| Interactive Weather Map |
The weather map is centered on your selected location and graphically displays
AIRMETs and SIGMETs. AIRMET and/or SIGMET text appears below the map if your
selected location is within an AIRMET and/or SIGMET area.
Zooming in increases details on the map, eventually displaying current conditions
at area reporting stations. See the Symbols and Legend information to interpret
the station graphic.
|
| Using the Map |
The map has borders with the directions N, S, E, and W. Clicking a border pans
the map one full width in that direction. Clicking inside the map centers the map
at that location and updates the area forecasts, AIRMETs, SIGMETs, winds aloft, and
TAFs.
Clicking the Show Precipitation Radar button above the top borders places radar
precipitation images on the map.
|
| Area Forecasts |
|
Any area forecast affecting your selected location is displayed. An area forecast predicts
Visual Flight Rules (VFR) clouds and weather conditions over an area as large as the size of
several states. It must be used in conjunction with the AIRMET Sierra (IFR) bulletin for
the same area in order to get a complete weather picture.
|
| AIRMETs and SIGMETs |
AIRMETs contain details of potentially hazardous weather conditions including
IFR conditions, icing, and turbulence affecting or forecast to affect an area of
at least 3000 square miles at any one time.
AIRMETs are routinely issued for 6 hour periods beginning at 0145 UTC during
Central Daylight Time and at 0245 UTC during Central Standard Time. AIRMETs are
also amended as necessary due to changing weather conditions or issuance/cancellation
of a SIGMET.
SIGMETs contain details of weather conditions that are considered significant to all aircraft
categories. There are two types of SIGMETs, non-convective and convective. Non-convective SIGMETS
provide information on turbulence, icing, and reduced visibilities while convective SIGMETS provide
information on thunderstorms and tornadoes. A convective SIGMET implies severe or greater turbulence,
sever icing, and low level wind sheer.
Convective SIGMET bulletins are issued for the Eastern (E), Central (C), and Western
(W) United States. The areas separate at 87 and 107 degrees west longitude with
sufficient overlap to cover most cases when the phenomenon crosses the boundaries. Bulletins are
issued hourly at Hour+55, while special bulletins are issued at any time and updated at Hour+55.
The text of the bulletin consists of either an observation and a
forecast or just a forecast. The forecast is valid for up to 2 hours.
|
|
|
| Winds Aloft |
|
Winds aloft forecasts are displayed for your selected location or the nearest reporting station. The
forecasts contain wind direction, speed, and temperature. All altitudes through 12,000 ft are true
altitude, while altitudes from 18,000 ft and above are pressure altitudes. Wind direction is measured
in °T and no winds are forecast within 1,500 ft of station elevation. No temperatures are forecast
for 3,000 ft or within 2,500 ft of station elevation.
|
| TAFs |
|
This box displays the two most recent TAFs for the location you selected or the nearest reporting station.
The TAFs are in a decoded format.
|
| NWS Short Range Forecast Maps |
|
The maps forecast the evolution of major weather systems that will affect the continental US over the next
48 hours. The maps are issued twice a day.
|
| Symbols and Legends |
|
|
Area Forecasts
