Teenager. Weather aficionado. Soccer fan. Realist. Posts subject to sarcasm. Goal: National Hurricane Center.
By: TropicalAnalystwx13 , 4:52 PM GMT on June 17, 2012
After putting on an impressive bout of rapid intensification on Friday--one that allowed the hurricane to peak as a 105 mph Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale--Carlotta slammed into Mexico as a Category 1, producing wind gusts over 111 mph, several inches of rain which caused flooding and mudslides, and structural damage. Satellite imagery a few hours before landfall revealed a well-defined eye embedded within a symmetrical Central Dense Overcast. Final T-numbers from CIMSS-ADT were 6.2, 6.3, and 6.3, respectively. This supports an intensity of 130 mph. However, considering that these numbers are usually slightly bullish, I believe that Carlotta briefly peaked as a 115 mph Category 3 hurricane. How strong the hurricane peaked as will ultimately be determined in post-season analysis. Now, Carlotta is nothing but a remnant low interacting with a few thunderstorms along the Pacific Coast of Mexico. This is no threat to develop and this will be the last time Carlotta is mentioned, barring anything unexpected.
Figure 1. Visible satellite imagery of Hurricane Carlotta at peak intensity. The system weakened slightly before landfall, down to 90 mph, making it a Category 1 hurricane at landfall.
Watching Invest 95E
Succumbing to strong wind shear a few days ago, Invest 95E was deactivated by the National Hurricane Center and was not supposed to be an area to watch for any tropical development. However, an apparent decrease in wind shear yesterday has allowed the disturbance to organize slightly and many of the global models show the system attaining tropical depression status before it moves into Mexico in a few days. The latest Tropical Weather Outlook from the National Hurricane Center gave the disturbance a low chance, 10%, of becoming a tropical cyclone over the next 48 hours. At this time, I am giving 95E a medium chance, 30%, of becoming a tropical cyclone over the next 48 hours. The latest SHIPS model analyzed a moderate 15 knots of shear over 95E, but it shows a decrease in shear between 12 and 48 hours out, the same time-frame in which the global models show organization. The main limiting factor after 48 hours out will be dry air. It's quite likely that this disturbance, whether it stay just that, or become a tropical depression, will impact the Mexican coastline in a few days, so residents there need to be on alert.
Figure 2. Visible satellite imagery of Invest 95E.
Atlantic heating up
A non-tropical area of low pressure located about 120 miles south-southwest of Bermuda (per the latest TWO) has potential to become the 2012 Atlantic hurricane season's third tropical cyclone of the season. The disturbance lies over Sea Surface Temperatures of 24-25 °C, cooler than the values needed to sustain a tropical cyclone, but warm enough to sustain a subtropical cyclone. Visible satellite imagery reveals a distinct spin embedded on the southeast side of the "cloud bank" and the disturbance has shown signs of organizing somewhat this morning. One limiting factor will be its proximity to a large upper-level low to its southwest which is producing 30-50 knots of wind shear atop the disturbance, and another being that it lacks low-level convergence. However, as the system moves towards the northeast and eventually north, it appears it could briefly enter an area of low wind shear, which may allow the disturbance to organize. The global models do indeed show further organization of this area of disturbed weather, and a look at the FSU Cyclone Phase Diagrams reveal that they show it generally neutral, or subtropical, in nature...exhibiting both tropical and subtropical characteristics. This disturbance should pose no threat to the United States, and will eventually become absorbed by a larger extratropical low pressure area in roughly 5 days. I am giving this area a low chance, 20%, of becoming a tropical cyclone over the next 48 hours.
Figure 3. Visible satellite imagery of the North Atlantic, showing the non-tropical low pressure area near Bermuda.
Tropical development in the Bay of Campeche this week is still looking very plausible. Satellite imagery loops reveal that the MJO (Madden-Julian Oscillation) has entered Phases 8 and 1, depicted by a significant increase in tropical moisture across the West Atlantic and East Pacific. The National Hurricane Center's Surface Analysis Map reveals a tropical wave centered over the Central Caribbean, and this is producing a large area of disturbed weather. The development of an entity in the Gulf of Mexico over the coming days appears to be from the combination of this wave, remnant energy from ex-Carlotta, and increased moisture thanks to the upward pulse of the MJO. Global models are beginning to latch onto this disturbance once again, with the GFS remaining the most bullish. It does appear that whatever forms in the Bay of Campeche this week has the potential to organize into a formidable tropical storm at least, due to a large anticyclone forecast over the Gulf. While it is too early for specifics, it also appears that this disturbance could pose a threat to the United States. I am currently giving the tropical wave a low chance, ~0%, of becoming a tropical cyclone over the next 48 hours, and the potential tropical cyclone in the Gulf a high chance, 60%, of ever developing. Residents along the West Gulf coast especially need to be on alert over the coming days for potential tropical mischief.
Figure 4. Visible satellite imagery of the West Atlantic, showing the tropical wave in the Central Caribbean Sea.
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