Eastern Pacific Hurricane Watch - Is the 'Fat Lady' Tuned-up to Sing?
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Updated Sep 30, 2011 So have we reached the end of the Baja Hurricane season? The answer is an absolute ‘maybe’.
The Eastern Pacific Hurricane Season runs through November 30, but the real threat to Baja tapers of dramatically after the second week of October. The latest landfall of a tropical cyclone on the Baja peninsula is October 17. So statistically speaking, it is premature to say the threat is over.
Last year, the 2010 season, also generated fewer Eastern Pacific tropical cyclones than our average, and that season ended in late September when Tropical Storm Georgette limped across the southern portions of the peninsula with moderate winds and little rain. After the air mass over the peninsula ‘dried out’ several days after the storm our late fall weather, some of the best Baja has to offer, began.
The 2011 Hurricane season has certainly been a different one. We have had only 8 named tropical cyclones this season so far rather than our average of the last 7 years of 13.2. What is remarkable is that 50% of them have been Major Hurricanes, achieving Category 4 in all four cases. But the last 45 days, usually a very active period from mid-August through the end of September only generated Hurricane Hilary. With this same period the most dangerous for Baja Sur, we haven’t even had a close call yet this year.
Hurricane Dora was the closest approach of a tropical cyclone to Baja this year so far, way back in mid-July. Even that didn’t get too scary. The water temperatures well south of Baja were too cool to fuel a tropical cyclone and Dora had degenerated into a Tropical Storm when it was still several hundred miles south of Cabo San Lucas. Dora was once a very powerful Major Hurricane falling just one mile per hour short of being Category 5, but the air was too dry that early in the season over Baja and the prevailing upper level winds were still directing things to the west and Dora faded into history delivering only some scattered showers to the southwest most portions of Baja California Sur.
This season just didn’t shape up for those “wanna-be hurricanes”. The ITCZ or ‘monsoonal flow” remained fairly well south in the Eastern Pacific. The flow wanders like a drunken snake in the Eastern Pacific through the season moving north as the tilt of the earth warms the northern hemisphere and migrating back south, toward the equator as fall matures. We get our most serious threat to Baja when the ITCZ reaches its zenith and arches along the southern coast of Mexico and turns west near Puerto Vallarta. This year it only remained along the coast for the early part of September, already the ITCZ has begun to migrate south, hundreds of miles from its peak.
Early in the season the La Nina event we had been experiencing moderated and some even thought we would enter an El Nino event. But it turned out to be another ‘non’ year, of near normal SST’s near the equator. The National Hurricane Center predicted a slightly below normal year, and certainly in numbers of storms generated that was true, we are well below normal.
The ITCZ is also a pipeline, for those tropical waves of super stimulated air moving west from the deserts of Africa. I could not find any stats on the total number of waves generated and what was average, but these climatic effects are considered to be the seeds of tropical cyclones. By my count only three of them made it across the Atlantic and over mainland Mexico to the Eastern Pacific. Two formed hurricanes, the other Tropical Depression 8E which moved ashore near Acapulco and fizzled over land. I recall so many wide angle weather charts during my 8 seasons of Hurricane Watch where we would have 4-6 tropical waves between the western side of the Eastern Pacific and the west coast of Africa. Nothing of the sort happened this season.
The air mass over the southern portions of the peninsula has remained dryer than usually. We have only had a few days of evening thunderstorms here in La Paz, usually generated by moisture drifting west from the mainland. We did not receive enough rain fall to even come close to our yearly average, making this the 4th year of drought in Baja Sur.
I am not going to say too much about this week’s 30 day SST Analysis and SST Anomaly charts this week, as Hurricane Hilary was about ½ way through her work when the data for these graphics was compiled. The Sea surface temperatures shown here will be completely irrelevant by now. The one area of interest more to fishermen than storm watchers is a rather large area of warmer than normal waters exists along the Baja shored of the Sea of Cortez from the Bay of La Paz and southwest from East Cape. This area is 1°C warmer than normal.
Hurricanes are nature’s mechanism for redistributing equatorial energy northward. I think Monday’s new graphics will show great cooling along the path of Hilary. Hilary took enough energy from the region that generates storms of the greatest threat to Baja at the peak of our threat period. In short, there may not be enough ‘fuel’ left there to generate another storm before we are off the hook for this year.
When we look at the wide angle surface chart it adds to our security here in Baja. Tropical Depression Hilary (magenta arrow) is dissipating off the western edge of this map. In the Atlantic Hurricane Ophenia is a monster Major Hurricane in the mid Atlantic which will brush by Bermuda and Newfoundland before heading off to Europe. Tropical Storm Philippe is a little late season ‘light in the loafers’ storm that is currently forecast to never amount to much of anything. There are no additional tropical waves in the pipeline, all the way back to the deserts of Africa.
More below...
So now for the fun part, my prognostications for the week ahead. I don’t think I need to roll the bones, read the tea leaves or consult my Ouija board this week.Outside it has never really FELT like hurricane season this year and I think we will escape landfall of a tropical cyclone. I don’t think we will see another tropical cyclone in the Eastern Pacific before mid month, when Baja is pretty much off the statistical hook for tropical cyclone threats. Instead of any inclement weather predictions I will venture a guess that by late this weekend our weather will break, the little humidity we have had of late will vanish and some of the finest weather Baja has to offer will onset by mid week. If you love outdoor activity in the Sea or anywhere in Baja it will be time to come visit us very soon. But what do I know...
I’ll write here at least one more time before Baja's 2011 Eastern Pacific Hurricane Season is over. Thanks for reading and see you next week!
Tomas Zyber
Our Eastern Pacific Hurricane Watch is an editorial/entertainment analysis of data from the National Hurricane Center, NASA and NOAA and is based on information and research provided by the same, but is an amateur endeavor. For actual storm information readers should refer to notices and warnings posted by the National Hurricane Center. or visit the Mexican Nation Metrological website for more information.
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