04/29/10  7:15 AM

The change in the pattern is upon us, and many people are going to really enjoy it!  Me personally, I’m not much of a sun guy.  I burn to easily, which is strange because I’m Italian, and I prefer more active weather obviously.  However, I have a few friends who are going to be jumping for joy with what I’m about to tell you.

The IR satellite picture this morning clearly shows that high pressure, over the Ohio Valley, is clearly in control.  Clear skies are being reported throughout the region and the winds from yesterday and last night are quickly diminishing as the pressure gradient weakens.

This high pressure system will eventually reposition off the North Carolina coast by tomorrow afternoon and remain locked in between the Southeast coast and Bermuda through early next week.  If you want warm, humid temperatures, that exactly where you want that high pressure system!

Temperatures for today will rise into the mid 60′s along the immediate coast to lower 70′s over the Delaware River Valley, but wait it gets better!  For Friday, high temperatures rise into the 70′s for most locations and this weekend will feature highs in the 80′s for most location with the exception of the immediate coast, especially the south shore of Long Island where a southwesterly wind off the Atlantic Ocean will hold temperatures in the lower 70′s.  Of course the big news is that lower 90′s will likely return again for the Delaware River Valley for both Saturday and Sunday.  Get that pool ready!

However, the forecast will be not be completely quiet.  While today through Saturday will basically remain dry with only an isolated thunderstorm possible via heating in the afternoon destabilizing the atmosphere.  The main threat though is a cold front currently over the Rockies.  This cold front will attempt, and fail, to move through the region Monday through Wednesday with the threat of scattered showers and thunderstorms.  A few of these thunderstorms may even reach severe levels, however at this time that appears to be an isolated threat.  Otherwise, the persistent southwesterly flow will continue through next week, keeping high temperatures in the 70′s and 80′s along with dew points in the 50′s and 60′s.  Not bad for May!

For a detailed forecast for the next seven days, go here!

04/22/10  6:56 AM

An area of low pressure that produced showers and a few isolated thunderstorms last evening, is slowly departing into the Atlantic this morning.  Low clouds, fog, and isolated showers still linger over the northern Mid Atlantic, however conditions will rapidly improve over the next several hours as high pressure over central Ontario slowly builds into the northern Mid Atlantic.

Skies will clear by this afternoon with significantly improved conditions for the New York City and Philadelphia metropolitan areas.  With clear skies and a light westerly wind around 5 mph, temperatures will rise into the mid to upper 60′s for most locations.  I would not rule out a few isolated lower 70′s as well for the Delaware River Valley.

Tranquil conditions will continue through Friday and into Saturday afternoon as high pressure slides over the northern Mid Atlantic towards the Atlantic.  Clear skies, low humidity, and temperatures ranging from the mid 60′s to lower 70′s for highs and mid 30′s to upper 40′s for lows can be expected through the period.  However, the tranquil and comfortable conditions will not last long.

The water vapor satellite picture this morning showers a strong upper level low moving through the Rockies and heading towards the Plains.  This upper low will clash with the negative NAO pattern set up over the Canadian Maritimes to make for a rather nasty end of the weekend and start of next week.

A warm front will approach on Saturday night with increasing clouds and rain developing towards mid night.  Rain will continue through the day on Sunday and will be heavy at times.  Due to the strong blocking set up over the Atlantic via the negative NAO pattern, the warm front will stall over the Philadelphia and New York City metropolitan area leading to periods of moderate to heavy rain continuing through Monday.

The upper low will weaken over the Ohio Valley and give way to the stronger upper low over the Canadian Maritimes.  As a result, a surface low will develop and strengthen to the east of the Delaware coast Monday night through Tuesday morning leading to periods of heavy rain as well.

With the persistent easterly winds, there is a threat for some coastal flooding, however I think this threat will be small at this time as the winds are not very impressive with this system.  My main concern for this period will be the potential for heavy rainfall, which will easily exceed an inch and could approach two inches, leading to flash flooding of the rivers and urban locations once again.  I am especially concerned about this threat for northeastern New Jersey once again.

The low pressure system will exit on Tuesday afternoon with clearing conditions through Wednesday.  For a detailed seven day forecast, go here!

04/21/10  7:03 AM

High pressure over the past few days have provided excellent conditions with low humidity, highs in the 60′s, above all else dry conditions.  However, a weak disturbance is on the way that will interrupt the pleasant weather for a short time.

The water vapor satellite this morning is showing two significant disturbances over the United States.  The first disturbance is heading towards the Mid Atlantic coast.  This disturbance is being sheared by the northwesterly flow from the Polar jet stream and as a result is weakening rapidly.  However, the disturbance will still be strong enough to produce a few scattered showers throughout the northern Mid Atlantic this afternoon and evening.

High pressure will quickly become reestablished by tomorrow morning with dry conditions and near normal temperatures Thursday afternoon through Saturday.

The next disturbance is a developing storm that will have a significant impact on the Philadelphia and New York City metropolitan area.  The Pacific disturbance will move through the Rockies and into the Mississippi Valley by this weekend.  As the upper disturbance moves into the Plains and Mississippi Valley on Saturday, an upper low is expected to intensify.  Meanwhile, a back door cold front, a lovely gift from the negative NAO pattern over the Atlantic, will drop south and west through the New York City metropolitan area on Saturday night with increasing clouds.  Now, here is where this pattern gets interesting!

The back door cold front will stall over or just south of the Philadelphia metropolitan area on Sunday morning while impulses or mid level disturbances from the upper low will race along the stationary boundary, that will gradually transition into a warm front, which will produce waves of moderate to potentially heavy rain from Sunday through Monday.  I don’t expect continuous rainfall with these disturbances, but overall Sunday and Monday will not be pleasant outdoors.

The upper low opens up on Monday night and slides towards the coast while a Polar disturbance dives south towards the New England coast, which give birth to a developing coastal low on Monday night into Tuesday with periods of moderate to heavy rain once again.  Overall, not a pleasant start to next week.

For a detailed seven day forecast, go here!

04/13/10  7:20 AM

An active pattern is starting to develop for the northern Mid Atlantic, which is usually expected in the Spring.

The water vapor satellite this morning shows the impacts of a negative NAO pattern as a strong upper low remains over the Canadian Maritimes and eastern Quebec.  This upper low is carving out a well established trough over the Northeast and Mid Atlantic with disturbances over the Ohio Valley and another over the northern Plains.

The first disturbance will move through the Philadelphia and New York City metropolitan area this afternoon and evening with widely scattered showers.  The heaviest precipitation is likely to remain focused over southern Pennsylvania and southern New Jersey as this is where the best mid level and upper level dynamics will be focused.  For the most part, the most significant impact from this disturbance will be the increasing cloud cover and temperatures remaining in the 60′s.

High pressure over the Mississippi Valley will build into the northern Mid Atlantic on Wednesday and Thursday with clear skies and light winds.  Temperatures will rebound into the mid 60′s to mid 70′s for highs on both days as a modified Pacific air mass builds in.

The second disturbance over the northern Plains and Rockies this morning will slide southeast from the eastern Great Lakes towards the northern Mid Atlantic coast on Friday morning.  A warm front will drive north and east on Friday morning with periods of rain over the Philadelphia metropolitan area on Friday morning and rain continuing over much of the New York City metropolitan area in the afternoon through early Saturday morning.  Temperatures will remain cool along the immediate coast with highs in the 50′s and lower 60′s for Connecticut, Long Island, and New York City.  However the rest of the northern Mid Atlantic will be significantly warmer with highs soaring into the mid 60′s to mid 70′s under the influence of strong warm air advection.

A cool regime will take hold for the weekend and the start of early next week with clearing skies and temperatures returning to the upper 50′s to mid 60′s for highs and upper 30′s to upper 40′s for lows.

A detailed seven day forecast can be found here!

7:27 AM

The return of weather that you can enjoy outside has returned and just in time for the weekend!  The gloomy conditions over the past few days have now exited well into the Atlantic as an area of low pressure continues to slowly exit towards Europe.

This morning, high pressure over the Ohio Valley is in control and will remain in control over the next several days.  The air mass with this high pressure system has strong ties to the Pacific, which means the air mass will warm rather easily in the afternoon.  Many locations throughout the New York City and Philadelphia metropolitan areas will warm into the upper 40′s to lower 50′s, ensuring that any snow left on the ground will continue to melt rapidly.

It should be noted that this high pressure system and the associated upper level ridge has actually been the same high pressure system that has sat over much of the West coast and Rockies for the past six weeks.  This is basically the calling card of the end of the active winter pattern for much of the Mid Atlantic and spells a slow but steady return of Spring.

Dry and tranquil conditions will continue on through Thursday morning as high pressure drifts into the Atlantic.  A strong Sub Tropical disturbance will develop over the southern Plains and draw moisture northward from the Gulf of Mexico.  This low pressure system is expected to track towards the Mid Atlantic coast by Friday with wide spread rain throughout the region.  This low pressure system is expected to hang around the Mid Atlantic for a long portion of next weekend with rain, overcast skies, and cool conditions.  Flash flooding may be a significant problem for many locations.