A few tibits for spring '05

[Rich Thompson]

The following are based on preliminary SPC logs, and some info from forecasters at the Norman and Tulsa NWS offices:

tornadoes in OK this May - ZERO (previous low of 2 in 1988)
tornado deaths in conus April-May - ZERO (last time this happened?)
significant (> F1) tornadoes in conus this May - not many, maybe none

I'll have to check on the lowest May tornado total for the conus since 1950, but the rough log value of 114 has got to be way down there (consider how many of this May's "tornadoes" were just dirt whirlies or less).

Finally, OKC needs 0.21" of rain in the next 36 hours to avoid the driest spring (Mar-May) in the past 116 years.

Rich T.

 

[Ben Prusia]

I remember there being a tornado reported in OK this month on the 24th. Since it was relayed through the Media, some Joe Blow could have called that in, but I am not sure.

2145 8 N SALLISAW SEQUOYAH OK 3558 9479 RELAYED THROUGH MEDIA OF TORNADO SPOTTED NEAR BRUSHY LAKE. (TSA)

Severe Weather Statements that day indicated of spotters reporting a large tornado on the ground.

 

[Mike Peregrine]

Good grief - what a crazy year! ... Thanks for posting that, Rich. Seemed like that single OK tornado report was a matter of debate, Ben. Does anyone know when the last time there were NO tornado deaths like the report mentions? Has it ever even happened?

 

[Aaron Kennedy]

Tulsa NWS negated that tornado. This year has been quite boring... so much for my flexible work schedule! I'm sure next year will be absolutely bezerk. I should be writing up my thesis around that time

Aaron

 

[Rich Thompson]

Some more info regarding May tornado totals since 1953 (courtesy of Harold Brooks, NSSL):

May top 10
2003 556
2004 509
1995 391
1991 336
1982 329
1998 312
1999 311
1965 273
1983 249
1973 246

May bottom 10
1988 132
1987 126
1967 116
(2005 114 through 12z 30 May)
1979 111
1954 106
1966 98
1970 90
1956 79
1963 71
1958 70

Note that warning verification didn't officially start until 1980 in the NWS, and there are roughly 1000-1500+ more chasers now compared to the mid-late 80s.

Rich T.

 

[Shane Adams]

Looks like my generation is finally experiencing the "ashtray" season of our careers. I spoke with a veteran chaser at Wakita who wasted no time in replying to my question "Is this year worse than 1988?"

"Oh yeah."

I'm thanking my lucky stars we've seen what we've seen this year. Relatively speaking, 2005 could end up being as successful as last year for many chasers who were fortunate enough to witness even a single high-contrast tornado event. I've got no complaints.

Thanks for posting the info Rich.

 

[Anthony Silver]

Thanks for posting those stats Rich. I know chasers in Oklahoma (and other parts of the Cntrl/Srn Plains) are going nuts right about now due to the lack of severe weather. I kind of had my doubts about how this year would turn out. I figured since the last two years were extremely active, mother nature would be taking a break this year. That looks to be the case so far. I sure hope June and July makes up for the down time.

 

[Jeff Lawson]

Originally posted by Shane Adams
I'm thanking my lucky stars we've seen what we've seen this year. Relatively speaking, 2005 could end up being as successful as last year for many chasers who were fortunate enough to witness even a single high-contrast tornado event. I've got no complaints.

I feel somewhat thankful that I essentially took the season off for personal reasons (lack of funds, busy searching for a job). Last year was somewhat similar, as I was busy finishing up school. The difference is that last year was very painful (I got out on May 29, at least), whereas, this year, I don't feel like I've missed all that much.

However, it's disappointing nonetheless. I was hoping for some local chase opportunities, at least, especially now that I'm in Nebraska. And, I definitely hate seeing everyone else having a bad year, chase buds in particular. It's gotten to the point that I don't even like discussing the pattern with folks, as everyone else has more invested the season than I do at this point. It's much rougher on them than it is me, and I can't help but feel a bit self-conscious as a result.

 

[Scott Olson]

According to SPC data the only other year where no tornado deaths were recorded for APR-MAY is 1992. .

Tornado Reports 1992:
APR- 53
MAY- 137

1992 then went on to have the most active June in recent history at 399 tornadoes. 1993 also followed a similar pattern with both months having an active July. Not implying this year will be like that but one can certainly hope! I also believe as many do that tornadoes before 1980 are under reported. Interesting that if you remove all the years pre-warning verification that this could be the worst May on record.

Between 1950-1999 there were 19 years were June held the top number of tornadoes. 12 years where April had more recorded tornadoes than May.

1950-2004 NUMBER OF YEARS WITH RANKING TORNADO FREQUENCY:
MAY: 27
JUNE: 20
APRIL: 5
MAR: 2

LONGEST CONSECUTIVE MONTHLY RECORD:

1959-1962 (MAY)

The last three years MAY has taken the record and it appears MAY will not do so this year. Based on rankings from 1950-2004 JUNE is 3X more likely to hold the yearly tornado ranking when May does not. Im sure this number is going to change a bit but we have a current ranking of 347 tornadoes for the JAN-MAY timeframe with a mean average of 385 for the 1950-1999 timeframe. Of course the real average is probably significantly higher. The three year average (2002-2004) for JAN-MAY would yield 611 tornado reports.

-Scott Olson

 

[Sarah Berling]

Originally posted by Anthony Silver
I kind of had my doubts about how this year would turn out. I figured since the last two years were extremely active, mother nature would be taking a break this year. That looks to be the case so far. I sure hope June and July makes up for the down time.

Would the fact that OK is going through a drought have anything to with the unusually slow year? And would the unusually active hurricane season last year have anything to do with this year's drought? I read somewhere that the hurricanes cooled the GoM's temperatures, which would directly affect the amount of moisture that these areas are receiving. Do I have it right?

Sarah

 

[Jeff Lawson]

Originally posted by Sarah Berling
Would the fact that OK is going through a drought have anything to with the unusually slow year? And would the unusually active hurricane season last year have anything to do with this year's drought? I read somewhere that the hurricanes cooled the GoM's temperatures, which would directly affect the amount of moisture that these areas are receiving. Do I have it right?

That approach complicates matters more than necessary, I think. A somewhat persistent blocking pattern that's favored upper-level low pressure over northeast Canada has continually brought cool, Canadian airmasses into the Plains this Spring. In late April, many of these airmasses even overspread the Gulf. So, you have continuous scouring of moisture with each cold front passage, and with sea surface temperatures running a couple degrees lower than normal in the Gulf as is, the return flow isn't all that juicy once it does set up. As for the latter half of May, you had upper level ridging in the Plains, northwest flow aloft, and a low sitting over the Gulf, routing already poor return flow over the southeast United States. So, moisture has been hard to come by so far this season.

Also, even when southwest flow has set up (like earlier in May), it hasn't been particularly strong. There's been a few good days here and there, and they made for some good storms. Of course, with the lack of moisture, high-based storms have been the norm, so tornadoes have been hard to come by. Still, there's been some good structure here and there.

But, obvious lack of tornadoes, several mediocre days, setups getting worse before they get better, a few high-profile cap busts, poor model performance, a week of ridging to cap it off, all on the heels of two very productive seasons - it all makes for a pretty sad May. But, as Shane points out, there have been some good storms, and I know many chasers who are enjoying themselves out there this year, slow season or not. And, of course, June may pay off yet.

 

[Jeff Wear]

May bottom 10

1958 70

Interesting that 1958 is at the bottom of the list. Like 2005, that was also a very active year for tornadoes in CA. Would be interesting to see how similar the upper air pattern that year was to this year.

 

[Rodney Price]

Originally posted by Scott Olson
According to SPC data the only other year where no tornado deaths were recorded for APR-MAY is 1992. .

Tornado Reports 1992:
APR- 53
MAY- 137

1992 then went on to have the most active June in recent history at 399 tornadoes. 1993 also followed a similar pattern with both months having an active July. Not implying this year will be like that but one can certainly hope!

<stuff deleted>
-Scott Olson

Scott, thanks for looking up that information! We were talking about this at work earlier tonight, how relatively quiet April/May 1992 was...then June just took off. We broke out the Significant Tornadoes Update 1992-1995 and noticed (if I recall correctly) an outbreak in OK/TX on May 11, then some other stuff around Sioux City, IA May 16. (Got hailed on pretty good there that day on a chase!)

Then, no entries until June 15, 1992...wow! I've never seen such a monster of a storm as we did in Mitchell County, KS that night.

1993 on the other hand was much more active. The Catoosa, OK tornado on April 24 was a killer. Then May 5 - 9 all were very active tornado days.

Of course, past performance doesn't guarantee future results (sounds like a stock commercial) but we'll see how things go the next few weeks.

Rodney

 

[Anthony Silver]

Would the fact that OK is going through a drought have anything to with the unusually slow year? And would the unusually active hurricane season last year have anything to do with this year's drought? I read somewhere that the hurricanes cooled the GoM's temperatures, which would directly affect the amount of moisture that these areas are receiving. Do I have it right?

I think Jeff's response is a more accurate portrayal of the current weather situation in the Central and Southern Plains. The past several cold fronts had a tendancy to wipe out moisture return from the Gulf, therefore making it difficult, if not impossible for severe weather formation. I cant see how last year's active hurricane season had any bearing on this year's severe weather drought.

 

[Jeff Wear]

Originally posted by Anthony Silver

Would the fact that OK is going through a drought have anything to with the unusually slow year? And would the unusually active hurricane season last year have anything to do with this year's drought? I read somewhere that the hurricanes cooled the GoM's temperatures, which would directly affect the amount of moisture that these areas are receiving. Do I have it right?

I think Jeff's response is a more accurate portrayal of the current weather situation in the Central and Southern Plains. The past several cold fronts had a tendancy to wipe out moisture return from the Gulf, therefore making it difficult, if not impossible for severe weather formation. I cant see how last year's active hurricane season had any bearing on this year's severe weather drought.

The Gulf actually made it through the 2004 season relatively unscathed - Ivan was really the only hurricane that spent much time over the Gulf. I agree that the repeated intrusions of cool air over the Gulf well into the spring have been the main problem impeding moisture return. Also the moisture return trajectories have been bad as well, often coming from the southeastern US instead of deep in the Gulf or the western Caribbean. As for how hurricane seasons affect the following spring's tornado season, it should be pointed out that the Gulf and Caribbean sea were hit just as hard (if not harder) by hurricanes in 1998 (Georges, Mitch) and 2002 (Isidore, Lili) than they were in 2004.