BETHLEHEM, Pa. — The Lehigh Valley and much of the Mid-Atlantic are heading into winter without a clear signal on what the months ahead could bring.
The lack of clarity comes as forecasters at the National Oceanic and Atmospheric Administration’s Climate Prediction Center released their seasonal outlook.
Forecasters at the CPC say the region faces “equal chances” for above, near or below-normal precipitation from December through February — meaning the odds of any outcome are roughly even.
The outlook contrasts with more definitive outlooks elsewhere in the country, where the Pacific Northwest is likely to be wetter than normal and the southern U.S. is expected to be warm and dry.
La Niña advisory
The outlook comes as La Niña — a recurring Pacific Ocean climate pattern characterized by cooler-than-normal equatorial waters — begins to influence global weather.
La Niña tends to shift the jet stream northward, steering winter storms away from the southern states and leaving parts of the Mid-Atlantic caught between competing weather tracks.
For the Lehigh Valley and surrounding areas, it could translate into an unpredictable season: periods of rain or snow punctuated by stretches of milder, dry weather.
NOAA's temperature outlook tilts toward warmer-than-average conditions across much of the region, which could reduce snowfall and cause precipitation to fall as rain.
That could affect how much moisture manages to seep into the ground and recharge rivers and reservoirs.
The uncertain outlook has implications for ongoing drought conditions.
The entire Lehigh Valley is considered “abnormally dry,” according to the latest update from the U.S. Drought Monitor, while parts of the Mid-Atlantic — particularly in parts of Maryland and West Virginia — are in severe drought or extreme drought status.
Without a consistently wet winter, many areas will struggle to rebuild soil moisture heading into spring, experts say.
Drought could persist in many areas
NOAA’s seasonal drought outlook — a separate product from the winter outlook — suggests that existing dry areas in many parts of Pennsylvania are more likely to persist than worsen.
The website Drought.gov, which is the National Integrated Drought Information System, is not being updated during the government shutdown.
Data from the Northeast Regional Climate Center’s Climate Perspectives tool shows the past three months in the Lehigh Valley are its 12th driest on record, with a deficit of 7.19 inches of precipitation.
Entering Monday, the area had a year-to-date rainfall deficit of 6.50 inches.
For now, the takeaway from NOAA’s winter forecast is simple: Expect variability, and don’t count on guaranteed drought relief.
NOAA’s next update to the seasonal outlook is due in mid-November, when forecasters will have a better sense of how a developing La Niña pattern is shaping up and what it could mean for winter.
