PHOENIX -- Phoenix reached 113 degrees today, the hottest temperature so far this year, and it's not over yet. Excessive Heat Warnings are posted for metro Phoenix for Wednesday and Thursday.
The hottest days of the year, so far, are on tap for the Valley this week. We’re anticipating high temperatures to be in the range of 112-117 degrees both Wednesday and Thursday. We will probably set some record highs around the state and perhaps tie some records in the Valley.
A strong high pressure system is forecast to develop over the region this week, resulting in very hot temperatures by Wednesday. At the same time, monsoon moisture will slowly increase over the area with occasional cloudiness at times.
Increased moisture levels combined with several weak weather disturbances from Mexico are forecast to increase the chance of afternoon and evening showers and thunderstorms, mainly across the mountains of Arizona.
The best performing temperature guidance continues to predict the afternoon warm-up into near record breaking territory Wednesday and Thursday. This is despite model guidance of more convective debris clouds and slightly higher humidity levels.
Since there is a lot of variability in cloud forecasts -- and even precipitation chances -- and the best performing afternoon temperature guidance is still bullish on higher temperatures, the Excessive Heat Watch will continue for this time period. However, the Watch could be upgraded to a Warning if less cloud cover arrives to mitigate the warmth. Southeast California and Southwest Arizona will be in full sunshine for much higher afternoon temperatures.
It's not just the highs, it's also the duration. Wednesday most Valley locations will have triple-digit temps for 12+ hours #heatwarning— Royal Norman (@royalnorman) July 23, 2014