Tropical Storm Bertha Model Runs

[RL3AO]

I still think models are going to once again underestimate the strength of that ridge....Trofs that deep are not very common down here this time of the year. I think if Bertha is still moving due WEST tomorrow....then its really time to wonder about the mainland. I am not sure either way....

Do you remember/find out how the UKMET did with Dean and Felix last year when the other models were saying GOM?

[Derek Ortt]

I explained the problem in the evening forecast

[Blown Away]

The models seem to be somewhat agreeing w/ Bertha recurving. Everyone seems to be putting all the stock into the Ukmet and it's all alone w/ the W track. Most models see a strengthening Bertha that will slow down and start a WNW to NW turn, rate now we have a marginal shallow TS racing due W. The trend is almost all the models shifting right and I don't think that can be ignored.

[MiamiensisWx]

The models seem to be somewhat agreeing w/ Bertha recurving. Everyone seems to be putting all the stock into the Ukmet and it's all alone w/ the W track. Most models see a strengthening Bertha that will slow down and start a WNW to NW turn, rate now we have a marginal shallow TS racing due W. The trend is almost all the models shifting right and I don't think that can be ignored.

Why are you discounting Bertha's current westward movement simply because of some models' trends?

I do agree with an eventual recurvature near the Southeast coast, but your assumption seems slightly premature.

[deltadog03]

I am not saying its NOT going to recurve....To be honest...Its a tough thing to figure out right now...

[txwatcher91]

Yesterday the models were shifting west and today they are shifting east. Tomorrow they may shift back west or they may go more east, we just have to wait and see. Personally, I think more west right now.

[ronjon]

Well climatology would agree on a recurvature scenario. If it strengthens to a hurricane, I'd say the odds are for recurvature well away from the US coast. The UKMET is a southern outlier at the moment. But the GFDL did have a tendency last year to go poleward - remember how it wanted to take Dean and Felix into La. A couple more days and it'll become fairly certain which way it'll go. Any bets we see a major hurricane from Bertha?

[Aric Dunn]

oh let me add something.... the weakness in the mid level ridge that was supposed to turn berth is no long really around .. even if bertha strengthened now it is unlikely that she would turn before 60w the ridge in both the low and mid levels is very much in place and westward track for at least the next 36hrs is very likely.. no matter the strength. there after is a different story and that all depends on the trough that is very uncertain since it may not be strong enough to erode the ridge enough.

[NDG]

Bertha better start slowing down if a recurvature towards Bermuda or east of Bermuda is to happen.
18z gfs out the window, it tracks Bertha to take 48hrs to get to 50W, that would mean that tomorrow she has to slow down to 18mph and Tuesday no more than 16mph.

[Derek Ortt]

there is a weakness in the ridge at 55W... however, it should not be enough to force recurvature

[Aric Dunn]

oh then at that point her strength will be important again.. maybe.. as a weaker system would stay farther south .. but given the uncertainties .. it would be prudent to just keep an eye on the short term forecast and see how far north she wobble cause that will play a big role... its beeter to due a series of short term forecast that builds on them selves giving you better long term forecast down the road//

[Aric Dunn]

there is a weakness in the ridge at 55W... however, it should not be enough to force recurvature

ok yes .. but in comparison to what was forecast it is almost irrelevant at this point..

[ronjon]

I think Derek's reasoning is sound given the forward speed. I like the NOGAPS track as this model usually respects ridge features. I agree it'll probably get just north of the Leewards - say 22N, 60W. After that, it's just too soon to tell since the global models don't have a real good handle on the extent of the east coast trough in 5-6 days.

[Aric Dunn]

THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT
36-48 HOURS COURTESY OF A STRONG RIDGE TO THE NORTH. THEREAFTER...
THE CYCLONE BEGINS TO ENCOUNTER A WEAKNESS IN THE SUBTROPICAL RIDGE
AND TRACK MODELS DIVERGE SIGNIFICANTLY.

exactly what i said.

['CaneFreak]

THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT
36-48 HOURS COURTESY OF A STRONG RIDGE TO THE NORTH. THEREAFTER...
THE CYCLONE BEGINS TO ENCOUNTER A WEAKNESS IN THE SUBTROPICAL RIDGE
AND TRACK MODELS DIVERGE SIGNIFICANTLY.

exactly what i said.

no it isn't!!!! Don't lie Aric!!! You are good at lying!!!

[MiamiensisWx]

The following post is NOT an official prognosis.

It honestly looks like the upper level ridge is already building west as the TUTT quickly lifts out of the area. Note that Bertha's forward movement during tomorrow and the next few days is going to exert some significant influences in regards to its track. Currently, a shortwave trough at H5 is moving east from the Ohio Valley to the Mid-Atlantic region. Water vapor imagery of the upper levels indicates the shortwave trough is moving rather rapidly to the east as the weak H5 vort max transects the area. The fast northern stream suggests the shortwave trough will exit the Mid-Atlantic fairly quickly, allowing the upper level ridge to H5 to re-assert itself and briefly build to the west. This trend may likely commence as soon as tomorrow and the following day. If you combine the unfolding current situation with an extrapolation of Bertha's ongoing rapid movement, it could indicate that Bertha may be closer to the CONUS earlier than some people anticipate. Bertha has been persistently moving further west faster than expected over the past ~24-36 hours. I highly doubt that Bertha will only come within a certain distance of the CONUS by late next week. After analysis of current trends and the pattern, it appears that it may occur earlier than that time frame. Depending on the timing of the next H5 trough progged to affect the East and the amplification of the upper ridge in the West, Bertha could certainly pose a threat to the Southeast (primarily North Carolina).

One possible concern in regards to the intensity is the fact that a small upper low NE of Bermuda is moving SSE as the TUTT moves NE. This new upper low could deepen and develop a new TUTT (the second one progged by the operational GFS at 200-250 mb?) over the next few days in a similar position to the current TUTT. This could increase the upper level divergence/shear in the vicinity north of the Leeward Islands and Puerto Rico. Therefore, after gradual intensification, Bertha's intensity could fluctuate in that area. That leads to the possibility of a more southerly and westerly track in the long range, depending on the actual intensity of Bertha at that time and the degree of the possible TUTT's influence.

I'm not a person who casually ignores or disputes models, especially if they are latching on to a pattern. I also regularly utilize climatology in my analysis. However, based on all available evidence, I believe it is premature to sound the all clear for the Southeast. It is also premature to make a definite statement that Bertha will strike the CONUS, Bermuda, the NE Caribbean, or any land mass. Both approaches should be discouraged, especially given the considerable uncertainties and complexities involved. Everyone should be prepared, regardless of their location. The evolution of this system, the analysis of the models, and the "kinks" thrown in to the synoptic pattern will present an exceptionally fascinating and extremely intriguing situation. Regardless of the final result, Bertha will present an incredibly tough forecasting challenge and a bastion of knowledge for everyone involved. This system has already been impressive itself.

[Aric Dunn]

THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT
36-48 HOURS COURTESY OF A STRONG RIDGE TO THE NORTH. THEREAFTER...
THE CYCLONE BEGINS TO ENCOUNTER A WEAKNESS IN THE SUBTROPICAL RIDGE
AND TRACK MODELS DIVERGE SIGNIFICANTLY.

exactly what i said.

no it isn't!!!! Don't lie Aric!!! You are good at lying!!!

what?? scroll up ad read. well not word for word.. duh

[cycloneye]

Ok lets cut it there,both.

[Aric Dunn]

:uarrow: Ok lets cut it there,both.

huh? im confused

['CaneFreak]

:uarrow: Ok lets cut it there,both.

huh? im confused

I am too actually.....