Father's Day, Solstice And Unusual Pattern
HAPPY FATHER'S DAY! It is going to be a soggy one primarily this morning with only a few showers early afternoon leading to some breaks of sunshine in a very humid air mass. Father's Day is occurring on the latest possible June day this year and coincident with the official start of astronomical summer known as the summer solstice. This happens at 12:38 pm.
It is the longest day of the year with direct daylight amounting to 15 hours and 20 minutes which is 6 hours and 18 minutes longer than on the Winter Solstice on December 22! Despite that, the earliest sunrise occurred a week ago on June 14 and the latest sunset occurs on June 27. The sun at noon will be 70.7 degrees above the horizon versus 23.8 degrees on the Winter Solstice! The heat energy received at the surface at noon is 33% greater in June than it is in December! Solstice literally means sol or sun and stice/sistere means to stand still. This solstice is an instant in time when the North Pole points more directly toward the Sun than in any other time of the year.
The heaviest rain in the form of occasional downpours will occur between about 7 and 11am. Scattered bolts of lightning cannot be ruled out and the wind, for the most part, will be rather light although it could be gusty from the South over Cape Cod. With breaks of sunshine developing this afternoon, the temperatures should climb to the middle 70s at least.
An active pattern is setting up this week with several bundles of energy traveling along in the jet stream. First off, it appears that the stage may be primed for an outbreak of severe weather on Tuesday. A strong cold front will be approaching the area with upper level support and strong wind fields thanks to an intensifying storm transiting over the St. Lawrence River Valley. A sizeable amount of potential wind shear is worrisome so be ready to keep an eye on the sky!
Beyond that, the next upper level impulse digs in to potentially create an anomalous storm of rain and gusty east-northeasterly winds on Friday. It is definitely not etched in stone yet but it is apparent that either rain or another outbreak of severe storms is possible if the storm center shifts farther to the north into New England. It could be another June aberration like June 15 when the afternoon temperatures were only in the middle to upper 50s! And to make matters even worse, that scenario could be duplicated a week from today!
It's all about the jet stream and the pattern depicted in the map to the left for next Saturday reveals a strong trough of low pressure diving into the Midwest having popped over the strong ridge in the western states. This is quite extraordinary for late June!
Consequently, these steering currents will never deliver any hot weather so it is possible that Boston will not get its first day at 90 or higher until sometime perhaps in early July similar to last year when it hit 91 on July 2! That will, of course, disappoint some and thrill others. On average, the first day of 90 degrees for the city happens on June 8. Now, there is a very slight chance that Boston may receive a 90 tomorrow or Tuesday but that is a long shot. A 90 on Tuesday would not be a good thing because that would mean the area would be in a hot and steamy air mass with parameters to trigger nasty storms with a cold front closing in. We shall see but as you can now see, there are many features to follow in the next 1-2 weeks!
By the way, despite this bizarre jet stream pattern coming up, I am still anticipating the mean temperature for July and August to be slightly above average. With that said, I am not expecting long-lasting stretches of excessive heat and humidity but there will be some of those days in both months. Right now, it appears if the next week verifies with the above prediction, the mean temperature for June will end up a bit below average. We shall see.
Make it a great week!
Maps used in this blog are courtesy of WBZ , WSI & WeatherBell.
