Severe Weather Coordination Message #3 – Monday 7/14/14-Wednesday 7/16/14 – Severe Weather Potential

July 14, 2014 Rob Macedo Leave a comment

Hello to all..

..Isolated to Scattered strong to severe thunderstorms remain likely across much of Southern New England on Monday. The Storm Prediction Center (SPC) has continued a slight risk of severe weather for Connecticut, Rhode Island and Western and Central Massachusetts with 5% severe weather probabilities for the rest of Southern New England except for Cape Cod and the Islands for Monday. Strong to Damaging winds, hail and heavy rainfall with urban and poor drainage flooding to flash flooding are the main threats though an isolated weak tornado is also possible..
..A Flash Flood Watch Has Been Issued from 2 PM This Afternoon through late Tuesday Night for Northern Connecticut and Hampden, Hampshire, Franklin, Worcester and Northern Middlesex Counties of Massachusetts for the potential of back building thunderstorms and heavy rainfall. This Flash Flood Watch could be extended eastward as we get into Tuesday and Wednesday..
..Additional potential exists for Isolated to Scattered Strong to Severe Thunderstorms on Tuesday as SPC has much of Southern New England in a 5% risk for severe weather. This will be contingent on cloud cover and the prior day’s convective activity. The threat could then continue for Eastern New England into Wednesday..
..SKYWARN Activation with Ops at NWS Taunton will commence by 400 PM and lasting through late Evening. SKYWARN Activation with Ops at NWS Taunton is also likely on Tuesday and possible on Wednesday..

Last night saw severe weather stay to the west of the NWS Taunton coverage area over in Litchfield County Connecticut and Eastern New York but thunderstorms with heavy rainfall occurred in some parts of the NWS Taunton coverage area. Southwick, MA received 2.1″ of rain for the event with 1.3″ of rain coming in just a 70 minute period.

As we move into today, a slow moving cold front will be approaching Eastern New York and New England. At 900 AM, satellite imagery showed considerable breaks in the clouds over Southern New England. There will be warm and humid conditions over the area that will create a level of instability and with sufficiently strong wind shear profiles. As the slow moving cold front approaches the region, that will set the stage for isolated to scattered strong to severe thunderstorms over the area. The timing is a bit uncertain though it now appears that thunderstorm development is now expected to hold off until after 400 PM though this will be monitored closely. The Storm Prediction Center (SPC) has continued a Slight Risk of severe Weather for Connecticut, Rhode Island and Western and Central Massachusetts with 5% severe weather probabilities for the rest of Southern New England except for Cape Cod and the Islands for Monday. Strong to Damaging winds, hail and heavy rainfall with urban and poor drainage flooding to flash flooding are the main threats though an isolated weak tornado is also possible.

Any thunderstorms today across portions of Western Massachusetts and Northern Connecticut will have the potential to produce heavy rainfall and if they back build over the same area, they could produce flash flooding. This could occur from Monday Afternoon through late Tuesday Night. A Flash Flood Watch has been issued from 2 PM this afternoon through late Tuesday Night for Northern Connecticut and Hampden, Hampshire, Franklin, Worcester and Northern Middlesex Counties of Massachusetts for the potential of back building thunderstorms and heavy rainfall. This Flash Flood Watch could be extended eastward as we get into Tuesday and Wednesday.

For Tuesday, SPC continues a 5% risk of severe weather across much of Southern New England and any thunderstorms will have the potential for heavy rainfall ad flooding. Tuesday has the potential to be a repeat of Monday with the severe weather threat potentially evolving into a flash flood threat as we get into Tuesday Evening into Wednesday Morning. This will be contingent on cloud cover and the prior day’s convection. Further details on the threat for Tuesday will be defined in future severe weather coordination messages. There may also be a threat for isolated to scattered strong to severe thunderstorms into Wednesday across parts of Eastern New England depending on the timing and speed of the slow moving cold front as well. This will also be discussed in future coordination messages.

SKYWARN Activation with Ops at NWS Taunton will commence by 400 PM and lasting through late Evening. SKYWARN Activation with Ops at NWS Taunton is also likely on Tuesday and possible on Wednesday. This will be the last coordination message issued on Monday’s severe weather potential. The next coordination message will be issued by 1130 PM Monday Evening. Below is the NWS Taunton Hazardous Weather Outlook, NWS Taunton Facebook Graphic and SPC’s Day-1 and Day-2 Convective Outlooks:

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

NWS Taunton Facebook Graphic:
http://beta.wx1box.org/local/2014.07.14_AM_Fcst.png

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

SPC Day-2 Convective Outlook:
http://www.spc.noaa.gov/products/outlook/day2otlk.html