Weather Outlook for September 11
Posted: September 11, 2012
A cold front will cross the region later Saturday and early Sunday accompanied by a broken band of showers so that not all areas will receive rain. A turn to seasonably mild weather is expected during the first couple of days next week before a stronger disturbance arrives at mid-week accompanied by more widespread showers, some with heavy rain. A cool snap is likely at the end of next week, though no widespread frost is expected.
While the Tropics are likely to quiet down for the next two weeks, a tug of war in sea surface temperature contrasts is building in the Pacific. This difference between warming in the equatorial waters (El Nino) and cooling in the north Pacific (known as the PDO) has cast even greater uncertainty on the seasonal forecasts, especially for the upcoming winter. At this time, it appears that the El Nino will peak early and be moderate to weak, so that the cool waters in the north Pacific should play a dominant role in the seasonal anomalies for eastern North America. If this plays out, then a milder than average winter (Dec-Jan-Feb) is likely with above average precipitation near the Great Lakes.
- Pennsylvania State Climatologist