27 results. (Showing 1 - 20)

1. F scale

2. Feeder Bands
Lines or bands of low-level clouds that move (feed) into the updraft region of a thunderstorm, usually from the east through south (i.e., parallel to the inflow). Same as inflow bands. This term also is used in tropical meteorology to describe spiral-shaped bands of convection surrounding, and moving toward, the center of a tropical cyclone.

3. Flanking Line
A line of cumulus or towering cumulus clouds connected to and extending outward from the most active part of a supercell, normally on the southwest side. The line normally has a stair-step appearance, with the tallest clouds closest to the main storm, and generally coincides with the pseudo-cold front.

4. flash flood statement
Used as a follow-up to Flash Flood Warnings and Watches. The statement will contain the latest information on the event.

5. flash flood warning
Signifies a dangerous situation where rapid flooding of small rivers, streams, creaks, or urban areas are imminent or already occurring. Very heavy rain that falls in a short time period can lead to flash flooding, depending on local terrain, ground cover, degree of urbanization, degree of man-made changes to river banks, and initial ground or river conditions.

6. flash flood watch
Indicates that flash flooding is possible in and close to the watch area. Those in the affected area are urged to be ready to take quick action if a flash flood warning is issued or flooding is observed.

7. flood potential outlook
Used to inform the public of the potential for heavy rain and/or large scale river flooding. Issued more than 12 hours in advance of a possible event.

8. flood stage
The level of a river or stream at which considerable inundation of surrounding areas will occur.

9. flood statement
Used as a follow-up to Flood Warnings and Watches. The statement will contain the latest information on the event.

10. flood statement (river)
Used to update and expand information in a river Flood Warning. May also be used in lieu of a Flood Warning if flooding is expected or imminent, but does not pose a threat to life and/or property.

11. flood warning
Issued for life/property threatening general flooding that occurs during or within 12 hours after heavy rainfall has ended. It could be issued for rural or urban areas as well as for areas along small streams and creeks.

12. flood warning (river)
Used to inform the public of long-term (more than 12 hours) flooding along major streams and rivers, which is a threat to life and/or property. Usually contains river stage forecast and crest information, and the history and impact of the flood.

13. flood watch
Indicates that flash flooding is a possibility in and close to the watch area. Those in the affected area are urged to be ready to take quick action if a flash flood warning is issued or flooding is observed. These watches are issued for rapid flooding that is expected to occur during or within 6 hours after heavy rain has ended.

14. fog
The visible aggregate of minute water droplets suspended in the atmosphere near the earth's surface. Essentially a cloud whose base is at the earth's surface.

15. Forecasts (Synonymous with predictions and outlooks)
A weather forecast, or prediction, is an estimation based on special knowledge of the future state of the atmosphere with respect to temperature, precipitation, and wind. Weather forecasts are now routinely provided for up to 14 days in advance and outlooks for seasonal and longer timescales.

16. Forward Flank Downdraft
The main region of downdraft in the forward, or leading, part of a supercell, where most of the heavy precipitation is. Compare with rear flank downdraft.

17. Fractus
Ragged, detached cloud fragments; same as scud.

18. freeze warning
Issued during the growing season when temperatures at/near the ground are expected to drop well below freezing (32F) over a widespread area for a significant amount of time, regardless of whether frost forms or not. Adjectives such as 'killing' or 'hard' will be used as appropriate.

19. freezing level
The altitude in the atmosphere where the temperature equals 32F.

20. freezing rain
Rain which falls as liquid then freezes upon impact, resulting in a coating of ice on exposed objects.