A cold front that extends from Northern New England back through the Great Lakes and into the Midwest will finally get moving today.  The result is widespread showers and thunderstorms over areas that have already received a lot of rain in the last month.  For this reason various National Weather Service Offices have issued Flash Flood Watches

(Note- tropical watch below)

National Weather Service Flash Flood Watches 07/08/13

National Weather Service Flash Flood Watches 07/08/13

Here is the current surface chart

WPC Surface Analysis 2 am

WPC Surface Analysis 2 am

The high pressure that dominated the weather across the Northeast last week has shifted south.  This is finally allowing low pressure from the Midwest to make its way east.  While it is not forecast to be as warm today in the Northeast it already is a warm Monday morning.   The cold spot in the Northeast is far Northern Maine

4 am 2 m temps (image weatherbell)

4 am 2 m temps (image weatherbell)

The air remains very tropical hence the reason for flash flood watches.  Any values above 1.5 make an area prone to flash flooding and that is what we see from Maryland to Maine.

09z SPC Mesoanalysis Precipitable Water

09z SPC Mesoanalysis Precipitable Water

Here is the Northeast Regional Radar.  There is action in Central/Northern New England, just off the South New England Coast, as well as Virginia and Maryland.

NWS Northeast Regional Radar 558 am

NWS Northeast Regional Radar 558 am

Short Term Forecast

Temperatures by 10 am will be in the low 80’s for Eastern regions of the northeast.  Central and Northern Maine and Upstate NY, Western PA will remain in the low 70’s

06z NAM Hires 2 m temps 10 am (image weatherbell)

06z NAM Hires 2 m temps 10 am (image weatherbell)

We can expect precipitation to begin from West to East and that is part of the reason temperatures will be down.  The front will sag towards Southern NH and VT while low pressure rides along the boundary out of the Great Lakes

WPC Surface Forecast 2 PM

WPC Surface Forecast 2 PM

A trough of low pressure will provide a focus for thunderstorm development this afternoon.  The SPC does not think the threat will be severe in nature but isolated severe weather is possible, especially NY/PA/VT and Western MA/CT.

SPC Day 1 Thunderstorm Outlook

SPC Day 1 Thunderstorm Outlook

Temperatures this afternoon will get warm.  Norwood, MA may extend its 90 degree streak to 6 days.  Boston may touch 90 but we feel temperatures stay in the upper 80’s.  A strong coastal front looks to develop this afternoon in SE New England.  New Jersey, New York City, Baltimore, DC will all be in the low 90’s with dew points in the low 70’s

06z NAM Hires 2 m temps 3 PM (image weatherbell)

06z NAM Hires 2 m temps 3 PM (image weatherbell)

In general 0.1-0.25 inches of rain are expected with higher amounts in Northern New England.  Any areas that are impacted by thunderstorms will also see locally higher amounts

WPC Day 1 Precipitation Outlook

WPC Day 1 Precipitation Outlook

See Chris’s post for the long range Northeastern US forecast.

Tropical Watch

As we indicated yesterday Invest 95L developed into the 3rd named system of the 2013 North Atlantic Hurricane Season

NHC Official Advisory and Forecast Track Tropical Storm Chantal

NHC Official Advisory and Forecast Track Tropical Storm Chantal

The National Hurricane Center (NHC) believes Chantal will stay weak as she moves around the large high pressure area in the Southwestern Atlantic.  It still appears that the biggest threat to anyone will be heavy flooding rains.  More tropics later on tonight, have a good day.

-Zack Green

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