TC Bertha

[Ed Mahmoud]

Sorry for talking models on the wrong thread, but NAM is a North America area model, and I wouldn't put all that much faith in something near the edge of the domain, as it were, to use Seinfeldian terms. It is not master of this domain.

[HURAKAN]

[MiamiensisWx]

I could be incorrect, but it looks like the LLC has been moving very slightly north of due west over the last two hours. If this trend is substantive, Bertha may pass very slightly south of the next TPC forecast point.

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

We may see another slight westward adjustment of the NHC's five day cone at 11 a.m. EDT.

[HURAKAN]

If was thinking the same thing when I saw the visible loop of Bertha and plotted the Trop Points.

[Tampa Bay Hurricane]

"It would be quite anomalous for storm that formed this far east and at such a latitude to impact the US or carribean. "

Why would you say that? Bertha of 1996 hit NC as a CAT 2 HURRICANE and it was the furthest east a TC has formed (at that time) and it still hit land. Its ALL ABOUT THE SYNOPTICS!!!! You can talk climatology until you are blue in the face. If there is a ridge in place all the way to Bermuda with no impacts from an east coast trough, this thing WILL HIT LAND (depending on intensity). If the east coast trough weakens the ridge just west of Bermuda, this thing will recurve just west of Bermuda (again, depending on intensity). Its not that hard. Its all in the synoptics.

I think ronjon meant that most recurve, but said there are exceptions such as Bertha 1996, and seemed to agree
with jamies statement that this can break climatology. In fact ronjon's earlier statement "threat to the US?" seems to indicate that he as well as I see the possibility of a threat to the US.
I don't mean to put words in anyone's mouth, but that's how I interpreted it.

From my past experience here and on other boards, ronjon's analyses tend to be very good.

[MiamiensisWx]

I think ronjon meant that most recurve, but said there are exceptions such as Bertha 1996, and seemed to agree
with jamies statement that this can break climatology.

Climatology is simply past history. There isn't a mystical force that prevents something we have not seen from occurring. There are also several arguments that our climatological record is flawed, so some "unprecedented" events may not be so rare.

[Tampa Bay Hurricane]

I think ronjon meant that most recurve, but said there are exceptions such as Bertha 1996, and seemed to agree
with jamies statement that this can break climatology.

Climatology is simply past history. There isn't a mystical force that prevents something we have not seen from occurring.

I know the synoptics are more important than history. I see the synoptics of a strong ridge, leading me
to think of a possible threat to the US in 7-9 days or so. The only reason history was brought up was to add
perspective, but not to make a forecast, because making a forecast
based on history alone would mean dismissing a possible threat.
My personal feeling is that we will be watching this closely
over the SE US, Bahamas, Bermuda, etc. for the next 7 days at least.

[HURAKAN]

Bertha seems to be handling pretty good the "bad times."

[cycloneye]

Yes indeed!

[littlevince]

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

[jinftl]

good point...i wonder if there are is any significance in strength/placement of bermuda high, ridges off coast, etc. because it is early July that the models aren't taking into account....because of lack of comparable cape verde system data for early july.

I think ronjon meant that most recurve, but said there are exceptions such as Bertha 1996, and seemed to agree
with jamies statement that this can break climatology.

Climatology is simply past history. There isn't a mystical force that prevents something we have not seen from occurring. There are also several arguments that our climatological record is flawed, so some "unprecedented" events may not be so rare.

[Tampa Bay Hurricane]

This is going to be one of those cases where much will
depend on the strength of the ridge, and that ridge
looks strong, synoptically speaking. Throw climatology
out the window on this one.

['CaneFreak]

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

Surprised no one caught this but the center is now actually EAST of the convection as a little RELATIVE easterly shear is now taking over because of the cyclone's rather fast motion (21mph). Relative shear can be explained in this manner. Imagine you are on your bike on a day with no wind at all (calm). You are pedaling 21 mph and you still have wind blowing in your face. Why? Wind blows by you due to your relative motion against the calm wind. If the wind was blowing 10 mph in your face, then the wind relative to you would only be 11 mph. If the wind was blowing from behind you at 10 mph, then the wind relative to you would be 31 mph.

['CaneFreak]

From the above visible shot, my guesstimate is 17.1 North and 35.8 West. I may be tracking a Mid level vortex...I am not sure...will wait for the advisory that comes out in 15 mins or so...

[AJC3]

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

Surprised no one caught this but the center is now actually EAST of the convection as a little RELATIVE easterly shear is now taking over because of the cyclone's rather fast motion (21mph). Relative shear can be explained in this manner. Imagine you are on your bike on a day with no wind at all (calm). You are pedaling 21 mph and you still have wind blowing in your face. Why? Wind blows by you due to your relative motion against the calm wind. If the wind was blowing 10 mph in your face, then the wind relative to you would only be 11 mph. If the wind was blowing from behind you at 10 mph, then the wind relative to you would be 31 mph.

Actually you have this bass-ackwards. If you have wind blowing directly into your face at 10 MPH and you are pedalling at 21 MPH, then it actually enhances the wind shear relative to you (31 MPH). If you are pedalling at that same speed and you have a tailwind of 10 MPH, then the wind shear would be only 11 MPH.

If you are pedalling at 21 MPH and you have a tailwind of 21 MPH, then you actually have NO relative shear, not 42 MPH of relative shear.

['CaneFreak]

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

Surprised no one caught this but the center is now actually EAST of the convection as a little RELATIVE easterly shear is now taking over because of the cyclone's rather fast motion (21mph). Relative shear can be explained in this manner. Imagine you are on your bike on a day with no wind at all (calm). You are pedaling 21 mph and you still have wind blowing in your face. Why? Wind blows by you due to your relative motion against the calm wind. If the wind was blowing 10 mph in your face, then the wind relative to you would only be 11 mph. If the wind was blowing from behind you at 10 mph, then the wind relative to you would be 31 mph.

Actually you have this bass-ackwards. If you have wind blowing directly into your face at 10 MPH and you are pedalling at 21 MPH, then it actually enhances the wind shear relative to you (31 MPH). If you are pedalling at that same speed and you have a tailwind of 10 MPH, then the wind shear would be only 11 MPH.

If you are pedalling at 21 MPH and you have a tailwind of 21 MPH, then you actually have NO relative shear, not 42 MPH of relative shear.

I sure did...thanks for the correction....is that your analysis as well?

[Chacor]

Still no flights scheduled even though it will be past 40W soon, so it looks like they won't be sending planes out of Barbados.

NOUS42 KNHC 051400
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1000 AM EDT SAT 05 JULY 2008
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 06/1100Z TO 07/1100Z JULY 2008
TCPOD NUMBER.....08-035

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.
SMR

[MiamiensisWx]

Still no flights scheduled even though it will be past 40W soon, so it looks like they won't be sending planes out of Barbados.

NOUS42 KNHC 051400
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1000 AM EDT SAT 05 JULY 2008
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 06/1100Z TO 07/1100Z JULY 2008
TCPOD NUMBER.....08-035

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.
SMR

Do you believe fuel costs will limit the total number of missions to Bertha?

[lebron23]

i except track to shift right.................

[MiamiensisWx]

i except track to shift right.................

Please list your evidence. I certainly can't find any data that argues against another westward shift of the cone at 11 a.m. EDT. Thanks!