Story highlights Month-to-month numbers in apprehensions can be misleading

Still, Trump supporters are likely to see the numbers as vindication

Washington (CNN) Apprehensions at the southern border decreased sharply in January, according to statistics obtained by CNN -- a drop in line with yearly seasonal trends but that could give President Donald Trump an early talking point in his efforts to ramp up border security.

According to preliminary Customs and Border Protection numbers for January obtained by CNN but not yet released to the public, family unit apprehensions decreased by 42%, unaccompanied minors were down 39% and total apprehensions decreased by 27%.

Month-to-month numbers in apprehensions can be misleading. According to data for the past four years, apprehensions typically drop in January and did so sharply in 2016.

Next month's data could be critical in interpreting whether the drop was due to seasonal trends or something bigger. The amount of migration north through Mexico is also tied to the conditions in Central America, where many migrants are fleeing violence and drug cartels.

The numbers also do not take into account what are called inadmissables -- migrants who present themselves at the border and are deemed unable to enter the country, often due to lack of authorization. Apprehensions refer to those removable aliens who are arrested.

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