Eastern Pacific Hurricane Watch -  The Quiet before a Storm?

So, it's been another quiet week for storms formation in our own basin. The approaching first two waves really aren't given much chance of developing into anything before moving west of 110°W. Once storms are that far west it becomes unlikely that we need to worry about them.

Usually, by this point in the season we have had 10 named storms, so far this season only 6. We've only had two hurricanes and both of those were well out into the Pacific. Usually by this time of year 6 have formed inside of 110°W, this year just two have formed in that region.

One reason may be La Nina. Take a look at the SST Anomaly graphic below. Now how, over the last month, an increasing amount of blue or colder water is appearing at the bottom of the frame. This colder water may be drawing air SW at upper levels through the Tehuantepec and southern Mexico across the area of ocean where the more easterly systems form. Click here to see an animation of the visible light satellite view of the eastern Eastern Pacific. At the time of this article all the cloud tops across most of the visible region are smeared to the SW. This indicates the clouds are boiling up to higher altitudes, only to be swept to the SW. Tropical cyclones need quieter air to establish the cyclonic column that feeds the storm.

More below...
 

SST Anomaly

The colors represent deviation of this years water temperatures from the norm. Green is normal, blue colder than normal and yellow warmer than normal waters.

Otherwise, when we look at the Sea Surface Temperature Anomaly graphic we don't see anything too alarming. Much of our Hurricane Birthing Zone is slightly above normal temperatures, further out in the Pacific some areas are a slight 1°C above normal. Water just south of Cabo San Lucas toward the mainland is just about seasonal. Once up into the Sea of Cortez, we do find some areas that are more than 1°C above normal. But since the Anomaly graphic is more of a strategic look at storm formation, the water deep in the Sea becomes irrelevant, as if a storm gets that far, we're already in trouble!

Over the next 72hrs the Pacific High is again forecast to extend a ridge southeastward toward Baja. this will provide dryer air, some winds from the north and perhaps some slightly cooler temperatures. All these positive climatic aspects also lead to ta lesser chance of a tropical cyclone threat.

SST Analysis

Tropical cyclones thrive in waters warmer than 26° C and degenerate in waters below that temp. Areas south and east of the red line have the potential for a tropical storm strike

Lets turn our attention to the SST Analysis. The 26° thermo cline shown on the graphic left by a red arrow is another sign that we are in the threat season for Baja. Water warmer than 26°C is an integral part of storm formation and growth. Once crossing into waters below that temperature storms degrade very quickly. The magic line now encompasses then entire tip of Baja, up as far north in the Pacific as Magdalena Bay. This is just about normal for this time of year.

Current forecasts call for the two tropical waves to stimulate some activity, but development is expected to be slow to occur close to the coastline.

So now the fun part, my prognostications. Last week I called for a Hurricane to form east of 110°W from the second wave of this batch to cross into our basin. Well, I'm not wrong, at least not yet. It just hasn't happened yet. Because last weeks Hurricane Watch was later in the week and this one being early, I get a Mulligan for last week prognostications.

This week, I'm gonna back down from that forecast of a hurricane inside 110°W. I am going to bet on that high level SE flow to continue and knock the tops off of any cyclonic activity that tries to form near the Mexican mainland. I think we're going to get two tropical cyclones out of these three waves, but none of them will move to the NNW soon enough to scare us. But remember, what do I know...

But we need some rain!

Clear skies and fair winds!  
Tomas

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 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.