The Washington Post reports the number of migrants detained after entering the United States along the southern border was up sharply in February, possibly setting the stage this spring for the highest number of migrants seen crossing the border in a decade:

A group of 64 parents and children had waded through a shallow bend in the Rio Grande to turn themselves in to the agent on the U.S. side…

Groups like this arrived again and again in February, one of the coldest and busiest months along the southern border in years. U.S. authorities detained more than 70,000 migrants last month, according to preliminary figures, up from 58,000 in January. The majority were Central American parents with children who arrived, again, in unprecedented numbers…

“The numbers are staggering, and we’re incredibly worried that we will see another huge increase in March,” said a Homeland Security official who spoke on the condition of anonymity to discuss the unpublished figures.

Last year, the number of migrants crossing the border jumped 39% in March over February as the weather warmed and seasonal workers began joining the flow of economic migrants. If there is a similar jump this year it would mean more than 100,000 migrants detained this month (March) alone. That would be nearly 20% of the total number detained for all of FY18. Even at the present rate, we’re talking about more than 2,000 people a day. That works out to roughly two migrant caravans (approx. 7,000) per week.

The migrants from Central America represent a new pattern in which people mostly aren’t trying to sneak across the border but are simply coming across and immediately surrendering to authorities to claim asylum. It’s legal to claim asylum after crossing the border but those claims have to be adjudicated and that can take months. One reason so many people coming across the border now travel with children is that they’ve learned they are far more likely to be released if traveling with a child:

Across rural Guatemala, Martinez said, word has spread that those who travel with a child can expect to be released from U.S. custody. Smugglers were offering two-for-one pricing, knowing they just needed to deliver clients to the border — not across it — for an easy surrender to U.S. agents.

“If this continues, I don’t think there will be anyone left in Guatemala,” Martinez joked. The men from his village near the town of Chiquimula were all leaving, he said, bringing a child with them…

The problem, Homeland Security officials say, is that a growing portion of those who pass the initial screening never appear in court. They know asylum standards are tightening. Or, like Martinez, they have a prior deportation from the United States that all but disqualifies them from getting asylum.

Once released into the U.S. interior, some shed their monitoring bracelets and slip into the shadows to remain in the United States, a country where wages are 10 times higher than in Central America.

This “catch and release” system is exactly what the Trump administration is concerned about. It remains to be seen what percentage of this surge of migrants will follow the rules and what percentage will take advantage of the system and disappear. The Post makes the case that the border patrol is struggling to keep up. Its system was designed to turn away Mexicans sneaking across the border who could be deported quickly because they weren’t asylum seekers. Now that thousands are arriving daily with children and claiming asylum, the system is overloaded.

Here’s the Post’s video report on the group of 64 mentioned above who turned themselves in to seek asylum: