During the past week Sacramento has experienced the coldest overnight temperatures since December of 1990. Lows have dipped into the upper teens and very low 20's at almost all Valley reporting stations, with the exception of the "official" Downtown Sacramento station.
This Downtown reading is actually taken on the roof of the Post Office Building and is many stories above the ground. The airmass that has brought the cold temperatures is a very shallow, dense layer of air that reforms every night after sunset and extends only a short distance above the ground - an "inversion". That is, temperatures are colder near the ground than higher up. As a result, temperatures taken at all airport and suburban locations are running 5-10 degrees colder than the Downtown rooftop location.
Unfortunately, almost all media forecasts - that is television, radio and newspaper reports, use this Downtown reading. Therefore, the temperature forecasts going out to the public for "Sacramento" are really for the Post Office roof and have not been accurate for determining whether a freeze will occur near the ground - that is, within the first 5-10 feet above ground where most pipes, delicate plants, and cold-sensitive pets are found. Decisions about the homeless are also being based on this "official" forecast, and these individuals certainly don't live on rooftops.
In the past couple of nights temperatures continue to fall to or below freezing in most of the Sacramento Valley and almost all of the San Joaquin Valley, yet, despite the obvious cold, the media and the National Weather Service continue to over-forecast the lows by 5-10 degrees.
Unfortunately, the National Weather Service continues to use this rooftop reading as the "official" Sacramento temperature, despite the fact that fully 99% of all people in the metro region will experience readings more like those reported from the airports - Executive or International.
And, despite the obvious discrepancy between the rooftop readings and thousands of backyard thermometers and all the airport readings, almost all Sacramento television and radio weathercasters continue to miss the low forecast by as much as 10 degrees night after night.
This is the most upsetting and ridiculous series of forecast errors I have ever witnessed in my 20 years of forecasting and measuring the weather in Sacramento and I hope you will use common sense about this critical situation and base your decisions on the airport readings and NOT the Downtown rooftop reading.
Why doesn't the National Weather Service realize the obvious problem and do something about it? Why doesn't the NWS forecast the temperatures for locations where people actually live? Why don't the media weathercasters have the common sense to do the same? Beats me.
The situation appears to be a total refutation of common sense and responsibility. I call these forecasts "criminally negligent" because untold amounts of money are being lost due to damage to plants, pipes and fruit trees, and yet the ridiculous forecasts continue.
If you have noticed the situation or have been affected by these erroneous forecasts by either the National Weather Service or the media I urge you to make your thoughts known by calling or writing the appropriate television or radio News Directors or the National Weather Service, or your congressional representatives.
There is no reason why we should be paying taxes to the government so that they can give us a forecast of low temperatures night after night that is too high by 10 degrees when pets, pipes, and plants are at stake.
You can be assured that I will attempt to forecast the weather for the locations where people live and not for rooftops. And, if freezing temperatures have an effect on your life, make sure you become aware of which media concerns and forecasters come up with the correct numbers - verify, compare and be aware.
Tom Loffman
Meteorologist