Stormy Pattern Ahead

The Madden Julian Oscillation (MJO) index is entering phase three – favoring an amplifying trough of low pressure to set up shop across the Mid-Atlantic and New England states.  This trough (broad dip in the jet stream) will produce cooler than average temperatures along with the potential for three major storm systems to impact our area.  In addition to some moderate to heavy rainfall and the potential for some stronger/severe thunderstorms, the Appalachian mountains could receive some heavy, wet snow.

The next image shows the temperature anomalies in April which correlate with the eight phases of the MJO (notice how cold phase 3 is in the next image).

Below average temperatures are common in phase three of the MJO in March/April/May (MAM) across much of the United States, image below courtesy NOAA.

The latest European Forecast Model for the three storms (images courtesy Pivotal Weather)

Thursday:  The main threat will be for a widespread heavy rainfall event with upwards of one to possibly two inches falling across the region. Additionally, some embedded stronger storms are possible across central Virginia and any shift northward in the track of this storm system would increase the threat of stronger storms in the Washington Area.

Sunday: The main threat includes severe thunderstorms east of the mountains, high winds region-wide and heavy mountain snows.

Wednesday:  It’s too far to speculate on the details of this system, but as of now a line of strong to severe storms looks possible with more heavy mountain snows across Garrett county Maryland and portions of the West Virginia mountains.

The image below shows the very impressive trough (dip in the jet stream) indicative of blue and purple colors across the eastern seaboard during this time frame.

Enjoy the chilly sunshine on Wednesday, I’ll provide more updates as needed should the threat of severe weather increases to the immediate Washington Area.