Storm Lorenzo: October 3/4 2019 **Technical Discussion Only**

KingdomRushed

What interests me is whether even a direct hit from Lorenzo will equal a significant storm? Given all models showing it to be filling rapidly at that point. I will tell you something, since the public service brought in the ‘red warning means a day off’ rules, the interest in these storms has never been more palpable, a nation of clerks await the magic email.

Gaoth Laidir

Latest water vapour shows that trough coming off NE Canada and its westerly flow starting to interact with Lorenzo.

Gaoth Laidir

The 00Z ECM in 3-hourly steps has gusts of up to 140 kph just in around Belmullet, 120-130 kph down Galway to Clare coast, but much less inland and everywhere else. Friday morning around 70-80 kph is the highest in the east

NIMAN

Pangea wrote: »

The North West is Ireland too.

Agree, as a resident of the nw.

You only have to look at our roads infrastructure, railways, general investment etc to think we weren't part of Ireland, but that's an argument for another forum.

uck51js9zml2yt

[Deleted User] wrote: »

Tatranska, better batton down the greenhouse.

Not up yet thankfully.

SleetAndSnow

Looking at the charts, I’d say us southern folk (Cork, Kerry and maybe Waterford) shouldn’t get it too bad unlike Ophelia. Even when it comes back over the country it looks to be about 70km/80 Max for us down here but track could change as Ophelia did on the day missing Mayo

Villain

Some better agreement on GEFS this morning, looking like mainly a West coast event at present but given it is still a Cat2 it is hard to call intensity with detail.

dulpit

At what point would it be clear how this will affect South of Ireland and particularly Cork Airport? Flying home from holidays in Thursday afternoon into ORK...

DOCARCH

dulpit wrote: »

At what point would it be clear how this will affect South of Ireland and particularly Cork Airport?

Thursday! :pac:

At this point, looks like no more than a regular windy autumn day/regular autumnal gale.

However, just needs to be monitored to watch/see that it decreases in intensity as envisaged/forecast and/or watch for track changes.

John.Icy

KingdomRushed wrote: »

What interests me is whether even a direct hit from Lorenzo will equal a significant storm? Given all models showing it to be filling rapidly at that point. I will tell you something, since the public service brought in the ‘red warning means a day off’ rules, the interest in these storms has never been more palpable, a nation of clerks await the magic email.

Yep they will bay for a day off in the buildup and on D-day will be top of line wondering what the fuss is over, tis only a bit of wind, MetE are useless.

Jpmarn

It now looks like it will just be a rather wet and windy day in the Limerick area. I think the chance of severe weather there is no more than 20%. I might be more afraid in the north west region from Mayo to Donegal where chance of severe weather is around 50%.

Villain

Latest ECMWF Ensemble chart:

m17

Say my name

Villain wrote: »

Latest ECMWF Ensemble chart:
]

I see in that forecast chart it has the center pressure dipping to 950 hPa on Thursday.

Is that the lowest forecast hPa among the main forecasts for Thursday?

Villain

Latest NHC update:

DISCUSSION AND OUTLOOK

---

At 500 AM AST (0900 UTC), the center of Hurricane Lorenzo was
located near latitude 33.4 North, longitude 39.7 West. Lorenzo is
moving toward the northeast near 22 mph (35 km/h). The hurricane
should move in the same general direction but at a faster forward
speed during the next few days. On the forecast track, the center
of Lorenzo is expected to pass near the western Azores early on
Wednesday.

Maximum sustained winds are near 100 mph (155 km/h) with higher
gusts. Only slow weakening is expected during the next 48 hours.

Lorenzo is a very large tropical cyclone. Hurricane-force winds
extend outward up to 90 miles (150 km) from the center and
tropical-storm-force winds extend outward up to 345 miles (555 km).

The estimated minimum central pressure is 962 mb (28.41 inches).

Hurricane Lorenzo Discussion Number 36
NWS National Hurricane Center Miami FL AL132019
500 AM AST Tue Oct 01 2019

Lorenzo's eye has become less distinct on satellite images over the
past several hours, but the system remains very well organized with
tightly curved convective bands. The upper-level outflow remains
quite well-defined. The advisory intensity, 85 kt, is a blend of
subjective Dvorak estimates from TAFB and SAB along with ADT values
from UW-CIMSS. Sea-surface temperatures beneath the cyclone are
likely to fall below 20 deg C within 36 hours, along with a large
increase in vertical shear. Since Lorenzo has such a large
circulation, it will probably be slow to weaken, however. In 48
hours or less, the global models show the system merging with a
frontal zone, indicating the transition to an extratropical
cyclone. The NHC intensity forecast is on the high side of the
numerical guidance but still weakens the cyclone below hurricane
strength when it nears Ireland and Great Britain. By 96 hours, the
cyclone should dissipate over Europe.

The hurricane continues to accelerate, and is now moving
northeastward near 19 kt. Continued acceleration on the southeast
and east side of a large mid-tropospheric trough over the central
north Atlantic should occur over the next day or two. In 72 hours
or so, the cyclone is expected to turn east-northeastward while
moving in the westerly flow ahead of the north Atlantic trough.
There is still significant track model divergence around this time,
and the official 3-day forecast is somewhat southeast of the model
consensus. This leans toward the latest ECMWF solution, which
continues to be on the southeast side of the track guidance
envelope.

Lorenzo is producing huge seas over the north Atlantic. Full
information on the High Seas Forecasts can be found at the Ocean
Prediction Center under AWIPS header NFDHSFAT1, WMO header FZNT01
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php.
The UK Met Office also has information in High Seas Forecasts issued
by under WMO header FQNT21 EGRR and on the web at

pauldry

Not a damp squid yet

Hope cold ocean fills it

Dont feel like a storm

Mortelaro

Villain wrote: »

Latest NHC update:

Essentially following a route that a bigger amount of clusters suggested days ago,a win for ensemble use? And actually reasonably predictable
One is not out of the woods yet though of course

JanuarySnowstor

Direct hit on latest icon

limericklad87

pauldry wrote: »

Not a damp squid squib yet

all squids are damp!!

highdef

JanuarySnowstor wrote: »

Direct hit on latest icon

Must check again as I looked only ten minutes ago and it was showing a prime case of "nothing to see here".

ninebeanrows

Not too much clarity this morning but certainly increased risk of Lorenzo coming close to Ireland bringing some impacts. Still high degree uncertainty where it will turn right and how fast it will decay once it moves way from the left exit of the jet-streak.

Still all to play for at this point but must be stressed very minimal risk of a red level event.

Also important to stress Lorenzo will be well ex-tropical when it hits the vicinity of Ireland and is infact only a possible danger due to typical cold cyclongenesis

But still risk of Orange cat winds in parts.

pad199207

Sleety_Rain wrote: »

Not too much clarity this morning but certainly increased risk of Lorenzo coming close to Ireland bringing some impacts. Still high degree uncertainty where it will turn right and how fast it will decay once it moves way from the left exit of the jet-streak.

Still all to play for at this point but must be stressed very minimal risk of a red level event.

Also important to stress Lorenzo will be well ex-tropical when it hits the vicinity of Ireland and is infact only a possible danger due to typical cold cyclongenesis

But still risk of Orange cat winds in parts.

Expecting a Yellow Warning for Kildare anyways

ninebeanrows

as an aside, conditions felt in coastal Dublin today will probably be worse than that brought to coastal Dublin by the remnants of Lorenzo.

ninebeanrows

GFS 6z brings the filling feature in over Ireland.

73bc61lyohr0mu

Sleety_Rain wrote: »

GFS 6z brings the filling feature in over Ireland.

Is that 2 am Irish time? I've to drive a big van from Limerick to Dublin at 1am Friday morning and it might be a scary experience if this bollox is blowing about..

ninebeanrows

GFS would bring 65kt gusts into coastal Mayo, 50kt gusts inland

naughto

Sleety_Rain wrote: »

GFS 6z brings the filling feature in over Ireland.

What about the ball of rainthat’s coming behind it

JanuarySnowstor

Big upgrades from both gfs and icon. They have both now gone for the undercut and the euros now look like the winner
GAME ON!!😅

TTTT

Gaoth Laidir wrote: »

This article describes why Debbie was not tropical when it hit Ireland.

https://irishweatheronline.wordpress.com/2015/10/28/blast-from-the-past-hurricane-debbie-1961/

Is it possible that Lorenzo will interact the same way before it reaches us?

Gaoth Laidir

TTTT wrote: »

Is it possible that Lorenzo will interact the same way before it reaches us?

Yes, although Lorenzo will most likely be moving a bit slower than Debbie so less of an effect of this motion will be felt to the east of the centre. A lot of the high winds with Debbie was as a result of its very fast movement northeastwards.