT) the St Louis Metro area looks most favorable for tornadic supercells looking at the CAPE, helicity and ppn charts. Not that you want end up chasing in a metro area and it's a hell of a long way east.

east central Missouri just about do-able.

[NL]

SPC have meso discussion on where they expect the greatest severe weather threat to be.

MESOSCALE DISCUSSION 0419

NWS STORM PREDICTION CENTER NORMAN OK

0918 AM CDT FRI APR 30 2010

AREAS AFFECTED...CNTRL/NRN MO...SERN IA...NWRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 301418Z - 301515Z

AN ELONGATED...BROKEN BAND OF ELEVATED THUNDERSTORMS IS GRADUALLY

SPREADING NEWD WITHIN ANA-FRONTAL REGIME FROM SERN KS...NEWD INTO

NCNTRL IA. STRONG LLJ APPEARS TO BE THE PRIMARY FORCING FOR ONGOING

ACTIVITY AS MOST LIKELY INFLOW LAYER FOR THESE UPDRAFTS IS ROOTED

NEAR 850MB. 12Z SOUNDING FROM SGF IS QUITE CAPPED WHILE DOWNSTREAM

ENVIRONMENT OVER SERN IA EXHIBITS CONSIDERABLE MUCAPE ALONG NERN

PLUME OF MOISTURE SURGE. LATEST THINKING IS HAIL IS THE PRIMARY

CONCERN FOR THE NEXT SEVERAL HOURS. HOWEVER...WITH TIME ANY

BOUNDARY LAYER WARMING WILL ENHANCE THE LIKELIHOOD FOR NEAR-SFC

BASED UPDRAFTS TO STRENGTHEN WITHIN VERY FAVORABLE SHEAR. AS

BOUNDARY LAYER DEEPENS THE THREAT FOR DAMAGING WINDS WILL

INCREASE...ESPECIALLY AHEAD OF BOW-TYPE STRUCTURES. WW MAY BE

REQUIRED.

..DARROW.. 04/30/2010

[kold weather]

As you say Nick some of the higher resolution models are very keen on C/E parts of MO, the WRF produces a beefy area of storms in SE MO, but that maybe just a little too far to travel out of the way really. The models still look decent for C.MO, but I wouldn't want to be any further west then that really looking at the models.

However terrain goes get worse further into MO from what I've heard so I'd probably target a similar area as the NW team probably, given its close to the main zone.

Edited April 30, 2010 by kold weather

[Nick F]

We now have a MODERATE risk across E Missouri and W Illinois

Seems to have upgraded because of the 45% wind damage probability though, could be some nasty conditions later, perhaps a derecho type situation. Still potential for a strong tornado - more particularly the blue hatched area on the tornado probability chart below across Sern/SEern MO and Nern AR.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1131 AM CDT FRI APR 30 2010

VALID 301630Z - 011200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF IL AND MO...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MS

VALLEY...WRN GREAT LAKES...OZARKS AND SRN PLAINS...

...MID TO UPPER MS VALLEY/OZARKS...

AN MCS CURRENTLY OVER NCNTRL MO WILL CONTINUE ENEWD INTO NCNTRL IL

THIS AFTERNOON. A BROAD LOW-LEVEL JET SOUTH OF THE MCS ACROSS SCNTRL

MO AND AR WILL RESULT IN STRONG MOISTURE ADVECTION. EXPECT MODERATE

DESTABILIZATION ACROSS MUCH OF MO AND AR BY LATE THIS AFTERNOON AS

SFC DEWPOINTS INCREASE INTO THE MID 60S F. MODEL FORECASTS ARE IN

GOOD AGREEMENT...INITIATING NUMEROUS SFC-BASED THUNDERSTORMS ALONG

THE WRN EDGE OF A WELL-DEVELOPED LOW-LEVEL JET FROM ECNTRL MO SSWWD

INTO THE ARKLATEX. THE SHEAR ENVIRONMENT ALONG THIS CORRIDOR WITH

0-6 KM SHEAR VALUES AROUND 50 KT SHOULD BE FAVORABLE FOR NUMEROUS

SEVERE STORMS INCLUDING SUPERCELLS AND ORGANIZED BOWING

LINE-SEGMENTS. A SIGNIFICANT SEVERE WEATHER EVENT WILL BE POSSIBLE

ACROSS THE MODERATE RISK AREA THIS AFTERNOON THROUGH TONIGHT.

THE CURRENT THINKING IS THAT THE LINE OF STORMS IN NW MO WILL BECOME

INCREASINGLY ORGANIZED MOVING ENEWD ACROSS NRN MO AND SE IA THIS

AFTERNOON INTO WRN IL EARLY THIS EVENING. A LINEAR MCS IS EXPECTED

WITH THE STORMS MOVING INTO INCREASING LOW-LEVEL FLOW WHERE FORECAST

SOUNDINGS SHOW ABOUT 50 KT AT 850 MB LATE THIS AFTERNOON. THIS ALONG

WITH INCREASING LARGE-SCALE ASCENT DUE TO A UPPER-LEVEL SYSTEM TO

THE NORTHWEST AND STRENGTHENING MID-LEVEL FLOW ASSOCIATED WITH THE

RIGHT ENTRANCE REGION OF A 90 TO 100 KT MID-LEVEL JET WILL LIKELY

PROMOTE STRONG LINEAR DEVELOPMENT FROM WRN IL SWD ACROSS ECNTRL MO

EARLY THIS EVENING WHERE THE WIND DAMAGE THREAT SHOULD BECOME

ENHANCED. TORNADOES AND LARGE HAIL WILL ALSO BE POSSIBLE ESPECIALLY

WITH SUPERCELLS EMBEDDED IN THE LINE. A 45 PERCENT WIND DAMAGE

PROBABILITY HAS BEEN ADDED FROM NRN IL SWWD ACROSS MOST OF ECNTRL

MO.

FURTHER SOUTH ACROSS SERN MO AND AR...MODEL FORECASTS ARE IN GOOD

AGREEMENT...DEVELOPING NUMEROUS THUNDERSTORMS ALONG THE INSTABILITY

AXIS. THE ENVIRONMENT SHOULD BE CHARACTERIZED BY MODERATE

INSTABILITY AND STRONG DEEP LAYER SHEAR ESPECIALLY NORTH OF LITTLE

ROCK WHERE INTENSE SUPERCELL DEVELOPMENT IS POSSIBLE BY EARLY THIS

EVENING. IN NRN AR...LARGE-SCALE ASCENT IS FORECAST TO BE WEAKER

THAN AREAS TO THE NORTH WHICH SHOULD HELP THE SUPERCELLS REMAIN

DISCRETE BUT THE STORMS MAY BE MORE ISOLATED AS WELL. IN

ADDITION...FORECAST SOUNDINGS ACROSS CNTRL AND NRN AR SHOW SFC WINDS

BACKED TO THE SOUTH SOUTHEAST WHICH COMBINED WITH LOW LCL HEIGHTS

COULD BE FAVORABLE FOR AN ISOLATED STRONG TORNADO. THE MORE DOMINANT

SUPERCELL STRUCTURES SHOULD BE CAPABLE OF PRODUCING TORNADOES AND

POSSIBLY VERY LARGE HAIL. THE THREAT FOR VERY LARGE HAIL SHOULD

EXIST ACROSS AR SWWD INTO NE TX WHERE MODERATE TO STRONG INSTABILITY

IS FORECAST.

..BROYLES/STOPPKOTTE.. 04/30/2010

[Paul]

Team are making for what they hope will be the area with the highest tornado risk in southern MO/ nrt Ark

[Roger J Smith]

Tornado risk looks highest in ne MO and w/c IL around Quincy, but if chase has to go south for logistics then West Plains MO to Batesville AR could provide a severe storm around 23z.

[kold weather]

Team are making for what they hope will be the area with the highest tornado risk in southern MO/ nrt Ark

If they can get to C.MO then they should be in a good enough spot....that being said looking at the stream it seems to be one of those messy days that doesn't really crop up with anything too photographic.

The convection also already looking very linear along what I guess is the frontal system, and I'd expect any convection that develops just ahead f the front will very quickly also become linear. so I agree with Nick its the wind threat thats looking the biggest issue today IMO, should be a very interesting day though, as long as they can get far enough east, they should do ok...

Finally I'd just like to say a huge thanks to NW for such a high quality feed, its been great to watch so much of not just the stroms, but the journey as well, really makes you feel like your there chasing as well!

[pottyprof]

I wouldn't trust those wipers.... they're wobbling about all over the place..

[NL]

Tornado watch .

186

WWUS20 KWNS 301850

SEL4

SPC WW 301850

ARZ000-MOZ000-OKZ000-TXZ000-010100-

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 114

NWS STORM PREDICTION CENTER NORMAN OK

145 PM CDT FRI APR 30 2010

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

WESTERN ARKANSAS

SOUTHERN MISSOURI

EASTERN OKLAHOMA

NORTHEASTERN TEXAS

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 145 PM UNTIL 800

PM CDT.

TORNADOES...HAIL TO 2 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 55 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES NORTHEAST OF

SPRINGFIELD MISSOURI TO 15 MILES SOUTHEAST OF PARIS TEXAS. FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU4).

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 111...WW 112...WW 113...

DISCUSSION...STORMS HAVE RECENTLY BEEN DEVELOPING AND INTENSIFYING

IN ERN OK... ALONG AND JUST AHEAD OF A SLOW MOVING COLD FRONT.

MODERATE INSTABILITY AND STRONG DEEP LAYER SHEAR IS VERY FAVORABLE

FOR SUPERCELLS...AS THE STORMS DEVELOP/MOVE EWD THROUGH THE

AFTERNOON HOURS. THE VERY MOIST BOUNDARY LAYER AND 30-40 KT LOW

LEVEL SHEAR WILL BE SUPPORTIVE OF TORNADOES AND LARGE HAIL.

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

SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

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

500. MEAN STORM MOTION VECTOR 23040.

...IMY

[Roger J Smith]

Looks quite good now for sw MO and nw AR, heading south from SGF might be the best play. Could get an intercept near FYV around 21-22z.

[NL]

A large number of huge embedded cells along that CF.

[Cloud]

SPC have increase the tornado probs to 15%. The dewpoints over Arkansas are hitting 70F now.

[user700]

They should be driving through some thunder storms soon

[Gorky]

Pleasantly surprised to see my target area in prime position based of a minute look at the models. Not too hard when half of america seems to be prime position today though... lol. ONly got 2 mins but I'll be home in 40mins to check out the stream and see where the team have made it to :lol:.. very nice probabilities in AR Tor watch. 70/40 is nothing to sneeze at. Nothing spinning up at the moment I see but that may well change as the night goes on...

[NL]

Tornado warned cell to the south of the team in Boone county Arkansas

444

WFUS54 KLZK 302147

TORLZK

ARC009-089-302230-

/O.NEW.KLZK.TO.W.0017.100430T2147Z-100430T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE LITTLE ROCK AR

447 PM CDT FRI APR 30 2010

THE NATIONAL WEATHER SERVICE IN LITTLE ROCK HAS ISSUED A

* TORNADO WARNING FOR...

BOONE COUNTY IN NORTH CENTRAL ARKANSAS

NORTHWESTERN MARION COUNTY IN NORTH CENTRAL ARKANSAS

* UNTIL 530 PM CDT

* AT 446 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 9 MILES

SOUTHWEST OF HARRISON...MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...

HARRISON...

BERGMAN...

LEAD HILL...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...GO INDOORS TO THE LOWEST

FLOOR OF YOUR HOME OR OFFICE. GO TO AN INTERIOR ROOM AWAY FROM

WINDOWS.

[Gorky]

Storm in Boone County tor warned and about to move into MO. The cells behind it, especially the one in Scott county looks ready to go TOR warned. Think that one could become a beauty as it moves into Yell County

[nsrobins]

Well you did better than me - second day in a row that I've been out by 100 miles! The CF passed me hours ago. Interesting to see the most potent looking cells now are feeding off the influx of rich moisture on the AR/MO border. A messy cloudscape that may well hide rotation in the next few hours.

[pottyprof]

According to gps they are in west africa at the mo......