Ask the Weather Team
Where's YOUR winter forecast?
Pete Bouchard says: Although many other meteorologists like to give their impression of the winter forecast, I don't. From what I've seen, there's no proven science to a seasonal forecast whatsoever. Although many people like to hang their hats on what El Nino or La Nina may or may not do to New England, the fact of the matter is the signal from either is weak here in New England, and we've had winters (and springs) that are both warm (rainy) and cold (snowy). El Nino & La Nina are variations in the Southern (Pacific) Oscillation. Our winter weather mostly depends on the North Atlantic Oscillation. So far, no one has been able to predict with accuracy what that will do in ANY season. So to go out on a limb and predict a seasonal forecast amounts to nothing more than a guess...or in the case for snow-loving meteorologists, "wish"casting.
We all know that recently (within the past decade) all seasons have seen dramatic temperature and precipitation swings. It's nothing to see records shattered - sometimes within a week of each other! I think the bigger question is, why is this happening? Is this the new norm? Ironically, the answer may be more predictable than a seasonal forecast.
Pete
Chris from -NA- asks: What makes a storm stall like the blizzard of 1978?
Jeremy Reiner says: Hi Chris-
Great question! Our storms are pushed along by the jet stream and normally that jet stream (or storm track) is like a garden hose stretched out. Sometimes though the jet stream can develop dips (like a garden hose). When this happens, these storm get 'stuck' in one general location for several days. This is what happened during the Blizzard of '78. Here's a picture of a 'blocking' jet stream:
When that pattern happens, typically the east coast of the United States is prone to slow-moving snowstorms....like we saw in the Blizzard of '78 AND like Washington D.C. saw twice last winter.
Hope this helps---thanks for watching 7news
Sincerely,
Jeremy Reiner
Maeve asks: Why is it that some hailstones are really big, and some are small?
Pete Bouchard says: Hail size is dependant on the updraft - or upwardly moving air - inside a thunderstorm. Simply put, the stronger the wind, the larger the hail. Strong winds moving upward can lift and support larger hailstones than thunderstorms with weaker - or light - winds. Temperatures within the cloud matter too. The lower the freezing level in a cloud, the more likely that it will produce hail. Typically, if the freezing level is below 11,000 feet, thunderstorms are more likely to contain hail.
Troy from Metrowest asks: Drought and Leaves Turning.
Jeremy Reiner says:
Hi Troy-It sure is....many of the trees around where I live are also changing and dropping!....I used to work in Charlotte, NC and about 10 years ago we had a drought that caused the trees to change color and even drop in mid August---much like we are seeing here.An amazing turn-around compared to the wet summer we had last year.Thanks for watching 7news!-JeremySteven asks: What is a microburst, and how do they form?
Pete Bouchard says: Downbursts, or downward moving winds that rush out of the bottom of a thunderstorm, can be classified as microbursts or macrobursts depending on areal extent of the damage they cause.
All thunderstorms operate like a vacuum cleaner. There's and inlet and an exhaust. The air flowing in sucks up moisture and feeds the storm throughout its life cycle. As the storm matures, it drops rain. This rain cools the air it's falling through, causing it to drop toward the ground (think back to the "warm air rises, cool air sinks" theory). This downward flowing air is the exhaust or downburst. (It's also what gives that refreshingly cool feel during the storm.) Sometimes these winds can reach speeds equivalent to that of hurricanes or tornadoes. The strongest downbursts in recent memory have been clocked at 175 mph at Morehead City, NC! Locally, we've seen downbursts reach speeds of 104 mph in both Worcester on May 31, 1998 and Whitman on May 21, 1996!!
If the damage area extends 2.5 miles or less, it's a microburst. If it's 2.5 miles or more, it's a macroburst. We had a macroburst from a thunderstorm on Sunday June 6th, that traveled all the way from Framingham to Revere.
