A Brief History of Weather Forecasting. The Beginning: Weather Sayings. "Red Sky at night, sailor\'s delight. Red sky in the morning, sailor take warning." "Mare\'s tails and mackerel scales make tall ships take in their sails." "Clear moon, frost soon." .
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Cleveland Abbe (“Ol’ Probabilities”), who led the establishment of a weather forecasting division within the U.S. Army Signal Corps,
Produced the first known communication of a weather probability to users and the public.
Professor Cleveland Abbe, who issued the first public
“Weather Synopsis and Probabilities” on February 19, 1871
Cleveland Abbe released the first public weather forecast on September 1, 1869.
Following the signing by President Ulysses S. Grant of an authorization to establish a system of weather observations and warnings of approaching storms, on February 19, 1871, Abbe issued the first “official” public Weather Synopsis and Probabilities based on observations taken at 7:35 a.m.
"Synopsis for past twenty-four hours; the barometric pressure had diminished in the southern and Gulf states this morning; it has remained nearly stationary on the Lakes. A decided diminution has appeared unannounced in Missouri accompanied with a rapid rise in the thermometer which is felt as far east as Cincinnati; the barometer in Missouri is about four-tenths of an inch lower than on Erie and on the Gulf. Fresh north and west winds are prevailing in the north; southerly winds in the south. Probabilities [emphasis added]; it is probable that the low pressure in Missouri will make itself felt decidedly tomorrow with northerly winds and clouds on the Lakes, and brisk southerly winds on the Gulf."
One such equation is Newton’s Second Law:
F = ma
Force = mass x acceleration
Mass is the amount of matter
Acceleration is how velocity changes with time
Force is a push or pull on some object (e.g., gravitational force, pressure forces, friction)
This equation is a time machine!
Using a wide range of weather observations we can create a three-dimensional description of the atmosphere… known as the initialization
National Weather Service
The 1938 Hurricane was basically unforecast
gives us information
Based on Geostationary Weather Satellites
As the grid spacing decreased to 15 km and below… it became apparent that many of the local weather features could often be simulated and forecast by the models.
Forecaster at the Seattle National Weather Service Office
Example: too much precipitation on mountain slopes
This is particularly a problem for the Pacific Northwest, because we are downstream of a relatively data poor region…the Pacific Ocean.
At 4 PM
3 March 1999: Forecast a snowstorm … got a windstorm instead
The problem of initialization should lessen as new observation technologies come on line and mature.New ways of using or assimilating the data are also being developed.
The Thanksgiving Forecast 2001
42h forecast (valid Thu 10AM)
SLP and winds