NIMAN Registered User
#16

Entry #8, 2012

I remember that night well. I couldn't sleep, never heard sustained wind like it. I thought the house was going to suffer structural damage for sure.

Was out twice with my flashlight during the night to see if any of the roof tiles were off!

It was the fact that it was continual wind that was scary. I think I heard on local radio in the days after that there was a 1hr period during that night when the average wind speed was above 90mph.

I would have hated to been around during entries 1-7

M.T. Cranium Registered User
#17

For my research interests, I had a look at full and new moon dates close to the list of Malin Head gusts over 80 knots that GL supplied.

I have left out those entries which appear to be consecutive-date second appearances of the same event. That reduces the list from 44 to 38.

That reduces the list to these events, separation from nearest full or new moon shown (from tables of full and new moon dates in house here at the Craniatorium).

Rank is from the original table, missing cases are the two-day events. These are also shown in the form of two ranks (e.g. 4-5 Feb 1957, ranks 3 and 16). Such events are presumed to have peaked close to midnight between the dates unless map inspection suggested otherwise. The lower ranked of the two consecutive dates is in brackets (e.g., 4th Feb 57 was ranked 16th, 5th Feb 57 was ranked 3rd).

Event 5 is shown after event 3 because it was 5-6 days earlier and related to the same lunar date.

Event 28 is shown after event 15 because it was just 1.2 days earlier and linked to the same lunar date. Map inspection reveals two separate storms. The event on the 11th peaked late in the day and the event on the 13th peaked early in the day but they were separated by a transient ridge and each had its own low centre.

Events 29 and 30 and 41, 42 are together in the list anyway, but would have been linked as were the above pairs, as they are also two days apart and linked to the same lunar date. These four were part of a very active wave train that followed in the wake of record low pressure north of the Faeroes (930 mb) around the 11th-12th. It must have been fairly windy at Malin Head from that also, but not quite enough to make the list used here.

Events 29, 30, 39 and 40 are all related to the same lunar date.

Separation from the nearest full or new moon is based on the elapsed time from peak intensity (from map inspection using 6h maps on wetterzentrale NOAA archives) to the lunar date.

Analysis follows the list.

RANK __ DATE _____ Closest full or new moon __ Separation (time of max winds based on map inspection)

01 _____ 16-09-61 ____new __ 10-09-61 03z ______new + 6.5 d
02 _____ 26-12-98 ____full ___02-01-99 03z ______ full - 6.4 d
03,16_(04)05-02-57___ new __ 30-01-57 21z ______new + 5.1 d
__ 05 ___31-01-57 ___ new __ 30-01-57 21z ______ new + 0.9 d
04 _____ 06-11-96 ___ new __ 11-11-96 04z ______ new - 5.0 d
06,09 _14(15)-01-68 __ full __ 15-01-68 15z ______ full - 0.6 d
07,23 _(08)09-01-08 __ new __08-01-08 12z ______new + 0.6 d
08 ______03-01-12 ___ full___ 09-01-12 08z ______full - 6.0 d
10,22 _02(03)-03-82___full __ 09-03-82 21z _______full - 7.0 d
11 _____ 20-03-86 ____full __ 26-03-86 03z _______full - 5.7 d
12,37 _13(14)-01-65___full __ 17-01-65 14z _______ full - 3.8 d
13,38 _(16)17-12-79 __ full __ 19-12-79 08z _______new - 1.9 d
14 ____ 28-01-74 ____ new __ 23-01-74 11z ______ new + 4.8 d
15 ____ 13-01-84 ____ full ___ 18-01-84 14z ______ full - 5.5 d
__28 __ 11-01-84 ____ full ___ 18-01-84 14z ______ full - 6.7 d
17 ____ 08-01-58 ____ full ___ 05-01-58 20z ______ full + 3.1 d
18 ____ 15-02-89 ____ full ___ 20-02-89 16z ______ full - 5.2 d
19 ____ 28-01-02 ____ full ___ 28-01-02 23z ______ full - 0.7 d
20 ____ 04-09-83 ____ new ___07-09-83 03z ______new - 2.5 d
21 ____ 26-02-61 ____ full ___ 02-03-61 14z ______ full - 3.6 d
24 ____ 17-03-68 ____ full ___ 14-03-68 19z ______ full + 3.0 d
25 ____ 02-01-84 ____ new ___03-01-84 05z ______new - 0.3 d
26 ____ 04-01-99 ____ full ____02-01-99 03z ______full + 2.4 d
27 ____ 31-01-83 ____ full ___ 28-01-83 23z ______ full +3.0 d
29 ____ 15-01-93 ____ new ___22-01-93 13z ______new - 7.5 d
__ 30 __17-01-93 ____ new ___22-01-93 13z ______new - 5.4 d
__ 39 __21-01-93 ____ new ___22-01-93 13z ______new - 0.8 d
__ 40 __23-01-93 ____ new ___22-01-93 13z ______new + 1.2 d
31 ____ 27-10-59 ____ new ___31-10-59 23z ______new - 4.2 d
32 ____ 27-01-61 ____ full ___ 31-01-61 19z ______ full - 4.2 d
33 ____ 03-03-72 ____ full ___ 29-02-72 03z ______ full + 3.7 d
34 ____ 05-12-72 ____ new ___05-12-72 20z ______new - 0.3 d
35 ____ 09-02-88 ____ full ____02-02-88 21z ______full + 6.7 d
36 ____ 15-12-62 ____ full ___ 11-12-62 09z ______ full + 4.5 d
41 ____ 27-01-94 ____ full ___ 27-01-94 13z ______ full - 0.3 d
42 ____ 03-02-94 ____ full ___ 27-01-94 13z ______ full + 7.2 d (new - 7.2 d)
43 ____ 24-02-97 ____ full ___ 22-02-97 10z ______ full + 2.0 d
44 ____ 09-11-98 ____ full ___ 04-11-98 05z ______ full + 5.3 d


Analysis

Having looked at the maps for all these events, they fall into two types, one is a westerly type of event where low pressure forms in the central Atlantic at a fairly high latitude and moves east, deepening at an opportune time for Malin Head to receive strong winds. The second type moves in from the southwest and often begins to deepen just as it passes Malin Head, in fact some of these cases looked very tame on the charts even at maximum gust time (4 Sept 83 may have been a gusty thunderstorm in a cold front, geostrophic winds appeared to be only 25-35 knots at peak). Some of these southwest cases were strong for a day or two before reaching Ireland, notably of course ex-Hurricane Debbie.

One exception to these sets was 27 Oct 59 which was essentially a northerly that developed from a slow-moving low. Peak winds were from 350 deg. Another exception was 3 Feb 94 which produced strong east-southeast winds (110 deg) ahead of a low moving slowly north near the west coast of Ireland. This was the only event in the list with peak winds between 360 deg and 190 deg moving through the eastern portion of the wind quadrants.

The maximum separation that any event could have from full or new moon is 8 days if it occurred at lunar apogee (when the average 14.8 day separation of full and new moon can be up to 16 days). One case was timed almost exactly between full and new moons as noted, several others were close.

The average separation was 3.7 days, which shows no significant attachment to full or new moon, or to the interval halfway between them. A further analysis showed no significant placement between full and new, as opposed to the other half of the lunar month (between new and full). There is some tendency for the storms to be closer to a full moon than a new moon (24 vs 14). See the later discussion of lunar declination for the probable reason.

As this could still not uncover cycles of 2-4 days in the placement relative to full and new moon, the following frequency counter was employed to study distribution:

freq
3........................@.@............................@.@.@.................@
2..............@........X.X...............@............X.X.X.......@.........X .........@......@
1..@.-.@.-.X.@.@.X.X...............X..-..@..@.X.X.X.......X.@......X..@.@.X..@..X
0_______________________________________________________________
...-7-6-5-4-3-2-1 n +1+2+3+4+5+6+7 -7-6-5-4-3-2-1 F +1+2+3+4+5+6+7

days before ... . new ... days after .. ... ... days before .. full .. days after

_________________________________________________________________

This analysis is fairly random in scatter but there is a significant cluster between 6 and 4 days before full moon. There is an equally apparent lack of cases around 2 to 4 days after new moon.

Those clusters may be more linked to lunar declination since quite a few storms in the list are in January and February, months when northern declination maximum is about 3 days before full moon by end of January and 6 days by end of February.

A count of declination dates on the 27-day cycle follows.

freq
3................................................................................ @........@
2......... @..@.@...... @.............................................@. @.@.....X...........@..@
1...@.--.X.-.X.X.@.@.X..X..X..X...X..X..--.--.X.@.@.@.X.X..X..X..X..@..@..@.X..X...
0________________________________________________________________
...-7-6-5-4-3-2-1 S +1+2+3+4+5+6+7 -7 -6-5 -4-3-2 -1 N +1+2+3+4+5+6+7

days before .... .. S Max days after .. ... ... days before .. N Max .. days after
_________________________________________________________________

This distribution is less random, there are more cases clustered around the northern declination maximum than elsewhere. So this declination cycle seems more connected to the storminess over the Atlantic than the full-new cycle.

One final analysis to show how many of the 38 cases fell in each month of the year:

TOTAL __ all __ top 10 __ 11-20 __ 21-38 (amended list)

SEP ____ 02 ___ 1 _______ 1 ______ 0
OCT ____ 01 ___0 _______ 0 ______ 1
NOV ____ 02 ___1 _______ 0 ______ 1
DEC ____ 04 ___1 _______ 1 ______ 2
JAN ____ 19 ___ 4 _______ 6 ______ 9
FEB ____ 06 ___ 1 _______ 2 ______ 3
MAR ____ 04 ___2 _______ 0 ______ 2

April to August failed to make the list although I can remember one storm in May that must have been fairly close.

I think most of us would have guessed January as the most frequent month but its dominance is somewhat surprising, half of these top 38 windstorms at Malin Head fell in January. It appears from the data that mid to late January are especially favoured and this begins to peter out in early February.

Three historical storms of interest, no idea what peak gusts were at Malin Head, but the 6-7 Jan 1839 "Great Wind" event occurred about seven days after a full moon early 31 Dec 1838, and thus was about seven days before a southern max. So that one despite its ferocity does not really fit the profile of many January storms near full moon - northern max. ... The noted storm of 8 Dec 1886 took place about three days before a full moon 11th Dec 0930z. That would have been about four days before the slightly later northern maximum (these run from 4 days after full moon in early Nov to 2 days before in early Dec, overlap around 22 Dec, then fall earlier moving forward into January, about 3 days before full moon by mid-January and 6 days by late February.) ... the damaging windstorm of 27 February 1903 was raging at a new moon (27 Feb 1020z).

For my research, the main point to be investigated is how this declination cycle interacts with various weather patterns, for example, if it's a cold blocking pattern, the high pressure areas tend to reach greater central pressures towards full moon and northern max dates, if it's a fast westerly pattern you can pretty much count on a deep low, and if it's a mild southwesterly, a particularly mild warm sector around that time. As there are similar effects in other zones around the hemisphere, I am working on the theory that the whole pattern is a large-scale interference pattern that replaces the ocean tides where the same energy is dissipated on coastlines -- as the atmosphere has only partial boundaries and no hard edges, this energy must be always on the move, but I think it does peak in defined zones and some day I hope to show more of the evidence for that, but not in this post.

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RobertKK Registered User
#18

The two weather events my father always talks about are the snow of 1947 and the January storm of 1974.
We are on a hill exposed to the southwest, west and northwest. He said he had to go out to some cattle in a field and also make sure the reek of hay was secure. That one would hear the gusts of wind coming and he would have to get down close to the ground given it's strength as you couldn't stay on your feet if you kept upright.

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weisses Registered User
#19

Wind at Dingle harbor was recorded at over 180 kph during Darwin ... never found that number online though

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M.T. Cranium Registered User
#20

Darwin was fairly close to being at the northern declination maximum, as you know the date of the storm was 12th Feb 2014 and a full moon occurred 14th Feb 2354z which I would place at 2.5 d after the storm's peak, northern declination max was on the 10th.

These pressure tendencies show up in the long-term data that I acquired but I have been trying to separate out cases to get some clearer indications of what is happening.

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