Day 9 - Discussion

[Paul Sherman]

Another Slight Risk for 6th May - We will be refining our Chase Target after Breakfast

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0745 AM CDT TUE MAY 06 2008

VALID 061300Z - 071200Z

...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FOR A LARGE

PART OF THE GREAT PLAINS...

...SRN PLAINS TODAY THROUGH TONIGHT...

DEEP CONVECTION HAS BEEN MORE WIDESPREAD THAN ANY OF THE OPERATIONAL

OR EXPERIMENTAL HIGH-RESOLUTION MODELS INDICATED

OVERNIGHT...ESPECIALLY ACROSS W/NW TX. THIS HAS PRODUCED A LARGE

AGGREGATE COLD POOL ACROSS A LARGE PART OF KS INTO OK AND THE TX

PANHANDLE/NW TX...AND IMPEDED THE NWD RETURN OF RICHER LOW-LEVEL

MOISTURE ACROSS THE SRN PLAINS. THE REMNANT OUTFLOW BOUNDARY FROM

THE OVERNIGHT STORMS COULD PERSIST INTO THE AFTERNOON ACROSS W TX

AND SERVE AS A FOCUS FOR SEVERE THUNDERSTORM DEVELOPMENT...WHILE

SUBSTANTIAL MODIFICATION OF THE COLD POOL WILL BE NECESSARY FOR

SEVERE STORM DEVELOPMENT FARTHER N ACROSS THE SOUTH PLAINS AND TX

PANHANDLE REGION.

MEANWHILE...THE MID-UPPER LEVEL LOW OVER THE NRN GULF OF CA WILL

PROGRESS EWD ALONG THE INTERNATIONAL BORDER TO FAR W TX AND SE NM BY

THE END OF THE PERIOD. DOWNSTREAM FROM THIS WAVE...LEE CYCLOGENESIS

WILL OCCUR INITIALLY INVOF SE CO...WITH GRADUAL CONSOLIDATION INTO A

PRIMARY CYCLONE INVOF THE SE TX PANHANDLE BY 07/12Z. A DRYLINE WILL

BECOME ESTABLISHED AND MIX EWD FROM ERN NM INTO W TX THIS

AFTERNOON...THOUGH THE OPERATIONAL MODELS APPEAR A LITTLE TOO

AGGRESSIVE WITH THE EWD MOTION OF THE DRYLINE. A CONTINUED INFLUX

OF MID 60S BOUNDARY LAYER DEWPOINTS /FROM S OF THE STALLED OUTFLOW

BOUNDARY/ AND DAYTIME HEATING BENEATH STEEP MID LEVEL LAPSE RATES

WILL CONTRIBUTE TO THE DEVELOPMENT OF MODERATE INSTABILITY E OF THE

DRYLINE /MLCAPE VALUES OF 1500-2500 J/KG/. AT THE SAME TIME...A

GRADUAL INCREASE IN MID LEVEL WSWLY FLOW...AS WELL AS INCREASING SLY

LLJ THIS EVENING...WILL RESULT IN FAVORABLE VERTICAL SHEAR FOR

SUPERCELLS.

WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE

AFTERNOON ALONG THE DRYLINE...IN THE WAKE OF THE MORNING CONVECTION.

BOUNDARY LAYER DEWPOINTS IN THE MID 60S AND EFFECTIVE SRH

INCREASING TO 200-300 M2/S2 BY THIS EVENING COULD SUPPORT A FEW

TORNADIC SUPERCELLS...PRIMARILY FROM SW KS AND THE ERN TX

PANHANDLE/WRN OK INTO W/NW TX...ESPECIALLY NEAR THE INTERSECTION THE

DRYLINE AND ANY REMNANT OUTFLOW BOUNDARY BY LATE AFTERNOON.

OTHERWISE...VERY LARGE HAIL COULD ACCOMPANY ANY OF THE SUPERCELLS.

THE PRIMARY MID LEVEL WAVE WILL BEGIN TO EMERGE OVER THE SRN HIGH

PLAINS LATER TONIGHT. A RETREATING DRYLINE AND THE ARRIVAL OF THE

STRONGER LARGE SCALE ASCENT WILL LIKELY SUPPORT RELATIVELY

WIDESPREAD THUNDERSTORM DEVELOPMENT OVER W TX TONIGHT. THIS

CONVECTION WILL THEN PROGRESS EWD INTO NW TX AND WRN OK DURING THE

EARLY MORNING HOURS...WITH AN ATTENDANT THREAT FOR DAMAGING WINDS

AND HAIL.

...NRN PLAINS INTO THE UPPER MS VALLEY THROUGH TONIGHT...

A MID LEVEL SHORTWAVE TROUGH OVER CENTRAL MT THIS MORNING WILL MOVE

GENERALLY EWD OVER THE NRN PLAINS TO THE UPPER MS VALLEY BY LATE

TONIGHT...WHILE PHASING WITH ANOTHER TROUGH ROTATING AROUND THE

LARGE CLOSED LOW OVER NRN ONTARIO. SURFACE CYCLOGENESIS WILL OCCUR

IN ADVANCE OF THE MID LEVEL WAVE ALONG THE SD/ND BORDER REGION

TODAY...AND THE CYCLONE SHOULD REACH NW WI BY THE END OF THE PERIOD.

MOISTURE RETURN NWD INTO THE WARM SECTOR OF THIS SYSTEM WILL BE

HAMPERED BY THE IMPACTS OF WIDESPREAD CONVECTION OVERNIGHT IN

KS/OK/TX. STILL...BOUNDARY LAYER DEWPOINTS SHOULD RANGE FROM 45-55

F AND AFTERNOON TEMPERATURES IN THE 70S WILL RESULT IN MLCAPE VALUES

OF 500-1000 J/KG.

STEEP LOW-LEVEL LAPSE RATES AND RATHER MODEST INSTABILITY AND

VERTICAL SHEAR IN THE WARM SECTOR SUGGEST THAT LARGE HAIL AND

DAMAGING WINDS WILL BE THE MAIN THREATS WILL CONVECTION ACCOMPANYING

THE SURFACE LOW. VERY STEEP MID LEVEL LAPSE RATES/ GREATER

INSTABILITY SWD INTO NEB ALONG THE TRAILING SURFACE TROUGH SHOULD

SUPPORT LARGE HAIL WITH ANY STORMS THAT DEVELOP LATER TODAY.

[MAF]

hi Paul S and the rest of the gang. been checking out the setup this morning and still looking quiet, so fingers crossed there will be a change in the coming huors for something worth chasing

[NL]

hi Paul S and the rest of the gang. been checking out the setup this morning and still looking quiet, so fingers crossed there will be a change in the coming huors for something worth chasing

When you mean by 'quiet' i suspect you mean no or few tornadoes, certainly wont be quiet

amongst those storms..!!(crash, bang, wallop) Looking better than yesterdays set-up here's hoping you sight a tornado lads..

Latest visible satellite image.

Edited May 6, 2008 by NL

[Paul Sherman]

Chase Target Sorted over Breakfast, going to be heading south on Highway 83 from Liberal down the Eastern Texas Panhandle towards Childress to have lunch there. Looking much better than yesterday for Tornadoes along the Dryline, we will be looking for a Bulge and old OFB (Outflow Boundaries for Initiation) probably wont be much before 00z today.

Paul S

[MAF]

yep, i meant quiet on the tornado front, things changed a bit since last post

forecast for Childress TX

Tonight: Showers and thunderstorms likely, mainly after 1am. Some of the storms could be severe. Mostly cloudy, with a low around 63. Breezy, with a south wind between 15 and 25 mph. Chance of precipitation is 60%.

Wednesday: A 50 percent chance of showers and thunderstorms, mainly before 1pm. Mostly cloudy, with a high near 77. North northwest wind between 10 and 15 mph

hope you get some storm action out of that

[MAF]

this looks good

WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE

AFTERNOON ALONG THE DRYLINE...IN THE WAKE OF THE MORNING CONVECTION.

BOUNDARY LAYER DEWPOINTS IN THE MID 60S AND EFFECTIVE SRH

INCREASING TO 200-300 M2/S2 BY THIS EVENING COULD SUPPORT A FEW

TORNADIC SUPERCELLS...PRIMARILY FROM SW KS AND THE ERN TX

PANHANDLE/WRN OK INTO W/NW TX...ESPECIALLY NEAR THE INTERSECTION THE

DRYLINE AND ANY REMNANT OUTFLOW BOUNDARY BY LATE AFTERNOON.

OTHERWISE...VERY LARGE HAIL COULD ACCOMPANY ANY OF THE SUPERCELLS.

NOAA/SPC VALID 061300Z - 071200Z

[Hilton]

Leaving Norman for Childress in the next 30 mins or so (hopefully via some breakfast!).

[Roger J Smith]

I think Childress is a good target because there is probably a fairly good chance of a developnig chase situation in any direction from there after 18z. Very high thickness values developing for 00z around Amarillo to Dalhart suggest that either side of this line may become focus for tornadic development, either on dry line or stalled P front (leading edge of high dew point tropical air into sw KS and w OK). And/or there could be supercell development somewhat to southwest of Childress after 21z. Whatever does manage to build up will then remain quite severe well into the night as better dynamic forcing arrives with upper low accelerating into the vicinity. Keeping an eye on it although not expecting very rapid development with the moisture field so evenly mixed at present.

[johnholmes]

Chase Target Sorted over Breakfast, going to be heading south on Highway 83 from Liberal down the Eastern Texas Panhandle towards Childress to have lunch there. Looking much better than yesterday for Tornadoes along the Dryline, we will be looking for a Bulge and old OFB (Outflow Boundaries for Initiation) probably wont be much before 00z today.

Paul S

if nothing else Paul and team its improving my USA geography!

[Stu]

My Target is South Eastern New Mexico into Texas - 15z RUC confirms this ...

[NL]

SPC have upgraded their forecast with a moderate risk of severe thunderstorms on the Kansas Nebraska border and now a 10% chance of a tornado around W Texas.

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

Edited May 6, 2008 by NL

[stevestorms]

we are heading Seminoe south of lubbock Tx , good luck teams

[kold weather]

Interesting to see the different ideas that are on option, theres a large slight zone with also a smaller moderate regon that has being upped since last night. Looks like everyone on here is going for the southern option rather then moderate zone, because it seems like the risk of tornadoes is higher in that southern zone, esp in western Texas which seems to be where most people are ready and setting up.

[Gorky]

I'm in Brownfield at the moment. Just seen one Cloud 9 Chase tour go past me. Looks like I may have come too far east in my rush this morning as I slept in real late and had no data this morning. I guess I might end up heading back in pretty much the same way I just came

Edited May 6, 2008 by Gorky

[Roger J Smith]

My current assessment, eastern TX panhandle to far west OK may be good for later tornadic storm development, Lubbock area currently inhibited by widespread low level cloud that will lift slowly this afternoon, dry line pushing into far s.e. NM may trigger before 00z west of Plainview to Amarillo, meanwhile also good prospects sw KS from developing cells in se CO.

If it were me, I would take the chance on staying between Amarillo and Clinton OK where I think the chances of seeing tornadic storms is higher than other areas. Initiation likely around 2030z with max around 23z.

[NL]

Mesoscale Discussion concerning severe potential

MESOSCALE DISCUSSION 0795

NWS STORM PREDICTION CENTER NORMAN OK

0127 PM CDT TUE MAY 06 2008

AREAS AFFECTED...SWRN AND WRN TX THROUGH ERN NM

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 061827Z - 062100Z

STORMS ARE EXPECTED TO DEVELOP ACROSS PARTS OF SWRN TX...INITIALLY

OVER THE DAVIS MOUNTAINS BY MID AFTERNOON AND LATER FARTHER NWD

ACROSS ERN NM BY LATE AFTERNOON. INITIAL PRIMARY THREAT APPEARS TO

BE LARGE HAIL. HOWEVER...THREAT FOR ISOLATED TORNADOES MAY INCREASE

BY EARLY EVENING.

SELY BOUNDARY LAYER FLOW HAS ADVECTED LOW 60S DEWPOINTS INTO SWRN TX

AND SERN NM. HOWEVER...STRONG SURFACE HEATING AND MIXING HAS

RESULTED IN SURFACE DEWPOINTS FALLING TO THE UPPER 50S TO AROUND 60.

SWLY MID-UPPER FLOW DOWNSTREAM FROM UPPER TROUGH CENTERED OVER NW

MEXICO WILL MAINTAIN STEEP MID LEVEL LAPSE RATES ABOVE THE MOIST

AXIS. LATEST OBJECTIVE ANALYSIS DEPICTS MLCAPE FROM 2000-2500 J/KG

OVER SWRN TX INTO SERN NM. VISIBLE IMAGERY INDICATED CUMULUS HAS

BEEN INCREASING OVER THE DAVIS MOUNTAINS WHERE OROGRAPHIC FORCING IS

BEING AUGMENTED BY STRONG DIABATIC HEATING. THUNDERSTORMS INITIATION

MAY OCCUR IN THIS AREA BY 20Z AS THE CAP CONTINUES TO WEAKEN. SWLY

MID-UPPER FLOW WILL INCREASE OVER SWRN TX-SERN NM INTO THE EVENING

AS UPPER RIDGE AXIS SHIFTS EAST AND EXIT REGION OF UPPER JET

ROTATING THROUGH SHORTWAVE TROUGH APPROACHES THE AREA. SELY LOW

LEVEL FLOW VEERING TO SWLY AND INCREASING THROUGH 500 MB WILL RESULT

IN EFFECTIVE SHEAR SUPPORTIVE OF SUPERCELLS WITH INITIAL STORMS. THE

20+ DEGREES LOW LEVEL TEMPERATURE-DEWPOINTS SPREADS AND MODEST LOW

LEVEL HODOGRAPHS SUGGEST LARGE HAIL WILL PROBABLY BE THE MAIN

INITIAL THREATS. HOWEVER...THE LOW LEVEL JET IS FORECAST TO

STRENGTHEN BY EARLY EVENING ALONG WITH LOWERING LCL HEIGHTS...AND

THIS WILL PRESENT AN OPPORTUNITY FOR ISOLATED TORNADOES BEFORE THE

BOUNDARY LAYER DECOUPLES LATER IN THE EVENING.

..DIAL.. 05/06/2008

[NL]

Tornado watch issued by SPC.

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 267

NWS STORM PREDICTION CENTER NORMAN OK

330 PM CDT TUE MAY 6 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

SOUTHEAST NEW MEXICO

WEST TEXAS

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 330 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 50 STATUTE

MILES EAST AND WEST OF A LINE FROM 20 MILES SOUTH SOUTHEAST OF

FORT STOCKTON TEXAS TO 30 MILES NORTHEAST OF CANNON AFB NEW

MEXICO. 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.

OTHER WATCH INFORMATION...CONTINUE...WW 265...WW 266...

DISCUSSION...CU IS INCREASING ALONG SURFACE DRYLINE OVER EXTREME

SOUTHEAST NM. RECENT OBSERVED SOUNDING DATA MODIFIED WITH CURRENT

SURFACE OBS SUGGEST AIRMASS IS GENERALLY UNCAPPED WITH MLCAPE VALUES

OVER 1500 J/KG. A FEW SUPERCELLS ARE EXPECTED TO DEVELOP ALONG THE

DRYLINE WITH A RISK OF VERY LARGE HAIL AND DAMAGING WINDS. A FEW

TORNADOES ARE POSSIBLE THIS EVENING AS LOW LEVEL JET INCREASES.

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 26030.

[pottyprof]

The storm NW of Odessa has just gone severe..

[Roger J Smith]

I've noticed in the past hour that the area of low cloud that was centered over Lubbock has begun to break up and drift north towards Amarillo. I'm expecting the cell train to begin now in a northward direction, and would suggest a location between Clovis and Plainview -- there may eventually be more further east too.

[NL]

The storm NW of Odessa has just gone severe..

Stu Robinson is live streaming nearing this cell Paul http://www.severestudios.com/livechase .. Havent heard off the team dont know their whereabouts. Should imagine not to far away.

[chionomaniac]

My current assessment, eastern TX panhandle to far west OK may be good for later tornadic storm development, Lubbock area currently inhibited by widespread low level cloud that will lift slowly this afternoon, dry line pushing into far s.e. NM may trigger before 00z west of Plainview to Amarillo, meanwhile also good prospects sw KS from developing cells in se CO.

If it were me, I would take the chance on staying between Amarillo and Clinton OK where I think the chances of seeing tornadic storms is higher than other areas. Initiation likely around 2030z with max around 23z.

Thanks for your input Roger. It helps watchers from afar like myself. Can I ask what time zones that you are quoting? Thanks

c

[Roger J Smith]

In my posts,

z = GMT

The Texas panhandle is far western CDT so effectively the local time is five hours behind GMT, or six hours behind BST.

But effectively it is more like six and a half hours behind due to the longitude, if you're trying to work out what part of the daily cycle these storms are in -- and the climatology is that most of these outbreaks flare up around 00z and produce some of their worst severe weather around 01-02z. However, the storms that chasers like better are earlier developers that have better lighting and also less problems with visibility.

Edited May 6, 2008 by Roger J Smith

[chionomaniac]

In my posts,

z = GMT

The Texas panhandle is far western CDT so effectively the local time is five hours behind GMT, or six hours behind BST.

But effectively it is more like six and a half or behind due to the longitude, if you're trying to work out what part of the daily cycle these storms are in -- and the climatology is that most of these outbreaks flare up around 00z and produce some of their worst severe weather around 01-02z. However, the storms that chasers like better are earlier developers that have better lighting and also less problems with visibility.

Thanks Roger

These storms just fire up too late for me!! Bedtime beckons. However I look forward to hearing all about them tomorrow.

c

[NL]

Tornado warnings on the cell just approaching Odessa TX.

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX

514 PM CDT TUE MAY 6 2008

THE NATIONAL WEATHER SERVICE IN MIDLAND HAS ISSUED A

* TORNADO WARNING FOR...

SOUTHERN CRANE COUNTY IN WEST TEXAS...

EXTREME NORTH CENTRAL PECOS COUNTY IN SOUTHWEST TEXAS...

* UNTIL 545 PM CDT

* AT 512 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 6 MILES WEST OF

CORDONA LAKE...OR 17 MILES SOUTHWEST OF CRANE...MOVING EAST AT 36

MPH.

* THE TORNADO WILL AFFECT THE FOLLOWING LOCATIONS...

CORDONA LAKE...

CRANE...

A TORNADO MAY FORM AT ANY TIME... TAKE COVER NOW. ABANDON MOBILE

HOMES AND VEHICLES FOR MORE SUBSTANTIAL SHELTER. AVOID WINDOWS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT TUESDAY EVENING

FOR SOUTHEAST NEW MEXICO AND SOUTHWESTERN TEXAS.

[Rustynailer]

A lot of chasers are near the other storm at Seminole, sods law, but perhaps it will come up with the goods too.

Qdessa is the place. This is 10000000000 times better than TV....Riviting!

Edited May 6, 2008 by Rustynailer