Wednesday, June 19, 2013

High Pressure Takes Control

After several months worth of rain in just a few weeks high pressure from the Great Lakes will build into the Northeast and keep conditions dry for an extended period of time.  We will still be vulnerable to afternoon thunderstorms by the time the weekend rolls around but the next 48-72 hours are dry.

Observations/Short Term Forecast
Two cold fronts, one from Monday and the other from yesterday are just offshore.  A Nor'Easter developed along one of the fronts yesterday and brought heavy rain to the Mid Atlantic, particularly New Jersey
WPC Surface Analysis 2 am
The rainfall from the fronts is now far enough offshore that it not being picked up on radar.  However there is a Small Craft Advisory for the Cape.  Anytime a storm departs there is a tight pressure gradient on the back side as a high builds to the west, a low races to the east.  This will create some choppy seas; be careful if venturing into the ocean today.  Temperatures this morning are in the upper 50's along the South Coast of CT. RI and Eastern MA.  The rest, save for the Berkshires are in the low to mid 50's
2 m temps 4 am (image weatherbell)
At the 500 mb level the set up looks like this
06z NAM 500 mb geo height 8 am Wed (image weatherbell)
The ridge over the central US will try to work into the east as the cut off along the Pacific NW coast moves to the Northeast.  The result today is a surface chart with a high building from the Great Lakes with a dry northwest wind.
WPC Surface forecast 8 PM
The winds will relax as the low moves away this afternoon.  None the less I am expecting temperatures to generally be in the low to mid 70's with party cloudy skies.
06z NAM hires 2 m temps 3 PM (image weatherbell)
Clear skies tonight will allow for temperatures to drop into the upper 40's in the cold spots (Berkshires, NW CT, NW Worcester County) and the low 50's for everyone else.  Thursday is almost a carbon copy of today except that is will be slightly warmer with more sun.
06z NAM hires 2m temps 2 pm Thur (image weatherbell)
Our high pressure will begin to slide offshore on Thursday afternoon and evening
WPC surface forecast 8 PM Thursday
This will flip the wind over to the Southwest on Friday and that will re introduce the humid air.  The high in the Mid Atlantic will take over as the dominant driver
WPC Surface Forecast Friday 8 am
Notice how the 500 mb will evolve from today through Friday evening
06z NAM 500 mb geo height Friday 8 PM
The subtropical ridge has finally popped.  Temperatures Friday will easily be in the low to mid 80's
06z NAM hires 2 m temps Fri 2 pm (image weatherbell)
Friday night is dry and mild.  Here is the 3 day WPC precipitation forecast.  This is certainly nice to see for a change
WPC 3 day precipitation outlook
This is valid through Saturday 8 am.  Saturday afternoon we will need to watch for some afternoon thunderstorms.  A stalled boundary will set up in central New England.  Along this boundary storms will fire.  The EURO keeps the boundary in North Central New England but I cannot rule out a isolated shower/storm in Southern New England.  
00z EURO 2 m max T Sat PM (image weatherbell)
Here is the precipitation
00z EURO 6 hr precip Sat PM (image weatherbell)
At the very least enjoy the next several days.  

Tropics Watch
Tropical Depression 2 has formed in the Bay of Campeche (well formed near Belize but is currently in BOC).  
GOES_East Infrared Rainbow Satellite (NOAA) 545 am
The storm is expected to develop into Tropical Storm Barry before moving into Mexico with heavy flooding rains.
Official NHC track, watches & warnings
Have a good Wednesday

















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