Tuesday, May 29, 2012

Moderate Risk Issued for Tomorrow, May 30

Overall Potential for Severe Weather

Probability of severe weather
There is a 45% chance of severe weather within 25 miles of any point in the northern Oklahoma/south central Kansas areas. 

Thunderstorms should fire along a stationary front connected to a nearby low pressure systen and associated dryline in Texas. The tense clashing of air between the stationary front should result in initiation of showers and storms, likely close to the low pressure system. As the storms form, they will be in the midst of a fair 3000+ j/kg of instability. Hail does appear to be a major threat, with a skew-t from north central Oklahoma identifying up to 1.6 inch hailstones falling.

There will be some potential for tornadoes, but that chance is not high. Eventually, these supercells will converge into one or more clusters and become a more hail/damaging wind threat. I will not rule out the potential for these storms to become derecho formations.



Anonymous said...

How did u figure out the hail size?

Andrew said...

Some skew t images can give expected hail sizes. The WxCaster site is very good with skew-t

Lucas Reynolds said...

Can you also do the wmax equation to find possible hail size?

ERN WX said...

Hello, Andrew. Lapse rates are 8C across my area, CAPE 2500 J/KG, and it is looking serious. I am in 30% hail and wind; and the SPC expects to soon issue a svr tstm watch for my area. A mdt risk in NY/PA. NWS issued a SPS saying that svr storms were probable after 5p. I and every spotter in this area I know have activated and are waiting for the storms. Personally, I am excited, but I worry about others who may not know what to do in case of svr. Any reports I will give you and thanks for everything. When you get the time I would appreciate a post on this threat. thanks

Anonymous said...

I can see this being a derecho or near. I am not home in KS for it though. ERN, have fun but stay safe. Wind events are most dangerous to me; no escaping those shelf clouds. You told me before Skywarn takes awhile. I am finally numbered. I'm also pursuing HAM with some help. Anonymous, it is hard to determine hailsize but not bad determining updrafts if you get SKEW-T basics. I should learn more advanced SKEW-Ts.

Andrew said...

ERN: Thanks for the report in. Much appreciated.

Anonymous: Congratulations on getting numbered!

ERN WX said...

Hello, Anonymous from Kansas. Sorry I haven't been able to reply. Sadly as sun went down the tstms collapsed. Just a little wind and rain. Storms were not fast enough. Congrats on the becoming an official Skywarn spotter!!! It is a great group. SKEW-Ts and lapse rates I use for hail most of the time. Lucas, great to comment with you and others. take care all!!! Andrew, only 1 svr tstm watch so farthis year. Normally 3-5 by now...????? El Nino<