Category 1 Hurricane Blanca Losing Strength as it Heads Towards Baja Mexico

Hurricane Blanca, a Category 1 storm with 90 mph winds at 11 am EDT Sunday, is steadily losing strength as it heads north-northwest at 12 mph towards Mexico's Baja Peninsula. Satellite loops show that Blanca has lost its eye, and the cloud pattern has assumed an elongated oval shape in the face of wind shear that has risen to a moderately high 15 - 20 knots. Cooler waters and a drier surrounding air mass should continue to cause steady weakening, and Blanca should be a weak tropical storm when it makes landfall in Mexico's Baja Peninsula on Monday. Cabo San Lucas on the southern tip of the Baja Peninsula will likely see winds no stronger than 50 mph as Blanca makes its closest approach, and heavy rain rains will be the main threat to Mexico's Baja Peninsula from Blanca. Moisture from Blanca will flow into Southern California, Arizona, and New Mexico beginning on Tuesday, bringing localized rains of 1 - 2 inches. An Air Force hurricane hunter aircraft will investigate Blanca on Sunday afternoon.


Figure 1. Hurricane Blanca as seen on June 5, 2015 from the International Space Station. Image credit: Terry Virts.


Figure 2. Predicted total precipitation from the 06Z Sunday run of the GFDL model. Widespread areas of 2 -4" were forecast along the Baja Peninsula. Image credit: NOAA/GFDL.

Record-early tropical-storm impacts possible in Baja California
Should Blanca deliver winds of tropical-storm strength to Baja California, it would be the earliest such occurrence since the beginning of modern tropical cyclone records for the Northeast Pacific in 1949. Between 1949 - 2014, only two tropical cyclones have made it within 100 miles of Baja California prior to July. One of these was a tropical depression in 1993 that slid north along the eastern coast of the peninsula, dissipating just east of La Paz. The other was a hurricane that cut just south of the peninsula at minimal Category 1 strength on June 14, 1958. The earliest named storm to hit Baja was Tropical Storm Calvin of 1993, which made landfall south of La Paz on July 8 as a weak tropical storm with 45 mph winds. This year looks set to carve many more marks in the history of Northeast Pacific tropical cyclones, given the unusually warm SSTs that prevail as well as the continued strengthening of El Niño, which favors hurricane development in this basin.


Figure 3. Tropical cyclones observed between January and June since modern records began in the Northeast Pacific (1949). Image credit: NOAA Historical Hurricane Tracks.

New Northeast Pacific disturbance may develop near Mexican coast
An area of low pressure has formed in the Pacific a few hundred miles southwest of Mexico/Guatemala border, and has the potential to develop into a tropical depression late this week. The 00Z Sunday run of the European and UKMET models predicted that this disturbance would develop into a tropical depression by Friday and begin bringing heavy rains to the southeast coast of Mexico by Thursday. The Sunday morning runs of the GFS model did not show the disturbance developing. In their 8 am EDT Sunday tropical weather outlook, NHC gave 2-day and 5-day odds of development of 10% and 60%, respectively. It is possible that moisture from this disturbance could flow northwards into the southwest Gulf of Mexico's Bay of Campeche early next week, boosting the chances of a tropical disturbance capable of forming into a tropical depression there.

Links
Live streaming camera on the very southern tip of Baja California.

Another camera is just east of this one, on the Bay (Bahia) of San Lucas at Sunset Da Monalisa.

Jeff Masters and Bob Henson