It's 12:10 p.m. Wednesday and if you look at your phone, you'll see that it says we're sunny, or "fair" in southeastern New Jersey.
This is, obviously, wrong and is one of the many reasons why a live, in-person Meteorologist will always been needed to explain and forecast the weather.
Your weather app or website (which we hope is ours even though it, too, is saying it is sunny) is correct, but not truthful. To show you the light (or, dimness), we need to do a little digging into the way observations are coded. That means, a dive into The Federal Meteorological Handbook No. 1.
Most airports around the country have a weather station. These weather stations report on a variety of factors like temperatures, winds, dew point, rainfall and sky cover. These are then put into a code, called METAR, short for Meteorological Terminal Aviation Routine Weather Report. The code is used to help shorten what would otherwise be large amounts of information.
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However, weather stations come in all shapes and sizes. Most stations are automated with larger airports having their own weather observer on site. For the most part, you will not notice the difference. All report temperatures, dew points, winds and rainfall the same. There are two main exceptions, though.
Snowfall, and sky cover.
Automated stations do not measure the snow that is falling (that is topic for another story), places with weather observers do. When it comes to sky cover, both automated and staffed stations report it. Many times, it is with something called a celiometer, which uses a laser to help measure height. However, they do so differently.
Let us go back to The Federal Meteorological Handbook No. 1. The book has the answer. To quote,
"Automated stations shall have the capability to evaluate sky condition from the surface to at least 12,000 feet. Observers at manual stations shall evaluate all clouds visible; the 12,000 foot restriction shall not apply."
Put another way, manual stations must record all layers that are present, up to where it becomes overcast. Automatic stations only need to go up to 12,000 feet.
Philadelphia International Airport has a staffed weather observer there nearly 24/7. Atlantic City International Airport does not have one, though air traffic control can alter the observations in extreme events. This morning is one of those times. Therefore, the automatic entries are used.
So, if you went on say, the National Weather Service website, where your app or website receives the data from and typed in Philadelphia, you would see this.
On the other hand if you went to A.C. Airport, or anywhere near the airport, you would see this.
As we know, though, the region has had sun shielded by clouds. Clouds were 28,000 feet high at the 11:54 a.m. observation. However, this is dropping, so expect your computer or phone to say cloudy later in the day.
So, because there is no weather observer at A.C. Airport Wednesday, tens of thousands of people scratch their heads wondering why the current conditions are wrong. It is not the National Weather Service's fault.
Turns out, you just need to ask a Meteorologist to find out the truth.
