Monday, February 27, 2012

FEBRUARY 19-26, 2012 - WHERE IS THE NORTH ATLANTIC OSCILLATION HEADED?

official product of... New England NAO
Ensemble Mean NAO Outlook
  The North Atlantic Oscillation (NAO) GFS (MRF) - Ensemble Indice Forecast from NOAA's Climate Prediction Center (CPC) is currently very weakly Positive. The GFS Ensemble Indice Forecast indicates that the NAO will be neutral to very weakly Negative February 28-29. The Ensemble Indice Forecast indicates the NAO will be neutral to weakly Positive March 1-7. The GEFS later indicates that the NAO will be weakly Positive... trending neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern. 
  The NAO - Operational GFS Indice Forecast from (CPC) is also currently very weakly Positive. The Operational GFS Indice Forecast indicates that the NAO will be neutral to very weakly Negative February 28-29. The Operational Indice Forecast indicates the NAO will be neutral to weakly Positive March 1-7. The GFS later indicates that the NAO will be weakly Positive... trending neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern. 

Ensemble Mean AO Outlook
  The Arctic Oscillation (AO) GFS (MRF) - Ensemble Indice Forecast from (CPC) is currently very weakly Positive. The GFS Ensemble Indice Forecast indicates that the AO will be neutral to very weakly Negative February 28-29. The Ensemble Indice Forecast indicates the AO will be neutral to weakly Positive March 1-7. The GEFS later indicates that the AO will be weakly Positive... trending neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern.
  The AO - Operational GFS Indice Forecast from (CPC) is currently very weakly Positive. The Operational GFS Indice Forecast indicates that the AO will be neutral to very weakly Negative February 28-29. The Operational Indice Forecast indicates the AO will be neutral to weakly Positive March 1-7. The GFS later indicates that the AO will be increasingly Positive... then trend neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern. 

Ensemble Mean PNA Outlook
  The Pacific-North American Oscillation (PNA) GFS (MRF) - Ensemble Indice Forecast from (CPC) is currently neutral. The GFS Ensemble Indice Forecast indicates that the PNA will be neutral to very weakly Positive February 28-29. The Ensemble Indice Forecast indicates the PNA will be neutral to weakly Negative March 1-7. The GEFS later indicates that the PNA will be very weakly Negative... trending neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern.  
  The PNA Operational GFS Indice Forecast from (CPC) is currently neutral.  The Operational GFS Indice Forecast indicates that the PNA will be neutral to very weakly Positive February 28-29. The Operational Indice Forecast indicates the PNA will be neutral to weakly Negative March 1-7. The GFS later indicates that the PNA will be increasingly Negative... trending neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern. 

  
  The Eastern Pacific Oscillation (EPO) GFS (MRF) - Ensemble Indice Forecast from NOAA's Earth System Research Laboratory (Physical Sciences Division) and NCEP, is currently neutral. The GFS (MRF) Ensemble Indice Forecast indicates that the EPO will be weakly Positive.. trending increasingly Positive March 1-7. This indice forecast then indicates that the EPO will be weakly Positive to neutral March 8-12.
  The Western Pacific Oscillation (WPO) GFS (MRF) - Ensemble Indice Forecast from NOAA's ESRL/PSD and NCEP, is currently neutral. The GFS (MRF) Ensemble Indice Forecast indicates that the WPO will be weakly to Moderately Positive March 1-7. This indice forecast then indicates that the WPO will be weakly Positive to neutral March 8-12.

Ensemble Mean AAO Outlook
  The Antarctic Oscillation (AAO) GFS (MRF) - Ensemble Indice Forecast from (CPC) is currently very weakly Negative. The GFS Ensemble Indice Forecast indicates that the AAO will be very weakly Negative February 28-29. The Ensemble Indice Forecast indicates the AAO will be neutral to very weakly Positive March 1-7. The GEFS later indicates that the AAO will be very weakly Negative... trending neutral March 8-14. 
NOTE: Indice Forecasts have been "modified," due to Forecaster's understanding of the "Current" Longwave pattern. 

 Indice Forecasts are for Extended & Long Range trends only, and are not meant to be taken verbatim. Please consult NWS Albany, N. Y. / NWS Taunton, or the NWSFO covering your region... for official short-term regional zone forecasts.   


EXTENDED OUTLOOK: Weak blocking over southeastern Canada in association with a brief short-lived -AO & -NAO influence, will allow for coastal redevelopment of low pressure on Wednesday, February 29. My initial timing of this potential deviation within the overall longwave pattern, was slightly off. However, this system has the potential to be interior New England's first moderate snowfall to this-point (especially over western & parts of northern New England)... of the meteorological 2011-12 Winter season. Due to progression of the Phase 2-5 Madden Julian Oscillation (MJO) wave in the equatorial Pacific, the pattern will again become progressive... with a return to an intense Zonal flow of Pacific origin, across North America. Temperatures will be seasonal to slightly above normal March 1-4, allowing for milder systems to effect the region... as the upper-steering of the 500-millibar Height Pattern shifts the existing Polar Vortex over northwestern Canada. This pattern will promote a re-establishment of the +AO & +NAO influence, as temperatures rise to well above normal levels in New England... March 5-12. 

LONG RANGE THOUGHTSAs the tropical intraseasonal oscillation, MJO wave progresses through phases 3-5... a strong Pacific jet-stream (in association with a +EPO pattern) will be the dominant feature. Of note, research has shown that the initial effects of a solar maximum are first observed at the equator... then expand north & south in-latitude. This is important to consider due to a highly active MJO influence (over the equatorial Pacific) for much of the Northern Hemisphere's cold season, which could be connected to the current observed solar maximum... in association to the
9-11 year Schwabe Cycle. The overall state of the
El Nino Southern Oscillation (ENSO) is also effected by this factor, as Pacific sea surface temperatures rise... with the establishment of weak El Nino conditions (as we enter the Northern Hemisphere's warm season).
 As for the extended & immediate long range, the current MJO wave will continue to progress through phase 5... and enter phase 6 during the second week of March. This will promote a re-establishment of the Negative EPO Ridge over the east-central Pacific... which could encourage the AO & NAO to briefly fall Negative around March 14-16.    


Prepared by: Daniel Viens, of... 

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