Virtual Storm Chase 4

[Nick F]

New thread ... SLGT RISK over Ern KS, MO and Sern IA tomorrow. Maybe worth targeting somewhere in Ern KS, upper winds, moisture, CAPE and SRH look most favourable in the risk area and where intiation is likely:

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

- SLP/Jet Tues 00z

- Tds and CAPE/LI Tues 00z

- SRH 00z Tues

... think I may target Topeka or Emporia areas.

Potential further south over TX on Wednesday, though not sure upper winds will favour a SGLT yet ... certainly not any higher than SLGT.

[Cookie]

Blimey virtual storm chase 3 was very popular!

storm chase 2 last basically a year, number 3 did just over a month!!

[Nick F]

Hopefully the real storm chase threads that we'll start for each day in the US Storm Chase area in 7 days' time will prove even more popular when we are out there, I'm sure the 1st tour will attract plenty of attention!

When we come back in early June, I'm sure Paul and I will never tire of posting our thoughts in this thread for the rest of the summer, and hopefully it should have a good following!

[Cookie]

Fingers crossed, its been a great read since I stumbled across it, :lol:

[Nick F]

Quite large changes in the SPC outlook overnight, the dryline and triple point much further north across Oklahoma now, it looked redundant further south over TX yesterday, but today it should come into play across OK, tornado risk looks more apparent too than it did yesterday, 5% risk area given. GFS reluctant to break out any ppn across OK and KS - but NAM develops some by 00z:

- prog chart 00z Tues

- MUCAPE 00Z Tues

Weighing it up, think I'll drop further south than yesterday's preliminary target east of Witchita, going to head into north central OK and target Enid.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1252 AM CDT MON APR 21 2008

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NRN OK/SERN-ERN

KS/WRN-NRN MO TO FAR SRN IA...

...SYNOPSIS...

MODELS REMAIN CONSISTENT SHOWING LARGE UPPER LOW/TROUGH IN THE NWRN

U.S./SWRN CANADA WILL EVOLVE INTO AN ELONGATED POSITIVE TILTED

TROUGH WITH TWO SEPARATE CLOSED LOW CENTERS...1) ONE DEVELOPING NEWD

INTO CENTRAL CANADA...AND 2) SECOND LOW SHIFTING SLOWLY SWWD OFF THE

PAC NW COAST. A LEAD WEAK IMPULSE IS EXPECTED TO TRACK ENEWD INTO

THE WRN GREAT LAKES REGION TODAY...WHILE A STRONGER AND FAST MOVING

SHORT WAVE TROUGH MOVES FROM THE GREAT BASIN TO THE CENTRAL HIGH

PLAINS BY 22/00Z...AND THEN NEWD INTO THE UPPER MS VALLEY TONIGHT.

IN THE LOW LEVELS...COLD FRONT ATTENDANT TO LEAD IMPULSE AND CENTRAL

CANADA CLOSED LOW WILL SPREAD EWD ACROSS UPPER MS VALLEY THIS

FORECAST PERIOD...WITH SRN EXTENT SPREADING SSEWD INTO NWRN MO TO

NWRN OK BY LATE THIS AFTERNOON.

...SRN PLAINS TO LOWER MO VALLEY REGION...

00Z GFS/NAM HAVE COME INTO BETTER AGREEMENT WITH THE MOVEMENT OF THE

COLD FRONT SSEWD THROUGH THE SRN PLAINS THIS AFTERNOON. THIS

BOUNDARY IS EXPECTED TO EXTEND FROM THE TX PANHANDLE NEWD THROUGH

NWRN OK TO ERN KS/NWRN MO TO CENTRAL IA BY LATE AFTERNOON.

MEANWHILE...A DRY LINE WILL MIX EWD INTO WRN OK AND CENTRAL TX THIS

AFTERNOON BEFORE RETREATING WWD SOME TONIGHT. SWLY LOW LEVEL FLOW

LOCATED OVER THE WARM SECTOR THIS MORNING IS FORECAST TO BACK TO SLY

DURING THE AFTERNOON IN RESPONSE TO APPROACH OF GREAT BASIN SHORT

WAVE TROUGH. THIS WILL RESULT IN NWD MOISTURE RETURN WITH SURFACE

DEWPOINTS IN THE MID 60S SPREADING ACROSS MUCH OF OK AND WRN AR EAST

OF THE DRY LINE...WHILE UPPER 50S DEWPOINTS REACH INTO CENTRAL PARTS

OF IA ALONG COLD FRONT.

SWLY FLOW LOCATED ABOVE THE BOUNDARY LAYER WILL MAINTAIN A STRONG

EML ATOP THE MOISTURE RETURN...WITH STEEP MID LEVEL LAPSE RATES

CONTRIBUTING TO MODERATE INSTABILITY WITHIN THE WARM SECTOR FROM THE

SRN PLAINS NEWD INTO SRN/ERN KS TO WRN MO. THIS EML IS EXPECTED TO

CAP THE WARM SECTOR FOR MUCH OF THE AFTERNOON AND LIKELY PRECLUDE

SURFACE BASED TSTM DEVELOPMENT UNTIL THE ARRIVAL OF FORCING FOR

ASCENT WITH SHORT WAVE TROUGH MOVING NEWD THROUGH THE CENTRAL PLAINS

THIS EVENING. HOWEVER...GIVEN DEGREE OF INSTABILITY /MUCAPES

APPROACHING 2500 J/KG/...DEEP LAYER SHEAR AROUND 40 KT AND

CONVERGENCE AT THE TRIPLE POINT...THE POTENTIAL FOR AT LEAST

ISOLATED TSTM DEVELOPMENT MAY OCCUR LATE THIS AFTERNOON /AFTER 21Z/.

IF STORMS DEVELOP DURING THAT TIME FRAME...ISOLATED SUPERCELLS WOULD

BE LIKELY WITH ATTENDANT THREATS FOR A FEW TORNADOES AND LARGE

HAIL...SOME VERY LARGE...GIVEN THE FAVORABLE THERMODYNAMICS AND

KINEMATICS.

OTHERWISE...AS THE SHORT WAVE TROUGH TRACKS NEWD THROUGH THE CENTRAL

PLAINS TO UPPER MS VALLEY THIS EVENING/OVERNIGHT...TSTMS SHOULD

DEVELOP NEWD ALONG THE COLD FRONT INTO ERN KS/WRN MO AND IA.

ALTHOUGH STRONGEST DEEP LAYER SHEAR SHOULD REMAIN OVER THE POST

FRONTAL ENVIRONMENT TONIGHT...MORE SUBSTANTIAL MOISTURE RETURN INTO

SERN KS/WRN MO COMBINED WITH MODEST DEEP LAYER SHEAR SHOULD SUPPORT

THE POTENTIAL FOR STRONG TO SEVERE TSTMS.

[Mesosphere]

well i think i'll pick my target :-

I'll Go for Nowata , Oklahoma

[Paul Sherman]

Tough one Today, Going to go with OKARCHE[/b] Which is NW Of Oklahoma City, if we were there that is where I would sit early grabbing data as things could change quickly today, obviously great road options from there to re-position if the need be.

Biggest chance of a Total Bust is in Oklahoma today as the Cap is pretty strong, NAM Does break out Precip around 00z so a Chance of a Supercell or 2 before daylight fades.

Wednesday IMO Looks the better day for prospects for Tornadoes!

Paul S

[NL]

After much deliberation i've decided to start in Seiling, Oklahoma. Hope sfc temps can get high enough to bust cap

and have you all brought armour plating and helmets? as huge hail can be expected with any developing supercells. :o ...

Dont know if i'll be able to follow this evenig as i'm off to Northumberland again today, depends if i can find a free wi-fi

connection. .

[Hilton]

We will be heading somewhere NW of OKC at 3pm today (busy with classes before that). Will try and report back later with a more definite spot.

[Paul Sherman]

If the Models continue to look great on the next runs then Wednesday could very well be Upgraded to a MODERATE Risk, only fly in the ointment is the possibilities of Elevated and Ongoing convection from Tuesdays Text risk near the lifting Warm Front. This Chase on Weds will be in the best Chase Terrain in the World eg Tx Panhandle from Lubbock up to SW Kansas, would love to get one of these on our trip starting next week.

Early Target for Wednesday would be Amarillo after a nice trip to the Big Texan tomorrow Night B)

[Paul Sherman]

Southern Oklahoma looking likely to see the 1st Cells of the day soon by the looks of things. Agitated Cumulus Field and Dryline Bulge is evident along and just west of I35 Near Ardmore and the Red River, ML Capes of 4,000jkg and South Easterly Surface winds making this area look tasty at the moment, I would think a lot of the Chasers could be out of position if this goes bang!

Paul S

[Nick F]

Yes, south central OK has the best SR helicity values and wind shear vectors over the state too - with sfc winds most strongly backed towards SE here. SPC has reduced the tornado prob. from 5% to 2% on latest update though, so there maybe little in the way of tornado reports. Just waiting for the cap to break somewhere! Some big hailers even if no tornadoes.

[Cookie]

update

from yesterday

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

there were 9 Tornado Reports Yesterday*| Today | Storms | Hail | Wind

Time (Z) 	Strength 	Location 	County 	State 	Lat 	Lon 	Comments
1809 	UNK 	ST CHARLES 	CHARLES 	MD 	38.61 	-76.92 	BELOW
EF0 TORNADO AS DETERMINED BY NWS SURVEY OF DAMAGE TO TOWNHOMES AND OUTBUILDINGS. (LWX)
1837 	UNK 	CHILLUM 	PRINCE GEORGES 	MD 	38.96 	-76.99 	BELOW
EF1 TORNADO AS DETERMINED BY NWS SITE SURVEY WITH DAMAGE TO ELEMENTARY SCHOOL AND CONSTRUCTION TRAILER BLOWN OVER. (LWX)
1936 	UNK 	2 E BOTTOMS BRIDGE 	NEW KENT 	VA 	37.51 	-77.16 	BELOW
ALUMINUM SIDING BLOWN 100-200 FT FROM A BARN IN THE 1900 BLOCK OF QUAKER ROAD. TORNADO PATH LENGTH ESTIMATED AT 300 FT...WIDTH AT 50 FT. TOP WINDS WERE ESTIMATED BETWEE (AKQ)
1945 	UNK 	RIVER ROAD 	BEAUFORT 	NC 	35.51 	-76.99 	BELOW
REPORTS OF TORNADO ON THE GROUND NEAR SHADY BANKS (MHX)
1945 	UNK 	2 W WESTWOOD 	HANOVER 	VA 	37.6 	-77.21 	BELOW
FOUR MILE BROKEN PATH OF EF0 TORNADO DAMAGE IN EASTERN HANOVER COUNTY...ABOUT 7 MILES EAST OF MECHANICSVILLE. DAMAGE MOST EXTENSIVE ALONG MCCLELLON ROAD...BETWEEN WESTW (AKQ)
1958 	UNK 	10 NE MECHANICSVILLE 	KING WILLIAM 	VA 	37.73 	-77.23 	BELOW
POSSIBLE TORNADO REPORTED EAST OF MECHANICSVILLE. BARN DAMAGED AND MULTIPLE TREES DOWN. (AKQ)
2038 	UNK 	CHOCOWINITY 	BEAUFORT 	NC 	35.51 	-77.1 	BELOW
NUMEROUS TRAINED SPOTTERS SAW BRIEF TORNADO TOUCH DOWN (MHX)
2225 	UNK 	2 S CENTRAL GARAGE 	KING WILLIAM 	VA 	37.72 	-77.13 	BELOW
POSSIBLE TORNADO SIGHTED. SEVERAL UTILITY TRAILERS DAMAGED AND MULTIPLE TREES DOWN. (AKQ)
2305 	UNK 	6 SSE LEWISTON WOODVILL 	BERTIE 	NC 	36.03 	-77.14 	BELOW
BRIEF EF0 TORNADO TOUCHDOWN OFF OF BILLIES CLUB ROAD. DAMAGE PATH AND WIDTH ESTIMATED AT 40 YARDS...WITH NUMEROUS DOWNED TREES IN SWAMP. (AKQ)

[Nick F]

Nearly 6pm Sern Plains time and still the cap holding firm ... better do something soon! Could be a bust for many if it doesn't and maybe the GFS was right afterall in not breaking out ppn over OK!

Interesting streak of high cloud over NW/W TX ATM though, could mark an upper level disturbance/shortwave ejecting NE towards Red River/SW OK.

[Roger J Smith]

Some of you are arriving Sunday 27th, am I right?

Looks like a strong cold front moving rapidly southeast through DFW mid-afternoon. Hope you're on the ground before then, of course timing at this range not that accurate.

After that, would expect the first week to be mainly a high plains west Texas scenario, after perhaps a swing down to south around San Antonio to catch any frontal activity left over Monday. Looks to me like a hot, dry set-up over west Texas for the first few days of your chase with some chance of at least isolated cells perhaps as far north as central CO and w KS.

It is going to be up around 35 C and bone dry, by the looks of it. The colder air available is extremely cold now that there is a foot of snow back on the ground in Alberta and Saskatchewan. If the flow buckles later in week one, all hell could break loose with most of this snow sticking around for quite a while and feeding into -6 to -10 C dew points in any cold air masses heading south. If that stuff gets wrangling with Gulf air, I would not want to be in the way, unless I was with Paul and the Baron.

[Nick F]

Looks like a few isolated TSTMS managed to break the cap over Sern OK last night - and merged into a supercell. No tornado reports, but some large hail greater than 2.5" smashed some windscreens on cars according to reports.

A SLGT risk over NW TX/TX panhandle today, very low risk of tornadoes with weak SR Helicity values given by NAM, but some large amounts of CAPE and triple point looks to move E or SE across the area. Looking at NAM ppn charts and sfc progs suggest triple point will be near Childress, TX at 00z and this is where NAM initiates ppn too, so going for Childress today:

-00z Tues prog

- NAM ppn and 0-1km SR Helicity

Tomorrow looks potentially to be a big day though over the TX Panhandle - with a good tornado potential, much better SR Helicity values which look pretty strong in this area, dry line moving in, could be a MDT in the making this one:

Again will probably place myself somwhere like Childress or maybe further west like Plainview, gonna be a good'n I feel and a shame we're not there now

[Paul Sherman]

Yep

Bit of a Kick in the Teeth seeing these Outlooks for 3 straight days in great chase territory and then pretty much Jack for our arrival and first few days

- Day 1 Tuesday 22nd April

- Day 2 Wednesday 23rd April

- Day 3 Thursday 24th April

Thats the way the cookie crumbles unfortunately!

Paul S

[Hilton]

Ended up not having to leave Norman to see the storm in the end, very civilized! The first few pictures were just before it had warnings on it (it had spent an hour sending up tower after tower with each one breaking through a bit more than the last), and then the slightly blurry lightning shot was from our balcony as it passed just south of Norman.

[Cookie]

brilliant images mate

[Paul Sherman]

LOL

Think this is what SPC Call covering their arses, MD's a plenty!

Great Pics btw from Yesterday!

Paul S

[Roger J Smith]

It may turn into a search for back-door cold front activity moving southwest through NE into KS and eastern CO at times in the first few days, or isolated TRW+ over the Big Bend area in a weak SE'ly monsoonal pattern.

I think activity should pick up near the end of the first week of the chase, as heights build over eastern Canada this should remove the current series of weak troughs and carve out a larger trough near 100 W.

[Paul Sherman]

It may turn into a search for back-door cold front activity moving southwest through NE into KS and eastern CO at times in the first few days, or isolated TRW+ over the Big Bend area in a weak SE'ly monsoonal pattern.

I think activity should pick up near the end of the first week of the chase, as heights build over eastern Canada this should remove the current series of weak troughs and carve out a larger trough near 100 W.

Yes

That seems a possible outcome Roger and one I would like to see because once one of the systems comes in at that latitude then a train appear, dont mind a few days of Upslope though, nice gentle 10mph storms :lol:

Paul S

[Paul]

Tornado warning out in missouri this evening

http://www.netweather.tv/index.cgi?action=usalerts;sess=

[Cookie]

I didn't realizes that map came with alerts as well nice one

[Nick F]

One very long dryline progged for 00z Tonight (18z mid-west), stretches from NE Wyoming down to the Big Bend area in west Texas.

For today's target, I'm drawn to west central TX by an apparent dryline bulge being shown by NAM/ETA around the I-20 area:

Some very favourable 0-3km and 0-1km SR Helicity values over the Big Spring to Abilene area, also further north over SW KS and OK Panhandle:

Therefore, given the good MUCAPE/Tds and possible dryline bulge over west central TX, target today will be Snyder, TX.

Pretty gutted this spell of SLGTs isn't happening a week later, because next week, at least the first 3 days are looking appalling over the mid-west looking at GFS this morning.