Houston’s airports remained closed for yet another day. Flight cancellations continued to pile up at airports across Texas and Louisiana. And airlines kept extending change-fee waivers for airports along the Gulf Coast.

Wednesday’s flight forecast read like a broken record as the remnants of Hurricane Harvey continued a slow-but-devastating slog across the region.

Preemptive cancellations were again the rule of the day for air travelers on Wednesday. More than 1,500 flights were scrubbed well before midnight on Tuesday, according to flight-tracking service FlightAware. Another 1,300 flights had already been grounded for Thursday and another 75 for Friday. 

FLIGHT TRACKER: Is your flight on time? | UPDATED LISTAirlines waive change fees for Hurricane Harvey

Those figures were likely to keep inching up Wednesday, adding to a whopping tally of cancellations that began since Harvey first began affecting flights on Friday. Since then, nearly 9,400 flights have been canceled across the nation. Some have been from other causes, but the vast majority have stemmed out of complications from Harvey.

Of those 9,400 (and counting) cancellations, about 7,250 came just from the two Houston airports, FlightAware spokeswoman Sara Orsi said on Tuesday evening. Hundreds more have been canceled from other airports along the Gulf Coast because of Harvey during that span.

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Orsi said the number of flights axed by Harvey was higher than for most big storms, but that – so far- — the count was still well below number of flights canceled when “Superstorm Sandy” slammed the populous Northeast corridor in 2012.

“Typically we’ll see one or two big storms a year sweeping from Chicago to Boston that will yield around 5,000 cancellations each,” Orsi said in an e-mail to USA TODAY’s Today in the Sky blog. “Sandy was about 20,000.”

As for the preemptive cancellations on Wednesday and Thursday, the ongoing closure of Houston’s two busy airports bore the bulk of the blame; each had yet to reopen since Harvey forced their closures during the weekend.

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Even on Wednesday morning, it still wasn’t clear when flights might resume at Bush Intercontinental and Hobby airports. The airfields are key cogs in the U.S. aviation system. Bush Intercontinental is the second-busiest hub for United and is served by a long list of other domestic and foreign airlines. Hobby airport is one of the top airports for Southwest, the USA’s biggest low-cost carrier.

A number of other airports in Texas – and now Louisiana – were experiencing disruptions from Harvey’s persistent presence.

At least one other Texas airport — the Jack Brooks Regional Airport near Beaumont – also remained closed Wednesday, struggling to reopening since closing during the weekend. Beaumont received more than a two foot of run just on Tuesday alone, adding to the woes there. 

For now, United, Southwest and most of the other airlines that fly from airports kept tweaking their flexible rebooking policies to account for unwelcome duration of Harvey’s stay. United moved on Tuesday to significantly lengthen its rebooking policy, giving customers at 15 airports until mid-November to complete their trips. That extended the previous rebooking period by nearly two months. Southwest also extended its policy, expanding its window of covered flights for Houston. (UPDATED LISTAirlines waive change fees for Hurricane Harvey)

In the meantime, United and Southwest reiterated warnings that customers should not yet attempt to come to either of the Houston airports, citing the dangerous flood conditions affecting roads and neighborhoods near each of the airfields.

The rebooking waivers for many carriers also began to expand to include airports in Louisiana, a development that comes as…