A strong cold front diving through western caNADA will begin plunging through the northern tier, bringing strong winds and low humidity ahead of the approaching front which will lead to a heightened risk of fire weather across southern Montana and into parts of Wyoming and Idaho. Heat will continue in the southwestern U.S. where daytime temperatures will continue to soar well into triple digits. Monsoonal moisture over the central Great Basin and Central/Southern Rockies should produce some scattered late afternoon/early evening thunderstorms across the region.
A weak surface wave will track through the Ohio Valley on Tuesday, reaching northern New England by early Wednesday. Scattered showers and thunderstorms will be possible ahead of the trailing cold front pushing towards the Eastern Seaboard. The tail end of the front should linger over north Texas the next few days and should help produce some much needed rain over Oklahoma and Arkansas.
There is a slight risk of severe thunderstorms across eastern Pennsylvania, New Jersey, much of Maryland, Delaware and northern Virginia. Yesterday, there were about 50 reports of high wind and hail with most of the reports from Montana, Mississippi, Alabama and Tennessee.
Upper ridging over the southwestern U.S. will keep temperatures above normal across the region. Excessive Heat Warnings remain in effect for portions of the Desert Southwest and valleys of southern California where daytime temperatures will yet again climb to triple digits.
At 200 AM PDT the center of Tropical Storm Hector was located about 205 miles west-southwest of Socorro Island or about 435 miles southwest of the southern tip of Baja California. Movement was toward the west near 6 MPH. A west-northwestward motion at a slightly slower forward speed is expected during the next couple of days. Maximum sustained winds were near 45 MPH with higher gusts. Some weakening is forecast and Hector could become a tropical depression by Wednesday night.