Hello Dolly

A funny thing happened over the weekend - well, maybe not so funny.  The easterly wave that I talked about in a previous Blog, shown to the right, was moving west but not showing signs of developing.  Our research partners decided they wanted to study this wave to look at its characteristics and see if there was any hope for it to develop.  Known as the Genesis Module, this experiment has multiple patterns that examine the storm at various stages of its life cycle.  The first of these, which was the one planned for our first mission, is a zig-zag pattern at mid-

(about 14,000 ft.).  When a circulation begins to develop in a wave, it normally does it at altitude and then works its way to the surface.  Hence the value of such a pattern.  The orientation is along the axis of the wave and its position is where the wave was forecast to be at the time of the flight.

Well, Dolly continued to develop from that point, taking on the characteristic tropical storm look as shown to the left.  We have continued to fly Dolly every 12 hours since Sunday, and as we approach the wee hours of Wednesday morning, the last of six consecutive flights is on the way back to our home base.  The tracks into the storm have taken on a different look over the evolution of Dolly as shown to the left below.  They are designed to acquire the best tail doppler radar set possible as explained in an earlier blog.  Dolly finally strengthened to a weak Cat 1 storm this afternoon and does not appear to be getting much stronger.  That's a blessing for those along the south coast of Texas and in Mexico.  They'll get plenty of rain but not such high winds.

It's been an exhausting week for everyone, particularly because of the flight schedule.  You are either on the 4:00 am or the 4:00 pm crew, and you start your day (night) at 1:00 am or 1:00 pm.  Either way you travel from night into day or vice versa.  After three, nine hour flights on this schedule the crew members are pretty well drained and, in some cases, down right testy.  But, this too shall pass as we await the next storm where we will repeat the process.  In the meantime, we have a few maintenance issues that we must deal with on the P-3s.  They take a beating flying through those storms, and after three pounding flights into Dolly, they need some tender, loving care.  

During the six flight P-3 evolution, our high-altitude jet, the G-IV, was also quite busy flying the dropsonde missions to obtain profile data to improve the track forecasts.  It flew two 

 and one nighttime mission on Dolly, and as you can see by the figure here that the track of that aircraft covered a lot of area during its eight hours in the air.  Each point on the track is the location of a dropsonde launch.  This was the first flight in the sequence, and the subsequent two flights covered the Gulf of Mexico exclusively.  

With the return of the last P-3 flight at 1:00 am this morning we are through with Dolly.  As you recall from the previous blog, the disturbance that we had planned to fly from St. Croix and was written off as nothing more than a tropical wave finally encountered conditions that were favorable for its development into a hurricane.  It appears that this time Mother Nature outsmarted the best forecasters.  That's why we study these storms - to improve our ability to more accurately predict such events.

In case you missed Dolly's landfall into Texas, the image to the left is from the Brownsville National Weather Service radar.  Nice looking storm.

Two pics of the aircraft involved in the Dolly missions - below is the Gulfstream G-IV preparing for one of its daytime missions with a P-3 in the background awaiting one of its evening missions.  Above are the two P-3s together on the ramp at MacDill Air Force Base (our home), one having just returned and the other preparing for its evening flight.  

The last picture in this posting shows the two pilots on the G-IV doing their pre-flight

before the mission.

Please click on any of these images to see an enlarged version of them.  Hit the back button of your browser to return to the blog.

AL97 sits near the Cape Verde Islands, but at this time the models indicate that it will be turning north into the central Atlantic in the next few days and not be a factor for the Islands or the U.S.  As this is the case, the author of this blog is taking a week off and heading for Wisconsin to a small town on the bay north of Green Bay.  I'll resume this blog when action in the Atlantic picks up once again.

No Go this Time

For once my forecast was right.  The planned deployment to St. Croix scheduled for this morning was canceled.  All parties agreed that the system was too weak and too close to the South American coastline to be of any value.  Looking at this satellite image, I think you will agree.

So, we standby to fly another day.

Blog Reading Suggestions

Some of you may be first time readers of my summer blog, so I thought I would explain the layout and how to get the best out of it.  First, let me say that his is the first blog I've ever done, and I'm still learning the technique in preparing each posting.  For instance, in my early postings I did not know how to embed pictures so that when you click on them they enlarge to almost full screen viewing.  Now, I've learned a few tricks, and like the picture at the right, you can click on it and it will enlarge.  That, incidentally, is a figure from the National Hurricane Center's website showing disturbed areas in the Atlantic basin and their probabilities of development as of 2:00 am this morning, 17 July.  Go ahead.  Click on it.  To return to the blog, simply hit the back button on your browser.

I have a total of 11 postings so far, the earliest being in May and this being the latest.  I encourage you to go back to the earlier blogs, oldest being on the bottom, to get a flavor of what we do here at the Aircraft Operations Center during the hurricane season.  To get to the earlier blogs, simply scroll down or go to the right pane and click on one of the months so see the blogs for that month.  If you click on "2008," you'll get all 11 of them from the latest at the top to the earliest at the bottom.

Hope you find this interesting and informative.

Is This the One?

We've been asking ourselves this question.  Is this the one?  Many of us who have been around think not since this system is so close to the S. American coast and because there is a good bit of shear in the atmosphere - that means winds at high altitudes that rip the tops on the growing thunderstorms and inhibit any development.  But, heck.  We've been wrong before.   

The two satellite images above were acquired today (click on them and use your back button to return to the blog).  The one to the left is a visible picture which is what you would see if you were in the Space Shuttle hurtling around the earth.  The second, to the right, is an IR (infrared) or thermal image which shows the cloud top temperatures - the more colorful, the colder and thus the higher the clouds.  As you can see, most of the "convection" - rapidly growing cumulonimbus clouds - are just to the west of the apparent center of circulation.  There really isn't much there, and that's one of the reasons many of us feel that this disturbance will not intensify into a tropical storm.  But, as my wife says, I'm no forecaster.

  

Well, we are scheduled to deploy to St. Croix in the Virgin Islands (that's to the east and a little south of Puerto Rico) to start flying into whatever is there beginning Friday afternoon at 4:00 pm with the first of our two WP-3D Lockheed Orions, returning at about 2:00 am, with the second P-3 leaving a 4:00 am Saturday morning and returning at 2:00 pm Saturday afternoon.  Crummy hours in my book, particularly since I have to see each aircraft off and meet it when it returns.  We may repeat this sequence two or three times, and after bouncing around the sky for about 10 hours a day, three days in a row, the crew is pretty well done in.  Even though we are on a lovely Caribbean island, there's not much enjoyment to be had.

The above shows the latest forecast track, taking the "storm" across the southern Caribbean.  We'll see how this changes tomorrow morning and whether the storm is forecast to intensify.  We'll have a final decision early in the morning as to whether we head SE to St. Croix or wait to fly another day.

That's enough for tonight.  Still have to pack, and I have an early morning (3:30) get up - go ahead and shed a tear or two to see one of the aircraft off to Jacksonville for some minor maintenance that has to be done at the Naval Air Station there.  If we go, I'll have much more to tell you in the coming days.  For now, Good Night.

Is this the Next Storm in the Atlantic

Bertha is gone - so it would seem.  Is what you see to the right - the bright spot near 9N and 40W - our next storm?  If so, its name will be Cristobal.  Please note that names alternate between English and Spanish, the following being Dolly followed by Eduoard.  Again, you can click on the pics to enlarge them.

The next diagram to the right shows the model forecasts made
this afternoon at 2:00 p.m.  Please notice that there are two distinct sets of tracks, one taking the storm into South America, and the other taking it to the WNW to the northern part of the islands.  The latter set of tracks are from the more reliable models which hurricane specialists tend to rely on more heavily.  We'll have to watch the development of this system over the next couple of days, and I shall get back to you on its likely path.

And So It Begins

And so it began.  The first true Atlantic storm of the 2008 season grew from a wave that emerged off of the east coast of Africa.  Bertha, by name, was a surprise to all of us as it grew from a tropical wave into a Category 3 storm.  There were two dilemmas that faced forecasters as they wrestled with a hurricane that formed  so early in the season in the eastern Atlantic. 

First, there was the rapid intensification of Bertha to Cat 3 - a fact that none of the forecasters predicted.  The second dilemma had to do with the track forecast.  These highly trained professionals rely to a large extent on computer model predictions as shown below for Bertha.  From that, they generate the "official" track shown to the right.  Earlier model runs showed Bertha curving to the north, but as time progressed, they continued to carry it in a more westerly direction, which began to get the attention of the public.

You can see from the picture of the model forecast tracks that there is some large disagreement among the dozen or so different models.  Why such a large difference?  Each model uses different parameters and different math to produce the tracks.  Hence, the difference in the outcome.  The forecasters usually rely on one or two models that they feel provides better guidance and then generate their own official track forecast.  Once again, it can be seen in the figure above and as the black line buried in among the model runs shown above.  (By the way, you may click on any of these figures to get an expanded look.  To go back to the blog, just hit your browser back button.)

Today, 11 July, BErtha is still with us as a weak Cat 1 storm located east of Bermuda.  It does not pose a threat to the U.S. mainland at this time but probably will have some impact on the island of Bermuda.  An interesting fact about Bertha is that it formed in the eastern Atlantic so early in the season.  Normally this does not occur until mid to late August.  The last time this happened was 2005, and we can all remember what occurred that year.  This is not a prediction, - just a fact to keep in mind.