Hurricane Don

[WxWatcher007]

Don has become the first hurricane of the 2023 Atlantic hurricane season.

Starting a thread for record keeping purposes. Can a mod move the Don related posts here? 

[Windspeed]

Not too shabby....

[GaWx]

  This is close to the most impressive looking cat 1 I can recall ever seeing. All 12Z trop models, which had it at cat 1 as of 18z, strengthen it to well into cat 2 (90-95 knts) as we head into tonight with a peak near DMAX/6Z. The NHC otoh has it weakening back to 60 knots at 6Z:

"Today's strengthening was the result of the storm passing over the warmer waters of the Gulf Stream, however it will move north of those warmer waters later this evening, and Don has likely peaked in intensity. Weakening should begin overnight, with a faster rate of weakening expected Sunday through Monday as Don moves over even colder waters and the vertical wind shear increases.

FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 40.1N 50.0W 65 KT 75 MPH

12H 23/0600Z 42.0N 49.6W 60 KT 70 MPH

24H 23/1800Z 44.5N 47.6W 50 KT 60 MPH

36H 24/0600Z 46.4N 44.5W 40 KT 45 MPH...POST-TROPICAL

48H 24/1800Z 47.7N 40.4W 30 KT 35 MPH...POST-TROP/REMNT LOW

60H 25/0600Z...DISSIPATED $$ Forecaster Brown"

[Windspeed]

No surprise to see Don looking heathier as the core is now riding over an area of ≥26°C SSTs.

[WxWatcher007]

 

[olafminesaw]

A work of art this one.

[WxWatcher007]

 

[SolidIcewx]

3 hours ago, WxWatcher007 said:

 

 

[yoda]

BULLETIN
Hurricane Don Advisory Number  36
NWS National Hurricane Center Miami FL       AL052023
1100 PM AST Sat Jul 22 2023

...DON STILL A HURRICANE BUT BEGINNING TO MOVE NORTH-NORTHEASTWARD
OVER COOLER WATERS...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...41.4N 49.6W
ABOUT 405 MI...650 KM SSE OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NNE OR 15 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...988 MB...29.18 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Hurricane Don was located
near latitude 41.4 North, longitude 49.6 West. Don is moving toward
the north-northeast near 14 mph (22 km/h). A turn northeastward  is
expected tomorrow, with a northeastward to east-northeastward motion
expected to continue until the system dissipates Monday night or
early Tuesday.

Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts.  Steady weakening is expected to begin shortly, and Don is
forecast to become a post-tropical cyclone by Sunday night.

Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 90 miles
(150 km).

The estimated minimum central pressure is 988 mb (29.18 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Papin

[yoda]

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM

Hurricane Don Discussion Number  36
NWS National Hurricane Center Miami FL       AL052023
1100 PM AST Sat Jul 22 2023

Don's structure on satellite imagery remains well organized for a 
tropical cyclone at such a high latitude in late July. A small but 
distinct eye has persisted, surrounded by moderately cold cloud 
tops. However, the coldest cloud tops are beginning to erode on the 
north edge of the eye, and the upper-level outflow has also become 
more restricted in that direction. These factors likely indicate 
that Don is starting to feel the effects of nearby cooler waters 
and increased vertical wind shear that will ultimately lead to a 
swift decline in intensity. For now, the latest subjective Dvorak 
estimates were T4.0 (65 kt) from both SAB and TAFB, and objective 
intensity estimates currently range from 53 kt to 69 kt. It is 
worth noting that UW-CIMSS ADT estimates have been much lower, 
apparently due to that objective technique failing to pick up on the 
eye pattern seen on satellite today. Discounting that outlier, a 
blend of other subjective and objective data supports an initial 
intensity of 65 kt for this advisory. Don's wind radii have also 
been adjusted some due to a helpful ASCAT-B pass at 2348 UTC.

Now that Don is moving north of a warm eddy in the Gulf Stream, the 
cyclone should soon encounter much colder sea-surface temperatures 
along its track. Thus, steady weakening is expected to begin 
shortly. As Don quickly loses its deep convection, the cyclone is 
forecast to become post-tropical in 36 h, with the circulation 
expected to open up into a trough axis after 48 h. This forecast is 
in good agreement with the global and hurricane-regional model 
guidance.

Don is now moving to the north-northeast a bit faster than before at 
015/12 kt. A continued turn to the northeast with a bit more 
acceleration is anticipated overnight into tomorrow as Don is 
embedded within southwesterly steering flow between a subtropical 
ridge to its southeast and a deep-layer trough located over eastern 
Canada. This pattern should persist until Don dissipates, with the 
system continuing to recurve eastward over the next 48 h. The track 
guidance has shifted a bit faster than the prior cycle but still 
remains along a similar trajectory. Thus the NHC track forecast 
remains very close to the prior track, but just a little faster.


FORECAST POSITIONS AND MAX WINDS

INIT  23/0300Z 41.4N  49.6W   65 KT  75 MPH
 12H  23/1200Z 43.3N  48.5W   55 KT  65 MPH
 24H  24/0000Z 45.5N  46.0W   45 KT  50 MPH
 36H  24/1200Z 47.2N  42.1W   35 KT  40 MPH...POST-TROPICAL
 48H  25/0000Z 48.1N  37.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  25/1200Z...DISSIPATED

$$
Forecaster Papin

[NorthHillsWx]

Last advisory has been issued. Also included in the discussion:

“Don has been a very long-lasting tropical cyclone (including
subtropical stages) for the month of July.  Preliminary data
indicate that the storm is the 5th longest-lasting system on record
for the month, just behind Emily of 2005.”