Isolated Flash Flooding Possible Across Central Vermont

Champlain Valley Weather Discussion:
     Currently light to occasionally moderate rain is overspreading the area from West-Southwest to East-Northeast. The steadiest rains at this current time are over Northern New York, but this batch of rain is expected to move into Northern Vermont within the next hour or two.

     The National Weather Service has continued the flood watch for the entire area. Although flooding is unlikely across Northern Vermont. The greatest risk of flooding will be across Central Vermont, how much flooding in general is going to depend on how much more rain develops, and that is looking like a tough call.

     Models continue to indicate generally a half to three quarters of an inch of additional rainfall. With isolated amounts up to 1.25 inches. Now the problem is, the low pressure center is moving north, and those of us not currently in the warm sector, will be by later this evening. This will result in some instability, and with a cold front approaching from the west by late tonight, and into tomorrow, the risk for thunderstorms arise. Precipitable water values are in the 1.4 - 1.7 range, and if any thunderstorms were to occur, this would result in some significant downpours. Any slower moving storms that develop have the potential to easily produce rainfall in excess of 1 inch per hour. That amount of rain combined with current Flash Flood Guidance values generally ranging in the 1.00-1.50 inch range, the possibility for some isolated flash flooding exists, especially across Washington, and Addison Counties. Also the Hydrometeorological Prediction Center has placed nearly all of Vermont under a slight risk for exceeding flash flood guidance. With that in mind, I have changed my suggested alerts map. I have put up a Flash Flood Watch, instead of a regular Flood Watch. I do want to urge though that if any Flash Flooding should occur it will be isolated, as instability should be marginal for thunderstorms. I also continue to exclude the Border Counties of Vermont, and New York, as not enough rain has fallen, to cause river flooding, nor will enough rain fall across those counties to cause river flooding. Also Flash Flooding is much less likely at this time, as once again not enough rain has fallen to elevate the risk for flash flooding. (Updated Maps Below.)