Winter Weather Forecast 2011

WINTER WEATHER FORECAST
LOCAL FORECAST INFORMATION- NWS
LOCAL FORECAST INFORMATION- WX CHANNEL
LOCAL FORECAST INFORMATION- ACCU WX
LOCAL FORECAST INFORMATION- RAYS WX
LONG RANGE FORECASTS- RAYS WX
LA NINA/ EL NINO
EL NINO- GENERAL EFFECTS
LA NINA- GENERAL RELATIONSHIPS
La Nino Winter
2007
La Nina Winter
2011
Fly Gap RanchCentral Texas
LONG RANGE FORECASTS- ACCU WEATHER
LONG RANGE FORECAST- NOAA
WOOLY WORMS
Mike Peters, an entomologist at the
University of Massachusetts,
doesn't disagree, but he says there
could, in fact, be a link between
winter severity and the brown band
of a woolly bear caterpillar.
"There's evidence," he says, "that
the number of brown hairs has to
do with the age of the caterpillar—
in other words, how late it got
going in the spring. The [band]
does say something about a heavy
winter or an early spring. The only
thing is . . . it's telling you about
the previous year."
NORTH AMERICAN OSCILLATION +
NORTH AMERICAN OSCILLATION -
HISTORIC INDEX
COLD AIR DAMMING
Phenomenon that occurs all over the world – but in
U.S. occurs on the east side of the Rockies and on
the east side of the Appalachians
Can occur any time of the year – most prevalent in
the winter months
WINTER CLIMATE AT ASHEVILLE, NC
WNC AVERAGE ANNUAL PRECIPITATION
Topography drives our rain and snow
PATTERNS TO WATCH FOR
Cold Air Damming
Northwest flow snow events
Gulf Lows in the cold months
Cold Air Damming
Low-level cold air mass is trapped topographically
Freezing Rain Events in the United States 1982-1990
(after Robbins and Cortinas, 1996)
NORTHWEST FLOW SNOW EVENTS
Snowfall in the southern Appalachians produced - or augmented - by upslope flow caused by
low-level northwest winds - Very localized snow typically not associated with synoptic
scale precipitation
Knoxville
NC Mountains
Greenville
NORTHWEST FLOW SNOW EVENTS
EXAMPLE OF SNOW DISTRIBUTION
Typical distribution of snow flurries and snow showers during NW flow
event in which moisture (windward cloud field) extends along entire range
of Appalachians. Note the proximity of the snow to the TN/NC border.
CHRISTMAS 2010 SNOW EVENT- GULF LOW
JANUARY 10-11, 2011 EVENT
ASHEVILLE WINTER DATA- WARMEST JAN 1950
ASHEVILLE WINTER DATA-COLDEST JAN 1977
INTERESTING WINTER FACTS
Coldest Jan Day Jan 21st 1985
below normal
8 / -16
41 degrees
Warmest Jan Day Jan 22nd, 1969 65/ 57
above normal
26 degrees
Snowiest Month Feb 1969 25.5 inches
64% of the time our seasonal snowfall is 15 inches of
less
CHRISTMAS TIME SNOWFALL- DOWNTOWN
2009 Trace
2010 8.1 inches
Christmas Eve 26 events 24%
Christmas Day 34 events 31%
1890
1895
1900
1905
1910
1915
1920
1925
1930
1935
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
Asheville Seasonal Snowfall by Year- Avg ~12.5 in
60.0
50.0
40.0
30.0
20.0
10.0
0.0
Series1
SNOWFALL AND SNOW DAYS –BUNCOMBE COUNTY
40.0
35.0
30.0
25.0
Seasonal Snowfall
20.0
Snow days
15.0
10.0
5.0
0.0
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
SNOWFALL DISTRIBUTION SINCE 1890-122 YEARS
35
30
25
20
Seasons
15
Percent
10
5
0
0-5
Inches
5-10
Inches
10-15
Inches
15-20
Inches
20-25
Inches
25-30
Inches
30-35
Inches
35-40
Inches
40-45
Inches
45-50
Inches
BOONE SNOWFALL
SOME WEATHER AND CLIMATE WEB RESOURCES
http://www.hikewnc.info/areainfo/wxclimate.html
http://www.raysweather.com
http://www.erh.noaa.gov/er/gsp/
http://www.ghcc.msfc.nasa.gov/GOES
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fcst/home.rxml
http://ggweather.com/loops/ncep_loops.htm
http://www.meteo.psu.edu/~gadomski/ewall.html
http://cirrus.sprl.umich.edu/wxnet/
http://www.weathercore.com/dir/index.php?topic=Main_We
http://weather.unisys.com/
ather_Sites/
http://modis.gsfc.nasa.gov/data/
http://weathercore.com
http://www.cpc.ncep.noaa.gov/
http://www.ncdc.noaa.gov/climate-monitoring/index.php
http://www.weather.gov/
http://www.nhc.noaa.gov/
http://www.intellicast.com/
http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller
WINTER FORECAST 2011-2012 (DEC-MAR)

How many, how strong, how deep and the exact track of these systems determine
our overall winter precipitation (rain, snow and ice amounts.)

December 2011 looks quite mild with generally a westerly flow and normal
precipitation. (After Wednesday’s event - If we get any major snow- don’t think it
will occur until after Christmas)

Remainder of the winter will play a tug of war between warm and normal to wet
alternating with dry and cold .

Think we will have a snowstorm or two, several NW flow events and the return of
the possibility of several significant ice storms in east Buncombe and Henderson
counties. (very little to no ice last year)

Snowfall above average 15 inches. +