Subj : Wx Terms (E)(4) To : All From : Daryl Stout Date : Sun Aug 06 2017 12:06 am Extreme Ultraviolet (EUV) A portion of the electromagnetic spectrum from approximately 100 to 1000 angstroms. Extreme Wind Warning Extreme Wind Warning (EWW) inform the public of the need to take immediate shelter in an interior portion of a well-built structure due to the onset of extreme tropical cyclone winds. An EWW for extreme tropical cyclone winds should be issued when both of the following criteria are met: a. Tropical cyclone is a category 3 or greater on the Saffir Simpson hurricane scale as designated by NHC, CPHC or JTWC. b. Sustained tropical cyclone surface winds of 100 knots (115 mph) or greater are occurring or are expected to occur in a WFO's county warning area within one hour. Extremely Low Frequency (ELF) That portion of the radio frequency spectrum from 30 to 3000 hertz. EXTRM Extreme EXTSV Extensive Eye The relatively calm center in a hurricane that is more than one half surrounded by wall cloud. The winds are light, the skies are partly cloudy or even clear (the skies are usually free of rain) and radar depicts it as an echo-free area within the eye wall. Eye Wall It is an organized band of cumuliform clouds that immediately surrounds the center (eye) of a hurricane. The fiercest winds and most intense rainfall typically occur near the eye wall. VIP levels 3 or greater are typical. Eye wall and wall cloud are used synonymously, but it should not be confused with a wall cloud of thunderstorm. --- þ Synchronet þ The Thunderbolt BBS - wx1der.dyndns.org .