Category Archives: Will’s World Wide Weather

Tornadoes in Pennsylvania

Though many feel that the possibility of a tornado to occur in Pennsylvania is almost nonexistent, nothing could be further from the truth.  Depending on where you are in the State of PA you could be in the tornado alley of Pennsylvania.  The primary locations in which tornadoes occur tend to be in North Western, South Western, and South Eastern regions of our state.  Counties such as Crawford, Westmoreland, and Lancaster have all experienced in excess of thirty tornadoes since 1881.

2010Tornadoes

Back on May 31st 1985, the state of Pennsylvania was the epicenter of a severe tornado outbreak, the deadliest in our state’s history.  In total, 43 tornadoes touched down including eight F4 tornadoes, one of which went through the state forest to our north, and a F5 tornado in the Sharon PA area, that decimated the town of Wheatland PA.

VIS_SAT_1985_MAY_31_smvisible satellite imagery from NOAA

As you can see from the satellite loop, the storms really develop towards the end of the loop, which was the late afternoon on May 31st.  The timing was one of the key factors in the number of people killed, because the morning was beautiful so many people went outside to enjoy the day, with tornadoes being the last thing on their mind.  In the end 88 people lost there lives.

Of the 41 tornadoes that occurred on that day, two were very powerful long tract tornadoes that ripped across Mercer and Venango counties.  The first was and F4 tornado that devastated Atlantic PA

AtlanticTornado1Atlantic PA tornado NOAA

Worst of them all occurred in Mercer county and destroyed the town of Wheatland PA.  At approximately 6:30pm the F5 tornado touched down outside of Niles OH, and continued across the PA/OH border in to the Sharon area.  Leaving 18 people dead and over 300 injured.

107_Village_PlazaF5 in Niles OH

In the end, May 31st 1985 will always stand out, as one of the deadliest days in weather history for the State of Pennsylvania, and even though I enjoy this kind of weather, we will most likely never see such a day again, on this day everything was perfect for the development of this outbreak, and it would be rare to see this happen again.

641px-May31CLEtracksTornado paths during the Outbreak.

Have a great summer and always be aware of your surroundings, and stay one step a head of what ever weather you might experience.

 

 

 

 

MicroBursts

So this week I will be beginning multipart seris on severe weather.  It wont be about the usual, lightning and so on, however more uncommonly seen severe weather such as this weeks topic of a Micro Burst.

Of all the forms of severe weather, such as tornadoes, lightning, and hail, it might be hard to believe, but wind is the most deadly of all of these forces.  More people are killed by wind than tornadoes every year. Whether it is straight line wind from a thunderstorm or a microburst, wind is the real killer.  Of all wind related events, none is more sever than that of a microburst.

A Microburst is essentially a rapidly descending column of air, also known as a downdraft, the forms at the base of a thunderstorm super cell.

micro

These straight line wind make determining whether or not the event was a tornado or mircoburst fairly easy, because all the damage is blown out from a single location.

damage

Though it is still debatable whether it was a tornado or a micro burst,  a micro burst was possibly responsible for taking down one of Northwest Pennsylvania’s most historical sites.  The Kinzua bridge, once the tallest railroad bridge in the US and at one time the world.

732PaKinzuaBridgeSKYWALK_Aerial_IMG_1922

 

Fire Weather

erh

In the map above, you can clearly see the currently the state of Pennsylvania is standing out like a sore thumb. Why is that? Its because currently as you read this the state of Pa is under what is know as a red flag warning, which means there is an extreme risk of rapidly spreading wildfires.  So if this is about just the possibility of forest fires, why is the Nation Weather Service in charge of issuing these Red Flag Warnings?

Actually the Nation Weather service has a lot of say when red flag warnings are issues, because they are truly a fire weather warning.  Fire weather is a combination of many factors the increase the potential for wild fire growth.  Typical it consists of a low relative humidity “The amount of moisture in the are” and also the speed of the wind for that day.  When there is a low relative humidity, more of the moisture contain within the fuel for a wild fire evaporates causing it to be more combustable.  The higher the wind speeds, the quicker the wild fire can spread.  So with dry fuel and high wind, the potential exists for a large forest fire.  This is one side of meteorology Im very interested in and would like to pursue.

fm_10_f

This map show the current percentage of moisture in the fuel for a fire,  as you can see the State College area is between 5-8% so the fuels are extremely dry.

All images from National Weather Service State College

 

 

¿Dónde está primavera?

The question that has many wondering, Where is Spring?  Unfortunately it is truly no where to be found, since this weekend and next week we will most likely staying in the mid forties to lower fifths.  Though its not the sixty or seventy degrees that we all wish would occur, we will have to live.    There will be a slight trough of lower pressure that will bring warmer temperature a head of some rain on Sunday Night.

warm

 

Unfortunately it’s not to last however, Sunday night we might see the return of precipitation, in the form of rain both Sunday night and through the beginning of the week, at least it should mainly be rain.  But as we all know, here in State College, you never know what might happen.36426099

Controlling the Weather

This week in weather history, marks the one of the first scientific attempts, to control the weather.  During this week in the 1950’s, New York City was continuing to suffer from a severe drought.  Most of the cities water reservoirs had begun to dry up and the use of water was being strictly reserved.  Thats when New York City hired meteorologist Wallace E Howell, who had developed a process of making artificial snow, to come to New York City and make it rain (Fountain).  Wallace used a process that involved using dry ice and iodine, to create nuclei for water droplets to form, he called this process, cloud seeding(Fountain).

According to many, they felt that the process was working, multiple newspapers reported storm clouds, rain, and even a snowstorm in April (Fountain).  At the end of his contract the reservoirs for NYC were back to normal levels.  There is still great doubt, and lack of scientific evidence, wether or not the rain was truly caused by Wallace.  The idea of weather modification still exist today, but with the purpose of trying to stop severe weather, such as dumping liquid nitrogen in the ocean to starve a hurricane of warm water.  I personally feel that we should just let nature run its course.

In Other News

Punxsutawney Phil has been indicted by the county of Butler Ohio on the charge of misleading the nation into believing the spring was coming early.

 

Fountain, Henry. “Wallace E. Howell, 84, Dies; Famed Rainmaker in Drought.” The New York    Times. The New York Times, 06 July 1999. Web. 22 Mar. 2013. <http://www.nytimes.com/1999/07/06/nyregion/wallace-e-howell-84-dies-famed-rainmaker-in-drought.html>.

Weather Models

Weather models have been in the news recently, and the US weather model has been under fire for the reasons that it seems as though the European Weather Model is out doing the US model and is predicting the weather more accurately.  There are many reasons behind this, but first  lets cover all of the different models used by meteorologists, since there are so many to choose from.

Many different countries put out dedicated weather models.  The US has then North American Model abbreviated, “NAM”and the Global Forecast System “GFS”.  Canada produces the Canadian Model “CMC”, a Europe as a whole uses the European Model, “Euro”. Finally there are the independent models such as Accuweather’s Galileo.  All very different models that try to convey what their data is saying the weather will be.

So what makes for a good weather model?  In the realm of weather models, it’s all about resolution.  The more location data points the models uses the better the resolution and the clarity of what the model is predicting.  The internal computer system that runs the model is also a large factor.  This is where the US model fails.  For many years the US weather models were left unchanged, while the European Model continued to advance with technology.  This is why the Euro  out performs the NAM.  However the National Weather Service is addressing these issues, and plans on updating the US models in the near future.  So some day the United State might once again be on the top for weather forecasting.

Spring Break

This spring break is going to be really neat spring break depending on where you decide to give if you are traveling to a typically spring break vacation locations like the Outer Banks in North Carolina. The Outer Banks next week actually has the potential to see some snow.  Which I find really ironic because many people tend to travel there to get away from the weather around here.  A prime example of this is the fact that my special living option, The Earth and Mineral Science House, will be traveling to the Outer Banks as a house trip.  I on the other hand will not be attending.  So I wish everyone safe travels to where every you many  be going.

In other news. You may or may not have heard, that today is officially the first day of meteorological spring.  So what is the main difference between spring and meteorological spring you may ask? Well as you may know spring is caused by our location in relation to the tilt of the Earth’s axis.  In the meteorological world however, it all has to do with temperatures.  Meteorologists break down every season into three month time intervals, and these time intervals are determined by the mean temp for that time.  So for the next three months we should see gradually increasing average temps, in the end leading to meteorological summer.

Update

Many of the weather models we use on a daily basis are starting to indicate some sort of winter storm that will hit the East Coast in the middle of next week.  Here is a possible snow fall accumulation map, from the State College National Weather Service.

419905_507342829316809_1498803681_n

Freezing Rain

Since today we have the possibility of experiencing some freezing rain later this evening and into the overnight hours, I felt that today would be a good day to cover how freezing rain occurs and what conditions are necessary in order to get freezing rain.

In the case of freezing rain, its all about the temperature at ground level and above the ground level.  There must be a specific pattern of temps above ground level in order to get freezing rain. If not, you’ll receive just snow or just rain.  The diagram below shows the temperature in relation to the height above the ground. Temperature is on the x axis, and height on the y axis. skewtkunv.16535image from NOAA

In the above image, it shows the temperatures here in State College this morning.  The black line represents the 0* C line and the red line is the actual temp.  In this case all of the red line is to the left of the 0 C line, so in this case we would get just snow.

skewt.30089image from NOAA

If we look farther to the west however in Dubois PA, we see something different.  If you follow the red line down, just above the ground, it crosses the 0 C line, then back to its left. This means, as a snow flake falls from the upper atmosphere just above the ground it melts, but at the ground surface it freezes again, so hence the term freezing rain.

This Week in Weather History

The week of February 10th through the 15th is a fairly important part of weather history,  during this week back in 1983 there was a major blizzard that hit Washington DC, and south central Pennsylvania. In 2007 there was also a major blizzard that brought more than twenty inches of snow to some areas in New England, but also caused a tornado outbreak in southern United States.

The 1983 storm occurred between the dates of February 10th through the 12th and brought snow fall amounts of nearly three feet in some places to the south of Pennsylvania including Washington DC.  On the night of the 10th of February, there was a strong area of low pressure of the Georgian coast.  As I said in an earlier blog, air around the low circulates counterclockwise, which brought moist air of the cold ground in the DC area which was the primary cause of the snow.

1983_surface_stdimage from NOAA

Back in 2007 however, the blizzard know as the Valentines day blizzard, formed much differently due to the fact that it was a low pressure system that moved in from the western coast.  This in turn caused the snow to be centered around the New England region.  Coming from the west also caused this system to produce tornado storms in the south, due to the cold dry air meeting warm moist air from the Gulf of Mexico.

Feb242007_blizzardimage from NOAA

So from a blizzard in 1983, a blizzard and severe weather in 2007, to the surprise snow storm on  Wednesday, with the best packing snow ever, this week in February in truly unique.

 

 

 

 

Snow

So if you have watch the Weather Channel at all lately, you’ll see the almost 24 hour coverage of what the Weather Channel is calling Winter Storm Nemo.  This storm is of a Noreaster type, which means it is traveling up the Eastern seaboard and heading directly for the New England states.  What, makes this storm different however?

In this case, there was a low pressure system moving across the country from the west which is merging with the Noreaster.  The combination of the two will bring heavy snow fall to places like Boston and New York City. The storm has the possibility of setting some record snowfall in some locations.

snowimage from meteorology department of Penn State

The low to the left is the system that came from the west and the one on the right is the Noreaster.

Three years ago on this same weekend the US was affected by another Noreaster, the North American Blizzard of 2010. The current storm is following the same approximate path as the blizzard in 2010.  The main difference between the two is the fact that the current storm contains the extra low pressure system.

snow 2010image NOAA GOES Satellite

Image of the North American Blizzard of 2010

In weather around the world, on Monday February 4th, an 8.0 earthquake struck off the coast of the Solomon Islands, causing a medium sized tsunami

What a Week

So this week was one of the most unique weeks yet in my time here at Penn State so far.  Starting the week with freezing rain on Monday, followed by a nice sneak peek of spring on Wednesday, and finally lake effect snow with arctic temperatures to close the week.  So here is a description of what caused us to have such a weird weather week.

In figure one you can see there is a center of low pressure in Canada, which is the sole reason behind the weather this week.  As you can see the is a warm front (red line) to our east and a cold front (blue line) to our west.  Being in between both of these caused us to lie in what is known a warm sector, which had temps in the 60’s

warm frontfigure one

A warm sector is caused by the rotation of air around the center of low pressure.  As the air rotates counter clockwise around the low, it draws warm moist air from the Gulf of Mexico which gave us temperature in the upper 50’s.

warm circulfigure two

Just past 9pm on Wednesday, the cold front past through Pennsylvania, and are temperatures began to drop steadily, and they are still dropping. By 8am Thursday  morning we were at 30 degrees.

cold frontfigure three

So what caused the snow on Thursday?  Remember that the air around the centre of low pressure rotates counter clockwise, so after the low moved to our east, this brought cold air from the north.  This cold air moved across the warmer moist air above the great lakes, which caused us to get the lake effect snow we saw on Thursday.

jet streamfigure four

In the map image above, you can see that the jet stream curves down from the north and travels through our area.  This is going to bring the return of cold temperatures for next week, so bundle up.

Blank US map by Northern Arizona University, Department of Geography.