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North Texas Winters During ENSO Neutral
Conditions
Daniel HuckabyJason Dunn
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Topics
El Niño/Southern Oscillation (ENSO) – current and future state
ENSO phase composites for upcoming winter• temperature• precipitation
Climate Prediction Center (CPC) outlooks ENSO phase vs. trends and other inputs
Drought re-emerging?
El Niño/Southern Oscillation (ENSO) – current and future state
ENSO phase composites for upcoming winter• temperature• precipitation
Climate Prediction Center (CPC) outlooks ENSO phase vs. trends and other inputs
Drought re-emerging?
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ENSO CategoriesNeutralNeutral
El NiñoEl Niño La NiñaLa Niña
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ENSO Neutral
Walker Circulation – low surface pressure in western equatorial Pacific; high surface pressure in eastern equatorial Pacific
Tropical convection is usually confined to the western equatorial Pacific. Stable, rain-free weather is typical near South America.
Walker Circulation – low surface pressure in western equatorial Pacific; high surface pressure in eastern equatorial Pacific
Tropical convection is usually confined to the western equatorial Pacific. Stable, rain-free weather is typical near South America.
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Model Projections
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ENSO Neutral to Prevail
Model consensus is for ONI to remain between -0.5 and 0.5 throughout the upcoming winter
Sea surface temperatures (SST) in equatorial Pacific continue to “reflect lingering aspects of La Niña”• recent decrease in SST• some cool anomalies
Pacific/North American teleconnection pattern (PNA)• currently neutral and likely remain so• positive correlation with ENSO phase
Model consensus is for ONI to remain between -0.5 and 0.5 throughout the upcoming winter
Sea surface temperatures (SST) in equatorial Pacific continue to “reflect lingering aspects of La Niña”• recent decrease in SST• some cool anomalies
Pacific/North American teleconnection pattern (PNA)• currently neutral and likely remain so• positive correlation with ENSO phase
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Oceanic Niño Index
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Winter Temperatures(1950-present)
Waco Max T Max T Min T
Neutral 48.3 59.4 37.2
El Niño 48.4 58.7 38.0
La Niña 50.2 61.3 39.1
1971-2000 48.4 59.5 37.3
DFW Mean T Max T Min T
Neutral 46.6 57.3 35.9
El Niño 46.8 56.8 36.7
La Niña 48.3 59.1 37.4
1971-2000 46.7 56.9 36.5
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Winter Minimum Temp(58 winters - 1950-2007)
DFW Neutral El Niño La Niña
≤ 7⁰F (14%) 5 (23%) 1 (6%) 2 (11%)
≤ 15⁰F (53%) 15 (68%) 6 (33%) 10 (53%)
Waco Neutral El Niño La Niña
≤ 11⁰F (20%) 7 (32%) 3 (17%) 2 (11%)
≤ 17⁰F (43%) 14 (63%) 6 (33%) 6 (32%)
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Average Minimum Tempfor the Winter (Dec-Feb)
(1950-present)
DFW Neutral El Niño La Niña
12 coldest 8 3 1
10 warmest 1 5 4
Waco Neutral El Niño La Niña
11 coldest 6 4 1
11 warmest 0 5 6
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Winter of 1989-90(ENSO neutral)
2nd coldest December (1983 coldest)• DFW – over 3 consecutive sub-freezing
days• December 23, 1989 … DFW -1⁰F, ABI -7 ⁰F
-4⁰F ACT, -7⁰F SPS, +1⁰F GGG
• devastating to vegetation
5th coldest February, but January 7.7⁰F above normal!
Winter 1989-90 (December-February) temperatures• mean 1.4⁰F above normal• average max 3.0⁰F above normal• fewer freezes than normal
2nd coldest December (1983 coldest)• DFW – over 3 consecutive sub-freezing
days• December 23, 1989 … DFW -1⁰F, ABI -7 ⁰F
-4⁰F ACT, -7⁰F SPS, +1⁰F GGG
• devastating to vegetation
5th coldest February, but January 7.7⁰F above normal!
Winter 1989-90 (December-February) temperatures• mean 1.4⁰F above normal• average max 3.0⁰F above normal• fewer freezes than normal
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Other Sub-Zero Winters
January 31, 1949• DFW -2⁰F, Waco -5⁰F• 1948-1949 ENSO neutral (JMA)
January 18, 1930• DFW -1⁰F, Waco -1⁰F• 1929-1930 El Niño (JMA)
February 12, 1899• DFW -8⁰F• 1898-1899 ENSO neutral (JMA)
January 31, 1949• DFW -2⁰F, Waco -5⁰F• 1948-1949 ENSO neutral (JMA)
January 18, 1930• DFW -1⁰F, Waco -1⁰F• 1929-1930 El Niño (JMA)
February 12, 1899• DFW -8⁰F• 1898-1899 ENSO neutral (JMA)
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Average Minimum Tempfor the Winter (Dec-Feb)
(1950-present)
DFW Neutral El Niño La Niña
12 coldest 8 3 1
10 warmest 1 5 4
Waco Neutral El Niño La Niña
11 coldest 6 4 1
11 warmest 0 5 6
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ENSO NeutralWinter Precipitation
ENSO neutral and winter precipitation - little significant correlation
Of 14 sites analyzed, 6 show weak dry signal• Graham most significant (both DJF and
JFM)• DJF – DFW, Denton, Forestburg• JFM – Greenville, Lampasas
NONE show wet signal
ENSO neutral and winter precipitation - little significant correlation
Of 14 sites analyzed, 6 show weak dry signal• Graham most significant (both DJF and
JFM)• DJF – DFW, Denton, Forestburg• JFM – Greenville, Lampasas
NONE show wet signal
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CPC Outlook Inputs
1. El Niño/Southern Oscillation (ENSO)2. trends• temperature – 10-year mean• precipitation – 15-year mean
3. Madden-Julian Oscillation (MJO)4. North Atlantic Oscillation (NAO)5. Pacific Decadal Oscillation (PDO)6. soil moisture anomalies7. statistical tools8. dynamic models9. objective skill analysis
1. El Niño/Southern Oscillation (ENSO)2. trends• temperature – 10-year mean• precipitation – 15-year mean
3. Madden-Julian Oscillation (MJO)4. North Atlantic Oscillation (NAO)5. Pacific Decadal Oscillation (PDO)6. soil moisture anomalies7. statistical tools8. dynamic models9. objective skill analysis
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Current CPC Winter Outlook
Nov/Dec/Jan Temperature Outlook
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Current CPC Winter Outlook
Dec/Jan/Feb Temperature Outlook
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Current CPC Winter Outlook
Jan/Feb/Mar Temperature Outlook
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Current CPC Winter Outlook
Nov/Dec/Jan Precipitation Outlook
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Current CPC Winter Outlook
Dec/Jan/Feb Precipitation Outlook
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Current CPC Winter Outlook
Jan/Feb/Mar Precipitation Outlook
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Precipitation Departures
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Fire Danger!
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Summary
ENSO neutral conditions are expected to continue throughout the upcoming winter
ENSO neutral winter composites show…• mean temperatures near normal• generally lower than normal minimum
temps• extreme cold outbreaks more common• little precipitation correlation
CPC outlooks show…• warm winter trend – can mask extreme
events!• little precipitation signal – thus drought a
concern
ENSO neutral conditions are expected to continue throughout the upcoming winter
ENSO neutral winter composites show…• mean temperatures near normal• generally lower than normal minimum
temps• extreme cold outbreaks more common• little precipitation correlation
CPC outlooks show…• warm winter trend – can mask extreme
events!• little precipitation signal – thus drought a
concern
