Groundhog prediction may be correct - an early spring!
By Rod Hill on 2024-02-06
Let me begin by saying near normal temperatures with below normal rainfall is in the forecast for Portland and Salem through the first 15 days of February. The normal climate high for the period in the mid to north Willamette Valley is low 50s, meaning near normal is pretty comfortable. Also, normal to below normal rainfall will seem quite dry when compared to the 18.16" of total precipitation that fell in Portland from December 1st through the month of January. Total precipitation the last two months is 7.36" above normal or nearly 170% of normal, making for an extra 6 weeks of rainfall.
The NOAA outlook for the back half of February, February 17 through March 1st, puts the Pacific Northwest in the highest confidence zone to see above normal temperatures, along with drier than normal rainfall. The outlook coupled with current forecast projections leads to the conclusion that Portland has seen the last of bitterly cold winter weather this season.
Here is a weather model temperature anomaly for the first week of March showing above normal mean temperatures
for much of Oregon and Washington as March begins. The numbers would suggest a number of days with either low temps in the mid 40s to 50 degrees and or highs warming into the 60s. The American CFS weather model shows positive temperature departures of +3 to +7 in our local region.
Before warm weather lovers get overly excited, there are signs the back half of March will turn cooler and wet. If true, the timing of the colder than normal air would be chilly and likely not the bitter cold we saw with the January Arctic air mass when Portland experienced three days of high temperatures in the 20s. Record cold high temperatures in mid- March for the Rose City are generally in the 40s.
A timeline of warming climate numbers as spring approaches shows Portland's normal high temperature currently at 50 degrees, warming to 54 March 1st and to 57 degrees the first day of Spring. By April 1st, Portland's normal daily high temperature is 59 degrees. The average final spring freeze in Portland is around April 1st, while parts of the valley can see freezing numbers into early May.
The current El Nino cycle, connected to our mild December and recent heavy rains in California is expected to weaken into Enso-Neutral conditions during the month of April. NOAA is projecting a return to La Nina conditions this summer and into the fall season.
Meteorologist Rod Hill
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