200809 winter outlook - northwest river forecast … · winter outlook 200809. 22 2008/2009 water...
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200809 200809 Winter Winter OutlookOutlook
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El NiñoEl Niño
La NiñaLa Niña
Winter Outlook 200809Winter Outlook 200809
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El Niño ImpactsEl Niño Impacts
TemperatureTemperature PrecipitationPrecipitation
Winter Outlook 200809Winter Outlook 200809
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La Niña ImpactsLa Niña Impacts
Winter Outlook 200809Winter Outlook 200809
TemperatureTemperature PrecipitationPrecipitation
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NOAA monitors the Oceanic Niño Index (ONI), a NOAA monitors the Oceanic Niño Index (ONI), a 3month running average of Sea Surface 3month running average of Sea Surface Temperature departures along the central Temperature departures along the central tropical Pacific. tropical Pacific.
¤ El Ni¤ El Niñño = Positive ONI ≥ +0.5°Co = Positive ONI ≥ +0.5°C
¤ La Niño = Negative ONI ≤ 0.5°C¤ La Niño = Negative ONI ≤ 0.5°C
NOAA’s Definitions of NOAA’s Definitions of El Niño and La Niña EventsEl Niño and La Niña Events
Winter Outlook 200809Winter Outlook 200809
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What’s Happening in Pacific?What’s Happening in Pacific?
Below averageBelow average
Winter Outlook 200809Winter Outlook 200809
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ONI Trend 19502008ONI Trend 19502008
199798199798198283198283
199900199900200708200708La NiñaLa Niña
El NiñoEl Niño
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Since Fall of 2006…Since Fall of 2006…
WeakWeak0.50.9°C0.50.9°C
ModerateModerate1.01.4°C1.01.4°C
StrongStrong≥≥1.5°C1.5°C
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Southern Oscillation Southern Oscillation Index (SOI)Index (SOI)
Pressure correlations between Indian Ocean Pressure correlations between Indian Ocean and the eastern tropical Pacific Ocean.and the eastern tropical Pacific Ocean.La Niña La Niña effectseffects
El Niño effectsEl Niño effects
200708200708
200607200607
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Southern Oscillation Southern Oscillation Index (SOI)Index (SOI)
Strong Correlations with summer SOI and Strong Correlations with summer SOI and winter rainfall, snowfall, and temperatureswinter rainfall, snowfall, and temperatures
In general…In general…La Niña summers (positive SOI)…La Niña summers (positive SOI)…
= above average winter precipitation= above average winter precipitation = below average winter temperatures.= below average winter temperatures.
El Niño summers (negative SOI)…El Niño summers (negative SOI)…= below average winter precipitation= below average winter precipitation
= above average winter temperatures.= above average winter temperatures.
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Southern Oscillation Southern Oscillation Index (SOI)Index (SOI)
Summer 2008 SOISummer 2008 SOISlightly PositiveSlightly Positive
+ 2 to 3+ 2 to 3So, indicates weak So, indicates weak La Nina effects La Nina effects continue through continue through November.November.
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Forecast thru Apr 2009Forecast thru Apr 2009
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But, What Will But, What Will Winter Be Like?Winter Be Like?
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Temperature Probabilities
October DecemberOctober December January MarchJanuary March
Winter Outlook 200809Winter Outlook 200809
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So, will So, will there be there be a lot of a lot of
rain this rain this Winter?Winter?
Winter OutlookWinter Outlook200809200809
Cartoon used with Cartoon used with permissionpermission by T. McCracken by T. McCracken
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Precipitation Probabilities
October DecemberOctober December January MarchJanuary March
Winter Outlook 200809Winter Outlook 200809
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Oct - Oct - DecDec
Jan - Jan - MarMar
Winter Outlook 200809Winter Outlook 200809
Temperature OutlookTemperature Outlook
Slightly Slightly aboveabove
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Oct - Oct - DecDec
Jan - Jan - MarMar
Winter Outlook 200809Winter Outlook 200809
Rainfall OutlookRainfall Outlook
slightly slightly belowbelow
belowbelow
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Oct - Oct - DecDec
Jan - Jan - MarMar
Winter Outlook 200809Winter Outlook 200809
Snowfall OutlookSnowfall Outlook
slightly slightly belowbelow
Little if any snow potential interior west sideLittle if any snow potential interior west side
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CoastCoast West InlandWest Inland
Winter Outlook 200809Winter Outlook 200809
Windstorm OutlookWindstorm Outlook
Storms with Storms with winds at least:winds at least: 5570 mph: 585570 mph: 587085 mph: 37085 mph: 385+ mph: 185+ mph: 1
Storms with Storms with winds at least:winds at least:
4555 mph: 474555 mph: 476070 mph: 26070 mph: 270+ mph: 070+ mph: 0
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►►Neutral year, with minor La Niña effects.Neutral year, with minor La Niña effects.
► ► Near Normal Temperatures.Near Normal Temperatures.
► ► Normal Precipitation thru Dec, then Normal Precipitation thru Dec, then turning a bit drier than normal.turning a bit drier than normal.
►►68 low to moderate windstorms on Coast.68 low to moderate windstorms on Coast. 1 strong storm (1 strong storm (over 85 mph windsover 85 mph winds))
►►Little if any threat of low elev. inland snowfall.Little if any threat of low elev. inland snowfall.
Winter Outlook 200809Winter Outlook 200809
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2008/2009 Water Supply OutlookColumbia River at The Dalles
Jan-Jul 2009Seasonal Volume
108 Million Acre-Feet (Near Normal)