Posts

Tom Stavola

Summer Outlook 2013

/0 Comments/by

Below, you will find our 2013 Summer Outlook. We’ve laid out the details and broken down the expected temperatures and precipitation, as well as factors and reasoning involved in the outlook. We encourage your comments, thoughts and feedback!

Factors/Expectations:

1) Neutral ENSO conditions should persist through the upcoming summer with sea surface temperature anomalies (SSTA) not far from normal in the tropical Pacific.

2) The negative Pacific Decadal Oscillation (PDO), or cold eastern Pacific, that we saw through winter has weakened somewhat, but will continue to be slightly negative/cold this summer season.

3) The Atlantic Multidecadal Oscillation (AMO) continues to run slightly positive/warm, with a SSTA profile of warmth near the East Coast, cold in the central Atlantic, and warm in the deep tropics.

4) The strong blocking pattern of negative North Atlantic Oscillation (NAO) and negative Arctic Oscillation (AO) that yielded a very cold late winter/early winter has since dissipated. Both indices have been predominately neutral to slightly positive over the past several weeks, and the historical tendency is for this to continue into the ensuing summer. There may be a one month period of –NAO/AO, but the overall signaling should be near neutral or slightly positive in terms of the NAO/AO blocking indicators.

5) The closest, most similar analog to the present conditions in terms of PDO, NAO, AO, PNA, ENSO, and other factors appears to be 2001. Note that analogs are utilized as tools to identify patterns and obtain clues from the past that may enable us to more accurately forecast the future. No one year is identical in pattern to another year.

6) Palmer Drought Index and Standardized Precipitation Index for the month of May have shown to be excellent foretellers of the June-July-August (JJA) temperature anomalies across the Continental United States (CONUS). The correlation is a strong one, when examining the past 20 years. Areas of drought/dry persistence in May tend to be the breeding grounds for heat in the summer and strong ridging. Likewise, areas of wetness / high soil moisture in the late meteorological spring tend to indicate an ensuing summer of coolness or at least less frequent heat spells.

7) Patterns of strong blocking in the late spring often foretell summers of strong USA heat while patterns devoid of blocking in late spring tend to yield summers of weaker USA heat.

Read more

John Homenuk

Clouds, showers expected through Tuesday PM

/0 Comments/by
NAM model showing heavy rain impacting the area Tuesday afternoon and evening along a cold front. Clearing is expected behind the front by Wednesday.

NAM model showing heavy rain impacting the area Tuesday afternoon and evening along a cold front. Clearing is expected behind the front by Wednesday.

Ahead of an approaching cold front, clouds and showers are expected to become more numerous throughout the area beginning late this Monday evening. Despite warm temperatures aloft (thanks to a mid and upper level ridge), southeast winds at the surface will keep the air cooler and damp through most of the area ahead of the approaching front. Low clouds and drizzle are a possibility throughout most of Tuesday. However, there is an isolated chance of some peaks of sun by Tuesday afternoon as winds turn more southerly. This usually occurs directly ahead of the front, so it will be short lived. A period of steady rain is likely Tuesday afternoon and evening as the front crosses the area from west to east, beginning in Western New Jersey and eventually making its way through NYC and Long Island.

Behind the front, winds will quickly shift from southeast to northwest with temperatures dropping accordingly. The new colder airmass will settle into the area by Wednesday with highs in the upper 40’s, but cold northwest winds keeping it chilly. The blustery west-northwest winds are expected to stick around through the end of the week — so enjoy the warm air while it’s still here!

Tonight: Mostly cloudy with a slight chance of drizzle. Lows in the lower to mid 40’s throughout most of the area, a bit warmer near the coast. Southeast winds 10 to 15 miles per hour.

Tuesday: Mostly cloudy with rain likely. The rain may be heavy at times. Highs in the mid to upper 50’s. Southeast winds turning southerly around 20 miles per hour.

Tuesday Night: Mostly cloudy with rain likely early, then clearing. Lows in the upper 30’s to lower 40’s.  Southerly winds turning west-northwest around 20 miles per hour.

Wednesday: Mostly sunny with a slight chance of showers. Cooler, with a high in the upper 40’s. Blustery northwest winds around 20 miles per hour.

John Homenuk

Beautiful weekend weather will continue

/3 Comments/by

May began as April ended, with a streak of slightly below-normal temperatures and plenty of showers around the area. To be fair, it hasn’t been a total

NAM Model showing high temperatures in the 80's on Sunday

washout. Still, the change in weather from what we were experiencing about a month ago today has been rather dramatic. Temperature departures would run over 10 degrees above normal by the middle of April, and through may we have averaged near normal with some areas slightly below normal. The good news, however, is that the showery weather is on the way out. The cold front which was near the area Tuesday and Wednesday has been swept offshore and to our east — and after a cool and windy day Thursday, temperatures rebounded the first half of the weekend.

Temperatures in the middle to upper 70’s on Saturday will give way to more 80 degree temperatures away from the shore on Sunday. Temperatures could rise into the upper 70’s even near the shore during the early hours of Sunday afternoon. However, a seabreeze by afternoon looks to lower temperatures by early evening near the beaches and the local waters. Inland, temperatures in the 80’s could continue to sunset.  The pattern won’t stay overly warm, though, as a trough is expected to work back into the area by next week. Although it won’t be too strong (rather broad, actually) some showers and a bit of unsettled weather is possible during the week once again. Steady rain may work into the area by late Tuesday into Wednesday. We’ll keep an eye on it!

Remember to keep an eye on our 5 day forecast graphic, hazards table, and forecast briefing by using the navigation table to the left. You can also check out a quick glance at the forecast by glancing to the right at our forecast at a glance widget.