Van_Denton's Blog

This week (specifically, Sept. 10th) marks the peak of Hurricane Season.

The peak is based on activity in the Atlantic basin over the past 100 years. 

Notice that on the 10th, there have been 96 active storms on that date in that time period.  In other words in most years, that has been at least one active Tropical Storm our Hurricane on that date.  Some years there have been more than one.  Just last week, we had 3 active storms at one time.

Also, notice that by the end of the month of September, that number fall to nearly 50, or almost half the activity.  That is good as the season activity drops off rapidly after the peak week.  There is a little spike in mid-October.  Typically, by then, the westerlies take over and protect our area.   However, in 1954, Hurricane Hazel ripped through NC in Mid-October.

The season doesn't officially end until November 30.

Had Fay been over open water for a long time, there is no doubt it would have become a hurricane.  Possibly a major hurricane.  However, its track over Cuba and later Florida prevented that from happening.  Still, the storm has already made the record books.  

More than 2 feet of rain in parts of Florida and 3 Landfalls as of Thursday, August 21.

First landfall was near Key West, Florida then it was Cape Ramano on the SW Coast of the state and finally Daytona Beach.   However, it could make a 4th if it actually makes it back into the Gulf of Mexico and then touches the Florida coast again.

Already, the 3 landfalls ties the record for the most landfalls from a single tropical system in Florida.  

 The others: 

1. 1878  Unnamed storm
2. 1950  Easy
3. 1960  Donna
4. 1994  Gordan
5. 2008  Fay

If it can make it to 4 landfalls, it will stand alone.

It is time.  As of this writing, Friday morning at 2:22 am...there are no Tropical Depressions, Storms or Hurricanes in the Atlantic.  However, from what I can tell, it is about to change.

The system moving near Puerto Rico this morning has me concerned.  It appears to be headed into a favorable environment and could rapidly development late in the weekend and early next week.

Here is a great link for those that like to track the tropical models

http://moe.met.fsu.edu/tcgengifs/

Most everyone has heard about the Dog Days of Summer.  But, do you know where the term came from?

The ancient Romans observed that the brightest star in the constellation Canis Major (the big dog), Sirius, was rising and setting with the sun from near July 3rd through August 11th.  This led them to believe that it added heat and was responsible for this being the hottest part of summer.

 I am looking forward to August 12th when the Dog Days are over.   Bring on autumn.

Over the past weekend, many viewers saw vivid rainbows and some even saw double rainbows.  Many of those pictures have been featured in blogs on this site.

So how do we get a Double Rainbow?

From UCAR.....

"Sometimes we see two rainbows at once, what causes this? We have followed the path of a ray of sunlight as it enters and is reflected inside the raindrop. But not all of the energy of the ray escapes the raindrop after it is reflected once. A part of the ray is reflected again and travels along inside the drop to emerge from the drop. The rainbow we normally see is called the primary rainbow and is produced by one internal reflection; the secondary rainbow arises from two internal reflections and the rays exit the drop at an angle of 50 degrees° rather than the 42°degrees for the red primary bow. Blue light emerges at an even larger angle of 53 degrees°. This effect produces a secondary rainbow that has its colors reversed compared to the primary."

By the way under ideal conditions it is possible to get as many as 4 rainbows, however most people will never observe more than 2 at once.

Summer is here...it arrived at 7:59 pm, Friday night, June 20.

We've already had hot weather this year and we know that we will get more.  Have you ever noticed that even on our hottest days, you can find relief in our mountains?  Do you know why?

Due to physical properties (density of the air and surrounding air being elevated well above the surfaces so less heating from solar radiation), the air cools with height an average of 3.6 degrees F per 1000 feet.

Here in the Piedmont-Triad, our elevation is between 800-1000 feet in most areas.   Boone's elevation is approx. 3500 feet.   This 2500 foot difference is responsible for the 9-10 °F drop that is often observed.  How about Mt. Mitchell (our highest mountain) at 6684 feet.  That is a difference of about 5700 feet or about 20 degrees.

So on our hottest days when the high may reach 95-97, it will be around 75 on top of Mt. Mitchell.

Have you noticed the smoke?   The wildfire in eastern NC, near the outer banks, has brought a smoke haze and smell to the Piedmont-Triad.  The smoke has traveled nearly 200 miles to get here and has been pushed by winds from the east blowing to the west.

You may have also noticed it is worst at night and in the mornings.  That is due to the inversion that sets up at night, which keeps the smoke closer to the surface and more concentrated.   During the afternoon the air mixed due to heating and this mixing helps clear our air.   Still the air quality has not been very good.   Here is a link to the Forsyth County Environmental Affairs office website where they measure our Air Quality.

http://www.co.forsyth.nc.us/envaffairs/dailyforecas
t.aspx

At times the air quality has been in the RED.

Over the coming days our wind direction should change and that will help here.  A west wind could bring smoke to some of our northern beaches.

So far this spring has been pretty comfortable.   As of this writing, we have not reached 90 degrees yet.   But, it won't be long.

The normal summer brings 30 days of 90 degree plus heat.

Do you like it hot or do you prefer cooler weather?

We are now entering into a very active weather pattern. One that is likely to produce some severe weather.

Thursday night we are under the gun with a potential for damaging winds and some hail. A good night to have a weather radio on stand-by. If you don't have a weather radio, they make a great investment and can be found at most electronic stores. Also, they can be purchased online. Just do a Google search NOAA Weather Radios.

There is also a great deal of concern about Mother's Day and the potential for a significant ourbreak of severe weather. I know many of you will be busy with Mother's Day, Graduations, etc. Do keep a close eye on the weather as it could change rapidly.

Here is an excellent link to the severe weather threat that is updated by the Storm Prediction Center every 4 hours. This is the same source that we hear at FOX 8 use for our Storm Outlooks.

Main Page for Storm Prediction Center

Page with severe weather outlooks and details

OK everyone, put your thinking caps on. 

Most years we reach 90° for the first time during the month of May.  Give me your guess of the first date that we will reach 90° and I will mention the person(s) that is(are) closest on the air.   You must have your prediction in by Midnight, Tuesday May, 2008  for it to count and be mentioned.

Before submitting your guess, here is a list of the first date 90° was recorded each year since 2000.

2000   May 13

2001   June 5

2002   May 19

2003   June 26

2004   May 21

2005   June 6

2006   April 15

2007   May 1

2008    ?

My guess.......this year will be a little later than the past few years.   June 10th

Wow!  What a storm some had on Sunday, April 20.  Temperatures were in the mid to upper 60s and then a storm.   First it was rain and then marble sized hail began to fall and kept falling for some.  One of the hardest hit areas was North High Point.

This picture was sent to us by Chuck Potts.  He said he was near the intersection of High Point Road and the 311 Bypass.   By the time the hail stopped falling, the temperature fell to near 40°

The hail was significant due to a cold upper low pressure system tracking over our area.  This lowered freezing levels to below 6000 feet and made hail more likely.

More pictures from our viewers......

The 3 below were sent to us by Darrin Jordan these were from the Willard Dairy and US 68 area.

Thank you to all that sent your pictures in.  Remember to send you weather pictures to photos@wghp.com when you take great weather pictures..

Temperatures are now warming into the 70s and many are thinking about spring and gardens.  Might as well since we are done with the cold right?   Think again, we are not done with the cold and that is perfectly normal.   We expect cold weather again the week of April 14th.   We are 6 days out (writing this on April 9th), but it looks like we could be close to freezing around sunrise on Tuesday morning, April 15.

Records date back to 1928 for the Triad area and after comparing all 80 years we have found that the average last freeze is on April 11th.  The majority of the years fall within 2 weeks of that date.  Some years the last is early and some it is much later.

The latest freeze on record for us was May 8, 1989.   I point this out not to scare anyone away from planting, just to make you aware of what can happen in April and sometimes even early May.

Below is a map with the average latest freeze for the state of North Carolina.

For weeks I have been asked, how can we still be in a drought when our Lakes and Rivers are looking good?

There are several ways that a drought is measured.  Some of these methods no longer have us in a drought.  As a matter of fact the soild moisture is looking really good right now.  The recent rains are going to be excellent for planting and growing crops in the new few months.

The problem is the long-term pattern.  We show the Drought Monitor on television and it doesn't look very good for us.  On Tuesday, I spoke with Jeff Orrock with the National Weather Service in Raleigh and asked him why we are still considered to be in such a drought when everything looks normal.

After speaking with him it is more clear.  For long-term concerns, they look much deeper, literally.  How far does one have to dig to find water.  There are not many places around where readings are kept for groundwater, but one nearby location is in Mocksville.  Typically, this time of year, a digger would have to dig 16 feet to get to the groundwater.  Right now, they must dig 19 feet.  That means at that location, the water level is still 3 feet below normal. 

As it was explained to me, that means that although the lakes look good now, if we have a period of dry weather, the water levels will drop faster than normal due to the dry ground below.  Couple that with the increasing evaporation from warmer temperatures and higher sun angles over the next several months and greatrt water use, there is still a  concern in North Carolina for drought conditions to worsen this summer.

Easter is a holiday that moves on the calendar more than any other.  Some years it is as early as March 22nd and as late as April 25th.  This wide range in possible dates can lead to a wide variety of weather conditions.  Some Easters have been cold and some have been hot.

Last year, the holiday came on April 8th and was quite cold, the morning low was 25°.  As a matter of fact, snow fell just 30 hours earlier on friday night.

But, that was nothing like the Easter of 1915.

On the evening of April 2, 1915 snow began to fall across North Carolina and it fell into the day on April 3rd.   This was one of those Nor’easters that hit the east coast hard and caught many by surprise.   Since the ground was warm, much of the snow melted as it fell or soon after.  However, as you will see below, some of the totals were very impressive in spite of the warm ground.

 Raleigh  14” fell, with a maximum of 10” on the ground at one time

           Some areas near Raleigh were reported to have nearly 2 feet of snowfall

Greensboro 10” of snowfall

Winston-Salem 5” of snowfall

 The snow was heaviest in the eastern parts of the piedmont and along the mid-atlantic coast.

 The very next day, April 4th was Easter Sunday and there was still some snow left early in the morning but it melted away during the day.

This Easter will again be cold and our forecast as of the Monday before Easter is for a COLD Rain.  We will have to keep an eye on this as we have had some interesting weather on Easter in the past.    Below in the comments field, I will keep the forecast updated.

What is the latest snowfall that you remember?

This is about the time of year when many begin to feel it is now too late to get snow.

Here are the facts.

Last year we had our last snow the first weekend of April on the 6th.   Easter weekend was a record cold weekend and we had a dusting of snow on Friday night and Saturday morning before Easter.

The latest snowfall on record in the Piedmont was April 18, 1983.  The Piedmont-Triad Airport recorded only a trace.  However, in parts of the area, some saw a good dusting to an inch.