Chase 2010 - Day 36 Discussion

[Nick F]

Quite a large SLIGHT risk today over the central/northern Plains – though best tornado potential looks to be over S and E Nebraska, Iowa, and far N of Kansas. A quick look at NAM suggests ongoing convection likely during the day across central Nebraska and Nern Kansas with an MCS, but perhaps chance for more discrete storms further east in moistening warm sector towards Iowa.

Looking at NAM wind shear and CAPE charts, I would target somewhere in SE Nebraska such as Beatrice or Falls City to perhaps get on some more discrete storms – some decent CAPE values as moist air advects into this area later and wind shear increasing too. Storm motions should at least be slow enough for chasers to keep on storms.

SPC 1230z update for today:

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0729 AM CDT TUE JUN 01 2010

VALID 011300Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO

THE MID/UPPER MS VALLEY...

...UPPER MS VALLEY INTO WESTERN GREAT LAKES...

RELATIVELY FAST ZONAL FLOW IS PRESENT TODAY ACROSS THE

CENTRAL/NORTHERN UNITED STATES...WITH SEVERAL EMBEDDED LOW-AMPLITUDE

SHORTWAVE TROUGHS. ONE STRONG SYSTEM IS NOTED ON WATER VAPOR

IMAGERY OVER MANITOBA/NORTHWEST ONTARIO WITH 12Z RAOBS/MODELS

SHOWING AN ASSOCIATED 50-70 KNOT WESTERLY MID LEVEL JET ALONG THE

US/CANADIAN BORDER. THE RIGHT-ENTRANCE REGION OF THIS JET WILL MOVE

ACROSS THE UPPER MS VALLEY TODAY...WHILE ANOTHER MORE SUBTLE

SHORTWAVE TROUGH APPROACHES THE REGION FROM THE WEST. THESE

FEATURES WILL INCREASE LARGE SCALE FORCING FOR UPWARD MOTION AND

LEAD TO MULTIPLE BANDS/CLUSTERS OF INTENSE THUNDERSTORMS THIS

AFTERNOON AND EVENING ACROSS PARTS OF MN/IA/NEB/KS/MO.

STORMS ONGOING OVER SOUTHERN NEB MAY WEAKEN THIS LATER MORNING

BEFORE RE-INTENSIFYING WITH THE HEAT OF THE DAY ACROSS IA/MO AS

MLCAPE VALUES EXCEED 2000 J/KG. OTHER STORMS ARE EXPECTED TO

INITIATE ALONG THE SURFACE COLD FRONT OVER SOUTHEAST SD/SOUTHERN MN

AND SPREAD SOUTHEASTWARD INTO IA/WI. BOTH OF THESE AREAS WILL

LIKELY SEE SUPERCELL STORM STRUCTURES CAPABLE OF VERY LARGE HAIL AND

ISOLATED TORNADOES. AN EVENTUAL TREND OF UPSCALE ORGANIZATION INTO

A FAST-MOVING MCS IS POSSIBLE TONIGHT AS STORMS SPREAD ACROSS IL

INTO IND...WITH DAMAGING WINDS BECOMING MORE LIKELY.

...KS/NEB...

ANOTHER FAST-MOVING SHORTWAVE TROUGH CURRENTLY OVER UT WILL CROSS

THE CENTRAL ROCKIES AND BEGIN AFFECTING THE HIGH PLAINS BY LATE

AFTERNOON AND EARLY EVENING. EASTERLY/NORTHEASTERLY LOW LEVEL WINDS

ALONG AND NORTH OF THE SURFACE BOUNDARY OVER NORTHERN KS WILL

TRANSPORT RICH LOW LEVEL MOISTURE WESTWARD WITH DEWPOINTS IN THE MID

60S OVER MUCH OF SOUTHERN NEB. ISOLATED THUNDERSTORM DEVELOPMENT IS

EXPECTED ALONG THE OLD FRONT FROM THE NEB PANHANDLE INTO SOUTHEAST

NEB. THOSE STORMS THAT FORM WILL LIKELY BE SUPERCELLS WITH THE RISK

OF LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES.

...NORTHEAST AND MID ATLANTIC STATES...

MORNING SURFACE ANALYSIS SHOWS A COLD FRONT MOVING EASTWARD ACROSS

PA/NY. SCATTERED THUNDERSTORMS ARE EXPECTED TO FORM ALONG/AHEAD OF

THE FRONT AND SPREAD EASTWARD ACROSS SOUTHERN NEW ENGLAND THROUGH

THE AFTERNOON. MORE ISOLATED STORMS WILL ALSO BE POSSIBLE FARTHER

SOUTH INTO THE MID ATLANTIC STATES THROUGH THE LATE AFTERNOON. DEEP

LAYER VERTICAL SHEAR SUGGESTS A FEW STORMS MAY BECOME ORGANIZED WITH

THE RISK OF LOCALLY DAMAGING WINDS AND HAIL. AREAL COVERAGE OF

SEVERE STORMS IS CURRENTLY EXPECTED TO BE RATHER SPARSE...THUS HAVE

MAINTAINED ONLY LOW SEVERE PROBABILITIES.

..HART/GRAMS.. 06/01/2010

[nsrobins]

Well RUC pulls a rabbit out of the hat and this one is fast becoming a decent play.

Crazy CAPE and loss of inhibition around the 22Z mark (NAM) should see initiation along the old boundary with rapid transition to supercells I would think.

This is a watch and wait set-up as far as the detailed location goes but I would sit on an axis Marysville, KS to Wymore, NE and see what happens.

[TornadoJo]

2nd time lucky?

Gut says far North Eastern Kansas borders.

J x

[nsrobins]

The shortwave currently scooting towards Montana provides the trigger for the target area, along with any outflow from the complex currently rumbling away in eastern NE. I've been peering at WV imagery in an atempt to see the disturbance but can't as yet identify it.

What are the current obs in the field?

[Paul Sherman]

Starting In Liberal and heading up towards the I-70 - Then Eastwards towards Salina and onto Concordia for starters, a good 5-6 hours drive, but liking the Concordia to Fairbury to Hiawatha Area for some Slow Moving Supercells today.

Paul S & Team

[nsrobins]

Fair call Paul. The initiation target depends as usual on a number of factors, the largest IMO being depletion of inhibition and timing of shortwave impulse.

I think this will occur further west than the far NE corner of KS and is the reason I'm thinking more far N C KS or just east of there.

You have a hell of a jaunt to get up there but the good news is you can use the Liberal to Pratt and then North to Great Bend roads which are pretty straight and fast from memory - also it looks like a late afternoon show just now so five hours should be enough.

[Nick F]

SPC 1630z update gone MODERATE RISK, with 10% tornado probs over SE Nebraska and SW Iowa, includes hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. :

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1119 AM CDT TUE JUN 01 2010

VALID 011630Z - 021200Z

...THERE IS A MDT RISK OF SVR TSTMS MUCH OF ERN NE/WRN IA AND PARTS

OF NWRN MO AND SERN SD...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO

THE MID/UPPER MS VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF SOUTHERN NEW

ENGLAND...

...CENTRAL PLAINS INTO MID MS VALLEY...

FAST ZONAL FLOW WITH EMBEDDED S/WV TROUGHS EXTENDS FROM PAC NW TO

NERN U.S. IMPULSE MOVING EWD ACROSS WY/NRN CO THIS AFTERNOON WILL

DEEPEN LEE TROUGH/SFC LOW CENTRAL HIGH PLAINS FURTHER ENHANCING THE

SHEAR PROFILES THIS AFTERNOON IN AN ALREADY FAVORABLE ENVIRONMENT

FOR SEVERE THUNDERSTORMS.

ELEVATED SEVERE THUNDERSTORMS DEVELOPED THIS MORNING AS A VERY

UNSTABLE AIR MASS SPREAD NWD OVERNIGHT ACROSS THE CENTRAL PLAINS.

WITH MID LEVEL LAPSE RATES NEAR 8C/KM AND MLCAPES AOA 3000

J/KG...ALONG WITH 30-40 KT OF SHEAR...LARGE HAIL IS ALREADY A THREAT

ALONG AND AHEAD OF THE COLD FRONT SAGGING SEWD FROM CENTRAL MN WSWWD

TO WRN NEB.

DAYTIME HEATING COUPLED WITH THE EXPECTED INCREASE IN THE LOW LEVEL

JET RESPONDING TO DEEPENING LEE LOW CENTRAL PLAINS...PARAMETERS WILL

BECOME FAVORABLE FOR SURFACE BASED SUPERCELLS BY MID AFTERNOON

ACROSS MUCH OF ERN NEB AND INTO WRN IA. AS LOW LEVEL WINDS BACK

ACROSS ERN NEB IN RESPONSE TO PRESSURE FALLS TO THE W...POTENTIAL

FOR TORNADO'S ALONG WITH VERY LARGE HAIL WILL INCREASE BY MID/LATE

AFTERNOON ACROSS ERN NEB...AND INTO WRN IA/NWRN MO BY THIS EVENING.

HAVE UPGRADED TO A MDT MUCH OF ERN NEB/WRN IA FOR THE RISK OF VERY

LARGE HAIL GIVEN THE EXPECTED EXTREME INSTABILITY. BY EVENING SHEAR

PROFILES BECOME INCREASING FAVORABLE FOR TORNADIC SUPERCELLS SERN

NEB/SWRN IA WITH POSSIBLY A STRONG TORNADO.

STORMS EXPECTED TO DEVELOP UPSCALE INTO ONE OR MORE FORWARD

PROPAGATING MCS/S EARLY TONIGHT MOVING EWD ACROSS MID MS VALLEY WITH

AN INCREASING CONCERN FOR DAMAGING WINDS.

...SRN NEW ENGLAND...

THUNDERSTORMS ARE BEGINNING TO INTENSIFY ACROSS SE NY ALONG AN AXIS

OF MODERATE INSTABILITY WHERE OBJECTIVE ANALYSIS SHOWS SBCAPE VALUES

IN THE 1500 TO 2000 J/KG RANGE. THIS MODERATE INSTABILITY EXTENDS

EWD ACROSS MOST OF SRN NEW ENGLAND WHERE SFC DEWPOINTS ARE IN THE

MID 60S F. INCREASING LARGE-SCALE ASCENT ASSOCIATED WITH A SUBTLE

SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY SHOULD RESULT IN A

GRADUAL EXPANSION OF CONVECTIVE COVERAGE. THE BOSTON WSR-88D VWP

ESTIMATES 40 KT OF FLOW AT 1 TO 2 KM AGL WHICH COMBINED WITH

INCREASING INSTABILITY AND STEEPENING LOW-LEVEL LAPSE RATES THIS

AFTERNOON SHOULD RESULT IN AN ISOLATED WIND DAMAGE THREAT. HAIL WILL

ALSO BE POSSIBLE ESPECIALLY IF A SUPERCELL CAN ORGANIZE ACROSS THE

ERN PART OF SRN NEW ENGLAND WHERE VERTICAL SHEAR IS STRONGER THAN

AREAS TO THE WEST.

ANY SEVERE THREAT THAT DEVELOPS SHOULD QUICKLY MOVE OFFSHORE BY

EVENING.

..HALES/JIRAK.. 06/01/2010

[kold weather]

Yeah that sounds good to me as well, the current stuff that has been over KS is starting to clear away hopefully allowed some good heating during the afternoon hours to occur.

Certainly is a long way to go, I was just looking at the map and its a good 4-5hr trip from the looks of things, still conditions aloft are decent and once the CINH is reduced things will go boom as nsrobins said.

Now the build up to the hurricane season is over (for now!) I've got more time to watch these events again.

ps, given the way the models have somewhat upgraded on the 12z run, moderate risk seems justified.

[Nick F]

MD issued for likely watch across Ern Neb, Sern Minnesota and Iowa:

MESOSCALE DISCUSSION 0762

NWS STORM PREDICTION CENTER NORMAN OK

0143 PM CDT TUE JUN 01 2010

AREAS AFFECTED...NRN/CNTRL IA...SRN MN

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 011843Z - 011930Z

CORRECTED FOR AREA AFFECTED/WORDING 1ST PARAGRAPH

AN ISOLATED THREAT FOR LARGE HAIL AND WIND DAMAGE SHOULD DEVELOP

ENEWD ACROSS NRN/CNTRL IA AND FAR SRN MN THIS AFTERNOON. IN NW IA

AND ERN NEB...A TORNADO THREAT MAY ALSO DEVELOP. BECAUSE OF

THIS...WW 240 WILL NEED TO BE REPLACED WITH A TORNADO WATCH.

A BROKEN LINE OF STRONG THUNDERSTORMS IS ONGOING FROM SRN MN WSWWD

TO JUST NORTH OF SIOUX CITY ALONG A GRADIENT OF MODERATE TO STRONG

INSTABILITY WHERE MLCAPE VALUES ARE ESTIMATED IN THE 1500 TO 3000

J/KG RANGE. SFC DEWPOINTS ALONG THIS GRADIENT IN NW IA HAVE RISEN

QUICKLY INTO THE LOWER 60S F AND SHOULD CONTINUE TO INCREASE INTO

THE UPPER 60S F THIS AFTERNOON. IN ADDITION TO THE VERY UNSTABLE

AIRMASS...THE SIOUX FALLS WSR-88D VWP CURRENTLY SHOWS ABOUT 40 KT OF

0-6 KM SHEAR WHICH ALONG WITH STEEP MID-LEVEL LAPSE RATES SHOULD

EASILY SUPPORT SUPERCELLS WITH LARGE HAIL. THE MORE DOMINANT

SUPERCELL STORMS MAY PRODUCE VERY LARGE HAIL AND POSSIBLY A TORNADO

OR TWO. THE TORNADO THREAT SHOULD EXPAND SWWD WITH TIME AS NEW CELLS

INITIATE IN ERN NEB LATE THIS AFTERNOON. THE SEVERE THREAT MAY ALSO

DEVELOP SEWD ACROSS CNTRL IA WHERE THE STRONGEST INSTABILITY IS

LOCATED. FURTHER NORTHEAST ACROSS SE MN...A HAIL THREAT SHOULD ALSO

DEVELOP AS SFC DEWPOINTS INCREASE AND THE AIRMASS BECOMES MODERATE

UNSTABLE.

..BROYLES.. 06/01/2010

[Nick F]

Tornado watched issued an hour ago for Nebraska and Iowa:

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 241

NWS STORM PREDICTION CENTER NORMAN OK

155 PM CDT TUE JUN 1 2010

THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

MUCH OF WESTERN IOWA

LARGE PART OF CENTRAL AND EASTERN NEBRASKA

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 155 PM UNTIL

1000 PM CDT.

TORNADOES...HAIL TO 4 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE

MILES EITHER SIDE OF A LINE FROM 35 MILES EAST SOUTHEAST OF FORT

DODGE IOWA TO 55 MILES SOUTHWEST OF BROKEN BOW 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 240...

DISCUSSION...ONGOING SEVERE THUNDERSTORMS NRN NEB AND NWRN IA WILL

BECOME MORE WIDESPREAD THRU THE AFTERNOON AS VERY UNSTABLE AIR MASS

FEEDS NWD THRU THE WATCH. SHEAR PROFILES ALREADY FAVORABLE FOR

SUPERCELLS INCLUDING VERY LARGE HAIL AND TORNADO THREAT. WITH LOW

LEVEL JET INCREASING TO 35-40KT ERN NEB/WRN IA TOWARD

00Z...POTENTIAL WILL INCREASE FOR TORNADOES INCLUDING POSSIBLY A

STRONG TORNADO IN ADDITION TO VERY LARGE DAMAGING HAIL AS STORMS

CONTINUE TO DEVELOP S AND E ACROSS THE WATCH AREA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

600. MEAN STORM MOTION VECTOR 25030.

...HALES

[nsrobins]

RUC holds the cap in the eastern target area until 22Z and then drops it out rapidly in the face of the impulse from the west. Absolutely maniac EHIs of 10.00+ on the NE/IA/KS corner area. I might be starting to re-position now a tad further North of the KS/NE border - say Beatrice, NE.

Initiation in this region should be kicking-off in the next 80 minutes.

[Nick F]

Shame the livestream is down, haven't a clue where the team are?

Nice satellite image over Nebraska showing line of storms from Broken Bow in central Nebraska ENE into Iowa forming on an outflow boundary and another line of storms to the north near frontal boundary. Cu field over south-central Nebraska and clear skies to east over SE Nebraska will be interesting to watch over next hour or so:

[nsrobins]

The impressive cell up near Norfolk, NE has couplet relative motion right down to the base. Not too severe but rotating.

[Nick F]

Does look impressive the storm SE of Norfolk, currently tornado warned too.

It's moving SE, so bit of a deviant mover to the mean E/NE storm motion, so storm will create strong SR Helicity in its environment which will be highly conducive for a tornado to form.

[nsrobins]

Probably understandable that the flotilla is shifting North to intercept it, Nick, but I still think initiation closer to the border is imminent.

[MAF]

Shame the livestream is down, haven't a clue where the team are?

Nice satellite image over Nebraska showing line of storms from Broken Bow in central Nebraska ENE into Iowa forming on an outflow boundary and another line of storms to the north near frontal boundary. Cu field over south-central Nebraska and clear skies to east over SE Nebraska will be interesting to watch over next hour or so:

yeah it was bad enough missing out on last nights chase, but tonight too? i will be going cold turkey at this rate Nick

[Nick F]

Probably understandable that the flotilla is shifting North to intercept it, Nick, but I still think initiation closer to the border is imminent.

Yes, that outflow boundary continues to shift further south across Ern Nebraska and may help break the cap across SE Nebraska in next hour or so.

[gpspete]

noaa weather radio omaha ne saying tornado on the ground trained storm spotters sighted tornado on the ground 3 miles sw craig 38 miles nw omaha

[dogs32]

where is the team?

no stream tonight

I think Paul might take a detour around Nebraska :lol:

The cops and the couplets are not friendly there

[nsrobins]

Daniel Shaw on the complex near David City. Gustnado outflow and plenty of clutter in that lot now.

[Nick F]

Daniel Shaw on the complex near David City. Gustnado outflow and plenty of clutter in that lot now.

Funnel reaching towards ground on his livestream now:

http://www.severestudios.com/cgi-bin/player.pl?username=daniel.shaw&uid=509

Gone now ...

[Paul Sherman]

Well we should have known better - Moderate Risk in Nebraska could only mean one thing and thats what we got.........Naff All, crap structure, a few Lightning bolts and loads of miles on the clock, cant wait to head back into Kansas tomorrow.

RIP Nebraska 2010 - For some reason you really hate me LOL

Paul S & Team

[dogs32]

:lol: ..Hopefully I will love Nebraska next year.....

A true dump at the moment.....

Maybe next year it will be different....

What a mind blowing year for Storms.....who needs UK Storms when you can see the awesome structure out there...

good luck for your next chase day.

just to let you know its like October here...with a dull damp foggy cold start

with Cape of about 100 and Vils around -100

[Paul Sherman]

Lol

Just checked in over on Stormtrack and even the guys further east got nowt

Posts 1 - 7 read..............BUST BUST BUST

Nebraska Sucks this year thats for sure!

Even sampled a lovely LP Supercell today in Kansas near Phillipsburg that just did not want to go over the border, cant say I blame it Hahaha

Paul S

[MAF]

perhaps the Sheffield Shield goes to Nebraska for its holiday this time of year

lets hope things go better for the remainder of the tour Paul :lol: