HIGH WATER OF ORDINARY SPRING TIDES (HWOST) - A tidal datum appearing in 

 some British publications, based on high water of ordinary spring 

 tides . 



HIGHER HIGH WATER (HHW) - The higher of the two high waters of any tidal 

 day. The single high water occurring daily during periods when 

 the tide is diurnal is considered to be a higher high water. 

 (See Figure A- 10.) 



HIGHER LOW WATER (HLW) - The higher of two low waters of any tidal day. 

 (See Figure A- 10.) 



HIGH WATER - See HIGH TIDE. 



HIGH WATER LINE - In strictness, the intersection of the plane of mean 



high water with the shore. The shoreline delineated on the nautical 

 charts of the U. S. Coast and Geodetic Survey is an approximation of 

 the high water line. For specific occurrences, the highest eleva- 

 tion on the shore reached during a storm or rising tide, including 

 meteorological effects. 



HINDCASTING, WAVE - The lose of historic synoptic wind charts to calculate 

 wave characteristics that probably occurred at some past time. 



HOOK - A spit or narrow cape of sand or gravel which turns landward at 

 the outer end. 



HURRICANE - An intense tropical cyclone in which winds tend to spiral 

 inward toward a core of low pressure, with maximum surface wind 

 velocities that equal or exceed 75 mph (65 knots) for several 

 minutes or longer at some points. TROPICAL STORM is the term 

 applied if maximum winds are less than 75 mph. 



HURRICANE PATH OR TRACK - Line of movement (propagation) of the eye 

 through an area. 



HURRICANE STAGE HYDROGRAPH - A continuous graph representing water level 

 stages that would be recorded in a gage well located at a specified 

 point of interest during the passage of a particular hurricane, 

 assuming that effects of relatively short-period waves are elimi- 

 nated from the record by damping features of the gage well. Unless 

 specifically excluded and separately accounted for, hurricane surge 

 hydrographs are assumed to include effects of astronomical tides, 

 barometric pressure differences, and all other factors that in- 

 fluence water level stages within a properly designed gage well 

 located at a specified point. 



HURRICANE SURGE HYDROGRAPH - A continuous graph representing the differ- 

 ence between the hurricane stage hydrograph and the water stage 

 hydrograph that would have prevailed at the same point and time 

 if the hurricane had not occurred. 



A-16 



