Posted: 12:05 pm Thursday, August 22nd, 2013
By John Nelander
We don’t think of tropical weather affecting the U.S. West, since most Pacific systems either skirt the coast of Mexico or head west-northwest out to sea. In fact, only two tropical storms in the past 100 years have hit California directly.
But a few storms have impacted the area, and it’s not unusual this time of the year to see tropical moisture spread into the Southwest. That’s expected to happen this weekend.
The Atlantic is devoid of tropical systems. But heavy rain from a possible tropical storm brewing in the Pacific Ocean, Invest EP94, could inundate places like Phoenix and Las Vegas this weekend. The system, 500 miles south of Cabo San Lucas, Mexico in Baja Calif., is forecast to become Tropical Storm Ivo.
A few forecast models show the storm approaching extreme southern California. In any case, rain from the storm is forecast to trigger possible flash floods on Sunday and Monday.
The National Weather Service’s Weather Prediction Cener shows more than 2 and a half inches of rain falling in Western Arizona through the middle of next week.
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Sea Surface temperatures have warmed dramatically in the Atlantic north of the Lesser Antilles ovr the past month. Tropical storms this season have been battered by dry air and wind shear, and they continue to keep a lid on development as we approach the peak of the season.
But systems that do spin up over the next month or so may have more fuel for strengthening, according to sea surface temperature maps published by the National Oceanic and Atmospheric Administration’s Office of Satellite and Product Operations.
However, nothing was showing up in the GFS long-range forecasts, and the National Hurricane Center said tropical storm development was not expected in the Atlantic through at least Tuesday.
Ocean temperatures are now above normal north of the Lesser Antilles. (Credit: NOAA)
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A break in global sea level rise occurred in 2010 and 2011 when flooding rains hit Australia — dumping so much on the continent that oceans were literally robbed of water. It temporarily halted the trend of rising seal levels caused by melting ice, according to a new study by the National Center for Atmospheric Research (NCAR).
On other continents, the terrain would allow the water to run off and return to the ocean, researchers note. But Australia soaked it up, It caused the level of oceans to drop by about a third of an inch over an 18-month period.
On average, Australia received a foot of rain over average during that period.
“No other continent has this combination of atmospheric set-up and topography,” said NCAR scientist John Fasullo, lead author. “Only in Australia could the atmosphere carry such heavy tropical rains to such a large area, only to have those rains fail to make their way to the ocean.”
NCAR says global conditions have since “snapped back,” and now oceans are rising faster than before.
About the Author
John Nelander is a freelance writer, book editor and publisher in West Palm Beach. Weather Matters features news and observations about the weather with a focus on what's happening in South Florida. The blog also looks at the latest studies on climate change as well as what's happening in the weather forecasting biz. His website is www.pbeditorialservices.com.