El Nino – Weather 101 with Al Kaprielian

By: Al Kaprielian

This winter continues to differ greatly from last winter with warmer temperatures and less snow.

This winter is an El Nino winter where the cold artic air has a difficult time staying for a long period of time. El Nino occurs when the South Pacific Ocean is warmer than normal. El Nino effects the jet stream and it causes more of a trough over the western US, and more of a ridge (high pressure) over the western US. We have seen this with the upper level ridge of high pressure in the Atlantic Ocean that keeps on re-building.

This has caused a much warmer winter for New England. We have still occasionally seen some ocean storms; however, many storms this winter have tracked to the north & west of New England. When low pressure tracks to the north & west of New England, we are on the east, or warmer side of the low-pressure system. This causes mainly rain to occur.

We have also seen strong winds aloft with these westward moving low-pressure systems. An example was on Wednesday, February 24 when strong winds aloft mixed down to the ground.
This occurred more over Massachusetts, Connecticut, and Rhode Island. Blue Hills in Milton, MA had a wind gust to 83 miles per hour. This is greater than hurricane force, which starts at 74 miles per hour. In New Hampshire, winds were not quite as strong during that week. The reason was that the cooler air at ground level took longer to scour out. This made it more difficult for the winds aloft to mixt down to the ground. What can we expect for March? We have seen some big snowstorms in March and also seen some very warm days.

Any snow that does fall in March does not last long with the sun getting higher in the sky and the days continuing to get longer. Meteorological winter, which is December, January, and February is over, however, it still continues astronomically until mid-March. We will take another look at the weather pattern in next month’s article. Spring is not too far away.