Saturday, February 10, 2024

January 5-12 2024 Severe Weather Review

February 10, 2024

I don't really have the time that this event really deserves to do it justice but I'll do my best. In early January there were signals in the mid-range models that a rather potent stormy pattern was shaping up including the potential for significant impacts from severe weather. Many of the storm tracks in the fall and so far this winter have been along the coastal areas (I think influenced by El Nino's impact to the position of the subtropical jet stream) versus the more northerly route most seem to take for a "typical" winter. Right after the new year we were treated to a rapid succession of four storm systems. The first had no severe weather associated with it. The next two became progressively more severe and then the forth was more tame thankfully.


For all three system there were a total of 28 hail reports, 581 (yes, 581!) wind reports, and 44 tornado reports (also an astonishing number!). Some of these were not in our immediate area but the majority were. Day 1 Convective Outlook verification maps for each of the three events are below. I'm using the 1200 Zulu Time verification maps but frequently the forecasts are adjusted throughout the day which can provide a different look to how well each forecast did. Note also that each "day" runs from 1200 Zulu on the day it is issued until 1200 Zulu the next day. So storm reports before 6 a.m. the next day fall on the previous day's report. Because of this many of the reports shown on the January 8 map actually occurred early on the morning of the 9th. An archive of detailed information for storm reports can be found here. The Convective Outlook Archive (including verification maps) can be found here.


January 5th


January 8th


January 9th


January 12th


Subjectively, just looking at the storm reports plotted on the Day 1 forecasts I would say that the forecasts for the 8th and 9th were very good but that the forecasts for the 5th and 12th were somewhat incorrect. This may be an unfair judgement for the forecast on the 5th as Marginal events can be right on the edge of producing severe storms and there were some reports on the eastern boundary of the risk area. I like to see reports sort of evenly spaced across the risk area. In truth and as you can see severe weather events tend to cluster. There is often uncertainty in the evolution of conditions needed for severe weather to occur in both time and space and the risk areas may be drawn with this uncertainty in mind. For January 5th severe weather did occur more or less at the frequency expected it just occurred a little later in the forecast period and thus the reports are clustered in the eastern portion of the risk area. 

You can see something similar for January 12th. The SPC nailed the Enhanced area, but notice there were no reports at all over the rest of the Slight risk area. There are two more interesting bits about the forecast on the 12th. One is that the Day 2 forecast for the 12th looked quite a bit different than the Day 1 Verification shown above. For reference, see my post from January 11th here. The other is that there were no tornado or hail reports, despite each having a 5% chance of occurring. A 5% chance doesn't sound very high, but that is defined as a 5% chance within 25 miles of any point in the forecasted risk area. Given such a large area that this forecast covered I would have expected a few reports from each of these threats but they didn't materialize. There are always good reasons why a forecast doesn't pan out and I haven't taken the time for the event this day to learn why it didn't. It's also worth noting that if severe weather occurs in an uninhabited area it could very well go unreported so the absence of reports doesn't always mean severe weather didn't occur.

Now for the main event on the 8th and 9th. This event was very well forecasted. There was a lot of press leading up to this event at least two or three days in advance and I hope people heeded that and that lives were saved because of it. Many people that are regular readers were either directly impacted by these storms or know somebody that was. This was the most significant severe weather event (not counting tropical impacts) along this part of the coast that I can remember. The Mobile, AL NWS office documented damage from 9 different tornadoes and the Tallahassee office documented damage from 14 tornadoes. You can get more details on these reports here for Mobile and here for Tallahassee.

The most noteworthy report was the EF3 tornado that hit Panama City Beach causing significant damage to many structures. This same storm continued across St. Andrews Bay causing EF1 damage in Panama City before reintensifying into an EF2 as it moved through the Lynn Haven and Deer Point Lake areas. An EF0 "satellite" tornado from the same storm also cause some minor damage on the beach. four other EF2 tornadoes were reported by the Tallahassee NWS office. Thankfully the tornadoes in the Mobile and Pensacola area weren't as strong although quite a bit of damage still occurred.

There are a lot of details I left out but the links above should provide more info if you're interested. Hopefully we won't see a severe weather like this again for a while.

Chris

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