1:00 PM | Heavy rain threat in the Mid-Atlantic region late Sunday into Monday with strong cold front; potential tropical troubles later next week/weekend

Discussion

Heavy rain threat for the Mid-Atlantic: The season’s first official heat wave (defined as 3 days or more of 90 degree high temperatures) may come to an end with quite a bang in the Mid-Atlantic region late Sunday into Monday. A strong cold front will reach the east coast by then bringing with it the likelihood for heavy showers and strong-to-severe thunderstorms as the cooler air clashes with the current well-established hot and humid air mass. This is the same frontal system that is creating severe weather today in the nation’s midsection and likely tomorrow in parts of the Midwest and Ohio Valley. There is the potential in the Mid-Atlantic for an inch or more of rain from late Sunday into Monday, but then nice weather will return to the region for Tuesday and Wednesday with high temperatures generally in the pleasant 70’s.

Potential tropical troubles: The Atlantic Basin hurricane season officially begins tomorrow, June 1st, and, as if right on cue, there very well could be some tropical troubles later next week/weekend over the Gulf of Mexico. Multiple computer forecast models suggest that there will be a tropical disturbance over the Gulf of Mexico later next week/weekend and there is some supporting evidence for this outlook.

To begin with, in a somewhat strange turn of events, the remains of a Pacific Ocean tropical storm named Barbara have now spilled over into the Gulf of Mexico and its lingering moisture field will likely play a role in the potential development in that region over the next several days. By the way, if indeed a named tropical storm from the Pacific Ocean were to redevelop in the Atlantic Basin (Gulf of Mexico, Caribbean Sea, Atlantic Ocean), it would get renamed to one of the Atlantic Basin designated names on this year’s National Hurricane Center list.

The second signal favoring the possibility for tropical troubles later next week/weekend is called the Madden-Julian Oscillation (MJO) index which tracks a tropical disturbance that propagates eastward around the global tropics with a cycle on the order of 30-60 days. The MJO has wide ranging impacts on the patterns of tropical and extratropical precipitation, atmospheric circulation, and surface temperatures around the global tropics and subtropics. Research has found that the location of the MJO, or phase, is linked with certain temperature and precipitation patterns around the world. The very latest MJO forecast propagates the MJO into phases 2 and 3 come early June (5th to 10th) and studies have shown that these particular two phases tend to favor tropical activity in the Atlantic Basin. Updates next week on this potential tropical threat.