Dangerous, record-breaking heat will intensify across most of the central and eastern U.S this week. Heat indices will likely exceed 100 degrees. Severe thunderstorms are forecast from parts of the central High Plains into the Upper Midwest, and across parts of the Northeast. Critical fire weather conditions will continue across portions of the Four Corners and Great Basin. Read More >
Instructions for the proper application of the reference time designator
1. The designator specified in this table should be used to the greatest extent possible to indicate the reference time of data contained within the text of the bulletin.
2. When the table does not contain a suitable designator for the reference time, an alphabetic designator which is not assigned in the table should be introduced and the WMO secretariat notified.
| Designator |
|
Designator |
|
| A | Analysis (00 hour) | N | 39 hours forecast |
| B | 3 hours forecast | O | 42 hours forecast |
| C | 6 hours forecast | P | 45 hours forecast |
| D | 9 hours forecasts | Q | 48 hours forecast |
| E | 12 hours forecast | R | 54 hours forecast [48+6] |
| F | 15 hours forecast | S | 66 hours forecast [+12] |
| G | 18 hours forecast | T | 78 hours forecast |
| H | 21 hours forecast | U | 90 hours forecast |
| I | 24 hours forecast | V | 102 days forecast |
| J | 27 hours forecast | W | 114 days forecast |
| K | 30 hours forecast | X | 126 days forecast |
| L | 33 hours forecast | Y | 138 days forecast |
| M | 36 hours forecast | Z | 150 days forecast |
