INTRAMONTHLY INDEXES OF THE PACIFIC NORTH-AMERICAN TELECONNECTION PATTERN AND TEMPERATURE REGIMES OVER THE UNITED-STATES

Previous work has examined relationships between the planetary scale P acific North American (PNA) teleconnection pattern and regional scale mean temperature over portions of the United States, but analyses have been restricted to monthly values of these two variables. It is not c lear if this is the most appropriate scale for relating PNA patterns t o temperature. In this study, PNA indices are related to various aspec ts of temperature over a range of time scales spanning one month. To c arry this out, standardized PNA indices are calculated for 6 time inte rvals ranging from 5 to 30 days over a period of 27 winter seasons. St andardized regional scale temperature anomalies are assessed over vari ous regions of the United States and used to compute mean, maximum, an d minimum temperature anomalies over the same 6 time intervals. Correl ation matrices are then constructed to provide relationship characteri stics between the PNA indices and temperature measures within the intr amonthly time scale. Only the southeastern and northwestern regions of the United States display significant relationships between the PNA i ndices and temperature. Over the Southeast, temperature anomalies on s hort time scales relate most strongly to PNA indices computed over tim e intervals of 25 to 30 days; this is especially the case for the mini mum temperature anomaly. The strongest relationships, however, are obs erved between the PNA index and temperature anomalies computed on a 20 -25 day time interval. Over the Northwest, the relationships are not a s strong and somewhat more varied. Most notably, moderate connections are found between the 30 day PNA index and minimum temperature anomali es computed over a 25 day period.