Chase 2010 - Day 18 Discussion

[Nick F]

Low moving over the Big Bend area of SW TX/Nern Mexico today will drag increasingly moist air in from SE with a warm front lifting north towards TX Panhandle and across Sern New Mexico, while a dryline sets up over far SW Texas/Pecos area.

Two plays really across SW Texas and far SE New Mexico ... either head way southwest to Fort Smith and see what forms on the dryline and upslope or if not willing to drive that far, play the warm front moving north, so perhaps targeting Odessa to Seminole kind of area of SW Texas. Road options are pretty sparse I believe arounD Ft Smith, but better around southern end of the Panhandle to Odessa.

WRF precip charts for 00z (18z CDT):

CAPE and 0-3km SR Helcity charts point to far SW option south of Pecos towards Ft Davis seeing best potential perhaps for a tornado, but anywhere down that area up to Odessa seem to have sufficient dynamics for rotating supercells capable of producing an isolated tornado, though SPC only have 2% probs. Very large hail will be something to watch out for too.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1218 AM CDT FRI MAY 14 2010

VALID 141200Z - 151200Z

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

NM/W TX...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID-SOUTH TO THE

MID-ATLANTIC REGION...

...SYNOPSIS...

STRONG SERN STATES UPR RIDGE WILL FLATTEN AS THE MID-LVL WAVE OVER

THE UPR GRTLKS TURNS EWD TOWARD WRN NEW ENGLAND BY FRIDAY NIGHT.

UPSTREAM ENERGY DIGGING INTO THE MEAN WRN STATES TROUGH POSITION

WILL EJECT ENE FROM THE SRN GRT BASIN TO THE CNTRL/SRN HIGH PLAINS

LATE FRIDAY. AHEAD OF THIS FEATURE...LOWER AMPLITUDE WAVES WILL

MIGRATE NEWD FROM THE WRN GULF COASTAL AREA INTO THE LWR MS VLY

DURING THE PD.

IN THE LWR-LVLS...THE CDFNT FOLLOWING THE NRN-MOST TROUGH WILL

SETTLE SLOWLY THROUGH THE MID-ATLC REGION...CNTRL APLCNS AND THE TN

VLY/MID-SOUTH FRIDAY AFTN/NIGHT. TAIL-END OF THIS FRONT WILL

CONTINUE SWWD INTO THE SRN HIGH PLAINS OF NM/W TX.

...SRN HIGH PLAINS OF NM/W TX...

LLVL MOISTURE WILL CONTINUE TO FLOW INTO FAR W TX AND SERN NM

FRIDAY...PROBABLY FARTHER W THAN SHORT-TERM MODELS SUGGEST OWING TO

CONVECTIVE OUTFLOW/UPSTREAM FALLING PRESSURES. DIFFERENTIAL

HEATING...SELY MOIST UPSLOPE FLOW AND WEAK UPR SUPPORT ALONG SRN

FRINGES OF THE APCHG TROUGH WILL BE FAVORABLE FOR TSTM DEVELOPMENT

ALONG THE HIGHER SW TX/SE NM TERRAIN DURING THE AFTN. MLCAPES ALONG

THE ERN SLOPES WILL LIKELY REACH 2000-2500 J/KG AND WITH WEAKENING

CINH AND ROUGHLY 35-40 KTS OF DEEP LAYER SHEAR... SUPERCELLS WILL BE

LIKELY AS STORMS MATURE TOWARD THE TRANSPECOS/LWR PLAINS BY EVENING.

VERY LARGE HAIL AND DMGG WINDS CAN BE EXPECTED. ACTIVITY COULD

EVOLVE INTO A LOOSELY ORGANIZED MCS WITH GUSTY/DMGG WINDS ACROSS

PARTS OF THE SRN LOW-ROLLING PLAINS/EDWARDS PLATEAU DURING THE

EVENING WITH ADDITIONAL STORMS POSSIBLY CROSSING THE RIO GRANDE FROM

NE MEXICO.

[Paul]

Early bonus for today - storms moving towards the team's hotel, stream is online

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

[Andy Bown]

Well I can see it's been raining, anyone got a cloth for the lens? LOL.

[NL]

Saw all this brewing 5am (their time) but thought they'd all be still in dream-land after a heavy 'sesh' at the Big Texan with cloud 9, can just imagine them all sitting round the tables swigging bud and shmieneken telling stories just like that scene in Jaws when Quint, Brody and Hooper try to 'out-do' each other..!!

Good luck today, no spider bites or flatties... Oh and watch out for the extremely heavy rain affecting parts of Texas falling at 2" per/hr

[Roger J Smith]

I would hobble down to Hobbs NM or somewhere very close to the southeast corner of NM in TX possibly near Andrews TX. Strongest storms might form southwest of there then drift towards Andrews county.

[Nick F]

Looking ahead for the rest of tour 2, SLIGHT risks tomorrow for W TX and then N-central TX on Sunday ... thereafter looks to be a quiet few days on Monday and Tuesday - with an upper ridge setting in. Then for Wednesday 19th next week ... 12z GFS shows a closed upper low (shown by the circle of lighter oranges/lower heights) moving east across the Mountain West towards the central High Plains:

... a jet speed max rounding the base of this trough exits across TX/OK/KS Panhandles:

... this strong jet exit destabilising moist air returning over the Plains as a surface lee cyclone sets up over the Sern High Plains, some good CAPE values:

Long-way off, but potential showing tonight for a severe weather day next Wednesday.

[Roger J Smith]

Rapid development today, there are now four tornado warned cells in an east-west frontal zone through Midland TX ... cells appear to be drifting north. Team appears to be approaching Lubbock and would then be about an hour to two hours from intercepting these cells. May require a route between cells to get on south side of the action for safe viewing.

[Nick F]

Yes, a rash of supercells, some tornado warned, riding the warm front roughly parallel with the I-20 in the Midland-Odessa area:

Pretty early in the day, only just after 2pm!

[Roger J Smith]

Here's the latest radar for the severe storms near I-20. Net-weather team is passing through Lubbock (19z) and heading for Lamesa which is the road junction north of Midland on this radar display.

http://radar.weather.gov/radar.php?rid=maf&product=N0R&overlay=11101111&loop=no

FYI, the weather from Lubbock to this line of cells is uniformly low ceiling winds ENE 15-25 mph with areas of rain, temps will rise slowly from near 15 C in LBB to near 20 C in vicinity of cells. Hot, humid air is just south of the interstate at 19z, with temps near 30 C and dps near 18 C, winds SE 15-30 mph.

Tornado reported near Midland, no damage reports as of this time. Cells are not moving very fast, tornadoes could be rotating around the cells but the warning mentions motion to north at 30 mph on this tornado. The cells in extreme southeast NM look like they could develop to tornadic levels as well.

[MAF]

guys. i am on night shift tonight, so while you are in the supermarket could you

get me a meal please latest from SPC

1700 3 NE RUIDOSO DOWNS

LINCOLN NM 53 FT TRAILER FLIPPED OVER. 500 GAL DIESEL TANK APPROX. 1000 LBS LOFTED APPROX. 100 FT IN AIR. (ABQ)

[Nick F]

Looking at the hourly mesoscale analysis, storms over far SE NM corner-Odessa-Big Spring area right on the northern edge of unstable axis of High CAPE values in the warm sector, as soon as storms move NE over on to the north side of the warm front they will likely dissipate or become elevated, though they seem to be continually self-perpetuating along the frontal boundary:

Looking at the 0-3km SR helicity, bullseye of highest indices right over Midland-Odessa area, they rapidy declining further south, definately the I-20 area near warm front the best area to be atm, with regards to best wind fields for tornadoes:

Think SPC have underestimated the tornado potential for these storms today.

[MAF]

judging by the radar you guys are heading into some heavy stuff shortly

Ian, you looking forward to a new boss when you get back to work?

[Roger J Smith]

Currently seeing two supercells near Odessa and Midland. Team will be approaching Lamesa soon and I would advise take southwest course and try for Odessa region cell, the Midland cell is blocking southeast road option and probably flooding parts of US 87 south of Lamesa en route to tornado warned area there, so access to Odessa cell may be safer and easier. This cell is reported moving northeast at 20-30 mph.

[MAF]

thanks for the report Roger. glad to see you are keeping an eye on the chasers

[Roger J Smith]

MAF, one part of me wishes I were with them, although the other part is quite comfortable to watch through their camera. Just wanted to mention as I'm sure others have noted, the GPS map does not show the current radar (edited in at 2015z) unless you refresh the map. Then the radar updates.

I noted on 20z reports that Lamesa was missing but O'donnell TX (then the current location) was reporting winds N 35 mph and temp only 51 F ... showing that cold air is being downdrafted and pulled back into the circulation.

The Midland area supercell looks like a real monster and I would be hesitant to try going through any part of it. This is why I'm thinking the southwest option from Lamesa is safer (marginally) because there's a bit of a gap between cells and the tornado in that western cell should be moving NNE or NE parallel to TX 349.

Edited May 14, 2010 by Roger J Smith

[Paul]

Hi Roger, the gps map has an auto refresh for the radar now (added today).

[MAF]

yes Roger i know what you mean, i too would love to be there rather than watching them. on the other hand i am not sure i would like to be under golf ball size hail and tornado strength winds.

as for refresh, i think Paul has just answered that...cheers Paul

Edited May 14, 2010 by MAF

[Nick F]

Good see the livestream hold up well so far, lets hope it continues to do so when they reach the business end of the storms, i.e. the south side of the storms they are driving through. Looks like they will have to core punch to see anything though.

[Roger J Smith]

Following the GPS I can see that the team has chosen to head SSE on a route that is west of US 87 and should take them safely between cells to the I-20 ... the very large supercell now south of Big Spring TX has left significant flooding in Midland and probably some points east so we may be seeing signs of that at about 2040z when the team approaches the path this cell took. I'm not sure what they're going to do at the I-20, the supercell near Odessa has weakened and is no longer tornado warned but could redevelop. The massive supercell now to their southeast is pulling away and expanding with the tornadic circulation now further south. It might be hard to catch but if they try I imagine they will cross the I-20 rather than heading east on it to get around to its south side. Probably they will be keeping an eye on cells to their west to see if they present better options in 15-30 mins.

That road they are on is pretty quiet so they should make excellent time unless they hit any overflowed drainage ditches ahead. Back to video and radar watching ...

[Nick F]

Yeah, does look like they can sneak between storms.

These storms really are slow-moving and seemed to be anchored to the warm front in the Odessa-Midland area, a big storm just west of Odessa has an interesting signature on radar and wouldn't be surprised if it becomes tornado warned soon if not already:

[Nick F]

CG lightning in the distance on the livestream as the team park up.

[Ross B]

The stream is perfect, can't ask for any better than that.

Scud or funnel behind the telegraph pole?

Edit: I vote scud, but can't really see it.

Thats a lot of flooding!

[Paul]

Much flooding on the stream at the moment!

[Nick F]

Yes, alot of surface water there!

Looks like the team are headed south of the I-20, to prevent getting cored by the cell just to the W/NW towards Midland.

[Muffelchen]

It is gy wet there: did you see the spray from the puddles (lakes?) they went through? The field either side are like gravel pits there is so much water.

FC reported in the cell to the west of Odessa.