NY NJ PA Weather Forecasts

Evening Podcast:  Tonight, I look at the weak cold front that moved through the Northeast and what to expect over the next several days.  Plus a discussion on Tropical Storm Fay.

Tuesday August 19th, 2008

Good evening everyone!

The latest model guidance that I’m looking at this evening hasn’t changed my mind on what to expect over the next few days.  The disappointing cold front is clearing the forecast area and what will follow over the next several days is high pressure, which will lead to clear skies, cool morning lows, and comfortable afternoon highs.  All in all, a very boring and quiet forecast period for the region.  And based on the latest long range model guidance, the pattern does not appear to break for at least another 5 days after this 7 day stretch!  So that’s 12 straight days of basically quiet weather give or take a few cold fronts here and there.

Now, on to my thoughts for Tropical Storm Fay.  I am starting to get very concerned about the impact of this Tropical Storm for all of Florida and even much of the eastern Gulf Coast.  

First, I have to say, Tropical Storm Fay looks the most organized that I have ever seen from this tropical cyclone.  On the radar and satellite images, we finally have a truly circular structure with convection surrounding the center of the tropical storm.  In fact, even a weak eye wall has formed with subsidence forming an eye from time to time on the IR satellite pictures.  What’s unusual about this is that all of this is happening OVER LAND.  I’ve seen this before in some tropical systems and the reasoning for this development is complicated.  For the sake of time, let’s just acknowledge the fact that Fay has become more structurally sound and closer to hurricane strength than ever before.  

So where will Fay go and how strong can Fay get?  Well let’s ignore the models for a second and think about the upper level synoptic set up and dynamics of the atmosphere.  We have a trough exiting the East coast that will NOT take Fay with the trough.  As a result, we can see Fay slowing the northeastward progress we’ve seen in the last 24 hours.  As the trough leaves, Fay will stall somewhere on or just off the eastern Florida coast around the south side of Melbourne.  By Wednesday evening, a ridge will build over the Mid Atlantic and continue to build south.  Now, the circulation around a high pressure system is clock-wise, and at the position this ridge at 700 MB will be oriented, the steering currents are from east to west.  This developing steering current will force Fay, at this point most likely a category 1 or 2 hurricane, back over the central peninsula of Florida and into the Gulf of Mexico.  Then we enter a heap of trouble, as Fay will have favorable upper level conditions along with plenty of warm sea surface temperatures in the northeastern Gulf of Mexico.  This of course is not good news for anyone from the Panhandle of Florida to Louisiana.  In my opinion, everyone along the eastern Gulf Coast should keep an eye on Fay over the next several days.

The main threat for severe weather will be found over Florida where Tropical Storm Fay is making a second landfall.  When a tropical system moves over land, the additional low level wind shear can lead to the development of tornadoes, which is possible over southern Florida.  Heavy rain and strong wind gusts exceeding 70 mph will be possible in the strong thunderstorm bands.

Meanwhile, a weakening cold front will move through the Northeast with showers and strong thunderstorms.  The upper disturbance associated with the cold front is weakening and focusing much of the lifting to the north and east of the Mid Atlantic and Northeast.  Further, the atmosphere ahead of the cold front is not significantly unstable nor has any indication of enhancement from low level forcing.  Overall, the severe potential for this cold front is slim.

Finally, a weak disturbance will move through the Northwest with showers and thunderstorms.  The cold air aloft will help destabilize the atmosphere and support the potential for large hail.  The strongest thunderstorms will also be capable of wind gusts exceeding 50 mph and producing heavy downpours.

The local forecast discussion is updated!

This morning, the cold front over the eastern Great Lakes is on the march and will move through the entire forecast area by the early evening.  The showers and thunderstorms with this cold front are not expected to be impressive, but some rain never hurts, right?  From there, high pressure 24/7.  You want it, we got it!  Unlimited supply of clear skies, comfortable temperatures, and not much for me to talk about.  Except of course Tropical Storm Fay, which according to models may be floating around the Southeast and Gulf Coast for some time in one form or another.

Thoughts covered in the technical forecast discussion:

1. Cold front today, high pressure tomorrow!

2.  High pressure sets up beach house in New Jersey.

3. Getting cool out there, huh?

4.  Fay, where are you going?