TEMPERATURES
PRECIPITATION
Long Range Forecast Discussion September 11-25
Models are in agreement on the longwave pattern for the period Sep. 11-15 in depicting a trough near the West coast, a flat ridge in the Plains and another trough off the East coast. Models and ensembles are in good agreement on the flow pattern forecast across North America for the Sep. 14-18 period. Models have a trough over the west coast and eastern Canada with weak ridge over the central and southern U.S. The 0Z operational ECMWF depicts the most amplified ridge. The operational 0Z and 6Z GFS depict the same features as their ensembles. The trough along the West coast will cause below normal temperatures for the Northwest and northern California. The ridge across the southern and central Plains will cause above normal temperatures across this region. Below normal temperatures are forecast along the much of the East coast. Below normal precipitation is forecast for much of the West. Above normal precipitation is forecast for the eastern gulf coast and the Southeast. Models and ensembles remain in good agreement with the 500-hpa height pattern for the Sep. 19-25 period. Models maintain a pattern similar to that in the previous period. However, height fields are expected to be weaker. Little change is expected in the temperature and precipitation anomalies.
500 PM EDT Wed. Sep. 8, 2010
http://www.jimmunleywx.com