BETHLEHEM, Pa. — That fall feeling has settled in, but the Lehigh Valley will get an early taste of winter overnight, as well.
The National Weather has issued a freeze warning in effect from 2 to 9 a.m. Thursday for Lehigh, Northampton, Berks, Carbon and Monroe counties.
Temperatures as low as 29 are expected, the warning says.
In the Allentown area, the forecast overnight low is 30 degrees. The last time the temperature bottomed out at 30 was back on March 26. The night before, temperatures were in the 20s.
The featured chart below presents the number of days from the first subfreezing temperature until the first sub-29-degree temperature, which is considered a killing frost. The slanted grid lines allow you to see the date on which the dots fall.
The freeze warning comes after another day where highs will be almost 10 degrees below normal, the weather service said in its latest forecast discussion.
That means temperatures generally will top off in the mid- to upper-50s throughout the region, and in the 40s in the southern Poconos.
“West to northwest winds will once again increase to 10 to 15 mph, with 15 to 20 mph gusts,” the discussion said.
Winds are expected to diminish after sunset, and skies are expected to be clear for the northwest half of the region, “resulting in strong traditional cooling conditions for the southern Poconos, northern New Jersey and the Lehigh Valley.”
Six of the past eight days have featured below-normal temperatures for the area, but we’ll see a big change by the weekend, forecasters say.
Speaking of dry conditions…
The Lehigh Valley has measured just 1/100 (0.01) of an inch of rain so far this month — the first measurable amount of rainfall reported by The National Weather Service, and just above a "trace" of rain.
For perspective, that would not leave puddles on the ground and would only slightly wet the surface.
As of Wednesday, our precipitation departure from normal stood at minus-2.19 inches for the month.
Since Sept. 1, the Allentown area has measured just 1.31 inches of rainfall, a departure from normal of 5.73 inches.
According to the weather service, Philadelphia’s last day of measurable rainfall was Sept. 28, making Tuesday the 17th consecutive day without it.
The record for the city since 1871 is 29 days, which ran from Oct. 11 to Nov. 8, 1874.
If the current forecast for no rain holds through next week, Philadelphia will be in at least the Top 10 driest stretches of days on record.
According to the U.S. Drought Monitor, it is extremely dry over a large majority of the contiguous 48 states.
In our region, modeled soil moisture is in the lowest 5% of historical occurrences on the DelMarVa Peninsula, southeastern Pennsylvania, southern New Jersey, and the northeastern half of Maine.
