Fire watches and warnings

Conditions across the Inland Northwest continue to be drier than normal. For the first half of June, only 0.15 inches of rain has fallen at Cliff Harris’s station in Coeur d’Alene with 0.18 inches in Spokane. The normal June precipitation for Coeur d’Alene is 1.93 inches, and based on the long-term forecast charts, it looks like another month with below normal precipitation.

The dry and windy weather across the region last week helped to spread a disastrous fire in the Spokane area. As of the weekend, 15 homes in Spokane were heavily damaged or destroyed by Upriver River in the Beacon Hill and Northwood area of Spokane.

The latest wildfire forecast has above normal potential for fires across eastern Washington from now through September. In North Idaho, above normal potential for wildfires is expected in July and August, returning to near normal in September.

An article from the U.S. Forest Service illustrates the types of watches and warnings issued for wildfires. For example, to provide advance notice of potential fire weather threats, the National Weather Service will issue watches and warnings for potential fires, especially at this time of year. These watches alert fire and land management agencies that Red Flag Warning conditions may develop beyond the first forecast period, which is generally 12 to 48 hours in advance. In some cases, a Fire Weather Watch may be issued up to 72 hours before the expected event when forecasters have a high degree of confidence with the developing conditions. The Fire Weather Watch remains in effect until it expires, is canceled, or is upgraded to a Red Flag Warning if critical fire weather conditions become more certain.

Red Flag Warnings are also issued by the National Weather Service to inform the public, firefighters, and land management agencies that conditions are very favorable for wildland fire combustion, and rapid spread. These warnings were issued last week across eastern Washington due to the dry and windy conditions. Often during drought conditions, when humidity is very low, and especially when there are high or erratic winds which may include lightning as a factor, the Red Flag Warning becomes a critical statement.

Extreme Red Flag Warnings or Particularly Dangerous Situations (PDS) may also be issued. In 2019, the National Weather Service introduced an enhanced version of Red Flag Warnings, called Extreme Red Flag Warning. This warning means that conditions for fire growth and behavior are extremely dangerous due to a combination of very strong winds, very low humidity, long duration of expected conditions, and very dry fuels.

Across the Inland Northwest, Red Flag Warnings are common enough that residents often see multiple warning events each summer. During severe fire years, warnings were issued repeatedly as hot, dry, windy conditions developed. Most Red Flag Warnings occur between July and September, which is the peak fire season.

According to an article on “A Brief History of Signal Flags” from the National Weather Service Heritage, the origins of weather warning flags in the United States go back to the Army Signal Service. In 1860, General Albert Myer developed a visual communications system called "wig-wag" signaling, which used flags to send messages. When he took charge of the Signal Service's meteorological operations in 1870, flags became a tool for communicating weather information.

The first official weather signal flag was introduced in October 1871. By the 1880s and 1890s, hundreds of flag stations across the country displayed forecasts using combinations of symbols that indicated fair weather, precipitation, temperature changes, and later wind and hurricane warnings. Railroads also helped spread forecasts by displaying signals on train cars and using whistle codes.

When the Signal Service transferred weather responsibilities to the U.S. Weather Bureau in 1891, the flag system continued and evolved. However, as newspapers, mail service, radio, and eventually television became widespread, the importance of weather flags declined. The Weather Bureau began phasing them out in 1927, though some communities continued using them into the 1940s and 1950s. The modern Red Flag Warning was adopted by fire-weather forecasters in the United States during the 1960s to alert firefighters and land-management agencies that weather conditions were favorable for rapid wildfire ignition and spread.

As I mentioned earlier, a new El Nino has formed in the waters of the south-central Pacific Ocean and is still expected to be one of the strongest in history by late this year. With the warming of ocean waters, conditions across the Inland Northwest are expected to be warmer and drier than normal through July. However, as the sub-tropical jet stream gains strength, which is often the case during an El Nino event, some of that moisture expected over California by the fall and winter season could be directed to the north into our region. There is the possibility of this scenario developing by September. With an El Nino, the chances for near to above normal snowfalls in our region are low. But there are no guarantees, so stay tuned.

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Contact Randy Mann at [email protected].