Sunday, February 20, 2011

FEB. 20, 2011 - WHERE IS THE NORTH ATLANTIC OSCILLATION HEADED?


"NEW ENGLAND & THE NORTH ATLANTIC OSCILLATION" WEEKLY INDICE REVIEW

Ensemble Mean NAO Outlook
  The NAO GFS (MRF) - Ensemble Indice Forecast from NOAA's Climate Prediction Center (CPC) is currently very weakly Negative. The GFS Ensemble Indice Forecast indicates that the NAO will become weakly Negative by the end of this month. The GFS Ensemble Indice Forecast then brings the NAO neutral to increasingly Positive around the first week of March.
  The NAO - Operational GFS Indice Forecast from (CPC) is also currently very weakly Negative. The Operational GFS Indice Forecast indicates that the NAO will become neutral by the end of this month. This indice forecast then indicates that the NAO will remain neutral to very weakly Positive around the first week of March.

Ensemble Mean AO Outlook
  The Arctic Oscillation (AO) GFS (MRF) - Ensemble Indice Forecast from (CPC) like the NAO, is currently very weakly Negative. The GFS Ensemble Indice Forecast indicates that the AO will become neutral to weakly Positive by the end of February. This indice forecast then brings the AO increasingly Positive around the first week of March.
  The AO - Operational GFS Indice Forecast from (CPC) is currently very weakly Negative. The Operational GFS Indice Forecast indicates that the AO will become neutral to weakly Positive by the end of February. This indice forecast also brings the AO increasingly Positive around the first week of March.

 Ensemble Mean PNA Outlook
  The Pacific-North American Oscillation (PNA) GFS (MRF) - Ensemble Indice Forecast from (CPC) is currently weakly Negative. The GFS Ensemble Indice Forecast indicates that the PNA will weaken in a Negative state by the end of  February. This indice forecast then appears to bring the PNA increasingly Negative around the first week of March, but later indicates pronounced weakening.
   The PNA - Operational GFS Indice Forecast from (CPC) is also currently weakly Negative. The Operational GFS indicates that the PNA will briefly weaken in a Negative state by the end of February. This indice forecast then appears to bring the PNA increasingly Negative around the first week of March.  
  The Eastern Pacific Oscillation (EPO) GFS (MRF) - Ensemble Indice Forecast from NOAA's Earth System Research Laboratory (Physical Sciences Division) and NCEP, is currently weakly Negative. The GFS (MRF) Ensemble Indice Forecast indicates that the EPO will become moderately Negative by the end of  February. However, this indice forecast indicates that the EPO will weaken in a Negative state and become neutral to very weakly Positive around the first week of March.
   The Western Pacific Oscillation (WPO) GFS (MRF) - Ensemble Indice Forecast from NOAA's ESRL (PSD) and NCEP, is currently very weakly Negative. The GFS (MRF) Ensemble Indice Forecast indicates that the WPO will become weakly to moderately Negative by the end of February. This indice forecast later indicates that the WPO will remain Negative, but weaken slightly around the first week of March.

Ensemble Mean AAO Outlook
  The Antarctic Oscillation (AAO) GFS (MRF) - Ensemble Indice Forecast from (CPC) is currently very weakly Positive. The GFS Ensemble Indice Forecast indicates that the AAO will become neutral by the end of February. This indice forecast then appears to bring the AAO increasingly Positive around the first week of March.


EXTENDED OUTLOOK:  I am focusing on the WPO & EPO for the Extended Outlook, due to important trends with these indices. The EPO is currently weakly Negative and will become increasingly Negative during the extended time frame. The WPO is currently very weakly Negative and will also become increasingly Negative during the extended period. This means significant changes have occurred over the Gulf of Alaska and eastern Pacific. As the EPO (WPO) ridge intensifies and the Indice becomes weakly to moderately Negative, heights will rise over western North America.
I personally believe that the PNA will weaken toward neutral around Feb. 26, as a result of intense amplification over the eastern Pacific.These changes will briefly allow for an increasingly Negative AO & NAO, to the east of the strengthening eastern Pacific (West coast) ridge around Feb. 26 to March 3. During this time-frame is the strongest probability of below normal temperatures and East coast cyclogenesis or storms for the season, as we Enjoy the Last Punch - of Winter in New England!

LONG RANGE THOUGHTS: Even though La Nina continues to weaken and the Madden Julian Oscillation (MJO) is non-active, changes will still take place. The "east-based" Negative NAO (allowing for seasonal temperatures in New England) will weaken significantly after loosing Teleconnection support around March 4-7, then completely absorbed by the Polar Vortex (PV) as it shifts to the North. This will be the exit of the Winter Season 2010/11, right before our eyes. By March 8-16 temperatures will be seasonal to above normal as the westerlies drive the Pacific jet-stream across North America.

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