Severe Weather Coordination Message #1 – Thursday July 26th, 2012 Major/Significant Severe Weather Outbreak Potential
Hello to all..
..Potentially significant severe weather outbreak for much of Southern New England Thursday Afternoon and Evening..
..The Storm Prediction Center (SPC) has placed portions of Western New England in a Moderate Risk for Severe Weather with the remainder of Southern New England in a high-end slight risk for severe weather. Damaging Winds, Large Hail and urban and poor drainage flooding are the primary threats. Isolated tornadoes cannot be ruled out particularly in the moderate risk area. NWS Taunton is in agreement with this threat..
..The severe weather threat timeframe is after 3 PM for western areas and after 5 PM for eastern areas. It is noted that activity could last well into the evening and overnight hours..
..SKYWARN Activation with Ops at NWS Taunton will commence at 2 PM ET Thursday through late evening Thursday/early morning Friday..
..ARES/RACES Groups should closely monitor the progress of this situation and seek advice from their local leadership..
The Storm Prediction Center (SPC) has placed portions of Western New England in a Moderate Risk for Severe Weather with the remainder of Southern New England in a high-end slight risk for severe weather. Damaging Winds, Large Hail and urban and poor drainage flooding are the primary threats. Isolated tornadoes cannot be ruled out particularly in the moderate risk area. NWS Taunton is in agreement with this threat.
Reviewing computer models, radar and satellite data, overnight tonight into Thursday Morning, a warm front is draped across the region and will migrate northeastward during this timeframe. A Mesoscale Convective System (MCS) is expected to track somewhere across this warm frontal boundary during this period. This could come over Southern New England or possibly track to our north. Initially, there will be cloud debris with this system that could last until midday Thursday. This system is not expected to be severe and will likely weaken as it approaches the region.
All computer weather models are insistent on clearing out the region and that will allow for rapid heating and destabilization. Shear profiles will be very strong given the proximity of the warm front over the region and will allow for turning in the atmosphere. As this occurs, this will allow for scattered to numerous strong to severe thunderstorms to develop. The threat timeframe will be after 3 PM in western parts of the area and after 5 PM in eastern parts of the area. Activity will last well into the evening hours Thursday into early Friday Morning. The potential is there for a significant/major severe weather outbreak for much of the region based on the location of the Moderate risk and high-end slight risk areas.
As always with severe weather scenarios, there are risks/caveats to the forecast for a significant outbreak particularly in New England and remember that isolated to scattered areas of significant issues typically occur in these scenarios meaning not all areas get hit. From a risks/caveats to the forecast point of view, there are two main caveats:
1.) Cloud debris doesn’t thin out as models predict holding back instability parameters.
2.) The position of the warm front doesn’t migrate as far northeast as current model trends indicate keeping portions of the region cooler.
At this time, there are fairly strong indicators based on the current computer weather models that a significant severe weather outbreak is possible leading to the rare issuance of a ‘moderate risk’ severe weather area for Western New England and a ‘high end slight risk’ severe weather area for the remainder of Southern New England approximately 24 hours away from the potential situation.
SKYWARN Activation with Ops at NWS Taunton will commence at 2 PM ET Thursday through late evening Thursday/early morning Friday. ARES/RACES Groups should closely monitor the progress of this situation and seek advice from their local leadership. The next coordination message will be issued by 9 AM Thursday Morning. Below is the NWS Taunton Hazardous Weather Outlook and SPC Day-2 Convective Outlook:
NWS Taunton Hazardous Weather Outlook:
http://kamala.cod.edu/ma/latest.flus41.KBOX.html
SPC Day-2 Convective Outlook:
http://kamala.cod.edu/offs/KWNS/1207231732.acus02.html
Respectfully Submitted,
Robert Macedo (KD1CY)
ARES SKYWARN Coordinator
Eastern Massachusetts ARES Section Emergency Coordinator
Home Phone #: (508) 994-1875 (After 6 PM)
Home/Data #: (508) 997-4503 (After 6 PM)
Work Phone #: 508-346-2929 (8 AM-5 PM)
Email Address: rmacedo@rcn.com
http://ares.ema.arrl.org
http://beta.wx1box.org