Nino SSTA Neutral Despite Onset of La Nina Announcement by NOAA
10/14/2025, 9:21 am EDT
Climate Impact Company U.S. Medium Range Report
Issued: Wednesday October 15, 2025
Highlight: Briefly cooler East/Southeast days 6-10, otherwise warm.
Chart of the day: The warm oceans, causal to warm medium range forecasts.
Discussion: Day-to-day, medium/extended-range forecasts in North America are usually warmer than normal. A leading catalyst to that regime is much warmer than normal global ocean surface, most apparent in the middle latitudes beneath the prevailing upper-level westerlies that drive out climate. Maine heatwaves have increased dramatically in the middle latitudes particularly in recent years. The latest Climate Impact Company marine heatwave assessment will be issued later today.
Medium-range 6-10 Day Forecast Valid October 20-24, 2025 (24-hour change right)
Discussion: Taking longer nowadays to produce a cool pattern in the East U.S., the current -NAO regime finally cools the East in the 6-10-day period, particularly the Southeast.
Medium-range 11-15 Day Forecast Valid October 25-29, 2025 (24-hour change right)
Discussion: Persistence wins out in the 11-15-day period as broadening anomalous warmth regenerates while the cool bias remains on the West Coast.
U.S. Medium-range Precipitation Forecast
Discussion: Storminess shifts into the Northeast U.S. in the 6-10-day period and back to the Northwest States in the 11-15-day forecast. Note the wet bias across the Caribbean Sea where a late season tropical system forms.
Days 16-20 Extended range Temperature Forecast valid October 30-November 3, 2025
Discussion: The warm pattern does not budge in the extended range. The Northwest and Florida encounter significant precipitation.