Track: https://www.nhc.noaa.gov/refresh/graphics_at3+shtml/?cone#contents Satellite floaters: https://www.star.nesdis.noaa.gov/GOES/floater.php?stormid=AL132023 https://rammb-data.cira.colostate.edu/tc_realtime/storm.asp?storm_identifier=al132023 Carib view: https://www.star.nesdis.noaa.gov/GOES/sector_band.php?sat=G16§or=car&band=13&length=24 By tomorrow it will be on the U.S. East Coast satellite view on their website: https://www.star.nesdis.noaa.gov/GOES/sector_band.php?sat=G16§or=eus&band=13&length=12 I like stable satellite views more than I do the floaters. Also, it's good to get some perspective at how large the storm is with a zoomed out view. I think the important part of the 5pm AST Monday discussion is this: "Although Lee is expected to weaken later in the week, it is expected to significantly increase in size and hazards will extend well away from the storm center by the end of the forecast period." Hurricane Lee Discussion Number 26 NWS National Hurricane Center Miami FL AL132023 500 PM AST Mon Sep 11 2023 Lee continues to exhibit a double eyewall structure as reported by the Air Force Hurricane Hunters and seen in recent microwave images. The inner eyewall is open on the south side, but the outer eyewall is completely closed and has contracted slightly from the earlier NOAA P-3 aircraft mission. The minimum pressure is the same as before, 948 mb, but the initial wind speed is nudged downward to 100 kt based on the aircraft data. The major hurricane has jogged a little to the left recently, and the initial motion is estimated to be 290/7 kt. The models are similar to the previous runs, and no big changes were made to the NHC track forecast. A continued slow motion between west-northwest and northwest is expected during the next couple of days as Lee remains steered by a mid-level high to its north-northeast. Beyond a couple of days, the ridge is expected to shift eastward as a mid- to upper-level trough amplifies over the eastern U.S. This pattern change should cause Lee to turn northward with an increase in forward speed. Lee is likely to pass near, but to the west of Bermuda, late Thursday and Friday and then be situated offshore of the mid-Atlantic states and New England late Friday and Saturday. Given the current concentric eyewall structure, it seems likely that Lee will fluctuate in strength in the short term. However, since the hurricane will remain in generally conducive conditions during the next couple of days, it could restrengthen if the eyewall cycle completes. Lee is likely to move over a cool SST wake left behind by Hurricanes Idalia and Franklin later this week, and cross over the north wall of the Gulf Stream by the end of the forecast period. The combination of cooler SSTs, an increase in shear, and dry air entrainment should cause a steady decay in strength late this week and over the weekend. The NHC intensity forecast is an update of the previous one and near the middle of the guidance envelope. Although Lee is expected to weaken later in the week, it is expected to significantly increase in size and hazards will extend well away from the storm center by the end of the forecast period. KEY MESSAGES: 1. Dangerous surf and life-threatening rip currents will affect portions of the northern Leeward Islands, the Virgin Islands, Puerto Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, Bermuda, and most of the U.S East Coast through much of the week. 2. Lee could bring strong winds, rainfall, and high surf impacts to Bermuda later this week. Interests there should continue to monitor updates to the forecast of Lee during the next several days. 3. It remains too soon to know what level of additional impacts Lee might have along the Northeast U.S. coast and Atlantic Canada late this week and this weekend. However, wind and rainfall hazards will likely extend well away from the center as Lee grows in size. Users should continue to monitor updates to the forecast of Lee during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 11/2100Z 23.6N 64.2W 100 KT 115 MPH 12H 12/0600Z 24.0N 65.1W 105 KT 120 MPH 24H 12/1800Z 24.6N 66.1W 105 KT 120 MPH 36H 13/0600Z 25.3N 66.9W 100 KT 115 MPH 48H 13/1800Z 26.5N 67.5W 100 KT 115 MPH 60H 14/0600Z 28.3N 67.8W 95 KT 110 MPH 72H 14/1800Z 30.3N 67.9W 90 KT 105 MPH 96H 15/1800Z 35.4N 67.1W 80 KT 90 MPH 120H 16/1800Z 40.8N 67.0W 65 KT 75 MPH $$ Forecaster Cangialosi While the models could change, I think it's reasonable to say at this point that Lee is more likely than not going to make a landfall in either Atlantic Canada or the Northeast United States. As for Bermuda, it remains uncertain what impacts they will see. GFS: https://www.tropicaltidbits.com/analysis/models/?model=gfs®ion=eus&pkg=mslp_pcpn Euro: https://www.tropicaltidbits.com/analysis/models/?model=ecmwf®ion=eus&pkg=mslp_pcpn At the moment, the GFS and Euro are around Nova Scotia and New Brunswick, also being close to Maine. (being not too far from Cape Cod on the way by) But with the storm so large later on, it would have some impacts in other areas of the Northeast U.S. with that track if that happened. (beyond dangerous rip currents) But, it's too soon to know what the track will be, whether closer or further than what the models currently forecast. It could be even closer, with a direct landfall still possible. But people should be prepared: https://www.noaa.gov/hurricane-prep I hope people don't see Lee as a hurricane that will be weakening, so it's something they shouldn't care about. Larger storms generate more surge. Sandy was an example of that. It made landfall with 80 mph winds, an hour after it technically became post-tropical. It's wind field in the forecast advisories before landfall were: 15Z on Oct. 29, 2012: 34 KT.......420NE 330SE 400SW 270NW. 21Z on Oct. 29, 2012: 34 KT.......420NE 370SE 400SW 200NW. 34 knots is 39 mph, the tropical storm force wind field. The values in each quadrant are in nautical miles. Multiple by 1.15 to get statute miles. Wind field forecasts from the NHC only go out 3 days. Through three day's, Lee's forecast size is: FORECAST VALID 14/1800Z 30.3N 67.9W: 34 KT...230NE 210SE 180SW 190NW. I assume it will get even larger and we'll see that reflected in future advisories. We'll have to see. I think it's helpful to view the Simulated IR Satellite from the GFS model: https://www.tropicaltidbits.com/analysis/models/?model=gfs®ion=neus&pkg=ir&fh=115 Don't focus on its exact track, take a look at the size of the storm. That doesn't go out as far as the GFS apparently. You can view through 115 hours which is enough. Look at the extent of the storm across the Northeast. (though onshore winds would be where the highest surge would be when it come to that threat) I also think it's a good idea to look at the GFS and Euro Ensemble members. GFS: https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens®ion=eus&pkg=lowlocs Euro: https://www.tropicaltidbits.com/analysis/models/?model=eps®ion=eus&pkg=lowlocs Where you can see there is a lot of difference among the individual members. One thing that's pretty consistent, it does make landfall. It's just a question of where. So landfall does seem likely. But a Canada landfall would not mean no impact to the U.S. Recon continues: https://hurricanecity.com/recon/ The NOAA G-IV is getting sonde data into some of the models, like the GFS. I didn't realize I guess, but HDOB data from flight level data also gets in. I explain a little about how you can see when sonde data gets into the GFS here: http://tropicalatlantic.com/reconnaissance/#ncep_monitoring_system But since it includes all sonde data, from Air Force and NOAA P-3s, it's really hard to know how many from the G-IV has gotten into a run. But, the data is eventually and the plane will be out doing a lot of missions. The "hdob" section tells you about HDOBs that have gotten in. I assume that each line must be treated as an ob, with 20 lines per actual message, because for the 18Z GFS there was a count of 1245. (each line has flight level data every 30 seconds) But that sonde data, taking measurements on the way down after being dropped from the aircraft, is helpful to the models. Rather than guessing what the profile of the atmosphere is over the middle of nowhere in the Atlantic, you'll have actual data to put into the model. That helps for determining steering that will determine where the storm might go. |