Northeast: Heat and Humidity Return Sunday and Monday

Friday morning

The following video outlines the forecast for the Labor Day weekend across the Great Lakes and Northeast. The main theme in the Northeast will be the increase in warmth and humidity. The greatest uncertainty lies in the timing and distribution of showers and thunderstorms on Sunday and Monday.

The following map shows the projected upper air flow for next Wednesday evening. Note how the lines are closer together over the northern Rockies and upper Great Lakes than is the case farther south. The closer together the lines, the stronger the flow. That zone (which includes the jet stream) is usually on top of the area with the strongest temperature contrasts, so it is where we find the main storm tracks and the cold and warm fronts. Anyway, after all that, the point is that zone will be north of most of the eastern half of the country. It will be very warm to hot south of the jet stream. However, weakening cold fronts can advance south of the jet stream. then return north as the next disturbance in the flow approaches.