What are the sources for WeatherOnline forecasts?


The WeatherOnline forecasts are created by using a MOS system developed in-house with the most current US weather services model data (GFS). The statistical methods of the Model-Output-Statistic (MOS)-System were developed in cooperation with the Meteorological Department of the University of Bonn.

What is a MOS-System?


A Model-Output-Statistic (MOS)-System combines the data of the weather forecast model and the locally recorded data for any given point by transforming the model data from a coarse grid to detailed small scale areas.
In order to do so, one needs a large volume of past model forecast data as well as the corresponding recorded data for any given location. The MOS-System relates these two sets of data in an optimized fashion allowing development of the local weather forecast by using the most current model forecast.

What are the time intervals used in the temperature and icons of the local forecasts?


The forecasted maximum temperature always refers to a 12hour window from 6am to 6om local time.
The forecasted minimum temperature always refers to the 12hour window from 6pm of the day before the forecast day to 6 am of the forecast day.
The weather icon for the morning refers to the time between 6am and 12pm local time, the icon for the afternoon is valid from 12am to 6pm local time and the evening icon refers to the time from 6pm to 12am local time.

How often are the current weather conditions and forecasts updated?


The current weather information as well as the satellite images are updated every 30 minutes whereas the radar images are being updated every 15 minutes.
The local weather forecasts as well as the weather charts are updated 8 times a day. The updates start at 2 am CEST or 3 am CEST depending on daylight saving time and continue on a three hourly bases.


Nearby Weather Stations - Portsmout Distance
Skyhaven Airport 13.0 km
Sanford Seacoast Regional Airport 16.1 km
Beverly Regional Airport 21.4 km
Logan Intl. Airport 35.5 km
Lawrence Airport 36.0 km
Eastern Slopes Regional Airport 38.2 km
Plymouth Airport 43.8 km
Milton 45.0 km
Taunton Airport 49.6 km
Norwood Memorial Airport 52.3 km
New Bedford Regional Airport 53.2 km
Hanscom Field 56.5 km
Portland 59.5 km
Otis Air National Guard Base 62.5 km
Martha's Vineyard Airport 65.8 km
Berlin Regional Airport 68.0 km
Mount Washington Airport 68.7 km
Manchester 68.9 km
Laconia Airport 69.0 km
Auburn/Lewiston Airport 69.3 km
Concord Airport 76.2 km
Newport State Airport 76.4 km
Provincetown Airport 76.7 km
Nashua Airport 78.7 km
Cape Cod Gateway Airport 79.3 km
Rhode 84.1 km
Quonset State Airport 85.5 km
North Central State Airport 86.0 km
Mount Washington Regional Airport 93.2 km
Chatham Airport 104.9 km
Fitchburg Airport 105.6 km
Plymouth Airport 107.5 km
Nantucket Memorial Airport 107.9 km
Block 109.6 km
Beauceville 114.1 km
Thetford Mines Rcs 118.3 km
Worcester Airport 122.2 km
Augusta State Airport 122.3 km
Westerly State Airport 126.2 km
Wiscasset Airport 127.4 km
Sherbrooke Airport 128.7 km
Jaffrey Airport 132.1 km
Lenoxville 137.9 km
Waterville Robert LaFleur Airport 138.2 km
St. Johnsbury 141.7 km
Beauport 141.9 km
Montauk Airport 141.9 km
Ile d`Orleans 143.2 km
Ste Foy (U. Laval) 143.5 km
Caledonia County Airport 143.7 km
Cap Tourmente National Wildlife Area 146.0 km
Québec 148.1 km
Groton 150.6 km
Charlevoix (Mrc) 155.6 km
CFB Valcartier Airport 156.9 km
Fort Montmorency Rc RCS 158.1 km
Windham Airport 159.4 km
Dillant 161.5 km
Orange Airport 162.4 km
Greenville (Amos) 164.1 km
Lebanon Airport 166.3 km
Parc Des Laurentid 168.5 km
Magog 169.3 km
Northeast Kingdom Intl. Airport 169.6 km
East Hampton Airport 176.4 km
Lemieux 178.4 km
Deschambault CS 180.9 km
La Pocatière 182.4 km
Hartness State Airport 189.5 km
Westover Metropolitan Airport 193.6 km
Knox County Regional Airport 194.7 km
Chester Airport 197.2 km
Edward F. Knapp State Airport 198.7 km
Morrisville- Stowe State Airport 206.7 km
Hartford Airport 209.4 km
Bradley Intl. Airport 211.6 km
Westfield-Barnes Regional Airport 214.0 km
Francis S. Gabreski Airport 215.2 km
Trois-Rivières 219.5 km
Rivière-du-Loup 227.0 km
Meriden Markham Airport 229.3 km
Nicolet 231.5 km
Bangor Intl. Airport 232.2 km
Frelighsburg 236.4 km
Rutland- Southern Vermont Regional Airport 238.0 km
Tweed New Haven Airport 238.9 km
Brookhaven Airport 241.3 km
Shawinigan 245.0 km
Middlebury State AP 255.6 km
Lake Saint Pierre 257.2 km
Millinocket Airport 257.2 km
Harriman-and-West Airport 261.9 km
Franklin County State Airport 262.1 km
Waterbury 264.0 km
Burlington Intl. Airport 264.1 km
La Tuque 265.3 km
Long 266.0 km
Sikorsky Memorial Airport 266.2 km
William H. Morse State Airport 269.1 km