Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

Major Hurricane Irma


NJwx85

Recommended Posts

  • Replies 7.2k
  • Created
  • Last Reply
12 minutes ago, Hoosier said:

Nobody should be dismissing anything at this point, except maybe landfall in Texas or Bermuda.

Really can't stress enough to our guests and newer members that a wide range of options is still on the table.  Models will move around with each run.   

Anything outside the 3 day NHC cone is going to be very speculative.  The error on the 5 day cone is so large that it could be south of Cuba or missing the FL E. Coast.  We can take a hint from the lack of confidence from the best in the biz.

 

Link to comment
Share on other sites

4 minutes ago, Casualbrain said:

It's pretty darn close to MPI per charts

 

 

Historically, quasi-annular long track CV hurricanes get about as close as you can to the theoretical slope of MPI.  Georges did that BitD, also had annular characteristics and was a long tracker in a similar spot.

Link to comment
Share on other sites

Irma's intensification the past 12 hours is a good example of why the lowest central pressure observed is not a perfect sliding scale indicative of maximum sustained wind. Some hurricanes may form and intensify within a large surface trough with lower background pressure or not have interaction with a high millibar pressure surface ridge such as Irma. Even considering Irma's large eyewall and increasing wind field, it is within the southern periphery of high background surface pressure with a very intense pressure gradient. This is similar to other intense hurricanes in this region (Isabel being a great example).

 

As Irma continues WNW near or just north of the Greater Antilles and as it begins to position itself on the SW periphery of the ridge, background pressures will decrease. Additionally, Irma may continue to expand in size. As such, the pressure gradient will decrease around the vortex. It may very well end up having sub 920 mb pressures but weaker overall sustained winds. I am not saying this won't be a Cat 5 at some point in the Bahamas or north of the Antilles, I just think the overall sustained surface winds of 180 mph won't be observed in the Bahamas or near the SE CONUS. The size of the cyclone, lower background pressures/pressure gradient being the key factors here.

 

Obviously this post is semantics over peak intensity and is not in anyway deflection of how incredibly dangerous this hurricane will be in both winds and surge to what ever islands/landmass it will eventually encounter.

Link to comment
Share on other sites

2 minutes ago, Wentzadelphia said:

Hypothetically if Irma were to head into Cuba but then turn and steer into MIA, would she have enough time to redevelop into a 4-5? 

Yes, but it would depend on how much time is spent in Cuba.  Other than land interaction, there is not much on the broader scale to suggest weakening in that area.

Link to comment
Share on other sites

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 5th day of the month at 17:05Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF99-5309 
Storm Number & Year: 11 in 2017
Storm Name: Irma (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 21 ( See all messages of this type for this mission. )
A. Time of Center Fix: 5th day of the month at 16:38:10Z
B. Center Fix Coordinates: 16°53'N 58°53'W (16.8833N 58.8833W)
B. Center Fix Location: 197 statute miles (317 km) to the E (95°) from Saint John's, Antigua and Barbuda.
C. Minimum Height at Standard Level: 2,440m (8,005ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 160kts (~ 184.1mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 14 nautical miles (16 statute miles) to the NE (54°) of center fix
F. Maximum Flight Level Wind Inbound: From 138° at 151kts (From the SE at ~ 173.8mph)
G. Location of Maximum Flight Level Wind Inbound: 15 nautical miles (17 statute miles) to the NE (54°) of center fix
H. Minimum Sea Level Pressure: 926mb (27.35 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 9°C (48°F) at a pressure alt. of 3,066m (10,059ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 3,052m (10,013ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 13°C (55°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Closed 
M. Eye Shape & Diameter: Circular with a diameter of 24 nautical miles (28 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile

Remarks Section:
Maximum Flight Level Wind: 151kts (~ 173.8mph) which was observed 15 nautical miles (17 statute miles) to the NE (54°) from the flight level center at 16:33:00Z
Maximum Flight Level Wind Outbound: 148kts (~ 170.3mph) which was observed 16 nautical miles (18 statute miles) to the WNW (299°) from the flight level center at 16:44:30Z
Dropsonde Surface Wind at Center: From 180° at 4kts (From the S at 5mph)
Maximum Flight Level Temp: 19°C (66°F) which was observed 7 nautical miles to the ENE (62°) from the flight level center

Link to comment
Share on other sites

3 minutes ago, Wentzadelphia said:

Hypothetically if Irma were to head into Cuba but then turn and steer into MIA, would she have enough time to redevelop into a 4-5? 

Location of landfall and duration of time over Cuba would be key. Below is a link to Cuba's topography:

http://en-us.topographic-map.com/places/Cuba-7906713/

Link to comment
Share on other sites

:o

Quote

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 5th day of the month at 17:05Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF99-5309 
Storm Number & Year: 11 in 2017
Storm Name: Irma (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 21 ( See all messages of this type for this mission. )
A. Time of Center Fix: 5th day of the month at 16:38:10Z
B. Center Fix Coordinates: 16°53'N 58°53'W (16.8833N 58.8833W)
B. Center Fix Location: 197 statute miles (317 km) to the E (95°) from Saint John's, Antigua and Barbuda.
C. Minimum Height at Standard Level: 2,440m (8,005ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 160kts (~ 184.1mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 14 nautical miles (16 statute miles) to the NE (54°) of center fix
F. Maximum Flight Level Wind Inbound: From 138° at 151kts (From the SE at ~ 173.8mph)
G. Location of Maximum Flight Level Wind Inbound: 15 nautical miles (17 statute miles) to the NE (54°) of center fix
H. Minimum Sea Level Pressure: 926mb (27.35 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 9°C (48°F) at a pressure alt. of 3,066m (10,059ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 3,052m (10,013ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 13°C (55°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Closed 
M. Eye Shape & Diameter: Circular with a diameter of 24 nautical miles (28 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 700mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile

Remarks Section:
Maximum Flight Level Wind: 151kts (~ 173.8mph) which was observed 15 nautical miles (17 statute miles) to the NE (54°) from the flight level center at 16:33:00Z
Maximum Flight Level Wind Outbound: 148kts (~ 170.3mph) which was observed 16 nautical miles (18 statute miles) to the WNW (299°) from the flight level center at 16:44:30Z
Dropsonde Surface Wind at Center: From 180° at 4kts (From the S at 5mph)
Maximum Flight Level Temp: 19°C (66°F) which was observed 7 nautical miles to the ENE (62°) from the flight level center

 

Link to comment
Share on other sites

2 minutes ago, Deaglesnest said:

What are the chances this thing actually gets into the gulf now. Thank you for the link to the topography of Cuba btw, good stuff. 

Probably a 20%-30% chance if one goes by the 0z ECMWF ensembles; less than that if one goes by the 12z GEFS. The ECWMF will be initializing momentarily so we'll get more information in a little while.

Link to comment
Share on other sites

8 minutes ago, donsutherland1 said:

Location of landfall and duration of time over Cuba would be key. Below is a link to Cuba's topography:

http://en-us.topographic-map.com/places/Cuba-7906713/

Don, that is extremely helpful info for some of the questions people may have with disruption of the center if Irma were to have Cuba affect her. I could only find mountain ranges in the 500-700 foot range along the north central coasts, so I am not particularly sure how much it would definitely affect her, however toward Guantanamo you are looking at some ranges of 1700 ft or more potentially. Not sure many models have the track that far south however. Ultimately, as people have mentioned, makes a difference how long the eyewall were to spend over Cuba.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...