Tag Archive for 'cold air'
January 7th, 2009 by Steven DiMartino
7:51 AM
Taking a look at the pattern via surface maps, the potential and interest in the pattern through this weekend into next week would best be described as boring, especially the GFS. However, if one was to look at 500 MB, they would come away with a totally different perspective on this pattern that is [...]
January 7th, 2009 by Steven DiMartino
6:20 AM
I think I’ll start with the good news. The east wind has done its job as expected and has warmed the entire coastal plain above freezing including the major cities and surrounding suburbs. Heavy rain can be expected through the day as the best dynamics continue to be present over the forecast area. This [...]
January 6th, 2009 by Steven DiMartino
9:40 PM
There are some indications that I’ve seen in the past hour that has me a bit worried about significant ice for central, western, and northern New Jersey and much of eastern Pennsylvania.
At this point, most model guidance had the low level cold air pushed out of central and southern New Jersey and warm air [...]
January 6th, 2009 by Steven DiMartino
7:48 PM
Right now, if you are along the immediate coast, your snow and ice worries are all but over. The strengthening warm air advection off the Atlantic supported by the developing 850 MB low over the Tennessee and Ohio Valley has warmed the majority of the atmosphere above freezing, thus producing all rain for coastal [...]
January 6th, 2009 by Steven DiMartino
7:27 AM
The first observation I noticed throughout the forecast area was how dry the air was. This is a big deal everyone for one simple reason. Evaporational cooling.
The precipitation seen over Delaware and Maryland will slowly push north today, as high pressure gives way over the next 8 to 12 hours. Clouds will continue to [...]
January 5th, 2009 by Steven DiMartino
7:40 PM
At this time, my thoughts for the storm on Tuesday night through Wednesday have not changed. However, I wanted to go over again how I think everything will evolving from Tuesday afternoon through Wednesday afternoon.
Tuesday Morning: On Tuesday morning, clouds will increase throughout the forecast area. High pressure will be giving way to the [...]
January 4th, 2009 by Steven DiMartino
7:30 PM
Tonight I want to focus on the increasing threat for heavy rain and significant icing for the forecast area.
As seen on the map above, the majority of the forecast area will have mostly rain to contend with by the Wednesday morning rush hour. A total of 1 to 2 inches of heavy rain will [...]
January 3rd, 2009 by Steven DiMartino
8:00 AM
I want to deal with a few issues before going into the forecast.
First, the strong NAO is not a pattern that supports significant winter storms usually. It is the change from one NAO state to another that tends to support large winter storms. The best case scenario is a weak, negative NAO or a [...]
December 31st, 2008 by Steven DiMartino
8:07 AM
There are some interesting themes that are coming from the medium range guidance over the past few runs that need to be addressed as we move into the first full week of January, 2009.
The first theme that the model generally agree on is that the block over Greenland will significantly intensify to build down [...]
December 29th, 2008 by Steven DiMartino
8:59 PM
If you put your ear to the ground, you could hear the fall of a million snow lovers faint to the ground after seeing the 12Z GFS, which basically if taken verbatum would produce a significant snowfall for most of the forecast area, save southern New Jersey (even that location would still get measureable [...]