1:15 PM (Wednesday) | *An impressive cold shot for the central and eastern US later next week…a quieter period for the tropical Atlantic (albeit temporary)*
Paul Dorian
An impressive cold air outbreak reaches the central and eastern US by later next week. Map courtesy NOAA, tropicaltidbits.com
Overview
It looks like the month of October will begin with quite an impressive cold air outbreak in the central and eastern US as a deep upper-level trough forms overhead. The strong surface cold front that will be at the leading edge of the cold air mass is likely to reach the east coast at mid-week and colder-than-normal conditions will last right into the first full weekend of October. On the tropical scene, it looks like the Atlantic Basin may actually have some quiet time – at on a temporary basis - after a very active stretch in the month of September.
An outbreak of much colder-than-normal air in the central and eastern US later next week will be associated with a deep upper-level trough. Map courtesy WSI, Inc., NOAA
Cold air outbreak
It has been quite cool in the Mid-Atlantic region during the past week or so with many spots recording low temperatures in the 40’s on four consecutive nights and this hasn’t happened in the month of September for many decades in some of these areas. This recent stretch of cooler-than-normal weather in the Mid-Atlantic region has also resulted in many record or near record lows (e.g., Allentown, PA, Wilmington, DE on Tuesday). Looking ahead, an even colder air mass is destined to reach the central and eastern US later next week as a deep upper-level trough forms overhead. This cold air outbreak for the central and eastern US will roughly coincide with the calendar transition from September to October with the strong cold front at the leading edge arriving at the east coast around the middle of next week. Once the colder-than-normal conditions develop next week it looks like they’ll stick around right into the first full weekend of October. At the same time the central and eastern US chill down, high pressure ridging will intensify along the west coast of the US. It’ll become warmer-than-normal in the same western US areas that experienced numerous wildfires in recent days. In fact, this unfolding weather pattern suggests the threat of wildfires will likely go back up significantly in much of the western US as we go through the first part of October.
Tropical Storm Beta resulted in significant rainfall amounts in eastern Texas during the past few days. Map courtesy NOAA
The tropical scene
The remains of Tropical Storm Beta now near the Texas/Louisiana border continue to push slowly to the northeast and its leftover moisture field will increase chances of significant rainfall in the Tennessee Valley during the next couple of days. In addition, the leftover moisture from Beta should reach the Mid-Atlantic region by the weekend and it’ll result in an increased shower threat there from later Friday into the upcoming weekend.
A buoy just south of Nova Scotia recorded this steep drop in pressure and significant wave heights as a result of the passage of “post-tropical” Teddy. Data courtesy NOAA/NDBC
Meanwhile, “post-tropical” Teddy is currently located over the far northeastern part of Nova Scotia with maximum sustained winds of 60 mph and a rapid movement to the NNE at 26 mph. “Post-tropical” Teddy pounded Nova Scotia in the overnight hours and during the early part of Wednesday with heavy rainfall, strong winds and high waves along the southern coastline. This “post-tropical” system will continue to head to the northeast in coming days and it’ll get absorbed by another storm system way up north and actually contribute to accumulating snow across southern Greenland and northeastern Canada. In fact, there is the chance of significant snow in the southeastern part of Greenland between tomorrow and the later stages of the upcoming weekend.
“Post-tropical” Teddy will contribute to some significant snow in coming days across southern Greenland and northeastern Canada. Map courtesy NOAA, tropicaltidbits.com
The good news with respect to the tropics and the Atlantic Basin is that it actually looks like there will be a relatively quiet stretch as we close out September and begin the month of October. This quieter stretch in the Atlantic Basin will very likely be only temporary and at the same time, the Pacific Basin is likely to become much more active after a very subdued month of September in the world’s largest ocean.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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