Strong Negative North Atlantic Oscillation Ahead!

 Get ready for a major Northeast Storm centered on November 23^rd.

Fig. 1: Today’s North Atlantic oscillation forecast indicates a strong negative phase develops for Thanksgiving week.

Fig. 2: -NAO intensity at or stronger than -2.0 produces cold (and snow) across Southern Canada and across the Northeast U.S.

Fig. 3-4: GFS and ECM depiction of a Nov. 23 Nor’easter.

Fig. 5: Much warmer than normal SSTA off the Northeast Coast certainly validates the low-pressure forecast for this storm and most likely the farther west track indicated by ECM

Discussion: Today’s North Atlantic oscillation (NAO) forecast intensifies into the strong negative phase for next week signaling a high latitude blocking pattern forcing a Northeast U.S. storm featuring extreme intensity. Both the GFS and ECM project 970 MB low-pressure which could produce another intense wind event for the northern Mid-Atlantic and New England States for early-to-middle of next week, just before the Thanksgiving Holiday.

The -NAO forecast is near or stronger than -2.0 (Fig. 1) which historically represents a cold and snowy onslaught across southern Canada into New England (Fig. 2). The snowy pattern across Southern Canada is aligning as a cold air trajectory across that increasing snow cover is likely into next week. The push of that chilly air across the much warmer than normal ocean water will lead to an explosive low-pressure system. Both GFS and ECM project a 970 MB low-pressure area midday next Tuesday (Nov. 23) but with large differences in the positioning. GFS has the storm near Nantucket (Fig. 3) while ECM has the storm in New Jersey (Fig. 4). Given the very warm waters offshore (Fig. 5) the location of greatest baroclinicity is likely farther west than normal and closer to the land mass favoring the ECM over GFS.

The ECM solution indicates a massive high wind event for the northern Mid-Atlantic and south/east portions of New England. Due to the warm water the precipitation type is mostly heavy rain. New York State is hit with a heavy snowstorm and a large area of mixed precipitation affects far western New England/eastern New York with heavy snow in the northern New England mountains.  The GFS solution is colder…plenty of wind and snows farther east.