Mission Plan:
Primary Mission : Hobart Operations Completed Alternate Mission: None Future Mission(s): C-130 Departs Saturday morning for USAAircraft Operations
Take-off Time: N/A) Pre-flight Weather Briefing Time: N/A Updates: N/A Airborne Mission Scientist: N/A Mission Scientist: N/AShip Operations
Discoverer: Discoverer will continue atmospheric and seawater sampling in the vicinity of 45S, 145E until 1700 LDT today (0600 UTC, 12 Dec) when Discoverer departs for Hobart. They will arrive in Hobart Wednesday morning. A regular 4/day sounding schedule will be maintained with the possibility of extra soundings during the intercomparison with the aircraft. See catalog reference below for detailed instrument status. Discoverer Lead Scientist: Tim Bates Southern Surveyor: Southern Surveyor has completed its cruise and is in port in Hobart. Southern Surveyor Lead Scientist: Bronte Tilbrook
48 hour MSL P Prognosis is here
72 hour MSL P Prognosis is here
Latest Visible Sat Picture is here
Surface Wind 24-h forecast is here
GASP trajectory analysis is here
Synoptic Situaton at 00Z Tuesday 12/12/95:
A warm front lies near a line 45S 143E/50S 149E moving E at 20/25 knots, forecast to be near Hobart/50S 152E at 12Z tonight.
A cold front near 48S 130E/49S 140E/55S 153E moving ENE at 40 knots and weakening north of 50S. Another front is forecast to form between 50S 130E and a low below 960 hPa near 60S 132E at 12z tonight. Front to move northeastwards to be near Tasmania/50S 150E/960 hPa low near 62S 140E at 00Z. Front to cross Macquarie tomorrow night.
1026 hPa high near 37S 123E moving east at 20 knots extends a large ridge towards southern Australia.
Strong northwest to southwest airstream south of the ridge across most of the ACE area.
Prognoses:
0-24 hours: The front to cross Tasmania tomorrow (hell bent on giving the Discoverer a parting kick up the stern) is still in the process of developing and so is hard to time. However, there does appear to be good upper support for the front's development and it may well form from the remnants of the front which is currently passing south of Tasmania, which is successfully stuffing up the last SC experiment near the Disco. The associated deep low to the far south is being picked up by all the progs and this should maintain the strong NW/SW stream across the ACE area.
24-72 hours: The deep low near 60S is forecast to track only slowly eastwards and weaken during the next few days, such that it crosses Macquarie in a somewhat weakened form on Saturday. The ridge over the Bight is expected to weaken on Thursday as the remnants of TC Frank move southeastwards through Western Australia. Should the low make it as far south as the Bight, a very complicated pattern is likely to evolve towards the end of the week in the Tasmanian latitudes.
FORECASTS FOR TONIGHT AND WEDNESDAY 13/12/95:
Cape Grim:
Weather: A few light showers or drizzle patches, increasing tomorrow afternoon. Wind: Chiefly west to northwest 15/25 knots tending southwesterly tomorrow afternoon and possibly reaching 30 knots at times just following the change.
Macquarie Island:
Weather: A period of rain this evening then some further showers tomorrow, increasing tomorrow night. Winds: Northwest 25/35 knots easing to 20/30 knots following the front this evening but increasing to 25/35 knots again tomorrow.
R/V Discoverer:
Weather: A few light showers or drizzle patches. Wind: Chiefly west to northwest 20/30 knots. Seas to 3 metres. 2.5 to 3.5 metre west to southwest swell.
No Disco observations have got into the system for 48 hours.
REVIEW OF PREVIOUS DAY's FORECASTS: The warm front near Tasmania produced more middle level cloud than was anticipated, resulting in the SC being covered by layers of altostratus and occasionally, cirrus. This has made today's experiment over and under the SC somewhat difficult. However, forecasts in the other locations have been quite good. Hail was reported yesterday by both Cape Grim and the Discoverer and was predicted for Monday in Sunday's forecast. Winds on Macquarie have strengthened slightly quicker than was forecast, but otherwise, wind forecasts for all three platforms was accurate.
This is possibly the last forecast to be issued and if it is, we in the forecasting centre (Neil Adams and I) would like to thank you for all your observations during the project. We hope you have found the forecasts accurate and timely. We also trust you have a very merry Christmas and a happy new birthday.
Alasdair Hainsworth. Project Forecaster.
