IntermtnClimateSummaryJan2006 - Laserfiche WebLink

Home Browse Search

INTERMOUNTAIN WEST CLIMATE SUMMARY, JANUARY 2006 Temperature Outlook January - May 2006 According to the outlook released Dee 15,2005 by the NOAA Climate Prediction Center, a large area of the U.S., including much of the Intermountain West, has an increased risk of above average temperatures in January 2006 (Figure 10a) and forecast periods through the spring of 2006 (Figures 10b-d). Much of Utah and Colorado are included through the March-May 2006 forecast period, and much of the region through summer forecast periods (not shown). Wyoming is not included in the area of increased risk of above average temperatures after Janurary 2006, because La Nina-like conditions elevate the chances for below normal temperatures in the northern tier of the U. S. This risk of cool temperatures largely counteracts the recent warming trends and brings temperature probabilities in these areas in line with 1971-2000 climatology. The CPC will update the seasonal temperature forecasts on Thursday, January 19th. This forecast utilizes a new forecast tool that should signifi- cantly improve temperature forecasts over the continental U.S, including the Intermountain West. The tool combines several statistical models and a 15-member ensemble mean from dynamic models using the known skill of the various tools to form a weighted average. This new tool helps to reduce the uncertainty which forecasters confront when they try to subjectively combine various forecast tools. Source: NOAA Climate Prediction Center Notes The seasonal temperature outlooks in Figures 10a-d predict the likelihood (chance) of above-average, near-average, and below- average temperature, but not the magnitude of such variation. The numbers on the maps refer to the percent chance that tempera- tures will be in one of these three categories, they do not refer to actual temperature values. The NOAA-CPC outlooks are a 3-category forecast based largely on the status of EI Nino and recent trends. As a start- ing point, the 1971-2000 climate record for each particular 1 or 3 month period is divided into 3 categories or terciles, each with a 33.30/0 chance of occurring. The middle tercile is considered the near-average (or normal) temperature range. The forecast indi- cates the likelihood of the temperature being in one of the warmer or cooler terciles--above-average (A) or below-average (B)--with a corresponding adjustment to the opposite category; the near-aver- age category is preserved at 33.30/0 likelihood, unless the anomaly forecast probability is very high. For a detailed description of how this works, see notes on the following page. Equal Chances (EC) indicates areas for which the models can- not predict the temperature with any confidence. EC is used as a "default option" representing equal chances or a 33.30/0 probability for each tercile, indicating areas where the reliability (i.e., 'skill') of the forecast is poor. Figure 10a. Long-lead national temperature forecast for January 2006. (released Dec. 30, 2005) A = Above 60.0-69.90/0 50.0-59.90/0 40.0-49.90/0 . 33.3-39.90/0 Figure 10b. Long-lead national temperature forecast for Jan. - Mar. 2006. (released Dec. 15, 2005) B = Below . 40.0-49.90/0 D 33.3-39.90/0 Figure 10c. Long-lead national temperature forecast for Feb. - Apr. 2006. (released Dec. 15, 2005) EC = Equal Chances Figure 10d. Long-lead national temperature forecast for Mar. - May 2006. (released Dec. 15, 2005) On the Web - For more information and the most recent forecast images, visit: http://WWw.cpc.ncep.noaa.gOv/products/predictions/multi- season/13_seasonal_outloOks/color/churChill.html. Please note that this website has many graphics and may load slowly on your computer. - The CPC "discussion for non-technical users" is at: http://www.cpc.noaa.gov/products/predictions/90day/fxus05.html - For I RI forecasts, visit: http://iri.columbia.edu/climate/forecast/net_asmt/. More information about temperature distributions at specific stations in Colorado, Utah, Wyoming, and across the West can be found at the Western Regional Climate Center, httQ://www.wrcc.dri.edu/CLIMATEDATA.html. FORECASTS 11 3