2010 Winter Outlook & 2010 Winter Outlook & ENSO updateENSO update
Keith StellmanKeith StellmanNational Weather Service Shreveport, LANational Weather Service Shreveport, LA
National Weather ServiceNational Weather Service
““Oscillations”Oscillations”
ENSO (El Nino Southern Oscillation)ENSO (El Nino Southern Oscillation) The one you’ve all heard aboutThe one you’ve all heard about El Nino, La Nina, and neither (Neutral)El Nino, La Nina, and neither (Neutral)
Normal Normal Pacific Pacific CirculationCirculation
El NinoEl NinoLa NinaLa Nina
Pacific SST Departures (Pacific SST Departures (ooC) C)
Large positive anomalies associated with El Niño decreased beginning in late February 2010, becoming negative in late April. The large negative anomalies since June 2010 are consistent with the development and continuation of La Niña.
La NiñaLa Niña
NOAA Operational Definitions for NOAA Operational Definitions for El Niño and La El Niño and La NiñaNiña
El Niño: characterized by a SST anomalies greater than or equal to +0.5°C.
La Niña: characterized by a SST anomalies less than or equal to -0.5°C.
By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be these thresholds must be exceeded for a period of at least 5 consecutive exceeded for a period of at least 5 consecutive overlapping 3-month seasons.overlapping 3-month seasons.
NiNiño Region SST Departures and Forecast (ño Region SST Departures and Forecast (ooC)C)
ForecastForecast
The latest weekly SST departures are:The latest weekly SST departures are:
Niño 4 Niño 4 -1.5ºC -1.5ºC
Niño 3.4 Niño 3.4 -1.5ºC-1.5ºC
Niño 3 Niño 3 -1.5ºC-1.5ºC
Niño 1+2 Niño 1+2 -0.6ºC-0.6ºC
La Nina ForecastLa Nina Forecast
Stg El Nino
Stg La Nina
Neutral
Hawaii
ENSO since 1950
El Niño
La Niña
neutral
The most The most recent ONI recent ONI value (August – value (August – October 2010) October 2010) is -1.3is -1.3ooC.C.
ONI = Oceanic Nino ONI = Oceanic Nino IndexIndex
Historical El Niño and La Niña EpisodesHistorical El Niño and La Niña Episodes
Strongest El NinoStrongest El Nino
1957, 1966, 1972, 1983, 1987, 1991, 1998
Highest
El Niño ONI Value
Lowest
La Nina ONI ValueJAS 1951 - NDJ 1951/52 0.8 ASO 1949 – FMA 1951 -1.7
MAM 1957 – MJJ 1958 1.7 MAM 1954 – DJF 1956/57 -2.1
JJA 1963 – DJF 1963/64 1.0 ASO 1962 − DJF 1962/63 -0.8
MJJ 1965 – MAM 1966 1.6 MAM 1964 – DJF 1964/65 -1.1
OND 1968 – MJJ 1969 1.0 NDJ 1967/68 – MAM 1968 -0.9
ASO 1969 – DJF 1969/70 0.8 JJA 1970 – DJF 1971/72 -1.3
AMJ 1972 – FMA 1973 2.1 AMJ 1973 – MAM 1976 -2.0
ASO 1976 – JFM 1977 0.8 SON 1984 – ASO 1985 -1.0
ASO 1977 - DJF 1977/78 0.8 AMJ 1988 – AMJ 1989 -1.9
AMJ 1982 – MJJ 1983 2.3 ASO 1995 – FMA 1996 -0.7
JAS 1986 – JFM 1988 1.6 JJA 1998 – MJJ 2000 -1.6
AMJ 1991 – JJA 1992 1.8 SON 2000 – JFM 2001 -0.7
AMJ 1994 – FMA 1995 1.3 ASO 2007 – AMJ 2008 -1.4
AMJ 1997 – AMJ 1998 2.5
AMJ 2002 – FMA 2003 1.5
MJJ 2004 – JFM 2005 0.9
JAS 2006 - DJF 2006/07 1.1
Strongest La NinaStrongest La Nina
1951, 1955, 1973, 1989, 1999, 2007
ENSO (El Nino Southern Oscillation)ENSO (El Nino Southern Oscillation)
El Nino global effectsEl Nino global effects
La Nina global effectsLa Nina global effects
During La Niña (cool phase of ENSO), the jet During La Niña (cool phase of ENSO), the jet stream's position shows a large dip in the central stream's position shows a large dip in the central and Eastern US. and Eastern US.
Typical Patterns during La NiTypical Patterns during La Niña Wintersña Winters
• TemperatureTemperature
• PrecipitationPrecipitation
• Jet StreamJet Stream
Winter Outlook - TemperatureWinter Outlook - Temperature
Winter Outlook - PrecipWinter Outlook - Precip
La Nina years impactsLa Nina years impacts
La Nina years to compareLa Nina years to compare
1.73-74
2.83-85
3.87-89
4. 95-96
5. 1998-2000
6. 2007-2008
Local Winter WeatherLocal Winter Weather
• Major ice eventsMajor ice events during La Nina years include – February 1996 (moderate La Nina) – NE LA
• 2 inches of Ice in NE LA
– December 1999 (Moderate La Nina) NW LA/NE TX– December 2000 (moderate La Nina) – East TX/SW AR.
Texarkana, TX Dec 2000
Hope, AR Dec 2000
1984-85 Summary1984-85 Summary• November 24,1973November 24,1973
– East TX Tornado outbreak (F1-F2)East TX Tornado outbreak (F1-F2)
• December 3, 1973December 3, 1973– Eastern LA Tornados (F2)Eastern LA Tornados (F2)
• January 1-3,1974January 1-3,1974– Temps < 32F with 1” of precip Temps < 32F with 1” of precip
RecordedRecorded
• January 19, 1974January 19, 1974– F3 tornado (deep E TX)F3 tornado (deep E TX)– Tornadoes across east TXTornadoes across east TX
• March 20, 1974March 20, 1974– Several F3 Tornados (Lufkin->San Several F3 Tornados (Lufkin->San
Augustine-> Natchitoches LA)Augustine-> Natchitoches LA)– Numerous injuriesNumerous injuries
• March 28, 1974 March 28, 1974 – NE LA tornadosNE LA tornados
• Numerous Hail/Wind reports through Numerous Hail/Wind reports through AprilApril
• Snowstorm occurred in January 1975Snowstorm occurred in January 1975
1973-74-75 Summary1973-74-75 Summary
• Feb 1-2,1985Feb 1-2,1985– 4-6 inches of snow 4-6 inches of snow
• April 5,1985April 5,1985– NE LA TornadoesNE LA Tornadoes
• April 23,1985April 23,1985– F3 tornadoes (NW LA)F3 tornadoes (NW LA)– Tornadoes across east TXTornadoes across east TX
1988-1989 Weather Summary1988-1989 Weather Summary
• Nov 19 and 25, 1988 – Severe Weather Nov 19 and 25, 1988 – Severe Weather – Numerous Hail/Wind Reports– Several Tornadoes (Cass, Marion, Upshur, Angelina, Panola)
• Feb 4-7,1989Feb 4-7,1989– Temperatures < 30F with 0.20 inches of precipitation (not snow)Temperatures < 30F with 0.20 inches of precipitation (not snow)– MLU reported ~0.5 inches of iceMLU reported ~0.5 inches of ice
• April 3, 29 and May 5, 1989April 3, 29 and May 5, 1989– Severe Weather Days
– Large Hail, Wind Damage
– Tornadoes across NW LA (Caddo/Bossier)
1995-1996 Weather Summary1995-1996 Weather Summary• Feb 3, 1996Feb 3, 1996
– 2 inches of Ice in NE LA2 inches of Ice in NE LA
• Jan 31-Feb 4, 1996Jan 31-Feb 4, 1996– Temperatures range from 14F-33F in SHVTemperatures range from 14F-33F in SHV– 0.5 inches0.5 inches
• Several Hail/Wind Events– April 20,22 (Baseball Hail)
• East Texas -> NW LA -> NE LA• 80 mph wind in Monroe• Tornados in Madison Parish/Tyler area
• No major tornado outbreaksNo major tornado outbreaks
1998-1999 Weather Summary1998-1999 Weather Summary• December 22,1998December 22,1998
– Ice Storm across the ArklatexIce Storm across the Arklatex– Estimated $5-$6 Million in damagesEstimated $5-$6 Million in damages
• January 1, 1999January 1, 1999– Tornado outbreakTornado outbreak
• F2 in Shreveport (10:26 PM), DoylineF2 in Shreveport (10:26 PM), Doyline• F1 in SligoF1 in Sligo
• January 22, 1999January 22, 1999– Larger Severe Weather episodeLarger Severe Weather episode
• Tornados and Hail along and south of I-20Tornados and Hail along and south of I-20
• Feb 27, Mar 2, Mar 12Feb 27, Mar 2, Mar 12
April – May 1999April – May 1999• April 3, 1999April 3, 1999
– Bossier City F4 TornadoBossier City F4 Tornado• BentonBenton• 7 Killed7 Killed
– Summerfield F3 TornadoSummerfield F3 Tornado
• April 26, 1999April 26, 1999– 100 MPH wind at Shreveport
• Numerous high wind reports across the area
• May 4, 1999May 4, 1999– F2 in Plain Dealing (LA), Kilgore F2 in Plain Dealing (LA), Kilgore
TXTX– F3 in Mt Vernon, Avery, DekalbF3 in Mt Vernon, Avery, Dekalb
• Dekalb Elementary and High School Dekalb Elementary and High School hithit
Dekalb, TX Dekalb, TX TornadoTornado
The 2000 Bug!!The 2000 Bug!!• April 23, 2000April 23, 2000
– Largest tornado outbreak in Largest tornado outbreak in the Arklatex Historythe Arklatex History
• 28 tornadoes ranging from F1-F328 tornadoes ranging from F1-F3
• December 2000December 2000– 2 major Ice Storms2 major Ice Storms
• Dec 12 and 23Dec 12 and 23• Estimated $500-$700 million in Estimated $500-$700 million in
damagesdamages
– 1 major snowfall1 major snowfall• New Years EveNew Years Eve• 4-6 inches of snow fell4-6 inches of snow fell
Independence Bowl - 2000
Tornado Tracks, Easter 2000
20082008• Feb-MarchFeb-March
– Arp, Hooks, Longview Arp, Hooks, Longview TornadoesTornadoes
– Lindale/Bullard HailstormsLindale/Bullard Hailstorms– Texarkana HailstormTexarkana Hailstorm
• April-MayApril-May– Shreveport FloodsShreveport Floods
• New rainfall records (14 inches)New rainfall records (14 inches)
– San Augustine FloodSan Augustine Flood• 20 inches in 24 hours20 inches in 24 hours
– Leary, Henderson TornadosLeary, Henderson Tornados– Texarkana and Winnsboro Texarkana and Winnsboro
downburstsdownbursts
Leary
Texarkana
San Augustine
El Nino vs La NinaEl Nino vs La NinaEl Nino Tornado tracks
La NinaTornado tracks
• Winter/Spring Winter/Spring TornadoesTornadoes– Increased number during Increased number during
La Nina (right) when La Nina (right) when compared to El Ninocompared to El Nino
– http://www.coaps.fsu.edu/papers/impacts_enso_tornadic_activity/
– http://www.spc.noaa.gov/publications/cook/ensowntr.pdf
“…The Ohio River Valley and Deep South see a region of statistically significant increased tornadic activity during La Niña.”
Cool Season Outlook - Summary• Fall Severe Weather Season – Below Normal season most likely
outcome
• Winter Season Precip - more likely to see near to below normal precipitation
• Winter Season Temperatures – Above normal temperatures most likely outcome
• Winter Severe Weather – Near to Above normal season most likely outcome with at least 1 large event
• Winter Weather – Snowfall at a near normal risk – Ice events - above normal risk
• Spring Severe Weather – Above Normal Season
Consecutive Days TConsecutive Days Tmaxmax < 35F - SHV < 35F - SHV# Days End Date •7 12/26/1983 •5 1/22/1978 •4 2/ 4/1996 •4 12/19/1989 •4 1/14/1982 •4 1/14/1978 •4 1/11/1973 •4 1/28/1961 •4 2/ 2/1951 •3 1/ 2/2001 •3 1/29/2000 •3 1/13/1997 •3 2/ 6/1989 •3 1/ 8/1988 •3 2/ 3/1985 •3 1/ 4/1974 •3 1/ 9/1968 •3 12/23/1963
La NinaNeutralEl Nino
Heating Degree Days – (Nov-Mar)Heating Degree Days – (Nov-Mar)• Marshall, TXMarshall, TX
– Average is Average is 447447 from from 1972-20101972-2010• 1973-74: 1973-74: 395395• 1984-85: 1984-85: 490490• 1988-89:1988-89: 381381• 1995-96:1995-96: 474474• 1998-99:1998-99: 368368• 1999-2000:1999-2000: 338338• 2007-08:2007-08: 348348
• Shreveport, LAShreveport, LA– Average is Average is 406406 from from
1972-20101972-2010• 1973-74: 1973-74: 358358• 1984-85: 1984-85: 389389• 1988-89:1988-89: 390390• 1995-96:1995-96: 431431• 1998-99:1998-99: 330330• 1999-2000:1999-2000: 305305• 2007-08:2007-08: 365365
*Red indicates fewer heating degrees were needed which means warmer than normal
THANK YOU!!!
Keith StellmanKeith Stellman
NWS ShreveportNWS Shreveport
5655 Hollywood Ave.5655 Hollywood Ave.
Shreveport, LA 71109Shreveport, LA 71109
www.srh.noaa.gov/shv/briefingwww.srh.noaa.gov/shv/briefing
[email protected]@noaa.gov
Paducah, KY Ice storm – January 2009 Paducah, KY Ice storm – January 2009
Radar image on April 23, 2000 – Centered on ShreveportRadar image on April 23, 2000 – Centered on Shreveport
