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for additional charts check out Mike's Weather .. https://spaghettimodels.com/
credits - in part our Tropical Weather Update today has been put together with data from
Crown Weather Services, Mike's Weather Page  and NOAA

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2021-09-24 - Tropical Weather Update - this report is all about Hurricane Sam ..
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Hurricane Sam - Sam is now a hurricane and rapid strengthening is expected to continue .. Sam continues to move on a westward track and this general westward motion is expected to continue into Saturday as the hurricane is guided by the flow of a high pressure ridge to the north ..
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bottom line - Hurricane Sam - we STRONGLY urge those of you in the Leeward Islands, Virgin Islands and Puerto Rico to keep an extremely close eye on Sam in the coming days ..
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heads up - check our buoy reports in your area for wind speed and wave heights .. if you are not getting our buoy weather reports sign up NOW .. click here to sign up ..
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note - the next tropical weather discussion will be issued about midday on Saturday ..
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the end - of our recap for now .. you can stop reading now unless you are interested in the rest of the story ..
additional details .. see below ..
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Hurricane Sam
11:00 am EDT Statistics ..
Location: 11.5 North Latitude, 42.2 West Longitude or about 1470 miles to the east-southeast of the Northern Leeward Islands..
Maximum Winds: 75 mph ..
Minimum Central Pressure: 993 Millibars or 29.33 Inches ..
Forward Movement: West at a forward speed of 15 mph ..
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Hurricane Sam - Sam has been rapidly strengthening throughout the last 12-18 hours or so .. satellite imagery today indicates that Sam has a small, but well developed inner core .. there are some dry slots noted between the core and the outer bands and there seems to be some competition between a band of convection to the north of Sam and the hurricanes inner core .. once this band weakens and the entire system becomes more round in its overall presentation, it will likely strengthen much quicker than what we are seeing right now ..
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track - Sam continues to move on a westward track and this general westward motion is expected to continue into Saturday as the hurricane is guided by the flow of a high pressure ridge to the north ..
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looking ahead - the hurricane is expected to turn more to the west-northwest from later Saturday into the first half of next week as it reaches a weakness between two high pressure ridges .. as Sam approaches the northern Leeward Islands during the middle part of next week, an upper level trough of low pressure will move into the western North Atlantic and this should cause Sam to turn more to the northwest ..
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model guidance - the big questions are how quickly will the turn to the northwest occur and how close will the hurricane get to the northern Leeward Islands ..
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GFS ensemble model guidance - shows a much faster turn to the northwest than what the European ensemble model guidance shows .. this leads to a huge difference in how close Sam gets to the northeastern Caribbean with the GFS ensemble model guidance showing no impact at all ..
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European ensemble model guidance - shows at least tropical storm conditions and very possibly hurricane conditions for the northern Leeward Islands .. an analysis of the steering winds around Sam right now shows a wind pattern that would fit closer to the European model rather than the GFS model ..
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UFFDA - the eye of Hurricane Sam may pass just barely north and east of the northeastern Caribbean Islands on Wednesday night and Thursday .. this could be close enough to bring hurricane conditions to Anguilla, St. Martin and Sint Maarten late Wednesday night and Thursday morning .. the rest of the northern Leeward Islands and the Virgin Islands may be close enough to Sam to receive tropical storm conditions on Wednesday night and Thursday morning .. its also possible that Puerto Rico may be far enough away from the center of Sam to receive no adverse effects at all .. it should be noted that this is still a 5-6 day forecast and a lot can change between now and the middle part of next week ..
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looking way ahead - the weather pattern for late next week and beyond is extremely chaotic as there is likely to be many different moving pieces around Sam helping to steer it one way or another.
One weather feature that were watching is the interaction between a ridge of high pressure over the Atlantic and a trough of low pressure moving into the northeastern United States. Some of the guidance suggests that this trough will kick far enough east to help push Sam out into the open Atlantic after threatening or directly impacting Bermuda. Other guidance forecasts that the trough of low pressure may hang back a little and try to amplify some. Should this occur, it could lead to the trough capturing Sam causing it to try to slingshot back towards New England and Atlantic Canada ..
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bottom line - the part of the coastline that may really need to watch Sam for possible impacts next weekend is Long Island, New York, New England and Atlantic Canada, Fortunately, we have A TON of time to keep an eye on this ..
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strength - the environmental conditions are expected to be favorable for additional rapid strengthening through Saturday as the hurricane will be moving over very warm ocean waters within a low wind shear environment .. the latest SHIPS rapid intensification index shows a 41 percent chance that Sam could be a 105 mph hurricane by this time tomorrow and a 28 percent chance that Sam could strengthen into a 125-130 mph hurricane by tomorrow evening .. this means that we think that it is very likely that Sam will be a major hurricane by Saturday night and could be at about a 130-135 mph hurricane by Sunday night into Monday .. beyond this its possible that the environment could become a little less favorable with 10-15 knots of wind shear affecting Sam .. this could cause the hurricane to level out or even weaken a little during next week .. either way though, Sam is very likely to be a major hurricane for several days beginning tomorrow ..
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heads up - The Leeward Islands, Virgin Islands and Puerto Rico .. we still think that Sam poses a significant hurricane threat to the northern Leeward Islands and especially the islands of Sint Maarten, St. Martin and Anguilla, as well as the US and British Virgin Islands for around Wednesday into Thursday of next week. Sam may end up staying too far north to bring adverse effects to Puerto Rico. With that said, those of you on the island of Puerto Rico should also very closely monitor Sam as the track forecast may shift around in the coming days ..
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bottom bottom line - we STRONGLY urge those of you in the Leeward Islands, Virgin Islands and Puerto Rico to keep an extremely close eye on Sam in the coming days ..
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heads up - check our buoy reports in your area for wind speed and wave heights .. if you are not getting our buoy weather reports sign up now .. click here .. subscribe to receive our reports ..

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Our Tropical Weather reports - for the most part are put together only during tropical weather season .. our reports are based on a number of online sources and are based on our past experience dealing with tropical weather .. we also occasionally include non-tropical weather that would affect the area / footprint that we cover .. 
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for more details check out
Crown Weather Service at - http://crownweather.com/index.php/discussions/cws-plus-weather-discussions/ .
NOAA at - http://www.nhc.noaa.gov
Mike's Weather Page - http://www.spaghettimodels.com/
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disclaimer - all forecasts herein are made to the best ability of the forecaster .. however, due to standard forecasting error, these forecasts cannot be guaranteed .. any action or inaction taken by users of this forecast is the sole responsibility of that user ..

 

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