6:45 PM

The super cell thunderstorms that produced large hail, strong wind gusts around 65 mph, and a few wall clouds (possibly a tornado) over eastern Pennsylvania and the immediate Philadelphia metro has consolidated into a strong line of thunderstorms that will move through all of New Jersey and eventually all of the New York City.

The majority of the thunderstorms associated with this line will remain below severe levels, however the thunderstorms that do reach severe levels will be capable of strong wind gusts up to 65 mph, very heavy downpours, frequent lightning, and large hail.  I think the tornado threat is coming to an end however.

1:42 PM

The warm front associated with a strong area of low pressure over the Great Lakes is moving north towards New York City.  Skies have started to clear over central and southern New Jersey with strong clearing skies over Maryland and Delaware.  

Expect clouds over much of eastern Pennsylvania, New Jersey, and the immediate New York City metro to break up, which will allow for the low level boundary layer to warm rapidly  into the mid to possibly upper 60′s.  This will significantly destabilize the atmosphere and produce an environment favorable for severe weather.  

 A line of showers and thunderstorms over south-central Pennsylvania will continue to intensify  this afternoon.  The additional destabilization of the atmosphere combined with a strong low level jet around 50 KT over southern New Jersey will lead to the development of thunderstorms capable of wind gusts up to 65 mph, large hail, and an isolated tornado.  

I will keep track of these storms through the afternoon.  Should the storm reach severe levels, I will update on the status of these storms while they impact the forecast area.  An observations post will be added at the appropriate time.

7:31 PM

A warm front over the Southeast is moving north towards the southern Mid Atlantic coast.  A weak disturbance along the warm front is racing towards the DELMARVA Peninsula with an area of showers.  The lifting associated with this disturbance is weakening, however along with overcast skies a few showers can be expected tonight into tomorrow morning as the disturbance moves off the coast.

Model guidance is also consolidating around the idea of an occluded front forming over the forecast area Saturday night through Sunday morning.  When an occluded front forms, the warmest segment of the atmosphere is lifted above the two cooler layers.  In this case; the warm, moist contenential tropical air mass over the Southeast will be elevated over the cool Marine air mass that has been over the forecast area and the cool, Polar air mass over the Plains and eventually the Great Lakes.  The combination of these air masses produces an environment where steady, heavy rain can develop along with elevated thunderstorms.  There is a growing risk for embedded severe thunderstorms will be a threat over southern New Jersey on Sunday as this is where the atmosphere is likely to be the most unstable.  

If severe weather becomes likely, much like the winter, the website will go into “storm mode” with constant updates and a post for observations.

9:12 PM

The winter pattern is still lingering in the northern branch of the Polar jet stream as we continue to see the continuation of a back and forth game between the North Atlantic Oscillation and the Eastern Pacific Oscillation.  As the negative NAO begins to collapse once again early this coming week, the negative EPO (which had all but disappeared through the end of February and into early March) will make another return.  The latest stratospheric anomaly positions and upper tropospheric wind currents strongly suggest a return to the negative EPO pattern seen through much of the winter.  

While the southern branch of the jet stream will continue to strengthen going forward through March and the overall Polar jet stream begins to reposition northward, the return of the negative EPO pattern will keep a trough over eastern Canada and the northern half of the eastern United States.  

So what does this mean for March?  Well, while the winter storms are all but done for the forecast area given the moderating Polar air mass and the shifting of the Polar jet stream northward, the continuation of colder than normal air masses over the forecast area will remain.  This means that while moderation will slowly take over, especially in the middle of this coming week, the support for a trough in the East will keep the Southeast ridge positioned off the coast and send a parade of cold fronts through the forecast area.  

This pattern also will produce generally dry conditions over the East and limit the potential for strong low pressure systems to bring significant moisture into the forecast area.

6:57 AM

The early spring like weather is going to be coming to an end in the next 48 hours, so I would enjoy the warm temperatures as much as possible today before winter returns.  

The cold front is still well west of the forecast area, which means the region is in the warm sector of this large and destructive low pressure system.  Brief side note, one of the tornadoes that hit Oklahoma City was on the same street that I used to live on.  I hope the people there will be okay as I can say from my own experience that being in a tornado can be very scary.  The forecast area will not have to deal with tornadoes from this cold front, thankfully.  The majority of the PVA associated with the low pressure system will move towards southeastern Canada over the next 12 to 24 hours.  Ahead of the cold front, scattered showers will develop through this afternoon.  A few isolated thunderstorms may develop, especially over eastern Pennsylvania where the lifting will be slightly more concentrated.  

By tonight, the strong cold front will begin to move through the region.  For the most part, a steady heavy rain and gusty conditions can be expected.  A few embedded thunderstorms may reach severe levels with wind gusts up to 50 mph possible in the strongest thunderstorms.  Overall though, I don’t expect this to be a wide spread severe event given the best lifting at the upper and mid levels will be well north and west of the forecast area.  

As for the temperatures over the next 24 to 48 hours, very warm conditions can be expected for the most part.  If the sun was to break out, there would be support for temperatures rising into the mid 60′s with 850 temperatures ranging in the 8 to 10°C range.  However, with the overcast skies, most locations will be in the upper 50′s.  However, I can make a case for lower 60′s over parts of southern New Jersey so will keep the range of the previous forecast intact.  For Thursday, the cold front will be moving through in the early morning hours.  This means that temperatures will remain in the 50′s this evening into the morning hours of Thursday.  As a result, the high temperatures on Thursday will be in the morning hours.  As cold air advection (CAA) enters the forecast area, temperatures will slowly fall in the afternoon into the 40′s and 30′s.  

Strong high pressure will build into the region by Thursday night and Friday morning.  Clear skies and colder conditions will return to the forecast area with temperatures averaging near to below normal.  Friday is going to feel a lot colder than the actual temperatures because of the shock of going from the 50′s to the 30′s and 40′s in a short period of time.