Sunday, October 21, 2012

Cooler, Stormier Pattern Comes After Brief Warm-Up

ECMWF on the left, GFS on the right.
Models are indicating that a cooler and stormier pattern will emerge following the warm up that will strike in the first half of this week.

Above is the ECMWF and GFS 8-10 day 500mb height anomaly forecasts. Blue areas show stormy areas, while red portions of the charts indicate the presence of a high pressure system. The deeper a color is, the stronger its respective apparatus is.

The GFS and ECMWF are different in their forecasts of the 8-10 day period, with the GFS keeping a very stormy pattern ongoing across the northern US. The ECMWF is stormy in the East, but holds a ridge in the West. I believe that the ECMWF is underestimating its forecast- a positive PNA pattern like the one shown on the left creates multiple disturbances across the East, something the ECMWF is showing in its regular forecasts but not here. I think the GFS is on track with a stormy pattern in the East, but is not including the positive PNA that will likely develop after this warm up.

Temperatures will likely plummet towards the end of the week as models are showing what could be a very strong disturbance bringing very cold weather into the heart of the nation.


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