It’s hard to believe we have turned the page, and we’re now into the last month of 2012! December 1st may just be a date to the average person, but for weather geeks, it’s the start of “Meteorological Winter.” Meteorologists break down the seasons according to temperature, and the coldest months of winter are found in December, January and February. Check out the list below, and you’ll see the date differences between Meteorological and Astronomical seasons.
Astronomically speaking(and as the general public,) we will celebrate the winter solstice on Friday, December 21 at 6:12 A.M. EST. This is the date in which the Sun’s rays hit the Earth at their southernmost point. In the northern hemisphere, we experience our shortest daylight hours at this time, and the Arctic Circle is thrust into 24 hours of darkness. The southern hemisphere is basking in more daylight hours, and the Antarctic Circle has 24 straight hours of light.
December is coming in more like summer across the southern and central plains, as temperatures soar 15 to 30-degrees above average. In some communities, records are already being broken as of 1 PM CST. North Little Rock, Arkansas is up to 73, breaking the old record of 71 set in 1982. Other record highs are expected, definitely bucking the start of
We’re running in a completely opposite direction in the western mountains. Heavy snow continues in parts of the Rockies and Cascades, with some areas picking up 2 to 4 FEET. Winter storm watches and warnings pepper our maps through Monday, with a series of storms still in the Pacific set to batter the western U.S. right through the end of next week.
In the lower elevations, rain totals could exceed a foot in a few isolated locations, especially in northern California. Parts of Washington and Oregon could easily dump between 1 and 6 inches of rain from rain gauges as well.
By the way, for those of you who may be heading to the Minnesota Vikings-Green Bay Packers football game at Lambeau Field in Green Bay, Wisconsin Sunday, keep your eye out for me! I’ll be the crazy fan cheering for the Vikings, IN A PACKER JERSEY! Yes, lost a bet with my Dad last year, and will pay for it in crowd jeers. Be sure to say hi! Oh, and dress for the upper 40s…
Meteorologist Bryan Karrick (twitter: @bkarrickWNTV)
Preliminary November Climate Summary. Here’s a snippet from Dr. Mark Seeley’s always-informative WeatherTalk Newsletter: “Most observers reported average monthly temperatures for November that ranged from 2 to 4 degrees F warmer than normal, with the larger positive departures in temperatures coming in southern counties. Extremes for the month ranged from -11 degrees F at Fosston (Polk County) on the 26th to 75 degrees F on the 10th at Rochester, Amboy, and Winnebago. The warm day on the 10th also brought extremely rare November tornadoes to the state. These storms were reported from Burnsville, Eagan, Mendota Heights and Mahtomedi, and were the 2nd latest autumn tornadoes in Minnesota history (there was a tornado near Maple Plain back on November 16, 1931).”
Negative Trend For NAO? The NAO (North Atlantic Oscillation) Index is a tip-off of weather to come, 1-2 weeks out. Strongly positive NAO’s often correlate with quiet weather, strongly negative phases of NAO correspond to more dips and bulges in the jet stream, a greater potential for storms. We’re in a drought, but maybe we’ll be brushed by a few storms come mid-December. We’re due. Graph above: NOAA.
2 Week Extended Outlook. The GFS forecast map above is valid December 16, showing the “540 line”, the approximate location of the rain-snow line, pushing into southern Minnesota, another major storm thrashing the west coast. Highs reach the 20s and 30s from December 9 into December 16, fairly close to average for December. No frigid air is in sight – no major storms are brewing either, looking out 2 weeks or so. I keep waiting for a break in the pattern – don’t see it yet.
Friday Night Satellite. The first frontal boundary is clearly visible from Las Vegas to Boise, with partial clearing over the west coast. Mainly dry conditions should hold much of the day Saturday, but already the next (severe) frontal boundary is showing up in the Pacific, scheduled to arrive on Sunday. Meteorologists call this “The Pineapple Express”, a treadmill of unusually wet systems lined up all the way from Hawaii to the West Coast of the USA. Satellite: Naval Research Lab.
1-2 Months’ Worth of Rain Has Already Fallen. The map above shows Doppler-estimated rainfall amounts from Thursday and Friday; a huge area has already picked up more than 2” of rain, with pockets of 6-10” of rain from Mendocino north to Medford, Oregon. Widespread flooding and mudslides have been reported over northern California. The ground is saturated – Sunday’s rain will trigger more extreme flooding and additional road closures and overflowing rivers. El Nino may be priming the pump, increasing the potential for excessive rainfall and snowfall amounts.
Additional Predicted Rain. The high-resolution model above shows additional rain expected by Monday evening – most of it falling Sunday and Sunday night as the next front sweeps from northwest to southeast across the region. Another 6-8” of rain (and heavy mountain snow) is likely over higher terrain east of Redding and Chico, with some 2-4” rainfall amounts for the coastal range near San Francisco and Oakland. Los Angeles will see minimal amounts, under .5” of rain expected. Then again, it doesn’t take much rain to turn L.A. freeways into one vast parking lot. Map: WSI.
Alerts Broadcaster Models. Our weather simulations show a broad area receiving at least 3” of additional rain Sunday, with upwards of 10” amounts for the Coastal Range and as much as 10-15” for the northern Sierra Nevada range of northern California. This may translate into an additional 50-100” of snow with a significant avalanche risk north of Lake Tahoe.
Megastorms Could Drown Massive Portions Of California. “Atmospheric Rivers”? We’re seeing new phenomena on our weather maps, things that can’t be explained away as “normal weather”. Here’s an excerpt of a timely article at Scientific American: “Geologic evidence shows that truly massive floods, caused by rainfall alone, have occurred in California about every 200 years. The most recent was in 1861, and it bankrupted the state. Such floods were most likely caused by atmospheric rivers: narrow bands of water vapor about a mile above the ocean that extend for thousands of miles. Much smaller forms of these rivers regularly hit California, as well as the western coasts of other countries. Scientists who created a simulated megastorm, called ARkStorm, that was patterned after the 1861 flood but was less severe, found that such a torrent could force more than a million people to evacuate and cause $400 billion in losses if it happened in California today.…”
Graphic credit above: “A 43-day atmospheric-river storm in 1861 turned California’s Central Valley region into an inland sea, simulated here on a current-day map.” Image: Don Foley
19 named tropical storms and hurricanes in 2012 in the Atlantic basin, 3rd most since 1851. Details from AP and The Washington Post.
Rebuilding Cities After Sandy: Three Keys To Climate Resilience. Here’s an excerpt of a story from Huffington Post:
1) Build Green as Well as Gray
“As we saw from Hurricane Sandy and other destructive, recent storms, cities from New York to Miami to Houston need to develop infrastructure that reduces the vulnerability of homes, commerce, and services.
This does not mean walling-in every coastal community with huge barriers or dikes. Where cities meet shorelines, “green infrastructure” can often meet the same need. For example, Maryland’s state government is buying up wetlands and marshes to provide buffers against future storm surge. And in New Jersey, the restoration of South Cape May Meadows provided a natural seafront barrier that helped the area fare much better than others when Sandy hit…”
Photo credit: “Parts of the brick walkway of Liberty Island that were damaged in Superstorm Sandy were shown during a tour, in New York, Friday, Nov. 30, 2012. Tourists in New York will miss out for a while on one of the hallmarks of a visit to New York, seeing the Statue of Liberty up close. Though the statue itself survived Superstorm Sandy intact, damage to buildings and Liberty Island’s power and heating systems means the island will remain closed for now, and authorities don’t have an estimate on when it will reopen.” (AP Photo/Richard Drew)
Welcome to the WeatherNation blog. Every day I sift through hundreds of stories, maps, graphics and meteorological web sites, trying to capture some of the most interesting weather nuggets, the stories behind the forecast. I’ll link to stories and share some of the web sites I use. I’m still passionate about the weather, have been ever since Tropical Storm Agnes flooded my home in Lancaster, PA in 1972. I’ve started 5 weather-related companies. “EarthWatch” created the world’s first 3-D weather graphics for TV stations – Steven Spielberg used our software in “Jurassic Park” and “Twister”. My last company, “Digital Cyclone”, personalized weather for cell phones. “My-Cast” was launched in 2001 and is still going strong on iPhone, Android and Blackberry. I sold DCI to Garmin in 2007 so I could focus on my latest venture: WeatherNation. I also write a daily weather column for The Star Tribune startribune.com/weather And if you’re on Twitter, you’ll find me @pdouglasweather