Wildfires in New England

By Francis Tarasiewicz

My last blog was about an extreme flash flood event in southwestern Connecticut and so you can probably understand my feelings of irony as I write a blog about recent drought and wildfires in the Northeast and New England.

One of the many symptoms of climate change is an accelerated hydrologic cycle. Increased temperatures allow the atmosphere to hold more moisture and, so when it rains and meteorological conditions are just right, totals can be extreme. On the other hand, warmer than average temperatures can allow for greater rates of soil and plant moisture evaporation. This can lead to rapid onset or intensification of dry conditions, or flash drought.

If you live anywhere in New England and your lawn is a brown crisp of its former self and your town has enacted currently under a burn-ban you have likely come to know what it’s like to experience a flash drought.

So, how did we get here? After all, we had an extremely wet 2023 and start of 2024. Let’s talk about how persistent high pressure and an exceptionally dry and warm airmass play their parts.

The summer of 2024 will be remembered as a wet one, although nowhere near as wet as the previous year’s summer.

Part of the reason behind this summer’s frequent deluges was a weak trough or dip in the atmosphere across the Upper Midwest and portions of New England. This amorously low area of atmospheric heights allowed for a prolonged stretch of active weather and numerous severe weather outbreaks and rainstorms across the eastern third of the US.

The pattern began to change as September began and completely flipped by mid-month. A strong ridge of higher than normal heights replaced the trough and only got more intense with time. While the axis of highest pressure was centered over the upper Great Lakes, surface high pressure frequently moved east into the Northeast as a strong zonal (west to east) flow kept reinforcing high pressure. Outside of a few transient cold fronts high pressure remained as the dominant weather maker (trust me it was quite boring even at the Home of the World’s Worst Weather). In some cases areas further south weren’t even lucky enough to receive the pitiful rainfall totals from those passing fronts.

The days passed, high pressure persisted, and the ground continued to get drier. Despite an anomalously wet year, months of 0-5% of normal rainfall totals were taking their toll. The rainfall deficit became a soil moisture deficit as September rolled into October. Spooky season saw soil moisture anomalies between 2 and 5 inches below levels recorded at the end of August.

Then the brush fires started.

The rainless cold fronts I mentioned earlier brought dry northerly and northwesterly winds. All that is needed is a spark. As a result, there have been numerous days where the National Weather Service has issued Red Flag Warnings for much of New England. These fire weather days require a unique combination of relative humidity values at or below 15 percent, and sustained surface winds or frequent gusts of 25 mph or greater.

Since 2004, New Hampshire has only ever had 80 Red Flag Warnings issued. In contrast, Texas takes the crown with 3393 issued over the last 20 or so years. This means that fire weather on the east coast (outside of Florida) is fairly rare. Looking at the map of Red Flag Warning issuance since 2004 you can make out the influence of moisture availability from the Gulf of Mexico. An active storm track also plays a role in limiting our fire season to a couple of weeks in late spring. Most states besides Florida east of the Mississippi river have had considerably less warnings issued when compared to their western counterparts. Vermont has had the lowest total of 33.

By Halloween one of these fire weather warnings unfortunately ended up verifying. What began as a small brushfire near the Craigmeur Recreation Complex in northern New Jersey quickly grew into a bona fide 140-acre wildfire. The fire grew so intense that its heat signature was visible from the shortwave infrared channel on the GOES-16 satellite. Thankfully, that fire has been largely contained as of the writing of this blog but dry conditions are expected to remain through at least the next week.

Fire weather risks will likely continue through the foreseeable future so here are some tips from the Red Cross to prevent fires before they can get started.

Campfires and Bonfires

• Only start a campfire or bonfire in an appropriate fire pit, cleared of all vegetation and ringed by stones.
• Never leave a fire unattended, such as overnight.
• Always make sure your fire is completely doused with water and smothered with dirt before leaving.
• Don’t start a fire on a windy day. Save it for another time.

Smoking

• Dispose of used matches and butts in a closed container or cup of water.
• Keep lighters and matches out of the reach of children.
• Yard Waste or Rubbish Burns
• Only burn yard waste or rubbish in a 50 gallon drum or fire pit (see campfire section for fire pit tips).
• Never leave a fire unattended.
• Always make sure your fire is completely doused or smothered with dirt before leaving.
• Don’t burn yard waste or rubbish unless it’s allowed by your municipality.
• Don’t burn anything highly combustible, including paper or fabric soaked in oil or gasoline.
• Don’t start a burn on a windy day. Save it for another time.

Fireworks

• Have a bucket of water, garden hose or fire extinguisher handy. Consider wetting down the surrounding grass and other vegetation before lighting your fireworks.
• Never let children use fireworks, sparklers or fire crackers unsupervised.
• Don’t light fireworks on windy nights.
• Douse used fireworks with water to make sure they are completely extinguished.

Cars, Tools & Other Combustion Engines

• Don’t park a hot car or other machine in dry grass.
• Don’t allow gasoline or motor oil to spill on grass or other vegetation.
• Tractors, off-road vehicles and equipment being used in wooded areas, such as chainsaws, must have spark arrestors.