[su_note note_color=”#d9f2da”]THURSDAY PM UPDATE: Today’s models continue with the increased likelihood of thunderstorms and showers Saturday afternoon.  The chance of showers and thunderstorm remain high Saturday night through all of Sunday.  Lower chances of showers on Monday.[/su_note]

Sometimes the best weather forecast is not to provide specifics, but rather, to indicate  when there’s too much uncertainty to make a confident forecast.

Such is the case this weekend where uncertainty about the movement of moisture from a tropical system will greatly affect our weather.

The current picture is that light showers will move in sometime Saturday afternoon and that there’s a chance of some rain or showers to persist through Sunday and possibly even through Monday.

Greatest chance of heavy rain is in Delaware and Maryland, less to our north.

There are major differences in the models but perhaps the only agreement is that this Memorial Day Weekend will not feature bright blue skies or overwhelming sunshine.

I’ll take a more definitive stance on Friday.

The stalled front and the train of moisture and rain riding up from the Gulf of Mexico will continue into the weekend.

Reviewing the current model output, Saturday still appears to be cloudy with rain through the day.  High near 70.  It will be breezy.

The only hope for Saturday is that the models sometimes over-extend the period of rain. Not sure we count on this model tendency here.  

The rain moves out for Sunday and some sun is possible.  High upper 70s.

We have a very wet and unstable weather pattern setting up for much of this week.  Thunderstorms, some severe, are possible most days of the upcoming week.

Right now (Monday early evening), a severe line of thunderstorms is affecting Washington DC.  (Possibly adding more water to the “swamp” there.)

In all seriousness, the storms approaching DC are extremely fast moving (excess of 60 mph), appear as a ‘bow echo’ but almost take the form of something called a derecho.   I don’t usually focus on weather outside the PHL area, but this radar image is impressive, with likely tornados.   We may have similar weather late tomorrow afternoon.