A Busy Severe Weather Season in Eastern New York and Western New Englan

by Kenneth LaPenta

The 1998 severe weather season was an active one in eastern New York and western New England. Based on preliminary data through October 1, there were 156 severe weather events (damaging winds, large hail and tornadoes) in 1998. That total could still rise as the season is not over yet. A few years (most notably 1989) produce significant severe weather outbreaks in October and November. The record for severe weather events in one year in the Albany County warning area is 207 in 1994. In New York State this past year there were at least 23 tornadoes (the record is 25 in 1992), with one tornado in southern Vermont and one in Litchfield County, Connecticut. The most damaging tornado was the F3 (winds 158 to 206 mph) that struck Mechanicville in Saratoga County and adjacent portions of northwest Rensselaer County on May 31. This supercell produced tornadoes all the way east into Vermont.

In many ways it was an unusual severe weather season. The first severe weather (nickel size hail in Herkimer County, New York) occurred early, on January 9^th.. This was part of the Great January Ice Storm and Flood. There were long stretches of rather quiet weather, but when severe storms did strike, they were often big events. After a quiet start, a strong squall line produced 24 events on Friday, May 29^th.. The weather briefly settled down on Saturday, but Sunday, May 31 brought major tornadoes to the region. On that day, the National Weather Service Office in Albany issued 48 severe thunderstorm and tornado warnings, a record for one day. More tornadoes struck central and western New York on June 2, but fortunately these storms weakened as they reached eastern New York. June, July and August were rather quiet with only 49 severe weather events during the entire three months. September brought overnight severe storms caused by large, well-organized bow echoes on Labor Day morning and on the 26^th. - 27^th. The Labor Day storm certainly qualifies as a derecho.

Storm spotters played an integral role in the National Weather Service's ability to provide accurate warnings to the public. Quick receipt of severe weather reports helped National Weather Service meteorologists manning our Doppler radar to issue warnings with greater confidence. In addition, these reports provide useful information to ongoing research studies that are designed to help make our warning system even better.

La Niña - Do You Need to Hibernate?

by Carl Cerniglia

Every Fall, people across the Northeast begin to wonder, what will winter be like this year?' This is partially due to the wide range of possibilities that can be expected in this part of the country. Some winters are rather mild with plenty of rain and little snow, while others make you think about buying a home in Florida!

There are many variables that may influence the weather each winter season. Most of these variables are not yet fully understood. However, we have begun to accurately forecast one phenomenon that affects climate on a global scale. This phenomenon is called the ENSO cycle, short for El Niño/Southern Oscillation.

ENSO is born in the tropical waters of the Pacific ocean and impacts the weather worldwide. The

ENSO cycle is made up of two parts, El Niño and La Niña. The El Niño portion of the cycle, also known as the warm phase due to warmer than normal water temperatures in the eastern Pacific, has a detectable effect on winter in the Northeast. The stronger the El Niño, the warmer our winter is likely to be. The record strong El Niño of last year resulted in our winter months being as much as eight degrees above normal. That is a significant impact and definitely shows up in the heating bills!

This winter, the Northeast will be under the influence of El Niño's twin sister, La Niña, who just happens to have an opposite personality. La Niña is the result of colder than normal waters in the eastern Pacific and also has an impact on Northeast winters. The influence is not as dramatic as El Niño's, but winter temperatures average out cooler than normal for most of the season.

The forecast this winter is for a La Niña of moderate strength. Looking back at 29 La Niñas that

>have occurred since 1874, a pattern begins to emerge in upstate New York and adjacent western New England. The early and middle parts of winter are a bit colder than normal. November, December and January have monthly average temperatures 1 to 1.5 degrees below normal with February averaging near normal. The largest impact of La Niña occurs in the spring. March and April average 2.5 to 3.5 degrees colder than normal which will in effect drag out winter early next

year. The temperature data also implies that La Niña may enhance cloud cover over the area into early summer.

The data also indicates a bit of a pattern in the snowfall that can be expected across the region. The amount of snowfall from one La Niña to another varies quite a bit. However, in the long-term average, November and January receive near normal amounts of snow. February averages about 15% less snow than normal while December gets around 25% less. Again, the most significant impact occurs in the spring. March averages 35% more snow than normal and April nearly 50% more than normal. Better wait until May to put the snow shovels away!

High Winds: a Real but Sometimes Unperceived Threat to New York and New England

by John Quinlan

High Wind events (excluding those directly associated with severe local storms) are relatively common across New York and New England. They tend to occur during the Fall, Winter and Spring seasons when storm systems are the strongest and only rarely occur during the Summer season when storm systems tend to be weak.

The National Weather Service defines a High Wind event as sustained wind speeds of 40 mph or greater lasting for an hour or longer, or wind speeds of 58 mph or greater for any duration. The National Weather Services issues High Wind Warnings, High Wind Watches, High Wind Outlooks, and Wind Advisories which are issued for lesser events. High Wind Warnings are usually issued for the first forecast period with activation of the tone alert on NOAA Weather Radio for short fuse, especially dangerous situations. High Wind Watches are issued when a High Wind condition is expected in the second forecast period while High Wind Outlooks are issued similar to other long range outlooks using a Special Weather Statement. Wind advisories are usually issued for the first forecast period for sustained winds of 31 to 39 mph lasting for an hour or longer, or wind gusts 46 to 57 mph for any duration.

There are four basic types of High Wind events: Gradient High Winds, Mesoscale High Winds, Channeled High Winds and Tropical Cyclone Associated High Winds. Gradient High Winds are the most common and occur over a large area due to synoptic scale, extra tropical low pressure systems (such as Nor'easters). Mesoscale High Winds usually occur in the wake of convection. These high winds are separated from the main area of convection so they are not covered by convective warnings. Channeled High Winds are the most common over localized areas as air is channeled through constricted passages such as deep, narrow mountain valleys (such as Pleasant Valley in Lamoille County in Vermont and Platte Clove in Greene County in New York) or tall buildings in cities. Tropical Cyclone Associated High Winds can occur several hundred miles inland from the coast of a tropical cyclone which makes landfall. Since Hurricane and Tropical Storm Warnings are not appropriate for inland areas, the National Weather Service has two products to cover such events: Inland High Wind Warning For Hurricane Force Winds and Inland High Wind Watch For Hurricane Force Winds.

Numerous High Wind events have occurred across New York and New England resulting in deaths and injuries as well as significant property damage. Two of the most devastating High Wind events on record occurred across New York and New England on November 24, 1950 which was called the "Great Appalachian Storm" (peak wind gust at Albany 83 mph and New York City 94 mph) and November 12-13, 1992 (several million dollars in damage and 5 injuries). Other memorable High Wind events in recent years occurred on December 25, 1992: November 28, 1993: February 24-25, 1996: and November 8, 1996.

Review of the Summer of 98

by Hugh Johnson

After the severe outbreak of May 31^st, June roared in more like March than the beginning of summer. Temperatures only reached the 60s for 7 of the first 8 days of the month, along with strong gusty breezes. Then the rains came back. Rain fell on 9 straight days, which in turn triggered some flooding of small streams and even large rivers. It took until June 19^th to see the first 80 degree reading of the month. Two days later we reached our highest temperature of the month with 88 degrees. Despite the very cool start, June's average temperature of 66.3 was just 0.7 of a degree below normal. This was due to muggy nights the second half of the month, since humidity values remained very high from all the rain. The rainfall total of 6.59 inches was nearly twice the thirty year normal. July was a much quieter month weatherwise. For only the second time this year, rainfall was less than normal - 2.74 inches versus the thirty year normal of 3.18. Most of the rain fell on July 8^th with the rest from scattered thunderstorm activity. The CESTM building took a direct hit from lightning on the 20^th. A persistent northwesterly jetstream aloft prevented any heat waves from locking in. Temperatures fell short of normal, 70.9 versus 71.8 with the high again just 88 degrees on the 16^th.

August was a quiet weather month. Rainfall was once again on the low side, with the total 2.21 accumulation more than an inch below normal. There was a significant disparity of rain from north to south. A persistent storm track kept folks wetter than normal north of the Mohawk Valley, while the Bermuda High finally established a beachhead to the south, keeping that area parched and quite warm. At the Albany International Airport, the monthly average of 71.0 was more than 1.4 degrees above normal. However there were still no days reaching 90. Eighty nine degrees on the 24^th tied March 31^st for the warmest day, not only of this month, but for the year as well.

Temperatures in September ran 2.4 degrees above normal. The highest reading was 89 on the 6^th, making this the first year since 1874 that no 90 degree days were officially recorded in Albany. The monthly rainfall, despite two severe weather outbreaks, was only 2.21, nearly an inch below normal.

WCM Words

by Dick Westergard

Once again, check the mailing label on this issue of StormBuster. It contains the date of your last training. If that date is more than 2 years ago, you should plan to attend another training session soon. Once that date is more than 5 years in the past, your name will be purged from our database.

At this writing, plans are being finalized for the Fall advanced Spotter Training sessions. There will be eight of them this year. I hope you can make it to one.

Winter Weather Awareness Week in New York and Vermont is November 15 through 21. As we prepare for winter, it seems appropriate to remind everyone of what we'd like you to call us about during the winter season (November through April). 1)Snowfall of 4 inches or more in 24 hours. 2) Any Freezing rain or drizzle. 3)One inch or more of rain in 4 hours or less. 4) Ice jams or Flooding, including bankfull or near bankfull streams. 5) Damaging winds causing downed trees or power lines, and any structural wind damage.>