Fall is showing more and more of its presence across the Twin Tiers. More trees are starting to show their colors and the nights have become a bit chilly.

A Canadian high will build in over the weekend, bringing very dry air and very chilly conditions at night. It appears we have all the ingredients for very good radiational cooling Saturday night. This will be the coldest night of the next 5 days, and the coldest since June 1st, when we hit 37 degrees at the airport. We are now watching for the possibility for frost Sunday morning. At this juncture it appears that the sheltered/rural valley locations have the best chance for frost, while the urban areas should remain frost free. The normally cold spots could see temperatures drop into the 34-37 degree range. Brrrr!

How normal is frost in September? Well the average first frost occurs between September 30th - October 10th for most areas along and west of I-81. East of I-81 the average first frost occurs between September 20th - September 30th. Only the highest elevations of Delaware County see it earlier than the 20th. At this time of year it is difficult to get freezing temperatures. However, temperatures below freezing have occurred as early as September 20th, 1993 at the Binghamton Regional Airport when the temperature dropped to 29 degrees.
 

Super high-resolution spy satellites have been imaging sea ice at the poles for the last decade on behalf of earth scientists. Believe it or not, the images have been kept secret from the public and nearly all scientists. Over the last 10 years, a tiny group of scientists with security clearance was able to see some of the images, but couldn’t use them publicly.

Now, the United States Geological Service has published a set of high resolution images. The images have been released after the National Academy of Sciences or NAS recommended that the arctic images be made public to help scientists examine climate change and the impacts of diminishing sea ice.

The committee emphasized that these Arctic images show detailed melting and freezing processes and also provide information at scales, locations, and time periods that are important for studying effects of climate change on sea ice and habitat -- data that are not available elsewhere.

With the new info in hand, scientists should be able to build better models of smaller sea-ice features like melt ponds and ridges. Both are believed to have important roles in sea ice dynamics, but how important they are remains unclear.

The information released could be part of a larger trend in which the scientific and intelligence communities realize that they share a concern for environmental problems. The sea ice images can be found at the following website: http://gfl.usgs.gov/ArcticSeaIce.shtml

There has been a lot of talk about the lack of sunspots. We just recently had a stretch of 51 days without any sunspots. This is just shy of the 52 day record (set last summer) of this sunspot cycle. It is becoming increasingly likely that the number of spotless days will be the longest in about 100 years. There is no sign that sunspots will increase so far.

Recently I came across an article from NASA on the disappearance of sunspots. Click here for a link to that article. You’ll find it an interesting read. 

The moon is full and bright. It’s September, so it must be the harvest moon. Right? Not so fast!

The harvest moon is called that, because back in the days when there were no light bulbs farmers harvested their crops late into the night. It is also the full moon nearest to the autumnal equinox. Tonight’s full moon is not the harvest moon because it occurs too many days before the autumnal equinox. Instead, the harvest moon will occur October 4th.
 

An updated August Atlantic hurricane season outlook calls for a below normal Atlantic Hurricane season. This is due to the calming effects of El Nino. As El Nino continues to develop, it is likely that the hurricane season will end on a quiet note. However, despite the quiet start it is still possible for strong hurricane to develop so it is important for people to still be prepared.

NOAA’s Climate Prediction Center now predicts a 50% probability of a near normal season, a 40% probability of a below-normal season, and a 10% probability of an above normal season. Forecasters say there is a 70% chance of seven to 11 named storms, of which three to six could become hurricanes, including one to two major hurricanes.

The main change from the May outlook is an increased probability of a below-normal season. The May outlook called for nine to 14 named storms, of which four to seven could become hurricanes, including one to three major hurricanes.

In recent weeks it has become apparent that El Nino will strengthen. During an El Nino, there is more wind shear in the Caribbean and fewer hurricanes. The stronger upper level westerly winds help reduce hurricane activity by blowing off the tops of growing thunderstorm clouds that would normally lead to tropical storms. La Nina conditions are favorable for hurricanes because they lead to less wind shear in the tropical Atlantic.

Even though El Nino tends to decrease the number of storms, other climate factors could help to create storms, so we’re not out of the clear just yet. The outlook provides a general guide to the expected overall strength of the upcoming hurricane season. According to NOAA, the outlook is not a seasonal hurricane landfall forecast, and does not imply levels of activity for any particular region. So it is always important to be prepared as hurricane disasters can occur whether the season is active or relatively quiet.