Severe Weather and Heat Coordination Message #3 – Saturday 7/20/13 Severe Weather & Heat Potential

July 20, 2013 Rob Macedo Leave a comment

Hello to all..

..One more day of intense heat and humidity with Heat Advisories posted for much of the region today..
..The heat will come to an end today as the potential exists for at least isolated to scattered strong to severe thunderstorms across much of the region today with damaging winds, large hail and urban/poor drainage flooding as the primary threats. A more widespread severe thunderstorm event remains possible but some uncertainty now in the most favorable location and the coverage of strong to severe thunderstorms today in Southern New England as remnant storm complexes bring some cloud cover and possibly showers to the region this morning as well as the timing of the cold front..
..The Storm Prediction Center (SPC) maintains a Slight Risk for Severe Weather Across Much of Southern New England..
..SKYWARN Activation with Ops at NWS Taunton will commence by 1 PM today lasting through evening and we will monitor for an earlier start time if needed..

There will be one more day of heat today as the heat wave enters its last day. Today will not be as hot as Friday but will still likely have heat indices near or over 100 degrees with temperatures around or over 90 degrees. Heat Advisories have been posted for much of the region. See the following link for details on the heat:

http://kamala.cod.edu/ma/latest.wwus71.KBOX.html

As has been advertised for several days now, the heat will come to an end today as a cold front will make its way through the region bringing an end to the intense heat and humidity. With the cold front, will come the threat for isolated to scattered strong to severe thunderstorms across much of the region today with damaging winds, large hail and urban/poor drainage flooding as the primary threats. There is a bit of uncertainty as to the primary locations and the extent of the strong to severe thunderstorm threat based on what occurred last night for strong to severe thunderstorms in New York and Northern New England. This has setup the following uncertainties:

1.) Cloud cover from remnant thunderstorm complexes moving in from New York State. Satellite imagery shows cloud cover moving in over portions of Western New England and Doppler radar is showing a weakening short line of thunderstorms in Eastern New York and scattered showers moving into Connecticut followed by a break in the cloud cover then thicker clouds associated with the cold front further west into Central New York State. It is unclear how much reduction of heating this will make for the region or whether activity may intensify as it reaches Eastern New England where more heating is occurring prior to the activity moving into the area. Also, latest Satellite trends have shown some thinning of the clouds over the past hour.

2.) The timing of the cold front and any air mass recovery needed based on cloud cover that moves through the region this morning.

Despite the uncertainties an isolated to scattered strong to severe thunderstorm threat still exists for today possibly occurring as early as late morning to midday and lasting through this evening and more widespread activity cannot be ruled out if enough heating occurs and depending on the timing and forcing of the cold front. SKYWARN Activation with Ops at NWS Taunton will commence by 1 PM today lasting through evening. An earlier start is possible if current shower and thunderstorm activity were to intensify as it moves into the region. This will likely be the last coordination message on Saturday’s Severe Weather Potential and the heat wave. Below is the NWS Taunton Hazardous Weather Outlook and SPC Day-1 Convective Outlook:

NWS Taunton Hazardous Weather Outlook:
http://kamala.cod.edu/ma/latest.flus41.KBOX.html

SPC Day-1 Convective Outlook:
http://www.spc.noaa.gov/products/outlook/day1otlk.html

Respectfully Submitted,