 |
| The weather chart for 2pm WST shows a double-centred
low in a trough lying from offshore Perth to the Kimberley and moving slowly
southeast. Very warm, dry and sunny conditions prevailed
north of the trough while cold, windy weather occurred to the south. Modest
levels of moisture, which have been feeding down from northern Australia
over the past few days, interacted with cold upper air to produce strong
instability and middle atmosphere uplift along and to the south of the
trough where thunderstorms, some severe, dumped up to 80mm of rain. |
 Torrential
thunderstorm rainfall fell across much of southern WA today in an
unusual weather setup that also saw huge temperature extremes. The chart
and explanation at right sets the scene.
The trough that triggered heavy showers and widespread thunderstorms brought
falls of up to 30mm around Perth in a few hours before 9am -- coastal Swanbourne
in Perth's western suburbs recorded 27mm between 6 and 9am. Thunderstorms were
sporadic but widely spread throughout the day south of and along the troughline
with the heaviest falls generally progressing eastward, steered by the upper-level
flow.
Very heavy rain fell at, and to the north and east of Albany between
about 9am and 9pm. In the 24 hours to 9am Tuesday, White Gums, 50km north
of the city, recorded 81.4mm, Mettler, 75km NE, 77.8, and Bremmer Bay, 150km
ENE,
69.4. Albany itself received 66.2 at the airport. Other high falls are given here.
Mount Barker, Mettler, Albany Airport and Norseman set significant new September
one-day rainfall records -- Mount
Barker and Norseman's were the heaviest in nearly 100 years of record, while
Mettler's was more than twice the previous record. Details are here. While the falls were welcomed by farmers expecting a bumper crop, shire engineers
were less happy. In Plantagenet Shire, a number of roads were closed by up
to two metres of water that cut through graded roads along creek lines.
Maximum temperatures to 3pm reflected the strong temperature differences across
the trough. In the south, maxima struggled to reach mid-teens, with Mount Barker
reaching only 11, Katanning and Ongerup 12 and Eucla 13 (8 below normal). To
the north, Eneabba recorded 30 and Carnegie 37, 7 or 8 above normal.
 Snow
fell to low levels in TAS both overnight and through the day, giving
some of the best snow depths reported from Bureau stations so far this season.
At 9am, Lake St Clair reported 14cm of level snow, Tarraleah Village 10 and
Cradle Mountain Airfield 3. Maydena, 275m above sea level, reported snow
falling but not settling before 9am and during the day. Snow was also reported
falling at Palmers Lookout (191m asl) behind Port Arthur, Lake Leake
(580m) in the northeast, and patchy snow was on the ground at Strathgordon
(322m) at 9am. South coastal observers reported the snowline down to 2,000
feet and hail through the day. The temperature at the automatic weather station
atop Mt Read (1120m) behind Zeehan didn't
get
above
-0.7
all day.
In
VIC, Omeo (685m)
reported snow falling around dawn, and Melbourne's central city weather
station reported hail at midday with a temperature of 10C. In NSW, Bombala
PO (705m) reported sleet at 9am.
Scores
of fires continue to burn in NE NSW, with patrol, containment and
backburning work continuing in favourable weather conditions. Today's fire
count from the RFS is Tenterfield area 10, Severn 2, Kempsey 3, Nambucca
1, Hastings 11, Great Lakes 2, Gloucester 1.
Sources: NSW RFS, Albany & Great Southern Weekender |
