FPUS42 KMFL 251006 City Forecast for West Palm Beach, FL Issued Wednesday morning - Nov 25, 2009 .Wednesday... Thunderstorm, high 79, 90% chance of precipitation. .Wednesday night... Low 68, 80% chance of precipitation. .Thursday... Showers, high 79, 50% chance of precipitation. .Thursday night... Low 54. .Friday... High 68.