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  • Writer's pictureTim Donohue

[Thanksgiving 2021] Sunday Nov 21 update

Yesterday, we surveyed 12 airports in our first look at Sunday travel - today we're back to dive a little deeper on 5 airports. Just to make sure we're all on the same page, we're covering tomorrow, the 21st, in this update, which figures to be the second busiest "go" day of the Thanksgiving period (behind Wednesday); we'll cover return travel on Sunday, the 28th, in later outlooks.


Today's update will still be shaped largely by the same cold front we discussed in yesterday's first look. Importantly, progression of the cold front has slowed somewhat in the last day. Nonetheless, numerous showers are expected to break out from the Deep South to the Northern Mid Atlantic on Sunday afternoon ahead of the front; coverage of showers expands to the Northeast and Southeast by Sunday evening.


With the number of airports included in today's outlook right-sized, we'll move through it from West to East (rather than alphabetically). That also allows us to start with what is probably the most interesting case: Dallas-Fort Worth (DFW). While a dry frontal passage is forecast for the DFW area, winds will shift to the north behind the front. Unfortunately, the wind shift is not sudden and instead winds spend much of the morning veering from south to north. The good news is wind speeds don't really pick up until after the wind shift is complete and velocities for most the morning will be in the low (to perhaps mid) teens. Nevertheless, a westerly component to the wind - even relatively light - is problematic at DFW, which is optimized for the prevailing north-south wind. We'd put the chances at DFW's arrival rate dropping into the 60's or 70's at about 1 in 10; we estimate there's a 1 in 5 chance DFW delivers an arrival rate in the 80's. Either scenario will create a demand overage in the 9 a.m. hour, during which 100 flights are scheduled to arrive.


A 78 rate in the 9 a.m. hour creates about 1,800 total minutes of delay to be distributed across 100 arrivals - an average delay of 18 minutes would likely be enough to turn a 40 minute planned layover into a broken connection. We'd bet, however, that the FAA manages this demand overage with a ground stop, which would disproportionally distribute delays to those flights that originate from "nearby" airports (i.e. within 600 miles - to include PHX, MCI, STL, BNA, MEM, IAH). The last thing we'll mention related to DFW are the ceilings, which will be right on the edge of influencing the airport's capacity. If ceilings fill-in towards the lower end of forecast, we'd nudge up the probabilities for a reduced arrival rate (and thus bump of predicted delays as well).


Let's move over to Washington Reagan (DCA), where showers should hold off until evening. Even when rain starts, the refined weather forecast prompts us to raise our estimated arrival rate to between 30-32. This should accommodate [largely without delay] the 28 and 29 scheduled arrivals in the 7 p.m. and 9 p.m. hours, respectively.


If showers hold off at nearby Philadelphia (PHL) through the 6 p.m. hour - which they look to do so at the moment - passengers transiting PHL should escape without air traffic delays. While the 6 p.m. hour represents a demand peak (when 36 flights are scheduled to arrive), in the absence of rain, we're confident (19 in 20) that sufficient capacity will be available. If rain arrives earlier than forecast, we think a 32 arrival rate is a reasonable worst case scenario; in this case, arrival delays approach 35 minutes (and linger through the 7 p.m. hour).


Passengers transiting Newark (EWR) may not be totally unscathed, however this forecast has improved as well. We believe EWR should maintain a 40 arrival rate (better than 8 in 10) even once showers arrive in the evening. Unfortunately, scheduled demand equals 44 in the 7 p.m. hour (with little room for recovery in the 8 p.m. hour). Minor delays can be expected (i.e. no more than 10 minutes), though may be largely imperceptible (i.e. some circuitous descents, maybe very brief airborne holding). Imperceptible delays are no less real, however, and still eat away at valuable layover minutes.


We round out today's outlook with New York-LaGuardia (LGA). On the demand side, they look quite similar to PHL, with a peak of 36 scheduled arrivals in the 6 p.m. hour. Unfortunately, we're not quite as confident that sufficient capacity will be available (about 1 in 6 chance for an arrival rate between 30-33). We modeled a 30 arrival rate starting at 5:00 p.m., which produces average delays of about 20 minutes for the remainder of the day; given how delays knock on to later hours, average delays are actually highest for arrivals scheduled in the 9 p.m. hour (around 35 minutes).


Where does this leave readers traveling tomorrow? We're most concerned about about any trips that are starting in the South Central US and connect through DFW in the 9 a.m. hour. - if this sounds like your itinerary, we'd suggest you at least consider taking advantage of airlines' improved rebooking flexibility. We've linked to American's same-day change and standby policy. Passengers connecting in EWR during the evening may find their layovers compressed slightly, however we anticipate problems for only the shortest planned layovers (i.e. less than 40 minutes). If your evening layover in EWR is of the very short variety, we've linked to United's same-day change and standby policy. Across the river at LGA, we think adjusting delay expectations (less than 45 minutes in all likelihood) should do the trick, as comparatively fewer connections are made at LGA.


We're taking tomorrow off then will be back on Monday with a first look at Wednesday's "go" travel.

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