Forecast for heavy rain, melting snowpack prompts region Christmas Eve flood watch
Any hopes for a white Christmas are pretty much dashed at this point — washed away, in fact, by a very rainy, windy and warm Christmas Eve forecast.
The potential for excessive rain and gusty winds prompted the National Weather Service in Mount Holly, New Jersey, to issue a flood watch for Lehigh, Northampton, Carbon, Berks and Monroe counties from Thursday evening through Friday morning.
Though Wednesday looks dry and uneventful, and Thursday morning will begin calmly, heavy rain is expected to move in from the west in the late afternoon ahead of a strong cold front. With the rain, temperatures will rise to the mid-50s, and winds could gust up to more than 30 mph. Wind gusts could reach 50 mph or more along the coast of the Jersey Shore.
“Just not a good day,” EdVallee of Empire Weather Consulting, which produces localized forecasts for The Morning Call, said in an online forecast.
The warm weather and 1-2 inches of rain would quickly melt away remaining snow on the ground, creating the potential for flooding, the NWSwarns, with the southern Poconos potentially seeing 2-3 inches of rain.
“The heaviest rain will fall over snowpack with as much as an inch of liquid equivalent rainfall, leading to rapid melting of the snow,” the NWSwrote in the advisory, adding flows in rivers and streams “may increase quickly and reach critical levels.”
That cold front will arrive sometime Friday, behind the rainy system, though it’s still uncertain when exactly, Vallee said.
Temperatures are certain to plummet back into the 30s Friday, likely freezing any standing water on pavement by midday, he said. Models disagree about what time the drop will occur.
But meteorologists agree that there is no winter precipitation — read, snow — expected with Thursday’s storm.
Instead, it will leave the Lehigh Valley with a relatively calm Christmas day, but with a possibility of 15 mph winds and icy roads.
After that, we’re in for a cold weekend.