Pittsburgh will be faced with a couple of rounds of severe weather into Tuesday evening.
A surge of warm and humid air following the holiday weekend will set the stage for severe thunderstorms.
The afternoon and evening hours are when the strongest thunderstorms will rumble and threaten to cause some damage and hazards to residents.
Powerful wind gusts are the main hazard with the strongest storms through Tuesday. A small number of the storms can also bring hail and flash flooding.
Any thunderstorm each day can also produce frequent lightning. Remember, you are close enough to get struck by lightning if you hear thunder.
After a lingering shower or thunderstorm Wednesday morning, humidity will lower in the afternoon as drier air works into western Pennsylvania.
A comfortable stretch of days will follow for Thursday and Friday, with skies no worse than partly sunny and temperatures rising to around the 80-degree mark.
Unsettled weather for the extended Labor Day weekend will be across the Southeast, Upper Midwest, northern Rockies and the Four Corners.
Tropical Depression 14-E is several hundred miles southwest of Mexico and is expected to strengthen slowly into a tropical storm.
A stormy weather pattern will prevail through September across much of southern South America.
While lulls in tropical activity in the Atlantic will continue, a rapid end to the hurricane season in September does not always occur during an El Niño.
The combination of moisture from Erika and a non-tropical system will drench areas from Florida to the South Carolina coast through the middle of the week.
Heat will be erased by an autumnlike air mass across parts of northern Europe.
Mecca, CA (1950)
126 degrees - highest ever for U.S. in Sept.
East Coast (1775)
Matecumbe Key, FL (1935)
Labor Day Hurricane hit Florida. Pressure at Matecumbe Key dipped to 26.35"/892.3 mb. Most intense hurricane ever to hit the U.S. with 200-mph wind. Tide of 15 feet; 408 dead.