Public Advisory Edit



400AM CDT THU FRI 12 2015



LOCATION...14.7N 100.6W





At 1000 pm CDT, the center of Tropical Storm Carlos was located at 14.7N 100.6W, or about 15 miles (270 km) south-southeast of Acapulco, Mexico. Maximum sustained winds were 50 knots (0 mph; 95 km/h), with higher gusts. The minimum barometric pressure was 995 mb (hPa; 29.40 inHg), and the system was moving north-northwest at 2 knots (2 mph; 4 km/h). Atmospheric conditions are favorable for further intensification, and the system is likely to become a hurricane by daybreak, and possibly into a major hurricane this weekend or early next week as it parells the coast.

Interests in the tourist resorts of the Mexican Coast are advised to continue to watch the progress of the Carlos.

A Tropical Storm Watch is in effect for...

  • Acapulco to Zihuatanejo

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

For storm information specific to your area, please monitor products issued by your national meteorological service. NEXT ADVISORY

Next complete advisory at 1000 am CDT.


Forecaster YE

Discussion Edit



400AM CDT FRI JUN 12 2015

Tropical Storm Carlos remains a well-organized tropical cyclone. At around 9z, a big burst of deep convection was noted to the south of the center, resulting in an increase in objective estimates. Although we have no additional microwave data, Carlos is likely slowly intensifying. The storm’s outflow is pretty good, and cloud tops are near -80C or cold medium gray on the Dvorak IR satellite. However, all the deep convection is restricted to the south side of the well-defined center, which is an indication that despite its impressive structure, up to 20 knts of shear is affecting the system from the north. This is supported by CMISS diagnostic and the SHIPS model initialization (which based on the GFS). Based on 3.5/55 knts from TAFB, and 3.0/45 knts (though CI values, thanks to a highly questionable classification of 3.5/55 knts 12 hours ago from SAB), and 3.3/49knts CI value at 7z from ADT, the intensity is assigned at 50 knts. A pressure of 995mbar is assigned based on recent ADT estimates.

Little change to forecast track is necessary. The models if anything have shifted northward this cycle, although this shift is not major. A weakness between two high pressure areas, one expected to bring record heat the Southeastern United States and another off the coast off Baja California Norte is expected to steer Carlos west-northwest over the next few days. Thereafter, the aforementioned ridge extending from the open East Pacific into northern Mexico is expected to build further eastward, with the flow around that anticyclone forecast to direct Carlos at a faster pace, but still moving west-north. Towards the end of the period, a turn to the northwest is expected as it approaches a weakness in the ridge induced by a weak trough over the Central United States and/or the separation between the above two ridges. The new forecast track lies a bit to the west of the previous one, and is a blend between the TVCN and the GFS ensemble mean.

Even though the forecast track is clearer cut now than 36 hours ago, there remains uncertainty on the storm intensity. The GFS model, which has been the best performer when it comes to intensity this year, is a bit more realistic at the 0z run. It shows slow intensification through around 48 hours due to the presence of moderate to strong shear, which is forecast to relax a little overnight, before intensify again tomorrow as reflected by the 0z SHIPS index. After around two days, the shear could relax again, which may result in a faster pace of intensification, and this is reflected in the forecast below. After day 3, despite the continued relaxing of shear, dry air intrusions and inner core dynamics could result in large fluctuations in intensity, typical of Category 2, 3, or 4 East Pacific hurricanes. As such, it is very difficult to determine the precise timing of the peak intensity of this hurricane. Even though Carlos has very high potential due to the warm waters and slowly subsiding shear, due to the above timing uncertainties, major hurricane status is not outright predicted, but remains a somewhat likely event. However, it is worth pointing out that peak intensity, and thus major hurricane strength is not that likely to occur at the below forecast points, as East Pacific intense hurricanes most often peak around 15z. Still, this forecast is above the intensity guidance, aside from the GFS, even though the intensity guidance is highly unreliable in the East Pacific, especially the more conservative guidance. However, it is worth noting that both the SHIPS and LGEM statically guidance has trended way downward the past few runs, which seems puzzling given the favorable conditions. The LGEM keeps this a tropical storm, while the SHIPS calls for a low-end hurricane.

Several hours ago, the government of Mexico issued a tropical storm watch for a portion of the Mexican coast, specifically from Acapulco to Zihuatanejo. Additional watches and warnings may be required if this storms gets larger than expected, which is not necessarily typical of intensifying East Pacific tropical systems. As mentioned in previous packages, this storm is a land threat. Over the next several days, in part due to the storm’s expected slow motion, up to 6-12 inches of rain could fall in the states of Chiapas, Oaxaca, Guerrero, Colima, Michoacán, and Jalisco, with higher totals possible over the higher mountains of the aforementioned states. Up to 10-15 foot waves are also possible along coastal seas, along with wind gusts near or at gale-force.

Looking ahead, both the American and European model systems, bring a weakening but formidable Carlos into the southern Gulf of California (north of Jalisco) by midweek, and has the storm passing very close to Baja California Sur in around a week’s time frame. In fact, the 18z GFS run brought the storm as a bona fide hurricane near San Jose del Cabo. This is very close the landfall location of the legendary Hurricane Odile of the 2014 season. Furthermore, the 0z GFS brought this storm very close to Todos Sanots at similar intensity in about a week. While tourists and locals in both the Western Mexico coast and Baja California Sur are advised to continue to keep an eye on Carlos, there is high uncertainty. As such, users are reminded to not focus on the exact track since a hurricane is not a point, and dangerous conditions can and will exists several hundred miles from the center.

Initial 14.7N 100.6W 50 knts

12 hr 15.0N 100.7W 60 knts

24 hr 15.2N 101.0W 65 knts

36 hr 15.4N 101.2W 70 knts

48 hr 15.8N 101.7W 75 knts

72 hr 16.5N 102.9W 90 knts

96 hr 17.6N 104.8W 90 knts

120 hr 19.4N 106.6W 90 knts


Forecaster YE

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