Keep an eye to the skies next week in Florida

[Bayfisher]

Major shift in steering currents coming
There is little new to report on 92L, the tropical disturbance now just 200 miles east of the Antigua in the northern Lesser Antilles Islands. Heavy thunderstorm activity remains limited, and dry air surrounding the storm continues to interfere with it. The latest crop of 12Z (8 am EDT) computer model runs are similar to the last set of runs, except the new runs are becoming more definitive about a threat to the Bahamas on Saturday and Sunday, and the east coast of Florida or Florida Keys on Monday. The National Hurricane Center continues to give a medium (20-50% chance) that 92L will be a tropical depression by Friday afternoon. I give a 20% chance that 92L will be a hurricane by Monday. An Air Force and a NOAA Hurricane Hunter aircraft are scheduled to investigate 92L simultaneously Thursday afternoon.

As I discussed in last week's blog on steering currents, the hurricane steering pattern for all of July and the first two weeks of August over the North Atlantic has predominantly acted to recurve hurricanes out to sea. The jet stream has been "stuck" in a standing wave pattern, where it dips southward over the East Coast of the U.S., creating a trough of low pressure capable of recurving tropical storms once they get north of the Caribbean Sea (20� latitude). This pattern is in contrast to the steering pattern that set up in 2004 and 2005, when a ridge of high pressure set got stuck over the Eastern U.S. A ridge in this location does not allow hurricanes to recurve, and the U.S. took a terrific battering those years.

This year's steering pattern is about to make a major shift towards the steering pattern observed in 2004 and 2005. According to recent 500 millibar (mb) upper-air forecasts from the GFS model. and ECMWF model, the trough of low pressure over the U.S. East Coast will be replaced by a ridge of high pressure 7-10 days from now. As a result, the surface Bermuda High will extend far to the west over the Eastern U.S. This pattern will mean that fewer hurricanes will be recurving beginning a week from now, and the threat to the U.S. Gulf Coast will increase. Conversely, the threat to Bermuda and the Northeast U.S. will diminish.

There is no way of telling how long this new steering pattern might stay in place. It could last only a few days, or remain in place for several months.

Dr. Jeff Masters
http://english.wunderground.com/blog/JeffMasters/comment.html?entrynum=1019&tstamp=200808

[jameswilder]

The latest weather update has next week as a very busy "tropical" week with high chances of Florida effected are high...I was tuning into the local ABC channel here in Tampa, Dennis Phillips is usually better than most around here but that's my opinion...stay tuned

Yes, I thought Dennis was a pretty fair weatherman when I lived in the Bay area. It does appear that the tropics have fired off. Very impressive wave having exited the African coast in the past 24 hours. Several weather sites I visit are predicting that a large ridge of high pressure will be setting up off the east coast of the US in the coming week, and that will be a similar situation which we had in 2004/2005 in the hurricane season, which tends to push storms into the Gulf of Mexico depending on where the ridge will set up shop. Hopefully, the ridge will be short term, no way to determine right now, I certainly don't want a repeat of 04/05.
4 years ago today almost nearly to the hour, I was dealing with the damage hurricane Charlie left behind, after making landfall 17 miles from my house.

[jameswilder]

The GFDL model has something right off of Florida East coast in five days. Just hit forward on the link. There is a little wind shear patch around it but if it can clear that it will strengthen.
http://moe.met.fsu.edu/cgi-bin/gfdltc2.cgi?time=2008081312-invest92l&field=Sea+Level+Pressure&hour=Animation

Here are the other models.
http://moe.met.fsu.edu/tcgengifs/

Here is the wind shear.
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.html

Yeah, the models are struggling to grab ahold of 92L right now until a closed center of circulation develops. It's held together pretty well today for all of it's interaction with dry air and Sahara dust. If it becomes a Tropical cyclone, the ultimate path will be determined by the timing of the trough coming across the US at the end of the weekend. If it becomes a tropical system, I'm liking the GFDL model runs, the ECMWF- not so much.

The GFDL model has something right off of Florida East coast in five days. Just hit forward on the link. There is a little wind shear patch around it but if it can clear that it will strengthen.

That is storm number one on the NOAA picture I posted.  Currently going WNW.  If it take the path in your link its starts to move north along the Florida coast.  That sort of path isn't much of a threat to Tampa, and probably not even the east coast.  Once storms turn north they eventually hit the upper gulf stream and get kicked to the east.   Obviously the ridge of high pressure to the east of Florida is the unknown factor right now.  It could push that storm over Florida but personally I am not worried about a storm coming over land to Tampa.

Of course the weathermen will talk about it but really its not worth sweating about, especially for folks on the west coast of Florida.  When a storm moves west to the south of Cuba with a path turning north close to the Yucatan Channel, Tampa needs to be take notice.  

[Bayfisher]

What I thought was strange was the very sharp turn the GFDL model has when it passes Cuba. What is the factor that will cause that? I agree that this doesn't seem like a west coast storm.

What I thought was strange was the very sharp turn the GFDL model has when it passes Cuba. What is the factor that will cause that? I agree that this doesn't seem like a west coast storm.

Projected high pressure to the south, and east, plus the upper level gulf stream.  Most storms move north then sharply east at some point.  That is why the ones that go south of Cuba are so potentially threatening to our area, like Charley.

[jameswilder]

What I thought was strange was the very sharp turn the GFDL model has when it passes Cuba. What is the factor that will cause that? I agree that this doesn't seem like a west coast storm.

The GFDL seems to run the intensity of the storm up to a cat 3 storm. The more intense a storm becomes, the more likely it is to respond to any weakness in the steering currents. A moderate tropical storm or weak hurricane might not respond the weakness as the GFDL is forecasting. Then again, the invest area has to develop first.

[jameswilder]

What I thought was strange was the very sharp turn the GFDL model has when it passes Cuba. What is the factor that will cause that? I agree that this doesn't seem like a west coast storm.

Projected high pressure to the south, and east, plus the upper level gulf stream. Most storms move north then sharply east at some point. That is why the ones that go south of Cuba are so potentially threatening to our area, like Charley.

Upper level Gulf Stream? Do you even know what the Gulf Stream is?

[InlandTaipan]

Yes, I thought Dennis was a pretty fair weatherman when I lived in the Bay area. It does appear that the tropics have fired off. Very impressive wave having exited the African coast in the past 24 hours. Several weather sites I visit are predicting that a large ridge of high pressure will be setting up off the east coast of the US in the coming week, and that will be a similar situation which we had in 2004/2005 in the hurricane season, which tends to push storms into the Gulf of Mexico depending on where the ridge will set up shop. Hopefully, the ridge will be short term, no way to determine right now, I certainly don't want a repeat of 04/05.
4 years ago today almost nearly to the hour, I was dealing with the damage hurricane Charlie left behind, after making landfall 17 miles from my house.

Let's not forget the cold fronts currently running down to the south...yes I said cold fronts, they are driven by the jet stream and that is really sagging further south than normal...I live two blocks from the water and I love Hurricane season.

Upper level Gulf Stream? Do you even know what the Gulf Stream is?

Oops, meant jet stream.  Got diving and the gulf on the brain.

[jameswilder]

Yes, I thought Dennis was a pretty fair weatherman when I lived in the Bay area. It does appear that the tropics have fired off. Very impressive wave having exited the African coast in the past 24 hours. Several weather sites I visit are predicting that a large ridge of high pressure will be setting up off the east coast of the US in the coming week, and that will be a similar situation which we had in 2004/2005 in the hurricane season, which tends to push storms into the Gulf of Mexico depending on where the ridge will set up shop. Hopefully, the ridge will be short term, no way to determine right now, I certainly don't want a repeat of 04/05.
4 years ago today almost nearly to the hour, I was dealing with the damage hurricane Charlie left behind, after making landfall 17 miles from my house.

Let's not forget the cold fronts currently running down to the south...yes I said cold fronts, they are driven by the jet stream and that is really sagging further south than normal...I live two blocks from the water and I love Hurricane season.

Yes, there has been a series of cold fronts making it further south than normal this summer season, there is another one stalled across the northern Gulf right now. Great for the drought conditions in N Florida and Georgia. The last stalled front was the gensis of te tropical system which moved west into Texas last week. Those cut off lows which drift into the Gulf early in the season, (may and June) of late (Oct-Nov) sometimes can spin up into tropical systems, sometimes with 24 hours.

[dbucfan]

JamesWilder, Inland Taipan and even you MJS - nice stuff - in my business I track this stuff - with a lot of expert help - everything that has been offered is true - and accurate - we will see how the upper level patterns and potential waves affect this potential storm.

And MJS - folks said Andrew as going to do just what you described.  And Wilma was stunningly unpredictable in it's path and intensity increase while over the Florida penisula.  The fact is - these events are not predictable - but dangerous.  Caution and info are the two best weapons folks have available to them.

[InlandTaipan]

Love the conversation and will continue to watch the updates...the next 45-60 days are going to be interesting ones that's for sure

[replica]

I certainly don't want a repeat of 04/05.
4 years ago today almost nearly to the hour, I was dealing with the damage hurricane Charlie left behind, after making landfall 17 miles from my house.

I forgot what today was, I lived in Port Charlotte when Charlie came through the harbour. Everyone thought it was going to Tampa (including me). I moved a bit further inland after that mess.

[Bayfisher]

Hurricane Charley was bad.  It had Tampa on the edge. I had to help someone that lives in Punta Gorda a short while after.  I remember driving through neighborhoods where you couldn't see the houses on either side of the street because of the debris piles.  A solemn scene.

92L looks like it is picking up a bit.
http://www.ssd.noaa.gov/goes/flt/t1/loop-wv.html