Tide and Water Level Data 



90. Tide height values and water levels due to predominantly astro- 

 nomical forces of the Sun and Moon are discussed first in this section, 

 followed by a discussion of the extreme water levels which were particularly 

 influenced by meteorological conditions. All tide heights are referenced to 

 the local NGVD of 1929, unless otherwise specified. Appendix D contains 

 hourly water level data for storm dates during 1981. Monthly and annual tide 

 statistics for 1981 are shown in Table 8, with previous years' means and 

 extremes included at the bottom for comparison. Tides at the FRF are semidi- 

 urnal, and the mean tide range for 1981 was 101 cm. MSL, the average of all 

 tide heights during the year, was +9 cm. MHW was +59 cm, and MLW was -42 cm. 

 The mean tide statistics for 1981 were very nearly the same as those for 

 previous years. 



Table 8 



1981 Monthly, 1979, 1980, and 1981 Annual, and 1979-1981 Cumulative 

 Tidal Means and Extremes at Seaward End of FRF Pier, cm* 



Monthly for 1981 



MHW** 



MTL 



MSL 



MLW 



MR 



EH 



Date 



EL 



Date 



Jan 



48 



-1 



-1 



-50 



98 



85 



17 



-81 



20 



Feb 



44 



-7 



-7 



-58 



102 



77 



21 



-89 



6 



Mar 



56 



5 



5 



-45 



101 



106 



6 



-73 



15 



Apr 



43 



-9 



-9 



-60 



103 



80 



20 



-110 



5 



May 



64 



12 



13 



-40 



104 



115 



4 



-66 



4 



Jun 



60 



8 



8 



-44 



103 



126 



30 



-68 



4 



Jul 



60 



9 



10 



-42 



102 



95 



1 



-77 



29 



Aug 



69 



19 



19 



-32 



102 



140 



20 



-69 



16 



Sep 



72 



22 



22 



-28 



100 



115 



17 



-64 



15 



Oct 



66 



17 



16 



-33 



99 



125 



13 



-63 



21 



Nov 



67 



18 



19 



-32 



99 



149 



13 



-65 



9 



Dec 



55 



6 



6 



-44 



99 



113 



11 



-81 



17 



Annual 





















1981 



59 



8 



9 



-42 



101 



149 



Nov 



-110 



Apr 



1980 



59 



8 



8 



-43 



102 



118 



Mar 



-119 



Mar 



1979 



60 



9 



9 



-43 



103 



121 



Feb 



-95 



Sep 



Cumulative 





















1979-1981 



59 



8 



9 



-43 



102 



149 



Nov 81 



-119 



Mar 80 



All elevations refer to 1929 NGVD. 



Explanation of abbreviations: MHW = mean high water; MTL = mean tide 

 level; MSL = mean sea level; MLW = mean low water; MR = mean range; 

 EH = extreme high water; and EL = extreme low water. 



54 



