Friday, Aug. 12 & Saturday, Aug. 13 Outlook

Monsoonal rains continue for Southwest and Rockies; meager moisture marginally supports thunderstorm development around ORD on Saturday

Welcome to any new readers! And as a reminder to long-ish time readers, we’re testing a new format for these outlooks. To both old and new—we’re grateful you’re here.

If you have questions about the content of this outlook, the answers might be in this post. Otherwise, let us know if something doesn’t make sense (we welcome feedback of all kinds!).

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Friday, August 12

We forecast TSA will screen 2.384 million travelers (± 0.5σ, or a prediction interval of about 38%, is 2.32-2.45 million travelers).

Monsoonal storms continue for portions of the Southwest and Rockies. The cold front that tracked through the Northeast yesterday has become quasi-stationary across the Tennessee and Mississippi Valleys. As the front slowly sags south, a very moist pre-frontal airmass will support multiple rounds of showers and thunderstorms. By late Friday, a secondary cold front will begin to sweep out the stalled boundary.

42% chance for an arrival demand overage during at least one hour at DEN on Friday; 2 hours during Friday at DEN where we estimate an arrival demand overage is more likely than not.

Friday likely won’t prove to be the best use case for this new automation, as we’re concerned about LAS, PHX and IAH [which fall outside its scope]. Additionally, the 100% probability for EWR is overdone: airlines are allowed to schedule more flights (in this case, 42 and 45 in the 2p and 3p hours, respectively) than the airport’s “normal” arrival capacity (40 aircraft per hour), though the airport can flex-up to a 48-rate (which this rudimentary model generally misses). If you’re wondering why more arrivals can be scheduled than the airport’s default capacity, so are we.

Saturday, August 13

We forecast TSA will screen 2.154 million travelers (± 0.5σ, or a prediction interval of about 38%, is 2.09-2.22 million travelers).

On Saturday, our attention will shift to the Midwest, where a disturbance attempts to wrestle some control from an elongated area of high pressure. More favorable dynamics for rain/thunderstorm development look to be northeast of ORD, though the forecaster maintains a slight chance for thunder.

You can check out hourly estimates in this workbook.