OVERVIEW:  Our projection for September was maintained this week for a near to slightly above average (0.0°F to +2.0°F) temperature departure for the month as a whole. We are starting off the month several degrees above average, but some notable slightly below average stretches are expected over the remainder of the month to balance things a bit. October projections were also maintained this week for a near average (-1.0°F to +1.0°F) temperature departure using long term climate guidance and global observation trends.

• Seasonal changes are going to be become more noticeable in the weeks ahead as we continue to lower average highs/lows, and that downward process accelerates beyond mid-September to about a 3.0°F drop per week. The extreme heat is likely behind us, but there will still be some warmer days yet that reach into the 80s up through just past mid-September. Climate models have gone against the idea of a warmer start to October and are instead indicating a slightly cooler stretch for at least the first few days of the month, followed by generally near average conditions thereafter. 
   
• The Madden-Julian Oscillation (MJO) is currently in the Circle of Death (COD) or NULL phase, and largely remain there through early October. In this case, the El Niño background state and other teleconnections will be running the pattern for awhile. Hurricane activity should remain limited with a strong El Niño increasing Atlantic shear despite reaching the peak of Atlantic hurricane season September 10th. In fact, as of today, this is the longest we’ve gone without an Atlantic Basin hurricane in recorded history, which is to say since 1966 in the modern satellite era. Remarkable nevertheless.
  
  
• A composite average of the SST departures in the ENSO regions places it in moderate to strong El Niño territory currently. From west to east across the Pacific, the Niño 4 (west-central Pacific) is currently the “coolest” region at +0.9°C, whereas the Niño 3.4 region (east-central Pacific) is currently at +2.9°C. The eastern regions of Niño 3 (east-central Pacific) is currently +3.8°C, and Niño 1+2 region (near the Peruvian coast) is at +4.8°C as of September 9th. The current El Niño Summer is likely to be followed by a near-record strong El Niño Fall, and is currently East-based.
  
  

Average high temperatures are currently in the 77-81°F range from north to south across our coverage region, which is about 2°F lower than at this point last week. Temperatures will continue to slowly drop off through mid-September, then the drop off accelerates downward beyond mid-month. Any above or below average stretches listed in the outlook will be relative to seasonal norms at that time, and it is important to note that cooler/warmer periods will be relative to the time of year we are talking about. For example, the transient slightly above average temperatures listed for the September 16th-18th period features highs in the lower 80s for perhaps the past time this year, coming at a time when average highs are in the mid to upper 70s. Use the average highs/lows chart below providing transparency for what average temperatures are expected to be at each corresponding location through November 1st.

Our September projection was maintained this week for a near to slightly above average (+0.0°F to +2.0°F) temperature departure. October projections were also maintained this week for a near average (-1.0°F to +1.0°F) temperature departure using long term climate guidance and global observation trends, and preliminary indications of a cooler first few days of the month.