By
Gp Capt (Dr) B Nandi
- Introduction
Leh is situated in Indus valley in Ladhak, a difficult terrain to access by road. Though there are two highways one from Srinagar and other from Manali. Air way is boon for Leh. Kushok Bakula Rinpoche Airport is a public use airport located 2 km southwest of Leh, a town in the state of Jammu and Kashmir, India. It is one of the highest airports in the world at an elevation of 3,256 m (10,682 ft) above mean sea level. With Runway 07 only for Approach and Runway 25 for Departure, makes Leh a unidirectional runway (where take-off and landing happen in the same direction). Strong surface wind, during the summer months, of the order of 30-40kts over this runway during afternoon hours is extremely challenging for aircraft to land, if not impossible. Intend to understand the reason for such strong wind so that predictability can be improved.
2. Topography.
Topography plays a major role in formation of strong wind. In figure 1, the topography is provided.
The orientation of this valley is Northwest to Southeast with very high hills to the Northeast and Southwest giving feature like gorge in little larger scale. Figure 2 provides the runway location and orientation.
Airport is situated north of river Indus and south of Srinagar-Ladhak Highway. West of Manali-Ladhak Highway, 2 km south of town.
3 Approach of aircraft.
This unidirectional runway has very peculiar approach. The below figure 3 will be able to explain it
Aircraft enters from east and turns around inside the valley and makes approach from 07. Predominantly Northwesterly surface wind makes it a tailwind landing airport. That is why landing poses a challenge. If winds are strong it makes landing impossible.
4 Gap flow
The air flow at 500hPa above the terrain mostly light being in frictional layer. Leh valley wind is easterlies/southeasterlies during late night to morning hours and westerly/northwesterlies during afternoon to night. During transition period from easterly to westerly, it is light and variable.
The flow through the valley is mostly parallel to the gap. That is Northwesterly (270-320 direction) or Southeasterly (110 to140 direction). Northwest of this Indus Valley ends near Sanjak. One valley goes to north, towards Dah and other valley south, towards Kargil. There is a North-south oriented high hill range (5095m) near Garkon within short span it slopes down to Leh valley to 2700m near Sanjak (Figure 4 & 5). This N-S mountain ridge blocks the valley mouth at western end and this is the most important feature in controlling the wind flow over valley. The second most important feature is the slope of the valley – western end near Sanjak elevation is 2100m and near airport elevation is 3256m. A slope of 1156m.
5. Upslope/downslope wind
Eastern side, near airport, is colder due higher elevation and western side, near Sanjok, is warmer due lower elevation. Colder heavier air downslopes from east to west like katabatic wind giving rise to easterly wind and during the day reverse happens, warmer lighter air upslope to east like anabatic wind, giving rise to westerly wind. Easterly wind strength is maximum during early morning hours when east-west temperature difference is maximum, westerly wind strength is maximum during afternoon hours when east-west temperature difference is maximum.
6. Mountain wind
The strong westerlies of mid troposphere rise over the North-South mountain ridge, near̥ Garkon crosses over the mountain and slopes down to enter the valley mouth near Sanjok. This wind over the valley mouth Leh at western end is mostly the wind which was over the mountain ridge. So the column of wind over the mountain ridge is indicative of wind flow over the valley. That is, the wind flow in meteorological chart of 500hpa, 400hPa and 300hPa will indicate the bottom 4km column of air flow over mountain ridge and in turn at valley mouth.
7. Ultimate wind at valley
The final wind over Leh valley has two contributor
- Up slope/down slope wind
- Mountain wind
Usually 500hPa wind is light as it is close to frictional layer at the N-S ridge elevation. So Leh valley wind (upslope/downslope) does not get much affected. Leh wind to get affected needs turbulent mixing of lower column of air in the valley. Turbulence is dominated by three factors.
- Shear induced
- Terrain induced
- Thermal mixing
If shear is large (we will judge by the shear in 400hPa- 300hPa layer above N-S ridge) gusty wind will start from the morning itself as long as the 400hPa wind is strong. If not but 300hPa wind is strong it will start slightly later but in the morning as terrain induced turbulence is omnipresent. Thermal turbulence will bring higher wind and higher gustiness in the afternoon hours continuing till evening.
Generally, winds at 5000m and above being westerly wind sloped down to eastern side of this North -South range to the valley mouth of Leh-valley and flows down the gorge like channel of the valley. On a day of strong westerly 30kt or more at 300hpa the wind over the valley is NWly. On a weaker wind day wind after crossing the N-S hill is also weak and the local wind take prominence. During night and early morning Leh valley is colder at an elevation of 3256m than the valley mouth at Sanjak (2700m). During night drainage wind of cold air blows down to Sanjak as SEly wind. This being ageostrophic wind it oscillates with frequency of nearly 23h (2*3.14/f (f is Coriolis parameter)). Starting from mid night it peaks near morning after 5 hours 45 minutes. After sunrise temperature starts rising. Rise is more at lower altitude of Sanjak. So with the progress of the day up slopes warm wind from west starts blowing through the valley. Once again this is also ageostrophic wind and oscillates with frequency of nearly 23h (2*3.14/f (f is Coriolis parameter)). Starting after sunrise say 2 or 3 UTC, the peak of the wind can be seen by 8 or 9 UTC, after quarter of oscillation period. Westerly wind strength can easily go up to 30-40kts in the afternoon. During transition to westerly to easterly or vice versa winds in the valley is light and variable.
8 Synoptic Ridge in wind
Ridge can be seen over North India and adjoining Pakistan on 02 May2022 at 500hPa and 300hPa. Winds over western end of leh valley was NNEly. So no westerlies were flowing over the N-S ridge and then to Sanjak and thus to Leh valley. Ridge moved away and strong westerly started over Leh valley on 03May2022.
Ridge was over North India and adjoining Pakistan on 17 APR2022 at 500hPa and 300hPa. Winds over western end of leh valley was NNWly. So no westerlies were flowing over the N-S ridge and then to Sanjak and thus to Leh valley. Ridge moved away and strong westerly started over Leh valley on 18APR2022.
- VILH 180900Z 34012KT 6000 SCT070 21/M16 Q1025 NOSIG=
- VILH 180930Z 32006G19KT 6000 FEW060 SCT070 20/M17 Q1024 TEMPO 32015G25KT=
- VILH 181230Z 28013KT 6000 FEW060 SCT070 17/M15 Q1024 TEMPO 29015G25KT=
- VILH 181300Z 30012G22KT 6000 FEW060 SCT070 17/M15 Q1024 TEMPO 32025KT=
- VILH 181330Z 28012KT 6000 FEW060 SCT070 16/M14 Q1024 TEMPO 32025KT=
Trough was over North India and adjoining Pakistan on 22 APR2022 at 500hPa and 300hPa. Winds over western end of Leh valley was SWly. So no westerlies were flowing over the N-S ridge and then to Sanjak and thus to Leh valley. Trough moved away and strong westerly started over Leh valley on 22APR2022 around 1300UTC.
- VILH 221300Z 30011G21KT 6000 SOCC SCT060 SCT120 14/M11 Q1020 TEMPO 30015G25KT=
- VILH 221330Z 30017G27KT 6000 SCT060 SCT120 12/M09 Q1020 NOSIG=
6.Conclusion
The characteristic features of wind over Leh is due to the topography, valley orientation, high hill on the Northeastern side and Southwestern side of valley, North-South hill ridge over the western mouth of the valley. All together makes a nice gorge like channel for wind flow. Wind blows along the channel of the valley either from east to west or from west to east. How it will blow depends on the upper tropospheric flow at 500hPa and above, the height of the N-S hill ridge is being 5095m. If there is strong westerly at 500hPa and above, it will enter the valley from Sanjak end as westerly and whole day Leh wind will be westerly peaking during afternoon as very strong wind due ageostrophic oscillation.
On weaker wind day at 500hpa the absence of westerly in the channel of valley, the local heating and slope of the valley will dominate to provide easterlies during night to early morning and westerlies during day. Peaking in wind will depend on the initial strength of the wind so that oscillation by ageostrophic wind has large amplitude. This wind acceleration starts oscillating the ageostrophic wind as in nocturnal jet formation, can make the wind two to three times the geostrophic wind. Following are characteristic feature of Leh wind,
- This is summer phenomenon –March to September.
- During summer, ground heating/cooling is prominent and slope of the valley controls the down slope/up slope wind. Strengthening of wind is by acceleration producing the ageostophic oscillation.
- On day of clouding, strong gusty wind does not take place as ground heating is not prominent.
- Approach of Synoptic ridge or trough over the valley inhibits strong surface wind formation as westerly wind hardly enters the valley mouth in the west.
Appendix-1
Leh METARs on 02May2022
VILH 011800Z 29008KT 6000 FEW070 16/M14 Q1022 NOSIG=
VILH 011930Z 31005KT 6000 FEW070 15/M13 Q1022 NOSIG=
VILH 012030Z 29008KT 6000 FEW070 13/M12 Q1022 NOSIG=
VILH 012130Z 30005KT 6000 FEW070 12/M12 Q1023 NOSIG=
VILH 012230Z VRB02KT 6000 FEW070 09/M11 Q1023 NOSIG=
VILH 012330Z VRB01KT 6000 SKC 07/M10 Q1024 NOSIG=
VILH 020000Z VRB02KT 6000 SKC 07/M12 Q1024 NOSIG=
VILH 020130Z 00000KT 6000 SKC 08/M11 Q1026 NOSIG=
VILH 020135Z 00000KT 6000 SKC 08/M11 Q1026 NOSIG REMKS ALL PASSES CLEAR=
VILH 020200Z VRB01KT 6000 SKC 10/M09 Q1026 NOSIG=
VILH 020230Z VRB02KT 6000 SKC 13/M10 Q1026 NOSIG=
VILH 020300Z VRB01KT 6000 SKC 16/M12 Q1026 NOSIG=
VILH 020330Z VRB02KT 6000 SKC 17/M11 Q1026 NOSIG=
VILH 020400Z VRB02KT 6000 SKC 18/M11 Q1026 NOSIG=
VILH 020430Z VRB02KT 6000 FEW070 20/M14 Q1026 NOSIG=
VILH 020500Z VRB02KT 6000 FEW070 20/M15 Q1025 NOSIG=
VILH 020530Z 11004KT 6000 FEW070 23/M17 Q1025 NOSIG=
VILH 020630Z 30003KT 6000 FEW070 22/M20 Q1023 NOSIG=
VILH 020700Z 18006KT 6000 FEW070 22/M19 Q1023 NOSIG=
VILH 020730Z 18008KT 6000 FEW070 23/M22 Q1022 NOSIG=
VILH 020800Z 16004KT 6000 FEW070 24/M21 Q1022 NOSIG=
VILH 020900Z 25004KT 6000 SCT070 24/M20 Q1020 TEMPO 29015G25KT=
VILH 021000Z 32004KT 6000 SCT070 25/M23 Q1019 NOSIG=
VILH 020930Z 09007KT 6000 SCT070 26/M22 Q1019 NOSIG=
VILH 021030Z 30004KT 6000 SCT070 25/M23 Q1019 NOSIG=
VILH 021100Z 11003KT 6000 SCT070 25/M20 Q1018 NOSIG=
VILH 021130Z 25008KT 6000 SCT070 25/M20 Q1018 NOSIG=
VILH 021200Z 29003KT 6000 SCT070 26/M23 Q1018 NOSIG=
VILH 021230Z 29007KT 6000 SCT070 24/M21 Q1018 NOSIG=
VILH 021300Z 30013KT 6000 SCT070 22/M20 Q1018 NOSIG=
VILH 021330Z 30019KT 6000 SCT070 21/M16 Q1018 NOSIG=
VILH 021400Z 30017KT 6000 SCT070 20/M15 Q1018 NOSIG=
VILH 021430Z 30015KT 6000 SCT070 20/M14 Q1019 NOSIG=
VILH 021500Z 29015KT 6000 SCT070 20/M14 Q1020 NOSIG=
VILH 021530Z 30015KT 6000 SCT070 19/M14 Q1021 NOSIG=
VILH 021630Z 32008KT 6000 SCT070 19/M14 Q1021 NOSIG=
VILH 021730Z 29006KT 6000 FEW070 SCT120 17/M11 Q1022 NOSIG=
Leh METARs of 03MAY2022
VILH 021800Z 29004KT 6000 FEW070 SCT120 17/M11 Q1022 NOSIG=
VILH 021930Z 31005KT 6000 SCT070 16/M10 Q1022 NOSIG=
VILH 022030Z 31004KT 6000 SCT070 16/M10 Q1022 NOSIG=
VILH 022100Z 32003KT 6000 SCT070 15/M10 Q1021 NOSIG=
VILH 022230Z VRB02KT 6000 SCT100 11/M08 Q1022 NOSIG=
VILH 022330Z VRB01KT 6000 FEW120 09/M08 Q1023 NOSIG=
VILH 030000Z VRB02KT 6000 FEW100 08/M06 Q1023 NOSIG=
VILH 030100Z VRB01KT 6000 FEW150 09/M09 Q1024 NOSIG=
VILH 030130Z VRB01KT 6000 FEW150 10/M06 Q1024 NOSIG=
VILH 030230Z VRB01KT 6000 FEW150 16/M08 Q1024 NOSIG=
VILH 030300Z VRB02KT 6000 FEW150 18/M07 Q1024 NOSIG=
VILH 030330Z 03003KT 6000 FEW150 18/M07 Q1024 NOSIG=
VILH 030332Z 03003KT 6000 FEW150 18/M07 Q1024 NOSIG RMK ALL APPROACHES CLEAR=
VILH 030500Z 12005KT 6000 FEW070 SCT150 21/M10 Q1023 NOSIG=
VILH 030530Z 10006KT 6000 FEW070 SCT150 23/M10 Q1023 NOSIG=
VILH 030600Z 09005KT 6000 FEW070 SCT150 24/M12 Q1022 NOSIG=
VILH 030630Z 05006KT 6000 SCT070 SCT150 23/M14 Q1021 NOSIG=
VILH 030700Z 16004KT 6000 CTHT SCT070 SCT150 23/M13 Q1020 NOSIG=
VILH 030800Z 29015G25KT 6000 CCHT BKN070 SCT150 23/M11 Q1019 TEMPO 29025KT 5000 BLDU=
VILH 030830Z 27010KT 6000 CCHT SCT060 FEW060TCU BKN150 24/M13 Q1019 TEMPO 30025G35KT 5000 BLDU=
VILH 030930Z 25015G25KT 6000 CCHT FEW060TCU SCT060 BKN150 20/M08 Q1018 NOSIG=
VILH 031030Z 30015G25KT 5000 BLDU FEW060TCU SCT060 BKN150 19/M04 Q1018 TEMPO 30034KT=
VILH 031140Z 30034KT 3000 BLDU SCT060 FEW060TCU BKN120 13/M03 Q1023 NOSIG=
VILH 031200Z 29022G37KT 2000 BLDUVCSH SCT050 FEW060TCU BKN120 12/M00 Q1024 TEMPO 30034KT=
VILH 031300Z 30012KT 5000 VCSHSOCCB LDU SCT050 FEW060TCU BKN120 11/M00 Q1026 TEMPO 30025KT=
VILH 031330Z 12009KT 6000 VCSHSOCC BKN050 FEW060TCU BKN120 11/00 Q1026 NOSIG=
VILH 031400Z 15006KT 6000 SCT050 BKN120 11/00 Q1026 NOSIG=
VILH 031500Z 16008KT 6000 SCT050 BKN120 10/M00 Q1027 TEMPO 32015G25KT=
VILH 031530Z 13006KT 6000 SCT050 BKN120 10/M00 Q1028 TEMPO 32015G25KT=
VILH 031630Z 12009KT 6000 SCT060 FEW060TCU BKN120 09/01 Q1028 TEMPO 32015G25KT=
VILH 031730Z 16006KT 6000 SCT060 FEW060TCU BKN120 09/00 Q1027 TEMPO 32015G25KT=
Leh METARs 05May2022
VILH 041800Z 29012G22KT 6000 FEW070 BKN120 14/M06 Q1021 NOSIG=
VILH 041930Z 30017KT 6000 FEW070 BKN120 13/M05 Q1021 TEMPO 29025KT=
VILH 042030Z 29013KT 6000 FEW070 BKN120 12/M05 Q1021 TEMPO 29025KT=
VILH 042130Z 30012KT 6000 FEW070 BKN120 12/M04 Q1021 NOSIG=
VILH 042230Z 29014KT 6000 FEW070 BKN120 11/M04 Q1022 NOSIG=
VILH 042330Z 29008KT 6000 SCT070 BKN100 11/M04 Q1022 NOSIG=
VILH 050030Z 29009KT 6000 SOCC SCT060 BKN100 11/M04 Q1023 TEMPO 29015KT=
VILH 050101Z 29009KT 6000 VCSH SCT060 BKN100 11/M04 Q1023 TEMPO 29015KT RMKS PASSES W CLEAR E P/CLEA
VILH 050100Z 30010KT 6000 VCSH SCT060 BKN100 11/M04 Q1023 TEMPO 29015KT=
VILH 050200Z 28010G20KT 6000 VCSH SCT060 BKN120 12/M04 Q1024 TEMPO 29015KT=
VILH 050201Z 28010G20KT 6000 VCSH SCT060 BKN120 12/M04 Q1024 TEMPO 29015KT RMKS PASSES W CLEAR E P/C
VILH 050230Z 29010KT 6000 VCSHSOCC SCT060 BKN120 12/M04 Q1024 TEMPO 29015KT=
VILH 050330Z 29011KT 6000 VCSHSOCC SCT060 BKN120 15/M05 Q1024 TEMPO 29015KT=
VILH 050335Z 29011KT 6000 VCSH SCT060 BKN120 14/M04 Q1024 TEMPO 29015KT RMK WISHKEY CLEAR ECHO PARTI
VILH 050435Z 24004KT 6000 SOCC SCT060 BKN120 15/M06 Q1023 RMK WHISKEY CLEAR KLO PARTIALLY CLEAR REST
VILH 050500Z VRB02KT 6000 SOCC SCT060 BKN120 17/M07 Q1023 NOSIG=
VILH 050630Z 14007KT 6000 SOCC SCT060 SCT120 19/M08 Q1021 NOSIG =
VILH 050730Z 17009KT 6000 SCT070 SCT120 21/M11 Q1020 TEMPO 29015G25KT=
VILH 050800Z 14007KT 6000 CTHT SCT060 SCT120 21/M12 Q1019 TEMPO 29015G25KT=
VILH 050830Z 30008KT 6000 CTHT FEW060 SCT070 21/M13 Q1019 NOSIG=
VILH 050930Z 32013G23KT 6000 CTHT FEW060 SCT070 20/M13 Q1018 TEMPO 27015G25=
VILH 051000Z 29007G20KT 6000 SOCC FEW060TCU SCT070 SCT120 22/M13 Q1017 TEMPO 29015G25KT=
VILH 051030Z 30015G25KT 6000 VCSHSOCC FEW060TCU SCT070 SCT120 21/M13 Q1017 TEMPO 29025 =
VILH 051100Z 29013G23KT 6000 SOCC SCT070 FEW070TCU SCT120 21/M12 Q1017 TEMPO 29025=
VILH 051130Z 30018G29KT 6000 SOCC SCT070 FEW070TCU SCT120 20/M12 Q1017 TEMPO 29025=
VILH 051200Z 29021G31KT 6000 SOCC SCT070 FEW070TCU SCT120 20/M13 Q1017 29025KT=
VILH 051230Z 30018G28KT 5000 BLDUSOCC SCT070 FEW070TCU SCT120 19/M12 Q1017 TEMPO 29025KT=
VILH 051300Z 30015G25KT 5000 BLDUSOCC SCT070 FEW070TCU SCT120 18/M12 Q1018 TEMPO 30025KT=
VILH 051330Z 30015G25KT 6000 SOCC SCT070 17/M10 Q1018 TEMPO 29025KT=
VILH 051400Z 30014G24KT 6000 SCT070 17/M11 Q1018 TEMPO 30025KT=
VILH 051430Z 30010KT 6000 SCT070 17/M10 Q1019 NOSIG=
VILH 051500Z 29010KT 6000 SCT070 16/M10 Q1019 NOSIG=
VILH 051530Z 29014G26KT 6000 SCT070 16/M09 Q1020 NOSIG=
VILH 051630Z 30017G27KT 6000 SCT070 15/M08 Q1021 NOSIG=
VILH 051730Z 30012G22KT 6000 SCT070 14/M08 Q1021 NOSIG=
Leh METARs of 17APR2022
VILH 161800Z 23004KT 6000 FEW060 SCT100 07/M07 Q1024 NOSIG=
VILH 161930Z VRB01KT 6000 FEW060 SCT100 05/M08 Q1025 NOSIG=
VILH 162030Z VRB01KT 6000 FEW060 SCT100 04/M08 Q1025 NOSIG=
VILH 162100Z VRB01KT 6000 FEW060 SCT100 03/M08 Q1026 NOSIG=
VILH 162130Z VRB01KT 6000 FEW060 SCT100 03/M08 Q1026 NOSIG=
VILH 162230Z VRB01KT 6000 FEW060 SCT100 02/M08 Q1026 NOSIG=
VILH 162330Z VRB01KT 6000 FEW060 SCT100 01/M08 Q1027 NOSIG=
VILH 170130Z VRB01KT 6000 FEW070 02/M08 Q1028 NOSIG=
VILH 170135Z VRB01KT 6000 FEW070 03/M08 Q1028 NOSIG RMKS ALL APPROACHES CLEAR=
VILH 170200Z VRB01KT 6000 FEW070 04/M07 Q1029 NOSIG=
VILH 170230Z VRB01KT 6000 FEW070 06/M07 Q1029 NOSIG=
VILH 170300Z VRB02KT 6000 FEW070 10/M07 Q1029 NOSIG=
VILH 170330Z VRB02KT 6000 FEW070 12/M08 Q1029 NOSIG=
VILH 170500Z 34005KT 6000 FEW070 13/M13 Q1028 NOSIG RMK ALL APPROACHES CLEAR=
VILH 170501Z 34005KT 6000 FEW070 13/M13 Q1028 NOSIG RMK ALL APPROACHES CLEAR=
VILH 170600Z 11006KT 6000 SCT070 16/M15 Q1028 NOSIG=
VILH 170700Z 02006KT 6000 SCT070 17/M18 Q1027 NOSIG=
VILH 170730Z 11005KT 6000 SCT070 17/M17 Q1026 NOSIG=
VILH 170800Z 15005KT 6000 CTHT SCT070 17/M19 Q1026 NOSIG=
VILH 170830Z 08006KT 6000 SCT070 19/M20 Q1025 NOSIG=
VILH 170900Z 14006KT 6000 FEW070 20/M18 Q1024 NOSIG=
VILH 170930Z VRB02KT 6000 FEW070 20/M19 Q1024 NOSIG=
VILH 171000Z 24005KT 6000 FEW070 19/M21 Q1023 NOSIG=
VILH 171030Z 29005KT 6000 FEW070 18/M22 Q1023 NOSIG=
VILH 171100Z 23005KT 6000 FEW070 18/M22 Q1023 NOSIG=
VILH 171130Z 34003KT 6000 FEW070 19/M21 Q1023 NOSIG=
VILH 171200Z 29004KT 6000 FEW070 18/M22 Q1022 NOSIG=
VILH 171230Z 16005KT 6000 FEW070 17/M23 Q1022 NOSIG=
VILH 171300Z 21003KT 6000 FEW070 SCT150 17/M21 Q1022 NOSIG=
VILH 171330Z 23003KT 6000 FEW070 SCT150 15/M17 Q1023 NOSIG=
VILH 171400Z 24003KT 6000 FEW070 SCT150 15/M16 Q1023 NOSIG=
VILH 171500Z VRB02KT 6000 FEW070 SCT150 14/M16 Q1024 NOSIG=
VILH 171530Z VRB02KT 6000 FEW070 SCT150 13/M16 Q1025 NOSIG=
VILH 171630Z 30005KT 6000 FEW070 SCT150 13/M17 Q1025 NOSIG=
VILH 171730Z 30005KT 6000 FEW070 SCT150 13/M16 Q1026 NOSIG=
Leh METARs 22APR2022
VILH 211800Z 32005KT 6000 SCT060 BKN120 08/M08 Q1024 NOSIG=
VILH 211930Z 17006KT 6000 -RA FEW040 SCT060 BKN100 07/M03 Q1025 NOSIG=
VILH 212030Z 36005KT 6000 FEW040 SCT060 BKN100 06/M01 Q1025 TEMPO -RA=
VILH 212100Z 14003KT 6000 -RA SCT040 SCT060 BKN100 05/M00 Q1025 NOSIG=
VILH 212130Z VRB01KT 6000 -RA SCT040 SCT060 BKN100 04/01 Q1025 NOSIG=
VILH 212230Z VRB02KT 6000 -RA SCT040 SCT060 BKN100 04/03 Q1025 NOSIG=
VILH 212330Z VRB01KT 6000 FEW030 SCT070 BKN150 03/03 Q1025 NOSIG=
VILH 220000Z VRB01KT 6000 SOCC SCT020 SCT070 BKN100 03/03 Q1025 TEMPO BKN015=
VILH 220030Z VRB02KT 6000 SOCC SCT015 SCT050 BKN100 03/03 Q1026 TEMPO BKN015=
VILH 220100Z VRB02KT 6000 -RASOCC SCT015 BKN100 03/03 Q1026 TEMPO BKN015=
VILH 220101Z VRB02KT 6000 -RA/SOCC SCT015 BKN100 03/03 Q1026 NOSIG RMKS PASSES NOT CLEAR=
VILH 220130Z VRB01KT 6000 SOCC FEW012 SCT015 BKN100 04/03 Q1026 TEMPO -RA=
VILH 220200Z VRB02KT 6000 SOCC FEW012 SCT015 BKN100 05/03 Q1027 TEMPO -RA=
VILH 220230Z 11003KT 6000 SOCC FEW012 SCT015 BKN100 05/02 Q1027 TEMPO -RA=
VILH 220300Z 11007KT 6000 -RASOCC SCT012 SCT015 BKN090 05/01 Q1027 NOSIG=
VILH 220330Z 13008KT 6000 SOCC SCT012 SCT015 BKN090 05/01 Q1028 TEMPO -A=
VILH 220400Z 12006KT 6000 SOCC SCT015 SCT030 05/01 Q1028 NOSIG=
VILH 220430Z 11005KT 6000 SOCC SCT050 SCT120 07/01 Q1028 NOSIG=
VILH 220500Z 13003KT 6000 SOCC SCT050 SCT120 11/M02 Q1027 NOSIG=
VILH 220530Z VRB02KT 6000 SOCC SCT050 SCT070 BKN120 12/M02 Q1026 NOSIG=
VILH 220600Z 29008KT 6000 SOCC FEW050 SCT070 BKN120 10/M03 Q1026 TEMPO -RA=
VILH 220630Z 28004KT 6000 SOCC SCT050 SCT120 11/M04 Q1025 N0SIG=
VILH 220700Z VRB02KT 6000 SOCC SCT060 SCT120 14/M05 Q1025 NOSIG=
VILH 220730Z 20004KT 6000 SOCC SCT060 SCT120 14/M06 Q1024 NOSIG=
VILH 220800Z VRB02KT 6000 SOCC SCT060 BKN120 16/M07 Q1023 NOSIG=
VILH 220830Z 19005KT 6000 SOCC SCT060 BKN120 15/M08 Q1023 NOSIG=
VILH 220930Z 29006KT 6000 SOCC FEW050TCU SCT060 BKN120 14/M08 Q1021 NOSIG=
VILH 221000Z 25005KT 6000 SOCC FEW050TCU SCT060 SCT120 15/M08 Q1020 TEMPO 29015G25KT=
VILH 221030Z 27004KT 6000 SOCC SCT060 SCT120 15/M08 Q1020 TEMPO 29015G25KT=
VILH 221100Z 26005KT 6000 SOCC SCT060 SCT120 15/M09 Q1020 NOSIG=
VILH 221130Z 18003KT 6000 SOCC SCT060 SCT120 14/M09 Q1019 NOSIG=
VILH 221200Z 27005KT 6000 SOCC SCT060 SCT120 14/M09 Q1019 NOSIG=
VILH 221230Z 23004KT 6000 SOCC SCT060 SCT060 15/M10 Q1020 NOSIG=
VILH 221300Z 30011G21KT 6000 SOCC SCT060 SCT120 14/M11 Q1020 TEMPO 30015G25KT=
VILH 221430Z 28010G20KT 6000 FEW060TCU SCT060 SCT120 11/M09 Q1021 TEMPO 29015G25KT=
VILH 221730Z 29008KT 6000 SCT060 SCT120 10/M08 Q1024 NOSIG=
