Severe Weather/Flash Flood Coordination Message #1 – Wednesday August 13th, 2014 Severe Weather/Flash Flood Potential
Hello to all..
..Heavy Rainfall with the potential of Isolated to Scattered Strong to Severe Thunderstorms very late Tuesday Night and Wednesday across much of Southern New England. Urban and poor drainage flooding to flash flooding of these areas and possibly small streams is the main threat but there is a secondary threat for strong to damaging winds and possibly even an isolated brief tornado as well in any severe thunderstorm. The Storm Prediction Center (SPC) has placed much of Southern New England in a ‘see text’ 5% severe weather probability category for Wednesday..
..A Flash Flood Watch is now in effect from late Tuesday Night Through Wednesday Afternoon for Cheshire County New Hampshire, Northern Connecticut, Northwest Providence County Rhode Island and Franklin, Hampshire, Hampden, and Worcester Counties of Massachusetts. This Flash Flood Watch could be expanded further east in later forecasts..
..Minor Coastal Flooding is possible at the time of high tide mid-morning Wednesday in South Coastal Massachusetts and Rhode Island and then extending into portions of East Coastal Massachusetts during the Wednesday Afternoon High Tide..
..SKYWARN Activation with Ops at NWS Taunton are likely from Wednesday Morning through Wednesday Evening..
An unusually strong summer storm system will affect much of Southern New England Wednesday. The main impact will be from heavy rainfall causing urban and poor drainage flooding to flash flooding across portions of Southern New England with some potential for small stream flooding as well. A Flash Flood Watch is now in effect from late Tuesday Night Through Wednesday Afternoon for Cheshire County New Hampshire, Northern Connecticut, Northwest Providence County Rhode Island and Franklin, Hampshire, Hampden, and Worcester Counties of Massachusetts. This Flash Flood Watch could be expanded further east in later forecasts. Rainfall amounts of 1-3″ with isolated higher amounts of up to 4-5″ possible in the region.
There is a secondary threat for isolated to scattered strong to severe thunderstorms with the potential for strong to damaging winds and possibly even a brief isolated tornado. Wind shear profiles and turning in the atmosphere will be quite favorable for this to occur, however, the heavy rainfall, expected cloud cover in the warm sector and the marine influence could mitigate this threat. Given that August features warmer sea surface temperatures and the fact that jet dynamics will be favorable, the key to any severe weather potential during Wednesday will be any instability or destabilization that can occur during the day either through any breaks in the cloudiness or from the very high moisture laden air that will be over the region and any embedded thunderstorms that can tap into the dynamics. The main threat of this storm system is flash flooding but similar to 2 weeks ago, isolated to scattered strong to severe thunderstorms capable of strong to damaging winds and perhaps a brief isolated tornado cannot be ruled out. The Storm Prediction Center (SPC) has placed much of Southern New England in a ‘see text’ 5% severe weather probability category for Wednesday.
A third threat is for minor coastal flooding at the time of high tide mid-morning Wednesday in South Coastal Massachusetts and Rhode Island and then extending into portions of East Coastal Massachusetts during the Wednesday Afternoon high tide. The ‘supermoon’ high tide cycle coupled with southeast onshore winds may allow for more vulnerable south coastal locations to experience minor coastal flooding. This could also exacerbate heavy rainfall flooding issues in areas that can also be affected by tidal influences.
SKYWARN Activation with Ops at NWS Taunton are likely Wednesday Morning through Wednesday Evening. Below is the NWS Taunton Flash Flood Watch Statement, Hazardous Weather Outlook and SPC Day-3 Convective Outlook:
NWS Taunton Flash Flood Watch Statement:
http://kamala.cod.edu/ma/latest.wgus61.KBOX.html
NWS Taunton Hazardous Weather Outlook:
http://kamala.cod.edu/ma/latest.flus41.KBOX.html
SPC Day-3 Convective Outlook:
http://www.spc.noaa.gov/products/outlook/day3otlk.html
Respectfully Submitted,
Robert Macedo (KD1CY)
ARES SKYWARN Coordinator
Eastern Massachusetts ARES Assistant 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
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