Hot and Dry

The western US is no stranger to heat. But even so, levels of heat can reach a point where it’s hotter on a certain date than it has been in the past. That sort of heat is on tap today for the Central California valley.

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Many, if not all, locations in this valley will soar into the triple digits today and challenge daily record highs.

Some of these are fairly long-standing records, too.

  • Sacramento’s current record is 100 degrees set in 1951. The forecast is 102 degrees.
  • Fresno’s current record is 102 degrees set in 1890. The forecast is 103 degrees.
  • Redding’s current record is 103 degrees set in 1982. The forecast is 103 degrees.
    • While this one isn’t quite as long-standing as the rest, it’s still an impressive level of heat.

For many cities in this region, this will be the second consecutive day of (potential) record heat. Fortunately, it will also be the last as temperatures gradually decrease moving toward and into the weekend.

 

Today’s heat unfortunately combines with another threat: fire weather.

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Though not considered an “elevated” or “critical” threat at this time, a Red Flag Warning is still in effect for the northern half of the valley. Gusty winds of up to 30 mph and dry conditions with relative humidity potentially dipping below 10% will lend to the rapid spread of any fires that start.

It’s no secret that this region has been incredibly dry since a (very brief) wetter-than-average period at the beginning of the year.

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As I discussed last year during the Pacific Northwest heatwave, dry ground/a dry atmosphere heats up more than one with excess moisture available. Some of the sun’s energy is meant to go toward evaporation, fulfilling that part of the water cycle. When there is no excess moisture to evaporate, that energy then goes into heating the ground and air, resulting in warmer-than-average temperatures. The lack of rain and on-going drought is no doubt contributing to today’s potential record highs.

Unfortunately, there seems to be little to no chance at precipitation through the end of the month, according to medium-range outlooks.

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For now, a better signal for rain develops in early June, albeit briefly. This, of course, can change but any rain is welcome rain when you’re in drought – as long as it actually materializes.

 

 

 

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