The core of an old occluded extratropical cyclone was designated at Invest 91L on Monday.\u00a0 At 8:00 a.m. EDT on Monday the center of Invest 91L was located at latitude 32.7\u00b0N and longitude 47.1\u00b0W which put it about 1180 miles (1900 km) east of Bermuda.\u00a0 Invest 91L was moving toward the south-southeast at 7 m.p.h. (11 km\/h).\u00a0 The maximum sustained wind speed was 60 m.p.h. (95 km\/h) and there were wind gusts to 75 m.p.h. (120 km\/h).\u00a0 The minimum surface pressure was 986 mb.<\/p>\n
A large surface high pressure system near Europe is blocking the northeastward movement of an extratropical cyclone over the North Atlantic Ocean.\u00a0 The extratropical cyclone proceeded through the normal stages of development and it matured into an occluded low during the past few days.\u00a0 The occluded low has been nearly stationary over the Atlantic Ocean during that period.\u00a0 Drier air wrapped around the western and southern sides of the low and the occluded front was pushed east of the core of the circulation.\u00a0 More showers and thunderstorms formed closer to the center of circulation and a well defined, tightly wound circular center is apparent on the visible satellite images this morning.\u00a0 The appearance of the tight circular center prompted the designation of Invest 91L.<\/p>\n
Invest 91L is in an environment that would not be favorable for the classical development of a tropical cyclone.\u00a0 It is over water where the Sea Surface Temperature (SST) is around 20\u00b0C.\u00a0 However, it is possible for a transition to a tropical or subtropical cyclone to occur over colder SSTs if the air aloft is also cold enough to allow thunderstorms to develop.\u00a0 It appears that there may be enough instability to allow for thunderstorms to form near the core of Invest 91L.\u00a0 There is currently a cold cut off low associated with the occluded surface low over the top of Invest 91L.\u00a0 Cold temperatures in the upper levels mean that Invest 91L is still an extratropical cyclone.\u00a0 However, the upper low is also rotating in the same direction as the surface low.\u00a0 So, there is not very much wind shear over the top of Invest 91L.<\/p>\n
Invest 91L is forecast to move slowly southward during the next several days.\u00a0 As it moves south, Invest 91L will gradually move over warmer water.\u00a0 If more thunderstorms develop around the center of circulation and a warm core starts to develop, Invest 91L could be classified as a subtropical or tropical cyclone.\u00a0 Since the maximum sustained wind speed is 60 m.p.h., Invest 91L could be classified as a subtropical or tropical storm if that happens.<\/p>\n
The large surface high pressure system is forecast to continue to block the movement of Invest 91L.\u00a0 Invest 91L is forecast to moved slowly toward the south or south-southeast during the next day or two.\u00a0 The system could meander over the central North Atlantic Ocean during much of the week.<\/p>\n","protected":false},"excerpt":{"rendered":"
The core of an old occluded extratropical cyclone was designated at Invest 91L on Monday.\u00a0 At 8:00 a.m. EDT on Monday the center of Invest 91L was located at latitude 32.7\u00b0N and longitude 47.1\u00b0W which put it about 1180 miles (1900 km) east of Bermuda.\u00a0 Invest 91L was moving toward the south-southeast at 7 m.p.h. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,2],"tags":[375,660,661,31,374,322],"_links":{"self":[{"href":"https:\/\/jayhobgood.com\/index.php?rest_route=\/wp\/v2\/posts\/3851"}],"collection":[{"href":"https:\/\/jayhobgood.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jayhobgood.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jayhobgood.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jayhobgood.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3851"}],"version-history":[{"count":1,"href":"https:\/\/jayhobgood.com\/index.php?rest_route=\/wp\/v2\/posts\/3851\/revisions"}],"predecessor-version":[{"id":3852,"href":"https:\/\/jayhobgood.com\/index.php?rest_route=\/wp\/v2\/posts\/3851\/revisions\/3852"}],"wp:attachment":[{"href":"https:\/\/jayhobgood.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3851"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jayhobgood.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3851"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jayhobgood.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}