part 1 - September: Brief Indian Summer then ex-Tropical Storm Laura
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What does one
do when it's been seemingly raining for several weeks and then the sun
comes out for a ten-day period?? Have a holiday, of course! Now, for me
the likes of Ibiza have little if any appeal - all the stress of
crowded airport lounges, queuing, noise, heat..... the idea of a
holiday is to recharge the batteries is it not?
beautiful late September day I describe below certainly did that for
me! Meanwhile the hurricane season is in full swing down in the
Tropical Atlantic, and most years we get some remnants of these storms
heading our way. On October 4th-5th exactly that happened, and a quite
spectacular episode of flooding resulted. More on these tropical
deluges further down the page: first, welcome to Cardiac Hill:
Cardiac Hill is the anglers' nickname for the very south-western tip of
the Lleyn Peninsula, beyond Aberdaron and facing the island of Bardsey
across the rip-tides of the notorious Sound. Its name comes from the
ascent back up when, weary after a good day's fishing, and with the
catch adding to the weight of the rucksack, grown men are reduced to
staggering along, frequently stopping to lean on their rods and catch
breath! This is near its top.....
Covered in sheep and rabbit-cropped heather and gorse, it is also a
good place for Parasol Mushrooms, which are very tasty when fried with
a bit of bacon!
This shot (with the sun behind me) is about halfway down looking
towards one of the fishing platforms. Beyond, the disturbance on the
sea surface is the powerful tide-rip that occurs here as the tide is
The final 40m of the descent is on steep grass at first before rocky
ribs lead down to a steep scramble onto the platform itself. In dry
weather this is straightforward with care, but in the wet both grass
and rock take on a teflon-like feel: in such conditions I avoid the
place out of a preference to stay alive!
The tide-rip sweeps up small fish around the point and predators lie in
wait downtide, charging in and swallowing their prey whole. To catch
here, you have to use lures that the fish mistake for such prey.
Sometimes there are lots of mackerel here: on this occasion it was
pollack that I caught. A member of the cod family, but much fiercer
beasts, pollack are good eating provided you clean the catch soon after
it is caught. The fillets from these fish are in the freezer awaiting a
go on my fish-smoker.
Low tide arrived and the
rip died away, so I moved over to St Mary's Well Bay, where you can
bait-fish for a range of species, and lazed away a perfect afternoon.
Choughs flying overhead in aerobatic groups, all manner of seabirds out
there over the waves, seals and quite often dolphins and porpoises -
this place is as close to perfection as makes no difference!
Eventually it was time to
head home, so I wandered back up across the ancient field-systems in
evening light, to say farewell to Bardsey until the next time. October,
and stormy conditions, was just days away.
And so to Laura's visit.
This was the discussion (they are always in capitals) released by the
National Hurricane Center on 28th September - the day after my trip to
THUNDERSTORMS ASSOCIATED WITH A LARGE NON-TROPICAL LOW LOCATED OVER THE
CENTRAL NORTH ATLANTIC OCEAN ABOUT 700 MILES WEST-SOUTHWEST OF THE
WESTERNMOST AZORES ISLANDS ARE SHOWING SOME SIGNS OF ORGANIZATION. THIS
SYSTEM IS SLOWLY ACQUIRING TROPICAL CHARACTERISTICS AND HAS THE
POTENTIAL TO BECOME A SUBTROPICAL OR TROPICAL CYCLONE OVER THE NEXT
COUPLE OF DAYS AS IT MOVES GENERALLY WESTWARD AT 10 TO 15 MPH.
This was to become Tropical Storm Laura. Tropical storms are defined as
of strong thunderstorms with a defined circulation and maximum
sustained winds of 39 to 73 mph (34-63 knots). Above those windspeeds,
you have a hurricane.
storms and hurricanes characteristically have am east to west track,
gradually turning north, from their area of origin in the mid Atlantic
off the west coast of Africa. This is why they tend to move into the
Caribbean and then curve N to hit the southern USA. Sometimes this
curve occurs sooner, sometimes later: if sooner then the storm may not
make landfall, remaining out at sea, and termed in meteorological slang
as a "fish" (nothing to do with Michael Fish incidentally). Laura did
exactly that. The final NHC discussion on October 1st was as follows:
TROPICAL STORM LAURA DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122008
1100 AM EDT WED OCT 01 2008
ALTHOUGH A SMALL PATCH OF CONVECTION REMAINS...THERE IS NOT ENOUGH DEEP
CONVECTION FOR LAURA TO BE CONSIDERED A TROPICAL CYCLONE...AND THIS
WILL BE THE LAST ADVISORY. I RATHER LIKE THE CANADIAN HURRICANE
CENTER'S TERM POST-TROPICAL...WHICH SIMPLY MEANS NO LONGER
TROPICAL...TO DESCRIBE WHAT LAURA HAS BECOME. THERE IS NOT REALLY
ENOUGH EVIDENCE OF FRONTAL STRUCTURE YET TO CONSIDER LAURA
EXTRATROPICAL IN THE TRADITIONAL SENSE...AND SOME USERS MIGHT INFER A
WEAK SYSTEM IF WE USED THE TERM REMNANT LOW...WHICH IS MOST-COMMONLY
APPLIED TO DECAYING SYSTEMS IN THE EASTERN PACIFIC BASIN.
A QUIKSCAT PASS THIS MORNING SHOWS THAT THE MAXIMUM WINDS REMAIN NEAR
40 KT...PERHAPS EVEN A BIT HIGHER. A TRANSITION TO A FULLY
EXTRATROPICAL STRUCTURE IS EXPECTED OVER THE NEXT DAY OR SO...AND THE
GFS SUGGESTS SOME REINVIGORATION OF THE EXTRATROPICAL REMNANT
OF LAURA IN THREE OR FOUR DAYS. OTHER GLOBAL GUIDANCE...HOWEVER...
SHOWS THE CIRCULATION BECOMING ELONGATED AND DISSIPATING WITHIN A
FRONTAL ZONE. THE OFFICIAL FORECAST WILL CALL FOR AN EXPANSION OF THE
WIND RADII IN GENERAL AGREEMENT WITH THE GFS...BUT FOLLOWS A
CONSENSUS OF THE GLOBAL GUIDANCE IN CARRYING A TRACK ONLY OUT TO 72
FORECAST POSITIONS AND MAX WINDS
INITIAL 01/1500Z 46.5N 46.5W 40 KT...POST-TROPICAL
12HR VT 02/0000Z 48.9N 45.6W 40 KT...EXTRATROPICAL
24HR VT 02/1200Z 52.2N 43.5W 40 KT...EXTRATROPICAL
36HR VT 03/0000Z 55.0N 39.8W 40 KT...EXTRATROPICAL
48HR VT 03/1200Z 56.0N 33.0W 40 KT...EXTRATROPICAL
72HR VT 04/1200Z 56.5N 20.0W 40 KT...EXTRATROPICAL
96HR VT 05/1200Z...ABSORBED
This was in reasonable agreement with the forecast track from the day
does this mean in terms of weather here?
Wind, maybe, but in particular moisture - and lots of it! What
typically happens is that such tropical systems run into the conveyor
of Atlantic depressions that move west-east across the ocean before
arriving here in the UK bringing the wet and windy weather we often
have. They become entrained into such systems and are finally absorbed
by them, but because of their tropical origin, where warm seas allow
for lots of evaporation of water into warm air that can carry more
moisture than cold air, they bring stacks of that moisture with them.
In turn, upon meeting the hills of the western UK, the warm moist air
cools rapidly and dumps its payload of moisture as prolonged torrential
A damp to wet Saturday 4th went downhill in the evening as prolonged
heavy, squally rain set in and lasted the night. Warnings had been
issued for 50-100mm of rain over the Welsh mountains - that's two to
four inches - a lot for one night. The rain cleared to beautiful blue
skies by mid-morning on Sunday 5th so I set out to record the flooding
that I knew would have happened....
What I met with was a flood on quite a big scale - as bad as anything I
have seen in the valley. Here is the forecourt of Station Garage and
the railway bridge over the A487 that heads out to Dyfi Bridge, half a
mile from here. There is a dip in the road under the bridge, to allow
lorries to pass under, and in this image there would have been getting
on for a metre of water under there. Drivers of lorries, vans and 4x4s
get caught out here regularly, taking an optimistic run at the water
and conking out, sometimes (with diesel engines) with major push-rod
damage if their air-intake has pulled water into the cylinders. Every
time this spot floods, there are several cases of "bent engines". The
moral is - if it says "Road Closed" it means just that!!
Some rail disruption was also occurring with people waiting for buses
for the next stage of their journey. The water-filled valley is visible
Here is the view from the end of the platform, looking out over the
A487. This dryer section after the bridge is deceptive as just
afterwards one gets to "the rapids".....
I walked down from the station to the other side of the railway bridge
and out to the rapids....
Here, the full force of the water running along the flood-plain is met
with. The shallower bit here is incredibly swift-flowing. You would
have a job to wade it even though it's only a foot deep at best. People
have been swept away here before.....
....but with care it is possible to get some interesting shots...
...with the detail in the way the water flows a prime focus for the
The above four images were taken at about
1300 - at the time high tide was occurring 10 miles away at the river's
mouth. The tide ponds the water in, even though it was only a small
neap this time.....
|This was taken three
hours later, with the outgoing tide letting water-levels drop quickly.
It was now possible to wade the rapids, but even then the water was
powerful enough to be felt.
Rainfall totals look to have been well into the upper part of the
forecasted 50-100mm*, so
this was a good call by the Met Office and
other forecasting agencies. Well done to them! This morning (6th
October), the charts for the coming weekend hint at a chance of some
kinder weather, warmth and sunshine. Let us hope so, before too much
dust has gathered on my fishing rods!
* Roger McLennan of the Centre for
Alternative Technology, 3 miles NNE of Machynlleth, maintains a
rain-gauge there and he has recently reported to me that the event
produced 92mm of rain. Thanks, Roger!
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