Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
Reged: Sun
Posts: 2565
Loc: Melbourne, FL
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Patterns and Predictions
Sun Aug 07 2005 10:48 PM
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In terms of activity, if July seemed more like September (and it did), then in terms of overall pattern, early August seems more like mid October. Areas of unusually strong shear dominate the central Atlantic and the area from the Bahamas to Belize. An upper level low is churning near the Bahamas (and is worth keeping an eye on). Tropical Storms Harvey and Irene have been fighting wind shear for most of their existence - and they still are. A trough that was off the west coast of Africa has drifted westward but it will still have a disruptive influence on anything exiting west Africa - at least for a while longer. The tropical waves over Africa are not as numerous (and thats good) and they are exiting at a higher latitude (12N to 15N) and thats also good since it will probably make 'fish spinners' out of anything that exits the African coast in the near term.
The Bermuda and Azores Highs are weak and shallow - and displaced to the north of their normal seasonal positions, so anything that does stay on a southerly track is not going to race across the pond. So far, the MJO has performed like a bad model this season and I have pretty much discarded it. From the 10th of July through the remainder of the month the MJO was not favorable for storm development from the east coast of Africa westward to the west coast of North and South America - and yet look what happened in July (I guess that nobody told those seven storms that conditions were not favorable). Today the MJO does show a positive area for development in the central Atlantic - but probably because of Harvey and Irene rather than anything to do with their development. But that pattern should change to one that is more favorable for development in a few weeks.
SSTs are not uncommonly warm in the Atlantic, but the bigger surprise is in the Pacific ENSO region. The earlier forecast for the Summer was for neutral conditions in the tropical Pacific - perhaps even for a weak El Nino by August. Instead, the latest forecast calls for a weak La Nina to develop, starting this month, and last through the Winter. If this La Nina materializes it will certainly support a more active tropical cyclone season in the Atlantic. It is worth noting that a cooler Gulf, western Caribbean and southeast U.S. Atlantic is also predicted - which could mean that a late season storm would have difficulty in forming.
Well that about covers the patterns (and I'm sure they will change) - now lets look at the numbers. In checking out the past 60 years, it is common for a month of high activity to be followed by a slower one - and August will probably do just that given the chaotic state of the Atlantic basin at the moment. A few days ago, NOAA released their update for the 2005 season and increased the number of storms to 18-21. On Friday Dr Gray did the same and he now expects the final tally on this season to reach 20 named storms, 10 hurricanes and 6 major hurricanes. If these forecasts verify it would make 2005 one of the most active seasons ever recorded.
Earlier in the year I had expected the season to be a busy one, perhaps even a remarkable one, but had kept my initial numbers on the low side. After a July with 7 named storms (a record), it was time to take a serious look at how the rest of this season might evolve...and the numbers are chilling to say the least.
There are only 4 years in the historical record where significant storm numbers have been recorded. Those years are 1877 (19 named storms, 11 hurricanes, 2 major hurricanes), 1933 (21/10/5 - the busiest season ever), 1969 (18/12/5) and 1995 (19/11/5). In three of those seasons, at least one hurricane hit Florida and in two seasons (1933 and 1995) two hurricanes hit Florida. Other hurricane landfall areas during these milestone seasons were South Texas, Louisiana and North Carolina. This year we have already had two major hurricanes and one of them hit Florida (Hurricane Dennis on Santa Rosa Island in the panhandle) and another came close to South Texas with impact on northeast Mexico. Here are what those four seasons looked like in terms of monthly storm activity:
1877: thru July - 5; August - 2; September - 3; October - 6; November - 1; December - 2
1933: thru July - 5; August - 7; September - 5; October - 3; November - 1
1969: thru July - 1; August - 5; September - 6; October - 5; November - 1
1995: thru July - 5; August - 7; September - 3; October - 4
At a minimum I expect this year to have at least 19/10/4 with a possible outside maximum of 24/12/6 (although this high total is not very likely). My outlook for the remainder of the season is as follows:
2005: thru July - 7; August - 4; September - 6; October - 3; November - 1; December - 1
Thats an expectation for 22 named storms, 11 hurricanes and 5 major hurricanes - and a new record of storm activity for the Atlantic basin. It may not quite make it, but it'll be close - the busy Summer will quiet down a little in August, but I expect it to go back into high gear again in September. If we should make it to that 22nd storm, its name will be Alpha. Totals can certainly vary from month to month. We may not get a rare December storm, but we might get two in November or even four in October if the pattern changes at a later date.
The message is simple - the season is off to a record setting pace. It may not happen, but it will come close. Are you prepared? If not, take advantage of this slow period in August to get ready - just in case.
ED
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