I have heard that an El Nino is now occurring. What are the likely weather consequences?
El Nino, a warming of tropical Pacific Ocean waters, causes changes in planetary wind patterns that have major effects on global weather. When strong El Nino events occur, as in 1997-98, temporary climatic disruptions are widespread and, in some locations, the consequences are devastating.
Climatologists estimate the 1997-98 El Nino brought abnormal weather to 80 percent of the Earth. At Chicago, the “El Nino winter” of 1997-98 was exceptionally mild and relatively storm-free, but elsewhere there were weather disasters. A few examples: Floods swamped California, Peru and central Africa; droughts ravaged southeast Asia, Australia and Brazil. Worldwide, the 1997-98 El Nino was responsible for 2,100 deaths and $33 billion in property damage.
While we look back at a cool, cloudy summer and begin fall cooler than average, hot & dry weather continues out west. Fires in southern California have burned more than 100,000 acres. Los Angeles will hit a high near 95 today. For the latest forecast, click here.
To see the latest image from Mt. Wilson, home of several tv & radio transmission towers and cell phone antennas, check out this webcam.
To see more pictures like this one from the Los Angeles Times, click here.
September’s arrival signals that meteorological autumn is under way. Weather records closed overnight on one of the area’s truly peculiar summers. It ended with a string of daytime highs that failed to reach 70 degrees at a time of the year when upper 70s are common. An August that closes with five back-to-back days during which the temperature failed to break out of the 60s hasn’t occurred here in 118 years. The summer season hosted 18 such days—more than triple the average of five such days.
Summer short on sun
But perhaps one of this summers most lasting legacies was its lack of sunshine. Summer 2009 goes down in the books as the cloudiest on record. Never since sunshine records began 115 years ago has a June-through-August period hosted less of the possible sunshine. Sunshine is measured in minutes and the summer’s total was 42,887 of the season’s possible 80,626 minutes of sun, or 53 percent of possible sunshine—67 percent is considered normal.
Days continue to shorten in September, taking a toll on temperatures. 120 minutes of sunshine disappears by month’s end and normal highs fall from 78 to 69-degrees.
Powerhouse Hurricane Jimena with near Category 5 strength 155 m.p.h. sustained winds continues churning toward the Baja California peninsula. Cabo San Lucas is among the areas under a hurricane warning.
What are the largest and smallest tropical cyclones (by area) on record?
Tom Polivka Algonquin
Based on a National Hurricane Center study by Dr. Chris Landsea and updated by Neal Dorst, it appears that the largest tropical cyclone on record was Typhoon Tip which roamed the Northwest Pacific in October 1979. The storm had gale force winds (39 m.p.h. or higher) extending 675 miles out from the eye. The massive storm also holds the record for this planet’s lowest sea level air pressure of 25.69 inches of mercury measured 520 miles northwest of Guam on October 12. The smallest tropical cyclone is thought to be Tropical Storm Marco that packed gale force winds that extended only 12 miles from the storm’s center of circulation as it moved across the far south Gulf of Mexico on Oct. 6-7, 2008.
Chicago’s high temperatures the last week of August have featured a steady string of early-October-like 60s, a level of late-summer chill not encountered here since 1965. After a potentially record-breaking low in the 40s Monday morning, the mercury may eke out a afternoon high of 70 degrees as one of the cloudiest, coolest meteorological summers in recent years comes to an end.
With high pressure firmly entrenched across the Midwest, the city can look forward to a stellar week of weather featuring sunny and warmer days as September begins. Temperatures will steadily climb through the week ahead, finally reaching the 80s by the weekend for the first time since Aug. 19.
No rain is expected in the foreseeable future, giving area soils a chance to dry out after last week’s soaking.
Frost, freeze in Minnesota
A record-low 32 degrees arrived Sunday at International Falls, Minn., while Duluth logged a record 38. Frost advisories were posted for the Upper Midwest again Monday.