Day 14 Discussion

[Paul Sherman]

From the SPC

...SRN MT/NRN WY INTO SWRN ND/NWRN SD...

COMBINATION OF SFC HEATING AND INCREASING UVV AHEAD OF EWD-MOVING WA

UPR LOW LIKELY WILL LEAD TO TSTM DEVELOPMENT OVER THE HIGHER TERRAIN

OF WRN MT AND NRN ID A BIT LATER TODAY...WHERE SPARSE MOISTURE WILL

LIMIT DEGREE OF DESTABILIZATION. SOMEWHAT GREATER INSTABILITY

/SBCAPE TO 2000 J PER KG/ WILL DEVELOP OVER ERN AND SRN MT...WHERE

STEEP LOW TO MID LEVEL LAPSE RATES WILL EXIST WITH SFC DEWPOINTS IN

THE UPR 40S/LOW 50S F.

CONTINUED EWD MOVEMENT OF UPR SYSTEM AND ASSOCIATED REDUCTION OF CIN

SHOULD ALLOW STORMS TO MOVE/DEVELOP E ACROSS CNTRL MT BY MID TO LATE

AFTERNOON...WITH A THREAT FOR HIGH WIND AND HAIL. OTHER STORMS MAY

FORM LATER THIS AFTERNOON INVOF SFC LOW IN SERN MT/SW ND/NW SD AND

PERHAPS FAR NRN WY. 40-50 KT DEEP SWLY SHEAR ON SERN FLANK OF UPR

SYSTEM...ALONG WITH WEAK BUT BACKED NEAR-SFC FLOW NEAR SFC LOW WILL

CREATE FAVORABLE ENVIRONMENT FOR DISCRETE SUPERCELLS IN THIS

REGION...WITH A CONDITIONAL THREAT FOR TORNADOES IN ADDITION TO

LARGE HAIL/HIGH WIND. THE SEVERE THREAT SHOULD SHIFT FARTHER E INTO

THE DAKOTAS TONIGHT...WHERE UPSCALE DEVELOPMENT INTO AN MCS OR TWO

WILL BE ACCOMPANIED BY A GRADUALLY DIMINISHING POTENTIAL FOR

WIND/HAIL.

Paul Sherman

[Julie Cameron]

hi nice to hear from you, wondered when you was going to rise have a great day x

[Paul Sherman]

Yep

No rest for the wicked, 3 Car convoy today rapidly heading towards Rapid City for Lunch and then hopefully intercept some Supercells, Mount Rushmore is not far so would be great to get a nice picture of the "Presidents Heads" in with something nice weatherwise around it as well. Team leaving in 20 minutes, better get Ian up I suppose!!

Paul S

[NL]

You must love driving Paul..!! Well hoping to see some action today as its been very quiet on the 2007 storm chase forum for the last few days, heading towards Mount Rushmore, just 15-20km further west is the ongoing sculpture of "Crazy Horse" and when completed will be the worlds largest sculpture http://www.crazyhorse.org/.

Anyway good luck on the chase today we will be following..

[pottyprof]

Current location and radar..

Current Satellite image

CAPE levels seem to be highest around the N/S Dakota border from mid afternoon

[Roger J Smith]

No change to my outlook in the day 13 thread. Tomorrow still looking very good, today more isolated but think you are heading in the right direction there. Did you know that the "Devil's Tower" as seen in Close Encounters is just across the border in northeast WY, in case you're only sight-seeing today? But I think you'll have one or two storms building up in that general area, around the Black Hills or possibly a little further west to north.

Maybe they should have a Mount Rushmore II for the four worst presidents. Hmm.

[Julie Cameron]

hi ian spurs r 5th, liverpool 3rd and chelsea 2nd arsenal 4th, have a good day, nice 2 hear from u take care an have fun x

[Nick F]

Starting to see some convection over SErn Wyoming, in response to daytime heating, some storms should drift East into SWern SD later - ahead of cold front moving in from the West.

Strongest deep layer shear from jet streak further West over MT, ID and WY when max heating occurs over South Dakota (00z UTC Mon), so the best parameters for severe weather not overlapping this evening over SD. However, deepening sfc low over the Dakotas and surface heating in warm sector suggest isolated upslope storms are possible in the West of SD - perhaps some drifting over from SE/Ern WY.

Tomorrow looking like an outbreak of storms further SE over SEern SD, NE and KS - SD will be under right entrance of strong jet streak (where Vort max/strong PVA will be present) around 00z UTC Tues - also sfc low would suggest some strong verring of sfc winds:

However, Nebraska probably looking best spot for severe storms ahead and along of cold front moving SE where greatest CAPE in warm sector is likely, though risk of severe weather looks like staying SLGT with vort max further North over the Dakotas which doesn't quite overlap the best moisture/CAPE in warm sector further SE:

[pottyprof]

Latest satellite picture with the NWS warnings show that convection continuing Nick.

You didn't notice any strange luggage of Paul's did you coz this has all the signs of his storm shield..

I think it will be late in the day if anything kicks off and way past my bedtime..

[NL]

Think ya right there Potty, txt the lads earlier havent had a reply so i reckon they're out on the lash..!!

Was lookin at those storms 80 mile to the south of their last known whereabouts...

[pottyprof]

Possibilities there NL.. Reading Nicks thoughts for tomorrow, they might have headed down that way to be in the right place after following the storms.

Then again, it may be a sightseeing day... Who would blame them??

[NL]

Would'nt blame them at all especially the amount of driving hours Paul has put in!!

Off to the North west of Rapid City in Montana first line of storms producing a fair few meso,s

Edited May 13, 2007 by Northern Light

[Roger J Smith]

Some sporadic non-severe thundershowers developed late today across west central SD but the front located a little further west in eastern MT and northern WY has recently expanded and reached severe limits in several places. This front is producing some large hail and wind gusts to 70 mph. It seems likely to accelerate and move through most of SD overnight, would currently suggest a location in northeast NE or far southeast SD by mid-morning at latest, tonight's position may not matter too much as sleep will be interrupted by loud thunder and lightning with this frontal passage. The dynamics are rapidly becoming more favourable and could become quite violent across eastern NE, se SD, southern MN and western IA tomorrow (meaning Monday, it is still Sunday evening here).

[Paul Sherman]

Hi Guys

Bit of a nightmare of a Chase really, althought the scenery was breathtaking. Hardly got any photos at all, as we chased all the way to near Billings (Montana) and ended up in Gillette (Wyoming) at about 130am Mountain Daylight Time (7 Hours behind now) The highlight of the day was seeing a brief LP Supercell develop at about 7pm and feeling the temperature drop from 85f to 50f in about 20 minutes, we also took on some quarter sized hail of which I will upload video of (Just for Stewart) when the Internet connection is a little stronger. Really tough to chase up here and would have to cross Montana off my list of States to Chase, no roads for 100's of miles and mountainous Pine forests do not make for good chases. Totalled about 650 miles yesterday taking the 3 days since Friday to 1,756.

Will upload the pics i did get in a few days.

Regards

Paul Sherman

[Roger J Smith]

Better get a ten-gallon take-out coffee, hit the interstate and get across SD to eastern NE for today's action, I think the best tornado spot today could be close to Omaha NE, possibly a little north towards Norfolk NE, as well as Sioux City IA.

[Paul Sherman]

Lol,

At least we are Interstate 90 Roger, that should speed things up a bit!

Paul S

[Roger J Smith]

Hey, you're not that far from the Devil's Tower, I got stung by a bee driving along the road out of Gillette on the way in there one fine day in 1984. Hurt like hell for about five minutes, probably led to the brain alterations so evident in later life.

Keep yer windows closed.