Today's Featured Post: Updated Long Range Outlook Will be Issued Wednesday at 4:30 PM Central Time.

Sunday, November 20, 2011

300,000 page views reached!

We broke the 300,000 page view mark this evening, only 20 months after this blog started business!
Thanks to anyone and everyone out there who has supported us through the months, and we look forward to blogging about weather for years to come!

18z GFS Renders 12z GFS Arctic Oscillation Forecast Void

The 12z GFS, which had been forecasting the Arctic Oscillation to extend its raging positive phase for the Arctic Oscillation, has been rendered void by the new 18z GFS as the 18z GFS has resumed the trend of nosediving the AO. You can see the marked areas of the 12z GFS and 18z GFS. We will continue watching the forecast, but this is the development as we see it right now.

2012-2013 Winter Sneak Peek Will Be Released Soon

Due to the overwhelming majority voting 'yes' in our poll asking if you would like a sneak peek of winter 2012-2013, we will be releasing one in the next several days.
Keep in mind it has a fair chance of being inaccurate, as we are over a year away.

12z GFS Comes In With Horrible Teleconnections; Defies Previous Model Runs

Today's new GFS has come in with a horrible concoction of teleconnections. We have edited the above map showing the Arctic Oscillation forecast from the past 4 GFS runs. The PNA is forecast to be negative, and the MJO will be moving through unfavorable phases.
All we will say at this point in time is to closely watch the 18z GFS. It will either validate this new forecast or void it.

+AMO/-PDO Provides Support To Major Trough Potential In Last Days of Nov.

Effects of PDO

Table 1: summary of Pacific and North American climate anomalies associated with extreme phases of the PDO.
climate anomalies
Warm Phase PDO
Cool Phase PDO
Ocean surface temperatures in the northeastern and tropical Pacific
Above average
Below average
October-March northwestern North American air temperatures
Above average
Below average
October-March Southeastern US air temperatures
Below average
Above average
October-March southern US/Northern Mexico precipitation
Above average
Below average
October-March Northwestern North America and Great Lakes precipitation
Below average
Above average
Northwestern North American spring time snow pack and water year (October-September) stream flow
Below average
Above average
Winter and spring time flood risk in the Pacific Northwest
Below average
Above average


Joe Bastardi, former Chief Long Range Meteorologist at Accuweather, has put up a message indicating that a +AMO/-PDO would help the potential for the theory of a major trough to hit the East/North US going into the last few days of November. You can see the differences between a warm PDO and negative PDO in the columns above, thanks to the University of Washington.
We are currently in a Cold PDO phase and a warm AMO phase. These indices change on a multidecadal basis- every couple decades. Since the mid 1990s, the AMO has been on a mainly positive streak. However, it is less positive than last year. During the warm phase of the AMO, temperatures across North America are above average, as shown by this map below thanks to Intellicast.
Since we are in a less positive phase than last year, it is possible that global temperatures may be slightly cooled from last year, in addition to low sunspots.
We will have more information on the trough as we come closer to the date.