Expect unusual East Coast cold and West Coast heat to "remain in place through most of the remainder of March."
The nation is only two weeks out of meteorological winter and already some places are sizzling like bacon grease. Exhibit A: The San Francisco Bay Area, which has been clamped in a sticky armpit of warmth. On Wednesday, Oakland hit a record high for that date of 78 degrees. Exhibit B: SoCal, where temperatures this Sunday are predicted to shoot up to around 90, or 20 degrees above average for this time of year in downtown Los Angeles.
The incoming rush of oppressive air has prompted the L.A.-area National Weather Service to issue this "special" bulletin:
THE UNSEASONABLY WARM TEMPERATURES WILL APPROACH OR ECLIPSE RECORD LEVELS ACROSS THE AREA FOR THIS TIME OF YEAR. PERSONS PLANNING OUTDOOR ACTIVITIES THIS WEEKEND SHOULD PLAN ACCORDINGLY. SCHEDULE ACTIVITIES FOR THE COOLER PARTS OF THE DAY. WHEN EXERCISING...STAY HYDRATED BY DRINKING PLENTY OF WATER OR OTHER NON-ALCOHOLIC FLUIDS. IF OUTSIDE DURING THE HOTTEST PART OF THE DAY...STAY IN SHADE AND WEAR LIGHTWEIGHT CLOTHING. IF POSSIBLE...GO INDOORS TO AN AIR CONDITIONED LOCATION.
Meanwhile, the eastern half of America can't seem to pry its rigid, frost-bit extremities out of the freezer. It's like the country has been split in two by a massive weather wall, with the West baking in the open sun (it was actually too warm to sit on metal furniture in Oakland yesterday) and people in the East miserable and shivering despite being swaddled in the clothing equivalent of a grizzly-bear pelt (stay on your side, East Coast – we don't want you tracking the cold over here!).
What's to blame for this stark divide in the hotness haves and have-nots? Shake your mittens at a strong, long-lasting weather pattern that has the jet stream dipping low in the East and curling high in the West. You can see how the jet is majorly housing the Atlantic region in this satellite image overlaid with wind arrows:
Seeing as how the weather pattern has been dumping on the East for most of the winter, it isn't going to just up and leave now. Expect it to "remain in place through most of the remainder of March," says Jeff Masters over at the Weather Underground, adding this not-at-all-bitter aside:
The latest 16-day forecast from the GFS model predicts a continuation of the dominant ridge over the Western U.S. and trough over the Midwest and Eastern U.S. that we've all grown very, very, very tired of (said Dr. Masters, after shoveling the latest installment of 6.5" of concrete-like snow of this winter's 90.7 inches that have fallen in the Detroit area--second only to the 93.6" that fell in the winter of 1880 - 1881.) Detroit has now had over 1" of snow on the ground for 72 consecutive days, and will easily break the record of 74 straight days, set during the notorious winter of 1978.
Equally tired of this persistent pattern must be the people of California, who are emerging from their warmest winter on record. Drought continues to stalk the land, drying out vast reservoirs. This February climate summary from NOAA points out the unusual rash of heat in California and Alaska, and also nicely summarizes the East's unending encounter with icy grief: