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Tropical Storm Henri


wxeyeNH
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6z GFS does keep a fairly steady motion into landfall. The distance between 6 hr positons doesn't decrease too much until Grace is inland. Still, that is at least 12 hours over decreasing thermodynamic support. I'm not sure how much baroclinic influence the binary interaction could give during that time for convective support to mix down 700-850 hPa level winds. Could surprise but obviously the biggest threat is flooding, which has been and should continue to be overstated.

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First VDM shows a 996mb pressure and elliptical eye shape

 

Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 21st day of the month at 11:40Z
Agency: National Oceanic and Atmospheric Administration (NOAA)
Aircraft: Lockheed WP-3D Orion (Reg. Num. N42RF)
Storm Name: Henri
Storm Number & Year: 08 in 2021 (flight in the North Atlantic basin)
Mission Number: 9
Observation Number: 07 ( See all messages of this type for this mission. )

A. Time of Center Fix: 21st day of the month at 10:06:37Z
B. Center Fix Coordinates: 33.26N 72.72W
B. Center Fix Location: 212 statute miles (340 km) to the SE (131°) from Cape Hatteras, NC, USA.
C. Minimum Height at Standard Level: 3,050m (10,007ft) at 700mb
D. Minimum Sea Level Pressure: 996mb (29.42 inHg)
E. Dropsonde Surface Wind at Center: From 230° at 31kts (From the SW at 36mph)
F. Eye Character: Not Available
G. Eye Shape: Elliptical (oval shaped)
G. Orientation of Major Axis in Elliptical Eye: 20° to 200° (NNE to SSW)
G. Length of Major Axis in Elliptical Eye: 20 nautical miles
G. Length of Minor Axis in Elliptical Eye: 10 nautical miles
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 45kts (51.8mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 4 nautical miles to the SSW (197°) of center fix at 10:05:33Z
J. Maximum Flight Level Wind Inbound: From 291° at 43kts (From the WNW at 49.5mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 15 nautical miles (17 statute miles) to the SSW (201°) of center fix at 10:02:56Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 57kts (65.6mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 7 nautical miles to the N (0°) of center fix at 10:08:19Z
N. Maximum Flight Level Wind Outbound: From 81° at 33kts (From the E at 38.0mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 10 nautical miles (12 statute miles) to the N (0°) of center fix at 10:09:04Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 10°C (50°F) at a pressure alt. of 3,061m (10,043ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 14°C (57°F) at a pressure alt. of 3,055m (10,023ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 8°C (46°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 Level: 700mb
T. Navigational Fix Accuracy: 0.01 nautical miles
T. Meteorological Accuracy: 2 nautical miles

Remarks Section:
 

Maximum Flight Level Wind: 43kts (~ 49.5mph) which was observed 15 nautical miles (17 statute miles) to the SSW (201°) from the flight level center at 10:02:56Z
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2 minutes ago, WinterWolf said:

No back tracking here bro…just conversation. Nothing wrong with that. We’ll see if he can turn the corner today and tonight. Maybe he does?  Would be very interesting if that does indeed happen. 

CT does not handle high wind events well so if we can keep inland gusts below 60mph we should be fine. I’m worried about these 3 trees that overhang the house on the East side so the gusts, wind direction, and obviously how saturated the ground is and gets…

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11 minutes ago, Damage In Tolland said:

You are the worst storm cancel poster on the board. Winter and summer 

 

9 minutes ago, Brian5671 said:

Amd you are the worst weenie out there hanging on til the last possible second….lol take a breath dude and do you really want 5+ days without power 

So what you guys are saying is that I should take both of what you all say and split the difference for an accurate forecast? :drunk:

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Here's the center sonde that confirmed the 993mb pressure.

 

Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)
Transmitted: 21st day of the month at 11:50Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5304
Storm Name: Henri
Storm Number: 08 (flight in the North Atlantic basin)
Mission Number: 10
Observation Number: 04 ( See all messages of this type for this mission. )

Part A...
 

Date: Near the closest hour of 11Z on the 21st day of the month
Highest Mandatory Level For Which Wind Was Reported: 700mb
Coordinates: 33.5N 72.6W
Location: 206 statute miles (332 km) to the SE (126°) from Cape Hatteras, NC, USA.
Marsden Square: 116 ( About )
 
Surface and Standard Isobaric Surfaces
Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed
1000mb -60m (-197 ft) This level does not exist in this area of the storm above the surface level.
993mb (29.33 inHg) Surface (Sea Level) 27.4°C (81.3°F) 25.6°C (78°F) 250° (from the WSW) 4 knots (5 mph)
925mb 629m (2,064 ft) 22.8°C (73.0°F) 22.5°C (72°F) 220° (from the SW) 10 knots (12 mph)
850mb 1,365m (4,478 ft) 19.4°C (66.9°F) 18.3°C (65°F) 255° (from the WSW) 13 knots (15 mph)
700mb 3,028m (9,934 ft) 14.0°C (57.2°F) About 9°C (48°F) 270° (from the W) 5 knots (6 mph)

Information About Radiosonde:
- Launch Time: 11:25Z
- About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction.

Remarks Section...
 
Dropsonde Location: Dropped in center.

Highest altitude where wind was reported:
- Location: 33.50N 72.56W
- Time: 11:25:20Z

Lowest altitude where wind was reported:
- Location: 33.51N 72.55W
- Time: 11:30:08Z

Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding):
- Wind Direction: 220° (from the SW)
- Wind Speed: 9 knots (10 mph)

Deep Layer Mean Wind (average wind over the depth of the sounding):
- Wind Direction: 245° (from the WSW)
- Wind Speed: 9 knots (10 mph)
- Depth of Sounding: From 697mb to 993mb

Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding:
- Lowest 150m: 155 gpm - 5 gpm (509 geo. feet - 16 geo. feet)
- Wind Direction: 220° (from the SW)
- Wind Speed: 9 knots (10 mph)

Sounding Software Version: AEV 30404
 

Part B: Data for Significant Levels...
 

Significant Temperature And Relative Humidity Levels
Level Air Temperature Dew Point
993mb (Surface) 27.4°C (81.3°F) 25.6°C (78°F)
850mb 19.4°C (66.9°F) 18.3°C (65°F)
766mb 17.6°C (63.7°F) About 12°C (54°F)
718mb 15.4°C (59.7°F) About 8°C (46°F)
703mb 14.0°C (57.2°F) 9.3°C (49°F)
697mb Unavailable
 
Significant Wind Levels
Level Wind Direction Wind Speed
993mb (Surface) 250° (from the WSW) 4 knots (5 mph)
977mb 220° (from the SW) 10 knots (12 mph)
945mb 210° (from the SSW) 10 knots (12 mph)
924mb 220° (from the SW) 10 knots (12 mph)
893mb 260° (from the W) 12 knots (14 mph)
870mb 245° (from the WSW) 12 knots (14 mph)
850mb 255° (from the WSW) 13 knots (15 mph)
776mb 260° (from the W) 10 knots (12 mph)
767mb 250° (from the WSW) 13 knots (15 mph)
755mb 275° (from the W) 11 knots (13 mph)
747mb 245° (from the WSW) 11 knots (13 mph)
735mb 245° (from the WSW) 10 knots (12 mph)
697mb 285° (from the WNW) 6 knots (7 mph)
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Just now, WxWatcher007 said:

Additional unflagged 60-63kt SFMR and 60-62kt FL wind data coming from recon mission 9. This is extremely close to being a hurricane. 

I mean it’s all just semantics anyway at this level.  I mean is anyone gonna notice the difference between a 70 mph high end T.S., and a 74 mph minimal cane?  Not a chance. 
 

But if he’s an 85 mph Cane, then that’s a different story.  Maybe today and tonight he makes a name for himself, and pulls it together on his final approach into SNE? 

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...Long Island into southern New England...
   Tropical system Henri -- forecast by the latest NHC updates to move
   onshore over Long Island during the day Sunday -- will be
   accompanied by widespread strong winds and heavy rainfall.  With
   little instability expected inland, thunderstorm activity in outer
   bands will likely be muted to some degree.  Still, a few stronger
   convective cells in bands within the northeast quadrant of the storm
   may prove capable of convectively enhanced wind gusts, and possibly
   a brief tornado or two, through the period.

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4 minutes ago, WinterWolf said:

I mean it’s all just semantics anyway at this level.  I mean is anyone gonna notice the difference between a 70 mph high end T.S., and a 74 mph minimal cane?  Not a chance. 
 

But if he’s an 85 mph Cane, then that’s a different story.  Maybe today and tonight he makes a name for himself, and pulls it together on his final approach into SNE? 

Looking at movement and temps probably another 12-14 hour window left to strengthen. 

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3 minutes ago, WinterWolf said:

I mean it’s all just semantics anyway at this level.  I mean is anyone gonna notice the difference between a 70 mph high end T.S., and a 74 mph minimal cane?  Not a chance. 
 

But if he’s an 85 mph Cane, then that’s a different story.  Maybe today and tonight he makes a name for himself, and pulls it together on his final approach into SNE? 

Whether or not it is designated right now is semantics, yes. But I'm trying to illustrate that this isn't as disorganized as some seem to think. Watching intensification can often be like watching paint dry, so it's really important for folks to not become a prisoner of the moment.

It is gradually organizing and it is not a leap at all to think that in 12 hours or so it would be an 80-85 mph hurricane, which is in line with the NHC forecast. Based on the data I see, I do not think Henri is underperforming the forecast so far. 

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2 minutes ago, HoarfrostHubb said:

I would not be telling people it would LF as a strong Cat 1.  

Landfall as a weak cat 1 might be a tall task. Strong cat 1 by the time it comes ashore seems very unlikely. We’d prob need very rapid intensification today up to like cat 2 if we wanted to entertain a landfall as a high end cat 1. 

The storm is going to weaken between peak intensity and landfall. 

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2 minutes ago, PowderBeard said:

Looking at movement and temps probably another 12-14 hour window left to strengthen. 

Yes, he’s got today to get it together.  We keep hearing how the shear was supposed dissipate, but it hasn’t dissipated quite enough to allow him to get it together.  Sometimes that’s how these go, they just can’t strengthen. Henri seems to be one of those.  At least so far…

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