Friday, June 29, 2012

Penny is in the water

Penny Palfrey has started her trek for the Keys from Cuba. You may follow her progress using the Penny Palfrey spottracker. She's been in the water a little over an hour and is on a bee line north.
The latest ASCAT satellite image was in a perfect location for a swath across the Florida Straits this morning, winds observed by the satellite pass were 10 knots or less and variable across the entire passage.
The ASCAT observations are supported bu C-Man stations at Sand Key Light (SANF1)
and from Sombrero Key Light (SMKF1)

From National Weather Service WFO Key West Radar (KBYX) and GOES East satellite IR and Visible imagery, we see the only returns this morning from a cloud line along the lower Keys this morning on my SimuAWIPS display.
Conditions are nearly perfect for the swim and I can't wait to congratulate the entire team when they make landfall in the Keys. Go getem' Penny!

Wednesday, June 27, 2012

No more Debby...concentrating on swim weather

The last official statement on TC Debby was issued at issued at 5 pm EDT. So long, farewell.
This issue of the blog will concentrate on the winds and seas across the Florida Straits for Penny Palfrey swim from Cuba to the Keys. The following links are from the GFS and WaveWatch guidance respectively.
10 meter winds, MSLP, and 6 hour precipitation from the GFS guidance
WaveWatch significant wave heights and wind guidance
The Gulf Stream has spread and engulfs most of the straits as seen from the NDDDC Gulf of Mexico Ecoviewer, the wide view then the zoom in.

I spoke with Captains Bob and John this morning about the Thursday start. I have seen satellite altimetry that shows at least 8 to 10 foot seas being refracted around the western tip of Cuba which experience shows would produce a residual swell across at least the western Straits. My thoughts would be to aim for Friday morning as the southerly fetch will allow seas to lay down very quickly. The wind and wave forecast looks great through Monday and is best Saturday and Sunday. A tropical wave is being advertised in the central Atlantic about 1600 miles east of the Windward Islands and doesn't show up in the Caribbean for 6 days.

Tides are important for the swim obviously and the Havana tide table for the 28th, and Key West tide tables and 28th and 29th.

 I wish I could produce better conditions for the swim but this is just about as good as it gets on the Florida Straits. I look forward to greeting you Keys side!

Tuesday, June 26, 2012

Debby makes landfall

And the crowd goes wild!
Debby is forecast to cross the Florida Peninsula tonight and early Wednesday before moving north of the Bahamas Wednesday night and Thursday. The wind field will relax gradually for the Florida West Coast Wednesday and then the East Coast Wednesday night and Thursday. Expect that the Tropical Storm Warnings will be dropped very soon. It will take some time for the flood waters to recede on the Sopchoppy, Suwannee, and St. Mary's (Major flood stage) Rivers  in North Florida, and the  the Anclote (in Major Flood Stage), Alafia, and Manatee Rivers in Central Florida around Tampa Bay. All but the St. Mary's are expected to drop below flood stages by Saturday.
Southeast River Forecast Center

Have to give kudos to the GFS Model Guidance forecast model in that it ended up as the most reliable model for the past week and for Debby. Albeit maybe for the wrong reasons at times but the solution was very good. For this reason I am going with the current forecast for the winds for the next 5 days and the Penny Palfrey Cuba to the Keys swim. Penny-Palfrey Swim on Facebook

The Winds and Seas forecast looks good for Friday and gets better for the duration of the crossing. As does the Gulf Stream.

Go make a successful swim Penny, Chris, Captains Bob, John, and Chris. See you onshore in the Keys!

Monday, June 25, 2012

Debby sits and spins, and Cuba to Key West swim

Debby is nearly stationary sitting just south of Apalachicola FL. Mention of the Penny 
Palfrey swim after discussion of Debby.
The uncertainty in the forecast track is the only thing that remains unchanged.
This is always the problem in slow moving, weak systems. The cyclone is stuck in a 
col region between two large scale anti-cyclones, one over the Tropical Atlantic, and 
the other over the Southern Plains in weak steering flow.

The vorticity is stacked very nicely over the center of the storm with a robust ridge 
above 300 mb which is favorable for tropical system life cycles. The problem is that 
a mid level vort west of the storm last night and provided enough shear, with the trough 
to the north to move the deep convection east out over the Atlantic last night. Still Debby 
lies in an area of the Gulf of Mexico outside the warm waters of the loop current but the 
current is nearby.

Ecosystem viewer courtesy of NOAA Coastal Data Development Center 

The interesting item of the forecast today is that the GFS and the ECMWF have come into agreement with the EC now moving the storm over the western Atlantic. The images
below are the 96 hour forecast for the ECMWF and GFS respectively from the
Experimental forecast Tropical Cyclone Genesis Potential Fields courtesy of
Dr. Robert Hart Florida State University.

The obvious differences being the intensity in which the genesis model does not perform
well. The intensity i sup for grabs and depends on the eventual steering, progression, and
whether Debby taps into the Gulf Stream loop current to strengthen again. The only
certainty with the storm at this point is persistence in the slow movement for the next
several days. Debby may move across Florida and over the Atlantic by 96 hours, or just
drift across the Florida Panhandle and weaken. It is a waiting game. The official authority for hurricane forecasts, watches and warnings is the National
Weather Service, National Hurricane Center, and your local National Weather Service
Weather Forecast Office.
The bad news for Debby is as bad or worse for the Cuba to the Keys swim. Looks like
winds will remain near 20 knots through Wednesday and begin to shift SW and decrease
Wednesday night, which may hold the crossing for Sunluver until Wednesday afternoon.
10 meter winds, MSLP, and precipitation

The winds and seas diminish Thursday night and Friday but the earliest start for the swim
looks like Friday morning due to near 20 knots early Thursday, with seas finally dropping
below 3 to 5 feet late Thursday.
Wave hghts in meters, and wind flags in knots
We wait and hope.

Sunday, June 24, 2012

Tropical Storm Debby

I'm sorry it has been a day since TS Debby was started and this is the first blog I've been able to issue. The storm has been making work very busy in an indirect way, but busy all the same. There may be a lot of conjecture about the track of Debby, don't let this get the better of you, and don't focus on the track! The storm is very broad and has some time to go before it gets its act together fully. 
As one can see from the satellite image above the bulk of the impacts from the storm are on the eastern and northern quadrants of the system. This is the reason the tropical storm watch was expended to include the mouth of the Ochlocknee River which includes St. George Island, FL and Apalachicola Bay to the east, and the mouth of the Pearl River near Morgan City, LA west. 

From radar composite across the eastern Gulf of Mexico we find a wide swath of showers and thunderstorms from the Florida Keys, along the Florida Peninsula, and Florida's Panhandle. 

The storm center as of 7 am was located at 27.5N, 87.0W about 170 miles southeast 
of the mouth of the Mississippi River, and about 195 miles southwest of Apalachicola
Maximum sustained winds are near 60 mph and Debby is drifting northward near 2 mph.
Minimum central pressure is 994 mb, or 29.35 inches of mercury.

The model tracks are a little odd and if you remember early in a life cycle of a storm they,
are usually. The GFS has a trough off the east coast pulling the storm across Florida with
the help of a short wave off the Texas coast. The problems with this solution include the
trough axis is too far east, and the short wave feature, (see below)

helping to pick up the storm. This short wave, the large area near the Texas coast,
has been retrograding southwestward few the day, while weakening. This weak short
wave is also the catalyst for shear over the storm and as evidence by satellite during
the past 12 hours. As this short wave weakens the effects on Debby are minimized.
The storm looks a lot better this morning than it has through the life cycle so far. The
system is consolidating and getting its act together. The model of choice with Debby
has been the ECMWF

Currently the 12z run of the model shows landfall near the mouth of the Mississippi
but this too may be a little premature. Because Debby is not fully developed, has not
picked a motion vector, and its close proximity to the northern Gulf Coast, anyone in
the watch area should already be prepared.
This storm will likely become a minimal category one hurricane before it makes landfall,
and the major factors will be associated with the slow forward speed and include heavy
downpours, flash floods, and possible tornadoes. Several tornadoes were reported and
verified along southwest Florida last night. Mariners should remain in port and if you
haven't already done so, initiate hurricane tie down procedures NOW!

The official authority for hurricane forecasts, watches and warnings is the National Weather Service, National Hurricane Center, and your local National Weather Service Weather Forecast Office. 

Thursday, June 21, 2012

Tropical development in the Gulf?

Conditions are becoming much more favorable for an area of low pressure to develop over the Gulf of Mexico during the next few days. Expect that this development will come from the continuing mesoscale convective system near the Yucatan and western Cuba. Current satellite shows the convective environment over the Yucatan Channel which is invest 96L...
The environment near and around this area is moderately favorable but conditions are becoming more conducive for development. The main factor for the lack of organization at this point is the higher vorticity north of the Yucatan.

850, 700, and 500 mb vorticity. Image from CIMSS
Cooperative Institute for Meteorological Satellite Studies
Space Science and Engineering Center  /  University of Wisconsin-Madison 
The shear over this area is just enough to enhance to potential and the shear tendency is almost ideal vertical development.
Current shear and shear tendency. Image from CIMSS
Cooperative Institute for Meteorological Satellite Studies
Space Science and Engineering Center  /  University of Wisconsin-Madison  
The model forecast are very similar through the initial phase of evolution. Then there is some dichotomy in track with the ECMWF keeping a storm in the Gulf then sliding it slowly westward, while the GFS pulls a much weaker system across the Florida Peninsula then intensifying off the Florida / Georgia coast, by Monday. Will wait for a few good runs to offer much more on the forecast of the system. For the models to perform well there needs to be an actual circulation to place into the runs instead of an artificial vortex. 
Anyone along the Gulf Coast states that has not prepared their hurricane kits should do so now!
The official authority for hurricane forecasts, watches and warnings is the National Weather Service, National Hurricane Center, and your local National Weather Service Weather Forecast Office. 

Tuesday, June 19, 2012

Weather for the Penny Palfrey swim:

Good day all,
The current state of the the ocean atmosphere interaction has east winds near 20 knots which
crosses the Straits of Florida on the long axis. The expectation is that this will build seas and swell.

The good news is that winds will turn southerly Wednesday the 20th. The bad news is that although
winds relax a bit on the 22nd, the forecast is for a weak tropical / pseudo tropical low will is
forecast to cross the northeastern Gulf of Mexico during the afternoon of the 22nd. Winds will 
increase again for the weekend to 15 to 20 knots. This will also increase seas and swell mainly 
over the western Straits from the Seven Mile Bridge westward on the 23rd...then spread 
across the entire Keys Coastal waters on the 24th. The link below is provided to loop the forecast
10 meter winds and precipitation over the Straits:
10 meter winds and precipitation forecast

The next link is the Wave Watch guidance for peak wave height, direction, and periodicity:
Wave Watch guidance...height, direction, and periodicity

There is a final note concerning the confidence in the model output. The short term tonight through
the 22nd is very good, with decent agreement through the weekend. For the 24th through the 27th
the agreement differs and we could see a much weaker system in the western Gulf which would
produce a weaker pressure gradient across the Keys area, resulting in relaxed winds and reduced
seas. We still need another day or day and a half to get a better picture.

The Tropical Weather Outlook is good in that the likelihood that we actually have a tropical system
develop is extremely low. See graphic:

My advice is to go into a short holding pattern for the next several days, which we would have to due to the winds currently hovering around 20 knots. In any case winds will go southerly for a long duration starting Wednesday afternoon, which is the reason for the wide spread rainfall across the area. I should mention
that the vertical profile with respect to moisture is expected to remain saturated with nearly 140 percent of normal...okay...lots of rain. :-)

Call me if you have questions,