Shortly after the 10:00 p. m. time signals, NAA sends weather bulletins in code letters and figures to express weather conditions along the eastern coast of the United States and the Great Lakes.
In case you have lost the key letters used they are given below:—
| U. S. W. B. | United States Weather Bureau |
| S | Sydney |
| T | Nantucket |
| DB | Delaware Breakwater |
| H | Hatteras |
| C | Charleston |
| K | Key West |
| P | Pensacola |
| B | Bermuda |
| Du | Duluth |
| M | Marquette |
| U | Sault Ste. Marie |
| G | Green Bay |
| Ch | Chicago |
| L | Alpena |
| D | Detroit |
| V | Cleveland |
| F | Buffalo |
The first three figures denote the barometric pressure in inches as (001 — 30.01) or (959 — 29.59). The fourth figure represents the direction of the wind:
| 1 | North | 5 | South |
| 2 | Northeast | 6 | Southwest |
| 3 | East | 7 | West |
| 4 | Southeast | 8 | Northwest |
| 0 | Calm. |
The last figure gives the force of the wind on the Beaufort Scale.
| Beaufort Scale of Wind Force. | ||
| Number and designation. | Miles per hour. | |
| 0 | Calm | 0—3 |
| 1 | Light air | 8 |
| 2 | Light breeze | 13 |
| 3 | Gentle breeze | 18 |
| 4 | Moderate breeze | 23 |
| 5 | Fresh breeze | 28 |
| 6 | Strong breeze | 34 |
| 7 | Moderate gale | 40 |
| 8 | Fresh gale | 48 |
| 9 | Strong gale | 56 |
| 10 | Whole gale | 65 |
| 11 | Storm | 75 |
| 12 | Hurricane | 90 and over |
Examples of Code:—
U. S. W. B. S 00355 T 93472 United States Weather Bureau Sydney. 30.03, south, fresh breeze, 28 miles per hour; Nantucket, 29.34, west, light breeze, 13 miles per hour.
Wind force greater than 9 is given by a word instead of figures.