A secondary cold front slid past today, and temperatures fell despite the bright sun. The wind was gusty and very dry. Despite some talk of big thunderstorms yesterday, the primary front passed without much ruckus, and in all we only got a tenth of an inch of rain. That barely made any puddles, and dried up with somewhat amazing speed. The swift evaporation created a shallow overcast of flat, purple cumulus, and robbed us of our warming sun. As I shuddered in the garden I figured I’d best zip home and see if we are in for a frost.
The map’s isobars seem to show a flow straight down from Hudson bay.
Hudson Bay is still nearly entirely ice-covered.
The most recent storm even laid down a swath of snow-cover across Ontario. Most of the smaller lakes are still frozen up there, and there is even a bit of ice left in the easternmost part of Lake Superior, though it is nearly June. No warmth is in winds from up there.
Usually the fact the foliage is out does something that prevents frost. The leaves exude moisture when the winds die, or some such thing. So usually I’d ignore the GFS-based NWS forecast, which has a frost warning. They tend to be too cold. However it is so bone dry that I’m nervous. The thirsty trees may have less ability to resist frost than usual.
The air temperatures are still up in the mid 50’s, (12.8° Celsius) but the dew point is down to 36°, which reduces the relative humidity to around 30% . That is so dry my skin feels sort of chapped by the wind. New Hampshire has a class three fire danger, which is high. The very afternoon you might like a fire to warm by you’d be a Tom Fool to start one, because the wind could whip across the field into the neighbors yew bushes, and I don’t think they’d like that.
I’m not going to take any chances. I have piles of grass clippings in the garden, from mowing the lawn, and I think I’ll bury my tomato plants in the dry grass, just to be on the safe side. I’d complain about the extra work, but it’s my own fault for trying to get away with putting tomatoes in early. The old-timers are laughing at me from the clouds they sit on, as they never trusted New Hampshire springs, and never bothered much with their gardens until May 31.
Its odd to hear fire dangers and freeze dangers in the same forecast. The only good news is that over at the Weatherbell Site Joseph D’Aleo sees signs the pattern will get wetter next week. I don’t see a sign of it yet, but here’s to hoping.