First mid-90s heat wave of summer 2012

Happy Father's Day to all of you dads out there!  It's been said that being a father is easy, being a dad is something entirely different... I'm grateful and blessed to get to work every day at being a great DAD!

The weather this week is going to cause everyone - dads and all - to want to leave the mower in the garage and find the nearest swimming pool!  Though we've had a taste of summer already this year, this will be the first full week of summer-like conditions for 2012, just in time for the summer solstice, which occurs Wednesday, June 20, at 6:09pm CDT.  The first full day of summer (on Thursday) also happens to coincide with the first day of 2012 that MWN is forecasting mid 90s for high temperatures!

Summer solstice

The summer solstice is the point in time when the Earth's axis is most inclined toward the sun, yielding the longest day of the year for the Northern Hemisphere, thus the beginning of our summer. It is also the day when the apparent position of the sun is the highest in the sky for those in the Northern Hemisphere. The graphic below shows the illumination of the Earth at the summer solstice. Notice that the areas around the Arctic circle get light all day as the Earth rotates, while those areas near the south pole are in darkness all day.

Hot weather this week

The reason for this week's hot temperatures can be traced primarily to the mid and upper levels of the atmosphere, where a massive ridge of high pressure will reside over much of the eastern half of the U.S. with the main jet stream near the U.S./Canadian border. The graphic below shows the jet stream in pinks and reds well to the north and high pressure dominating the eastern U.S. on Tuesday evening.

Jet stream-level picture of the atmosphere on Tuesday evening.
Broad high pressure dominates the eastern half of the nation.

The recent dry conditions won't help the heat either, as the moderate drought will mean the ground, and therefore the air directly above it, can heat even more quickly than if the ground were more moist - perhaps adding a couple of degrees to the high temperatures over what this weather pattern would typically produce given more "normal" rainfall leading up to now.

MWN is expecting highs to be in the lower 90s for the first half of the week, then mid 90s for the end of the week and into the weekend. Rain chances are very isolated until at least next weekend and humidity values will likely mean our first 100-degree heat indices of the summer by next weekend as well!

Heat and drought also tend to build on themselves, meaning once they begin, it takes more rain or a larger "push" of cold air to break the cycle. Hopefully it doesn't mean a long, dry, hot summer ahead!

This heat wave will be felt throughout the eastern U.S. under the influence of the upper level ridge. Check out the nationwide high temperatures forecast for Wednesday below.

High temperatures forecast for Wednesday by the NWS. Heat will dominate the eastern and southern U.S.

How about you? Do you prefer the heat and "dog days" of summer or are you a cool weather fan?

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String of above normal temps could end as summer begins!

Since May 28, the Memphis airport has had only one day in which the high did not reach 90 degrees (it was only 89 last Friday). In that stretch, the average high has been 94.5 degrees and the average low 73.5 degrees, for an average temperature of 84 (or about 7 degrees above normal).  And it's not even summer yet!

The summer solstice occurs tomorrow, June 21, at 12:16pm CDT, marking the longest day of the year and the "official start" of summer (though meteorological summer began June 1). It's hard to believe that with an average high of 94 degrees over the past 3+ weeks that summer hasn't even started, but it's true.  The good news in all this is that it looks like summer may start with a return to more "normal" temperatures, which are a high of 90 and a low of 70.  A slow-moving cold front will moves towards the Mid-South Tuesday night then stall over the area into the weekend. With more cloud cover and higher  rain chances, especially Wednesday, we should see highs back into the 80s for a few days this week.  Plus, with the front hanging around into the weekend, we'll be expecting some "summertime" thunderstorms Thursday through Sunday.  Severe chances are not high, but we could see some storms pose a wind or hail risk on Wednesday before the front begins to weaken as it loses some momentum.

Visit the MWN Forecast for complete details on this week's rain chances and temperature trends.

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For weather information for Memphis and the Mid-South, where and when you need it, visit MemphisWeather.net on the web, m.memphisweather.net on your mobile phone, download our iPhone or Android apps, or visit us on Facebook or Twitter.

Out of this world! Astronomical adventures of December 21, 2010

A couple of events in the world of astronomy will line up on Tuesday for the first time in 372 years and won't happen again for another 84 years. Most people probably know of both, but may not have put two and two together yet to realize they happen on the same day. The most obvious is the occurrence of the winter solstice, or what we commonly call the first day of winter. The other is a total lunar eclipse, which will be visible to all North Americans given the right weather conditions.

Starting with the eclipse... a lunar eclipse occurs when the Earth lines up directly between the sun and the moon, causing the Earth's shadow to be thrown over the moon. A total lunar eclipse is when the entirety of the moon is within the Earth's shadow and is less common than a partial eclipse. The next total lunar eclipse visible in the United States is not for another 3+ year - April 15, 2014. When the eclipse occurs, the moon will turn grey, then an orangish-red color as the eclipse becomes total, before returning to it's normal state.

Graphic courtesy Mr. Eclipse. Click for larger image.

In order to view the eclipse, you'd have to get up in the middle of the night (early Tuesday morning). The partial phase begins at 12:33 am CST. The total eclipse lasts from 1:41 am-2:53 am, or a lengthy 72 minutes, with "mid-eclipse" occurring at 2:17 am. The eclipse will be complete by 4:01 am. The graphic above shows these times as well (subtract one hour to convert from Eastern Standard Time). The only problem with Memphis viewing conditions will be the weather. Unfortunately, as of this writing (Sunday afternoon), MemphisWeather.net is forecasting overcast conditions with a chance of light rain during that time frame so we may have to settle for pictures or video from other parts of the country, or you can check out a cool animation and see what you might miss at ShadowandSubstance.com. You can also see a series of photos taken of a lunar eclipse several years ago by MemphisWeather.net here. If weather conditions improve, we'll be sure to let you know!

The other event, the winter solstice (Wikipedia), is the point in time when the Earth's axis is most inclined away the sun, yielding the shortest day of the year for the Northern Hemisphere and the beginning of our winter. It is also the day when the apparent position of the sun is the lowest in the sky for those in the Northern Hemisphere. Areas around the south pole get light all day as the Earth rotates, while those areas at the north pole are in darkness all day. (So I guess Santa Claus will be finishing up his list with the assistance of gas lanterns or a cozy fireplace). The exact timing of the solstice this year is 5:38 pm CST.

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Summer 2010 begins Monday, June 21!

And you're probably thinking: "It's just starting?? What about all this heat we've had the past month??"

Even though temperatures have been above normal for a month straight now, and it's been 94 or higher for eight consecutive days with no end in sight, the summer solstice officially takes place on June 21 at 6:28am CDT. So, while meteorological summer started on June 1 (and it seems more accurate this year given the weather), technically June 21 is the official first day of summer.

The solstice is the point in time when the Earth's axis is most inclined toward the sun, yielding the longest day of the year for the Northern Hemisphere, thus the beginning of our summer. It is also the day when the apparent position of the sun is the highest in the sky for those in the Northern Hemisphere. The graphic above shows the illumination of the Earth at the summer solstice. Notice that the areas around the Arctic circle get light all day as the Earth rotates, while those areas near the south pole are in darkness all day. So, even though we've already sweated through the month of June, welcome to summer!

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