Active Pattern Set to Continue into Mid Month
Tropics & The Pole Initially Conflict
There were two assertions made by Eastern Mass Weather with respect to the month of February, and the fact that they have both come to fruition is making for some challenging forecasts with respect to storm tracks because they reality is that they both conflict with one another.
Maritime Continent Forcing to Remain Prevalent Throughout First Half of Month
Currently the MJO is in phase 6 and approaching phase 7 at a fairly strong amplitude, both of which tend to favor lower heights in the west and greater heights in the east.
Note the shift to the east of the east coast ridging and the building of higher heights in the west, which serves as a prelude to the changes that will grow more prevalent beyond mid month.
While intuitively one may suggest that this promotes in inland track of east coast cyclones, that is not always the case, as is the cast with storm number one on Tuesday.
Note that the system is forecast to pass south of the area and out to sea. despite the east coast ridge. However, if there were more of a trough on the east coast, the wave could potentially "dig" more, which could allow it to amplify and track further up the coast. Thus the more precise way to articulate this is that Maritime continent forcing is simply more unfavorable for major east coast winter storms because the east coast ridging that it promotes is hostile in a multitude of ways. However, tropical forcing does not operate in a vacuum, and there other global influences that can dictate the pattern. Namely, the higher latitudes.
Ensuing Polar Vortex Split Will Play A Role
In addition to a return to Maritime continent forcing and west coast troughing, the other Eastern Mass Weather postulation that is coming to fruition this month is a major disruption of the polar vortex, which will take place early this week.
Not only will the disjointed polar vortex lobe supply antecedent cold air masses in advance of storm systems, but it will also act to foster the development of higher heights around the pole, which will only grow more prominent and represent added resistance to inland tracks towards mid month. While this next storm system on Thursday is an example of Maritime continent forcing mitigating an east coast storm opportunity via higher heights allowing for a more inland track, the aforementioned antecedent cold will also be evident. There is likely to be a few inches of snowfall across at least the interior prior to ending as sleet and rain.
Cold will become more prevalent and there will be added resistance to inland tracks of low pressure systems as the month of progresses. A potentially major storm next weekend looks to at least deposit several inches of snowfall across the area prior to any mix or change to sleet and rainfall.
Beyond mid month tropical forcing will begin to augment the building of heights near the pole as the MJO approaches phase 8.
Stay tuned for First Call for the Thursday system tomorrow night and more update on the potential weekend system throughout the week.
