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    Elliot Abrams

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    Great Lakes to Northeast Heat Wave Stays Until the Weekend

    July 16, 2013; 5:37 AM ET

    Tuesday 7:15 a.m.

    My video shows the heat wave setup for the northeastern third of the country and explains why the heat wave should be cut down during the coming weekend.

    The map showing today's upper air flow pattern includes a huge high pressure area aloft centered over Ohio. This kind of high is a classic signature for a heat wave. Note how the prevailing westerlies are pushed well north into Canada.

    Most of the time when a big ridge is in charge, there is little or no precipitation. Air sinks in high pressure areas, and sinking air becomes warmer and drier. Yesterday, thunderstorms were most numerous in the Southeast and back into Texas, well south of the high pressure center. However, the hot air mass is so humid that some thunderstorms popped in response to intense ground-level heating right into the central part of this high pressure area.

    This forecast map of the upper air flow for Saturday shows a big high is gone and the westerlies are expanding southward through the Great Lakes region. This strongly suggests a cold front will be moving into the Northeast with thunderstorms (perhaps severe) followed by an end to this heat wave.

    The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com


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