Cold, Cold, Cold...and did I say cold?

It appears that old man winter has finally gotten a really tight grip on the Mid-Atlantic region, for me that means my first semester studying Meteorology is coming to an end.  I've really picked up a lot of knew knowledge from this class, even if we didn't do the mathematics or science to back it up.  Today is our last class before the final and we are going to try an apply all the things we've learned during the fall and make a forecast.
A forecast is the one tangible thing that people get from a meteorologist, and most people have no idea how much effort forecasters put into their predictions.  Heck, I was one of those people back in September.  Now, I have a very limited knowledge of the art of forecasting, but I have gained a huge amount of respect for the folks that do it.  There are several popular ways to put together a forecast, so I'll share some of the highlights with you.

1. Now-casting. The art of relaying to the people what is happening right now where they are. Twitter is full of now-casts, just look up the Capital Weather Gang, or Accu-Weather, or The Weather Channel. They are constantly posting updates about current weather all across the country.
2. Persistence Forecasting: This is used when the weather pattern is the same, day after day after day.  Use the desert for example.  The forecast of Sunny, and hot is very reliable over a period of days.
3.Climate-Forecasting: This is the art of using the climate data collected for a given area to build a long term forecast.   These forecasts are usually pretty vague but try to give people an idea of what they can expect over a period of weeks or months. 
4.Computer Forecasting: Plugging data from points all over a given area into a computer, and letting the computer model out what it thinks is going to happen. This is how most of our local 72 hour, 5 day and 7 day forecasts are generated.  The computer will run several models with the data that is entered and the forecaster will apply climate data, and current data to try and get as close to the actual events as possible.

So the next logical question is 'What exactly is a good forecast?' The answer that is most popular is "One that is right.", but how do you gauge "right"?  If you got the temperature right, but it was raining and you forecasted sun, were you right?   The matter of being right is difficult to define, so we broke it down into categories that you can score:

1. Did you get the temperature right?  Were you within 3-4 degrees either way?
2. Did you get the conditions right?  You called for rain, did it?
3. Were you able to successfully prepare people for the conditions they will encounter during that day?


So that's the very basics of weather forecasting.  From time to time I'll try to throw a forecast out there, just to see how well I do.  The outlook this week is a simple persistence forecast:  Sunny and COLD for the DC area.  Highs around 35 degrees F all week. You can look at the current U.S. Radar composite and see, there isn't much out there that will impact our region....see for yourself here.  The wind will die down after today though.  So there it is, my 1st official weather forecast, let the criticism begin!

Three Hurricanes at Once!

                              The eye of hurricane Igor 9/13


There are currently three active hurricanes in the Atlantic basin, two of which are major hurricanes.  A major hurricane is defined as a category 3 or higher.  Basically a storm with sustained winds of 115mph or more.  The two major players are Igor and Karl. For the record, none of these storms are a threat to any US coastline. I'll start with Karl.  This storm made landfall in Mexico's Yucatan Peninsula on Wednesday as a strong tropical storm.  It re-emerged over the Bay of Campeche and went crazy, developing into a category 3 monster.  It's now making it's second landfall in Mexico.  The area it's impacting is very rugged with lots of hills and mountains. Wind and rain damage will be extensive as well as a very high mudslide potential.  It's amazing how quickly Karl spun up, the whole thing happening in just a few days.
Igor on the other hand, has been with us for more than a week.  The storm is a classic "Cape Verde" storm for this time of year. He got his act together quickly after emerging from the African coast and intensified to within 1 MPH of being a category 5 storm.  Category 5 storms have sustained winds at or in excess of 155 MPH. Between 1924 and 2007, 32 hurricanes were recorded at Category 5 strength, so they are fairly rare.   Igor has weakened to a category 3 storm with winds of 115 mph and looks to make a direct hit on the island of Bermuda over the weekend.  Most of the buildings on the island adhere to their strict building code so hopefully structural damage will be minimal.
Lastly we have hurricane Julia.  Julia formed up in Igor's wake and hasn't had a very favorable environment to work with.  She also got turned north very quickly after forming.  She's a minimal hurricane with winds at 85 MPH and is no threat to any land mass at all.   According to the article I read on StormCarib.com the have only been eight times since 1850's that there have been three active hurricanes in the Atlantic, so this is certainly a rare occasion. The last time was in 1998 when there were four hurricanes in the Atlantic. 
The weather in the area for the weekend looks awesome.  I would expect the Capital Weather Gang to rate them 9 out of 10's.   Sunny and 80 both Saturday and Sunday, lows in the mid 50's.  Get out and enjoy!  Talk to you next week.

s

Big Storms Last Sunday

 **EDIT:  Here is a link to a great article from the Capital Weather Gang that touches on why the storms we had on Sunday were so strong.**

Power in a large part of Montgomery County is still out today(Tuesday) after a line of really strong thunderstorms ambushed the entire DC/Baltimore region on Sunday.  Montgomery County took the worst hit of the area. The storms that roared through Rockville, Bethesda, and Gaithersburg were tornado warned when they came through the area. It was the second tornado warning for the region in a week!  These were the worst storms to hit the area in several years.  Carey and I were putting up molding at home on Sunday afternoon and we could hear the "alert beep" from the Weather Channel going off endlessly as warning after warning for severe thunderstorms, tornadoes, and flash flooding were issued.  The thunder and lightning were almost constant at our house, it was quite the spectacle.  Luckily we never lost power.  The National Weather Service is investigating the Rockville/Gaithersburg area to see if a tornado actually did touch down.  The weather made for quite an afternoon on Sunday and has successfully made my commute even worse, as some major intersections in Rockville are still dark.  PEPCO announced that some folks wont have power back until Friday.   Storms like this do a lot to help me remember how small I am on the global scale.  Hopefully the rest of the summer is a little less eventful.