1026.0-1 



1024.0- 



1022.0- 



g 1020.0- 



j| 1018.0- 



</) 



I/) 



U 



K 1016.0 

 Q. 



1014.0- 



1012.0 



1010.0 



YEAR MEAN.mb 



85 1016.6 



83-84 1016.9 



JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 

 MONTH 



Figure 4. Mean monthly atmospheric pressure 



Precipitation 



24. Precipitation is generally well distributed throughout the year, 

 averaging 104 cm annually. Precipitation from midlatitude cyclones 

 predominates in the winter, while local convection (thunderstorms) accounts 

 for most of the summer rainfall. 



Measurement instruments 



25. Electronic rain gage. A Belfort Instrument Company (Baltimore, Md.) 

 30-cm weighing rain gage, located near the instrument shelter 47 m behind the 

 dune, measured daily precipitation. According to the manufacturer, the in- 

 strument's accuracy was 0.5 percent for precipitation amounts less than 15 cm 

 and 1.0 percent for amounts greater than 15 cm. 



26. The rain gage was inspected daily, and the analog chart recorder 

 was maintained by the procedures listed in paragraph 19. 



27. Plastic rain gage. A Edwards Manufacturing Company (Alberta Lea, 

 Minn.) True Check 15-cm-capacity clear plastic rain gage with a 0.025-cm 



19 



