Pocket weather
from the 1998 International Marine Daybook and Nautical Desk Reference

Wind direction Barometer
reading
Barometer movement Weather outlook
 SW to NW 1023 / 30.2 Steady Continuing fair. Temperature remaining steady.
 SW to NW 1023 / 30.2  Slow fall Temperature rising slowly. Fair for 48 hours.
 SW to NW 1019 to 1023 / 30.1 to 30.2  Steady Stable temperature, remaining fair for 24 to 48 hours.
 SW to NW 1019 to 1023 / 30.1 to 30.2 Rapid rise Continuing fair but increasingly cloudy. Rain and cooler within 48 hours.
 SE to S 1019 to 1023 / 30.1 to 30.2  Slow fall Rain and warmer within 24 hours.
 SE to S 1019 to 1023 / 30.1 to 30.2 Rapid fall Wind and rain increasing within 12 to 18 hours.
 E to S 1009 / 29.8 or less Rapid fall Severe storm imminent, clearing within 24 hours. Winter: dropping temperatures.
 NE to E 1019 / 30.1 and higher  Slow fall Summer: light winds, rain within three days. Winter: rain within 24 hours. Slightly warmer.
 NE to E 1019 / 30.1 and higher Rapid fall Summer: rain within 24 hours. Winter: increasing rain or snow within12 hours.
 NE to SE 1019 to 1023 / 30.1 to 30.2  Slow fall Wind and rain increasing within 12 to 18 hours.
 NE to SE 1019 to 1023 / 30.1 to 30.2  Rapid fall Wind and rain increasing within 12 hours.
 NE to SE 1016 / 30.0 and less  Slow fall Extended period of rain 1 to 3 days or more.
 NE to SE 1016 / 30.0 and less Rapid fall Strong winds and rain imminent. Clearing and cooling within 36 hours.
 N to E 1009 / 29.8 and less  Rapid fall Northeast gale and heavy rain imminent. Winter: Snow and extended colder weather.
 S to SW 1016 / 30.0 and less Slow rise Clearing within a few hours. Fair weather for several days.

A rapid rise or fall is one in which barometric pressure changes at a rate of 1 millibar or 0.03 inches every three hours or less.


Wind Chill

Wind Chill (F) = 35.74 + 0.6215T - 35.75*(V0.16) + 0.4275*T*(V0.16)

Where T=Air Temperature (F)  V=Wind Speed (mph) at standard 33 ft. Wind speed at 5 ft. (face level) is approximately (2/3 * V)