Virtual storm chase

[Paul Sherman]

Looks likely the next severe weather events in the Plains are likely to be the weekend of the 21st & 22nd April. Possible Dryline set up on the Saturday before the action shifts North-Eastwards on the Sunday into Kansas, Nebraska & Iowa. After that the pattern still looks mobile in the week just before we go, currently our landing day looks like temps of 27c with no storms, but am keeping an eye on the Tuesday 1st May at the moment which could throw up some promise, but this far out the models are likely to chop and change a lot.

Paul Sherman

[Paul Sherman]

Next Saturday and Sunday is still looking increasingly like a MAJOR Event for the Southern and Central Plains. Could be quite a big event if the models hold together. But my attention is now drawn to a Bonus Chase for Tomorrow. SPC Have slapped a Slight Risk for Eastern and North Central & NEastern Texas. These days usually get overlooked and then turn out to be the best chase days of the year, I have a hunch that if a very well defined Dryline can set-up then some Supercells could rampage across parts of Eastern and North-Eastern Texas from Dallas (AGAIN!!) Eastwards, if the dryline set-up does not occur easily then a Messy MCS With embedded Supes are possible but would be VERY Messy. Have a feeling a few Tornadoes could occur tomorrow from 17cdt until 22cdt

Paul Sherman

EDIT : Target location # Sherman (Tx)

[pottyprof]

Did you start drooling as you were typing that Paul?? :unsure:

[Paul Sherman]

Did you start drooling as you were typing that Paul?? :lol:

I have been drooling for the past few weeks Pots !! :lol:

BTW Next weekend is still looking like a Major event, and i'd expect the SPC To whack a MODERATE Risk straight in for either Saturday or Sunday, and it looks like it could even be a High end Moderate if the Models hold together.

Paul S

[Paul Sherman]

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

Kicking off early today, the radar has literally exploded near to Lubbock, so on the radio and listen to the warnings come through loud and clear. Mainly a Hail and Wind threat but would not rule out the odd tornado for today

Paul S

[Paul Sherman]

3 Landspout Tornadoes already today, which is 1 more Tornado than last weeks High Risk !!

Paul S

[pottyprof]

Can see why you like these one day events Paul.

Seem to be fast moving..

[Paul Sherman]

Pots,

If i was chasing this I would let the early stuff go, as that has got Messy MCS Written all over it, what I would be interested in is the stuff crossing from New Mexico into the Texas Panhandle, this would be a tad easier to chase.

Paul S

[pottyprof]

You mean this stuff?

Can't find a live camera at the mo but will keep looking..

[Nick F]

Pots,

If i was chasing this I would let the early stuff go, as that has got Messy MCS Written all over it, what I would be interested in is the stuff crossing from New Mexico into the Texas Panhandle, this would be a tad easier to chase.

Paul S

Not sure I'd place in NW Texas (Panhandle) myself today if I'd want to see best prospects of mesos and tornadoes, as this is where 0-6km deep-layer shear and 0-1km SR helicity is weakest. Though skies are clearer over NW TX area which is a plus. Ideally N Central Texas would be a better bet for severe weather, where the SLGT risk is. Looking at the SPC hourly meso analysis, central TX has strongest deep layer shear (for Supercell formation and mesos) and SR helicity (for tornadoes).

Storms East moving over this area more likely than over NW TX to become supercellular and drop tornadoes:

2000 0-1km SR helicity:

2000 0-6km shear:

[Paul Sherman]

Sorry for the late reply, lost Internet for some reason last night. I know the Slight Risk was centred more towards North Central Texas, and mainly for the reasons that Nick Attached last night, but positioning yourself in front of a Squall Line trying to find the one needle in the haystack isnt always Fun, as it turns out the 1 tornado that formed in this linear junk happened in Tarrant County which is the Metroplex Again!! Usually in May the linear Squall does not usually happen until late in the day after the discrete Supercells have all merged into 1 line, thus we get good Supercell Photo ops and a nice Gust front and lightning show late in the day, the cells over towards the NW Panhandle probably would not have much chance of dropping a tube but the Photo ops would have been much better and sometimes photographing a grat structure is better than getting blown off the road by a 50-80mph gust front.

Regards

Paul Sherman

[BrickFielder]

I am watching Late Saturday quite closely at the minute. Quite a lot of mixed layer Cape all the way up to north Dakota.

Long wave trough coming in with strong jetstreak around it (which tends to weaken into Sunday at the moment). This gives plenty of mid to upper level shear with winds backing ahead of the front.

Plenty of moisture all the way up the plains.

850 hPa streamlines show strong convergence.

Jetstream (300hPa)

Too early to much detail on it .

[Paul Sherman]

I have been drooling for the past few weeks Pots !!

BTW Next weekend is still looking like a Major event, and i'd expect the SPC To whack a MODERATE Risk straight in for either Saturday or Sunday, and it looks like it could even be a High end Moderate if the Models hold together.

Paul S

Looking Good

Also a Slight Risk for today as well

[pottyprof]

Certainly looking like something should fire Paul. I've been reading the discussion over on stormtrack. Seems to be a feeling that it could be messy MCT's with a few possible Super cells embedded.

Speaking of Super cells.. I found this description of one put together by Craig Maire, one of the trained spotters. Probably the best I've read for it's simplicity..

http://www.easterniowastormchaser.com/Rainbows.html

I think he forgot to rename the page during site development though..

[Nick F]

Looks like the cap is holding nicely over the Panhandle this afternoon, all the ingredients are there in the MDT risk zone for some isolated storms to kick off ahead of the dry line in the moist air over much of the Sern plains East of the distinct dry line that currently runs N-S along the New Mexico and Colorado Ern borders, Plenty of CAPE running up Wern side of TX, OK, KS and NE to tap into.

Strong jet streak aloft Panhandle should ensure storms that do get going later (around 22-23z) should develop into supercells:

Hourly 0-1km Storm relative Helicity and sfc-1km wind shear charts favour NW TX area for perhaps tornado potential later under any supercells:

Chasers favouring the TX panhandle this afternoon for intiation, nice clear skies there atm, Lubbock-Amarillo area a good area to sit it out till something kicks off, maybe a chase towards Childress when things get going.

[Nick F]

Further North of the Panhandle have an equally good environment for suprcells to fire with potential for tornadoes in the afternoon over there, currently a Tornado Watch over central/wern portion of Nebraska, a few discrete cells forming there now over S central NE:

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 154

NWS STORM PREDICTION CENTER NORMAN OK

200 PM CDT SAT APR 21 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

NORTHEAST COLORADO

WESTERN AND CENTRAL NEBRASKA

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 200 PM UNTIL

1100 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 EAST SOUTHEAST OF

IMPERIAL NEBRASKA TO 25 MILES EAST NORTHEAST OF VALENTINE

NEBRASKA. 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.

DISCUSSION...TSTMS EXPECTED TO DEVELOP IN WRN AND SRN PARTS OF WW

OVER THE NEXT 2 HOURS OR SO AS LOW LEVEL CONVERGENCE AND HEATING

CONTINUE ALONG FRONT/LEE TROUGH EXTENDING NE FROM SE CO LEE LOW.

COUPLED WITH ARRIVAL OF INCREASED FORCING FOR ASCENT IN EXIT REGION

OF 80 KT NM MID LVL SPEED MAX...REGION WILL BE FAVORABLE FOR

LONG-LIVED SUPERCELLS. DEGREE OF INSTABILITY...LOW LEVEL VEERING

PROFILES INVOF SW/NE FRONT...AND POTENTIAL FOR SOME STORMS TO MOVE

ALONG THE BOUNDARY SUGGEST A MODERATE PROBABILITY FOR TORNADOES IN

ADDITION TO LARGE HAIL AND POSSIBLY HIGH WIND.

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

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 22035.

[Nick F]

PDS (Potentialy Dangerous Situation) Tornado Watch issued for TX and OK Panhandle ... show me the way to Amarillo

Still waiting for the cap to break though ... will in next hour hopefully. EDIT: Towers going up NE of Amarillo toward OK border.

SEL7

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 157

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT SAT APR 21 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

THE OKLAHOMA PANHANDLE

WEST TEXAS AND THE TEXAS PANHANDLE

EFFECTIVE THIS SATURDAY AFTERNOON FROM 345 PM UNTIL MIDNIGHT CDT.

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

DESTRUCTIVE TORNADOES...LARGE HAIL TO 2.5 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 20 MILES NORTH OF GUYMON

OKLAHOMA TO 10 MILES SOUTHWEST OF BIG SPRING TEXAS. FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU7).

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.

[NL]

Good evening fellow stormchasers ( well virtual )

Well it looks like initiation has started, looking like a serious night

Ive been watchin developments for a few hours now and can't believe the

speed that these build..

[Nick F]

Yes, cells begining to fire along the N-S dry line towards the New Mexico and Colorado borders, Sern tail end West of Amarillo and Lubbock right now:

[NL]

Tornado sig in NE Colorado SW Nebraska.

Sorry that pic dont want to upload!!

Edited April 21, 2007 by Northern Light

[Nick F]

Tornado warnings for TX Panhandle now, aswell as the warnings for Ern CO and Nern NE, great day for chasing with cells firing N-S all along the dry line over Wern side of the High Plains, though which cell do you go for a potential tornado - like a needle in a haystack:

http://www.weather.gov/view/national.php?prodtype=tornado

Supercell bang right over I-40 West of Amarillo has a TVS right now, looks like a slight hook on cell aswell:

[pottyprof]

http://www.kvii.com/weather/radar.aspx?type=sky_cam

Looks a bit black over Bill's mother's...

[Nick F]

Quite an active evening yesterday over TX Panhandle with numerous tornado reports with the dry line storms, Amos Magliocco and fellow chaser were hit by a tornado in the city while in their SUV, they escaped mostly unscathed fortunately:

http://www.stormtrack.org/forum/showthread...2085&page=8

Looks like there was a fair bit of damage in the city, with a car show room levelled and some other brick structures flattened, they are reckoning an EF4 atm.

Here's where Tulia is, between Amarillo and Lubbock on the I-27:

Check out this time lapse video of the Tulia Supercell developing:

http://www.atmo.ttu.edu/walter/Storms.html

[pottyprof]

Nice time lapse there Nick.. You get a feeling for how these baby's spin.. Great find!!

[NL]

Yeah seriously busy yesterday in northern texas, luckly nobody seems

to have lost their lives. Reports of 19 Tornadoes spotted last night..

Fantastic time-lapse photography there Nick good find..