Severe Weather Coordination Message #2 – Wednesday 8/22/18 Severe Weather Potential

Hello to all…

..Isolated to Scattered Strong to Severe Thunderstorms are possible on Wednesday in two possible timeframes. The first timeframe is in the morning hours between 4 and 10 AM and the second timeframe is in the mid-afternoon to early evening. Strong to damaging winds, hail, frequent lightning and heavy rainfall leading to urban and poor drainage flooding are the main threats but an isolated tornado particularly during the morning hours is a secondary threat. The Storm Prediction Center (SPC) has placed much of Southern New England in a marginal risk for severe weather..

..SKYWARN Activation is likely Wednesday. Self-Activation will be utilized in the morning and Ops at NWS Boston/Norton could be utilized for the Wednesday Afternoon/Evening timeframe..

There is the potential for two rounds of potential severe weather on Wednesday, one with the warm front Wednesday Morning and the other mid-afternoon Wednesday through early evening Wednesday. The headlines depict the current thinking. Here is the current key factors for these two rounds of potential severe weather:

Wednesday Morning – Key Factors:

1.) Instability coinciding with the shear and turning in the atmosphere with the warm front

2.) How much instability we get if it can coincide with the shear and turning in the atmosphere

Wednesday Afternoon through early evening – Key Factors:

1.) Amount of heating and destabilization ahead of the cold front to allow for sufficient instability

2.) Timing of the cold front into the region augmenting the level of heating and destabilization

SKYWARN Activation is likely Wednesday. Self-Activation will be utilized in the morning and Ops at NWS Boston/Norton could be utilized for the Wednesday Afternoon/Evening timeframe. Another coordination message, either a shortened one or a complete coordination message depending on what time allows will be posted by 1230 PM Wednesday. Below is the NWS Boston/Norton Hazardous Weather Outlook, Enhanced Hazardous Weather Outlook and SPC Day-2 Convective Outlook..