03 Executive Summary

Weather and Climate Inventory, Klamath Network, National Park Service, 2007

Executive Summary

Climate is a dominant factor driving the physical and ecologic processes affecting the Klamath Inventory and Monitoring Network (KLMN). In coastal park units like Redwood National and State Parks (REDW), ecological characteristics are very dependent on the frequency and length of time a given site is under the influence of maritime air, including maritime stratus and fogs, a vital moisture source for coastal park units. In interior park units, conditions are drier with much more temperature variability. Snowfall is a significant water source for interior park units like Crater Lake National Park (CRLA) and Lassen Volcanic National Park (LAVO). Summer thunderstorms can ignite fires in late summer and fall. Future climate change may have significant impacts for the KLMN such as possible decreases in winter snowpack, shifts in species distributions, and the potential loss of winter freezing temperatures. Because of its influence on the ecology of KLMN park units, climate was identified as a high-priority vital sign for KLMN and is one of the 12 basic inventories to be completed for all National Park Service (NPS) Inventory and Monitoring Program (I&M) networks.

This project was initiated to inventory past and present climate monitoring efforts in the KLMN. In this report, we provide the following information:

• Overview of broad-scale climatic factors and zones important to KLMN park units.

• Inventory of weather and climate station locations in and near KLMN park units relevant to the NPS I&M Program.

• Results of an inventory of metadata on each weather station, including affiliations for weather-monitoring networks, types of measurements recorded at these stations, and information about the actual measurements (length of record, etc.).

• Initial evaluation of the adequacy of coverage for existing weather stations and recommendations for improvements in monitoring weather and climate.

The climate of the KLMN is generally typified by cool, wet winters and warm, dry summers. In winter, strong prevailing westerlies bring frequent storms. Extremely rugged topography and proximity to the Pacific Ocean work together to create exceptionally severe climatic gradients in KLMN park units. Mean annual precipitation in the KLMN ranges from under 500 mm at Lava Beds National Monument (LABE) to over 3000 mm at the higher elevations of LAVO. Mean annual temperatures range from under 3°C in portions of CRLA to over 15°C at lower elevations of Whiskeytown National Recreation Area (WHIS). Winter temperatures are generally mildest near the coast, where minimum temperatures rarely get below freezing. In summer, the subtropical Pacific high-pressure system strengthens and the prevailing westerlies weaken and move northward. Summer daytime temperatures struggle to get above 15°C near the coast but easily exceed 35°C in some interior park units like WHIS. Summer precipitation is usually associated with weak frontal disturbances and occasional thundershowers. The El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Pacific-North America Oscillation (PNA) all influence intra- and inter-annual climate variability in the KLMN.

Through a search of national databases and inquiries to NPS staff, we have identified 32 weather and climate stations within KLMN park units. Crater Lake National Park has the most stations within park boundaries (10). Most of the weather and climate stations identified for KLMN park units had metadata and data records that are sufficiently complete and satisfactory in quality.

The primary source of automated weather data for these park units generally comes from RAWS (Remote Automated Weather Station) or SNOTEL (Snowfall Telemetry Network) sites. It is therefore beneficial for climate monitoring efforts in the KLMN that the NPS work closely with local agencies to continue the operation of existing RAWS and SNOTEL stations within KLMN park units, as well as to encourage the addition of new stations.

New stations would likely be beneficial in places such as the north rim of Crater Lake, where there are currently no automated weather stations. Despite the storied history of heavy snowfalls at CRLA, snowfall patterns in the park unit are severely undersampled. Only one station, a NWAVAL (Northwest Weather and Avalanche Center network) station near Rim Village, provides observations of near-real-time snowfall and snow depth. Therefore, it may be useful to partner with NRCS to convert one of the existing snowcourse sites near Rim Village into a SNOTEL station, providing additional near-real-time snowfall data for the park unit and providing another data point to compare snowfall patterns with other SNOTEL stations around CRLA.

Additional areas lacking in automated weather station coverage include northern LABE as well as southern and eastern portions of LAVO. The RAWS network already has a strong presence in these areas, so NPS may want to consider working with local agencies to install a RAWS station. SNOTEL installations could be considered as well for locations that receive substantial snowfall.

The only station we identified within Oregon Caves National Monument (ORCA) is a Citizen Weather Observer Program (CWOP) station. Although this is a real-time station, siting standards for the CWOP network are generally not well-defined and the reliability of CWOP data records is sometimes questionable. Therefore, ORCA may want to consider working with local agencies to install a RAWS site within the park unit. The RAWS network does have well-known standards for station siting and this strategy would also improve the coverage of the RAWS network, which already has a significant presence in the area surrounding ORCA.

There are no automated stations devoted to weather/climate measurements within the central portions of REDW. In addition, weather/climate station coverage is nonexistent to the east of the central portion of REDW. The park unit may want to consider adding a RAWS station at the same location as the existing GPMP and NADP stations, near the mouth of the Klamath River. A RAWS station is a natural choice for such an installation due to the RAWS network’s already significant presence in the REDW area.

Most of the KLMN park units have at least one long-term climate station either within the park or within 40 km of the park unit. Climate monitoring efforts within the KLMN will benefit by encouraging the continued operation of those active stations having longer climate records, as these records provide valuable documentation of ongoing climate changes within KLMN park units.

 << previousnext >>