Virtual Storm Chase 3

[Nick F]

For those wanting to play the dryline, like yesterday over SW OK, you maybe better off in North Central Texas by the looks of the things, the dry-line looks like moving east across nern TX and not any further north due to the cold front lying SW to NE across central OK ... storms kicking off from south central to NE OK forming along the cold front - so likely to be squall line in nature. Still fancy getting on the tail end of the squall line somewhere over south central OK though - as this area most likely to see tornadoes over OK.

[Gorky]

NE TX/ SE OK still look like they are in line for the worst of the storms. The Dry line storms forming in TX will be moving into very favourable conditions for tornadoes. I'll probably make my move south of the Red River down towards Paris. Already a TVS on the storm heading towards Dallas and it wasn't sever warned 15 minutes ago.

[Nick F]

Think anywhere S of the I-40 and E of the I-35 in SE OK is looking to see the best potential for supercells with tornadoes according to NOAA radio, hail upto baseball size too. Dry line likely to form more discrete supercells over north central and NE TX too. DFW area about to get clobbered by a line of storms riding the dry line:

[Nick F]

Paul Sherman will be pleased with the latest tornado warning!!!

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE TULSA OK

246 PM CDT MON MAR 31 2008

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* TORNADO WARNING FOR...

SOUTHEASTERN OKFUSKEE COUNTY IN EAST CENTRAL OKLAHOMA

SOUTHERN OKMULGEE COUNTY IN NORTHEAST OKLAHOMA

NORTHWESTERN MCINTOSH COUNTY IN SOUTHEAST OKLAHOMA

* UNTIL 330 PM CDT

* AT 243 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 3 MILES EAST OF

WELEETKA...MOVING NORTHEAST AT 40 MPH.

* SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...HENRYETTA...

DEWAR...SCHULTER...GRAYSON AND HOFFMAN.

IF YOU ARE NEAR THE PATH OF THIS STORM...TAKE COVER NOW! IF NO

UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE

LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE

SUBSTANTIAL SHELTER. AVOID WINDOWS!

LAT...LON 3546 9562 3528 9608 3540 9620 3566 9577

TIME...MOT...LOC 1946Z 239DEG 38KT 3537 9605

$$

[Paul Sherman]

:lol:

I am going for a Double Nick!!

Just hope I dont use up all my Forecasting now, this side of the Pond!!

See ya tomorrow with Mr Fish for the Mammoth Drinking Session!

Paul S

[Nick F]

Tornado warning issued recently for Lake Texoma area of extreme south central OK - just SE of Ardmore towards TX border - waterspout anyone?!

000

WFUS54 KOUN 312147

TOROUN

OKC013-069-095-312215-

/O.NEW.KOUN.TO.W.0022.080331T2148Z-080331T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE NORMAN OK

448 PM CDT MON MAR 31 2008

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...

NORTHWESTERN BRYAN COUNTY IN SOUTHEAST OKLAHOMA...

SOUTHERN JOHNSTON COUNTY IN SOUTHEAST OKLAHOMA...

NORTHEASTERN MARSHALL COUNTY IN SOUTHEAST OKLAHOMA...

* UNTIL 515 PM CDT

* AT 448 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 4 MILES

SOUTHEAST OF MADILL...MOVING EAST AT 30 MPH.

* THE TORNADO WILL BE NEAR...

CENTRAL LAKE TEXOMA AROUND 450 PM CDT...

CENTRAL LAKE TEXOMA AROUND 455 PM CDT...

LITTLE CITY...EASTERN LAKE TEXOMA AROUND 500 PM CDT...

NORTHEASTERN LAKE TEXOMA AROUND 505 PM CDT...

EXTREME NORTHEASTERN LAKE TEXOMA AROUND 510 PM CDT...

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.

LAT...LON 3421 9654 3404 9648 3400 9680 3410 9681

TIME...MOT...LOC 2148Z 257DEG 27KT 3404 9672

[NL]

Thats me pleased 2 days in a row tornado warned.. beginners luck i'd say..!! lol..

[Cookie]

There have been 4 Tornado Reports Today* | Yesterday | Storms | Hail | Wind

Time (Z) 	Strength 	Location 	County 	State 	Lat 	Lon 	Comments
1615 	UNK 	1 SE PLEASANT HOPE 	POLK 	MO 	37.45 	-93.26 	BELOW
DEBRIS FROM BARN BLOWN UPTO A QUARTER MILE AWAY. ROOF DAMAGE TO NEARBY HOME AND POWER POLE DOWNED. (SGF)
1533 	UNK 	6 SW NEVADA 	VERNON 	MO 	37.78 	-94.43 	BELOW
STORM SPOTTER WITNESSED A TORNADO DAMAGING A HOME ON HIGHWAY BB. (SGF)
1512 	UNK 	1 S MILLER 	LAWRENCE 	MO 	37.2 	-93.84 	BELOW
TORNADO STILL ON THE GROUND AND INTENSIFYING. CONFIRMED DAMAGE...POWERPOLES HAVE BEEN SNAPPED ALONG HIGHWAY 39 SOUTH OF MILLER. (SGF)
1505 	UNK 	1 SW MILLER 	LAWRENCE 	MO 	37.2 	-93.85 	BELOW
SPOTTER OBSERVED A BRIEF TOUCH DOWN. (SGF)

http://www.weathermatrix.net/stormmatrix/tornado/

Edited March 31, 2008 by cookie

[Nick F]

Most of the tornado reports were in Missouri in the end - nothing big. One tornado touched down in Little City, OK near the Nern end of Lake Texoma about 30 miles ESE of Ardmore ... or 40 miles south of Ada my target for the day - so not a bad position in the end had I gone for the right cell:

1505 1 SW MILLER LAWRENCE MO 3720 9385 SPOTTER OBSERVED A BRIEF TOUCH DOWN. (SGF)

1512 1 S MILLER LAWRENCE MO 3720 9384 TORNADO STILL ON THE GROUND AND INTENSIFYING. CONFIRMED DAMAGE...POWERPOLES HAVE BEEN SNAPPED ALONG HIGHWAY 39 SOUTH OF MILLER. (SGF)

1533 6 SW NEVADA VERNON MO 3778 9443 STORM SPOTTER WITNESSED A TORNADO DAMAGING A HOME ON HIGHWAY BB. (SGF)

1615 1 SE PLEASANT HOPE POLK MO 3745 9326 DEBRIS FROM BARN BLOWN UPTO A QUARTER MILE AWAY. ROOF DAMAGE TO NEARBY HOME AND POWER POLE DOWNED. (SGF)

2200 2 SW LITTLE CITY MARSHALL OK 3406 9664 (OUN)

SLGT risk today over SE TX, Sern LA, Sern MS and SWern AL - not very good chase country as it seems to be mostly trees and swamps - especially the further east you go. If I had to go for somewhere - it would be in SE TX somewhere - maybe Crockett.

Tomorrow and Thursday looking better chase day - with a SLGT over Nern TX and SW/S OK.

[kold weather]

Yeah in the end the main threat was a little further east, to be fair that was always going to be likely a little further east with the low level jet streak transfering eastwards during the eveing hours.

No tornadoes near the target but there was some 1 inch hail reported very nearby which would have been good enough for me!

Doesn't look to be that great of a set-up today though there is some directional shear present in the lower 300mbs of the atmosphere there is no sign of a low level jet streak and so whilst there may be supercells about I doubt there will be much in the way of tornadic actvity with them. Cape is reasonable though so once again should get rapidly developing storms, the atmosphere isn't too humid either so at least it shouldn't be a murk-fest.

I'll go to Livingston in Se Texas as well, don't think its going to really matter where about in the risk zone you go today as I think everywhere has about the same chance.

Edited April 1, 2008 by kold weather

[NL]

Tornado spotted 7 mile SE of my target area, details are unknown at this present time, chuffed to bits

to claim the only touchdown in Oklahoma..! If i was there in reality i reckon i would have missed it as i think

i would have gone south into NorthernTexas as cells where firing up there, as whats been said about today's

risk i think my target area today will be Lafayette Louisiana.

[Paul Sherman]

Beautiful Set-Up for Thursday across the Best Chase Terrain in the World. This would be Nirvana if we were out there.

Also a Day 2 Risk in the Southern Panhandle area.

DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0231 AM CDT TUE APR 01 2008

VALID 031200Z - 041200Z

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

PLAINS/ARKLATEX...

...SYNOPSIS...

A POTENTIALLY ACTIVE SEVERE WEATHER EPISODE APPEARS POSSIBLE OVER

THE SRN PLAINS ON THURSDAY AS LARGE SCALE FLOW REGIME UNDERGOES

STRENGTHENING/AMPLIFICATION ACROSS THE MIDDLE OF THE NATION. GFS AND

ECMWF APPEAR TO BE CONVERGING ON THE SPEED OF THE EWD PROGRESSION OF

A SWRN U.S. SHORT WAVE TROUGH THAT WILL SPREAD EAST ACROSS THE

PLAINS THROUGH THE PERIOD ACCOMPANIED BY A BELT OF 70-75KT CYCLONIC

MID LEVEL FLOW. SERIES OF FRONTAL WAVES ARE FORECAST TO TRACK ALONG

DEEP-LAYER FRONTAL ZONE ESTABLISHED FROM THE SRN PLAINS TO THE OH

VALLEY. AS THE TROUGH MOVES EAST LATE IN THE PERIOD...ASSOCIATED

COLD FRONT WILL SPREAD SWD ACROSS THE SRN HIGH PLAINS. DOWNSTREAM

FROM THE TROUGH AND COLD FRONT...A WARM/MOIST AIR MASS WILL BE

TRANSPORTED NWD/INLAND FROM THE GULF AND SOUTH TO THE OH VALLEY.

...TX/OK...ARKLATEX TO MID MS VALLEY...

HEIGHT FALLS WITH THE MID/UPPER LEVEL TROUGH WILL AID SURFACE LOW

DEVELOPMENT ALONG A DEEP-LAYER BAROCLINIC ZONE SITUATED FROM THE SRN

HIGH PLAINS EAST TO THE LOWER OH VALLEY. CURRENT MODEL GUIDANCE

SUPPORTS PANHANDLE TO RED RIVER LOW TRACK THROUGH LATE THURSDAY

EVENING. DRYLINE/COLD FRONT/LOW TRIPLE-POINT EXPECTED TO DEVELOP

WITHIN AN INCREASINGLY UNSTABLE AIR MASS IN A REGION BOUNDED BY

TX/OK PANHANDLES...WRN OK...NWRN TX. AS THE PANHANDLE LOW DEVELOPS

TOWARD THE RED RIVER...STRONG FORCING FOR ASCENT NEAR THE

LOW...DRYLINE...AND FRONT SHOULD CONTRIBUTE TO ORGANIZED TSTM

DEVELOPMENT. SHEAR PARAMETERS WILL STRONGLY SUPPORT ROTATING

DISCRETE STORMS WITH LARGE HAIL...HIGH WINDS...AND POSSIBLY

TORNADOES. INITIALLY DISCRETE ACTIVITY MAY GROW UPSCALE THROUGH LATE

THURSDAY NIGHT WITH SEVERE WEATHER SPREADING EWD/SEWD ACROSS OK/TX

AND INTO THE ARKLATEX/MS VALLEY REGIONS INTO FRIDAY.

IT IS TOO EARLY TO DISCERN THE MESOSCALE FEATURES AND MAGNITUDE OF

THE THERMODYNAMIC PARAMETERS THAT WILL PLAY A ROLE IN DETERMINING

WHERE THE GREATEST POTENTIAL FOR SEVERE STORMS/TORNADOES WILL OCCUR

IN THIS SCENARIO. GIVEN SOME DISCREPANCIES IN TIMING...AND FORECAST

RANGE...A MDT RISK AREA IS NOT WARRANTED IN THIS OUTLOOK. IF LATEST

TRENDS ARE BORNE OUT BY SUBSEQUENT MODEL RUNS...HIGHER SEVERE

WEATHER PROBABILITIES WILL BE NEEDED ACROSS PARTS OF THE SRN PLAINS

IN LATER OUTLOOKS.

Paul Sherman

[Hilton]

Very much looking forward to Thursday!

[NL]

Ingredients will be there, just hope they all come together at the right time..

[Nick F]

SLGT risk later today over Oklahoma, Ardmore for me today, less than 2% risk of a tornado though - with storms looking to have best potential after dark when the low-level jet cranks up, though looks like there could be a few elevated storms with large hail/strong straight line winds.

http://www.spc.noaa.gov/products/outlook/day1otlk.html

Tomorrow looks the biggy though with a MODERATE risk, still haven't decided where to target yet, could be somewhere in north central TX this time to get the dry line:

http://www.spc.noaa.gov/products/outlook/day2otlk.html

[NL]

Yesterdays slight risk was downgraded so not suprisingly no tornado reports, only a

couple of large hail with only 1 being reported in the retracted risk area. I think Kold

was the only virtual chaser to see any 'action' with hail falling in Angelina County

a few miles NE of his target area. Today i will go for Antlers Pushmataha.

[Paul Sherman]

My Head hurts way to much today to even think about a Target area for tomorrow, but it could be quite an outbreak!!

Early indications show the Witchita Falls to Altus line is where the Dryline storms should fire up, this could change and as such will not post a target until tomorrow morning.

I'd expect quite a few large Tornadoes, initiation time going by the NAM & RUC Looking like 21z.

Paul S

[Gorky]

Tomorrow does look potentially serious and has done for at least a week on the charts. The GFS and WRF have both been remarkable consistent over the last week with both painting a big target for today in North Central TX and South Central OK. It looks very likely that the outbreak would continue on into subsequent days also. Hopefully tonights elevated storms will set up some nice boundaries to aid with storm initiation tomorrow so we get some early discrete activity along the dry line. Hopefully we won't get too much mush either in the mornign hours whihc might work against a good setup.

I think a Moderate for Thursday is highly likely also, and would not be surprised to see a high risk tomorrow. The way parameters are at the moment, a HIGH/HIGH/MOD for Thurs/Fri/Sat would not be out of the question! There's obviously a lot which could change in the meantime, but everything is in place for a significant outbreak.

Now that I've cursed any chance of this outbreak from happening, I'll pick Wichita Falls as a starting location also for tomorrow. It should be a nice central location from which to relocate from tomorropw morning.

[pottyprof]

Nath.. There is a moderate for tomorrow (Thursday) mate.. B)

[Bilz]

I'm in Norman, Oklahoma, and have to say this looks like the best opportunity for severe storms I've seen here since arriving last August...baseball hail, 75 mph gusts, tornadoes and flooding are possible, apparently. If the moderate risk box stays as it is, I think some chasing might be in order.

[dogs32]

I'm in Norman, Oklahoma, and have to say this looks like the best opportunity for severe storms I've seen here since arriving last August...baseball hail, 75 mph gusts, tornadoes and flooding are possible, apparently. If the moderate risk box stays as it is, I think some chasing might be in order.

get some good pics if you can

[Nick F]

Had a PM earlier asking on how to virtual storm chase ... here's a basic guide for what to look for for a target:

The game is to choose a chase target for the day, just a bit of fun to see who gets closest to the best storms that day - the ultimate goal is to bag a storm with a tornado.

The first port of call for choosing a target is the Storm Prediction Center (SPC) Convective Outlooks here:

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

... when there is a risk day (SLIGHT/MODERATE/HIGH) the aim is to get a target somewhere within the highest risk box area ... the SPC risk boxes aren't a guarantee that supercells with tornadoes are going to occur exclusively within the highest risk area shown (beit SLGT, MDT, etc.) - sometimes tornadoes will occur outside the areas indicated. But getting yourself in the highest risk areas given is a good start.

So where to target in the highest risk area given? Using the NWP model output is a good start ... the best model for the States for storms is the NAM-WRF, followed by RUC and good old GFS, these models can be viewed on various sites - I tend to use the College Du Page NEXLAB page below:

http://weather.cod.edu/forecast/

... for WRF for example - I click on SP (Southern Plains) in the top bar if the risk area is in that area - then on the left hand side choose SLP/6hr precip. This allows us to see where the heaviest ppn and storms are likely to be in the risk area - ideally you want to be on the SW/S/SE end of the ppn - as most storms tend to move NE, N or E and back build to the SW or S along the dry line or cold front - tornadoes tend to form in storms with an unhindered supply of warm moist air and you want clearer skies to see the storm or potential tornado rather than be obscured by heavy rain. Also, you may want to target an area modelled with sufficient CAPE, CAPE values of >1500 j/kg are ideal. Ideally you need to choose the time of the chart to co-incide with when the storms are most likely to be at their most active i.e. the early evening - so a chart with the time on as 00z (18z southern plains time) would be ideal.

I addition, you may want to look at the 250mb winds - a this will show where the strongest jet level winds will be - the stronger the better, as the strong upper winds vent the storms and prevent the precipation falling back down into the updraft and cutting off the storm's fuel supply and causing the storm to collapse. Also, the left exit and right entrance areas of jet streaks tend to be associated with the development of severe storms due to divergence aloft of upper winds creating a void which has to be filled by air from below - so warm moist is made to converge at the surface and rise as a result. 850mb wind charts show the low-level jet - which is also implied in helping thunderstorms develop, a strong low-level jet often develops by the evening and actually strenghtens overnight helping feed storms with warm moist air from the south. Helicity charts are also a good guide to the low-level conditions that tornadoes require for development (aswell as large CAPE values) - helicity is a measure of rotation in any updrafts created by veering winds at the surface or low-level shear - 1km SRH (storm-relative helicity) charts are predicted values of helicity - the stronger they are the more likely supecells will develop with the potential to drop a tornado.

Looking for the dryline is also a good indicator for where the severest storms may develop, the dryline is the boundary between hot dry air from the desert west and warm moist air from the gulf of Mexico. Each day, if the conditions are right, the line moves east forcing warm moist air upwards along the boundary creating storms, though this is dependant on whether the 'cap' breaks or not, the cap or layer of warm dry air aloft acts a lid on convection and is often associated with the dry line and only breaks if there is a dry line bulge or ground heating is sufficient. The dry line can be found as the orange front with semi-circles on the ADDS surface progs (below) The dry line tends to retreat back west during the night:

Based on some of these charts, I would tend to get on the SWern side of the MDT risk area tomorrow - so maybe the Wichita Falls(TX) to Lawton (OK) area. For map to choose a target - try google maps or similar and type in a state in the risk area.

Good luck!

[kold weather]

Thats a good refresher Nick thanks for that mate.

Thursday is looking very interesting nice storng upper jet streak over the region which is quite widespread as well with the storngest core running right thorugh where the dryline will be set-up. The lower jet streak isn't nearly as strong however but it may well be enough given but there is some direction shear in the lower levels in SW OK and NW Texas with a 90 degree veer between the surface and 850hpa.

I think there is one main risk on the dry line and also a small (probably only 5-10%) in a little area over central western OK where there is a low level jet streak is present. CAPE will be low (GFS progs only 300kjs worth of it) and there will be capping but if its broken I'd have thought any cells would be supercells...however to be fair risk is small and probably not worth chasing.

I'm not entirely sure where I would go want to see the 0z model progs first before making a final call but Frederick is where I would place myself right now, could head SE/NW and NNE pretty easily from there if things kick off a little further away.

[Gorky]

Looks like I may well have cursed it somewhat. All model runs sinc emy last post have been rather worrying downgrades! Still I guess it has as much time to upgrade again!

On the plus side, there looks to be yet another big storm moving in on the horizon for day 7/8

Edited April 2, 2008 by Gorky

[Nick F]

Well the emphasis of the MDT risk area has shifted further east and south - with some inconsistencies between NAM and GFS with breaking out ppn - but I still fancy waiting for the dry-line to intiate some decent supercells during the late afternoon/early evening over N Central TX - the cap should hold sufficiently over north central TX to build up sufficient CAPE for things to really explode and there looks to be adequate surface moisture too. Sfc progs suggest a dry line bulge moving east across north central TX/far south of OK towards I-35 and DFW area at 00z:

Weighing it up, I'm going to go for a target of Jacksboro, TX WNW of the DFW metroplex - and hopefully get some decent supercells firing on the dry-line.