Indiana Braces for Major December Cold as New Data Shows Below-Average Temperatures Driven by Negative WPO Shift

INDIANA — New long-range data shows Indiana heading into one of its coldest December stretches so far this season, as powerful atmospheric signals continue trending toward a sharply colder pattern across the central and eastern United States. The latest maps show widespread purple and deep blue temperature anomalies, indicating temperatures running 10 to 20 degrees below normal in upcoming days.

At the center of this shift is a strongly negative West Pacific Oscillation (WPO), which historically correlates with Arctic air flooding into the Midwest.

Models Continue Trending Colder as December Pattern Intensifies

Meteorologists have noted that the long-range guidance has been “flipping colder and trending colder” with each new run.
The large-scale temperature anomaly map shows:

• Indiana fully engulfed in deep cold anomalies
• Broad negative temperature departures stretching from the Dakotas to the Appalachian region
• High confidence in below-normal temperatures due to multi-model agreement

These signals suggest a durable cold pattern rather than a brief cooldown.

Negative WPO: The Driving Force Behind the Cold Surge

The WPO ensemble chart reveals an aggressive downward dip beginning around December 11–13, with values plunging as low as –3 to –4, a historically strong cold indicator.

A negative WPO typically produces:

• A strengthened Arctic high-pressure system
• Southward displacement of polar air
• Enhanced cold delivery into the Midwest and Great Lakes
• Suppression of warm Pacific influence

Simply put: When the WPO drops this low, Indiana usually turns much colder.

Temperature Outlook: Well Below Average With Multiple Cold Days Ahead

Based on current data, residents should prepare for:

• Significantly below-average daytime highs
• Several nights of potential single-digit wind chills
• A sharply colder second week of December compared to seasonal norms

While snowfall potential is not the main feature of this pattern, the cold air will be more than enough to support snow if any storm systems approach later in the month.

Is Snow Expected? Only Light Chances for Now

The dataset focuses mainly on temperature patterns, not storm systems.

Current indications show:

• No major winter storm signal yet
• Possibility of light snow events if northern-stream disturbances pass through
• Increasing chances for snow later in December if the cold persists

Meteorologists emphasize that the persistent cold pattern increases the likelihood of impactful snow sometime later this month, even if not in the immediate forecast.

What This Means for Indiana Residents

With temperatures trending sharply colder, residents may need to prepare for:

• Heavier heating demand
• Impacts on livestock and agriculture
• Potential icy mornings
• Cold-sensitive pipes in rural areas

This setup is classic for mid-December Arctic intrusions affecting the Midwest.

How are you preparing for Indiana’s deepening December cold pattern? Share your thoughts and stay updated with the latest forecasts at WaldronNews.com.