Streets are now rivers as floodwaters continue to rise in multiple counties across Texas in the aftermath of Hurricane Harvey.

UPDATE: Houston’s two busy airports will resume limited operations at 4 p.m. local time, the airports’ operating agency announced Wednesday afternoon.

Though flights will resume at both Bush Intercontinental and Hobby airports, officials said service would return gradually. 

“The Houston Airports plans to resume limited domestic airline passenger service TODAY at 4 p.m. following severe weather caused by Hurricane Harvey. We will attempt to begin a phased return to service, with full service expected by this weekend,” Houston airports said in a post on its Facebook page

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The airports also warned customers not to come to the airports unless they had confirmed the status of their flights. 

“Only those with a ticket for a confirmed scheduled flight should come to the airport,” Houston Airports said. “Many roads around the City of Houston are still unsafe for travel, therefore, we urge all passengers to take their time arriving to the airports and to solidify a safe route to and/or from our facilities.”

Still, the resumption of even limited service at Bush Intercontinental and Hobby represent the first glimmer of hope in stemming a massive wave of flights cancellations caused by Harvey. 

Nearly 10,000 flights have been canceled nationwide — and more than 8,700 in Houston alone — since the storm first began affecting flights on Friday. 

On Wednesday, more than 1,600 flights were canceled nationwide — nearly all to or from airports in Texas and Louisiana. And already for Thursday, more than 1,400 flights had been preemptively canceled and with another 617 already scrubbed from Friday’s schedules. 

This is a developing story. Check back for updates.

ORIGINAL POST: 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 sounded 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. Reports trickled in from filers who said they’ve already received cancellation alerts for flights on Saturday.As those numbers inched up Wednesday — Friday’s cancellations ballooned to more than 310 by 11:45 a.m. ET — they added to a whopping tally of cancellations since Harvey first began affecting flights on Friday. Since then, more than 9,600 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 9,600 (and counting) cancellations, about 8,700 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. New Orleans, for example, had begun to see rising cancellation numbers on Wednesday, adding to the overall totals. 

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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 the 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…