The weather in the northeast has been a rollercoaster of warm days with a couple of arctic blasts thrown in to keep things interesting. An unusually harsh winter slammed January and February auto sales throughout most of the country, and the rebound was expected to begin in March. But the ongoing cold has kept many buyers out of dealer showrooms. Analysts at Kelley Blue Book predict a SAAR of about 15.6 million vehicles nationally once March sales are fully reported. In order to reach their prediction of 16.3 million vehicles for all of 2014, that number would need to be closer to a SAAR of 16 million in March.J.D. Power and Associates forecast a slightly higher SAAR of 15.8 million vehicles in March, but cut its year-end forecast to 16.1 million from its previous forecast of 16.2 million.Better weather should unleash pent-up demand and increase sales, but if it doesn’t, automakers may cut production and raise incentives to help dealers work off the higher-than-normal inventories.