The Pieces to the Puzzle Called Sandy

Posted by Chris Lambert

The forecast challenge for early next week continues with the path of Sandy and any impacts that’ll have on our weather here in New England.  

The 5:00 AM update from the National Hurricane Center has Sandy as a tropical storm with winds of 70mph.  Sandy likely becomes a hurricane as it approaches Jamaica later today and maintains hurricane strength as it approaches Cuba later tonight.   Sandy then goes through the Bahamas and emerges north of the Bahamas by Friday night. 

Notice the 5-day track? There is a hard turn NE by Saturday and almost all of the time, that turn is the point of no return, where storms head out to sea and never look back.   Especially in the Fall when a fast moving, west-to-east jet stream accelerates storms across the opens waters of the Atlantic. 

Therein lies the potential problem.  The jet stream may, indeed, not be west to east this time.  There are a few computer models that insist that a massive area of high pressure builds in south of Greenland and just east of Labrador, blocking the pattern.  It’s what we meteorologist refer to as a negatively indexed North Atlantic Oscillation (-NAO).  That often coincides with the jet stream upstream (across the eastern U.S.) buckling.  If a piece of energy can rotate in around that buckling jet stream at the right time across the eastern U.S., Sandy could actually phase with that upper-level energy and move back toward the coast.  If this were to occur, Sandy, which transitions into a massive Nor’easter, would provide an expanding shield of powerful winds and rain, bring in damaging gusts, flooding rains and coastal flooding over parts of the mid-Atlantic and/or New England anywhere in the Sunday-Tuesday timeframe.  Highest impact areas would depend on track.

Obviously, the stakes are high, but unfortunately, so is the margin of error.  In the grand scheme of things, we’re trying to have a system in the Caribbean phase with upper-level energy which is currently way out in the Pacific, based on what happens to pressure patterns south of Greenland. If it sounds complicated, that’s because it is, and that is the reason why computer models are having a tough time handling it.  Climatology tells us this is a storm for the fishes, which is certainly still a strong possibility, but given the fact that the NAO is so strongly negative, a plausible argument can be made for this one heading back to the coast.   There have been October storms that haven’t curved out to sea.  Hazel in 1954 is one, and the Gale of 1878 is another.

I’m not leaning one way or the other at this point giving how far out we are.  My advice for the next couple of days is to keep checking up on this, as new model data comes out and the pieces to the puzzle get closer together in the atmosphere, the picture the puzzle leads to will become clearer. The forecast challenge for early next week continues with the path of Sandy and any impacts that’ll have on our weather here in New England.  

Pulling The Fade

Posted by Chris Lambert

Our fun in the sun ends this afternoon as morning sunshine fades behind thickening clouds.  As those clouds increase, a few showers break out this afternoon from west to east, with the highest chance for rain late afternoon and this evening.  Most of the showers are light, especially the early afternoon ones, but a heavier shower or two is possible near day's end and early this evening.  Highs reach the mid to upper 60s around noon, then fall back to near 60 mid to late afternoon thanks to scattered showers.  These showers are brought to us by a warm front.

Back and Forth

Posted by Chris Lambert

Quite a few clouds in the sky at times this afternoon, but the atmosphere lacked ample moisture to produce showers, so we made out just fine with temps near 70.  Even the coast made it well into the 60s before the onshore wind knocked temps back.

Pretty Good Weekend Overall

Posted by Chris Lambert

Sure, it's a cool start with many of the suburbs down into the upper 30s and lower 40s, but we'll warm up quickly through the day as that sun helps us out.

Strong Finish

Posted by Chris Lambert

An overall cooler day, but also a great end to the workweek as highs neared 70, low humidity continued and plenty of sunshine dominated the skies.  Now all we need is this to continue through the weekend right?