Why the dollar-yen rally will fizzle soon

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The U.S. dollar rose to its highest level against the Japanese yen since August 2008 on Wednesday, but analysts don't expect the rally to last.

"The pace has come so far and so quickly that I am inclined to think it's really due for a little bit of a pullback or consolidation," Sean Callow, senior currency strategist at Westpac told CNBC.

Read MoreDollar-yen breaches 110 for first time since 2008

The dollar-yen reached 110.08 in Asian trading Wednesday and has risen 8 percent since early August, driven by expectations for a Federal Reserve rate hike in the first half of 2015 and weak readings on the Japanese economy.

Mr Yen: Japanese currency won't fall beyond 112
Mr Yen: Currency won't fall beyond 112   

Poor household spending and industrial production figures released this week highlight the continued drag that a three-percentage-point consumption tax hike in April is having on the economy. Household spending fell 4.7 percent on year in August, while industrial production declined 1.5 percent.

Be careful what you wish for

The fresh dollar-yen high prompted Japan's Deputy Chief Cabinet Secretary, Katsunobu Kato, to call for authorities to monitor yen weakness closely because of its impact on prices.

Concerns that excessive yen weakness could make it difficult for corporations to purchase materials abroad underlie Kato's call, a departure from recent rhetoric on the yen. Japanese policymakers have called for a weaker yen to support the economy by boosting exports since Shizno Abe commenced his effort to jump start the economy last year. Bank of Japan Governor Haruhiko Kuroda dismissed concerns about yen weakness as recently as mid-September.

Read MoreYen's drop—too far, too fast?

"You would be brave to call a top right here, but on a multi-week basis we are hearing a little bit more about the negatives of a weaker currency from officials and industry groups who are a bit startled by the pace of the decline," Callow said. He expects the pair to retreat to 105 by year-end.

"As we get towards the 110 level we should see more comments from officials trying to calm the mood," said Greg Gibbs, senior currency strategist at RBS.

The dollar-yen previously faced technical resistance between 110 and 112, which could limit potential upside, Gibbs added.

Read MoreMrs. Watanabe jumps on yen-selling bandwagon as tide turns

"It's not the right time to buy," he said. "I'd recommend lightening up long positions and thinking about a possible tracing back to 107."

Sky's the limit

Richard Yetsenga, head of global markets research at ANZ, disagrees.

"The U.S.dollar looks very strong across a broad front, so certainly we might get some stabilization around 110 but there are no signs of a pullback at this stage," he said.

"The more the market worries about China, and the closer we get to the Fed hiking, both of those forces are going to add impetus to dollar-yen moving higher," he added.

On Thursday, the dollar yen was trading at 108.95.