Regardless of how accurate they turn out, I enjoy reading these.<br><br>First there's George "the dude whose forecast broke my heart last year" Taylor. He is predicting above normal temperatures, and above normal precipitation. <br><br>Pasted from
OCS
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Fall & Winter Forecast 2005-2006<br>
<br>Overview of the Upcoming Season<br>George H. Taylor, State Climatologist<br>Cadee Hale, Publication Manager<br>Oregon Climate Service, Oregon State University <br>August 31, 2005<br><br>
Last Year's Forecast<br>Last year we said, "We expect generally below-average temperatures during the first half of the season (Oct-Dec), with normal or somewhat above-average precipitation statewide. The second half of the year (Jan-Mar) should see above-average temperatures statewide and average or above-average precipitation (with western Oregon more likely to be above average).<br><br>"There appears to be a good chance of one or more extreme events this winter, particularly wind storms and rain storms."<br><br>We didn't anticipate the very dry mid-winter (Nov-Feb). Fall was quite wet, however, and spring was even wetter. But we sure didn't expect the dry winter.<br><br>On the other hand, in February we predicted a wet spring, at the same time NOAA was predicting a dry one, so we count that a success.<br> <br>
This Year's Forecast<br>Below are the factors we used to generate this year's forecast, along with the bottom line for this fall and winter: mild and wet.<br><br>We have also included forecasts from two government agencies, three Farmer's Almanacs, and two friends, Steve and Grant.<br> <br>
Sea Surface Temperatures<br>Sea surface temperature (SST) anomalies reported by FNMOC on August 29, 2005 show slightly negative values in most of the eastern Tropical Pacific. There has been a steady decline in SST anomalies since spring, 2005.<br><br>
Analog Years<br>In addition to analyzing El Niño and La Niña conditions from past years, we looked for ways in which years in the past resembled this year. Using the months January - July, we compared past years with 2005 and identified the closest matches. These are listed below by year. Some of the criteria we used are: <br><br>1. Multi-decadal phase. OCS has identified periods of 20-25 years with generally warm-dry or cool-wet conditions. In each phase, about 75% of all years have been above (wet phase) or below (dry phase) average. The last wet phase was from the late 1940's until the mid-1970's. We believe that we reentered a wet phase in the mid-1990's, making a wetter than average year much more likely than a dry one. Probably the best indicator of these cycles is the Pacific Decadal Oscillation (PDO) parameter. <br>2. The Multivariate ENSO Index (MEI) is based on six main observed variables over the tropical Pacific. These six variables are: sea-level pressure (P), zonal (U) and meridional (V) components of the surface wind, sea surface temperature (S), surface air temperature (A), and total cloudiness fraction of the sky (C). The MEI is computed separately for each of twelve sliding bi-monthly seasons (Dec/Jan, Jan/Feb,...,Nov/Dec). The closest analog years to 2005 are 1953, 1959, 1978 and 1990. <br>3. Other indices. In addition to MEI, OCS examined sea surface temperatures, and the Eastern Pacific (EP), and Pacific-North America (PNA) indices and compared this year's observations with those of previous years. The closest analog years using these indices are 1952, 1957, 1969, 1973 and 1993. <br>4. Solar cycle. Solar radiation changes are known to have effects on climate, although there is still debate within the climate community regarding the degree and character of those effects. Currently we are approaching a solar minimum period. The closest analog years are 1952, 1974, 1987, and 1994. <br>5. Hurricanes. Years ago we noticed a strong correlation between the number of Atlantic hurricanes and Pacific Northwest climate the following winter. A graph of hurricane days vs.Portland winter precipitation appears here. The best match for this year's very busy hurricane season is 1995. <br>6. Regional climate patterns. Past climate trends (for the calendar year so far) were studied to try to find analogs. The best matches were 1957, 1962, 1988 and 1995. <br><br>Based on a composite of those analyses, the analog years which most closely resemble 2005 (considering the months Jan - Aug) are (in descending order of similarity, beginning with the most similar):
1995, 1969, 1952, 1954, 1957 and 1973. Using a map composite tool provided by the NOAA-CIRES Climate Diagnostics Center, Boulder Colorado from their Web site at
www.cdc.noaa.gov
, we created the following temperature and precipitation anomaly maps:
element period discussion
temperature Oct-Dec above normal west of the Rockies, below normal in the east.
precipitation Oct-Dec near to slightly above normal in the Northwest, below normal in the southwestern U.S.
temperature Jan-Mar mostly above normal in the western U.S. except for extreme northern states
precipitation Jan-Mar above normal along the west coast and the northern intermountain states; dry in the center of the country
Note that 1995, the best overall fit (the year that most closely resembled 2005), was weighted twice as heavily as the other years.
A breakdown by climate division is as follows:
temperatures: <br>climate division october-december january-march <br>1 - Oregon Coast Above normal Above normal <br>2 - Willamette Valley Above normal Above normal <br>3 - Southwest Interior Above normal Above normal <br>6 - Northeast Oregon Above normal Above normal <br>7 - Southeast Oregon Above normal Above normal <br> <br>
precipitation:<br>climate division october-december january-march <br>1 - Oregon Coast Near normal Above normal <br>2 - Willamette Valley Slightly above normal Above normal <br>3 - Southwest Interior Slightly above normal Above normal <br>6 - Northeast Oregon Slightly above normal Above normal <br>7 - Southeast Oregon Slightly above normal Above normal <br><br>
Extreme Weather Events in Analog Years<br>Extreme events were fairly common during the analog years identified above (1995, 1969, 1954, 1957, 1973); these included wind storms, floods, and ice storms. For example, major events included:<br><br>Wind storms: 1952-53, 1995-96<br>Floods: 1952-53, 1973-74, 1995-96<br>Ice storms: 1969-70, 1995-96<br>1995, the best overall match with this year (2005), had an abundance of extreme events:<br><br>- Floods in November and February<br>- Ice storms in December and February<br>- Extreme wind storm (biggest in at least 15 years) in December<br><br>With that in mind, it would appear that the chaces for an extreme event are
quite high this year compared with an average year. An active year seems likely!<br> <br> <br>
Forecast Discussion<br>It is likely that this year will see relatively mild temperatures, and above-average precipitation, especially in the second half of the year. We expect early fall conditions to remain mild and dry well into October before winter storms begin, probably some time in November.<br><br>Every year, the most common question we hear is, "will we see low elevation snow?" we guess (which is all we can do in good faith -- predicting snow is really tough!) is that low elevation snow will not occur. If snow DOES occur, it is more likely after January 1. Sorry, that's as exact as we can be!<br><br>Watch for extreme events. The Oregon coast will be especially susceptible to wind storms and flooding.<br><br> <br><br>
Topic Author
<br><br>Positive vibes only from now on!!!!!!!!!!!!!!!! 