While Winter Storm Vicky (Vulcan) will be the big news this week in the United States, and Europe basks in a heat wave, significant changes are occurring at the top and middle of the globe that will affect weather in the Northern Hemisphere.
El Niño Alert
The Climate Prediction Center (CPC) has issued an El Niño Watch. Conditions continue to be neutral and are expected to stay that way through spring.
Some minor changes have taken place in the eastern Pacific, and the El Niño, which is overdue, could develop during summer or fall. The CPC puts the odds at 50%.
Effects of El Niño
An El Niño is normally accompanied by wetter than normal conditions in the southwest United States, and some relief from the drought is likely if the El Niño forms.
In the Atlantic, the El Niño frequently suppresses hurricane activity by increasing the mid-level west winds.
Changes at the North Pole
At the North Pole, analyses of the heights of the 500 millibar level show that they are returning to normal after being above normal all winter. The high pressure at all levels at the pole has squeezed the polar vortex southward, resulting in the harsh winter over the United States. Lower pressures at the pole will lead to a more normal jet stream pattern.
The forecast polar pattern for March 15 shows that the trough remains over the eastern United States.
The ridge that has brought unseasonably warm weather to Europe persists. However, the positive height anomaly at the pole has disappeared.
Longer range forecasts show the jet stream flattening, with a return to more seasonable weather in the United States and Europe.
Tropical Activity Near Australia
A tropical low pressure center that has meandered towards Australia for several days became tropical cyclone Hadi on Monday. It is the equivalent of a category one hurricane. The forecast calls for Hadi to move out to sea and weaken.
This season, eight tropical cyclones have formed in waters near Australia and two have reached category three status.
The Latest on Winter Storm Vicky
The band of six inches of snow will stretch across northern Illinois and Indiana today and tonight, but the most significant effects of Vicky will be on Wednesday and Wednesday night as She moves into New York and New England.
Over a foot of snow will fall in upstate New York and maybe up to two feet in northern New England. Boston and New York will escape with no snow or just a dusting, as the bulk of the precipitation in southern New York and southern New England falls as rain.
As Decoded Science reported yesterday, Vicky will develop a gale center, probably a little sooner than we previously thought. Winds up to 50 miles per hour could affect the path of heavy snow from New York through New England, as well as coastal waters. The National Weather Service has issued gale warnings for the Gulf of Maine.
Hot Off The Press
The latest computer forecast at 8 a.m. Tuesday shows a second storm following Vicky, and moving through southern Canada Friday and Saturday. The areas affected by Vicky will be on the warm side and snow should be confined to Canada.
Looking farther ahead, after seven days the jet stream flow flattens somewhat, which should give the eastern U.S. a respite from storms, and could even bring a sprinkle to southern California.