Post-Tropical Cyclone BERTHA

maquiladora

000
WTNT43 KNHC 010321
TCDAT3

TROPICAL STORM BERTHA DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL032014
1100 PM AST THU JUL 31 2014

Reports from an Air Force Reserve reconnaissance aircraft earlier
this afternoon and evening indicated that the well-defined low
pressure system located about 250 nmi east-southeast of Barbados had
surface winds of about 40 kt north and northeast of the center.
Since the departure of the aircraft, a band of deep convection has
developed near and to the north and east of the low-level center,
and now has enough organization to consider this system a tropical
cyclone.

The initial motion estimate is 290/17 kt. Bertha is moving along
the southern periphery of a strong subtropical ridge located to the
north based on earlier dropsonde data obtained by a NOAA
Gulfstream-IV jet aircraft. The NHC model guidance is in excellent
agreement on the cyclone maintaining a general west-northwestward
motion for the next 48 hours or so, followed by a gradual turn
toward the northwest after that through 96 hours. By Day 5, Bertha
is expected to turn northward as it moves around the western portion
of the ridge. The official forecast track is similar to but slightly
north of the consensus model, TVCA.

The environment surrounding Bertha is not particularly favorable
for significant strengthening during the next two days due
to modest westerly shear and limited mid-level moisture. However,
the cyclone will be moving over increasing SSTs and within an
upper-level atmosphere that is slightly cooler than normal. The
resultant increase in instability could allow for some slight
strengthening to occur before Bertha interacts with Puerto Rico
and eastern Hispaniola in about 48 hours or so. After the cyclone
clears land, some slight re-strengthening is possible based on the
SHIPS model indicating that the vertical shear decreasing to less
than 10 kt and SSTs increasing to near 29C. The NHC intensity
forecast is similar to the consensus model ICON.

FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 12.3N 55.5W 40 KT 45 MPH
12H 01/1200Z 13.2N 58.0W 40 KT 45 MPH
24H 02/0000Z 14.5N 61.4W 40 KT 45 MPH
36H 02/1200Z 16.1N 64.7W 45 KT 50 MPH
48H 03/0000Z 17.9N 67.9W 45 KT 50 MPH
72H 04/0000Z 22.0N 73.0W 35 KT 40 MPH
96H 05/0000Z 26.8N 75.2W 40 KT 45 MPH
120H 06/0000Z 32.0N 74.7W 45 KT 50 MPH

$$
Forecaster Stewart

maquiladora

This is meant to be international weather, not historical. Whoops.

Iancar29

One to watch folks!!

Close to the Bahamas is (soon to strengthen to hurricane) Bertha, this will head east across the Atlantic this week and could affect the weather over the UK at the end of the weekend into the start of next week. But a lot of uncertainity as it is a long way off, still way out west, plenty of forecast paths and model solutions which will change a lot over this week. There is a chance of wet and windy weather from the SW linked to the remnants of this system but we've got plenty of other weather coming at us before that. And Bertha could go south and miss us all together. Remember we don't get hurricanes in the UK , although we can get exceptional (hurricane force) winds in Autumn storms. Keep an eye on the forecasts this week

ninebeanrows

Bertha as an nasty early Autumn extra-tropical low approaching our shores next Sunday.

Iancar29

I guess my post didnt appear properly no? lol

Video

Very low pressure on this one, what kind of winds are we talkin here?

droidman123

Iancar29 wrote: »

One to watch folks!!

Only the uk? Would this not affect ireland as well? Surely we would be first in the firing line?

Birdnuts

I think Bertha will tickle us in some shape or form. Its been a good few years now since ex-hurricanes have had any noticeable impact on the country.

Iancar29

droidman123 wrote: »

Only the uk? Would this not affect ireland as well? Surely we would be first in the firing line?

Of course yeah ! , though you know what english weather providers when it comes to mentioning us lol :rolleyes:

I have a feeling this will change A LOT before the date , but as always its exciting to watch the developments either way

RED L4 0TH

Reaching the SW early Sunday according to the latest GFS run. Long way to go yet though.

DOCARCH

Quote the Eagle just now, on the 7.55 forecast on RTE Radio 1:

'...showers die down for the weekend as a major storms passes to the south of us.'

He sounded very confident??? It's only Monday!!!

The Express says different...http://www.express.co.uk/news/nature/495557/UK-weather-forecast-tropical-storm-bertha-from-bahamas-to-hit-Britain

maquiladora

DOCARCH wrote: »

Quote the Eagle just now, on the 7.55 forecast on RTE Radio 1:

'...showers die down for the weekend as a major storms passes to the south of us.'

He sounded very confident??? It's only Monday!!!

The Express says different...http://www.express.co.uk/news/nature/495557/UK-weather-forecast-tropical-storm-bertha-from-bahamas-to-hit-Britain

The forecast is based on the ECM, and the latest ECM shows the remnants of Bertha passing to our south at the moment. It's several days away so the track could change more northerly, or it could end up fizzling out over the Atlantic and not being anything noteworthy at all.

RED L4 0TH

maquiladora wrote: »

It's several days away so the track could change more northerly, or it could end up fizzling out over the Atlantic and not being anything noteworthy at all.

True. Latest GFS run at +120 hrs is already pushing it north. Wouldn't be a pleasant Sunday if it turned out to be accurate though.....

Hooter23

https://uk.news.yahoo.com/hurricane-bertha-miss-us-other-possible-storms-being-171458800.html

Kermit.de.frog

The problem here would be flooding potential. This air is sub tropical and laden with moisture. It's up in the air right now but there is that risk that at some stage on Saturday evening, night some very heavy rain could occur and it's something that needs watching.

The 12z GFS is an outcome




The other outcome is it goes south altogether.

I wouldn't justify media coverage with a response tbh.

Coles

Heavy rain could be a problem with the ground saturated after the last few days.

RED L4 0TH

Latest GFS run for Sunday morning.

Zzippy

Coles wrote: »

Heavy rain could be a problem with the ground saturated after the last few days.

Not in the west it's not! Local river as low as it gets, could do with a good drop of rain... Dublin got 80mm or so the other day, we got about 6!

Video

Zzippy wrote: »

Not in the west it's not! Local river as low as it gets, could do with a good drop of rain... Dublin got 80mm or so the other day, we got about 6!

Speak for your own personal location , we've had too much rain lately here

KingdomRushed

Video wrote: »

Speak for your own personal location , we've had too much rain lately here

Err he clearly was speaking for his own location

RED L4 0TH

6Z GFS run. Moving to the south again.

maquiladora

RED L4 0TH wrote: »

6Z GFS run. Moving to the south again.

Gusts of up to ~110km/h for Cornwall there if that verified.

RED L4 0TH

maquiladora wrote: »

Gusts of up to ~110km/h for Cornwall there if that verified.

50 knot wind arrow on the mean speeds chart west of the Cornish coast.

Hooter23

http://www.metoffice.gov.uk/news/releases/archive/2014/bertha

ninebeanrows

Still think this could go further north.

Wouldn't pay too much attention to that MetO track chart. Bit off I reckon.

Harry Palmr

Like you'd know better than 100,000,000 quid of computing power!

Red Nissan

Harry Palmr wrote: »

Like you'd know better than 100,000,000 quid of computing power!

In any particular situation, local knowledge and historicity may actually do exactly that.

Don't forget that 'Global Warming' was also from multi-million dollar machines and teams of researchers who specifically fed information into the moddelling software to back up a theory.

Obviously not the case here, in this Bertha tracking event, nonetheless, a vital piece of information not inputted into the software will yield the results of the formula its fed.

rainbow kirby

Really not liking that most probable track, will cause serious trouble for anyone doing the RideLondon 100 on Sunday...

ninebeanrows

GFS has it a bit further north but not too intense

DOCARCH

Weathercheck wrote: »

GFS has it a bit further north but not too intense...

...still a possible drenching for the east coast (again).

Harry Palmr

I think we can safety write this one off, likely to get more rain tomorrow than from this.

Kermit.de.frog

Ok it now looks a higher probability of intense rainfall on Saturday night and with the water table at a fairly high level there are real issues for the south and east potentially.

ME's forecast is off.

Red Nissan

rainbow kirby wrote: »

Really not liking that most probable track, will cause serious trouble for anyone doing the RideLondon 100 on Sunday...

Meteo News this am is desperately trying to downplay the effects, but it does look like high winds and heavy rain.

Iancar29

GFS has just taken a big wobble towards the ECM solution!

ninebeanrows

Yea, this track would be outside MetOs 10% risk northern track yesterday.

This would look a lot more threatening in GFS meso WRF when it updates.

maquiladora

Latest HIRLAM keeps it well to our south. Some strong winds in a narrow windfield heading for the far southwest of England here. Just a boring wet day here, but at least the strongest rain would stay offshore to the south, if this verified.



HIRLAM usually handles these type of things better than the lower res global GFS, but still a couple of days away yet so things can change.

vickers209

Met eireann getting concerned?

STATUS YELLOW

Weather Advisory for Munster and Leinster

Risk of heavy rain on Saturday night and Sunday, mainly in coastal counties. Details uncertain at present.

Issued:

Friday 08 August 2014 12:00

Valid:

Sunday 10 August 2014 00:01 to Sunday 10 August 2014 15:00

Kermit.de.frog

12z model runs should give a clearer picture. I think the south and east are most at risk from significant disruptive rainfall. I think ukmo has it tracking too far south.

maquiladora

vickers209 wrote: »

Met eireann getting concerned?

STATUS YELLOW

Weather Advisory for Munster and Leinster

Risk of heavy rain on Saturday night and Sunday, mainly in coastal counties. Details uncertain at present.

Issued:

Friday 08 August 2014 12:00

Valid:

Sunday 10 August 2014 00:01 to Sunday 10 August 2014 15:00

Thats because the current HIRLAM track keeps the heavy rain off the coast, but any shift in the track further north would bring that rain onto the southern coastal areas.

ninebeanrows

NMM 6z shows the potential for some very strong winds for the time of year ( 90km gusts at this time of year can bring down trees)



Wind Gusts @ 10m



Clearing eastwards

Lumi

Nice animation from EUMETSAT showing the remnants of Bertha making their way towards Europe

https://www.youtube.com/watch?v=TmzTui3frzE

Iancar29

Weathercheck wrote: »

NMM 6z shows the potential for some very strong winds for the time of year ( 90km gusts at this time of year can bring down trees)

Oh and would ya look at that , im off work for a week on Sunday


My storm chase senses be tingling !

ninebeanrows

First time in a while I have been anticipating a set of output.

A very uncertain Forecast but potentially a significant weather event.

-12z GFS isn't as intense as 6z.

Kermit.de.frog

This is serious rainfall.



42 hours out. Time for proper warnings.

ninebeanrows

The Lower res GFS picking up widespread 50mm with >60mm im parts.

So interesting to see how high the NMM high res goes later

maquiladora

12Z GFS is weaker and tracking a little further south than the 06Z.

12Z HIRLAM maintains the southerly track, gales only for southwest England, and weaker on this run than the 06Z.



Southerly track again keeps the heavy rain off the south coast here.



A non-event for here if that verified. A north shift in track and it'll be very wet and miserable in the south.

Weathercheck

Weathercheck wrote: »

The Lower res GFS picking up widespread 50mm with >60mm im parts.

So interesting to see how high the NMM high res goes later

What about that bit to the east of Scotland earlier? Could it have any impact passing over here.

Brown Podzol

Just had a look at the forecast on Sat 24 and the heavy rain is forecast to move in over the southwest and move north over the western counties through Sunday. Any comments. Over here briefly from the farming where the weather dictates almost everything we do.

Rock Lesnar

Haven't been on here today and the last i read of this yesterday it seemed like it was passing to the south and practically missing us.

Are we getting it now?

Harry Palmr

BBC/Met latest sez it'll move along the south coast of England and up the east coast.

Rock Lesnar

Harry Palmr wrote: »

BBC/Met latest sez it'll move along the south coast of England and up the east coast.

Ive given up on them, i saw their forecast for last weekends rain and it was missing us here on the east coast and staying in the irish sea