Virtual storm chase

[Paul Sherman]

I think what should be noted is the potential for Tuesday 24th April (Exactly 1 week before we leave ) could be an upgrade to High for this day, and if the NAM Is to be believed then could be the most destructive day since May 3rd 1999

Paul S

[kold weather]

Its a decent set-up for sure, a lot of instablity progged, generally somewhere between 3-4000kjs of cape from the models I've looked. not only that but you' ve got a fairly decent jet streakpushing up from the Sw as well which should induce some nasty amounts of shear so supercells looks very very likely. There also should be some deent CIN present in the morning whi9ch should hopefully limit the chance sof any pre-afternoon cells deciding to kick off, hopefully though saying all that the cap dioesn't prove stronger then progged but right now it looks just the right strength for some cracking supercells!

Could be obviously dangerous though, given the amount of shear that will likely be present its not that suprising if something big does kick off!

[pottyprof]

http://www.newschannel10.com/Global/catego...p;nav=menu429_1

Some cracking chase footage by the station team of yesterdays storms.

[Gorky]

Yes, next Tuesday does look like it has the potential to be very serious. The placement of the moderate risk area is pretty bad for a number of large population areas. Let's hope the system slows down or speeds up displacing the worst of the weather East/West of OKC etc. Things look to quieten down significantly after that - let's hope that's not for too long.

[NL]

Some cracking chase footage by the station team of yesterdays storms.

[Nick F]

Day for more Nern sates of the Mid-West this evening under a SLGT risk area, tornado watches out for E Nebraska, W Iowa and NW Missouri:

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

Low centred over this area, with cold front and following trough rotating in from the SW:

Strong deep layer shear from jet aloft suggests supercells and strong 0-1km SR helicity aswell at the surface in the low's circulation suggests likelyhood of tornadoes:

[Paul Sherman]

There could possibly be somewhere between 50 & 100 Tornadoes over the 23rd & 24th Moderate Risks This clearing the east coasts at the end of this coming week, then a settled period expected, with our first 3 days likely to be under a Ridge, so some sightseeing or possibly some Upslope Storms may be possible, things look a bit healthier by Friday 4th May as the Ridge is certainly no "Death Ridge" this also backed up by Tony Gilbert over on Ukww, lots can change in the meantime.

Paul Sherman

[Nick F]

Hi Paul, damn shame we weren't a week earlier, but c'est la vie as they say, does look quiet early next week, but as Tony was saying, shouldn't be long 'till the next upper trough moves in from the West

[Paul Sherman]

So tempted to go tomorrow Nick !! but Louise has threatened me with Divorce

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1231 PM CDT SUN APR 22 2007

VALID 231200Z - 241200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF WRN OK AND NORTH

TX...

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

PLAINS...CNTRL PLAINS...HIGH PLAINS AND WRN OZARKS...

...SIGNIFICANT SEVERE THUNDERSTORM EVENT EXPECTED ACROSS PARTS OF

THE SRN PLAINS MONDAY AFTERNOON AND EVENING...

...SRN PLAINS...

LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH ALONG THE

WEST COAST TODAY AND THIS FEATURE WILL MOVE EWD INTO THE FOUR

CORNERS REGION MONDAY. A WELL-DEFINED 80 TO 90 KT MID-LEVEL JET

ROUNDING THE BASE OF THE TROUGH AND A SRN STREAM JET OVER NRN MEXICO

AND CNTRL TX WILL BEGIN TO AFFECT THE REGION MONDAY AFTERNOON. THESE

FEATURES ALONG WITH SUBTLE LEAD SHORTWAVE TROUGH ACTIVITY WILL

PROVIDE STRONG LIFT SUPPORTING SCATTERED THUNDERSTORM CLUSTERS

ACROSS THE REGION MONDAY AFTERNOON. AS VERTICAL SHEAR INCREASES DUE

TO THE INFLUENCE OF THIS COMPLEX JET STRUCTURE ASSOCIATED WITH THE

UPPER-LEVEL TROUGH...A VERY HIGH POTENTIAL FOR SEVERE THUNDERSTORMS

WILL EXIST ACROSS THE REGION MONDAY AFTERNOON AND EVENING.

FORECAST SOUNDINGS FOR MONDAY AFTERNOON ACROSS THE REGION SHOW 0-6

KM SHEAR VALUES IN THE 40 TO 50 KT RANGE INCREASING INTO THE 50 TO

60 KT RANGE DURING THE EVENING. CONSIDERING MODERATE INSTABILITY

SHOULD BE PRESENT FROM THE RIO GRANDE VALLEY EXTENDING NWD INTO

NORTH TX AND OK...THE SHEAR WILL BE FAVORABLE FOR SUPERCELLS.

LOW-LEVEL SHEAR PROFILES ON FORECAST SOUNDINGS ALSO APPEAR FAVORABLE

FOR TORNADOES AND A SIGNIFICANT TORNADO THREAT MAY DEVELOP AS

SUPERCELLS MATURE LATE MONDAY AFTERNOON. A CLUSTER OF TORNADOES

APPEARS LIKELY ACROSS PARTS OF THE MODERATE RISK AREA WHERE STRONG

LOW-LEVEL SHEAR PROFILES WILL EXIST. IN ADDITION...A PLUME OF VERY

STEEP LAPSE RATES IS FORECAST TO MOVE EWD INTO NORTH TX AND SRN OK

BY LATE AFTERNOON ASSOCIATED WITH THE EXIT REGION OF THE MID-LEVEL

JET. THIS WILL PROVIDE SUPPORT FOR NUMEROUS LARGE HAIL EVENTS WITH

SUPERCELLS DURING THE LATE AFTERNOON AND EVENING. THE ATMOSPHERE

SHOULD ALSO BE SUPPORTIVE OF VERY LARGE HAIL WITH THE MOST INTENSE

STORMS. ISOLATED WIND DAMAGE WILL ALSO BE LIKELY WITH SUPERCELLS AND

BOW ECHOES ESPECIALLY AS MCS ORGANIZATION TAKES PLACE IN THE

EVENING.

...CNTRL PLAINS/HIGH PLAINS...

WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH OVER THE WEST COAST

AND THIS FEATURE WILL MOVE EWD INTO THE FOUR CORNERS REGION MONDAY.

EAST OF THE UPPER-TROUGH...A DIFFLUENT UPPER-LEVEL PATTERN WILL

EXIST ACROSS THE HIGH PLAINS AND CNTRL PLAINS. ALTHOUGH THE JET

ENERGY ASSOCIATED WITH THE TROUGH WILL REMAIN SOUTH OF THE

REGION...THE DIFFLUENCE WILL BE FAVORABLE FOR SCATTERED THUNDERSTORM

DEVELOPMENT ALONG AN INSTABILITY AXIS LOCATED FROM SRN KS EXTENDING

NWWD INTO ERN CO. THUNDERSTORMS SHOULD INITIATE ALONG THE

INSTABILITY AXIS AND MOVE EWD INTO THE CNTRL PLAINS LATE MONDAY

AFTERNOON INTO THE EVENING.

FORECAST SOUNDINGS ACROSS THE REGION LATE MONDAY AFTERNOON SHOW 0-6

KM SHEAR VALUES IN THE 40 TO 50 KT RANGE LARGELY DUE TO STRONG

DIRECTIONAL TURNING BELOW 500 MB. THIS SHOULD BE SUFFICIENT FOR

SUPERCELLS ESPECIALLY IF POCKETS OF MODERATE INSTABILITY DEVELOP

ALONG THE MOIST AXIS MONDAY AFTERNOON. STEEP LAPSE RATES...STRONG

VERTICAL SHEAR AND COLD MID-LEVEL TEMPS SHOULD BE FAVORABLE FOR

LARGE HAIL. IN ADDITION...SFC DEWPOINTS ALONG THE MOIST AXIS ARE

FORECAST TO BE DRIER THAN AREAS FURTHER SOUTH WITH MAINLY 50S F

ACROSS KS AND ERN CO. THIS SHOULD BE CONDUCIVE FOR WIND DAMAGE WITH

SUPERCELLS AND BOW ECHOES ESPECIALLY ASSOCIATED WITH SHORT LINE

SEGMENTS. ALTHOUGH...LCL HEIGHTS WILL BE HIGHER THAN AREAS FURTHER

SOUTH...A TORNADO THREAT MAY ALSO EXIST WITH SUPERCELLS DUE TO THE

BACKED SFC WINDS AND ESPECIALLY WITH SUPERCELLS THAT CROSS ANY

PRE-EXISTING BOUNDARIES.

...MS VALLEY/OH AND TN VALLEYS...

AT THE SFC...A SLOW MOVING COLD FRONT SHOULD BE PRESENT FROM OZARK

REGION EXTENDING ENEWD INTO THE OH VALLEY. ALTHOUGH A FLAT

UPPER-LEVEL RIDGE IS FORECAST ACROSS THE REGION MONDAY...LOW-LEVEL

CONVERGENCE SHOULD BE SUPPORTIVE OF SCATTERED THUNDERSTORM

DEVELOPMENT ACROSS THE REGION MONDAY AFTERNOON AND EVENING. ALTHOUGH

THE SHEAR ENVIRONMENT IS NOT FORECAST TO BE THAT STRONG...ENOUGH

INSTABILITY MAY DEVELOP ALONG AND AHEAD OF THE FRONTAL BOUNDARY FOR

A MARGINAL SEVERE THREAT. HAIL AND STRONG GUSTY WINDS MAY ACCOMPANY

THE STRONGER THUNDERSTORMS ESPECIALLY NEAR PEAK HEATING.

FURTHER SOUTH THE SRN OZARKS AND WRN PART OF THE TN VALLEY...MODEL

FORECASTS DEVELOP INSTABILITY AND SCATTERED THUNDERSTORMS. IF THIS

OCCURS...VERTICAL SHEAR PROFILES SHOULD BE SUPPORTIVE OF MARGINALLY

SEVERE THUNDERSTORMS FROM THE LATE AFTERNOON TO EARLY EVENING.

Then Round 2 and also in the same Populated Areas

DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0226 AM CDT SUN APR 22 2007

VALID 241200Z - 251200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER CNTRL PARTS OF KS/OK SWD

INTO NWRN AND N-CNTRL TX...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLAINS AND LOWER

MO VALLEY SWD INTO PARTS OF WRN/CNTRL TX...

...SYNOPSIS...

LATEST SHORT AND MEDIUM RANGE MODEL GUIDANCE REMAIN CONSISTENT IN

THE EWD PROGRESSION OF MID AND UPPER-LEVEL LOW FROM THE CNTRL/SRN

ROCKIES INTO THE ADJACENT PLAINS THROUGH THE DAY THREE PERIOD. IN

THE LOW-LEVELS...SOME SMALL DIFFERENCES EXIST WITH REGARD TO THE

TRACK OF THE ATTENDANT SURFACE LOW FROM SWRN KS OR THE OK/NRN TX

PNHDLS TO CNTRL/SERN KS BY WEDNESDAY MORNING. ASSOCIATED WARM FRONT

WILL LIFT NWD THROUGH THE LOWER MO AND MID MS RIVER VALLEYS WHILE

DRYLINE SHIFTS EWD FROM THE ERN OK/TX PNHDLS INTO CNTRL OK SWD TO

CNTRL TX BY 25/12Z.

...SEVERE WEATHER OUTBREAK POSSIBLE TUESDAY AND TUESDAY NIGHT...

...CNTRL/SRN PLAINS...

INGREDIENTS APPEAR TO BE COMING TOGETHER FOR A FAIRLY CLASSIC SEVERE

WEATHER EPISODE OVER THE CNTRL AND SRN PLAINS AS 100-120 KT 250

MB/50-70 KT 500 MB JET STREAKS AND A CONCENTRATED ZONE OF HEIGHT

FALLS OVERSPREAD SYSTEM/S WARM SECTOR. A MOIST BOUNDARY LAYER AIR

MASS SHOULD BE IN PLACE /DEWPOINTS IN THE LOWER TO MID 60S/ BENEATH

STEEP MID-LEVEL LAPSE RATES CONTRIBUTING TO A MODERATELY UNSTABLE

AFTERNOON AIR MASS.

TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY BY AFTERNOON FROM

VICINITY OF SURFACE LOW OVER SWRN KS SWD ALONG DRYLINE INTO WRN OK

AND NWRN TX WITH STORMS MOVING/DEVELOPING EWD/NEWD THROUGH CNTRL AND

ERN PORTIONS OF KS/OK AND N TX MONDAY AFTERNOON AND NIGHT. WHILE

UNCERTAINTIES EXIST WITH RESPECT TO TIMING/LOCATION OF CONVECTIVE

INITIATION AND EVENTUAL CONVECTIVE MODE...THE COMBINATION OF STRONG

VERTICAL SHEAR AND MODERATE INSTABILITY OVER A LARGE AREA INDICATE A

HIGH POTENTIAL FOR NUMEROUS SUPERCELLS CAPABLE OF TORNADOES AND

LARGE HAIL.

THE SEVERE THREAT IS EXPECTED TO SPREAD AS FAR NE AS THE LOWER MO

AND MID MS VALLEYS WITHIN LOW-LEVEL WAA REGIME ALONG AND N OF WARM

FRONT...AND AS FAR SW AS SWRN TX ALONG DRYLINE.

[pottyprof]

Bit of a shame that that lot is coming through too early but that's how it goes..

I'm sure chasing sunsets could be good to do on a quiet day? Must be some nice scenery for something spectacular? Followed by a nice steak??

[Paul Sherman]

Thats the thing Pots, From DFW If there are Blue skies for 3 days we can go to the elevated Parts of Colorado or Caprock Canyon National Park, or head up I35 To Wakita to the Twister Set or to Dorothys House in Kansas, I have numerous things planned if 2 or 3 days present themselves, but the VERY Good thing is it looks like systems will swing into the Plains during our trip so severe events and Supercells should be possible in the remaining 7 days.

Paul S

[Nick F]

That Disscusion above almost makes you wanna cry doesn't it? Reading on stormtrack that this could be only the 2nd time that SPC could put a HIGH risk area out for the day 2 outlook tomorrow!

Though I have a feeling this could be an epic season with plenty of reloads of troughs from the pacific moving East across the plains, so plenty more chances IMO.

[Paul Sherman]

Nick

I have been banging on for months about how different this year is to 2005 & 2006, and the main reason is the VERY Wet winter in Texas, everything is green and plentiful and every Storm wants to Spin this year, I firmly believe this is down to Moisture, and that the Dryline pattern is 85% better this year.

Paul S

[pottyprof]

Plus with those ideas in mind, you're staying close by the touch paper Paul..

Nick.. I just want to sob anyway.. I think you won't be disappointed. Its just when.... But thats part of the fun I'd recon..

[Paul Sherman]

No Upgrade to High and now feel slightly better about tomorrows Moderate as it now looks likely to be in the vicinity of the Jungles and Swamps of Eastern Oklahoma So would have been quite a task to track a Nado down over there, but today looks pretty spectacular and I am going for an early target of Elk City just west of OK City.

Paul Sherman

[NL]

Yup, still no upgrade, many of the pro stormchasers still think tomorrow

will be a significant event some are calling 2003, some dare i say 99'!!

Anyhoos today's storm chase i'll dip for Carmen Alfalfa county Oklahoma..

[pottyprof]

I'm going for Tribune. You reckon I'm too far west? Looks like a place with decent road networks should I need to readjust.

[Nick F]

Bit of a late punt for me, but I'm going for Garden City South-West Kansas. Looking at the 12z NAM output - this area seems to have the best combination of high CAPE, deep layer shear for supercells and also high SR helicity and sfc wind shear for tornado potential. Also clear skies are prominent here looking at Satellite - while further East cloud is present.

Hourly mesoanalysis shows some decent 0-6km deep layer shear over W Kansas and Colorado, also 0-1km SR helicity and wind shear values look ideal over W Kansas for severe/tornado potential:

[Paul Sherman]

I know this is a No-No but if I was out there I probably would have shifted from Elk City Northwards and westwards towards Dodge City, awaiting the Colorado Hailing Supercells, a bit too much Cloud inhibiting stuff in the Panhandles recently. So South West and Western Kansas look a good bet today, but this would present itself as a big headache if we were there, 2 or 3 Targets, go with gut instinct.

Paul Sherman

Target 1 # Still love the Look of Elk City / Shamrock

Target 2 # Around Dodge City and South West Kansas

Wish we could split in 2 for this one

[Nick F]

Still waiting for the moisture to increase from the South over Kansas though, dew points still only 54-55F over Wern KS while they are 65-68F further South over Wern OK!, South of a warm front seen on the sfc chart and surface obs below:

Surface obs above you can see that drier air West of the dry line over the far West of TX Panhandle.

[pottyprof]

You're going to have a good few days like this where youll be spoilt for choice, with any luck...

Couple of watches issued..

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 165

NWS STORM PREDICTION CENTER NORMAN OK

210 PM MDT MON APR 23 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

EASTERN COLORADO

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 210 PM UNTIL 900

PM MDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH NORTHWEST OF

AKRON COLORADO TO 40 MILES WEST SOUTHWEST OF SPRINGFIELD

COLORADO. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).

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.

DISCUSSION...TSTMS EXPECTED TO DEVELOP OVER THE NEXT HOUR OR SO IN

INCREASINGLY MOIST/UPSLOPE FLOW INVOF DENVER CYCLONE OVER E CNTRL

CO. OTHER STORMS MAY FORM OVER THE FOOTHILLS AND MOVE/DEVELOP EWD.

BACKED LOW LEVEL WINDS AND EXPECTED DISCRETE TO SEMI-DISCRETE NATURE

OF STORMS SUGGEST POTENTIAL FOR TORNADOES IN ADDITION TO HAIL. SOME

OF THE STORMS MAY STRENGTHEN AND CONSOLIDATE INTO A CLUSTER OR TWO

THIS EVENING AS SHEAR/LARGE SCALE ASCENT INCREASE AHEAD OF

EWD-MOVING GRT BASIN UPR LOW.

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

SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

400. MEAN STORM MOTION VECTOR 21030.

[Nick F]

Latest Tornado watch for SW KS, OK PANHANDLE and TX PANHANDLE, joins watch for Ern CO:

Beat me to it Potty!

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 166

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT MON APR 23 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

SOUTHWEST KANSAS

WESTERN OKLAHOMA AND THE OKLAHOMA PANHANDLE

WEST TEXAS AND THE TEXAS PANHANDLE

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

1000 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 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 20 MILES NORTHEAST OF GARDEN

CITY KANSAS TO 15 MILES WEST SOUTHWEST OF CHILDRESS TEXAS. FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU6).

[Paul Sherman]

About time too with the Tornado Watch Box Nick

Both Dodge & Elk / Shamrock in that Watch, would still be favouring the Shamrock Location at present.

Paul S

If you want to listen to the NOAA Weather Radio Coverage and get the warnings first then Fort Collins (Colorado) has 2 rapidly developing Supercells on the go already

http://www.nws.noaa.gov/nwr/streamaudio.html#livestream

[Nick F]

The upslope must be helping those supercells form North of Denver over Ft Collins then, right on the Front Range of the Rockies.

Some cells firing just South of the I-40 East of Amarillo now, and further NE over Wern OK.

[Paul]

Blimey, I drove through there just a few weeks ago!