Titanic Anniversay: Weather on this day 100 years ago (11th April 1912)

At 11.30 am on the 11th April 1912, the Titanic dropped anchor in Cork Harbour to pick up the last of its passengers before setting sail for New York. What happend on that journey is well known to everyone, and something that has personally given me nightmares since I was a child. There has been bigger, but less known marine disasters before and after Titanic, one such being the HMS EMPRESS of IRELAND tragedy in 1914 but I guess what makes the Titanic disaster stand out was not only the colossal size of the liner but that it also sank on its maiden voyage.

The weather on this day 100 years ago was a typical fair weather spring day in Ireland, with light to moderate NW to N winds and temperature close to the seasonal norm. Max temperature at Phoenix park on this day was 10.0c with Newcastle (Galway) reporting max temp of 11.1c. From this, I would say the temperature at Cobh would have been around 9c-10c around the time that Titanic docked.

Scant reports say that the weather was fair but breezy as the Titanic departed Cork Harbour. Looking at photographs taken as Titanic both entered and departed Cork Harbour, it looks as if the dominant cloud type was broken stratocumulus (Sc) at around 5 or 6 octas.

The two photographs below show Titanic entering and departing Cork Harbour. I messed around with the contrast of both photos in PS to try and highlight the actual sky as much as possible:






MSLP chart showing pressure pattern around the time that the Titanic set off on its final journey. A reasonably slack gradient over Ireland in a stable NW to N air flow:


Image extracted from the NOAA-CIRES Twentieth Century Global Reanalysis (Version 2)

The actual pressure gradient suggest that the winds would have been light to moderate on this day over much of the country but possibly fresher in more exposed coastal areas hence the reports that the winds were 'brisk' during Titanic's brief stop off at Cobh.


Weather reports from Titanic's actual journey across the Atlantic are sparse and not very detailed but the general consensus is the weather remained fair both on the 12th and 13th April with lighter winds than was experience in Cork harbour - due in no small part to the ridge of high pressure on the chart above! - but with reports of some fog banks also.

Later on the 13th, or possibly early 14th, the Titanic ran into the path of a cold front which was moving west. What reports there was suggest that the winds picked up from the SW (no mention of by how much but unlikely to be very strong) and that it became too chilly for passengers to enjoy staying out on deck. Wave heights reportedly reached around 2.1 m during the passage of the front, which going by the synoptic charts, was probably not all that particularly active.

The weather cleared and it became colder with temperature dropping to as low as 29F (-1.6c) by nightfall according to some sources. The sheer calmness of the night was noted as being 'unusual' by both the captain of the ship and by its crew. This calmness was due to a strong ridge of high pressure that followed on from the cold front that had passed on earlier.

This anticyclone had its origins in the NW Canadian Arctic region which help to drag down a deeply cold pool of air on its eastern flank as it moved SE'wards into the Atlantic. This resulted in the vivid clear, starry skies that were were observed by both passengers and crew on the night of the tragedy, and also the intensely cold temperatures that unfortunately helped to increase the fatality count after the sinking.

Chart below shows the MSLP patten over the western Atlantic at the time the Titanic sank beneath the ocean:


Image extracted from the NOAA-CIRES Twentieth Century Global Reanalysis (Version 2)

Going by this chart what wind there was during Titanic's final moments was probably from a NW to N direction but as reported very light to calm as the ridge intensified over the region.

Just to note, there is some debate as to the actual time of Titanic's sinking. Popular belief is that it sank sometime around 2.20am but many have noted that this based on 'Titanic' time only. The clocks on the Titanic were adjusted on a daily basis in an attempt to keep in with the time-zone they were sailing through at a particular time and were not in accordance with GMT time. Going by this, it is quite likely (although not certain) that the Titanic sank closer to 5.40 am Irish Time.

This concept is much better explained here as I have been writing long-winded post this since 11.20am and am just about drained out. Can't believe it is 1 o clock already!

Edit: An nice old folk tune with Titanic theme : http://www.youtube.com/watch?v=FWo6qH7bCIA

Further reading:
Titanic Inquiry - Weather during voyage
The Unfinished Trip
Did weather sink the Titanic?
Titanic's last radio transmission