Targeting During Enormous Days

[Jared Orr]

My question comes from looking at tomorrow's situation. Large outbreak expected, initially along the dryline if the models verify. However, the expanse of this juicy area is huuuuge.

What are some little cues that forecasters can use to narrow down their target location from an area as large as an entire state to something much more manageable? Because days like tomorrow just seem great everywhere.

I'm especially looking for methods for determining where the cells will be the most unlikely to clump up or line out.

Thanks, folks.

 

[Sanjeev Kirubakaran]

Jared, normally, you want to look for areas that show little or no cap and some type of lifting mechanism such as a dryline. Outflow boundaries left over from morning storms are good focus points out ahead of a dryline,such as in tomorrows setup. Warm front play can be a likely area as well if there isn't continued precip along the warm front throughout the day. In a setup such as tomorrow, almost anywhere east of the dryline and south of the warm front is a good bet since in a synoptic setup like this, long lived discrete supercells are likely. One cell could track over 100+ miles as long as they don't have convective interference from other storms. This gives you the opportunity to position yourself.

Tomorrows setup has potential for development well ahead of the initial dryline development since the warm sector will become very unstable. The stronger the EML, the better chance of high cape values to create strong updrafts to break the cap well ahead of the dryline. I look for high cape, high temp, high dewpoint areas with some type of boundary to create lift.

Hope that helped.

 

[Skip Talbot]

The triple point (intersection of dryline/cold front and warm front) is often a very popular pick on outbreak days if it is well defined. Its often an area of enhanced directional shear and lift, and may have more of an enhanced tornado potential than further down the dryline. The warm is not very sharp tomorrow, but you can kind of think of there being a fuzzy one extending out east from the nose of the dryline bulge in south central KS: http://www.twisterdata.com/data/mod..._221_2011052312_F36_DPTF_2_M_ABOVE_GROUND.png No doubt that will be a popular target tomorrow. If you're worried about discrete modes/interference and the cap isn't too strong, you can try playing further south down the dryline. The shortwave trough looks like its ejecting to the south though, so there may be plenty of storms down the dryline anyway: http://www.twisterdata.com/data/mod.../23/12/NAM_221_2011052312_F36_WSPD_500_MB.png The most discrete/isolated storms will be in Texas probably. Your temp/dewpoint spreads might get pretty bad down there though.

Apart from the forecasting, consider all the non meteorological aspects when targeting on an outbreak day. You've got quite a lot of wiggle room here with lots of storms in a large, favorable environment, so instead of picking a spot with the best parameters, you might want to pick a spot with the best road network and terrain. It can also be very rewarding to play storms outside of the parameter bullseyes. You'll be sharing the storm with fewer chasers and may see something amazing that few others will.