Severe Thunderstorms & Isolated Tornadoes Possible Into Tonight

National Weather Service Storm Prediction Center Special Mesoscale Discussion (Click HERE To View Details!)

Champlain Valley Weather Discussion:
     Currently, things are quieting down across the region other than some light to moderate rain across Vermont, mainly east of the Champlain Valley. Things may become interesting overnight as the atmosphere remains unstable. The threat for severe weather overnight, is a rare occurrence across the Northeast United States, as we don't have enough sub-tropical or tropical moisture to make up for the daytime heating, that produces our primary instability. With that in mind, the Storm Prediction Center, has issued a Mesoscale discussion stating that the possibility for continued severe thunderstorms will be possible overnight, and to make it even more rare, the possibility of isolated tornadoes. The Greatest threat for continued severe weather will be across Northern New York, Western, and Central New York, south into Pennsylvania. This situation will be monitored closely, and if a Severe Weather Watch is issued for our area I will post that immediately.

     National Weather Service Doppler Radar is currently indicating storms developing along the St. Lawrence River Valley, and further South, and West into Ontario, Canada, and Buffalo, New York. One area of showers and thunderstorms that will be concern to our area, are a line of storms currently just west of St. Lawrence County, in Canada right now. Doppler radar is indicating that this line of thunderstorms has the potential to produce penny to nickel size hail. This storm is approximately 30 miles West of Potsdam, New York. No Severe Thunderstorm Warning has been issued yet, but that may change soon. This area of storms will be watched closely as they progress across Northern New York, and possibly into Western Vermont. Stay tuned for possible further updates.

Severe Thunderstorm Watch #533 In Effect For Parts Of Our Region

Overview: The National Weather Service, Storm Prediction Center out of Norman, Oklahoma, has issued Severe Thunderstorm watch #533 for parts of our region. Hail to 2 inches in diameter, and thunderstorm wind gust to 70MPH are possible in the strongest of storms. (Click on either map above for alert details)

Champlain Valley Weather Discussion:
     Today looks to be rather interesting. Significant sunshine was able to break through the clouds this morning, and destabilize the atmosphere significantly from the Champlain Valley, and points west. Currently the most unstable atmosphere is over the Champlain Valley itself, where sun has been prevalent much of the day. Across the Champlain and St. Lawrence Valleys, MUCAPE values range from 900 j/kg to 1500 j/kg, with SBCAPE values ranging from 800 j/kg to 1000 j/kg, and LI's in the -1 to -4 range. All together what this is indicating is that the atmosphere is unstable, and the likelihood for thunderstorms is fairly high, with severe thunderstorms possible.

     The primary severe threat will be large hail, due to freezing heights being slightly lower then normal due to the upper level low pressure system over the Great Lakes region. Secondary threat will be damaging winds, and the final threat being the possibility of a very brief tornado, due to some rotation.

     Aside from the severe thunderstorm aspect, overall the main threat today, will be for isolated Flash Flooding. With Precipitable water values in the 1.0 - 1.5 range today, and the possibility of training/ backing thunderstorms, it wont take much to get storms to drop 1-2 inches in a short period of time. Some isolated storms could even produce up to 3 inches! The greatest threat for any Flash Flooding would be across the higher terrain of Clinton, and Essex Counties in New York, and the Western slopes of the Green Mountains in Vermont, especially where areas in Vermont received 1-2 inches of rain yesterday, leading to lowering Flash Flood Values. With this in mind, I have extended the Flash Flood Watch on my "Suggested Alerts" map, and it now covers the entire Champlain Valley coverage area. The reason I expanded it west, is because that's where storms should be most numerous, however any slow moving storms that can push into the Western Slopes, and Eastern Vermont will have the potential to produce isolated Flash Flooding.

     Aside from the Severe weather details, recently Champlain Valley Weather has had a team put together to do some Storm Chasing. Currently we do not have computer access in the Chase Vehicles so we have our own Storm Tracker in which we stay in frequent contact with, so we are sent to the hot spots. With all this in mind we urge you to view the site frequently, as days when we are out chasing we will send texts direct to the Champlain Valley Weather site so you know exactly whats going on out on the roads. Today we plan on Chasing from 3-8PM if storms being to develop, so stay tuned to the site for Chase posts, with live from the scene damage or flooding photos!