Thoughts on activity for 2010?

[Jason Harris]

Local NWS at Melbourne has a pdf for download entitled: "Increased Chance of Above Normal rainfall & severe weather this winter and early spring."

THE TOP TWO DEADLIEST TORNADO
OUTBREAKS IN FLORIDA OCCURRED DURING EL NINO EVENTS. THE FIRST OCCURRED DURING THE
STRONGEST EL NINO TO IMPACT THE AREA IN 1997 TO 1998 WHERE SEVERAL EF3 TORNADOES
...WITH WINDS UP TO 165 MPH...MOVED ACROSS CENTRAL FLORIDA DURING THE NIGHT OF
FEBRUARY 22 TO 23...KILLING 42 PEOPLE MAINLY IN THE KISSIMMEE AREA. THE SECOND
OUTBREAK OCCURRED DURING THE MOST RECENT AND MUCH WEAKER EL NINO TO IMPACT THE REGION
IN 2006 TO 2007. DURING THIS EVENT ON THE EARLY MORNING HOURS OF FEBRUARY 2 2007
...TWO EF3 TORNADOES...WITH WINDS UP TO 165 MPH...PUSHED THROUGH SUMTER...LAKE...AND
VOLUSIA COUNTIES KILLING 21 PEOPLE.

http://www.srh.noaa.gov/mlb/
See also:
http://www.srh.noaa.gov/mlb/enso/mlbnino.html
Of note is that the last El Ninos had EF-3 tornadoes for FL.

 

[Jeff Hawkins]

Welp, I'm about as scientific on this thought, as saying that the yin/yang effect will play out, and 2010 will be more active than 2009. However 2010 may NOT be more active, and 2009 will at a minimum be equal to 2010. Regardless, I would say the chances are that 2010 won't be worse than 2009.
For a first year chaser like me, 2009 was perhaps the WORST year one could start in (and I would have had no way of knowing that). However, as a learning environment, the lack of tor's did allow me to focus on the basics of examining visuals, using radar, and maps/GPS. Overall, for this newbie, it was a good year in this way, and I hope 2010 will be more active, yet still a learning environment.

 

[Paul Knightley]

You can tell the winter is on its way when folks start speculating about the season this early! FWIW seasonal forecasting has a very low skill score, so whatever might be indicated is just, essentially, guesswork!

 

[Drew.Gardonia]

Some interesting facts.

When I was in the military in 2002, I was stationed at Ft. Eustis, VA (close to Norfolk and Newport News) for AIT. We were under a Hurricane Watch for a Hurricane (I believer it was Hurricane Kyle that passed a 100-150 miles east of us, but I remember it dumped a crap load of rain in Oct or Nov for days on end, and barely missed us).

Anyhow, that following spring when I was out of the military and back home in KC was one of the worst years for tornadoes in the KC Metro Area, as my dad's work in Riverside, MO was decimated by a true F4 (not EF4) on Sunday May 4, 2003 of which one of the largest outbreaks for tornadoes (401 Reported) occurred over a week long period (May 3 - May 11) extended over 19 States, and 1 Canadian Province.

http://en.wikipedia.org/wiki/May_2003_tornado_outbreak_sequence

You can see pictures here of what a True F4 does to a commercial trucking company.
http://viewmorepics.myspace.com/ind...iewPicture&friendID=460593069&albumId=1034440

So this late Hurricane in the Gulf right now, is very promising for what's in store to come next year.

EDIT: Interesting tidbit of info....2002 was an El-Nino year, just as 2009 is!!!!!!

http://archives.cnn.com/2002/WEATHER.../el.nino.2002/

I know weather trends are never "identical" but weather patterns do tend to repeat themselves, so I think one would be fairly safe to say we could some pretty severe outbreaks in spring 2010.

I hope it's as busy as 2003 was, because that was one helluva year. I hope it's in the same time range (May 3 - 31st) which would be ideal for me because I'll be out of school till June 1st.

 

[Drew.Gardonia]

21 days into the New Year (and January for that matter) and we've already had some very powerful thunderstorms here in Middle Tennessee last night and today.

The lightning incredible, and the thunder was just ear popping. I haven't thunder like that in a long long time.

Today there were some tornado warnings in Middle Tennessee as well, unfortunately I was under the hood of a car all day and was unable to chase.

I think it's going to be very active this year!!!

 

[Jason Boggs]

I've been trying to find a good source on the web, but I haven't found anything reliable that goes back to 1995, so here goes: What was the precip. situation like during the winter of 1994-95? I would suspect that there was a pretty decent amount of moisture present to allow storms to occur deep into the Texas panhandle, as they did that year (i.e. Friona, Dimmitt, Dougherty, Pampa x2, etc.).

Of course, I'm no expert in the field, but I think there may be 2 possibilities for those storms to occur so far in the western TX panhandle (Friona and Dimmitt).

There very well may have been a good fetch of deep moisture from a LLJ the night before which brought a rich, deep supply of moisture from the gulf up through the panhandle. Of course the deeper the moisture supply, the slower it will advance eastward during the day.

Also, there may have been good moisture content in the ground and vegetation (evaportanspiration) which helped hold the dryline further west than it normally would have if the soil was dry.

Bottom line is this. Some may not fully believe this, but evapotranspiration or lack thereof makes a big difference when it comes to determining where the dryline will setup when maximum daytime heating occurs.

Hope this all makes sense.

 

[Paul Knightley]

I swear these "coming season's activity" posts get earlier and earlier! Without wishing to be a kill-joy, it's just too early to make any sensible prediction of activity. However, not being sensible I took a look at the ECMWF seasonal forecast which has just come out. It suggests ridging across the eastern states, with a below average 500mb gph towards CA. It also hints at wetter than average conditions through the central Plains...now, the skill of this kind of longer range prediction is, on average, very low...but I can't help but look!

 

[Rocky Rascovich]

Hey Paul, Where is the link to this forecast?

 

[Chris Hayes]

One thing that I dont think has been mentioned is the drought situation across the western US. Every week I look at the drought monitor when the new map comes out on thursdays. The map released today has to show the best drought situation for the country that I have ever seen. With the exception of Hawaii, there is no extreme drought. There are patches of severe drought across the west, but NOTHING like we've been seeing for years now. Hopefully the situation will continue to improve. In theory, the lack of huge areas of drought could prevent, or at least make it hard for a death ridge to form. And again, there is little to no drought across the plains.

http://www.drought.unl.edu/dm/monitor.html drought map

 

[Richard Dickson]

Chris,

I found your analysis and graphic to be very interesting. I simply can't remember the source, but within the past week I saw a chart (NOAA I believe) that showed most of southern Arizona and southern California predicted to be above average precipitation from now through the first part of April. We are thankful for anything we can get as southern Arizona has been in a drought pattern for greater than ten years.

I will openly display my ignorance, but I don't think I understand how the dry west helps to cause the death ridge over the Great Plains. Not having a degree in meteorology, I sometimes struggle to fully comprehend local events, let alone something on the global scale. I'd appreciate anything you could offer to clear this up. A PM is fine if you don't want to get into it on the forum.

Thanks,

 

[Chris Hayes]

Chris,

I found your analysis and graphic to be very interesting. I simply can't remember the source, but within the past week I saw a chart (NOAA I believe) that showed most of southern Arizona and southern California predicted to be above average precipitation from now through the first part of April. We are thankful for anything we can get as southern Arizona has been in a drought pattern for greater than ten years.

I will openly display my ignorance, but I don't think I understand how the dry west helps to cause the death ridge over the Great Plains. Not having a degree in meteorology, I sometimes struggle to fully comprehend local events, let alone something on the global scale. I'd appreciate anything you could offer to clear this up. A PM is fine if you don't want to get into it on the forum.

Thanks,

I dont have a meteorology degree either, so dont worry. When we refer to death ridges we're talking about large ridge forming over the western US, not the plains. During the 10 days of May in 2003, a trough of low pressure was PARKED over the western US sending out waves that triggered the outbreaks. When you have drought conditions, it allows the air to be drier. The drier the air, the warmer it can get. The more moist the air is, the harder it is for it to get really warm or hot. Ridges in the northern hemisphere allow for it to get warmer where they set up shop. In theory, because there is so little drought, as compared to the past years, a death ridge should have a harder time setting up shop. If the drought situation over the western US continues to improve so dramatically it will be harder for it to get so hot, making it harder for a ridge to form. Now this isnt all over. Inevitibley a ridge will form over the desert SW. Hopefully it wont form over the entire west till well into June, allowing us plenty of time to chase. Hope that was understandable

 

[Rich Thompson]

The big problem with the drought - ridge relationship is which comes first? The same can be said for return flow moisture and Gulf of Mexico temperatures. Is the moisture return marginal because of the cool water temperatures, or is it simply a reflection of the same unfavorable large scale pattern that produced the cool water temperatures in the first place?

The southwest is seeing reductions in rainfall deficits because of an active southern stream jet and multiple storm systems every 1-2 weeks. If this same flow regime persists through the spring, it won't get dry as fast as usual across the southern Rockies. However, this same pattern often results in cool and wet conditions across the southern Plains into April, which is not ideal for early season chasing.

The long-term drought/flood periods are largely controlled by planetary scale flow and not local feedbacks. Otherwise, how would you ever get out of a drought? In a similar vein, you often hear talk of the dryline position with respect to soil moisture (i.e., it will be farther west this year because the southern Plains are "wet"). Again, it's a chicken and egg problem. It's wet because of the weather pattern, and that same weather pattern does not favor lots of downslope flow and drying across the southern high Plains. There's really no way to clearly separate the two influences, and it's possible that soil moisture is more a result of the pattern, and not a primary driving force.

 

[MatthewCarman]

The CDC does have "improvement likely" for the main drought areas in the west except the north west and if we keep getting storms like this the severe drought areas in the south west should dissapear.

 

[Richard Dickson]

Thanks for the followup with my question. I was hurrying to get it typed before my wife and I had to leave to drive to Phoenix this morning. About halfway there, I had one of the 'forehead slap' moments and instantly knew the answer to that one. Oh well, what can I say?

I can also see the point that Rich is making about the relationship between the drought and the ridge and I look forward to watching the outcome of this in the next few months.

 

[Paul Knightley]

Hey Paul, Where is the link to this forecast?

Hi Rocky,

I'm afraid it's not a publicly-accessible part of the ECMWF site.