40th Anniversary of the 10/3/1979 BDL Tornado

[weatherwiz]

I decided to post this now b/c I did it now. 

We are closing in one of the more historic weather events to impact southern New England; the 40th anniversary of the October 3, 1979 Windsor Locks, CT F4 tornado. When continuing with this post, we need to keep in mind the time period this event occurred and understand our knowledge of severe weather forecasting and tornadoes was nothing compared to what it is now. In fact, the Fajita scale was a brand new implement. The set-up which produced the tornado back then was probably not really as recognized as it would be today. Anyways, just wanted to add this disclaimer as the tone of the post will be geared towards the time period of the event. 

Meteorological Set-up:

In the days preceding October 3, 1979, a ridge was building across the western United States with a trough configured across the east. This troughing was only enhanced by a rather significant trough digging into the northern Plains on the morning of October 3. Within the initial trough was a vigorous piece of shortwave energy which dove southeast from the northern Plains and into the southern-tier of the Ohio Valley before lifting northeast towards New England. 

At the surface, a low pressure was tracking through western NY, however, a secondary low pressure developed across southeastern PA/NJ along a triple point. As the warm front lifted north through CT Wednesday morning, this advected a warm and moist airmass into the sate. the nearby warm front also enhanced low-level wind shear across the state:

During the early afternoon, reports indicate some sun broke out of the overcast yielding surface heating. Surface heating combined with the moist low-level airmass helped to boost instability values. during this time, a supercell t'storm developed south of Long Island having a northward trajectory towards central CT. As this storm tracked north there were funnel cloud reports over Long Island and southern CT. 

As this supercell t'storm tracked through the CT Valley, the Valley likely enhanced the degree of low-level wind shear. The combination of instability/wind shear was just enough to yield a large and violent tornado which touched down around 3:00 PM EDT. While short-lived, the tornado caused significant destruction to Bradley Airfield, commercial businesses, as well as residential properties. In total 3 people were killed (initial reports feared perhaps hundreds may be dead) with several-hundred others wounded. At one point, this tornado was the 6th most costliest in U.S. history and caused $200 million in damage (1979 USD) ($690 million in 2019 USD (**these statistics gathered from wikipedia**). This was the deadliest CT tornado since the Great Wallingford tornado of 1878.

At the time of this tornado, this was the 4th October tornado in the state of CT since records began. It also happened to be the last October tornado until 2018 when two tornadoes were confirmed in what was a historic year for CT. This was the first tornado rated F4 (it is speculated the 1878 tornado was at least this strength) and there were even arguments by some this could have been rated F5 based on the fact some structures were completely wiped off their foundations. 

Thoughts on the event:

It is pretty remarkable such a setup was able to produce. It's a shame more weather data isn't available from then. Despite a lack of EML, there must have been some pretty vigorous 0-3km CAPE in place which resulted from breaks of sunshine yielding strong sfc heating. I forget the reports but I think temperatures may have spiked into at least the upper 70's...maybe even just above 80? Just looking at the upper-air pattern, however, wind shear certainly was supportive for rotating updrafts. The state was also in perfect positioning with respect to the triple point with the triple point passing right over the state. Such an event is so rare, but it shows what can transpire when all ingredients come together...the rarity of such an event also shows how difficult it is for this to happen. 

[Torch Tiger]

Definitely one of the more anomalous setups you'll see.

Any radar/sat shots?

[STILL N OF PIKE]

Cell traveled North from Long Island to BDL. Cool 

[Torch Tiger]

[Cyclone-68]

My only memory of that day was a tremendous thunderstorm walking home from school in Dedham MA and then hearing about the tornado on WBZ TV channel 4 

[weatherwiz]

16 hours ago, Dr. Dews said:

Definitely one of the more anomalous setups you'll see.

Any radar/sat shots?

I wonder if there are any radar images floating out there...at least radar. I think BDL may have had radar at the time. 

Anyways, from also reading on the write-up from wiki there was no tornado warning issued on the cell b/c the actual height of the storm was completely undermeasured. A severe warning was issued just minutes before the tornado, however, nobody received the warning. 

Based on the accounts and damage photos it's a miracle only three were killed.

16 hours ago, STILL N OF PIKE said:

Cell traveled North from Long Island to BDL. Cool 

It was a left-moving supercell. Oddly...the Ha,den, CT F4 in 1989 was also a left-moving supercell.