TC Bertha

[senorpepr]

Respectfully, wxman, I'm not sure it's weakening that much. The coverage of -60C convection is still there and the only real warming has been the loss of whatever few -70C convective bursts there were. Also, the eye has cleared out a bit despite the weakening convection.

That would still be enough to drop a Dvorak estimate by T0.5...

[CrazyC83]

The storm hasn't weakened; the pressure was too low at the previous advisory. This has been corrected to 952 mbar in the ATCF file.

For what it's worth, Bertha officially underwent RI by dropping more than 42 mbar in 24 hours.

That seems to make more sense. I think it was more likely around 958mb at the 5 pm advisory.

[NFLDART]

Hopefully a FISH

[Derek Ortt]

However, a clearer eye raises the ODT number. Thus, if the eye clears and the cloud tops warm, the difference between the eyewall cloud top temp and the eye temp remains the same

[NDG]

wxman....just looking at the WV I see the tutt getting ready to leave out of the pic...I also see some clouds coming down directly to bertha's north. To me that looks like the eastern fringe of the Ridge...What do you think?

I see an upper low SSE-S of Bermuda near 29N/64W moving westward and a jet digging south to the east of this low. Outflow on Bertha's north side is streaming NE up the TUTT. Could be the TUTT has helped to ventilate Bertha today. But will the high build in front of Bertha fast enough to prevent recurvature tonight/tomorrow? I think the NHC will make an eastward track adjustment at 10.

True...I just seen that ULL as well. I guess by tomorrow we should really have a better handle on where she will go...I think it is possible this goes out tonight or tomorrow. I wonder what kind of monkey wrench that ULL will have..If any.

Like Deltadog said all I see is UL northerly winds approaching Bertha, I just can't see Bertha moving NW that much longer before getting influenced by the ridge over Bermuda, not unless she goes ahead in making the whole recurveture soon. In the short term she will have to slow down or start tracking once again WNW and then when the Bermuda ridge starts moving eastward she goes back to a NW and eventual Northerly track out to see.

[tolakram]

However, a clearer eye raises the ODT number. Thus, if the eye clears and the cloud tops warm, the difference between the eyewall cloud top temp and the eye temp remains the same

Ah, thanks for the explanation.

[gatorcane]

she definitely looks to be taking a more westerly turn over the past couple of hours. It's in response to a building ridge to the north that members have discussed.

http://www.ssd.noaa.gov/goes/east/tatl/loop-avn.html

[tolakram]

FYI here is an image when Bertha was near her strongest:



and here is the current image:



There has been a few spots of improvement in the last hour but generally the shape seems to be declining.

The water vapor loop shows this as well.

http://www.ssd.noaa.gov/goes/flt/t1/loop-wv.html

[Mecklenburg]

now at 105 KNOTS... NHC...

[kpost]

You can also see her western motion here still north of the forecast track

[Mecklenburg]

looks like this would be her peak intensity

[Chacor]

DURING THE AFTERNOON HOURS BETWEEN 1900 AND 2300 UTC...BOTH NHC AND
CIMSS OBJECTIVE T-NUMBERS WERE OSCILLATING AROUND 6.0 ON THE DVORAK
SCALE. NORMALLY THESE NUMBERS CORRESPOND TO AN INTENSITY OF 115
KNOTS. DURING THAT TIME THE EYE BECAME VERY DISTINCT AND WAS
SURROUNDED BY VERY COLD TOPS. BERTHA COULD HAVE REACHED A PEAK
INTENSITY A LITTLE BIT HIGHER THAN PREVIOUSLY ESTIMATED DURING THAT
PERIOD.

[wxman57]

looks like this would be her peak intensity

Advisory just out says Bertha likely reached 115 kts this afternoon and has been declining.

[cycloneye]

[gatorcane]

from the 11:00PM EST discussion:

BY DAYS 4 AND 5 THE STEERING CURRENTS
ARE FORECAST TO COLLAPSE AND BERTHA WILL PROBABLY MEANDER FOR A
LITTLE BIT.


I'd say that is pretty open-ended. NHC does not want to commit to recurve yet that is for sure.

meander for a little bit before moving which direction?

[MiamiensisWx]

DURING THE AFTERNOON HOURS BETWEEN 1900 AND 2300 UTC...BOTH NHC AND
CIMSS OBJECTIVE T-NUMBERS WERE OSCILLATING AROUND 6.0 ON THE DVORAK
SCALE. NORMALLY THESE NUMBERS CORRESPOND TO AN INTENSITY OF 115
KNOTS. DURING THAT TIME THE EYE BECAME VERY DISTINCT AND WAS
SURROUNDED BY VERY COLD TOPS. BERTHA COULD HAVE REACHED A PEAK
INTENSITY A LITTLE BIT HIGHER THAN PREVIOUSLY ESTIMATED DURING THAT
PERIOD.

That is remarkable, since it suggests Bertha may have been 110-115 kt, which corrobates to a borderline Cat 3/4 or marginal Cat 4 TC. This occurred on July 7.

Personally, 110 kt is a more realistic estimate, since I doubt the strongest 1-min winds may have reached the surface.

[Mecklenburg]

aw shucks... it could have been 115 kts...


i get the feeling somehow that this season will surpass 1999's 5 storms reaching category 4 status

[tolakram]

Moving toward the west, northwest? Golly, sure seems like north, northwest to me, plus the sat presentation has really weakened.

/shrug

Watch and learn is what I guess I'll have to do.

http://www.ssd.noaa.gov/goes/east/catl/loop-avn.html

[Category 5]

aw shucks... it could have been 115 kts...

Yeah I cried too.

[MiamiensisWx]

aw shucks... it could have been 115 kts...


i get the feeling somehow that this season will surpass 1999's 5 storms reaching category 4 status

If that is the intensity chosen posthumously (in the TCR), the cries of Bertha's relationship to "global warming" will arise.

A Category 4 hurricane on JULY 7 is unbelievable, folks; it has occurred in the past, but it is still unique. I'm slightly incredulous.