Chase 2010 - Day 42 Discussion

[Paul Sherman]

Okay like the Black Eyed Peas Song ( I Got A Feeling ) That Nebraska is going to finally play ball today, This days looks spookily similar to the 6/6/9 day that dropped the La Grange (Wy) Tornado last year so will be picking off anything that moves ESE Off the Wyoming Mountains.

Starting in McCook but will probably head further towards the NE Panhandle area.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0747 AM CDT MON JUN 07 2010

VALID 071300Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF UT/WY E INTO THE

CNTRL PLNS AND LWR MO VLY...

...SYNOPSIS...

FAIRLY ZONAL FLOW WILL PREVAIL OVER THE LWR 48 THIS PERIOD...IN WAKE

OF AMPLIFIED TROUGH SLOWLY EXITING THE NERN STATES. LOW AMPLITUDE

SHORTWAVE IMPULSE NOW OVER ORE WILL REACH THE NRN RCKYS THIS

EVE...BEFORE CONTINUING E TO THE NRN HI PLNS EARLY TUE.

OTHERWISE...UPR RIDGE WILL LINGER OVER THE SRN RCKYS/SRN HI

PLNS...WHILE WEAK UPR LOW PERSISTS OVER S TX.

AT LWR LVLS...LEE LOW EXPECTED TO SLOWLY DEEPEN OVER ERN CO

TODAY...WHILE ASSOCIATED FRONTAL ZONE EXTENDING ESE INTO CNTRL KS

BECOMES BETTER DEFINED. THE LOW SHOULD BEGIN TO MOVE E/NE ACROSS

NRN KS TONIGHT AS DEVELOPING COLD FRONT...INITIALLY OVER

WY/UT...ACCELERATES S INTO CO.

...CNTRL HI PLNS TO LWR MO VLY THIS AFTN/TONIGHT...

SCTD HIGH-BASED AND/OR ELEVATED TSTMS WITH A THREAT FOR SVR HAIL

LIKELY WILL PERSIST FOR SEVERAL MORE HOURS IN WAA AREA ON EDGE OF

EML...FROM NE CO/SE WY EWD INTO CNTRL NEB/NRN KS. A FEW ELEVATED

STORMS ALSO MAY PERSIST OVER SW KS AND THE OK/NRN TX PANHANDLES

...IN WAKE OF WEAKENING OVERNIGHT MCS NOW IN NE OK.

OTHERWISE...EML SPREADING E FROM THE SRN/CNTRL PLATEAU AHEAD OF ORE

UPR IMPULSE SHOULD EFFECTIVELY CAP MUCH OF THE CNTRL PLNS FROM AFTN

TSTM DEVELOPMENT. AFTN STORMS SHOULD...HOWEVER...FORM IN UPSLOPE

FLOW OVER NE CO...ERN WY...AND WRN NEB...N OF ERN CO SFC LOW.

STRONG INSTABILITY /SBCAPE TO 3000 J PER KG/ WILL

EXIST...REFLECTING...IN PART...SFC DEWPOINTS IN THE 60S F. COUPLED

WITH 50 KT DEEP SHEAR ON SRN EDGE OF THE WLYS...THE STORMS SHOULD

QUICKLY BECOME SUPERCELLS WITH VERY LARGE HAIL AND DMGG WIND.

APPRECIABLE LOW-LVL DIRECTIONAL SHEAR ALSO WILL BE FAVORABLE FOR

TORNADOES.

CONTINUED EWD MOVEMENT OF ORE IMPULSE...AND NIGHTFALL...WILL FOSTER

CONSIDERABLE STRENGTHENING AND BROADENING OF SSWLY LLJ OVER THE

CNTRL PLNS TONIGHT/EARLY TUE. ASSOCIATED WAA ATOP AFOREMENTIONED

FRONTAL ZONE SHOULD SUPPORT EWD DEVELOPMENT OF THE WY/NE CO/WRN NEB

STORMS...AND/OR NEW DEVELOPMENT...OVER CNTRL/SRN NEB LATER THIS EVE.

COUPLED WITH FAIRLY RICH MOISTURE INFLOW /PW 1.75 IN/ AND

INCREASING ASCENT AHEAD OF UPR IMPULSE...THE ACTIVITY LIKELY WILL

GROW UPSCALE INTO A STRONG FORWARD-PROPAGATING MCS. THIS SYSTEM

SHOULD MOVE GENERALLY ESE ACROSS NEB AND PERHAPS NE KS BY 12Z

TUE...WITH SVR HAIL AND POSSIBLY SIGNIFICANT DMGG WIND. PARTS OF

NEB AND NRN KS MAY REQUIRE UPGRADE TO MDT RISK IF EXACT BECOMES MORE

APPARENT

Paul S

[Nick F]

I would head to the CO/WY/NEB tri state border area, certainly in the NEB panhandle anyway. Both 12z WRF/NAM and RUC suggest big bullseye of CAPE and strong wind shear here near triple point, especially along the warm front:

-Tues 00z (18z CDT) synoptic chart

NAM and RUC CAPE at 00z:

NAM and RUC SR helicity at 00z:

convective precip. 00z:

Reasonable chance of a nado in NEB Panhandle into far SE corner of Wyoming - especially towards tri-state corner. I-80 between Kimball, NE and Cheyenne, WY maybe a good bet IMO.

[Paul Sherman]

Cheers Nick!

Yep am going to head towards North Platte then West on I-80 Into the Nebraska Panhandle. This year has been the total opposite to last year, cant remember when we have NOT Had a Slight Risk compared to last year when we could not get one for love nor money.

Am quietly confident of Tornado number 19 for the year today

[Roger J Smith]

I fully expect this to go to high risk later, the super-heated air mass further south will be pushing strongly north towards the warm frontal boundary and storm tops could easily reach 55-60k by 22z ... I think you're in the safest part of this zone, central to northern KS could be seeing some severe development too, but there may be better storm visibility in w NE. The 12z model run still shows a large area of 594 dm thickness over Colorado with the 588 dm contour into extreme southwest NE and the western half of KS, by 00z. These are rarely seen thickness values that you might get over subtropical India before the monsoon sets in, just to give an idea of how volatile this atmosphere will be later today. I notice it is already close to 85 F in the TX panhandle heading for 102+ ... with this expected mod-high risk later, the storms appear likely to keep going all night across much of NE and KS east of the 582 dm thickness contour. I think this will be one of the highlight days of the season.

[Nick F]

This year has been the total opposite to last year, cant remember when we have NOT Had a Slight Risk compared to last year when we could not get one for love nor money.

Yes, an epic run since late April of back-to-back severe weather days to chase this year. Whereas at home non-severe storms have only just started after waiting months. Good luck!

[nsrobins]

A three-core event possibly. Firstly, the upslope initiation in E CO (probably Idalia/Wray, CO area or a tad further south going on RUC cap strength) as the inhibition is breached 21/22Z. Then, drop east or southeast to watch the cells tighten in a more highly sheared (good 75deg directional I see) environ with tor possibilities from 23Z (best guess Benkleman, NE). Modest storm motions around 18kns and 0-3 EHIs approaching 7.00 in target area! Interestingly the deep bulk shear is most impressive in C/N NE but I don't think anything significant will fire up there - cap too strong. And lastly, could be a mega-MCS complex rolling into N KS later tonight.

Good luck.

[ian cameron]

from our overnight stop of McCook we have traveled up to north platte and are now heading west on the I80 to big spring

[Arron]

Good luck again

[multi cellular thunderstorm]

Good luck today, I like Nebraska, that's where it all started for me and Arron last year with our first supercell near Thedford.

Just had a play about in Photoshop...

We can dream!

[Arron]

hehe That high needs shifting 200 miles west please

[Roger J Smith]

Looks to me as though Sterling in n.e. CO might be a good spot to wait for development, there are some cells in s.e. Wyoming but a more promising frontal boundary seems to be setting up just south of the Colorado border with WY and NE, and this is where supercell development seems most likely, as well as further south in the heat trough developing in eastern Colorado. Temperatures are clearly going to top 100 F the next 2-3 hours around La Junta and Lamar, holding around 80 F in the transitional air mass that pretty much straddles Nebraska, so the over-running zone should be close to that boundary. Moisture is abundant for this part of the plains, but there is a weak dry line feature setting up with the superheated air (this is almost like a summer chinook) coming out of the Rockies. I see that feature bulging out to the east of Colorado Springs with a convergence zone assisted by topography running south of the I-70 about 50 miles east of the mountains. This should also set off some convection southwest of Sterling in the next 2-3 hours. Once things get going, a massive MCS is likely to form and move east.

I expect some significant development in about an hour to 90 mins from now or by about 2230z.

[Paul Sherman]

Sitting at Kimball (Ne) with a storm about 50 miles to our North West which is struggling real bad atm. Vortex2 across the road with about 100 of there vehicles..........Hmmm

Must be in the right area i guess LOL

Paul S

[bunny1972]

hi paul sounds like another good day i cant get to watch you guys on the live streaming is it just me or are there problems?

[Paul Sherman]

Hi

We have not got it running unfortunately due to going down from 2 cars to 1. We have not got the Power inverters to run everything what with barons, Grlevel3 and other things, have tried another of the sockets but it keeps blowing the Inverter.

Will keep you updated as often as possible and post the pictures.

Temp 79f Dewpoint 65f - Winds from the SE @ 17mph

Perfect conditions

Paul S

[Roger J Smith]

Paul, I can see some development around Fort Collins CO and I think the stuff to your north will fade while this other east-west line expands, but it should head towards a point just south of where you are now, maybe right on the border where the three states converge or just south of that in Colorado. This cell has just popped up about five miles north of Fort Collins.

[NL]

Tornado watch now in place.

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 281

NWS STORM PREDICTION CENTER NORMAN OK

335 PM MDT MON JUN 7 2010

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

EXTREME NORTH CENTRAL AND NORTHEAST COLORADO

THE NEBRASKA PANHANDLE

EXTREME SOUTHWEST SOUTH DAKOTA

EAST CENTRAL AND SOUTHEAST WYOMING

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 335 PM UNTIL

1100 PM MDT.

TORNADOES...HAIL TO 2.5 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 EAST AND WEST OF A LINE FROM 65 MILES NORTHEAST OF DOUGLAS

WYOMING TO 50 MILES SOUTHWEST OF SIDNEY NEBRASKA. FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU1).

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 280...

DISCUSSION...THUNDERSTORMS WILL LIKELY INCREASE IN

COVERAGE/INTENSITY THROUGH THE AFTERNOON/EVENING ACROSS E/SE WY AS

60+ BOUNDARY LAYER DEWPOINTS SPREAD WWD/NWWD INTO SE WY. EROSION OF

THE EARLIER CLOUDS WILL RESULT IN WEAKENING OF THE CAP FARTHER E

WITH TIME...AND THERE WILL BE SOME POTENTIAL FOR UPSCALE GROWTH OF

INITIAL STORMS INTO AN MCS BY EARLY TONIGHT IN WRN NEB. THE

COMBINATION OF MODERATE INSTABILITY WITH STRONG DEEP-LAYER SHEAR

WILL SUPPORT SUPERCELLS FOR THE FIRST SEVERAL HOURS AFTER

INITIATION. ISOLATED VERY LARGE HAIL AND DAMAGING WINDS CAN BE

EXPECTED WITH THE SUPERCELLS. ADDITIONALLY...A FEW TORNADOES WILL

BE POSSIBLE GIVEN THE RICH BOUNDARY LAYER MOISTURE AND MODEST

LOW-LEVEL SHEAR. LATER THIS EVENING...THE PRIMARY THREATS WILL

TRANSITION TO DAMAGING WINDS AND LARGE HAIL.

......................................................................

WWUS40 KWNS 072134

WWP1

TORNADO WATCH PROBABILITIES FOR WT 0281

NWS STORM PREDICTION CENTER NORMAN OK

0434 PM CDT MON JUN 07 2010

WT 0281

PROBABILITY TABLE:

PROB OF 2 OR MORE TORNADOES : 60%

PROB OF 1 OR MORE STRONG /F2-F5/ TORNADOES : 20%

PROB OF 10 OR MORE SEVERE WIND EVENTS : 50%

PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS : 40%

PROB OF 10 OR MORE SEVERE HAIL EVENTS : 60%

PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES : 50%

PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS : >95%

&&

ATTRIBUTE TABLE:

MAX HAIL /INCHES/ : 2.5

MAX WIND GUSTS SURFACE /KNOTS/ : 60

MAX TOPS /X 100 FEET/ : 500

MEAN STORM MOTION VECTOR /DEGREES AND KNOTS/ : 29030

PARTICULARLY DANGEROUS SITUATION : NO

[Paul Sherman]

Just sitting tight at the moment Roger but cell to our SW Duly Noted, this is moving into a great environment for Tornadoes, the Cap further East is killing storms atm but this is due to not be an issue in the next few hours, could still make the stuff to our North around ScottsBluff but dont want to commit just yet.

Paul S

[Nick F]

Looking at the hourly mesoscale analysis, best 0-3km SR helicity near the CO/NEB/WY tri-state borders area and SBCAPE of up to 4000 j/kg overlapping this area currently so best environment here for a tornado:

[ian cameron]

we are now heading north up the 71 towards a huge cell about 40 miles north of scotts bluff

[ian cameron]

we are now approching the base of the storm north west of scotts bluff

[ian cameron]

Wow

Paul is panting - The Structure on this thing is incredible - Nearly put down a Nado about 5 mins ago

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

Wow

Paul is panting

Shouldn't have run around the car

[ian cameron]

parked up watching 2 cells with hooks on them at the mo looking promising on HY 71 just norht of scotts bluff

Edited June 8, 2010 by ian cameron

[ian cameron]

we went through bridgeport about ten mins ago and all the sirens where on and there was rotation on the road was mentel there is a 3 milw traffic jam of chasers its been a mare of a chase

[dogs32]

we went through bridgeport about ten mins ago and all the sirens where on and there was rotation on the road was mentel there is a 3 milw traffic jam of chasers its been a mare of a chase

I miss all that fun Ian..are you teasing me..lol...we have a Supercell risk..oops TS risk today here..lol..

good luck on your last few days..

Have some baby back ribs on me!!

Ive saved you some Buffalo wings if your still intereested

Edited June 8, 2010 by dogs32