 |
 This
unusual sequence of charts, 6-hourly from 10pm on Thursday
to 4pm Sunday, shows the development of the secondary low off
the East Gippsland Coast late Friday morning. The low became
nearly stationary for 48 hours before moving away to the east
on Sunday afternoon. A band of moisture and instability circled
around the southern side of the low, giving the most intense
rain to the Sale/Bairnsdale area. The animation pauses at 4am
today when rain was at its most intense. But this is an unusual
chart in other respects for it features two secondary
lows, the other to the west of Perth, both at nearly an identical
phase in their development. Unusually for an Australian weather
chart,
both
lows are depicted with a
warm sector, marked by the warm fronts advancing on Tasmania
in the east and to the SW of Perth in the west. In both cases,
the frontal zone extends SE to the parent low, the one from
the East Gippsland low marked as stationary. Both secondaries
occluded over the next 24 hours as the cool and warm air masses
mixed, though the Bureau analyst has held back from showing
occluded fronts,
being content
with showing weakening cold fronts. BoM  |
 |
 Rainfall
for the week ended 9am Sunday 25 April. All of the rain shown
for VIC fell during the frontal/secondary passage over the
3 days to Sunday. BoM |
 |
 Rain
gaugings for the 24 hours to 9am today. The heaviest totals are
where the moist air returning around the Low hit the coast
and extended into the adjacent Latrobe Valley west of Sale. BoM |
 Best
rain in 6 years brings flooding to Gippsland VIC
The heaviest general rain since 1998 fell in Gippsland overnight
and today. Local flooding occurred, but dry catchments meant
that main river flooding was minor and brief. Several locations set
new April daily rainfall records as 100 to 200mm was recorded at
a number of places in East and West Gippsland.
The colour-coded rainfall registrations in  for
the 24 hours to 9 this morning show an unusually even gradation across
VIC. This reflects the synoptic situation  in
which the rainband associated with a developing secondary low slowed
down as it moved east, finally grinding to a halt to the SE of Sale
and Bairnsdale overnight. Bairnsdale Airport received 75 of its record
103.2mm 24 hour total between midnight and 9am. In the same 9 hours,
Mt Moornapa,
40km north of Sale, received 90mm. Dozens of locations, from Warburton
east to Bairnsdale and north to Mt Buller, recorded over 50mm at
the 9am daily reading, with the highest 154mm at Lindenow, 12km
WNW of Bairnsdale.
A very long-standing rainfall record was broken at Omeo, where the
24 hour total of 51.8mm was the highest April daily fall in 125 years.
East Sale RAAF's 105.8 was its highest April total in 61 years.
Rain continued around Sale and Bairnsdale and in the mountains to
the north during the day but eased late afternoon. Highest official
totals for the week to 9am Sunday  ,
all of which fell during the last 72 hours, were:
198.2 MT BAW BAW
166.4 BULLUMWAAL
159.6 MT MOORNAPA
154 LINDENOW
150.8 BAIRNSDALE (MITCHELL RIVER @ ROSEHILL)
137 BAIRNSDALE AIRPORT
125 EAST SALE COMPARISON
123.6 EAST SALE AIRPORT
110 REEVES KNOB
102.4 MOUNT TAMBORITHA
Minor flooding occurred in the lower Mitchell, with the river at
Bairnsdale peaking at 4.8m this evening, 0.8m above minor level.
The Tanjil River was above minor level at Tanjil Junction, north
of Moe, from around midday today to early Sunday morning, but the
low level of Blue Rock Dam prevented flooding around Tanjil South.
Elsewhere, peaks were below minor flood level. Floodwaters across
the main Princes Highway between Bairnsdale and Sale hampered but
did not stop traffic.
Snow falls in VIC, NE TAS
Cold air coupled with the precipitation gave heavy snow
in the VIC Alps. ABC Radio reported 30cm of snow at Mt
Hotham, 25cm at nearby Dinner Plain and "similar amounts"
at Mt Buller. Moist but cold air swinging around the southern side
of the low gave snow to the NE TAS Highlands. A Ben Lomond hotel
proprietory told ABC Radio that 5cm of snow had fallen overnight.
Strong winds accompanied the rain in TAS during the morning, with
Eddystone Point reporting a top gust of 109km/h at 4am and Devonport
Airport reporting a gust of 87km/h shortly before 10am.
Heavy rain on North QLD Coast
Moderate to heavy rain fell on the QLD North Coast from
Cairns to south of Townsville from late this morning to early Sunday
morning. Raingauges in the Tully and Innisfail areas recorded
the highest totals of 100 to over 200mm in the 24 hours to 9am Sunday,
with the heaviest rain falling between noon and midnight today.
Bulgun Creek flood alert gauge in the Tully River catchment recorded
206mm in the 24 hours to 9am Sunday, of which 155 fell between noon
and midnight. Other heavy 24 hour totals to 9am Sunday were Daradgee
6km NW of Innisfail 163.4mm, Tully town 140.0 and Innisfail 122.4.
Farther south, Ingham recorded 68 and Townsville 38. The rain developed
as a moist onshore flow interacted with instability produced by
a tongue of upper cold air extending up the QLD coast. In situations
such as these, the uplift provided by mountains that rise to over
1,500m immediately behind the coast from Cairns south to Cardwell
are an even greater factor in producing the rain than the general
meteorological situation. Mt Bartle Frere, Queensland's highest
peak, rises to 1,611m 25km NW of Innisfail. |
