The following are two examples which shows how TLI
is routinely used to accurately update terminal aerodrome forecasts within
NWSO Melbourne's area of aviation responsibility. On this day, TLI was
exploited by both the AMU and the duty forecasters during the composition
of three TAF amendments (AMD) - two were issued for the Orlando International
Airport (KMCO) and one was issued for Daytona Beach Airport (KDAB).
The subsequent SPECI observation from 2017Z showed that a thunderstorm began at 2016Z.
Continued examination of radar and lightning data showed additional thunderstorms had developed and were increasing in coverage and intensity between 5 and 10 miles to the west and southwest of KMCO by 2035Z. Based on this, the TAF was immediately updated to show prevailing weather of: winds out of the east 100 degrees at 12 knots, visibility of 5 statue miles from thunderstorms with moderate rain, few clouds at 1,000 feet and broken cumulonimbus clouds at 4,500 feet, with the following temporary condtions until 22Z: wind out of the SE, 150 degrees at 15 gusting to 20 knots, visibility 1 statute mile in a thunderstorm with heavy rain, and broken cumulonimbus clouds at 1,500 feet.
The METAR from 2053Z showed conditions had deteriorated
to: winds 130 at 14 gusting to 22 knots, visibility 3 statue miles in a
thunderstorm with heavy rain, few clouds 8 hundered feet, scattered clouds
at 2,800 feet and broken cumulonimbus clouds at 5,000 feet. A SPECI was
taken at 2122Z to end the thunderstorm at that time.
TAF
KMCO 237120Z 231818 13008KT P6SM FEW035 TEMPO 1821 4SM SHRA BKN025
FM0000....
TAF
KMCO 231841Z 231918 13008KT P6SM FEW040 TEMPO 1921 3SM TSRA
BKN025CB
FM0000....
TAF
KMCO 232034Z 232118 10012KT 5SM TSRA FEW010 BKN045CB TEMPO
2122
15015G20KT 1SM +TSRA BKN015CB
FM0000....
METAR KMCO 231753Z 14007KT 10SM FEW042 SCT050 BKN300.....
METAR KMCO 231853Z 00000KT 10SM SCT047CB BKN300....RMK CB DSNT E
TCU NE-SE
METAR KMCO 231953Z 08014KT 10SM BKN046CB BKN300....RMK CB VCSH E-S
SPECI KMCO 232017Z 09008KT 10SM TS SCT040CB SCT120
BKN300....RMK TSB16
TS SE MOV W CB VCSH E-S
SPECI KMCO 232024Z 09008KT 10SM TS FEW008 SCT048CB
BKN120....RMK TSB16
TS SE MOV W CB VCSH E-S
METAR KMCO 232053Z 13014G22KT 3SM +TSRA BR FEW008 SCT028 BKN050CB....
RMK TSB16RAB36 TS OVHD-S MOV W
CB E-SW VSB S 2
SPECI KMCO 232111Z 12008KT 10SM -RA FEW012 SCT028CB OVC150....RMK
TSE21
TS DISPTD CBS TCU DSNT N
Similarly, the 18Z TAF for KDAB was amended at 1942Z due to developing thunderstorms over southern Volusia County (not shown). These storms were forecast to begin affecting the airport at 2030Z, accompanied by rainshowers in the vicinity (but not at the airport), scattered cumulonimbus clouds at 2,500 feet, with a temporary condition of no significant weather (NSW).
The series of METARs from KDAB shows that a thunderstorm without rainfall
began at 2033Z and ended at 2053Z.
TAF
KDAB 231720Z 231818 09006KT P6SM SCT025 BECMG 1920 09010KT FEW025
FM0000....
TAF
KDAB 231942Z 232028 11008KT P6SM SCT025 SCT100
FM2030 11010KT P6SM TS VCSH SCT025CB BKN100 TEMPO 2123 NSW
FM2300....
METAR KDAB 231753Z 03004KT 10SM FEW022CB....RMK CB S W-NW MOV NW
METAR KDAB 231853Z 11007KT 10SM SCT022CB SCT049 SCT090....RMK CB
S-W
MOV NW CB DSNT E-SE
METAR KDAB 231953Z 07010KT 10SM FEW025CB SCT040 SCT090....RMK CB
N S-SW
MOV NW
SPECI KDAB 232033Z 08008KT 10SM TS SCT019CB SCT038 SCT047....RMK
TSB33 TS
OVHD MOV NW LTGIC OVHD CB W MOV NW
METAR KDAB 232153Z VRB06KT 10SM FEW019CB SCT100...RMK TSB33E53
CB SW-W MOV NW