Weather Blog

Our low of 80 degrees Friday morning (5-23-08) set a record.

Not only was it the warmest low temperature ever for May 23rd, but it was the earliest in the year we’ve had a low of 80 or above, AND the warmest May low ever.

The previous warmest May lows were 78 degrees, back in 1927, 1995 and 2003

A warm front moving north through the metroplex today will bring higher humidity/higher dew point air back to North Texas.

We’ll notice the big difference in the morning.  The lows in the 60s will climb to lows in the 70s and our a/c will start to have to work 24 hours a day.

Heat Index numbers will climb as well, up toward the mid/upper 90s.

We’ll also see some of those June-like pop-up heat and humidity t-storms.

According to the record books, today’s normal high is 84, and the record, set in 2006 is 98.

Today we’re heading toward record territory, in fact, it looks like the DFW temperature will hit 98.  Parts of North Texas will see 100 for the first time this year, especially NW and W of Fort Worth.

Tomorrow may be just a little cooler, but that should be enough to keep the high in the mid 90s.

By the way, today’s useless fact:  The record high at DFW is cooler than New York City’s record high of 99.

We’re still officially more than a month away from the start of summer, but you’d never know it when you step outside.

This is the first time this year that the Five day forecast has highs of at least 90 degrees all week long!

It will take a few days to cause humidity levels to climb to Heat Index levels, but it will be noticably more humid by week’s end.

About eight months ago, NASA launched a new spacecraft named Phoenix. Since then, it has been cruising toward a rendezvous with Mars, and it’s now just a week away from landing. On Sunday, May 25th it is set to land, but this one will be different. Unlike the Mars Rovers which landed near the equator in 2003, the Phoenix spacecraft will explore the Martian arctic.

Another difference - The twin rovers have each covered more than 5 miles in their historic trek, which against all odds, still contines 5 years later. But the Phoenix lander will be stationary. And because of its landing place in the polar regions, it is only expected to survive for 3 to 5 months. But it will be historic in its own way. Phoenix has an extendable arm, with a trenching tool on the end. It will dig into the Martian permafrost, and then examine the soil and ices under a microscope.

Here’s a link with more information on the mission:

http://www.planetary.org/news/2008/0513_Phoenix_Prepares_to_Land_on_Mars.html

And here is a photo of an artist’s impression of what Phoenix will look like as it nears touchdown:

Ken Kalthoff did a story this afternoon on a Dallas link to the Martian spacecraft. A local professor built a spectroscope that will be used to analyze the spectrums, and determine the mineral content of the soils and ices that the trencher digs up.   Here’s a link to Ken’s blog:

http://kalthoffonthefence.wordpress.com/2008/05/16/utd-to-planet-mars/

Mia the Golden Retriever loves to go places, either on foot, in the car or in the plane!  She even has her own doggie headset!!!

She’s enjoyed the ride to Missouri, to Oklahoma and around Texas.

Just like a kid though, she has her limits, a long time in the plane, or turbulence makes her long for the ground!

By Steve MacLaughlin

I have this love affair with the dew point. I’ve written about it before. I tell my friends about it. I talk about it during my newscasts quite frequently. The fact is, it is the most important number in all of weather, even though most people don’t quite know what it means. But it is everything, and today is a great day to talk about part of its grasp on our lives.

I won’t get into all the science of dew point; it is complicated. The basic definition is the temperature at which condensation occurs. In other words, the temperature to which the air temperature has to fall for all of that moisture floating around in the air that you can feel but can’t see (gas) to turn into moisture we can see (liquid) as clouds or fog or dew or rain or even solid snow or ice. When the air temperature drops to the dew point, the relative humidity is one hundred percent, the air is saturated and condensation and usually precipitation occurs.

The much easier principle to understand needs very few words. If you were outside on Saturday and outside again on Sunday, then you know what the dew point is.

On Saturday, the dew point was 73 degrees before the storms rolled thru. That is incredibly humid. About as bad as it gets around here. If you were outside, you got hit with what felt like a wall of water and the heat index soared to the triple digits with all the humidity.

On Sunday, behind a cold front, northwesterly winds not only cooled us off, but dropped the dew point to 33 degrees. That is incredibly dry. As dry as some winter days. If you stepped outside it felt like a different part of the country. It simply felt wonderful. That is the low dew point and the very dry air.

If you work outside or like me, run outside, you look for low dew points because when it’s drier, it not only feels better, but our bodies are more efficient at keeping cool. Today’s level of moisture is a gift; a rare commodity as we enter the late spring and summer.  Most summer days feel more like Saturday than Sunday.  With high dewpoints in the 60s and 70s, the air temperature feels even hotter. That is the heat index; the temperature our bodies think it is because humidity (high dew points) makes it harder to stay cool.

Enjoy, Happy Mothers Day and have a great week,

Steve Mac