UW Storm Chasing - Alumni Edition

What up team UW-Madison,

While chasing today in the US is most likely going to involve chasing some sort of QLCS or MCS or something, we will be sending out a chase car to see if we can bag a tornado during the middle afternoon hours before everything goes to H-E-double hockey sticks. I describe some advantages and disadvantages below, and note that this discussion is brief and very casual, so if you want to comment more on it go for it, that's what this blog is all about baby:

Chasing Advantages:

Wisconsin located in the warm sector, near the triple point of the deep low pressure system. An occlusion will develop, with the warm sector branching from the twin cities clockwise to Madison and into Illinois. Warm, moist air will be advected from the Gulf of Mexico region into the upper Midwest, and this along with daytime heating will allow for the breaking up of a very weak (if at all even one) EML and morning cap over eastern Iowa and into south-central Wisconsin and destabilize the atmosphere this afternoon. SBCAPE values will reach 1500-2000 J/kg this afternoon. In terms of shear, the region exhibiting maximum helicity (both 0-1 km and 0-3 km) occurs near the warm front, which will push northward into eastern MN and central WI by 1800-1900 UTC. This, along with strong upper level forcing associated with the approaching upper level trough will allow for development of some respectable convection, and hopefully some discrete cells will fire between the triple point and near the warm front starting ~4 pm local time (2100 UTC).

Also, we'll be in Wisconsin, so the home crowd is on our side (that means wear the red AOS "home" jerseys and khaki shorts or else...)

Chasing Disadvantages:

Well, the shear profile is not the best in terms of chasing tornadoes today. Wind speeds remain southerly throughout the lower and middle troposphere east of the cold front (Illinois, southern Wisconsin, southeastern Iowa, south from Illinois towards the Gulf of Mexico), and bulk shear and helicity values (according to the 1200 UTC NAM and HRRR) are not favorable except near the warm front by I90/I94 during the afternoon hours. Since CAPE values are favorable east of the cold front and within the warm sector near the triple point, my guess is that any storms that fire will become linear and form some sort of squall line (with respect to the upper Midwest). Hence, chances of chasing tornadoes safely and accurately are not too high, except for near the warm front and triple point.

OUR GO ZONE: Tomah, WI. It will be just south of the warm front and south-east of the triple point, and is also near the I90/I94 interchange. If we get there by 1830 UTC (1:30 pm CDT), this will give us plenty of time to check out cumulus fields via satellite data (and our eyeballs) and see where to go from there. HRRR is showing lots of scattered convection and cells starting around 2100 UTC. I'm not trusting the HRRR completely, since it overestimated the strength of this morning's MCS and made the one in central Illinois look more epic than it really was. While are chances at seeing a tornado are very small, this will give us a chance to catch any supercells early on before they either die off or possibly congeal and kill our chasing chances for the evening.

Peace out,

Helicity and friends

P.S. Don't hate, use KolourPaint:

Area Forecast discussion...for Monday June 20

I don't post much...but I thought since I took the time to do this
that it should go on the Tommy HRRRRR page...I really wanted to drop
the phrase "go zone"...but didn't want to sound like I was favoring
severe weather...death...and destruction...

A WEAKENING MCS IS EXPECTED TO BE ONGOING BY 12Z TOMORROW MORNING.
THE EXACT PLACEMENT OF THIS MCS...AND THE OUTFLOW BOUNDARIES IT LEAVES
BEHIND WILL HAVE A LARGE IMPACT THE TIMING AND PLACEMENT OF CONVECTIVE
INITIATION MONDAY AFTERNOON. GUIDANCE SHOWS A SHORTWAVE MOVING ACROSS
THE IA/SD/NE BORDER EARLY MONDAY MORNING...WITH THE BEST H850 THETA_E
ADVECTION ACROSS THE IA/MN BORDER. THESE LINGERING THUNDERSTORMS SHOULD
BE ELEVATED...WITH MINIMAL THREAT FOR SEVERE WEATHER...ALTHOUGH A STRAY
WIND OR HAIL REPORT IS POSSIBLE. HAVE HIGHEST POPS ACROSS THE NORTH
TO REFLECT THE NORTHERN TRACK SUPPORTED IN BY THE QPF PLACEMENT IN
THE 19.12Z GFS..ECMWF..AND NAM. HOWEVER...EXPANDED POPS ACROSS THE
ENTIRE CWA TO ACCOUNT FOR THE CONVECTION THAT IS EXPECTED TO BREAK
OUT ACROSS NEBRASKA SUNDAY EVENING...AND MAY STILL BE AROUND BY THE
START OF THE PERIOD. 
THROUGHOUT THE REST OF THE MORNING HOURS AND INTO EARLY MONDAY
AFTERNOON...THE UPPER LEVEL PV ANOMALY ACROSS THE TX/OK PANHANDLES
SHOULD CONGEAL AN TAKE ON A NEGATIVE TILT AS THE JET STREAK ROUNDS
THE BASE OF THE TROUGH. ANY RESIDUAL CLOUD COVER FROM THE OVERNIGHT
CONVECTION SHOULD QUICKLY DISSIPATE...AND WARM AIR ADVECTION WITH
H700 TEMPS OF 14-16C WILL ESTABLISH A CAP ACROSS CWA. AN ELEVATED
MIXED LAYER FROM 700-500MB...COMBINED WITH AFTERNOON CLEARING SHOULD
ALLOW THE BOUNDARY LAYER TO RAPIDLY DESTABILIZE WITH SBCAPES OF
3000-4000J/KG IN PLACE BY LATE AFTERNOON. THIS CONDITIONAL INSTABILITY
WILL LIKELY BE REALIZED BY LATE AFTERNOON/EARLY EVENING AS THE STRONG
SYNOPTIC FORCING WITH THE HEIGHT FALLS AHEAD OF THE PV ANOMALY WILL
DYNAMICALLY DESTABILIZE THE MID LEVELS AND ERODE THE CAP. GIVEN THE
FAVORABLE THERMODYNAMIC ENVIRONMENT IN PLACE...ATTENTION THEN TURNS
TO THE WIND PROFILE TO DIAGNOSE THE CONVECTIVE MODE. BY MONDAY AFTERNOON
THE AFOREMENTIONED JET STREAK WILL BE SURGING NORTHWARD ACROSS CENTRAL
KS...EASTERN NE. DEEP LAYER SHEAR VALUES OF 50-60KTS WILL SUPPORT
SUPERCELLS. MEANWHILE 6HR PRESSURE FALLS OVER EASTERN NE/SD WILL
RESULT IN SOUTH SOUTHEASTERLY SURFACE WINDS. SOUNDINGS SHOWS VEERING
WIND PROFILE IN THE LOWER LEVELS FAVORABLE FOR TORNADOES GIVEN THAT
THE STORMS WILL BE SURFACE BASED. THE HIGHEST SHR VALUES WILL BE
ALONG THE WARM FRONT...WHICH SHOULD BE LOCATED ACROSS THE NORTHERN
HALF OF IOWA BY LATE AFTERNOON. 
CURRENTLY ENVISION THE SCENARIO UNFOLDING WITH THE WARM FRONT LIFTING
ACROSS THE I80 CORRIDOR BY 18Z...HWY20 BY 21Z...AND TOWARD HWY18 BY 24Z.
GIVEN THE MODEL TRENDS WHICH HAVE INTENSIFIED THE SYSTEM SLIGHTLY AND
SLOWED IT DOWN...DONT SEE THE WARM FRONT SURGING NORTHWARD INTO
MINNESOTA. ALONG THAT SAME LINE OF THOUGHT...FEEL THAT THE CAP WILL
MOST LIKELY HOLD UNTIL AT LEAST 21Z...WITH CONVECTION BREAKING OUT IN
THE AREA OF ENHANCED CONVERGENCE ALONG THE WARM FRONT. THESE STORMS
ARE EXPECTED TO BE SUPERCELLULAR AND COULD QUICKLY TURN SEVERE. MEANWHILE
ANOTHER ROUND OF STORMS SHOULD DEVELOP CLOSER TO THE UPPER LEVEL DYNAMICS
ALONG THE DRY LINE IN EASTERN NE/KS...AND MOVE THROUGH CENTRAL IOWA
OVERNIGHT. THESE STORMS WILL INITIATE AS DISCRETE SUPERCELLS...AND
LIKELY GROW UPSCALE INTO A LINEAR COMPLEX WITH EMBEDDED HP SUPERCELLS.
THE SEVERE THREAT MAY LAST THROUGH THE EARLY MORNING HOURS OF TUESDAY.

- Hailstone...

Few Clips of Chase video from 455

Here is a sneak peak of footage from our chase class, dates and locations are included in the videos...a more comprehensive webpage will be completed in the coming days. 

Watch in 720p!

http://www.youtube.com/watch?v=S3JZmTaUbS8

http://www.youtube.com/watch?v=xjGLOF1lSeQ&feature=related

http://www.youtube.com/watch?v=Jfc47lLzNUc

Convergence

Blame Arizona

I just wanted to warn chasers about swarms of dust floating around from the enormous Arizona wildfires. These swarms have been known to murder developing, tornado-ambitious cumulus clouds in cold vein.

On a side note, the UW storm chasing class team will begin processing footage and pictures this week and we'll have them posted by the end of the week, hopefully.

OCD

Montana here we come!!!

All,

One chase vehicle will be leaving tonight as we head west to chase the Northern Plains...Feel free to add your thoughts and analysis. With one week left in the chase class, we figure this could be our last decent shot at tors (hope not though).

Convergence

Storm Chasing on our Home Turf

Afternoon All,

We are nearly at Eau Claire where we plan to under go an epic exchange, severely increasing the amount of helicity in and around our chase vehicles. From there we plan to hang with the eventual cu field and bag a tor...er...thats the plan for now at least. Looks like two plays for the day, one is way up in NW WI and the other, which I stated above, is to hang with the southern stuff, which is in favorable chase terrain/road network.

Convergence