Eastern Pacific Hurricane Watch -  TS Barbara Makes Landfall then Quiet

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

Despite being capable of massive destruction, these engines for dispersing equatorial energy from the sun are actually very delicate and just the right conditions have to exist for these storms to form and survive.

Ocean Surface Temperature is critical. Surface temperatures below 26°C are virtually incapable of supporting cyclonic activity. I say virtually because the first named storm of this years Atlantic Hurricane Season occurred before the usually June 1 beginning of the season and, as a subtropical cyclone, lived and died in water below that 26°C mark. Once a tropical cyclone crosses into water below that mark they are usually short lived, degenerating in less than 24hrs. This is why we track that magic 26°C thermo cline. This week when we look at the progression of the Sea Surface Temperatures we can see the effects of  Alvin and Barbara.

Cooler waters continue to migrate south along the outside of Baja while the Sea of Cortez begins to warm up. When you look at the 26° thermo cline it now divides the Sea almost in half with the warmer waters being found along the coast of the mainland.

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.

Looking at the Sea Surface Anomaly graphic we can see that nearly the entire Pacific Basin has returned to near seasonal normal temperatures. Barring a small area SW of Acapulco which is just 1°C above normal it would appear that the two early tropical cyclones expended the amount of kinetic energy that had brought the ocean to levels above normal. This would indicate that at least the oceans are providing an average likelihood of storm formation.

Humidity has begun to climb in Baja Sur over the last few days. With moisture overhead providing some cover from the sun, even at midday, the slightly lower temperatures have been offset by the sticky late summer prelude. As our Baja hurricane threat approaches after the middle of August the humidity levels will climb even higher. We had significant clouds over the mountain areas this afternoon. Folk forecasting calls for rain in La Paz 30 days after the first rain in the mountains. Considering that may have occurred today, the lower elevations can probably expect the first monsoon rains around the middle of July. This would be right on target with rainfall statistics.

Wind patterns in Baja are still to dramatic, with the difference between Pacific, Land and Sea temperatures. As the water warms around Baja it will not only support cyclonic activity but provide an air mass less active with fewer winds to shear the cyclonic lift column.

Now for the fun part, looking at the chance of storm formation in the two weeks ahead. In our May 30th forecast we have to boast a 100% accuracy. Alvin fizzeled, Barbara never made hurricane status and it was the very end of the forecast period that the first tropical wave stimulated any kind of tropical activity, TD3E. looking ahead I think it unlikely that we will have a repeat forecast. Even though there are a parade of Tropical Waves marching through our basin there is limited thunderstorm/unstable air for these supercharged air masses to stimulate. As the tropical waters will continue to warm up that is going to change. I expect we will get through the weekend before another systems kicks up. This early in the season it will probably just make hurricane status before it moves harmlessly west into the Pacific. The ITCZ has resume it's early season flat motion across the basin and should keep these waves away from the south coast of Mexico, where Barbara formed. However, in about 10 days, near the end of this outlook period, there should be a significantly larger amount of kinetic energy waiting to be turned into a tropical clone and we'll probably see another form along the coast and move off WNW into the Pacific. Whatever the tropical forecast it's not likely that those of us here in Baja will need to break out the storm shutters!

Until June 26th... Clear skies and fair winds!   Tomas

Our Eastern Pacific Hurricane Watch is an editorial 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.