Term
Criteria for Speci Windshift Visibility Runway Visual Range Tornado, funnel cloud, or waterspout Thunderstorm |
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Definition
(1) WIND SHIFT. Wind direction changes by 45 degrees or more in less than 15 minutes and the wind speed is 10 knots or more throughout the wind shift. (2) VISIBILITY. Surface visibility as reported in the body of the report decreases to less than, or if below, increases to equal or exceed: (a) 3 miles. (b) 2 miles. (c) 1 mile. (d) The lowest standard instrument approach procedure minimum as published in the National Ocean Service (NOS) U.S. Terminal Procedures. If none published, use 1/2 mile. (3) RUNWAY VISUAL RANGE (RVR). The highest value from the designated RVR runway decreases to less than, or if below, increases to equal or exceed 2,400 feet during the preceding 10 minutes. U.S. military stations may not report a SPECI based on RVR. (4) TORNADO, FUNNEL CLOUD, OR WATERSPOUT. (a) is observed. (b) disappears from sight, or ends. (5) THUNDERSTORM. (a) begins (a SPECI is not required to report the beginning of a new thunderstorm if one is currently reported). (b) ends. (6) PRECIPITATION. (a) hail begins or ends. (b) freezing precipitation begins, ends, or changes intensity. (c) ice pellets begin, end, or change intensity. (7) SQUALLS. When squalls occur. (8) CEILING. The ceiling (rounded off to reportable values) forms or dissipates below, decreases to less than, or if below, increases to equal or exceed: (a) 3,000 feet. (b) 1,500 feet. (c) 1,000 feet. (d) 500 feet. (e) The lowest standard instrument approach procedure minimum as published in the National Ocean Service (NOS) U.S. Terminal Procedures. If none published, use 200 feet. (9) SKY CONDITION. A layer of clouds or obscurations aloft is present below 1,000 feet and no layer aloft was reported below 1,000 feet in the preceding METAR or SPECI. (10) VOLCANIC ERUPTION. When an eruption is first noted. (11) AIRCRAFT MISHAP. Upon notification of an Aircraft Mishap unless there has been an intervening observation. (12) MISCELLANEOUS. Any other meteorological situation designated by the responsible agency, or which, in the opinion of the observer, is critical. |
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Term
| Tempeartures round how... |
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Definition
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Term
| Actual date and time of observation |
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Definition
time the last element of the observation was observed. The actual time of a SPECI shall be the time the criteria for the SPECI was met or noted. |
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Term
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Definition
METAR and SPECI in UTC Other documenation, either UTC or LST, with LST noting the correction factor to UTC |
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Term
Recency of Observed Elements at Manual Stations |
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Definition
Elements entered shall have been observed within 15 minutes of the actual time of the observation. Gusts and squalls shall be reported if observed within 10 minutes of the actual time of the observation. Observation of elements shall be made as close to the scheduled time of the observation as possible to meet filing deadlines, but in no case shall these observations be started more than 15 minutes before the scheduled time. |
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Term
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Definition
a. Local -- The transmission or delivery of a weather report to individual or groups of users in the service area of the weather station. b. Long-line -- The transmission of a weather report beyond the service area of the weather station. |
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Term
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Definition
Corrections shall be disseminated, as soon as possible, whenever an error is detected in a transmitted report. However, if the erroneous data has been superseded by a later report (with the same or more complete dissemination), it shall not be necessary to transmit the corrected report. Corrections transmitted shall consist of the entire corrected report. The original date and time of the report shall be used as the date and time in the corrected report. |
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Term
| When should a report be filed? |
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Definition
SPECIs shall be completed and transmitted, as soon as possible. METARs shall not be transmitted sooner than 10 minutes before their scheduled time. |
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Term
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Definition
| When transmission of an observation is delayed until time for the next regularly scheduled report, only the latest report shall be transmitted. In the record of observations, the remark FIBI (Filed But Impractical to Transmit) shall be appended in parentheses to the report that was not transmitted to indicate the report was not transmitted. The remark FIBI shall not be included in any local dissemination of the report. When a SPECI is not transmitted long-line, the later SPECI shall be transmitted long-line only when the overall change between the last transmitted report and the current report satisfies the criteria for a SPECI. If the SPECI is not transmitted long-line, the remark FIBI shall be appended to the report in the record of observations. The SPECI shall be disseminated locally. Reports of Volcanic Eruption shall be disseminated, by any means possible, regardless of the delay. |
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Term
| Reportable Visibility Values |
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Definition
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