Products and Services for Disaster Mitigation and Economic Enhancement Edward O’Lenic, Chief Climate Operations Branch NOAA-NWS-Climate Prediction Center Camp Springs, Maryland , ext 7528 NWS Products Users Workshop Thursday, August 9, 2001 National Weather Service Headquarters Silver Spring, Maryland

Mission

WEATHER vs. CLIMATE

El Nino Global Impacts

La Nina Global Impacts

Monthly and Multi-Seasonal Outlooks Temperature

Monthly and Multi-Seasonal Outlooks Precipitation

Probability of Exceedance: June – August 2001 Cooling Degree Days in U. S. Climate Region 45 (western Kansas)

Extended Range Outlooks Outlooks for average temperature and precipitation for 6-10-, 8-14-days

Degree Day Assessment The CPC weekly Degree Day Assessment discusses the Heating Degree Day (HDD) or Cooling Degree Day (CDD) outlook for the coming week, and reviews temperature and degree day statistics for the past week and the heating season (November - March) or cooling season (May - September) to date. This Assessment can assist energy managers in anticipating and analyzing fuel demand, because degree days quantitatively reflect the public need for energy to heat and cool businesses and dwellings. The Last 2000/01 heating season discussion, issued March 19, 2001, indicated that the slow seasonal decline in HDD’s should generally continue March 19 – 25, with increases in 7-day totals (relative to last week) restricted to the Southeast, northern Gulf Coast, and middle Ohio Valley. Temperatures should average below normal from central and southern Texas eastward and northeastward through the south Atlantic, central Appalachian, and southern mid-Atlantic regions. In contrast, above-normal temperatures should prevail for most areas from the High Plains to the West Coast, except for most of Washington and Oregon. However, HDD totals should generally be within 60 of normal nationally, except in the northwestern Great Basin, where totals are expected to be 60 to 90 below normal.

Uses of Climate Outlooks

Linking Climate and Weather

A preliminary example of the multi-level infrastructure envisioned for the next generation of climate services 8Provides weekly status of ongoing drought conditions 8Consolidates information from numerous federal and state agencies 8Combines several key drought indices (Palmer, soil moisture, precipitation on several time scales, etc.) with subjective input from local and regional experts 8Serves as a universal starting point for information access, from which users can delve into more detail Drought Status

Drought Outlook

PROBABILITY OF A HEAT WAVE MAXIMUM HEAT INDEX Heat Wave / Heat Index Outlooks

ENSO Diagnostics March 12, 2001 Discussion Mature cold episode (La Niña) conditions continued during February 2001, as sea surface temperatures (SSTs) remained more than 1.0°C below average across portions of the central equatorial Pacific between 160°E and 160°W (Fig. 1). Since early February 2001, SSTs have become anomalously warm in many sections of the eastern tropical Pacific (Fig. 2). Similar features were observed at about the same time of the year in both 1999 and 2000 (Fig. 3). In both of those years the anomalous warming of the eastern equatorial Pacific SSTs lasted until May and then rapidly disappeared as cross-equatorial flow from the Southern Hemisphere into the Northern Hemisphere became established and seasonal rainfall began to increase over Central America, southern Mexico and the southeastern tropical North Pacific.Fig. 1Fig. 2Fig. 3 Since the demise of the El Niño, many ENSO indices have shown distinct annual cycles, with the northern winter seasons featuring 1) minima in the SST, 2) maxima in the OLR anomalies, and 3) maxima in the low-level easterly winds over the central equatorial Pacific. The slope of the oceanic thermocline has been greater than normal throughout this period, with positive (negative) subsurface temperature anomalies in the west-central (eastern) equatorial Pacific. The strength of this anomalous subsurface pattern has also displayed an annual cycle since mid The evolution of the atmospheric and oceanic anomaly patterns since mid-1998 is similar to, but stronger than, that observed during , which followed the strong El Niño. During both of these post-strong El Niño periods the anomalous annual cycles were accompanied by an enhanced Australasian monsoon system. Over the past two years there has been a gradual expansion of the area of positive equatorial subsurface temperature anomalies into the central Pacific. This evolution is consistent with a slow decay of the subsurface thermal structure that characterizes the mature phase of cold episodes. Thus, it is likely that cold episode conditions will gradually weaken over the next several months, with near-normal conditions likely during the summer of This assessment is generally supported by the most recent NCEP statistical and coupled model forecasts, as well as by other available coupled model and statistical model predictions, which indicate a gradual weakening of cold episode conditions during the next few months. Thereafter, the models indicate near- normal or slightly warmer-than-normal conditions during the second half of Weekly updates for SST, 850-hPa wind, OLR and the equatorial subsurface temperature structure are available on the Climate Prediction Center homepage at: (Weekly Update). Forecasts for the evolution of El Niño/La Niña are updated monthly in CPC's Climate Diagnostics Bulletin Forecast Forum. This ENSO Diagnostic Discussion, which replaces the ENSO Advisories, will appear regularly around the 10 th of each month on the CPC web site.Weekly UpdateForecast Forum