Chase 2010 - Day 32 Discussion

[Nick F]

Looking at the model output from this morning, storms could intitiate in the tri-state area of Wyoming/Montana/South Dakota, with a bullseye of CAPE in this area at 00z (18z) just ahead of a slow moving baroclinic zone running SW-NE which has a low pressure area along it over WY and also a developing low over Wern ND:

- prog charts for 18z (3pm) and 06z (midnight)

- SBCAPE at 00z (18z)

Best wind shear looks to generate initially over SE Montana NE of the low over eastern Wyoming and near/along frontal boundary, then increasing upscale by midnight with increase in S'erly low-level jet. So best severe potential here:

Ideally I would want to target SE Montana for storm initiation, however, looking at google maps - road options look rather poor N and NE in that area ... so I would from a practical point of view look at targetting from NW South Dakota up into SW North Dakota - say Buffalo, SD to Bowman, ND.

Anyway, here the SPC outlook with 5% tornado probs:

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1256 AM CDT FRI MAY 28 2010

VALID 281200Z - 291200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS NRN PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/SRN

APPALACHIANS AND PIEDMONT...

...SYNOPSIS...

UPPER AIR PATTERN WILL REMAIN CHARACTERIZED BY RIDGING FROM MN TO

NRN MEX...AND SPLIT FLOW RELATED TO REX CONFIGURATION OVER WRN NORTH

AMERICA. SRN PORTION OF REX PATTERN CONTAINS LARGE CYCLONIC GYRE

NOW COVERING PAC COAST STATES AND ADJACENT WATERS OF NERN PAC...FCST

TO SHIFT SLOWLY EWD/INLAND THROUGH PERIOD. PRIMARY/EMBEDDED

SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER

NWRN CA -- IS FCST TO MOVE NEWD AND ELONGATE MERIDIONALLY...ITS 500

MB VORTICITY PATTERN STRETCHING FROM SRN GREAT BASIN TO WRN MT BY

END OF PERIOD. AS THIS OCCURS...CONSENSUS OF OPERATIONAL MODELS AND

SREF MEMBERS SUGGESTS CLOSED 500 MB LOW WILL RE-DEVELOP BY 29/12Z

INVOF MT/AB BORDER. MEANWHILE...SHORTWAVE TROUGH NOW ANALYZED INVOF

SRN LM AND ERN IL WILL MOVE SWD TOWARD UPPER MS DELTA REGION AND

INTO PRE-EXISTING HEIGHT WEAKNESS OVER GULF COAST STATES. BY END OF

PERIOD...THIS WILL BECOME ANCHORING PERTURBATION FOR BROADER REGIME

OF MID-UPPER LEVEL TROUGHING FROM NWRN GULF ACROSS MS/AL/GA TO NEAR

BERMUDA.

AT SFC...FRONTAL ZONE NOW EVIDENT FROM N-CENTRAL ND TO E-CENTRAL MT

AND NERN WY -- IS EXPECTED TO REMAIN QUASISTATIONARY THROUGH MUCH OF

TODAY. LOW INITIALLY OVER SERN MT SHOULD MOVE NEWD TO

SWRN/W-CENTRAL ND BY BEGINNING OF PERIOD. THIS LOW SHOULD REMAIN

ACROSS WRN ND BUT WEAKEN TO OPEN FRONTAL-WAVE PERTURBATION AS UPPER

TROUGH APCHS NRN ROCKIES AND ANOTHER/DEEPER LOW DEVELOPS ALONG FRONT

AND CLOSER TO BIGHORN MOUNTAINS. DRYLINE SHOULD EXTEND SEWD THEN

SWD FROM THAT LOW ACROSS ERN WY AND NRN/CENTRAL CO...CLOSE TO ERN

PERIPHERY OF MOUNTAINS/FOOTHILLS. COLD FRONT WILL EXTEND SWWD

ACROSS S-CENTRAL WY AND NWRN/W-CENTRAL CO BY 29/00Z. 12 HOURS

LATER...LOW SHOULD EJECT NEWD TO CENTRAL/S-CENTRAL ND...WITH COLD

FRONT OVER SWRN ND...NEB PANHANDLE...AND CENTRAL CO.

MEANWHILE...PERSISTENT ELY/ONSHORE FLOW SHOULD SHUNT EFFECTIVE

FRONTAL ZONE FARTHER INLAND ACROSS MID-ATLANTIC REGION...VA AND

CAROLINAS.

...NRN PLAINS...

CONDITIONAL BUT POTENTIALLY SIGNIFICANT SVR THREAT IS FCST TODAY

MAINLY ACROSS PORTIONS ERN MT...WRN ND AND NWRN SD. POTENTIAL

EXISTS FOR SUPERCELLS WITH DAMAGING HAIL...STG-SVR GUSTS...AND A FEW

TORNADOES DURING LATE AFTERNOON/EARLY EVENING. SVR THREAT BECOMES

MORE ISOLATED AND EVEN MORE CONDITIONAL WITH SWD EXTENT PAST

LATITUDE OF SFC LOW...WHERE LOW-LEVEL FORCING WILL BE WEAKER AWAY

FROM AREAS OF OROGRAPHIC ASCENT. GREATEST JUXTAPOSITION OF

FAVORABLE PARAMETERS IS FCST INVOF FRONTAL ZONE NE OF SFC

LOW...WHERE BACKED NEAR-SFC WINDS WILL MAXIMIZE LOW-LEVEL AND

DEEP-LAYER SHEAR. MODEL FCST LOW-LEVEL HODOGRAPHS ARE WELL-CURVED

BUT RATHER SMALL DUE TO WEAK BOUNDARY LAYER FLOW MAGNITUDES...AND

MAY BE SOMEWHAT LARGER THAN PROGGED DUE TO ISALLOBARIC FORCING

IMMEDIATELY DOWNSHEAR FROM SFC LOW.

PRIMARY FACTOR PRECLUDING GREATER SVR PROBABILITIES ATTM --

ESPECIALLY FOR HAIL AND OVER SRN PORTIONS OUTLOOK AREA -- IS CONCERN

REGARDING TSTM COVERAGE IN FACE OF WHAT SHOULD BE STG CAPPING FOR

MOST OF AFTERNOON AND PERHAPS INTO EARLY EVENING. THOUGH AFTERNOON

SUPERCELL CANNOT BE RULED OUT...BULK OF CONVECTION SHOULD OCCUR

AFTER 00Z...PERHAPS EVEN AFTER DARK. TSTMS SHOULD GROW UPSCALE

THROUGH LATE EVENING AND MOVE NEWD ACROSS ND. MORE CLUSTERED

ACTIVITY WILL POSE SVR HAIL/WIND THREAT...BUT WITH GRADUALLY MORE

PROBABILITY FOR ELEVATED INFLOW AS FOREGOING BOUNDARY LAYER

DIABATICALLY STABILIZES.

[Nick F]

Hmm looking at the 1230z update, could be a late intiation over NE WY, E MT - maybe not going 'till after dark.

...MT/ND...

WATER VAPOR LOOPS SHOW A STRONG SHORTWAVE TROUGH ROTATING ACROSS

CA/NV THIS MORNING. THIS FEATURE WILL MOVE ACROSS THE GREAT BASIN

AND INTO THE NORTHERN ROCKIES TONIGHT. INCREASING LARGE SCALE

FORCING AHEAD OF THE TROUGH ACROSS PARTS OF MT/WY/WESTERN DAKOTAS

WILL LIKELY LEAD TO THUNDERSTORMS FORMING AFTER DARK NEAR OR JUST

NORTH OF THE SURFACE BOUNDARY ACROSS FAR EASTERN MT/NORTHEASTERN WY.

THESE STORMS WILL DEVELOP NORTHEASTWARD INTO WESTERN ND DURING THE

EVENING. ELEVATED SUPERCELLS CAPABLE VERY LARGE HAIL APPEARS TO BE

THE MAIN THREAT...ALTHOUGH DAMAGING WINDS OR AN ISOLATED TORNADO

CANNOT BE RULED OUT FROM STORMS NEAREST THE BOUNDARY.

[Paul Sherman]

Off for some Sight-Seeing to Mount Rushmore and Picture Opps

Then will see how things pan out wether we Chase further North or Position further South for Last Chase Day

Paul S & Team

[Tom Lynch]

Tough call. Will be keeping an eye out for you all.

Tom

[paul - stormchase]

Heading south now...

[Tom Lynch]

Off for some Sight-Seeing to Mount Rushmore and Picture Opps

Then will see how things pan out wether we Chase further North or Position further South for Last Chase Day

Paul S & Team

Paul

tell your navigator that you are 1061 miles from Dallas.

Tom

[ian cameron]

gulp thanks Tom knocking some of those miles off now will see where we end up looking to be near or in Kansas for the night

[Tom Lynch]

gulp thanks Tom knocking some of those miles off now will see where we end up looking to be near or in Kansas for the night

No probs knew you had a trek but shocked me too. Will keep an eye out for weather opportunities along the way.

Tom

[gpspete]

Hope IAN kept an eye open for the cops see you passed through Keystone

[Tom Lynch]

Hope IAN kept an eye open for the cops see your passed through Keystone

Very quick Pete.

Tom

[ian cameron]

`blimming road works drive me mad having to wait at for a car to lead us down the one lane apparently we can not be trusted to do it by ourselves have been waiting more than ten mins now just want to get south and see if anything can come up over us tonight so today is not a complete right off

[Tom Lynch]

Ian

I have to say there seems to be a sherman shield set up atm .. Everything moving NE is melting away and everything SE is moving SE . It didnt look helpful.

Tom

[gpspete]

Very quick Pete.

Tom

I see Keystone I think Abbot & Costello, Chaplin an Fatty Arbuckle

just checking out GRLevel3 some severe storms around but all hundreds off miles away from the guys nothing rotating in them

[Tom Lynch]

I see Keystone I think Abbot & Costello, Chaplin an Fatty Arbuckle

just checking out GRLevel3 some severe storms around but all hundreds off miles away from the guys nothing rotating in them

We are showing our age Pete Abbot & Costello etc, which I grew up with. However I think the high pressure has taken hold and air sinking , not rising.

Tom

[stevestorms]

Hi all, well its over for us this year 24 days of chasing, I am so tired we have clocked up around 9000 miles, Tom and Paul Ian Pat real sorry things didnt work out at the BIG T we ate so late that everything got messed up, im gona put in a complaint about this mainly that they charged us a 18% service charge that they did not deserve, and they made us wait for ever for our food, anyway glad you have all had a great time and hope to catch up this summer back home.

Signing off from the USA Steve.

[Paul Sherman]

Have a safe flight home mate! See you out here again in 2011! And yes the BBQ Is on at the end of July or start of August

Best

Paul, Tom, Ian, John and Pat!

Paul S

[Paul Sherman]

Some Pics from our Down Day at Mount Rushmore (South Dakota)

Paul S

[MAF]

Blimey mate!! your head is biggest!

looks stunning out there Paul. glad to see and read all is going well this tour

Mick

[MAF]

todays outlook from SPC

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1240 AM CDT SAT MAY 29 2010

VALID 291200Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL-NRN PLAINS...

...SYNOPSIS...

HIGH-AMPLITUDE PATTERN ALOFT WILL CONTINUE OVER CONUS...FEATURING

CLOSED MID-UPPER CYCLONES CENTERED OVER NRN ROCKIES REGION AND MS.

WRN LOW IS EXPECTED TO MOVE NWD ACROSS CANADIAN BORDER BEFORE

30/00Z...WITH VARIABLY TILTED TROUGH CURVING SEWD OVER CENTRAL

MT...WRN WY AND SWRN UT BY THAT TIME. ALONG THAT TROUGH...VORTICITY

LOBE SHOULD MOVE FROM UT AT 29/12Z NNEWD ACROSS WY DURING MID-PERIOD

AND WRN DAKOTAS OVERNIGHT. MEANWHILE...CENTER OF BROAD/WEAK UPPER

LEVEL CYCLONE...NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NRN

MS...IS FCST TO BECOME QUASISTATIONARY OVER MS THROUGH ENTIRE

PERIOD.

AT SFC...CYCLONE NOW ANALYZED INVOF NERN CORNER WY...IS FCST TO MOVE

FROM CENTRAL/SRN ND NEWD TO NWRN MN BY 30/00Z...THEN ACROSS NW ANGLE

AREA OF MN OVERNIGHT. TRAILING COLD FRONT SHOULD MOVE EWD/SEWD TO

NEAR FAR-ABR-VTN LINE BY 30/00Z..SWWD INTO FRONTAL-WAVE LOW IN

AKO-IML AREA. SRN LOW SHOULD WEAKEN THEREAFTER AS VORTICITY LOBE

LIFTS AWAY FROM CENTRAL HIGH PLAINS...AND COLD FRONT PROCEEDS EWD TO

WRN MN...SERN NEB...AND CENTRAL/SWRN KS.

...CENTRAL-NRN PLAINS...

SCATTERED-NUMEROUS TSTMS FCST TO DEVELOP INVOF SFC COLD FRONT.

INITIAL DEVELOPMENT SHOULD BE MORE ISOLATED TO WIDELY SCATTERED IN

MID-LATE AFTERNOON...AS NEAR-FRONTAL SFC HEATING AND FRONTAL FORCING

BEGIN TO OVERCOME INITIALLY STOUT CAPPING BENEATH PERSISTENT

ELEVATED MIXED-LAYER AIR MASS. ACTIVITY IS EXPECTED TO GROW UPSCALE

AND MORE CONCENTRATED FROM LATE AFTERNOON THROUGH EVENING. MAIN

MODES WILL BE MULTICELLULAR/LINEAR...ALTHOUGH TRANSIENT

SUPERCELL/BOWING STRUCTURES MAY DEVELOP WITHIN CONVECTIVE BAND.

DIURNAL HEATING AND SFC DEW POINTS MOSTLY 60S F OVER LOWER

ELEVATIONS WILL SUPPORT MLCAPE 2500-4000 J/KG. AS FRONT ADVANCES

EWD...STRONGEST MID-UPPER LEVEL FLOW...HEIGHT FALLS AND LARGE-SCALE

ASCENT WILL REMAIN TO ITS W...WITH SIGNIFICANT COMPONENT OF MEAN

WIND VECTOR PARALLEL TO LOW-LEVEL FRONTAL ZONE. EXPECT EFFECTIVE

SHEAR MAGNITUDES GENERALLY AOB 30 KT IN ETA-KF AND WRF FCST

SOUNDINGS THAT SAMPLE IMMEDIATE PREFRONTAL ENVIRONMENT.

STRENGTHENING LLJ AFTER DARK WILL SUPPORT PREFERENTIAL MAINTENANCE

OF SRN PORTION OF CONVECTIVE BAND ACROSS PORTIONS NEB/KS...SEVERE

THREAT GRADUALLY DIMINISHING WITH TIME OVERNIGHT.

...SERN CONUS...

SCATTERED TO LOCALLY NUMEROUS TSTMS IN MULTICELLULAR CLUSTERS ARE

EXPECTED TO DEVELOP INVOF SEA BREEZE FRONTS AND NUMEROUS OUTFLOW

BOUNDARIES -- BOTH FROM CONVECTION OF PRIOR DAY AND ADDITIONAL

DEVELOPMENT TODAY. SUBTLE LARGE-SCALE LIFT/COOLING ALOFT MAY AID

CONVECTIVE ENVIRONMENT OVER DEEP S. WEAK DEEP-LAYER FLOW/SHEAR WILL

LIMIT OVERALL ORGANIZATION/DURATION OF INDIVIDUAL CONVECTIVE

CLUSTERS...WITH SVR POTENTIAL FOCUSED PRIMARILY ON MESOBETA AND

SMALLER SCALE FOCI. AREA OF MRGL WIND/HAIL POTENTIAL IS QUITE

WIDESPREAD. THREAT SHOULD DIMINISH AFTER DARK AS COMBINATION OF

DIABATIC COOLING AND SPREADING OUTFLOWS LEADS TO UNSUPPORTIVE AMOUNT

OF STABILIZATION.

...NERN CONUS...MID-ATLANTIC TO PORTIONS NEW ENGLAND...

SFC COLD FRONT IS FCST TO MOVE SEWD ACROSS THIS REGION DURING

AFTERNOON/EARLY EVENING HOURS...POSSIBLY PRECEDED BY SFC CONFLUENCE

LINE. ALTHOUGH LAPSE RATES ALOFT ARE FCST TO BE MRGL...SFC HEATING

AND RESIDUAL BOUNDARY-LAYER MOISTURE AHEAD OF FRONT WILL WEAKEN CINH

AND SUPPORT 300-800 J/KG MLCAPE. A FEW RESULTING TSTMS MAY PRODUCE

MRGL SVR HAIL...OR DAMAGING GUSTS. ALTHOUGH LOW-LEVEL WINDS AND

SPEED SHEAR FROM SFC-500 MB EACH WILL BE WEAK...CONSIDERABLE VEERING

OF FLOW WITH HEIGHT AND STG ANVIL-LEVEL STORM-RELATIVE WINDS MAY

BENEFIT CONVECTIVE ORGANIZATION.

[Tom Lynch]

Nice photos Paul. Hope you have a good trip home Steve. I have to say that in all my years of going to the B/Texan that had to be the slowest service ever. Just to add to it I had a drink knocked over me and had to go and change.

Hope to see you at the BBQ and I am sure you will have a good dvd highlights. I will give you a call when I know you are home.

Paul and team , have a safe trip down south.

Tom

[gpspete]

Best

Paul, Tom, Ian, John and Pat!

Paul S

[Devon-Nelly]

Gosh i can't believe im flying out to the states tommorow.

I've been reading the reports and the photos so far from all the tours and they look increadible, there has been so many storms over there, i must admit i've never watched the weather as closely as this in the states before but is there normally this many storms each spring? It truly fancinating.

So I've got my cameras at the ready lol, though it first time with a video camera.

[MAF]

Gosh i can't believe im flying out to the states tommorow.

I've been reading the reports and the photos so far from all the tours and they look increadible, there has been so many storms over there, i must admit i've never watched the weather as closely as this in the states before but is there normally this many storms each spring? It truly fancinating.

So I've got my cameras at the ready lol, though it first time with a video camera.

am sure you will capture some good video, unless Paul S is jumping around with excitememtn in front of you that is

hope you have a great tour and have some happy hunting

have a safe journey tomorrow

[gpspete]

Nice photos Paul. Hope you have a good trip home Steve. I have to say that in all my years of going to the B/Texan that had to be the slowest service ever. Just to add to it I had a drink knocked over me and had to go and change.

Hope to see you at the BBQ and I am sure you will have a good dvd highlights. I will give you a call when I know you are home.

Paul and team , have a safe trip down south.

Tom

Hi Tom and all

i think our order was forgoten about as we didnt all get what we ordered it was so late coming to table after everyone who had ordered after our table had theres i think we had whatever was left and they was able to get out quick as it was getting close to closing time.

regards Pete

[Tom Lynch]

Hi Tom and all

i think our order was forgoten about as we didnt all get what we ordered it was so late coming to table after everyone who had ordered after our tablehad theres i think we had whatever was left and the was able to get out quick as it was getting close to closing time.

regards Pete

I think that is correct pete and I would like to say it is the only time I have had bad service there.

Tom