Summer 2017 Forecast

I’m going to make this version of the summer outlook fairly quick, simple, and to the point. Our drought now essentially behind us, and the pattern having been wet, it’s obvious we are not going into summer 2017 the way we did just a year ago. The pattern in the spring was wet, with a cold March, a milder April, and a very cool May (the coolest since 2005 and the first below normal May in many parts of the region since 2008). What follows is a short summary of what I expect for the summer. I have observed forecasts from colleagues, NOAA, and other professionals and I will say that I’m in general agreement with most of them.

SUMMER 2017 OVERVIEW
A pattern of blocking at high latitudes has resulted in a pattern of frequently cool, often cloudy, and occasionally wet weather for New England during the last several weeks, and this general idea will continue into the early and mid part of June, though as climatology dictates, we continue to warm slowly as we advance the calendar so the direct impact, while less, will still be noticeable when compared to daily normal values, especially for temperature. As we move into late June, we should see a shift of the pattern as blocking weakens and dissipates, and a more zonal flow takes over. This will allow more episodes of westerly flow and more seasonable warmth with occasional spikes of heat alternating with brief cool-downs as air masses change with passing systems on a more progressive jet stream. Heading into the heart of summer, provided a forecast El Nino is slow to develop, and I suspect it will be, we should see an occasional Bermuda High setup as high pressure in the western Atlantic occasionally retrogrades (backs westward) toward the East Coast. During these times we will see our higher humidity, some heat, and episodic showers/thunderstorms. The shower activity this summer will be more prolific than that of last summer, keeping overall precipitation amounts near to above normal and preventing a slip back into drought. This, along with what ends up being a warmer middle and end, will skew temperatures to near to above normal. So the theme of summer 2017, after its cool start, will be warm and wet.

JUNE SPECIFICS
Current pattern of blocking and frequent troughing in the Northeast continues through mid month with precipitation above normal and temperatures below normal. Pattern breaks down around the summer solstice and the last third of the month will be warmer and drier with passing systems in a more progressive jet stream flow causing brief shower/thunderstorm threats.
Temperature: Below normal.
Precipitation: Above normal.

JULY SPECIFICS
The first half of the month should feature the pattern that is established during the latter third of June. The second half of the month will feature an alternating between the early July pattern and a more humid and showery Bermuda High pattern. Though this type of pattern does not typically produce all day rains, we’d have to be on the lookout for some tropical moisture feeds that could provide days with frequent showers/thunderstorms.
Temperature: Near to above normal.
Precipitation: Near to above normal.

AUGUST SPECIFICS
Take the pattern of the second half of July and continue it for August, but with more emphasis on Bermuda High and less so on westerly flow and progressive jet stream. Should be a warm and humid month with episodic showers and thunderstorms. Though we cannot predict very far in advance whether or not a tropical storm or hurricane will threaten the region, or any part of the US coast, we can say that a Bermuda High pattern can leave the East Coast vulnerable, should a storm form and be in the right position to get around the western side of such a high pressure area.
Temperature: Above normal.
Precipitation: Near to above normal.

14 thoughts on “Summer 2017 Forecast”

  1. Thank you, TK. Excellent discussion.

    July….”The second half of the month will feature an alternating between this pattern and a more humid and showery Bermuda High pattern.”

    That’s it. My vacation is ruined. Ruined I tell you. I am debating whether to cancel now 😉

      1. Hehehe…I know that you know I was kidding. I’m actually a fan of all kinds of weather at the beach also…..especially storms that produce huge seas

  2. When u say “this” pattern, I assume you mean the early July pattern and not the one we’re in now.

    1. I mean the early July pattern. I’ll edit that and clarify it as soon as the server is reset and I can get back on my admin account…

  3. Thank you for the excellent discussion, TK.

    As the cool pattern continues, snow in the peaks of the Presidential Range (above 5000 feet) is likely through next week. Not seeing any major storms up there, but the potential exists for accumulating snows the first week of June, from Lincoln to Washington to Madison.

  4. Thanks, TK! SUPER bright lightning and ginormously loud thunder just happened in Chelmsford. My cats are very frightened!

  5. Sounds like a fun meteorological summer with the potential for more frequent boomers and perhaps even a tropical system of sorts to keep an “eye” on. Thanks TK! 😀

  6. Not to look too far ahead, but I would be curious if the warm, wet pattern continues into much of the fall. September is peak hurricane season around here.

    Thanks as always TK! 😀

    At least no water bans this summer and I am looking forward to some delicious peaches come August, which was ruined last season due to drought. 🙂

  7. Pretty much agree with all that the brilliant TK has forecasted. My added thoughts would be to delay pattern change by 7-10 days more towards late June. August ends up much above normal and maybe a bit drier as thunderstorm activity is more prevalent just north of SNE.

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