Synoptic Situation: A high over the Tasman Sea extends a weakening ridge along the east coast of Queensland.
Forecast: Isolated morning fogs about the Tablelands and southern coast, clearing to a fine though a partly cloudy day. Light to moderate SE to NE winds.
Cloud Forecasts
BoM Access Model: Clear skies. Some low cloud only clearing inland late in the night and some low cloud offshore later in the morning.
Skippy Sky: Clear skies, except for indicated 20-30% high cloud, up to 50% on both north and south sides of eclipse track.
EU: Clear skies in Cairns with just a small amount (5-20%) low cloud indicated for Port Douglas. Clear skies inland.
Observed Weather
Cairns: Clear skies except for some thin/isolated fog patches visible on webcam (unlikely to have caused an issue).
Elsewhere: Clear skies in the southern half of eclipse track, but a band of cloud extending across Cape York in the northern half with heavier cover further west. Only thin/isolated clouds towards eastern end (60km in from coast).
The narrow band of cloud across Cape York was below the resolution/ability of most models (but the BoM model picked it quite well, it just took an extra couple of hours to clear). Despite that, all the models were broadly correct.
Chance of Success (if eclipse had been this day)
Coast: >90%
60km Inland: >70%
Synoptic Situation: A high is moving eastwards across southeastern Australia and will enter the Tasman Sea late this evening. A surface trough extends through the interior of the state and is expected to move into western Queensland during Monday.
Forecast: Isolated light morning showers about the coast and ranges. Otherwise fine, partly cloudy until isolated mid afternoon showers and thunderstorms develop over the western Tablelands.
Cloud Forecasts
BoM Access Model: Generally clear but a little low cloud indicated around the ranges and offshore, more so after eclipse time.
Skippy Sky: Some low cloud around the ranges and offshore, especially south of Cairns. A little high cloud in a band above the northern edge of eclipse track.
EU: Variable estimates of low cloud (10-90%) for Cairns and Port Douglas. Similar for 60km inland locations, although Mount Mulligan shows as clear. Mount Carbine shows a little precipitation as well.
Observed Weather
Cairns: Low and mid level clouds but a lucky clear gap around eclipse time in the morning.
Elsewhere: Large patch of low cloud around Port Douglas extending 30km inland and further offshore. Generally clear across the rest of the eclipse track.
The models again not doing too bad on the broad picture, but a bit sketchy on the low cloud details. US model again over stating high cloud.
The forecasts indicated a retreat inland as the best option and this turned out to be the case.
Chance of Success (if eclipse had been this day)
Coast: ~40%
60km Inland: ~80-90%
Synoptic Situation: A high over the Tasman Sea extends a ridge along Queensland's east coast.
Forecast: Isolated light showers about the coast and ranges during the morning. Isolated showers and thunderstorms over the Tablelands during the afternoon.
Cloud Forecasts
BoM Access Model: Some low cloud indicated off the coast and perhaps a small amount along the ranges.
Skippy Sky: Patches of low cloud indicated around Mt Carbine and offshore Port Douglas. Up to 50% high cloud indicated around Cairns, north of the eclipse track and to a lesser extent inland.
EU: 30-70% low cloud in coastal areas. Generally clear skies 60km inland.
Observed Weather
Cairns: Few low clouds.
Elsewhere: A few low clouds offshore and on the ranges behind Port Douglas and south of Cairns but plenty of gaps as well. Generally clear skies inland across the rest of the eclipse path.
I give the models another nod for today, all broadly indicating the common pattern of some cloud around the coast (although underestimating its extent offshore) with clear skies inland. US model again overstating high cloud.
Chance of Success (if eclipse had been this day)
Coast: ~50% (maybe higher)
60km Inland: ~90%
So if it is clear inland will coastal cloud be likely to block the eclipse at only 12 degrees elevation? I am going to be about 75km inland. These analysis of predicted and actual likely of seeing eclipse from day to day don't clarify this issue for me.
looking at todays timelapse http://www.gorgecreekorchards.com.au/solar_eclipse.html
Mareeba: would just see Total then the light clouds roll in from the S
Cairns: some clouds at sunrise but total would of been ok
Mt Carbine: clear from sunrise to the end
So if it is clear inland will coastal cloud be likely to block the eclipse at only 12 degrees elevation? I am going to be about 75km inland. These analysis of predicted and actual likely of seeing eclipse from day to day don't clarify this issue for me.
Mark
If there is only low cloud along the coast or over the ranges then from 75km inland it will be fine. eg.. if the cloud height is 2000m, then with the sun angle of 13 degrees, you'd need to be more than 8km further west for the sun to clear the cloud.
if there are cumulus clouds reaching say 5000m (could easily be higher some days, but not so often in the morning) then you need to be 20km west of them. still generally ok if the clouds are only along the coast/ranges.
often though there is cloud much further inland as well. If you look at the high resolution visible satellite images that houghy has posted, you can actually see the shadow of the cloud on the ground.. as long as you're not in that shadow you're fine.
but we won't have high res satellite images to use during the night before the eclipse.. only low res infrared images.
Synoptic Situation: A high over the central Tasman Sea extends a weakening ridge along Queensland's east coast.
North Tropical Coast and Tablelands Forecast: Mainly fine, Isolated morning coastal shower or two. Light to moderate E to SE winds.
Cairns Forecast: Fine, mostly sunny.
Cloud Forecasts
BoM Access Model: Generally clear. A little low cloud offshore (close to the coast) and possibly a little over the ranges (hard to discern), more so south of the eclipse area.
Skippy Sky: Low cloud offshore and again indicated around Mt Carbine. Heavy high cloud shown lined up across the inland eclipse path.
EU: 30-60% low cloud along the coast. 0-30% low cloud 60km inland, a little more at Mt Carbine closer to the ranges.
Similar patterns to previous days and similar predictions from the models, which have done well on the broad picture and even some of the details. US model again predicted a band of high cloud that was not present.
On another note about the the US Model (via Skippy Sky).. it clearly has a model grid point near Mt Carbine. There is often a point of low cloud in the models shown here, but the resolution of the model is not sufficient to show the real pattern of how this may extend to other areas of the ranges.
It's clearly an artifact that this one high elevation point in the model generates a diamond shaped spike for low cloud, and interpolates to zero at the surrounding grid points. I don't think it should be interpreted as meaning the model can tell something special about this location as compared to others along the ranges.
Observed Weather
Cairns: Luckily clear at eclipse time.
Elsewhere: Clouds just offshore and over the ranges behind Port Douglas would have blocked the view for many on the coast. Generally clear across the inland path, although a large area of cloud just south of the track.
Chance of Success (if eclipse had been this day)
Coast: ~50% (very hard to estimate)
60km Inland: ~90%
I just checked Cairns forecast 30/10. Morning showers Tues and Wed, fine Thurs and Fri.
Greg.
are you talking about the long-term forecast for Cairns for the eclipse week? ok for a laugh but i wouldn't place any meaning on a two week forecast anywhere, but especially in FNQ! even three day forecasts are bouncing around a lot. just cross your fingers and hope for the best!
Thanks Phil, great explanation. So it looks like inland cloud will be the thing to spoil the party. On the whole it looks like the coastal fringe is more often in cloud than inland so I am probably in the best place but its still clearly very much a game of chance.
Quote:
Originally Posted by philiphart
Mark
If there is only low cloud along the coast or over the ranges then from 75km inland it will be fine. eg.. if the cloud height is 2000m, then with the sun angle of 13 degrees, you'd need to be more than 8km further west for the sun to clear the cloud.
if there are cumulus clouds reaching say 5000m (could easily be higher some days, but not so often in the morning) then you need to be 20km west of them. still generally ok if the clouds are only along the coast/ranges.
often though there is cloud much further inland as well. If you look at the high resolution visible satellite images that houghy has posted, you can actually see the shadow of the cloud on the ground.. as long as you're not in that shadow you're fine.
but we won't have high res satellite images to use during the night before the eclipse.. only low res infrared images.
how forecasts can change in a few hours
