Wednesday, May 08, 2013

High Pressure Yields Warmer Maine & Washington Than Florida & Arizona

What do you get when you have high pressure aloft over the southern parts of Canada and the northern parts of the US?  A weather pattern that yields warmer temperatures in Washington State and Maine than in Florida and Arizona.

Upper level lows spinning over the Southwest and the Southeast are helping bring moisture and cooler weather than usual for May to both locations while the northern tier of the nation is warm for this time of the year.  The main jet stream, which we pointed out yesterday was over Northern Canada, had been generally preventing these upper level disturbances across the southern parts of the country from moving too quickly.  However, the ridge of high pressure that has built in over Southern Canada has brought near 90 degree weather as far north as Edmonton (88 on Monday).

Yesterday at 5 PM eastern time temperatures were in the upper 80's in Washington State (it was 89 in Yakima, WA) while it was "just" 82 in Phoenix and just in the 80's in much of Texas.  Montreal, at 82 degrees, was warmer than the 77 that it was in Miami.  That same 82 degree reading in Caribou, ME, nearly outdid the high in Miami (85) and equaled the high in Orlando, while beating Tampa's high (78).

The pattern later this week will gradually evolve into a more "typical" spring pattern as a trough of low pressure develops in the middle of the country and pushes east, with a strong ridge of high pressure building across the western half of the nation.  The days of hotter weather in Caribou than Tampa should be a thing of the past, at least for a while.