Emilia intensifies into a major hurricane; Daniel hanging on; New disturbance forms
After intensifying into a hurricane last night, further strengthening has occurred and Emilia is now the third major hurricane of the 2012 Pacific hurricane season. As of the latest public advisory from the National Hurricane Center, Emilia was located at 13.3 °N 112.2 °W (position accurate within 10 nm), or about 680 miles south-southwest of the southern tip of Baja California. Maximum sustained winds have increased to 120 mph and the minimum barometric pressure has fallen to 959 millibars. Emilia is moving west-northwest at 14 mph parallel to the coastline of Mexico. Geostationary imagery reveals that Emilia is close to Category 4 intensity, with cloud tops cooler than -70 °C wrapping fully around the eye. In fact, the UW-CIMSS Final CI# is T6.0/135 mph. A few factors preventing the upgrade include the fact that both SAB and TAFB back with Final CI# numbers of T5.5, and the eye is not completely cleared out. I expect the system to attain Category 4 intensity at the next advisory as new values from SAB and TAFB will have come out by that time.
Figure 1. Dvorak satellite imagery of Major Hurricane Emilia.
The forecast for Emilia
Emilia is forecast to continue to strengthen over the next 24 to 36 hours as Sea Surface Temperatures are expected to remain above 26 °C, wind shear is expected to remain below 20 knots, and the cyclone should continue to pass over relatively high Oceanic Heat Content that extends to a great depth. The official forecast below remains slightly above the National Hurricane Center's through 36 hours, which is in return well above much of the model guidance. Thereafter, a combination of cooler Sea Surface Temperatures and a more stable air-mass should slowly weaken Emilia. It should be noted that an Eyewall Replacement Cycle could occur at any time over the next 36 hours, and there is very little skill in predicting these. If one were to occur, it will play a significant role in the forecast of the system through the rest of the forecast period. Eyewall Replacement cycles are common in strong hurricanes, especially major ones.
The hurricane continues to the west-northwest as forecast. This motion is expected to continue over the next couple of days before a gradual turn towards the west occurs due to the intensification of a mid-level ridge of high pressure to its north. The forecast for this discussion remains virtually unchanged from the others and lies in close proximity to the average of the multi-model consensus.
...FORECAST POSITIONS AND MAX WINDS...
INIT 10/0300Z 13.3N 112.2W 105 KT 120 MPH
12H 10/1200Z 14.0N 113.8W 120 KT 140 MPH
24H 11/0000Z 14.7N 115.8W 125 KT 120 MPH
36H 11/1200Z 15.1N 117.4W 100 KT 115 MPH
48H 12/0000Z 15.7N 119.9W 80 KT 90 MPH
72H 13/0000Z 16.3N 123.1W 65 KT 75 MPH
96H 14/0000Z 17.2N 127.4W 50 KT 60 MPH
120H 15/0000Z 17.6N 131.8W 45 KT 45 MPH
Farther to the west, Daniel remains a minimal hurricane. It truly is the storm that could. As of the latest advisory from the NHC, maximum sustained winds were unchanged from the previous advisory at 75 mph, and the pressure remained 992 millibars. Daniel is moving due westward at 15 knots, and this motion is expected to continue until dissipation. The system should slowly weaken over the next few days, and will likely enter the Central Pacific Hurricane Center's area of responsibility between 36 and 48 hours out as a mid-grade tropical storm. Dissipation south and west of Hawaii is a good possibility by 96 hours out.
An area of low pressure to the east of Emilia has formed this evening. Geostationary imagery reveals that the disturbance remains disorganized, and is likely being sheared by the outflow produced by Hurricane Emilia. As the cyclone pulls away, a more favorable environment for intensification should present itself, and that should allow this system to develop. The National Hurricane Center is currently giving this area a medium chance, 30%, of becoming a tropical cyclones. You may be somewhat surprised to see that I believe these chances are lower...near 10%. Any development of this low will be slow as it moves west-northwest parallel to the coast of Mexico.