TC Bertha

[fci]

Well folks I did call for the West movement about 2 days ago and it is finally here. I did not agree with the NHC about a WNW track. The ridge and heights north of Bertha are just too strong. You can see the pronounced ridge guiding Bertha through the WV loop:

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

Another thing I want to mention is that its rare for models about this time to show a west bend in the long-term. They almost always want to recurve or bend a system NW as it gets towards the CONUS. Part of the reason why is because of the more complex synoptic setup over the EC that typically exists.

I'm not buying a NC to New England area situation and I'm surprised anybody is considering how dead wrong the models have been for the life of Bertha. We can just monitor Bertha and anybody from the NE Leewards to Bermuda and the ENTIRE EC should be watching.

There is still plenty of time to watch Bertha. If she impacts the CONUS we are talking 8-10 days out. Alot can happen until now and then.

First off, we should always "be watching"

Having said that I totally buy that the ONLY area to watch is the NC to New England for Bertha simply due to history and experience in watching the Tropics for many years. I would be shocked if Bertha ever made it NEAR the CONUS. And even more shocked if it were of any appreciable strength if it did.

Yeah, I get surprised every once in a while but not too often.
Models or not, the odds are stacked way against Bertha affecting the CONUS short of possibly skirting the NC Outer Banks a hundred or more miles away. And I think that is a long shot too.

We will see; but I say NEVER expect the unexcepted but be ready just in case it happens......

[MiamiensisWx]

000
WTNT32 KNHC 052034
TCPAT2
BULLETIN
TROPICAL STORM BERTHA ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008
500 PM AST SAT JUL 05 2008

...BERTHA RACING WESTWARD ACROSS THE TROPICAL ATLANTIC...

AT 500 PM AST...2100Z...THE CENTER OF TROPICAL STORM BERTHA WAS
LOCATED NEAR LATITUDE 16.7 NORTH...LONGITUDE 39.3 WEST OR ABOUT 1015
MILES...1635 KM...WEST OF THE CAPE VERDE ISLANDS AND ABOUT 1570
MILES...2530 KM...EAST OF THE NORTHERN LEEWARD ISLANDS.

BERTHA IS MOVING TOWARD THE WEST NEAR 21 MPH...33 KM/HR...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE DURING THE NEXT COUPLE OF
DAYS. ON THIS TRACK BERTHA WILL REMAIN OVER THE TROPICAL ATLANTIC
WATERS FOR THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER
GUSTS. GRADUAL STRENGTHENING IS FORECAST OVER THE NEXT DAY OR TWO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB...29.53 INCHES.

REPEATING THE 500 PM AST POSITION...16.7 N...39.3 W. MOVEMENT
TOWARD...WEST NEAR 21 MPH. MAXIMUM SUSTAINED WINDS...50 MPH.
MINIMUM CENTRAL PRESSURE...1000 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER BROWN

[SouthFloridawx]

Let's just remember, the shift of the models and subsequently the track of Bertha can also change back to the north and east as it has changed to the west. Learning over the past few years, I have learned that Long Range forecasts for the upper levels aren't the best to go by. If this is a continued pattern over the next 3 days, then I would start to worry as Bertha moves closer to the Islands.

I am interested to see the track on days 4 and 5, but as many have said here... They would like to see them get rid of them, because of their inaccuracy.

That's correct, but I wasn't relying solely on the model guidance to formulate my argument for a slight west shift of the five day cone, especially within the short to medium term. The fact is that Bertha has exhibited a faster west bias within the short term, and it has also been weaker than originally progged for this time frame. However, I do concur that long range forecasts are very uncertain and complex, and it is always recommended to realize that tropical cyclones' eventual paths can even shift outside the cone.

I agree with your forecast, and I feel that it will be shifted farther to west due to the increase in forward speed. Thinking about it, this may also be an indication of how strong the ridge to the north is of the system.

A stronger ridge means a faster movement to the west... Correct me if I'm wrong.

Not using this in comparison, but I remember what happens when systems are under a strong ridge... They tend to intensify because they are ventilated much easier, the nature of the the High Above the system.

If I'm correct, this may result in a more intense system... as long as she stays south and in the warmer waters. That is key in this forecast.. The warm SST'S, strength of the ridge and the intensity and position of any shortwaves...

[MiamiensisWx]

First off, we should always "be watching"

Having said that I totally buy that the ONLY area to watch is the NC to New England for Bertha simply due to history and experience in watching the Tropics for many years. I would be shocked if Bertha ever made it NEAR the CONUS. And even more shocked if it were of any appreciable strength if it did.

Yeah, I get surprised every once in a while but not too often.
Models or not, the odds are stacked way against Bertha affecting the CONUS short of possibly skirting the NC Outer Banks a hundred or more miles away. And I think that is a long shot too.

We will see; but I say NEVER expect the unexcepted but be ready just in case it happens......

I definitely agree with the bolded portion, with the greatest emphasis on North Carolina.

[fci]

If the cone does touch the SE Bahamas. We are going to see the SE Fl Media go on hourly updates on Bertha.

If they start hourly updates when Bertha is >2400 miles away, they should be taken off the air. It wouldn't totally surprise me if the start hourly updates now.

It is Saturday of a holiday weekend and I think all you will get are teasers for the 11 PM news and top story coverage with a "wait and see" and " we will monitor it" message.

Don't look for hourly updates quite yet..

[canegrl04]

If the cone does touch the SE Bahamas. We are going to see the SE Fl Media go on hourly updates on Bertha.

If they start hourly updates when Bertha is >2400 miles away, they should be taken off the air. It wouldn't totally surprise me if the start hourly updates now.

Actually I'm alittle surprised the general media like Fox news Channel and CNN haven't started going bonkers yet over Bertha but I inagine by Monday they'll have a reporter doing live updates somewhere in S. Florida

[cycloneye]

[MiamiensisWx]

I agree with your forecast, and I feel that it will be shifted farther to west due to the increase in forward speed. Thinking about it, this may also be an indication of how strong the ridge to the north is of the system.

A stronger ridge means a faster movement to the west... Correct me if I'm wrong.

Not using this in comparison, but I remember what happens when systems are under a strong ridge... They tend to intensify because they are ventilated much easier, the nature of the the High Above the system.

If I'm correct, this may result in a more intense system... as long as she stays south and in the warmer waters. That is key in this forecast.. The warm SST'S, strength of the ridge and the intensity and position of any shortwaves...

The bolded portion is correct. A stronger low level ridge would often result in a faster forward movement.

[Category 5]

000
WTNT32 KNHC 052034
TCPAT2
BULLETIN
TROPICAL STORM BERTHA ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008
500 PM AST SAT JUL 05 2008

...BERTHA RACING WESTWARD ACROSS THE TROPICAL ATLANTIC...

AT 500 PM AST...2100Z...THE CENTER OF TROPICAL STORM BERTHA WAS
LOCATED NEAR LATITUDE 16.7 NORTH...LONGITUDE 39.3 WEST OR ABOUT 1015
MILES...1635 KM...WEST OF THE CAPE VERDE ISLANDS AND ABOUT 1570
MILES...2530 KM...EAST OF THE NORTHERN LEEWARD ISLANDS.

BERTHA IS MOVING TOWARD THE WEST NEAR 21 MPH...33 KM/HR...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE DURING THE NEXT COUPLE OF
DAYS. ON THIS TRACK BERTHA WILL REMAIN OVER THE TROPICAL ATLANTIC
WATERS FOR THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER
GUSTS. GRADUAL STRENGTHENING IS FORECAST OVER THE NEXT DAY OR TWO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB...29.53 INCHES.

REPEATING THE 500 PM AST POSITION...16.7 N...39.3 W. MOVEMENT
TOWARD...WEST NEAR 21 MPH. MAXIMUM SUSTAINED WINDS...50 MPH.
MINIMUM CENTRAL PRESSURE...1000 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER BROWN

[Weatherfreak000]

Why are we talking about South Florida? Climatologically that result would be one of the rarest storm landfalls in a while and nothing supports landfall there anyway.

Give that a 2% at best.

[Blown Away]

So it seems the only way for Bertha to make it to the Bahamas and SFL is as a shallow weak storm, if Bertha deepens strengthens it will allow her to bust through the ridge and go N.

[OuterBanker]

As usual, JB gives us a really different scenario. The Euro is rather crazy absorbing Bertha and turning it into the perfect storm off NE. He really doesn't think that will happen, but it is something that has happened before. I think his more dominant thought is that either the trough will pick it up and take it out. Or it will completely miss it and allow Bertha to stall off SEUS. Thereafter being directed toward the US coast in 7 to 10.

Disclaimer: This is only my opinion on what JB is saying. In all likelihood this is a complete misinterpretation of what he is saying.

[Blown Away]

Why are we talking about South Florida? Climatologically that result would be one of the rarest storm landfalls in a while and nothing supports landfall there anyway.

Give that a 2% at best.

I agree w/ the 2%, but Bertha is on uncharted grounds rate now.

[pavelbure224]

You have a storm that is continuing going west at a fast pace. So everyone has to pay close attention to Bertha. SE Fl has to watch out like everyone else has too.

[SouthFloridawx]

Okay... I've been out of this for a while. If you don't use it, ya loose it. Well it's certainly true for me.

But looking at the water vapor loop... if the TUTT doesn't pull north, she is going to get sheared. Maybe that is what the ukmet is seeing.

http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_wv_ls_0.html

I think Andrew dealt with a similar type of Upper Low and was sheared, about in that area..

ZCZC MIAWRKAD4 LOC
TTAA00 KNHC DDHHMM
...FOR INTERGOVERNMENTAL USE ONLY...
TROPICAL STORM ANDREW DISCUSSION NUMBER 10
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT WED AUG 19 1992

A RATHER STRONG UPPER LOW NEAR 28N57W...AS INDICATED BY WATER VAPOR
IMAGES...IS INDUCING UPPER LEVEL SHEAR OVER ANDREW. THIS IS
REFLECTED BY THE POSITION OF THE LOW LEVEL CENTER OF THE STORM WHICH
APPEARS TO BE REMOVED FROM THE CONVECTION. THERE ARE SOME
UNCERTAINTIES ON THE LOCATION OF THE LOW LEVEL CENTER BUT THE BEST
ESTIMATE OF THE INITIAL MOTION IS 295/18 OR PERHAPS A LITTLE BIT
FASTER.

THE FUTURE TRACK AND INTENSITY OF ANDREW DEPENDS UPON THE EVOLUTION
OF THE UPPER LOW. WITH RESPECT TO THE INTENSITY...IT APPEARS THAT
THE SHEAR ENVIRONMENT WILL PERSIST AT LEAST FOR THE NEXT 24 TO 36
HOURS. BY THEN...THE MODELS INDICATE THAT THE UPPER LOW WILL BE
LIFTING OUT AND THE SHEAR WILL HAVE DIMINISHED. IF ANDREW IS ABLE TO
PERSIST THAT LONG...THEN SOME SLOW STRENGTHENING MAY BEGIN AND THAT
IS INDICATED IN THE OFFICIAL INTENSITY FORECAST. HOWEVER...IF
VISIBLE SATELLITE IMAGES AND RECONNAISSANCE DATA SHOW THAT INDEED
THE CIRCULATION CENTER IS WELL REMOVED FROM THE CONVECTION..THEN THE
CHANCES OF INTENSIFICATION ARE VERY SMALL.

[Frank2]

But looking at the water vapor loop... if the TUTT doesn't pull north, she is going to get sheared. Maybe that is what the UKMET is seeing.

And, there's a stationary ULL at approimately 25N 55W (that seems to be developing within the TUTT) - stand by for Bertha to get a new 'do (perhaps)...

[gatorcane]

The NHC discussion indicates:

THE NHC FORECAST TRACK ASSUMES THAT BERTHA WILL REMAIN
DEEP ENOUGH TO DECELERATE DUE TO THE WEAKER RIDGE

That's interesting because moving W at 21 mph means she can't deepen all that quickly. The TUTT should also help shear Bertha in the long-run also keeping her from deepening.

The cone was no surprise BTW, shift left in the short-term slightly to reflect the W movement and nudge slightly right in the long-term in response to some of the models.

[MiamiensisWx]

Personally, it appears that the broad TUTT is gradually "lifting out" as the upper low moves NE. Therefore, upper level shear should gradually diminish near the NE Caribbean over the next few days.

http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_wv_ls_0.html

Note the slow "ejection" to the NE. NE Caribbean will be the first area to come within close proximity of Bertha.

[Blown Away]

But looking at the water vapor loop... if the TUTT doesn't pull north, she is going to get sheared. Maybe that is what the UKMET is seeing.

And, there's a stationary ULL at approimately 25N 55W (that seems to be developing within the TUTT) - stand by for Bertha to get a new 'do (perhaps)...

Almost appears the TUTT is beginning to lift out.

[caribepr]

off topic caribepr, but have you noticed that little blob just to the east of the islands around 57W?....hopefully that's just some rain headed our way.....

There is thread going right next to this one on Bertha on tropical waves that you should check out, also you can get the report out of San Juan on weatherunderground for a pretty good *local* forecast (you can get it lots of places, including here - go to the home page here and there is a LOT of stuff to find! - but that is a fast way, just type in STT). We have one wave passing us now and one coming around in a few days. I don't think there's much to it but maybe rain that we need so much (you guys get it and it usually goes right around us).