jconsor

Satellite loops this Sunday morning show 99L has a small circulation. This is confirmed by two satellite wind estimates (ASCAT and microwave-based MIRS). Model guidance is playing catchup big-time with #99L, with deep convection and strong vorticity persisting for several days despite model forecasts that 99L would remain an open wave with little convection. 99L's small size is likely a big factor in this (we something similar before Oscar formed last year). Read my in-depth analysis of 99L and its potential to organize further late this week into this weekend in the western Caribbean and eventually BOC/GOM: https://hurricanehacker.substack.com/p/caribbean-cruisin

Hurricane Erin, despite weakening significantly in the past 24 hours, may have one more round of strengthening in its arsenal. With a fetch of tropical storm force winds extending out hundreds of miles into the ocean piling up water over three days of high tide cycles, water levels from NC to SE Virginia could rival levels during Dorian and Irene. The Delmarva Peninsula to southern NJ could see a top 5 water level on record as well. https://hurricanehacker.substack.com/p/too-close-for-comfort

Erin continues to remain on the southern side of forecast spread today, but that may not matter much for possible impacts from NC to SE New England. Will Erin re-intensify now that her eyewall replacement cycle is done? Starting to make about half of my posts paid this week, so I encourage all of you tropical freaks to subscribe and support my work so you can see all of my hurricane-related posts. https://hurricanehacker.substack.com/p/systematic-bias

@bugalou These graphics of NHC cone/track overlaid with Erin satellite loop are very helpful. Did you create this via an app or website? I am familiar with WeatherNerds satellite loops that allow overlay of EPS/GEFS members. The CIMSS storm-specific page allows overlay of the *current* NHC track, but doesn't dynamically update it every 6 hours as your loop did: https://tropic.ssec.wisc.edu/real-time/storm.php?&basin=atlantic&sname=05L&invest=NO&zoom=4&img=1&vars=111110000000000000000000&loop=0&llval=OFF

Thanks man! Appreciate the encouragement and positive feedback. I expect to post an update today.

Powerful Hurricane Erin continues to track on the southern edge of the model spread on Sat, as shown in the attached image. Erin's actual track in six hour increments is shown in the black X's, with NHC's main consensus forecast model TVCN shown in blue, with darker shades indicating more recent forecast model runs. You can see Erin made a notable bend to the left (turning from west-northwest to due west) in the past 12-18 hours and is currently about 50-75 miles south of consensus model forecasts from 24 hours ago. Here's an in-depth post I wrote on Fri describing my concerns that ensemble forecasts are underdoing W. Atl ridging, and explaining why US impacts can't be ruled out yet. It wasn't posted until now due to coming down with a stomach virus and some technical issues. My thoughts on Erin's track and potential US impacts haven't changed much since Fri. Would appreciate if you can take a look at the post and send me feedback (you can PM me here or write to [email protected]), as well as spread the word about my Substack. Thank you guys! https://hurricanehacker.substack.com/p/arrested-development

Tropical Storm #Erin continues trucking west and is showing signs of life after nearly two days of struggling. While a weakness in the western Atlantic ridge is a given, how quickly the ridge rebounds and what role an eastern US trough play could lead to some longer-term track intrigue. In-depth analysis and a parody of a 1970s R&B classic here: https://hurricanehacker.substack.com/p/losin-latitude

Please post the link for the vertical instability graphic. Thanks

ECMWF and Australian BOM models (amongst other seasonal models) suggesting a Central Atlantic NIno developing. This, along with portion of the very warm anomalies west of Europe gradually bleeding SW the Canary Islands and eastern tropical Atlantic, could help ramp up activity in the deep tropics, particularly west of 40W. https://x.com/yconsor/status/1930624747382964591

Hi Chuck, Interesting comparisons! I personally think using named storms to characterize active vs. inactive years is not particularly meaningful, given the human subjectivity and changes in NHC criteria over the years in terms of what is named. If we take the years with the most and least ACE since 1995, removing years that were El Ninos in the Apr-May timeframe (since they tend to be strongly correlated with -NAO), here are the most active years: 2020, 2005, 2004, 2003, 1999, 1996, 1995 The least active years: 2014, 2013, 2009, 2007, 2006 This year has some characteristics in common with the least active years (-MSLP anomaly from NW Territories of Canada to Greenland and +MSLP anomaly from the NW US to Hudson Bay and off the coast of the NE US). However, what is different from the inactive year composite, and closer to the active year composite, is the -MSLP from near Newfoundland to the central Atlantic near the Azores and then southward into the far east Atlantic and w. Africa. Additionally, the strong +NSLP from near the UK to Iceland is more similar to the active year composite. In short, a mixed bag, probably closer to inactive years but not a clear signal!

I was referring to highly unlikely possibility that so many of the hurricanes in both basins will become majors.

7 hurricanes and 5 majors in the Atlantic (and 6 and 5 in the East Pacific) is a rather comical outlook

In my view, it's mportant not to lump all La Ninas together. Modoki (central Pacific-based) La Ninas are notably different from traditional (East Pacific-based) Ninas. This has big implications for the level of Atlantic TC activity and where in the basin it tends to be focused. This year is more likely to end up a Modoki La Nina, with cooler water relative to normal focused in the central Pacific: https://x.com/yconsor/status/1927306239920283821

Thread explaining why I think chances for tropical development in the NW Caribbean and Gulf of Mexico ramp up significantly around Jun 4-10. https://x.com/yconsor/status/1926690131181731976

After not being much of a factor from 2019-24, looks like the N. Atlantic warm hole, a pool of relatively cooler water south of Greenland, is returning and should remain through peak hurricane season. This tends to ramp up the risk for E. Coast hurricanes, particularly slow-moving ones: https://x.com/yconsor/status/1925494559032668254