2008 Spring Flood Situation

[CanisLupusArctos]

This thread is for flood information & discussion as the spring meltdown finally appears to be kicking into high gear.

We start with about a foot of dense snow on the ground around the lake, which is a lot better than the situation we had 3 weeks ago but still more threatening than last year at this time.

Of greater concern is what's in the mountains (more snow than anyone has seen there in decades.)

The last couple days have been in the 50s which has accelerated melting of the snow. The lake level has responded but so far the dam seems to be letting it out fast enough to prevent rapid rising of the lake.

Coming this weekend we have a possible major rain storm on the way for both days, and the next several days look wet. At the moment, however, it looks like we might get spared from flooding by something no one really wants to see more of.

It appears the storm is going to give us more of its cold side than warm side this weekend. If this situation pans out, it will spare us the heaviest rainfall on its warm side while keeping temps in the mid-30s... these near-freezing temps would keep snow from melting quickly enough to push the area's rivers above flood stage this weekend.

At the same time it may produce snow above 1500' elevation (just below Mt. Major's summit.) This would definitely keep rapid snowmelt from occurring in the Mountains.

Even with this less-rainy side of the storm, we may still get an inch of rain below 1500', so we're still very close to a flood situation for this weekend. Therefore it would be a good idea to keep watching weather reports in case flooding suddenly starts to look more likely.

Beyond this weekend I think we'll still be walking a fine line between "flood" and "no flood" (especially on the area's rivers and streams) until the spring melt has passed its max.

If the rivers downstream of Winnipesaukee's dam approach flood stage, we may see the dam drastically reduce outflow, which could cause a rapid rise in lake level. I don't think it would take much more than an inch of widespread rain to make that happen, especially if combined with warm temps. We also need to watch rainfall amounts for south of the lake, because if the area from Concord-southward gets a rainstorm heavy enough to cause river flooding there, it might necessitate the closing of Winni's dam.