Archive for September, 2011

Weather Blog: Summer Numbers & Up & Down Labor Day Weekend
September 1, 2011

Thanks for stopping by the WeatherWatch 12 Blog!!

Luke Sampe  here and we are going to talk about Summer 2011, and look at the hot and muggy start to September and the Labor Day Weekend rollercoaster!

This week is flying by and we are almost to the holiday weekend!

Labor Day Weekend often times marks the unofficial end to summer…I know it’s a bummer for some, but the end of one season and the changing to another is what makes living in Wisconsin so “interesting”…right???!!!

In fact, from a records standpoint, Summer 2011 is OVER!

You see, there are several ways to gauge a season, and for measurements and records, “Meteorological Summer” starts June 1 and last through August 31. Why the difference you may ask….well consistency really.

Having everyone calculate averages to even points on the calendar allows for easier comparison. Don’t worry for you summer lovers, Astronomical Summer still lingers on for another 3 weeks or so.

So now that Summer 2011 is in the books, lets talk some stats…

It turns out Summer 2011 racked up 13 days in the 90s, that over doubled the 6.4 days we average!

Milwaukee’s hottest temperature happened on July 20th when the mercury soared to 98 degrees at Mitchell Field! We did not hit 100 degrees however this summer.

We averaged a high temp of 80 degrees and a low temp of 63 degrees which puts us about 2 degrees above normal in the temperature department for Summer 2011.

As for precip, well it was a dry season. We only logged 7.63″ of rainfall through the coarse of the entire 3 month season! That’s a daily average of just 0.08″ of rain! We ended up about 4″ below our normal seasonal summer totals.

We certainly need the rain and as we head into fall and winter, typically moisture availability decreases as temperatures cool down. For the year we are running abouth 0.90″ down from normal in the precipitation tally….so 2011 could end up a dry year.

Now onward and upward…

Today marks the start of a new month and we aleady are feeling the looming rendezvous of heat that will kick off the Labor day weekend. Get ready for a rollercoaster in terms of temps, humidity and even a few storm chances.

First off, lets starts with Friday, many of you may have travel plans, let’s hope your A/C is working well. Highs will easily jump into the upper 80s to low 90s across much of our area. Here’s a look at the high resolution in house model known as the RPM model. We use this model for guidance in many areas of the forecast and I think you can see what we mean!

You can easily see the difference in airmass from SE WI, to NW WI. Anytime you see a stark contrast like this (80s/90s to low 70s, there has to be a front moving through, and that is exactly what is going to happen. The first of a series of cold fronts will arrive Friday afternoon. With all the heat and humidity around, there will be plenty of fuel for t-storms. The cold front approaching will act like a source of lift and help to hoist up the high energy, moisture filled air Friday afternoon to Friday night prompting a threat of some storms to fire.

Here’s the National Weather Services’s Outlook for severe weather Friday evening and night.

It does look like the greatest chance of storms and rain would be Friday evening and lasting into Saturday off and on. Especially the first half of Saturday. Here is a few images taken from our RPM model depicting clouds and precipitation into early Sunday.

Notice the broken line of t-storms in southern WI Friday late afternoon.

 Again, a few scattered showers and storms are possible into Friday night. So grab the umbrella just in case you might catch one heading out to Friday night football!

 Here’s midday Saturday, and it looks like the greatest threat for rain would be in our southern counties (south of I94 on Saturday).

It does look like by Sunday, the first of two cold fronts will be far enough away that mostly sunny skies should prevail, but we will notice temps will be back down in th 70s with much drier air filtering in. And come early Labor Day Monday, another reinforcing shot of cool Canadian air will arrive, putting highs in the 60s by Labor Day itself!!

Here’s a look at the setup Sunday and Monday…

I hope you have a great holiday weekend. Of course tune into 12 News tonight and Friday for the very latest on the weekend forecast details.

Meteorologist Luke Sampe