The nineteenth tropical cyclone of the Eastern Pacific formed over this past weekend, and strengthened into Tropical Storm Patricia. The GOES-11 satellite captured Patricia from her “birth” several hundred miles south of Baja California, to her track there today, Tuesday, October 13.

The National Hurricane Center has posted a tropical storm warning for the southern portion of the Baja California peninsula from Buenavista to Agua Blanca, including Cabo San Lucas. A tropical storm warning means that Tropical storm conditions are expected within the warning area, generally within 24 hours.

A tropical storm watch remains in effect for the Baja California peninsula along the east coast from north of Buenavista to La Paz And along the west coast from north of Agua Blanca to Santa Fe. A Tropical storm watch means that tropical storm conditions are possible within the watch area…generally within 36 hours.

Patricia is expected to produce total rainfall accumulations of 1 to 3 inches across the extreme southern portion of Baja California.

On October 13 at 11 a.m. PDT, Patricia had maximum sustained winds near 60 mph with higher gusts and could strengthen a little. Patricia was 120 miles south-southeast of the southern tip of Baja California, near 21.4 North and 109.0 West. She’s moving north-northeast near 7 mph, but is expected to turn away from the Baja toward the northwest later today or tonight. Estimated minimum central pressure is 997 millibars.

As Patricia was approaching the southern tip of Baja California, the Geostationary Operational Environmental Satellite (GOES-11) has been watching her. GOES-12 is operated by the National Oceanic and Atmospheric Administration, and the NASA’s GOES Project, located at NASA’s Goddard Space Flight Center, Greenbelt, Md. created a movie of Patricia’s approach to the Baja over the past weekend.

This movie was created using satellite imagery from Oct. 9-13 from GOES-11. It shows Tropical Storm Patricia forming some 400 miles south of the southern tip of Baja California and tracking north. The movie ends on October 13 at 1500 UTC (9 a.m. PDT) when Patricia’s clouds have overspread the southern tip of the Baja.

Patricia looks somewhat disorganized this morning and the overall circulation also appears to be elongated from north to south.

The National Hurricane Center noted that Patricia is currently in a light vertical wind shear environment over warm water…so there remains the possibility of strengthening. The new track brings the center closer to Southern Baja California with the closest approach between 8 p.m. PDT tonight and 8 a.m. PDT Wednesday morning.

Tropical Storm Nepartak is now speeding in a northeasterly direction in the northwestern Pacific Ocean, where it is becoming extra-tropical and developing frontal qualities.

The last official position of Napartak from the U.S. Navy’s Joint Typhoon Warning Center was on October 13 at 6 a.m. EDT, when the storm was 605 nautical miles east-northeast of the island of Chichi Jima, Japan. That’s near 31.5 North and 154.3 East. Nepartak was speeding to the northeast at 33 mph (29 knots) and it had maximum sustained winds near 46 mph (40 knots).

Animated multispectral imagery showed Nepartak was beginning to develop frontal characteristics, which is a sign that the circulation will soon fade. Before it becomes a front, however, it is expected to continue transitioning into an extra-tropical storm, and dry air in the mid-levels of the atmosphere is helping that happen.

The Atmospheric Infrared Sounder (AIRS) flies on NASA’s Aqua satellite and captures infrared images of tropical cyclones take the temperatures of thunderstorm’s cloud top t  emperatures to determine their strength. Aqua and AIRS flew over Nepartak on October 12 at 11:35 a.m. EDT, and noticed that the storm was already starting to take on an elongated shape, indicating a transition to more of a frontal system.

How does infrared imagery know how high clouds are in the sky? The coldest ones are higher in the sky (because in the troposphere, the lowest layer of atmosphere where weather happens, temperatures fall the higher up you go until you get to the stratosphere).

The highest clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F) and second highest level of clouds are about 240 Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone. Although Nepartak still had some strong convection, it is expected to wane soon with the transition into extra-tropical status. Nepartak is forecast to continue speeding northeast in the next day or two, when the transition should be complete and Nepartak will be no more.