My Barometer Rules

My Barometer Rules Short Guide
with rules for thunderstorms, Strong Winds and Gales from the Secret Law of Storms

Last 3 hours
▲10 mb Gale Warning (34 – 47 knots)
▲6 mb Strong Wind Warning (26 – 33)
▲1.1-2.7 poorer weather to come
( > 1015 mb)
▼1.1-2.7 rain & wind ( < 1009 mb)
▼4 mb storm ( < 1009 mb)
rain & wind (1009 - 1023 mb))
▼6 mb storm with a Strong Wind Warning
( <1009 mb)
▼7 mb firestorm conditions if fire exists &
( < 990 mb) & ( > 40 oC) sustained
▼10 mb storm with a Gale Warning
( <1009 mb)
Severe Thunderstorm Warning
Last 3 hours ▼4 mb Last 12 hours ▼8 mb
(Pressure < 1005 mb)
Anytime in Storm Season (Tropics)
steady Tropical Cyclone Early Warning if continuously steady for 6 hours
▼5 mb tropical revolving storm (for fall below tropical seasonal average)
More Barometer Rules

Last 3 hours < 1009 mb 1009 – 1018 mb 1019 – 1023 mb > 1023 mb
rising clearing and colder no change, except poorer weather to come for 1.1 – 2.7 mb and > 1015 mb no changeexcept poorer weather to come for rise of 1.1 mb – 2.7 mb fair weatherexcept poorer weather to come for rise of 1.1 mb – 2.7 mb
steady clearing and colder no change fair with slight temperature change fair with no marked temperature change
1.1 – 2.7 mb rain& wind no change no change and rain within 24 hours fair and slowly rising temperature
4 mb storm rain & wind rain& may get increasing wind speed and temperature warming trend
10 mb storm and Gale
  • Wind speed scale applies to rise or fall in pressure
  • A 3 hPa fall is the threshold for a thunderstorm. Here we use a 4 hPa fall so as to provide a margin of comfort for prediction purposes.
  • www.worldstormcentral.co/law of storms/secret law of storms.
  • a storm typically requires pressure to be less than 1009 mb
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