One Last Hurdle? 5/4/20
Hello! I hope everyone had a chance to enjoy this well deserved delightful weather weekend! After some early clouds and light showers, Saturday became mainly sunny during the afternoon.
After what seemed like endless weeks of onshore winds, winds turned westerly Saturday, blowing offshore. This time of year, what kind of weather we see, is often dictated as to which way the wind is blowing.
Because it was a land breeze, temperatures responded, with many communities reaching the low 70’s! This drove thousands of people outside, to enjoy the sudden spring weather! It almost goes without saying, after nearly 5 weeks of stay indoors restrictions, many people were more than ready to get some fresh air! Just keep that mask on!
If that wasn’t enough, Sunday was even better! My goodness, can we handle this? After some early morning clouds, sunshine took over for the majority of the day. Westerly winds freshened, but it was a warm wind, with many communities a couple degrees of either side of 80! I believe this was the warmest temperature felt in Boston since October 9th of last year!
I remember something similar happening last year at this time. In fact, I believe it’s been several years in a row now. After a snowless, benign winter, the pattern suddenly changes around the time the spring equinox arrives, leading to a unsettled, cold with occasional bouts of wintry weather.
Very strange weather patters, indeed. These are weather patterns that many folks (including myself) do not care for in the least bit this time of year! What’s the point in getting wintry weather patterns in April and May? Nonetheless, Mother Nature is in complete control…we just have to live through it!
Welcome to May! In astronomical terms, May can be looked at in the calendar year, similar to November. As November is the transmission month to winter, May is the transmission month to summer.
Keeping this in mind, we know we can see late season summer surges during November. Five years ago we were treated to an extremely warm November, with high temperatures feeling more like September.
As we can feel the warmth of summer in November, we can still feel the wrath of winter in May! In a warmer climate, I believe it’s more difficult for this to happen these days.
Yet, Mother Nature is all about balance. Sometimes it happens quick, right before our eyes, an unseasonably warm day is replaced the next day that’s just as cold as it was warm.
In most cases, it’s a longterm balance called our climate. Climatologists like to observe longterm weather trends to see if our climate is changing, or staying the same. This includes looking at all the ups and downs of temperatures, and precipitation patterns.
If they looked back at April 2020, they would see that Boston observed a wetter and colder than normal April. This is in stark contrast to the four straight warmer than normal months we had from December through March.
It did snow in Boston this April. Typically, Boston averages close to 2″ of snow in April. In a unusual lates season storm, close to 1″ of snow fell at Logan Airport early on the 17th, with up to 3″ in surrounding communities. If we do see snow in April, it normally falls within the first 10 days of the month.
Now that we’re in May we no longer have to worry about cold & snow, right? Not necessarily! Coastal areas typically do not have to worry about snowfall in May. However, snowfall can and has occurred across the interior and especially across the higher terrain of New England during May.
It was just a couple years ago that the White Mountains of New England were whacked with up to 3 ft of snow on Mother’s Day!
It has to be a very anomalous event for it to snow along the coast during May. However, it can happen! Need I have to remind many folks in New England with May 9th and 10th, 1977!
In what could possibly be called a once in a lifetime event, a strong nor’easter was captured by a unseasonably cold upper level storm off the coast, resulting in destructive very late season snowstorm for central and eastern Massachusetts.
While Logan Airport only received a half inch of snow (a record to this date), inland areas just away from the the shoreline received significant accumulations.
This includes where I live here in West Roxbury, where an astounding 3 to 4″ of heavy wet snow fell! I remember my neighbor using a broom to knock off the heavy snow from a fully leafed tree!
Further inland, areas as close as Newton saw up to a half a foot of snow! Up to a foot or more fell across the hilly terrain in central Massachusetts with massive power outages and severe tree damage.
This storm still holds the benchmark for many in southern New England to say don’t count snow completely out of the picture along the coast until after May 10th!
As beautiful as the summery feel was this past weekend, winter just doesn’t seem to want to give up this year! The winter that never arrived, now refuses to leave.
The same pattern which brought the cold and wet conditions in April, is going to return with a vengeance this weekend. Ugh!!! It was just last Mother’s Day where some communities reported sleet on Mother’s Day. I was one of these people who did see sleet falling on that cold, rainy day!
Much like in 1977, an extremely cold air mass is heading towards the northeast this weekend. Earlier computer models were actually showing accumulating snowfall for the I95 corridor. This scenario was unrealistic. But it does show you the strength of the cold air mass and atmospheric energy heading our way.
In fact the same storm now looks like it’s going to track closer to the coast, preventing snowfall along the coast. However, latest computer models continue to advertise a mid winterlike storm for the high terrain of western Mass., Vermont, New Hampshire, and western Maine Friday night early Saturday.
This would mean heavy wet snow, strong winds, tree damage, with possible power outages. If your plans take you across the Berkshires of western Massachusetts, central N.H. Including the White Mountains, and the mountainous terrain of western Maine, please be aware that you will encounter difficult and very dangerous driving conditions.
Thereafter, watch for record cold weather for the remainder of the weekend, with highs only in the 30’s and 40”s, and lows in the teens and 20’s. Wow!
Okay. I agree! This may be a bit more than a hurdle. Sounds more like a high jump to me!
Down here is coastal areas, the weather will not be as harsh, but it will not be any resemblence to this past weekend! In fact, there is a strong possibilty of widespread frosts and freezes across southern New England this weekend. I will go over the details shortly in my forecast.
Is this what we can expect for the rest of May? Cold waves, frosts and chances for mountain snows?
Fortunately, I do not believe this will be the case. Long range computer models are showing the coldest air lifting north into Canada as the month progresses.
This would lead to a relaxation to the jet stream, allowing warmer air to flow into New England. Instant summer? Not quite just yet! We still may have to wait until June, which is normal.
No matter what, the daily departure from normals continue to increase every day. No matter how cold an air mass that attempts to invade New England, sun angle and length of day means 50’s and 60’s this time of year. The one exception is this Sunday, when it will be colder.
May typically begins with high temperatures in the low 60’s, ending in the low 70’s at the end of the month. Low temperatures average low 40’s to start, and end up in low 50’s by months end. May can be rainy, averaging a little over 3″ of rain.
However, I must admit the pattern for the rest of May continues to look shaky. The reason is a complicated phenomenon called the MJO, or Madden Julien Oscillation.
In its most simplest explanation, the MJO is observed in the tropical Indian and western Pacific Ocean as an area of rainfall, winds and pressure that traverse the tropic regions around the globe and returns to its initial starting point.*
As of late, the MJO has been stuck in a phase which promotes cold and wet weather here in the northeast. If this happened during the winter, we would of been buried with snowfall!
The big question is if the MJO traverses out of this cold phase, into warmer phase. If it gets stuck, we could be looking at a cooler than average May.
I am thinking after this weekends cold shot, temperatures will return to more seasonable levels, which should leave May near average in the end.
Thereafter, I am still expecting a warmer regime to take over much of New England, leading to another hotter than average summer this year, possibly beginning earlier this year sometime in June. I will have more about this in my summer forecast which will be posted on May 25th!
Now for your weekly outdoor spring activity forecast. I will rate this week a 7 out of 10.
Expect considerable cloudiness this afternoon. Temperatures will be mild, I believe Boston has already reached 70 today. Later this afternoon, there may be a few scattered showers.
After any early scattered showers, expect clearing skies later this evening. It will be cooler, with lows in the 30’s and 40’s in urban areas.
Tuesday will be cooler, with highs mainly in the 50’s to near 60. We may start with bright sunshine, but cold upper levels of the atmosphere will lead to many clouds in the afternoon.
Expect fair and chilly weather Tuesday night. With light winds, temperatures will fall into the 30’s and low 40’s, with areas of frost.
Wednesday should feature sun to start, but clouds will increase during the afternoon. A storm approaching from the southwest may spread rain into the region later Wednesday, Wednesday night into Thursday.
This is similar to a winter situation. If the storm tracks a bit further to the south, we could remain dry across the region. If it tracks closer, a cold rain would envelop the region, with temperatures only in the 40’s.
For the period Friday through Sunday, watch for unusual weather patterns for this time of year. As mentioned above, a strong storm should track close to southern New England into Maine. There will be enough cold air charging down the western side of this storm system for winterlike conditions to develop with snow and cold temperatures. It’s MAY!
After this storm moves north of our region, Saturday will feature windy and chilly weather, with highs in the low 50’s, except 30’s and 40’s up north and higher terrain.
Watch for very cold weather Saturday night, with lows in the 20’s and 30’s regionwide, with widespread frost and freezes. The exception may be right along the immediate coastline.
Sunday will feel more like Thanksgiving than Mother’s Day. There will be some sun, but it will be blustery and cold out. Temperatures may not make it out of the 40’s around Boston, and 30’s across the higher terrain. Cold weather will continue into early next week, then slowly modify.
Make no mistake about it, it may not snow in Boston, but this will be a very noteworthy winter weather event coming up for our region for this time of year!
Well, that’s about it for now! In next week’s blog, I will be discussing in more detail my thoughts for the summer outlook. I will also see if and when our spring pattern will stabilize. In the meantime, get your sneakers on to be prepared for whatever hurdle Mother Nature has in store for us!
Thanks for reading!
Pete
*Some information derived from NOAA