Long Range (7+ Days)

CPC 8-14 Day Temperature Forecast

CPC 8-14 day

CPC 8-14 Day Analog Forecasts

CPC 8-14 Day Analog


North American Multi-Model Ensemble 1 Month Lead Time Precipitation Anomalies Forecast

NCEP

NMME 1 Month Lead Time For 2 Meter Temperature Anomalies 1-month

NCEP

Experimental North American Ensemble Forecast System 8 to 14 day

Temperature Anomalies

Experimental North American Ensemble Forecast System 8 to 14 day

500mb Height Anomalies

NAEFS

3 Month Average Temperature Outlook For Philadelphia

Probability of Exceedance Curve
weather.gov

Red line is the 3 month average temperature between 1981 and 2010. The latest 3 month period is shown above. Green line is expected temperature outlook as a percentage vs temperature. For example, there is a middle point of the green curve at 76 degrees, this equates to a 50% chance of exceeding that as an average temperature for the tri-monthly period of JJA. At the bottom edge of the curve, there is almost a 0 percent chance of exceeding an 80 degree average for the tri-monthly period. Generally, we are most likely to have an average temperature between 75 and 77 degrees. That includes daytime and night time temps.

Yearly Tri-Monthly Temperature Outlook for Philadelphia

Temperature Range Confidence Intervals
weather.gov

Down arrow represents upper range of 99% confidence interval and up arrow represents lower 99% range. So in this outlook we can see that JJA is expected to be between 72 and 80 with 99% confidence. This graph is primarily based on climotology factors.

Here is another with 90% confidence interval

Temperature Range Confidence Intervals

CFS Weekly Forecasts:

Weeks 1-4:
CFS Weekly

Monthly Forecasts

Climate Prediction Center Weekly + Monthly Outlook
NCEP
ECMWF Long Range
2m Temp Long Range
International Research Institute for Climate and Society
IRI
CanSIPS Monthly
CanSIPS
NMME
CPC NMME