Scientifically what is at fault for this significant increase in high temperatures over southern Oregen?

Question

May 13 (night) Showers 49° Precip. 40 %

May 14 AM Showers 75°/51° 30 %

May 15 Sunny 84°/57° 10 %

May 16 AM Clouds / PM Sun 92°/56° 20 %

May 17 Sunny 85°/53° 20 %

May 18 Mostly Sunny 79°/48° 20 %

May 19 Partly Cloudy 70°/43° 20 %

May 20 Partly Cloudy 65°/40° 20 %

May 21 Showers 65°/43° 60 %

May 22 Partly Cloudy 68°/43° 20 %

can anyone please give me an explaination for this? it would be much appreciated thank you

Answer 1

What is happening is over the next 2-3 days is an unseasonably large region of high pressure is building over the western U.S.   What happens when high pressure settles is that you have sinking air which prohibits rain.  You won't see any chance of rain until May 21st when the next low comes near.  Otherwise, you will have dry conditions from May 15th to May 21st.  The 20% chance of precip in the forecast is garbage (probably weather channel right?)

Anyway, as for high temps, you get warm air advection for one with high pressure setting up. You also get expanding air as what weathermen call the "heights".  The "heights" simply denotes the distance from one pressure to another in the atmosphere... when you have a larger number than normal, you will experience warmer temps (See physics and the relation between volume, pressure, and temperature)

This high pressure not only will bring above average high temps to Oregon, but look also for California (inner-portions) to set records this weekend.