Friday Weather

ICAP Weather Commentary

Friday July 15, 2011

The heat advisories, heat warnings and heat watches have expanded to include virtually all of the Plains and into the Midwest. The size and scope of the potential combined with the time of year (direct mid summer) puts this hot spell into a significant category. The heat should expand east of the Mississippi next week. A check this morning of dew point temperatures (measure of moisture and humidity) has them widespread in the low 70's across the corn belt. They were around 80 last weekend when the heat index was 115 in places. I expect them to rise a few degrees over the weekend. The most active weather right now is over the SE and Gulf coast. With the ridge so strong and pushed north it allows for a tropical wind flow from the east and SE. That and a decaying cold front brings the potential for some heavy rain the next couple of days. That same east wind from high pressure just off the North Atlantic coast keeps those east of the Appalachians and along the gulf near normal on temperatures or maybe even a degree below in spots into early next week. The strongest cool area remains the west coast as an upper low remains in place west of the strong high.

Day 6-10 discussion:

Some expansion east of the heat ridge is seen next week. This should mean widespread highs in the 90s and afternoon heat indices to 100-105 even to the east coast late next week. The Plains and Midwest still look hot, but possibly a little less humid. Energy from the western low could reach parts of the Plains late in the period but the relief is minimal. I would place at least 80% of the country warmer than normal and perhaps 1/3 well above normal including some highly populated areas of the Midwest and Great Lakes. Out west, the southern part of the cool upper low should weaken, but below normal air remains in the NW.