7:00 AM | **Heavy rain threat later this week and watching an east coast tropical system**

6-Day Forecast

Today

Partly sunny, warm, a bit more humid, highs in the mid 80’s

Tonight

Mostly cloudy, mild, muggy, lows in the mid-to-upper 60’s

Tuesday

Partly sunny, hot, humid, chance for late day showers and thunderstorms, near 90

Tuesday Night

Mostly cloudy, mild, muggy, chance for showers and thunderstorms, near 70

Wednesday

Partly sunny, hot, humid, PM showers and thunderstorms likely, some of the rain can be heavy, low 90’s

Thursday

Partly sunny, quite warm, PM showers and thunderstorms likely, some of the rain can be heavy, upper 80’s

Friday

Partly sunny, cooler, chance for showers and thunderstorms, near 80

Saturday

Mostly sunny, pleasant, near 80

Discussion

Yesterday's high failed to officially reach 90 degrees at Philly Int'l Airport in South Philadelphia and today - the last day of the month of June - is also likely to feature high temperatures holding in the 80's. This would mean we have made it through June with only three 90+ degrees this spring and summer season so far and that would be the fewest amount of 90+ degree days through the month of June since 1985. July, on the other hand, could very well begin with two or three straight 90+ degree days (Tuesday, Wednesday, and an outside chance on Thursday). The three days that we did reach 90+ degrees at Philly Airport all occurred in this month: 93 on 6/17, 94 on 6/18, and 90 on 6/25.

High pressure controlled our weather through the weekend providing us with comfortable temperatures and humidity levels from its location just off the Northeast US coastline. As the high drifts farther off the coast, a southwest flow of increasingly warm and humid air will develop in the I-95 corridor and this, combined with an approaching cold front from the west, will raise our chances for showers and thunderstorms as we progress through the week and some of the rain is likely to be heavy late Wednesday and late Thursday. At the same time, it appears that a tropical storm will form over the next few days just off the southeast US coastline. This system - possibly to become the first named tropical system (Arthur) - is likely to ride northeastward along the east coast over the next several days. Currently, it appears that this system could directly affect the Outer Banks of North Carolina late this week and then could slide just to our east at the end of the week. Stay tuned.

Video

httpv://youtu.be/Y2yzv35j0RY