Thursday, September 22, 2005

1 comment:

The preparation stage is coming to an end, and the survival stage is about to begin. From this point on, the storyline changes from a meteorological one to an unfolding massive human drama of unbelieveable porportions. A traffic backup for a hundred miles or more in stifling heat. People from Texas heading north or east thinking they are moving out of the storms path are encountering heavy traffic coming west from Louisiana as those residents flee the same storm since the path appears to be shifted. These drivers may be running out of gas, slowing down efforts to get out in time. So what we thought might be a heroic to save lives by getting people we hope will not turn into a deathtrap. Instead of people trapped in homes with rising water, will we instead see motorists stuck on roads in the storm's path with no fuel and nowhere to hide facing the exactly the fury they were trying to avoid.

I have other points to make in tonight's discussion, including:
1. How a weakening trend will lead to an expansion of the wind field, affecting a larger area.
2. How the inland flooding risk may be greater for areas not in the Hurricane Warning.
3. Will there be another eyewall replacement cycle before landfall?
4. A summary of damage expected by NWS statements posted today

Please check back later this evening.

Saturday, September 17, 2005

or triple...if we get a TD 19 in the far eastern Atlantic soon

Double Trouble 1

All eyes are turning toward two or three developing systems spread across the Atlantic, Computer models are projecting a general west or northwest track in the near-term for these storms, but it is entirely possible that by early next week, we could have Phillipe and Rita. It is also possible that one or both of them will impact either Florida, the East Coast or the Gulf within a 10 day period. The only sticky point is whether or not an upper level trough in the central Atlantic will pickup these systems and recurve them. Some forecasters, including Accuweather, believe the southern system has a low enough latitude that it may avoid interaction with this trough, and allow it to continue on a west-northwest track into the Caribbean this week, and possibly into the Gulf after that. The other possibility is that either system develops, heads north, and is later driven back toward the east coast as the ridge moving in behind Ophelia becomes the dominant air mass over the northeast U.S.

The more interesting issue of the day is that given we will cross the P and R names before September is out, it looks likely the 2005 storm list may run out of names before the season expires. I just learned this is the earliest ever that we will use the R-name, as the last known occurance since 1953 was in October 1995 with Roxanne. Then what? CNN reports that since 1953, when storm naming began, there has not been a situation in the Atlantic basin where the name list was exhausted. The plan is that once we cross the W name (Wilma), the hurricane center will begin using Greek letters, starting with Alpha, then Beta, and so on.


With light shear and very warm SST's ahead, Phillipe is expected to reach major hurricane status within a 5-7 day period. The northerly trend shown here is plausible due to influence of the upper-level trough in the central Atlantic left in the wake of Ophelia. However, there is concern that the high pressure ridge building in the northeast may cause Phillipe to turn back toward the U.S. at the end of this forecast period... in the 120+ hour time frame. The other possibility, that is equally plausible, is the cold front in the Midwest moving east eventually nudges Phillipe a bit more to the east, sending it merrily into the Atlantic, missing even Bermuda. It sounds like a copout to say this, but either scenario has an equal chance until we see which region of the atmosphere begins to exert an influence on steering currents for this storm.

Phillipe 3


Let me be the first to say that within 5 days I believe we will see TWO Category 3 hurricanes in the Atlantic Basin occuring at the same time... Phillipe heading north to northwest, and Rita heading west into the Gulf, both as major hurricanes. There is considerable concern at the hurricane center regarding the track and intensity of this storm, according to a NHC conference call report on Sunday morning. Apparently hurricane watches may soon be posted for parts of southern Florida and the Keys. You can see the reasons for concern below, as the cyclone is soon to cross into waters near 90 F, and in a relatively low shear environment. The GFDL, which is sometimes right on (as it was for most of Katrina's projected path) and sometimes way off (as it was for Ophelia) has a Cat 4 or 5 heading west-northwest towards the Texas coast. Wouldn't it be a crying shame if those who evacuated to Houston have to evacuate AGAIN? Given the warm Gulf, and no major weather systems to influence Rita's path or strength, I see this storm easily reaching Cat 3 and by the end of the week, may be churning toward the Texas/Mexico coast as a Cat 5.

Rita 1

More on this developing tropical forecasting overload once we get TD named as Rita.


Ophelia 5

My apologies to our friends in southeast New England and the Canadian maritime provinces for not posting earlier on the fact that you were going to be sharing in Ophelia's dance. While the tropical storm warnings were a good idea and put the public on alert, it is encouraging to see that at least ONE geographical area of the U.S. was spared from a direct hit. However this is not the case for eastern coastal Canada, as Nova Scotia is now in the cross hairs, and will feel the full brunt of this expiring storm. While this will not be nearly as bad as Hurricane Juan in 2003, it will be a very stormy day. The conventional thinking would be that a tropical storm does not produce as damaging of a surge, but this time I beg to differ. The accelerating forward motion combined with 50-60 mph winds and the northeast angle will impact the entire coast of eastern Nova Scotia, including Halifax. The Atlantic will be pushed and piled up ahead of this storm, and I believe will result in a surge of 4-6 feet or possibly higher within small inlets. Though a tropical storm, this will look, feel and sound like a hurricane. Damage from downed trees will be considerable as Ophelia makes it’s first official landfall this weekend. Thanks to James, a reader from the Nova Scotia area, for reminding us that tropical cyclones often have a reach that goes well north of the U.S. and Ophelia will be no exception.

SUNDAY update: Nova Scotia did not see the strong winds and surge as predicted above, because the core of wind stayed offshore, much to the relief of residents I'm sure.

When I checked Ophelia's projected path this morning, I was stunned to see this map above. Can you believe this storm is going to maintain an impressive intensity all the way across the Atlantic... and possibly impact Scotland and Iceland? That is just "off the charts" as my students would say. The only other storm I can recall which had such a northerly track was Hurricane Gloria in 1985, which hammered Long Island and central New England, remained a tropical storm into the far North Atlantic, had after-effects in northern Europe into October. Read this well-done article that looks back on that fateful September storm.

Wednesday, September 14, 2005


Ophelia 5

I'm certain many people in North Carolina and Southeast Virginia do not consider this a "miss" as landfall is technically considered to be when the more than half the eye crosses over land. This Category 1 storm will turn out to cause as much damage as a Cat 2 or 3, because of the slow movement, long duration of onshore winds accompanied by heavy rain. The big problem for Eastern North Carolina is that all that water is being shoved up the sounds and rivers, and it will have no choice but to cause significant upstream flooding as it has nowhere to go. Couple that with 6 to 12 inches of rain on top of the surging water, and you have another significant flood event on the heels of the worst natural disaster in U.S. history. The NC governor was right to jump all over this storm early on, as the potential for inland flooding damage is just as great as storm surge damage along the coast. I don't recall a situation in recent times where a slow moving storm affected the Carolinas quite like this, unless you count flooding from Tropical Storm Dennis shortly before Floyd arrived in September 1999. Of course nothing in our time will compare to the ultimate slow moving catastrophic rainmaker that was Hurricane Mitch in October 1998 that devastated parts of central America under 3 feet of rain. More on the effects of Ophelia shortly.