Last Day of Winter Brings Record Cold to Midwest; More Heavy Rain in California

Friday, February 28 marked a fitting final day of meteorological winter over Michigan, which has seen one of its most severe winters in memory during 2013 - 2014. An Arctic blast of cold air poured out of Canada over the Great Lakes, bringing the coldest temperatures ever measured so late in the year to Flint (-16°F), Gaylord (-29°F), and Houghton Lake (-29°F). The coldest spot in the country was in Michigan's Upper Peninsula city of Newberry, where the mercury plunged to a remarkable -41°F. In the Lower Peninsula, the cold spot was Pellston with -33°F--the city's 7th coldest morning on record. In Michigan's Upper Peninsula, the -29°F reading in Marquette was that city's coldest temperature since March 3, 2003, and only the 8th time since record keeping began in 1872 that a temperature of -29° or colder had been observed. Farther to the north, Peawanuck, Ontario hit -47°F. What's remarkable about these records is that they were set without fresh snow on the ground--though there is plenty of horrible-looking old snow around! I still have about 20" on the ground at my place, 30 miles south of Flint. My backyard Davis weather station recorded -18°F Friday morning, which was the 2nd coldest temperature of the winter.

It's been another month of remarkably persistent cold over the Upper Midwest in February, and as of February 27, these cities were on track to have a top-ten coldest February on record:

Chicago (9th coldest)
Green Bay, WI (4th)
Minneapolis, MN (9th)
Kansas City, MO (9th)
Fort Wayne, IN (6th)
Dubuque, IA (3rd)
Peoria, IL (6th)
Rochester, MN (4th)
Madison, WI (10th)
Moline, IL (5th)


Figure 1. Winter Storm Titan coils up off the coast of California in this MODIS image taken on Thursday, February 27, 2014. Image credit: NASA.

A second day of heavy rains for California
A very moist “Pineapple Express” atmospheric river of moisture from the Hawaiian Islands will bring much-needed rains to nearly all of drought-ravaged California Friday and Saturday. As of 8 am PST Friday, Downtown Los Angeles had received 1.17" of rain since midnight. It was the second consecutive day Los Angeles had received over 1" of rain, as 1.05" fell on Thursday. The last time Los Angeles had received more than 2" of rainfall in a 48-hour period was nearly 3 years ago--March 20 - 21, 2011, when 2.58” fell. Today's rains have forced the closure of a 10-mile stretch of the Pacific Coast Highway in Ventura County because of a high likelihood of rock slides in an area made bare by last year's Springs Fire in Camarillo, according to the Associated Press. Mandatory evacuation orders were also issued for about 1,000 homes in the eastern foothill suburbs of Glendora and Azusa, which lie beneath nearly 2,000 acres of steep mountain slopes denuded by the Colby fire in January. NOAA's Storm Prediction Center has placed coastal Southern California in their "Slight Risk" area for severe weather, with a few waterspouts and severe thunderstorms possible. Storm total rain amounts of 2 - 4 inches are expected through Saturday night at lower elevations in Southern California, with 4 -7" in the foothills and 8 - 10" in the mountains.

Two Pacific tropical storms form, boosting the odds of an El Niño
The atmospheric and oceanic conditions in the Equatorial Pacific are ripe for an El Niño event to develop this spring or summer. As detailed in a guest blog post by WSI's Dr. Michael Ventrice on February 21, all that is needed to trigger an El Niño this spring or summer are strong and persistent bursts of westerly winds in the Equatorial Pacific to help push warm water from the Western Pacific Warm Pool eastwards towards South America. Two tropical storms capable of doing just that formed in the Pacific on Friday, boosting the odds that we will see an El Niño event this spring or summer. In the Western Pacific, Tropical Storm Faxai formed Friday morning about 400 miles southeast of Guam. The minimal 40 mph tropical storm is located close to the Equator, at 9°N latitude, which means the the counterclockwise wind circulation around the storm will drive west-to-east winds along the Equator, giving a substantial push to warm waters attempting to slosh eastwards towards South America and start an El Niño event. Faxai is expected to intensify to a Category 1 typhoon by Monday, but is not a threat to any islands. In the South Pacific, Tropical Cyclone Sixteen formed Friday morning near the island of Fiji. This minimal 40 mph tropical storm is moving south-southeast at 10 mph, and is expected to slowly intensify to a strong tropical storm with 70 mph winds by Monday. The clockwise circulation of winds around the storm will also help drive westerly winds near the Equator that will boost the odds of an El Niño event. However, since this storm is farther from the Equator (16°S), it will not have a strong an impact on boosting El Niño odds as Tropical Storm Faxai will.


Figure 2. Visualization of the GPM Core Observatory satellite orbiting the planet Earth. Image credit: Britt Griswold, NASA Goddard.

Important new precipitation measurement satellite launched
A key new NASA satellite called the Global Precipitation Measurement (GPM) Core Observatory was launched into low-Earth orbit, 253 miles above the ground, on Thursday from the Tanegashima Space Center in Japan. NASA confirmed that the satellite successfully deployed its solar arrays and is stable and pointed at the sun. The satellite is a joint venture between NASA and the Japan Aerospace Exploration Agency. The new satellite has the most sophisticated instruments ever launched into space for the study of precipitation, and allows the first-ever space-borne measurements of snow. The satellite carries two instruments to measure rain and snowfall:  the Dual-frequency Precipitation Radar (DPR), and the GPM Microwave Imager (GMI). Together, these two instruments will collect improved observations that will allow scientists to better "see" inside clouds. In particular, they both provide new capabilities for observing smaller particles of rain, ice and snow. The satellite is scheduled to begin providing useful data in May 2014, and will allow worldwide precipitation measurements every three hours. Data from the satellite will be fed into global computer forecast models, and should help improve weather and climate forecasts.

Have a great weekend, everyone, and I'll be back Monday with a new post.

Jeff Masters