We already knew the economy really struggled over the first few months of 2015, with March being especially rough. A new report from economists at Macroeconomic Advisers shows just how bad a month it really was.

The forecasting firm, which tracks economic progress on a monthly basis rather than just a quarterly one, now says that GDP fell 1 percent in March. “This was the largest decline since December 2008, when the U.S. economy was in the throes of recession,” its update notes.

The Commerce Department initially estimated that GDP grew at a seasonally adjusted annual rate of 0.2 percent in the first quarter. An updated report, due May 29, is now expected to show that the economy actually shrank over the first three months of the year. J.P. Morgan economists have lowered their tracking estimate of first-quarter GDP from -0.8 percent to -1.1 percent based on data released over the last two days.

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As we’ve written before, though, the downturn isn’t necessarily reason to worry about the fundamental health of the economy, or at least it shouldn’t stoke fears that we’re diving into another recession. As the Macroeconomic Advisers report explains, “A sharp decline in net exports more than accounted for the decline in monthly GDP, as resolution to the West Coast port dispute led to a surge in imports to well above the recent trend. As a result, they write, they believe the one-month plunge “overstates the underlying weakness in the economy.”

That’s not to say the economy is particularly strong, either. Both Macroeconomic Advisers and J.P. Morgan now forecast second-quarter GDP growth to come in at a tepid 2 percent annualized rate.