Virtual Storm Chase 2

[pottyprof]

Looks like a nice squall line setting up there Nick..

[Paul Sherman]

Anyone Up for a Flight out to Chase at the weekend!! Only kidding, I wish

DAY 4-8 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0358 AM CDT WED OCT 03 2007

VALID 061200Z - 111200Z

...SEVERE STORMS POSSIBLE SATURDAY...10/06...FROM THE SOUTH CENTRAL

HIGH PLAINS THRU THE MID MO VLY...AND PARTS OF THE NRN PLAINS/UPR MS

VLY...

IT STILL APPEARS PROBABLE THAT A SIGNIFICANT SHORT WAVE IMPULSE/MID

LEVEL JET STREAK WILL EMERGE FROM THE BASE OF THE WESTERN U.S.

TROUGH EARLY SATURDAY. THE SYSTEM IS EXPECTED TO LIFT ACROSS THE

CENTRAL ROCKIES THROUGH THE NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY

REGION BY EARLY SUNDAY. THIS WILL ENHANCE LARGE-SCALE ASCENT IN A

CORRIDOR ALONG/AHEAD OF A SURFACE FRONT ADVANCING EAST OF THE

CENTRAL DAKOTAS/WESTERN NEBRASKA...AND PERHAPS ALONG DRY LINE

SOUTHWARD INTO THE TEXAS PANHANDLE...WHERE STEEP LAPSE RATES AND A

MOIST BOUNDARY LAYER WILL CONTRIBUTE TO WEAK TO MODERATE

INSTABILITY. EVOLUTION OF A DAMAGING WIND PRODUCING SQUALL LINE IS

EXPECTED SATURDAY AFTERNOON AND EVENING...WITH PERHAPS DISCRETE

DEVELOPMENT AS WELL...IN A FAVORABLY SHEARED ENVIRONMENT FOR

SUPERCELLS.

THEREAFTER...DUE TO THE LARGE SPREAD AMONG MEDIUM RANGE FORECAST

GUIDANCE CONCERNING THE PROGRESSION OF THE UPPER TROUGH EAST OF THE

ROCKIES...PREDICTABILITY OF SEVERE POTENTIAL IS LOW.

[Nick F]

Does look good over the next three days Paul for the Nern Plains, sfc low pressure and warm moist Gulf air advecting way North over the mid West ahead of an amplifying trough heading in from the West across the Rockies by the weekend:

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

[Paul Sherman]

Well the last Severe Risk did not Pan out as expected but this little lot looks very good for the next week, more like a Spring Outbreak than a fall Outbreak!

DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0241 AM CDT THU OCT 11 2007

VALID 131200Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CNTRL HIGH

PLAINS...

...CNTRL HIGH PLAINS AREAS...

LOW LEVEL TRAJECTORIES OVER THE CNTRL AND NRN GULF WILL NOT BE

FAVORABLE FOR OPTIMAL LOW LEVEL MOISTURE RETURN THIS PERIOD AND THIS

COULD SERVE AS AN OVERALL LIMITING FACTOR. HOWEVER...SLY LOW LEVEL

FLOW EAST OF LEE LOW WILL MAINTAIN AXIS OF PARTIALLY MODIFIED GULF

AIR WITH DEWPOINTS IN THE MID TO UPPER 50S INTO THE CNTRL PLAINS

BENEATH PLUME OF STEEP MID LEVEL LAPSE RATES. THIS WILL CONTRIBUTE

TO MLCAPE FROM 1000 TO 1500 J/KG. THE MODEST LOW LEVEL MOISTURE

BENEATH THE EML SUGGESTS THE WARM SECTOR WILL PROBABLY REMAIN CAPPED

TO SURFACE BASED STORMS MUCH OF THE DAY. HOWEVER...BY LATE AFTERNOON

EXIT REGION OF CYCLONICALLY CURVED MID LEVEL JET WILL ADVANCE EWD

INTO THE CNTRL HIGH PLAINS. UPPER DIVERGENCE AND MID LEVEL ASCENT

ATTENDING THIS FEATURE WILL LIKELY CONTRIBUTE TO THE DEVELOPMENT OF

STORMS OVER THE HIGHER TERRAIN AND IN THE MORE DEEPLY MIXED REGIME

OVER THE CNTRL HIGH PLAINS. THIS ACTIVITY MAY INTENSIFY AS IT

SPREADS EWD INTO THE MOIST AXIS. DEEP LAYER SHEAR PROFILES WILL

SUPPORT SUPERCELLS WITH POTENTIAL FOR LARGE HAIL AND ISOLATED

DAMAGING WIND.

OVERNIGHT STORMS ARE EXPECTED TO INCREASE NORTH OF WARM FRONT ACROSS

NEB WITHIN ZONE OF WARM ADVECTION AND LIFT ATTENDING STRENGTHENING

SLY LOW LEVEL JET. THIS ACTIVITY WILL LIKELY BE ELEVATED WITH A

THREAT FOR MAINLY LARGE HAIL.

DAY 4-8 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0414 AM CDT THU OCT 11 2007

VALID 141200Z - 191200Z

...DISCUSSION...

DAY 4 (SUNDAY) UPPER TROUGH WILL CONTINUE EWD INTO THE CNTRL AND SRN

PLAINS. AXIS OF PARTIALLY MODIFIED GULF MOISTURE WILL RETURN NWD

THROUGH THE WARM SECTOR CONTRIBUTING TO DESTABILIZATION DURING THE

AFTERNOON. POTENTIAL WILL EXIST FOR STORMS TO DEVELOP ALONG DRYLINE

AND COLD FRONT WITHIN ZONE OF FAVORABLE LARGE SCALE ASCENT. VERTICAL

SHEAR WILL SUPPORT THREAT OF ORGANIZED SEVERE STORMS.

COLD FRONT ATTENDING SHORTWAVE TROUGH ON DAY 4 WILL LIKELY STALL AND

BEGIN RETURNING NWD AS A WARM FRONT BY DAY 6 AS LEE TROUGHING

DEVELOPS OVER THE PLAINS. THIS WILL ALLOW RICHER MOISTURE TO RETURN

NWD THROUGH THE PLAINS AND MS VALLEY REGION THROUGH A BROADER WARM

SECTOR. DIFFERENCES EXIST BETWEEN THE MODELS REGARDING THE DETAILS

OF THE UPPER PATTERN EVOLUTION. HOWEVER...CONSENSUS IS THAT FETCH OF

MODERATE-STRONG MID-UPPER FLOW AND VERTICAL SHEAR WILL DEVELOP OVER

THE POTENTIALLY UNSTABLE WARM SECTOR...AND POTENTIAL WILL EXIST FOR

IMPULSES TO MOVE EWD THROUGH THIS PATTERN AHEAD OF MAIN UPPER

TROUGH. THIS SETUP WILL CONTRIBUTE TO A THREAT OF SEVERE STORMS

DURING THE DAY 7-8 TIME FRAME OVER PARTS OF THE PLAINS AND MS VALLEY

REGIONS.

Paul Sherman

[Gorky]

Looks to be a potentially very severe event over the next couple of days, so I might as well bump this thread up :o

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

Day 2 and Day 3 outlooks are both moderate risk and wouldn't be surprised to see a high out of this on either day. I'll be out most of tonight but I'll probably choose a virutal target either last thing tonight or in the morning. anyone else want to have a shot?

[Paul Sherman]

:o Now that is quite rare, a Day 3 outlook of Moderate even in the Spring is pretty rare, they must be pretty sure a possible "Big" Autumn outbreak could occur, like you Nathan will leave it until Tonight or tomorrow afternoon for a Chase Target

Paul S

[Paul Sherman]

Actually upon looking at some Models and data Oklahoma City would do VERY Well to dodge a Major Bullet Wednesday evening!! But anywhere east of I35 Is a good choice for hanging about, rubbish Chase Country in Eastern Oklahoma, North East Ok not much better although I chased the Ok/Ks border in June and for that reason I would say Coffeeville (Ks) for a possible Target at the moment, although this could be subject to change if the Low gets held back when it ejects from New Mexico, there should also be a Cold Core play to the North East of the Low pressure system which should be near to C Kansas (For Low Topped Supercells) As it stands most models have "DAMAGING LONG TRACK TORNADOES" As big possibilities for Tomorrow and Thursday!

Keep an eye on Sunday as well, as another big system could crash into the Plains!

Paul S

[pottyprof]

Might as well post the latest from the SPC. Makes for a good read.

SPC AC 161728

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1228 PM CDT TUE OCT 16 2007

VALID 171200Z - 181200Z

...THERE IS A MDT RISK OF SVR TSTMS WED AFTN/EVE ACROSS MUCH OF

CNTRL/ERN KS AND OK INTO PARTS OF WRN MO/AR....

...THERE IS A SLGT RISK OF SVR TSTMS WED/WED NIGHT SURROUNDING THE

MDT RISK AREA...ACROSS THE CNTRL/SRN PLAINS INTO THE MID MS VLY....

...SYNOPSIS...

THE NOSE OF A VERY STRONG WEST NORTHWESTERLY UPPER JET STREAK OVER

THE EASTERN PACIFIC IS NOW OVERSPREADING CALIFORNIA...AND PROGGED TO

CONTINUE THROUGH THE SOUTHERN ROCKIES BY 12Z WEDNESDAY...AND THE

MIDDLE/LOWER MISSISSIPPI VALLEY BY 12Z THURSDAY. MUCH OF MODEL

GUIDANCE INDICATES THAT...AS THIS OCCURS...STRONG SURFACE

CYCLOGENESIS WILL TAKE PLACE TO THE LEE OF THE CENTRAL ROCKIES...

WITH THE MAIN SURFACE LOW LIKELY TO LIFT OUT OF THE CENTRAL PLAINS

THROUGH THE MIDDLE MISSOURI VALLEY BY LATE WEDNESDAY NIGHT/EARLY

THURSDAY. THIS WILL SUPPORT A NORTHWARD RETURN FLOW OF MOISTURE

FROM THE SOUTHERN PLAINS/RIO GRANDE VALLEY.

RICHER BOUNDARY LAYER MOISTURE OVER THE WESTERN GULF OF

MEXICO...CHARACTERIZED BY LOWER/MID 70S DEW POINTS...WILL PROBABLY

NOT BECOME ENTRAINED INTO THE DEVELOPING SYSTEM OVER THE PLAINS.

BUT...THIS MOISTURE IS EXPECTED TO ADVECT TOWARD THE LOWER

MISSISSIPPI VALLEY/CENTRAL AND EASTERN GULF COAST REGION...AS A

TROPICAL PERTURBATION NOW OVER THE WESTERN GULF OF MEXICO

ACCELERATES NORTH NORTHEASTWARD...AHEAD OF THE DEVELOPING SOUTH

CENTRAL PLAINS POLAR TROUGH.

THE FIRST IN A SERIES OF IMPULSES EMBEDDED WITHIN THE POLAR JET IS

PROGGED EAST OF THE SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS LATE

TONIGHT INTO EARLY WEDNESDAY. AND...AMPLIFICATION OF A LARGER SCALE

TROUGH WILL CONTINUE THROUGH THE REMAINDER OF THE PERIOD AS A MORE

SIGNIFICANT IMPULSE/JETLET DIGS TO THE LEE OF THE CENTRAL/ SOUTHERN

ROCKIES.

...CENTRAL/SOUTHERN PLAINS INTO THE MID MISSISSIPPI VALLEY...

POTENTIAL FOR AN OUTBREAK OF SEVERE STORMS DOES EXIST FOR

WEDNESDAY...INCLUDING THE POSSIBILITY OF ISOLATED STRONG TORNADOES.

MOISTURE RETURN AND LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION

WITH INITIAL IMPULSE ARE EXPECTED TO SUPPORT A RAPID INCREASE IN

CONVECTIVE DEVELOPMENT EARLY IN THE PERIOD...PARTICULARLY FROM PARTS

OF THE SOUTH CENTRAL PLAINS THROUGH THE OZARK PLATEAU REGION. MUCH

OF THIS ACTIVITY LIKELY WILL BE ELEVATED ABOVE A LINGERING

COOL/STABLE LOW-LEVEL ENVIRONMENT ASSOCIATED WITH A WEAKENING LOW/

MID-LEVEL CYCLONE NOW LIFTING NORTHEAST OF THE MID MISSOURI VALLEY.

SOME OF THESE STORMS...MAINLY WHERE STRONGER MID-LEVEL COOLING

CONTRIBUTES TO STEEPER MID-LEVEL LAPSE RATES ACROSS THE SOUTH

CENTRAL PLAINS...COULD CONTAIN SOME LARGE HAIL. HOWEVER...THIS

THREAT MAY DIMINISH AS CONVECTION/CLOUDS AND PRECIPITATION BECOME

INCREASINGLY WIDESPREAD AND DEVELOP NORTHEASTWARD/EASTWARD THROUGH

THE DAY.

THE PROSPECT FOR CONSIDERABLE EARLY CONVECTION...IN CONJUNCTION WITH

LOWER SUN ANGLE/SEASONABLY WEAKER DAYTIME HEATING...PROVIDE

UNCERTAINTY REGARDING THE MAGNITUDE AND EXTENT OF SEVERE THREAT

LATER WEDNESDAY...AND PARTICULARLY WEDNESDAY EVENING/NIGHT.

HOWEVER...IT APPEARS LIKELY THAT A LEAST A NARROW CORRIDOR OF

SURFACE HEATING WILL OCCUR ALONG/JUST EAST OF A DRY LINE EXPECTED TO

CURVE SOUTHEAST/SOUTH OF A DEEPENING SURFACE LOW OVER WESTERN KANSAS

BY 21Z WEDNESDAY. IN THE PRESENCE OF STEEP LAPSE RATES BENEATH A

MID-LEVEL THERMAL TROUGH...MODELS ARE SUGGESTIVE THAT MIXED LAYER

CAPE WILL EXCEED 1000 J/KG...AND THERMODYNAMIC PROFILES WILL BE

CONDUCIVE TO STRONG UPDRAFTS. COUPLED WITH STRONG DEEP LAYER NEAR A

90+ KT WESTERLY 500 MB JET STREAK...THE ENVIRONMENT WILL BE

FAVORABLE FOR SUPERCELLS WITH VERY LARGE HAIL/ LOCALIZED DAMAGING

WINDS. AND...LARGE LOW-LEVEL HODOGRAPHS BENEATH A 40-50+ KT

SOUTHERLY 850 MB JET WILL SUPPORT THE RISK FOR A FEW

TORNADOES...SOME OF WHICH COULD BECOME STRONG ACROSS PARTS OF

CENTRAL/EASTERN KANSAS AND OKLAHOMA.

SEVERE THREAT WILL CONTINUE AT LEAST INTO EARLY EVENING. AND... IF

DESTABILIZATION IS NOT SUBSTANTIALLY IMPEDED BY EARLIER

CONVECTION...SEVERE POTENTIAL COULD CONTINUE NORTHEASTWARD THROUGH

THE MIDDLE MISSISSIPPI VALLEY WEDNESDAY NIGHT. BUT...AGAIN...THIS

IS HIGHLY UNCERTAIN AT THE PRESENT TIME.

...LOWER MS VALLEY/TN VALLEY AND ERN GULF STATES...

UNCERTAINTY ALSO EXISTS...BUT A SEVERE THREAT COULD ACCOMPANY A

LINGERING LOW/MID-LEVEL CIRCULATION LIFTING INLAND OUT OF THE

WESTERN GULF OF MEXICO. INSTABILITY WILL LIKELY BE LIMITED DUE TO

WEAK LAPSE RATES...BUT INLAND ADVECTION OF A MOIST BOUNDARY LAYER

WITH 70F+ DEW POINTS AND STRENGTHENING LOW-LEVEL WIND FIELDS/SHEAR

COULD SUPPORT THE RISK FOR ISOLATED TORNADOES/DAMAGING WINDS.

..KERR.. 10/16/2007

[Hilton]

It's going to be a fun day!

[Nick F]

Incredible!!! Three MDT risk days

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

... this would be a good week in May let alone October, makes me sick having to put up the boring weather here.

Anyway, great set-up today, very strong jet streak ploughing E out of NM and W TX towards OK today where a sfc low will be present later today centred over KS. So some strong deep layer shear likely to allow supercell development. Winds should veer favourably

CIN and decent CAPE means supercells are very likely once cap is broken:

Already been a tornado watch in place for TX Panhandle - in effect until this afternoon (0900 CDT):

Some early action already as a short-wave ejects E-wards across the Sern plains, behind this short-wave, some Negative Vorticity Advection likely to create CINH over the Sern plains this morning, then we see a dry line develop over W TX/OK Panhandle with sfc low over W KS as the 12z UTC (06z CDT) prog shows:

Then later we see a triple point develop over OK as the fronts/dry line and sfc low move East, so this evening we should see some supercells kick off with over-running of an increasingly strong jet, veering wind profiles near the triple pointshould develop strong Low-level wind shear and helicity, could be a dangerous situation if things verify:

I'm going for Ern Oklahoma as a target, Henryetta, OK will be my target East of OK city just North of the I-40 with scope to head East of West or N/S down the H-75.

Here's the outlook for today: http://www.spc.noaa.gov/products/outlook/day1otlk.html

[Paul Sherman]

Tornado Risk for today - Not bad 15% Hatched area

Still sticking with Coffeyville (Ks) as a starting point.

Paul S

Use the Below Link for Live NOAA Radio later, Norman (Ok) could be a good one to tune into if Supercells start firing near to Ok City!

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

[Gorky]

Too many areas to choose from today. I'm tempted east of OKC, but not quite as far as Tulsa. I'll pick Bristow, OK as my start spot, although I could quite have easily gone further North into KS to chase the triple point as it moves up towards Paul's position later today.

[pottyprof]

And we're off.. First tornado watch of the day.. B)

TornadoWatch - 2100

WWUS20 KWNS 171249

SEL8

SPC WW 171249

OKZ000-TXZ000-172100-

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 708

NWS STORM PREDICTION CENTER NORMAN OK

745 AM CDT WED OCT 17 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

SOUTHWEST THROUGH CENTRAL AND NORTHEAST OKLAHOMA

WESTERN NORTH TEXAS

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 745 AM UNTIL

400 PM CDT.

TORNADOES...HAIL TO 1.5 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 65 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 55 MILES SOUTHWEST OF ALTUS

OKLAHOMA TO 10 MILES SOUTHEAST OF TULSA OKLAHOMA. FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU8).

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 706...WW 707...

DISCUSSION...SLIGHTLY ELEVATED TSTMS/SUPERCELLS FORMING IN AREA OF

ASCENT AHEAD OF STRONG NM SHORTWAVE TROUGH EXPECTED TO PERSIST AND

POSSIBLY STRENGTHEN AS LOW LVL MOISTURE INFLOW CONTINUES ACROSS

REGION. WHILE SFC HEATING WILL BE LIMITED...COMBINATION OF WEAK MID

LVL COOLING...LOW LVL MOISTENING AND INCREASING LARGE SCALE ASCENT

MAY ALLOW STORMS TO BECOME INCREASINGLY SFC-BASED. STRENGTH OF LOW

LVL DIRECTIONAL SHEAR /EFFECTIVE SRH TO 300 MR PER S2/ AND LOW LCLS

SUGGEST POTENTIAL FOR TORNADOES IF STORMS DO INDEED STRENGTHEN AND

BECOME SFC-BASED.

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

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

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

450. MEAN STORM MOTION VECTOR 23040.

...CORFIDI

[pottyprof]

Nice line of severe thunderstorm warnings appeared now.

OK City soon to be surrounded..

According to KFOR.. ( http://www.kfor.com ) There are currently 3 areas of rotation showing on doppler.. This could be an interesting day..

Doppler currently showing a tornado NW of Stillwater.. Nothing yet on NWR so could be in development stage...

[Paul Sherman]

Tornado Watch Boxes going up now, a few areas of Interest being SW Oklahoma and South East Oklahoma eastwards at present, should kick off in the next few hours

Paul S

[Paul Sherman]

Nice Line of Discrete Looking Cells firing off to the South West / West & North West of Ok City, some have crossed into Kansas as well just west of Medicine Lodge, just heard a warning come through on the Radio for one of these Storms near to Canadian for 60mph Winds.

Paul S

[pottyprof]

Looks like a patchwork quilt...

First tornado warning for louisiana/arkansas border.....

[pottyprof]

Latest sat and IR pictures

[pottyprof]

Latest warnings and radar..

[Paul Sherman]

Quick Update

Storm just missed OK Metro are, now to the North was Severe Warned, but no rotation noted, Indiana has a Tornado warned Supercell (Looks Nice on Radar) where did that one come from!!

All eyes now to the South of Oklahoma City along the I35 Corridoor, If Supercells Fire by about 00-01z they should quickly become Severe and Discrete, these have the capabilities to quickly produce Tornadoes at the Start of their Life Cycle.

Would now blow off the Storm just to the North of Ok City and head down I35 Towards Ardmore where the last chance before Nightfall comes to bag a Daylight Tornado!

Paul S

[Paul Sherman]

Absolutely Beautiful Cell just Fired right on the Red River OK/TX, This one is discrete and could go on the rampage!!

New warnings coming through on the Weather Radio!!

Paul S

Tornado warning out for another cell on the Kansas/Nebraska Border now, Potty where is your Virtual Lear Jet!!

Paul S

[pottyprof]

Amazing where they came from Paul.. Looking like a good night for lightning photos..

[Paul Sherman]

It's all gone a bit flat though Pots B) This would probably be called a Bust for quite a lot of Chasers. Moderate Risks are like when our Meto Put out Thunderstorm warnings - THE KISS OF DEATH B)

Paul S

**Although I see a Tornado Warning and Possible Hook echo on the rampaging Red River Cell, still all on its own moving towards the Arkansas border!

[pottyprof]

9 tornado warnings a bit flat??? B)

You get spoilt you do.... B)

[Nick F]

Haven't had a look at the action all evening until now -as been out, but looks like the main tornado threats now will be over MO and AR, most the severe storms today seem to have been notable for high wind gusts more than anything else, though there were a few reports of tornadoes over MO, so someone may have got lucky chasing there. A hard one today for sure wrt to best location to chase, so many conflicting signals.