Tag Archives: Solar Cycle

WEEKEND WEATHER OUTLOOK

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Fri Morning Update: The latest models have shifted the showers to late Saturday and most of Sunday into Sunday night.  So Saturday is looking like a better day, especially from PHL and northward. I’ll do an updated weekend forecast Friday evening.

The weather for this weekend is again looking unsettled.  There are huge differences between the NAM and GFS models for Saturday with the NAM being much wetter than the GFS.

Basically, there are timing differences with the disturbances that are expected to move along a frontal boundary. The position of the front is also in question.

Perhaps there’s insight in the fact that the new GFS model under development (referred to as the GFS FV3- “Finite Volume Cubed Sphere” ) has a similar forecast for Saturday as the NAM.  By the way, I’ve been looking at the GFS FV3 more and more.

That would mean that Saturday would be the wettest and Sunday would be dry.  Too soon to be sure.

As for the cool weather so far this season, it’s not been a surprise— the nadir in the solar cycle is known for cool weather.  The secondary effects of a solar cycle nadir results in  a lower solar wind  causing more cloudiness.

SO WHAT’S WITH THIS COLD WEATHER?

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People are asking me, what’s with this prolonged winter weather and cold?

One thing not talked about recently is the solar cycle.  We are about to enter a solar minimum.   The solar cycle is a regular, periodic change in sunspot number and the mimimum correlates with reduced total solar irradiance.

The solar cycle repeats ever 10-11 years.

The SORCE PROJECT has been measuring the total solar irradiance since 2003.

SORCE project total solar irradiance
SORCE Project Total Solar Irradiance

The previous solar minimum was in 2009.  The minimum has been shown to have a total solar irradiance that is reduced by about 0.5 -1 watt/m2.  Over the surface of the entire earth, that reduction adds up.

Maybe you’ll recall that the summers of 2009 and 2010 were usually cool?  I think the coming summers of 2018 and 2019 might be similarly cool.   (We’ll find out!)

So if it’s a cool summer, remember, it may be the sunspot cycle.

BTW, Here’s a link from my old blog in 2009 talking about the solar cycle.

Clarification 4-14-18: When I say cooler weather, it doesn’t mean we won’t have heat waves.  But it means that there will be fewer days in the 90s and average temperatures for the months of June July and August may be just below average.