Frequently Asked Questions

1. How can I reach the National Weather Service?

Snail Mail:

National Weather Service Forecast Office
Center for Environmental Sciences and Technology Management
251 Fuller Road Suite B300
Albany, NY 12203-3640

E-mail the Web Team

2. Why have we gone to a new WEB Page?

The National Weather Service has decided that by February, 2002, all National Weather Weather Service Office (there are over 100) will have similarly formatted WEB pages. While this initially may cause some adjustments, it allows to offer more weather information faster.

3. Where can I find a glossary of weather terms?

4. For what period of record do normal temperature and precipitation data come from?

Normal temperature and precipitation data are based on average values during the 30 year period 1971 to 2000. The values are based on a 30 years of data and are recomputed every 30 years. In the year 2010 they will again be recalculated based on the period 1981-2010. Due to the recent warm weather normal temperatures are slightly higher than those computed for the period 1961 to 1990.

5. What is the criteria used to determine if a severe thunderstorm warning is issued ?

Winds in excess of 50 knots (58 mph)
3/4" or larger hail
If a tornado touches down

6. What are blizzard conditions ?

A blizzard means the following conditions prevail for a period of 3 hours or longer:

Sustained wind or frequent gusts to 35 mph or greater
Considerable falling and/or blowing snow

For example, the snow frequently reduces visibility to less than 1/4 mile. There is no set temperature requirement for blizzard conditions. However, the life-threatening nature of low air temperatures combined with the other perilous weather conditions of wind, snow and poor visibility increases immensely, when the air temperature falls below 20 degrees Fahrenheit.

7. What is the difference between blowing and drifting snow?

Blowing snow is wind-driven snow that reduces surface visibility. Blowing snow can be snow falling or snow that has reached the ground, but is picked up and blown by strong winds. Blowing snow is usually accompanied by drifting snow. Drifting snow is an uneven distribution of snowfall/snow depth caused by strong surface winds. Drifting snow may occur during or after snowfall.

8. What snowfall accumulations or durations are associated with heavy snow ?

Heavy snow can be:

Snowfall accumulating to 7 inches or more in depth in 12 hours or less
Snowfall accumulating to 9 inches or more in depth in 24 hours or less

9. What are wind chills ?

Wind chills are produced by a combination of wind speeds coupled with the current outdoor air temperature. This resultant temperature produced would be what the temperature would feel like on bare skin. Basically, increased wind speeds increase rapidly heat loss from exposed skin. The National Weather Service uses -25 degrees Fahrenheit as a general rule for a threshold for potentially dangerous wind chill conditions.

10. What are Chinook winds and where do they occur ?

Chinook winds are warm, dry winds that occur on the lee-side of high mountain ranges. Frequently, they occur along the mountains in the western half of the contiguous United States and in Alaska. These winds can develop in major urban areas and are often very strong. Large amounts of snow can melt from strong Chinook winds.

11. I need climate information. Where can I find data?

Check out our Climate Page.

National Climate Data Center (NCDC)
Federal Building
151 Patton Avenue
Asheville, NC 28801-5001
Contact Information

Northeast Regional Climate Center
1123 Bradfield Hall
Cornell University
Ithaca, NY 14853-1901

12. Where can I get pressure data?

Surface weather observations contain pressure information. Check out our observations page. We broadcast the current pressure on NOAA Weather Radio. The pressure trends ,rising (R) or falling (F), can be found on the State Weather Round-ups.

13. Where can I find information about El Nino?

The Pacific Marine Environmental Laboratory has a dedicated web page.

14. Where can I find information about fire weather?

Visit the NWS National Fire Weather Page maintained by NWS Forecast Office Boise Idaho. Also, the Storm Prediction Center issues fire weather outlooks.

15. Where can I find more information about hurricanes ?

The Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division has a page dedicated to FAQs about hurricanes.

16. What are heating and cooling degree days ?

Heating and cooling degree days used to determine how much power people should be using on the average to cool/heat their homes and businesses. Degree days are calculated by using the average temperature for the day and its difference from the number 65. The number 65 is used as the base number because most buildings and homes would be most comfortable and energy efficient around 65 degrees.

Example:

On a summer day the high was 90 and the low 70 = average 80.
80 (average) - 65 (base) = 15 cooling degree days.
On a winter day the high was 40 and the low was 0 = average 20.
65 (base) - 20 (average) = 45 heating degree days.

17. Where can I find information on global warming ?

Try this NOAA web site as a starting point: FAQs on Global Warming .

18. How does doppler radar work and how do I interpret the images ?

The following NWS web site on Doppler Radar will give you the information you need.

19. Where can I get marine forecasts, observations, safety information, etc. ?

Go to this comprehensive NWS web site: Marine Forecasts