Tropical Storm Bret

[Ed, snow and hurricane fan]

If it survives the shear and dry air in the Caribbean, and doesn't recurve, Bret would head W into Central America/Mexico.  GFS and Euro ensembles both support that.  The NHC forecast of a weakening system headed for its death in Hispaniola seems likely, Bret reopening into a wave and its remnants into Central America also seems reasonable. 

[Floydbuster]

9 minutes ago, WxWatcher007 said:

I really am starting to think the MDR being open like this may be an early signal of a more active season. It’s not just that much of the basin is historically warm…the TUTT is displaced northward and with this early wave train we are seeing no issues with stability and SAL like past years. 

To get one TC is historic for this time of year, the guidance is trending toward multiple TC genesis opportunities in the next 10-14 days. 

Unless it's a weird El Nino plus major positive AMO type thing to where it's gonna turn off suddenly in September. 

[WxWatcher007]

Despite the slightly warming cloud tops recently, Bret has continued to organize nicely this evening. We have a CDO and periodic hot towers attempting to rotate around the center. At 5pm, the NHC noted that the LLC was on the NW edge of the deeper convection. I don't have a microwave image, and that would certainly be telling. At any rate, it's looking dramatically better than it did 24 hours ago.  

[MJO812]

[WxWatcher007]

No (edit: current) intensity change at 11pm.

[WxWatcher007]

A slight pullback on the intensity forecast, but still noting high uncertainty. Development of a robust inner core will be critical for long term survival.  

Tropical Storm Bret Discussion Number   3
NWS National Hurricane Center Miami FL       AL032023
1100 PM AST Mon Jun 19 2023

This evening, Bret's structure on satellite has evolved from a 
curved banding pattern to a growing central dense overcast near 
the estimated center. The exact location of the center is tricky to 
pinpoint though, most likely positioned just west of the deepest 
central convection. Dvorak estimates from TAFB and SAB were both 
T2.5/35-kt at 00 UTC, 37-kt from UW-CIMSS, and unfortunately there 
have not been any helpful microwave or scatterometer passes this 
evening. The initial intensity is being held at 35 kt for this 
advisory in agreement with the majority of the available data.

The initial motion appears to be just north of due west at 275/16 
kt. A deep-layer ridge that is currently positioned overhead of Bret 
will initially follow along with the cyclone, maintaining a west or 
north of due west heading for the next 48-72 hours. As the system 
approaches the Lesser Antilles later this week, a mid- to 
upper-level trough is forecast to amplify somewhat, with the 
vertical depth of Bret likely to influence its future track. Once 
again there is a large spread in both along and cross track model 
predictions, with the ECMWF on the south and west end, and the GFS 
and some of the strongest hurricane regional models (HWRF, HAFS-A) 
on the north and east end. The consensus aids have shifted ever so 
slightly south and west from the previous forecast cycle, and the 
NHC track will follow suit, especially beyond 60-h. However, there 
continues to be larger than normal uncertainty in the track forecast 
given the large spread of the guidance suite.

In the short-term, environmental conditions remain quite favorable 
for additional intensification, with shear remaining under 10-kt, 
and ample mid-level moisture and anomalously warm SSTs maintaining a 
favorable thermodynamic environment. Thus, steady intensification 
seems likely for the next day or so. However, between 36-60 h, 
mid-level moisture begins to markedly decrease along Bret's forecast 
track, and both the GFS and ECMWF suggest mid-level northwesterly 
shear may begin to undercut the more favorable upper-level 
easterlies. This is where the intensity forecast becomes tricky, 
since a more vertically coherent system could be more resilient 
against these less favorable conditions versus one that remains less 
aligned and more susceptible to dry air intrusion. The intensity 
guidance also diverges over this time frame, with some of the 
regional hurricane guidance showing continued intensification, 
compared to leveling off from the global model guidance. The latest 
NHC forecast is a bit more conservative at this time frame, but 
still shows a peak intensity at hurricane intensity between 48-60 h. 
Thereafter, even drier air and additional shear is likely to begin a 
weakening trend, and the latest NHC intensity forecast shows a bit 
more weakening than the previous cycle. 


KEY MESSAGES:

1. Bret is forecast to initially strengthen and then move across 
the Lesser Antilles near hurricane intensity on Thursday and 
Friday, bringing a risk of flooding from heavy rainfall, strong 
winds, and dangerous storm surge and waves.

2. Given the larger than usual uncertainty in the track forecast,
it is too early to specify the location and magnitude of where
these hazards could occur. However, everyone in the Lesser
Antilles, Puerto Rico, and the Virgin Islands should closely monitor
updates to the forecast for Bret and have their hurricane
plan in place.


FORECAST POSITIONS AND MAX WINDS

INIT  20/0300Z 11.4N  43.5W   35 KT  40 MPH
 12H  20/1200Z 11.8N  45.8W   45 KT  50 MPH
 24H  21/0000Z 12.3N  48.7W   55 KT  65 MPH
 36H  21/1200Z 12.8N  51.4W   60 KT  70 MPH
 48H  22/0000Z 13.3N  53.9W   65 KT  75 MPH
 60H  22/1200Z 13.8N  56.7W   65 KT  75 MPH
 72H  23/0000Z 14.3N  59.4W   60 KT  70 MPH
 96H  24/0000Z 15.0N  64.5W   55 KT  65 MPH
120H  25/0000Z 16.5N  69.5W   50 KT  60 MPH

$$
Forecaster Papin

[Floydbuster]

It's funny that Bret looks great and is over-performing, and yet the long term prospects seem to have dwindled tonight. I've seen it happen before. In 2015, Hurricane Danny went from a Cat 3 east of the Lesser Antilles to a dissolved wave in the Eastern Caribbean. Even still, I'm surprised how bullish everyone seems about Bret's demise.

[WxWatcher007]

GFS op moved toward the Caribbean graveyard route. I’m really just in wait and see mode. 

[LakeNormanStormin]

Amateur opinion here. 2023 dynamics can't be accurately modeled. This storm will not be a victim of the graveyard.

[Kevin Reilly]

6 hours ago, WxWatcher007 said:

GFS op moved toward the Caribbean graveyard route. I’m really just in wait and see mode. 

It's not surprising if we are truly heading into an El Nino set up because the area where Brett is heading is typically a shear shred zone during El Ninos.   Looks to me the last of the La Nina pattern in regard to hurricane development is still hanging on off the Coast of Africa along with abnormally warm waters has the MDR season starting early.  

[Superstorm93]

7 hours ago, LakeNormanStormin said:

Amateur opinion here. 2023 dynamics can't be accurately modeled. This storm will not be a victim of the graveyard.

Taking a good deal of mid-level shear, which is also helping to entrain dry air from the west into the circulation. The odds have increased substantially that this will indeed be a victim of the graveyard. 

 

[WxWatcher007]

Didn’t expect the presentation this morning based on how it looked last night.

[Kevin Reilly]

27 minutes ago, Superstorm93 said:

Taking a good deal of mid-level shear, which is also helping to entrain dry air from the west into the circulation. The odds have increased substantially that this will indeed be a victim of the graveyard. 

 

Perfect illustration this is exactly it!!  

[WxWatcher007]

This was when I went to sleep lol. 

 

[MANDA]

Naked swirl alert!

[yoda]

 

 

[WxWatcher007]

16 minutes ago, yoda said:

 

 

Not so much now with an exposed center.

[WxWatcher007]

Nice convective burst right over the center in recent hours. Needs to hold for meaningful organization and eventual intensification.

[WxWatcher007]

 

[WxWatcher007]

Bret is trying to organize again despite the influence of mid level shear. We’ll see if that trend continues enough to develop an inner core.

[WxWatcher007]

Recon doing its thing right now. 

[WxWatcher007]

First VDM 

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 21st day of the month at 17:37Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5305 
Storm Name: Bret
Storm Number & Year: 03 in 2023 (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 06 ( See all messages of this type for this mission. )

A. Time of Center Fix: 21st day of the month at 16:55:20Z
B. Center Fix Coordinates: 13.21N 53.12W
B. Center Fix Location: 436 statute miles (702 km) to the E (89°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: 1,436m (4,711ft) at 850mb
D. Minimum Sea Level Pressure: 1001mb (29.56 inHg)
E. Dropsonde Surface Wind at Center: From 200° at 2kts (From the SSW at 2mph)
F. Eye Character: Not Available
G. Eye Shape: Not Available
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 53kts (61.0mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 13 nautical miles (15 statute miles) to the NNW (335°) of center fix at 16:51:00Z
J. Maximum Flight Level Wind Inbound: From 79° at 59kts (From between the ENE and E at 67.9mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 68 nautical miles (78 statute miles) to the NW (322°) of center fix at 16:31:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 36kts (41.4mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 7 nautical miles to the SSE (155°) of center fix at 16:58:00Z
N. Maximum Flight Level Wind Outbound: From 197° at 42kts (From the SSW at 48.3mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 37 nautical miles (43 statute miles) to the SE (137°) of center fix at 17:08:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 17°C (63°F) at a pressure alt. of 1,525m (5,003ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 1,525m (5,003ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 15°C (59°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Levels (surface & flight level centers within 5nm of each other): Surface and 850mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 3 nautical miles

Remarks Section:
 

Maximum Flight Level Wind: 59kts (~ 67.9mph) which was observed 68 nautical miles (78 statute miles) to the NW (322°) from the flight level center at 16:31:30Z

[WxWatcher007]

High rain rate with the observations, but FL winds of 59kts and a few 55kt SFMR readings on the NE to SW pass. No real pressure fall though on the center pass.

[WxWatcher007]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 21st day of the month at 18:47Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5305 
Storm Name: Bret
Storm Number & Year: 03 in 2023 (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 12 ( See all messages of this type for this mission. )

A. Time of Center Fix: 21st day of the month at 18:25:10Z
B. Center Fix Coordinates: 13.25N 53.43W
B. Center Fix Location: 416 statute miles (669 km) to the E (89°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: 1,441m (4,728ft) at 850mb
D. Minimum Sea Level Pressure: 1001mb (29.56 inHg)
E. Dropsonde Surface Wind at Center: From 180° at 11kts (From the S at 13mph)
F. Eye Character: Not Available
G. Eye Shape: Not Available
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 55kts (63.3mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 21 nautical miles (24 statute miles) to the NE (40°) of center fix at 18:11:30Z
J. Maximum Flight Level Wind Inbound: From 117° at 59kts (From the ESE at 67.9mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 25 nautical miles (29 statute miles) to the NE (39°) of center fix at 18:10:30Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 31kts (35.7mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 18 nautical miles (21 statute miles) to the SW (217°) of center fix at 18:33:00Z
N. Maximum Flight Level Wind Outbound: From 289° at 26kts (From the WNW at 29.9mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 10 nautical miles (12 statute miles) to the SSW (210°) of center fix at 18:30:30Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 16°C (61°F) at a pressure alt. of 1,524m (5,000ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 21°C (70°F) at a pressure alt. of 1,522m (4,993ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 18°C (64°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
S. Fix Levels (surface & flight level centers within 5nm of each other): Surface and 850mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 2 nautical miles

Remarks Section:
 

Maximum Flight Level Wind: 59kts (~ 67.9mph) which was observed 25 nautical miles (29 statute miles) to the NE (39°) from the flight level center at 18:10:30Z

[NorthHillsWx]

Seems like this flight more or less confirmed the NHC estimates. Maybe they bump it to 55kt but everything seems to match earlier intensity estimates

[tiger_deF]

Bret is looking pretty good right now. Outflow is limited, but it this convective burst is the coldest and longest-lasting for the past few days. A broad feeder band has been developing as well. 

[WxWatcher007]

Even better look per recon. Just saw a big extrapolated pressure drop, waiting for the dropsonde.

[WxWatcher007]

Perhaps some over performance tonight by Bret? Numerous 60+ kt unflagged SFMR in the latest obs.

Should be noted that FL winds don’t mirror hurricane force in this specific set of obs. 

[WxWatcher007]

VDM suggests that this is very near if not already at hurricane status. 

996mb with peak FL and SFMR obs over 64kts. 

Perhaps most notable is the first appearance of a partial eyewall.

[WxWatcher007]

Shame we couldn’t get another pass. This one is close and recon has been great at observing the real-time structural changes, that could all be undercut by shear before the next flight.