During the past 2 months an arc of persistent heavy rainfall has extended from the western half of the tropical Indian Ocean northeastward across parts of India and northeastward from there into China and more recently Japan. The moderate-strength and stalled Madden Julian oscillation is the catalyst.

A Northeast Corridor heat wave begins today. An Excessive Heat Watch is in effect for parts of southern New England valid through 8PM EDT Monday. Heat advisories are in effect for much of the remainder of New England south to the New York City area. Today’s hot weather is without high humidity. However, high dew points arrive tomorrow forcing widespread 105F heat index (or higher) which will last into Tuesday.

An ideal environment for intensification - low shear and very warm surface water - causes Hanna to become a hurricane slamming the south coast of Texas just south of Corpus Christi this afternoon.

Does another heat wave follow the current episode for next weekend? ECMWF says yes and forecasts a stronger event than currently taking place. The GFS is not nearly as hot. The question is whether the hot air source region in the Central U.S. pulses eastward (or not). GFS says no while ECM is (vigorously) yes! The precedent is set as last week’s Midwest heat wave has shifted into the East now. A second event is likely and given peak summer heat the next event could be hotter.