BETHLEHEM, Pa. — The National Weather Service forecast office covering the Lehigh Valley had a message Wednesday for readers of its area forecast discussion.
“The pleasant stretch of weather we encountered early in the week is beyond us,” meteorologist Joe DeSilva wrote.
After days of sun and warmth, mostly cloudy to overcast skies will shroud much of the area, with a very moist air mass in place.
That will set the stage for showers and thunderstorms expected to develop and approach from the southwest Wednesday night, DeSilva wrote.
Excessive rainfall risk
For most of the late evening to overnight period, light to moderate rain with embedded thunder is expected, giving way to spotty showers and storms by early Thursday.
But PWATS — or precipitable water values — also will be near or in excess of 2 inches during this time, the forecast discussion said.
PWATs measure the amount of water vapor contained in a column of air if it were to be condensed and collected.
As a result, the Weather Prediction Center has much of the forecast area, including the Lehigh Valley, within a marginal risk (1 out of 4) for excessive rainfall.
“Flash flooding does not appear to be a threat as ground soils are relatively dry and the storm motion is quick,” the NWS forecast discussion said.
EPAWA's 6/5 and week ahead outlook, covering:
— Bobby Martrich | EPAWA (@epawawx) June 5, 2024
■ Timing of the showers/thunderstorms Wednesday
■ Cold front quickly follows on Thursday afternoon
■ Updated weekend outlook...and it's looking better https://t.co/UahiiU3Eb0
In his latest video update, EPAWA meteorologist Bobby Martrich also emphasized any rainfall probably would be very late in the day, most likely during the evening and overnight hours.
“We’ll have some heavy rain possible in any of these storms that come through," Martrich said. "They’re going to be garden-variety otherwise.”
Another round on Thursday
Forecasters say guidance continues to highlight the likelihood of another round of showers and storms moving through Thursday afternoon into Thursday night.
Highs are expected to be in the low- to mid-80s, dependent on the amount of clearing.
Thursday night lows will finally be a little bit cooler, falling into the upper 50s to mid-60s across the region.
