Temps, Air Pollution Levels To Jump In The Hudson Valley

HUDSON VALLEY, NY — Air quality advisories go into effect overnight for the Hudson Valley as flash flood watches end, contributing to a forecast for a thick, hot, humid Monday.

When pollution levels are elevated, the New York State Department of Health recommends that you consider limiting strenuous outdoor physical activity. People who may be especially sensitive to the effects of elevated levels of pollutants include the very young and anyone with respiratory problems such as asthma or heart disease.

The best that can be said for Monday is that it'll be mostly sunny, and the humidity level will slide from 100 percent overnight to 50 percent in the afternoon before it rises again and a chance of thunderstorms returns.

That will give us limited time to dry out from the storm system that brought 24-hour flood watches to the region.

"In Putnam, Suffolk, and Westchester Counties, we've seen one and a half to two inches of rain per hour," Gov Kathy Hochul said in a storm briefing at 4 p.m. "But right now, in those areas, we've not seen significant or catastrophic flooding as we speak. And the good news is for those who are [without] power, we had 23,000 people [without] power since the beginning of this event. It is now down to 9,300. But if you're one of those 9,300 families without your power, it is a frightening time."

SEE: 16K Without Power Sunday AM In The Hudson Valley

Before 1 p.m. Sunday, the storms had dropped another 2 inches of rain on the already-saturated Hudson Valley (on July 9, the region received up to 8 inches of rain, and on Friday up to 3 inches) with more expected.

"Persistent downpours in areas like the Hudson Valley in New York and high elevations in Vermont mean the risk of new or worsening flooding in these areas is high, particularly in the beginning of the week," said Richard Perrins, AccuWeather digital journalist.

The storms halted operations Sunday afternoon at La Guardia, Newark and JFK airports, with hundreds canceled and more delayed, according to FlightAware.com.

Here's the next 48 hours at a glance, based on Larchmont:

The air pollution will be due in part to more toxic, acrid smoke from Canadian wildfires pushing its way east after creating unhealthy conditions in the Midwest.

Exposure can cause short-term health effects, such as irritation to the eyes, nose and throat, coughing, sneezing, runny nose and shortness of breath. Additional information is available on DEC and on DOH websites.

The poor air quality will be due to both ozone and PM2.5. The smoky and hazy sky in an otherwise mostly sunny, stagnant air mass can be very conducive for ozone production, state environmental officials said.

Individuals experiencing symptoms such as shortness of breath, chest pain or coughing should consider consulting their doctor.

There were 877 wildfires burning in Canada on Sunday, according to the Canadian Interagency Fire Centre.

Several blazes in British Columbia have produced smoke-infused storm clouds known as pyrocumulonimbus (pyroCb) in recent weeks, the NASA Earth Observatory reported. As of July 13, with about six weeks left in the Canadian fire season, atmospheric scientists with the U.S. Naval Research Laboratory had observed 90 pyroCbs in Canada and 104 worldwide in 2023. The previous records, both set in 2021, were 50 for Canada and 100 worldwide.

Here's the five-day forecast from the NWS based on Larchmont:

• Sunday night - Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm. Cloudy, then gradually becoming partly cloudy, with a low around 70. South wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
• Monday - Mostly sunny, with a high near 90. Light and variable wind becoming southwest around 6 mph in the afternoon.
• Monday Night - Widespread haze. Partly cloudy, with a low around 72. South wind 5 to 8 mph.
• Tuesday - A 50 percent chance of showers and thunderstorms. Widespread haze. Partly sunny, with a high near 89. Light southeast wind becoming south 6 to 11 mph in the morning.
• Tuesday Night - Partly cloudy, with a low around 68.
• Wednesday - Mostly sunny, with a high near 88.
• Wednesday Night - A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 30%.
• Thursday - A 30 percent chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 87.
• Thursday Night - A 30 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 69.
• Friday - A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 87.
• Friday Night - A 30 percent chance of showers. Mostly cloudy, with a low around 69.

SEE: HV Town-by-Town Rainfall Totals From Sunday's Severe Weather