Neurons in the hippocampus exhibit striking selectivity for specific combinations of sensory features, forming representations which are thought to subserve episodic memory. Even during a completely novel experience, ensembles of hippocampal ``place cells'' are rapidly configured such that the population sparsely encodes visited locations, stabilizing within minutes of the first exposure to a new environment. What cellular mechanisms enable this fast encoding of experience? Recent work has implicated a novel “behavioral-timescale” synaptic plasticity (BTSP) rule in hippocampal area CA1 which can rapidly modify neuronal tuning, but it remains unclear how ubiquitous this mechanism is during novel learning. We leveraged virtual reality and large scale neural recordings to dissect how novelty and experience affect the dynamics of place field formation. We show that the place fields of many CA1 neurons transiently shift locations and modulate the amplitude of their activity immediately after place field formation, rapid changes in tuning that are predicted by BTSP. Place fields exhibited firing motifs consistent with underlying plateau potentials and somatic burst spiking, and these signatures were particularly enriched during initial exploration of a novel context and decayed with experience. Our data indicate that novelty modulates the effective learning rate in CA1, favoring burst-driven field formation to support fast synaptic updating during new experience. To probe the mechanisms underlying these transient representational changes, we also recorded calcium dynamics from axonal projections of the locus coeruleus (LC) as they terminate in CA1, using the same context switching paradigm. Exposure to the novel environment briefly altered the pattern of LC activation, congruent with the hypothesis that broader novelty detection circuits may open a temporary window of heightened plasticity via adjusting neuromodulatory tone. In CA1, we suggest one consequence of this may be to transiently increase the probability of plateau potentials, which could upregulate BTSP during novel experiences.