Saturday, July 30, 2011

Asian Trough/Ridge Teleconnection and 91L

I made this comment on facebook/twitter yesterday morning, which lead to many questions:

"91L is something that needs to be watched closely. A legitimate threat for Puerto Rico, Hispaniola, and the Bahamas. From there the SE US/Florida. The Japan/Asian trough/ridge teleconnection holds several clues into the future of what should be Emily."

So instead of me trying to answer everyone on facebook/twitter, I figured I would just write a blog post about the Asian trough/ridge teleconnection and how it relates to 91L's future. I'm going to try to keep this as short and informative as possible.

First, let's look at 3 model output charts from the JMA (12z July 29th run), valid 24, 72, and 144 hours out. You can clearly see Typhoon Muifa, which is bombing out right now! Well on the way to becoming a super typhoon. Here is the forecasted path:

So what do you see? Remember, this is like putting a puzzle together. First you can see that Typhoon Muifa is moving (tropical cyclones propagate, but anyways) in a northerly direction for the most part. This is caused by interaction with a trough, which you can clearly see on the JMA charts. It's not like this trough is very strong/deep, hence the slow movement to the north. If the trough was strong and dug in deep, it would just pick up Typhoon Muifa, pulling it out to sea.

This is not the case though, as Typhoon Muifa will interact with a weak trough for the next several days, before it lifts out and a ridge builds in over the top. Again, make sure you refer to the JMA charts for guidance. This will eventually "push" Typhoon Muifa towards China. Keep all of this in mind as I'll eventually show you how it relates to 91L and the US.

When using the Asian trough/ridge teleconnection you have to keep a few things in mind. First, Tokoyo, Japan correlates to Cape Hatteras, NC (Pretty close to the same latitude). SE China correlates to the Gulf of Mexico. This trough/ridge pattern takes 6-10 days to materialize. Basically, if a trough enters Japan, it should take 6-10 days to get to east coast of the US. The time of year will give you a better handle on whether it's a 6 day telconnection, or a 10 day teleconnection. This is based on wavelengths and is where experience is HUGE! The atmosphere doesn't have a calendar, so each year is unique. As we get later into the summer months, the wavelengths shorten in general. Right now, I would personally say it's around a 7 day correlation, based off experience. I really don't have any guidelines here, as it is really based off feel and experience.

I know some people may laugh at this type of forecasting, but trust me it works! Think of it this way... Say I give you a rope, and told you to stand across a room. If I yanked on the that rope, you will feel the yank (wave) in a certain time period. The harder I yank the rope, the faster/stronger you will feel it. So, the stronger the trough/ridge (this is especially influenced by typhoons like Muifa, as it will amplify troughs/ridges), the faster/stronger the US should "feel" it. Again, this is where experience of watching trough/ridge patterns over and over again comes into play. It's honestly just pure experience. This teleconnection is NOT going to pick up on smaller feature like a subtle shortwave or a cut off low. It works best when major amplification is involved! Also, I can't tell you specific details on what will happen 6-10 days later, but I can at least tell you if parts of the US "should" be under the influence of a trough/ridge. I try to use this all year round with long range forecasting, but I especially like using this teleconnection with the tropics.

With that all in mind, how does this relate to 91L? Ok, I feel confident that 91L will become Emily soon enough, gaining latitude towards Puerto Rico. I think it will be a solid hurricane at this point as well (maybe a major hurricane?). There is a danger this could hit Hispanolia and get torn to pieces. That's very possible! However, let's assume it just misses Hispanolia to the north, and heads towards the Bahamas. This will be a slow process, as Hurricane Emily should be moving slowly at this point. Now comes the million dollar question, does it hit the US, or does it head out to sea?

I'm not going to lie, as this is very difficult to predict. Typhoon Muifa will amplify this trough, so there is a solid chance it could just pick up Emily and take her out to sea, even though it would still be a close call for the US. The other option, is for the trough to lift out, and a ridge to build in over the top, just like with Typhoon Muifa. This is going to be close, as it is all about timing and "guessing" the correct movement of the trough/ridge pattern through amplification. Actually, guessing is probably the wrong word, as I have many clues on my side, but nailing this down to a 24 hour timeframe is very difficult.

My instincts says the trough will just barely get Hurricane Emily, "pulling" her out to sea. It's going to be so darn close though! Honestly, it is very difficult to predict! The trough could easily miss, as a ridge builds in over the top, "pushing" Emily towards the SE US. I'll need another day or two to really have a good feel for it. I'll post my official track forecast Monday. At least though, you now have an understanding of the Asian trough/ridge teleconnection and how it works. Hopefully, this will help enough so you understand what I'm referring to in future posts about the tropics. There are several more details involved, but I think this is a good start. I hope everyone has a great weekend!

*Sunday update 3:22am: Couldn't sleep, so I decided to look at some data. Things are beginning to hint that the trough may not completely grab what will be Emily. If so, this could be a threat for the Carolinas. I still want to watch it for another day or so before I post my track forecast. Like I said above, it's going to be really close! My instincts still lean towards Emily barely going out. I will say, Joe Bastardi made an excellent point about trough splitting which I should have thought about! Trough splits are something we tend to see a decent amount in the overall pattern we are currently in, so that could be a wild card. Let's see how 91L develops Sunday, and I'll be back on here Monday...

Friday, July 29, 2011

TS Don About To Make Landfall

My forecast for TS Don worked out very well as it will make landfall between Brownsville & Corpus Christi, TX close to a 50mph tropical storm. There is always luck involved in forecasting, but I'm proud that I stuck to my guns throughout! Expect landfall around 8-9pm tonight.

TS DON: 50 mph (1004 mb), moving wnw at 16 mph

Thursday, July 28, 2011

Tropical Storm Don

I have NO CHANGES to my forecast. I still like a solid tropical storm (50-60mph) between Brownsville, TX and Corpus Christi, TX. While you never know with tropical cyclones, especially small ones like Don, I just don't see it getting to a hurricane. Feel pretty confident about that!

Tuesday, July 26, 2011

Quick Thoughts on 90L

This is going to be quick, but I feel like 90L will become our 4th named storm of the season, which would be Don. This is a small system, so fluctuations can occur quickly. However, I feel 90L will become a solid (~ 50-60 mph or so) tropical storm before landfall near Brownsville - Corpus Christi, TX on Friday. There is a chance it could become a hurricane, but I'm sticking with a tropical storm until I see something that says otherwise. It will be moving into more favorable upper level wind conditions (Plus, you'll have an upper low backing away into Mexico), so it does need to be watched closely. Hopefully, this will just be good rain maker for south Texas. Many more updates on 90L to come!

*On a side note: Be very careful on relying on models in these situations. There is not even a closed low, and the resolution of the models is simply not good enough to see it. This is especially true with smaller systems like 90L. The key is to understand the pattern, and the model biases, so you can interpret bad model data is a way that can be helpful as a forecaster. That just takes lots of experience!

Monday, July 25, 2011

A Great 4/27/11 Chase Account

Here is a great chase account from Stephan Frank on 4/27/11. Stephan and his chase partner Micahel Brewer was actually in the truck were I have a shot of small debris falling near it. Here soon, I'll release the video so you can see it in more detail. It wasn't like anything huge was falling out of the sky, but still, it was raining debris on us for about 5 minutes. The first tornado you see in Stephan's account is the one we both saw near Macon, MS. We (with Michael Carter) continued NE into Alabama, while Stephan & Michael dropped south. They saw another EF-3 tornado in Sumter County, AL. Stephan got some amazing shots (Michael shot some amazing video), so make sure you check out the chase account. 4/27/11 is a day I'll never forget, and someday soon I'll have a much more detailed chase account with many pictures/videos.

Sunday, July 24, 2011

Be Hurricane Prepared - 4

Here is the fourth video from the "Be Hurricane Prepared" video series. This fourth video is on preparing your mobile phone. Enjoy!

Thursday, July 21, 2011

Hurricane Dora, aka "BUZZSAW"

Hurricane Dora is a "buzzsaw", with maximum sustained winds of 155 mph and a pressure of 929 mb. Only 1 mph away from being a category-5 hurricane. However, Hurricane Dora won't be able to keep it up much longer, as it is heading towards much cooler water. Very beautiful to look at though!

Wednesday, July 20, 2011

Tropical Storm Cindy

Tropical Storm Cindy has formed, but it is a weak 40mph TS. Only a minimal threat to fish in the north Atlantic. Nothing to worry about!

In other other news, check out Hurricane Dora. What a BUZZSAW! 135mph - 948mb

Tuesday, July 19, 2011

Be Hurricane Prepared - 3

Here is the third video in the "Be Hurricane Prepared" video series. This third video is on hurricane preparedness and insurance. Enjoy!

Monday, July 18, 2011

1 km High Resolution

Here is an awesome 1km high resolution satellite image from Tropical Storm Bret near peak intensity this afternoon. It went from trying to form an eye and becoming a hurricane, to falling apart in less than 6 hours. Lol! It just goes to show how fast tropical cyclone intensity can change!

This is how TS Bret looks now. Falling apart fast!

Sunday, July 17, 2011

Tropical Storm Bret

TS Bret has formed! 40mph (1009mb) - moving SSE at 2mph


TD TWO has formed, which just goes to show how useless weather models can be with small/weak systems like this. It just doesn't have the resolution to see it! TD TWO doesn't appear to be a threat to the US, as it should head out to sea. The NHC has it becoming TS Bret by tonight/early morning. Something to watch closely for sure!

Saturday, July 16, 2011

Typhoon Ma-On

Typhoon Ma-On has maximum sustained winds of 125mph, moving at the NW at 10mph. This is gong to cause a lot of problems for Japan, which is the last place on earth that needs this. I just hope everyone is ready and prepared!

Thursday, July 14, 2011

ECMWF Pressure Anomaly Forecast

My friend Todd Ferebee posted this today, and I thought it was pretty darn interesting. The darker the blue, the higher the probability of below average pressures. You can clearly see that the ECMWF (European) is forecasting a huge area of below normal pressure anomalies in the heart of the MDR/Atlantic basin during the main peak of the hurricane season. Of course this is just a forecast, but I personally think things are going to really start picking up fast in about 3 weeks (~ August 4th and beyond). I still feel very strong with my seasonal forecast of lower numbers than last year (~13/14 storms) with much higher impact (which won't be tough to beat). Still really like 1950 & 1955 as the best analog years. This would focus the impact more towards Florida/SE US. I would also throw 2008 in the mix as well (Northern Gulf of Mexico). I really hope everyone is prepared, because it is coming. Please don't wait to the last minute!

*Also, look at the precipitation anomaly forecast as well. Very interesting, which follows the pressure forecast very well. This just gives me more confidence in Euro's forecast!

Wednesday, July 13, 2011

Be Hurricane Prepared - 2

Here is the second video in the "Be Hurricane Prepared" video series. This second video is on generator maintenance and safety. Enjoy!

Tuesday, July 12, 2011

Be Hurricane Prepared

Check out the first video of the "Be Hurricane Prepared" video series. This is the series I worked on with Mark Sudduth from More will be added over the coming days. Enjoy!

Monday, July 11, 2011

Great Gulf Coast Trip!

Sorry I haven't blogged in a week, but I was out with testing our RC plane for upcoming field work. Everything tuned out great, and I'll leave some video below. It was great to be out in the field with Mark & Paul, and I look forward to upcoming hurricane missions with them. I'll have a full write up on our trip later this week, plus I'll post many pictures from across the Gulf Coast. Going back to the places I rode out Katrina, Ike, and Gustav really brought back a lot of memories. I was very encouraged with what I saw overall. Of course many of these places (especially Bolivar Peninsula) has a long ways to go, but I saw lots of positive things! Even got to see the Ninth Ward for the first time. Sobering, but also encouraging at the same time. It's important to remember these events, so hopefully people will leave next time. The time to get prepared is now!

Monday, July 4, 2011

Happy 4th of July!

I hope everyone had a great 4th of July! Can't complain here. Had a nice BBQ with a few good friends, and then went to go see some fireworks. For a small town, I was fairly impressed. Since as long as I can remember, I have always enjoyed the 4th!

In other news, I won't be blogging much over the next week (will still update some on facebook/twitter) because I'll be heading down to the Gulf Coast with Mark Sudduth. We are going to meet up with Paul Bowman to test out the UAV in Galveston/Bolivar Peninsula. This is going to be in amazing tool to have during the hurricane season, and it will be exciting to see the plane in action. We will also have a "meet and greet" at the Outback steak house in Clear Lake, TX (Near the Johnson Space Center) on Thursday evening at 8pm. Please come if you can. For a full write on the trip, check out Mark wrote a much more detailed post on what we will be doing on our trip across the Gulf Coast. Really looking forward to it!

Friday, July 1, 2011

A Couple of TS Arlene Images

This is from Wednesday night around 8pm CT...

Also, here is a pretty cool visible satellite loop I found on youtube of the development/landfall of Tropical Storm Arlene. To see, click here! There is little doubt in my mind that Arlene would have became a hurricane if it had a few more hours over water. It was really wrapping up nicely just before landfall...