What is your favorite boundary to chase?

[Jarrod Cook]

I voted Warm Fronts. This is because around Illinois, thats usually how we get our small tornado outbreaks. Drylines don't usually come this far east.

 

[Mike Johnston]

Sounds like cold fronts kind of have a bad name (maybe for scouring out the atmosphere in their wake and delaying the next setup?), but in reality cold fronts are a factor in many spring setups, especially in places like central and eastern KS. A pre-frontal trough, especially one that is negatively tilted, and/or wind shift line ahead of these central plains cold fronts usually holds good promise in the early and mid spring. W/ good insolation at the surface, and a tongue of cold air advancing on the western horizon - well, it's exciting to just think about!

 

[nickgrillo]

A few of my better days during the past year or two:

6/13/04: Central/Northern MI... This day had a cold front situated across eastern WI, with a warm front stetching back to the east across central/northern MI. An isolated supercell exploded to the north of Grand Rapids, and quickly became a prolific tornadic supercell that persisted for about 5 hours. Obviously, I have a warm front to thank for that day.

6/9/05: Northwest KS... This was probably one of my coolest days ever chasing. This day had dryline situated from extreme southwest NE then southward into the TX panhandle. In northwest KS, a outflow boundary intersected the dryline near Hill City. Deep moist convection initiated along the extreme northern end of the dryline across southwest NE and into northwest KS, and quickly moved away from the boundary and died. To the south, a supercell exploded right on the OFB/DL intersection... And this would become one of the most famous supercells of the year. Supercells also formed south on the dryline, as well, from southwest KS into the TX panhandle -- also producing some tornadoes. This was a dryline/OFB day.

6/12/05: Northwest TX... This was probably the best chasing day of the year, and probably my chasing so far. This was another dryline/OFB day... Cells continued to pop along the boundaries all afternoon, one becoming a SVR-warned supercell and then quickly dying. Then, by mid-afternoon... More convection initiated... In the form of a cluster - but the storms quickly organized into two incredible supercells. The northern one was the first to go TOR-warned, but didn't look worth my time... So I headed south towards the southern (well, middle one) supercell and by the time we all got there (chased with Kurt H, JR Hehnly and Dan Robinson that day) it produced the first tornado - and another half dozen or so followed.

5/12/05: Northwest TX... Believe it or not, I actually have a cold front to thank! A cold front plowed through the TX panhandle during the afternoon, initiating a long-lived supercell that formed in the Plainview area. By the time we got south towards the now developing supercellular complex, all tornado warnings was withdrawn. Then, we got to the storm near South Plains... And it immediately dropped a beautiful white cone (then barrell) tornado. Then, it followed with a large wedge and a brief trunk. We were lucky to find ourselves with windshields after we chased that storm.

5/13/05: Northwest TX (lol, I am so biased now)... A large group of chasers (including myself, Kurt H, Amos M, Jason M, Tony L and about a dozen others) woke up in the day's target! Talk about a treat... A dryline/cold front/OFB intersection was in place at 18z... And a pronounced mesolow was over northern Floyd county. The OFB became more diffuse and lifted northward into the Childress area. This would be combined with a very moist and unstable boundary layer... With a SFC moist axis containing 60-65 Td's and sbCAPE was a respectable 2500 j/kg. Well formed Tcu persisted across the Childress area, which we had the pleasure to watch from a resteraunt parking lot there in Childress. A storm just to the south of Childress exploded, and about 2 scans later, it was SVR-warned and was showing supercellular traits. This day pretty much was thanks to the OFB and dryline.

In the upper midwest, I am pretty biased towards warm fronts and OFBs. In the plains, I am pretty biased towards drylines and OFBs... Particularly in the TX panhandle.

 

[Andrew Khan]

I love to chase drylines, and sometimes, perhaps an OFB. I usually go for drylines, since that is where the majority of severe weather can occur, especially tornadoes. OFB's are tricky, because they can dissipate fairly quickly. Cold fronts are fun too, but not as near, to drylines.

Wait a second, Andrew.......you have chased before? Or is this what you want to chase? Sorry if I recall incorrectly......

I have never chased Drylines before. I have chased a small OFB once, and cold front, here in EAST TN both before. I look forward to chasing a dryline, however. It WOULD be my favorite boundary to chase, though.

 

[Mike Hollingshead]

Hmmm I don't see my pick as an option. I think Kurt has it right. Outflow boundaries intersecting a dryline/sfc trough seem to be the best. Or you could just call it a double point, which is not an option either. Give me a double point or triple point over a dryline alone anyday. May 4 and 8 2003 this did not pay off too well however. Other than that pretty much anything cool I have seen was on a double point or triple point.

 

[Angie Norris]

I voted dryline but I'd much rather try to get on the triple point just to have the dynamics working for me. I've not chased enough warm fronts yet to have an opinion there, but outflow boundaries usually work pretty well.
Back in TN, you didn't really have a choice...99.9% of the time, cold front. Drylines don't make it that far east, warm fronts were almost always way north...like Ohio, and didn't see too many OFBs. When I finally got out here, it was like "wait...too many choices..." :wink:
Angie

 

[Andrew Khan]

Yes, Angie! Pretty much all I've seen this past spring are, Cold Front mostly, and one or two OFB's.....not many options, I Know.

 

[Gabe Garfield]

I prefer outflow boundaries only because it narrows the potential target areas down much better (not to mention the locally enhanced shear and lowered LCL heights). I've been burned too often on the "any storm on the dryline has an equal shot at producing a significant tornado" idea only to come up with nothing. Either that, or the storm to my north or south produces the significant tornadoes of the day! LOL

Gabe

 

[Patrick Kerrin]

Hmmm I don't see my pick as an option. I think Kurt has it right. Outflow boundaries intersecting a dryline/sfc trough seem to be the best. Or you could just call it a double point, which is not an option either. Give me a double point or triple point over a dryline alone anyday. May 4 and 8 2003 this did not pay off too well however. Other than that pretty much anything cool I have seen was on a double point or triple point.

I agree with Mike and generally really like the sfc backing associated with Triple-points.

Beyond that I have to consider each situation based on its own merit - every situation is different - that is why we forecast and not just apply a cookie-cutter paradigm to a chase day. There are so many variables at play and to consider (e.g. Is there sufficient CAPE along/beyond a given W Front? What will the orientation of UA flow do in terms of seeding adjacent cells along the DL? What outflow boudaries remain, and maybe even more importantly what LL horizontal vorticity might remain along old outflow boundaries that have lost their thermal gradient and radar/satellite signature? etc.)

Beyond that I can state that I generally do not like chasing Cold Fronts or situations with unidirectional shear (so common up here).

 

[Michael P. Morris]

All in all I prefer drylines, simply because they have been the most productive for my career (yeah all 2 but whatever). My least favorite is WF's as the line between boom and bust is too faint for my tastes.