Major Hurricane Florence: STORM MODE THREAD

[MikeB_01]

Recon pressure up to 958 on last pass

[MikeB_01]

5 minutes ago, MikeB_01 said:

Recon pressure up to 958 on last pass

I stand corrected. There was a 957.2 in there

[zinski1990]

957 mb? wow weaker wonder if it drops back

[MikeB_01]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 13th day of the month at 3:13Z
Agency: United States Air Force 
Aircraft: Lockheed WC-130J Hercules with reg. number AF98-5308 
Storm Number & Year: 06 in 2018
Storm Name: Florence (flight in the North Atlantic basin)
Mission Number: 13
Observation Number: 10 ( See all messages of this type for this mission. )

A. Time of Center Fix: 13th day of the month at 2:53:00Z
B. Center Fix Coordinates: 31.96N 73.72W
B. Center Fix Location: 250 statute miles (403 km) to the SSE (155°) from Cape Hatteras, NC, USA.
C. Minimum Height at Standard Level: 2,743m (8,999ft) at 700mb
D. Minimum Sea Level Pressure: 959mb (28.32 inHg) - Extrapolated
E. Dropsonde Surface Wind at Center (Undecoded): NA
F. Eye Character: Open in the southeast
G. Eye Shape & Diameter: Circular with a diameter of 36 nautical miles (41 statute miles)
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 85kts (97.8mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 22 nautical miles (25 statute miles) to the NE (51°) of center fix at 2:46:30Z
J. Maximum Flight Level Wind Inbound: From 128° at 100kts (From the SE at 115.1mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 27 nautical miles (31 statute miles) to the NE (51°) of center fix at 2:45:00Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 72kts (82.9mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 21 nautical miles (24 statute miles) to the SW (229°) of center fix at 2:59:30Z
N. Maximum Flight Level Wind Outbound: From 316° at 73kts (From the NW at 84.0mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 29 nautical miles (33 statute miles) to the SW (229°) of center fix at 3:02:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 12°C (54°F) at a pressure alt. of 3,045m (9,990ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 17°C (63°F) at a pressure alt. of 3,044m (9,987ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 6°C (43°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: 0.02 nautical miles
T. Meteorological Accuracy: 2 nautical miles

Remarks Section - Remarks That Were Decoded...
 

Maximum Flight Level Wind: 100kts (~ 115.1mph) which was observed 27 nautical miles (31 statute miles) to the NE (51°) from the flight level center at 2:45:00Z
Sea Level Pressure Extrapolation From: 700mb

Remarks Section - Additional Remarks...
 

CENTER DROPSONDE TERMINATED 14M OFF SFC REPORTING WINDS 165 DEGREES AT 05 KTS

[csnavywx]

That high level shear is really showing up well on IR and the 250mb charts now. However, as the NHC discussion stated, it abates between 06 to 12Z tomorrow. Until then, expect more weakening as that shear is now able to impinge directly on the core.

[hazwoper]

The SW portion of the eyeball is finally appearing to close with colder cloud tops completely filling in now.  Let’s see what happens over the next few hours

[jojo762]

While Florence continues to struggle and look less than ideal with a myriad of less-than-perfect conditions contributing, the core/eyewall looks about as good now as it has for several hours with intense DMC wrapping around the entire eye (unsure if it’s still an eye or not).

[ncskywarn]

GFS at 36 almost identical to 18Z. At 66 just a little East of 18Z.

[Radtechwxman]

23 minutes ago, csnavywx said:

That high level shear is really showing up well on IR and the 250mb charts now. However, as the NHC discussion stated, it abates between 06 to 12Z tomorrow. Until then, expect more weakening as that shear is now able to impinge directly on the core.

Core isn't as exposed as it was earlier. Deeper convection blowing up around center and to the south. Might see it level off. But the intensity with this has been anything but predictable so who knows

[Chinook]

26 minutes ago, MikeB_01 said:

 

Maximum Flight Level Wind: 100kts (~ 115.1mph) which was observed 27 nautical miles (31 statute miles) to the NE (51°) from the flight level center at 2:45:00Z
Sea Level Pressure Extrapolation From: 700mb

Remarks Section - Additional Remarks...
 

CENTER DROPSONDE TERMINATED 14M OFF SFC REPORTING WINDS 165 DEGREES AT 05 KTS

Based on some of this information, surface winds may max out at 85 kt - 95 kt (cat 2) in the more substantial part of the eyewall. Flight level winds are above 96 kt (cat 3) in a few varied spots northeast of the eye. A pressure of 959 mb is still quite substantial, supporting a general cat 2-cat 3. The Saffir-Simpson scale is no longer based on pressure, though.

[Windspeed]

The easterly outflow channel moving away from the western side of the cyclone looks really impressive right now. Keep in mind, Florence has a large circulation and any intense convection may not translate to a rapid increase in vortex wind speeds. Having said that, the higher OHC, what looks like increasing upper-level environmental support and slow progression across the Gulf Stream, Florence may go to town tomorrow. I really like the look of the CDO at the moment. It has the look of a cyclone about to intensify versus one that is degrading and falling apart. Fascinating stuff at such a high latitude.

 

 

 

[SnowGoose69]

Even if the winds don’t catch up you still would prefer to not have a hurricane in an increasing phase as it makes landfall because it’s been shown there is a greater tendency for winds to effectively mix down in those cases.  We’ve seen weakening 125mph storms produce surprisingly minimal wind damage at landfall while a strengthening 95mph system produces gusts of 110-120mph

[Amped]

11 minutes ago, Windspeed said:

The easterly outflow channel moving away from the western side of the cyclone looks really impressive right now. Keep in mind, Florence has a large circulation and any intense convection may not translate to a rapid increase in vortex wind speeds. Having said that, the higher OHC, what looks like increasing upper-level environmental support and slow progression across the Gulf Stream, Florence may go to town tomorrow. I really like the look of the CDO at the moment. It has the look of a cyclone about to intensify versus one that is degrading and falling apart. Fascinating stuff at such a high latitude.

 

 

 

Bands are wrapping around instead of peeling away now.  Big improvement.   It clearly has a concentric eyewalls though, observed by recon and you can kind of make them out on IR

[jojo762]

Honestly the core looks significantly more symmetric within the last hour on IR. I expect it to give one more go at at least some reintensification tonight into tomorrow morning. Fairly low expectations for how much it is able to intensify given the overall antecedent conditions that have been discussed today... likewise, there will be a “prime time” window later tonight at some point when shear relaxes, but the system is far too large and far too complex (see concentric eyewalls)  for any overly impressive reintensification to occur imo. 

[BuffaloWeather]

https://www.tropicaltidbits.com/sat/satlooper.php?region=06L&product=ir

[BuffaloWeather]

3 minutes ago, jojo762 said:

Honestly the core looks significantly more symmetric within the last hour on IR. I expect it to give one more go at at least some reintensification tonight into tomorrow morning. Fairly low expectations for how much it is able to intensify given the overall antecedent conditions that have been discussed today... likewise, there will be a “prime time” window later tonight at some point when shear relaxes, but the system is far too large and far too complex for any overly impressive reintensification to occur imo. 

Big flare up of convection on the SW portion of the eyewall. Will be interesting to watch the next few hours to see if that wraps itself around the eastern portions of the eyewall.

[KoalaBeer]

14 minutes ago, SnowGoose69 said:

Even if the winds don’t catch up you still would prefer to not have a hurricane in an increasing phase as it makes landfall because it’s been shown there is a greater tendency for winds to effectively mix down in those cases.  We’ve seen weakening 125mph storms produce surprisingly minimal wind damage at landfall while a strengthening 95mph system produces gusts of 110-120mph

This right here! It's amazing to me how much more efficient these storms are at mixing winds to the surface in a strengthening phase. Looking better on satellite for sure and now starting to come into view of long range radar.

[Radtechwxman]

Curious to see an updated microwave image. To see if an EWRC is occurring with those concentric eyewalls present

[hazwoper]

3 minutes ago, StormChaser4Life said:

Curious to see an updated microwave image. To see if an EWRC is occurring with those concentric eyewalls present

It’s gonna take a bit.  The CIMSS microwave is lagging the GOES IR by about 2 hrs it appears

[Radtechwxman]

3 minutes ago, hazwoper said:

It’s gonna take a bit.  The CIMSS microwave is lagging the GOES IR by about 2 hrs it appears

Is that normal or is there issues?

[hazwoper]

1 minute ago, StormChaser4Life said:

Is that normal or is there issues?

I think it’s normal 

[hlcater]

13 minutes ago, StormChaser4Life said:

Curious to see an updated microwave image. To see if an EWRC is occurring with those concentric eyewalls present

Given the large size and Levi’s most recent video, it probably won’t consolidate a single true eyewall anymore. It’s essentially a bariatric hurricane. Too large and overweight to the point it’s causing detrimental effects to the health of the storm.

[40/70 Benchmark]

3 minutes ago, hlcater said:

Given the large size and Levi’s most recent video, it probably won’t consolidate a single true eyewall anymore. It’s essentially a bariatric hurricane. Too large and overweight to the point it’s causing detrimental effects to the health of the storm.

Agree....I'd be surprised at any significant intensification.

[bdgwx]

It looks like the core is starting to come into range of KMHX. The angle of approach is putting that right flank parallel to the beam. I'm getting 80 kt winds at 25,000 ft in that region. Not that we didn't already know, but making some guesstimates based on what little is in range I'll say hurricane force winds extend 55nm from the center on the right flank and 30nm from the center on the left flank.

[Radtechwxman]

Yea the size will hinder winds coming up. If the pressure drops the energy will be spread out over such a large area

[Windspeed]

Given the large size and Levi’s most recent video, it probably won’t consolidate a single true eyewall anymore. It’s essentially a bariatric hurricane. Too large and overweight to the point it’s causing detrimental effects to the health of the storm.

I agree with Levi. The circulation of Florence is large. However, as some other posters have pointed out, you don't help the situation if favorable environmental conditions improve. You want this hurricane to fall apart. If the hurricane gains convection and reorganization of the core, you increase the odds that a devastating surge event occurs at this point. Nobody is expecting a Hugo here, at least with regards to wind speeds. But you already have destructive surge incoming due to Florence's large circulation. You want Florence to fall apart as much as possible to mitigate it. You do not want Florence to recover and exacerbate that perpendicular surge from onshore flow up to landfall.

 

 

[SENC]

just starting to come with-in range.. of KLTX.. (KILM)?  

[David Reimer]

Inner core definitely looks better on IR than it did two hours ago. -79C towers on the west/southwest eyewall. As others have stated, we're unlikely to see a significant wind increase based on the expansive wind field along with the observed behavior fo the system today. Recon is going through the eye now and the pressures don't look to have changed. 

[HillsdaleMIWeather]

Pressure is actually down compared to last pass

[Dunkman]

Looking at recon observations so far there is no real eyewall left at all. It's just a huge area of category 1 winds.