Experimental Melbourne Long Range Weather Forecast

(and Experimental Three-Month Victorian Seasonal Outlook
and Experimental Port Phillip Bay Forecast
and Experimental Terminal Aerodrome Forecast)

Based Upon Statistical Interpretation of NOAA Data

Combined With Human Forecasts

(http://www.arl.noaa.gov/ready.html)

NOAA Data At: 4pm, 10-3-2010

Minimum temperatures are for the night/early morning,
maximum temperatures are for the daytime,
whilst precipitation amounts and probabilities
are for the 24 hours from midnight.

Day & Date	Morning	Afternoon	Min Temp (deg C)	Max Temp (deg C)	Precip Amount (mm)	Precip Prob (%)	9am Wind/ 3pm Wind Melb Apt (km/hr)
Fri-12-3-2010	Fog.	Haze.	12	24	0	2	NW 5 SSE 10 Gusts30
Sat-13-3-2010	Sunny.	Sunny.	13	26	0	2	N 15 NNE 15 Gusts45
Sun-14-3-2010	Sunny.	Partly Cloudy.	14	27	0	7	N 15 NNE 15 Gusts45
Mon-15-3-2010	Sunny.	Partly Cloudy.	15	28	0	9	N 25 N 25 Gusts55
Tue-16-3-2010	Sunny.	Partly Cloudy.	15	28	0	10	N 15 NNE 15 Gusts45
Wed-17-3-2010	Sunny.	Partly Cloudy.	16	28	0	18	N 25 N 25 Gusts55
Thu-18-3-2010	Partly Cloudy.	Cloudy.	15	24	0	29	SSW 12 S 20 Gusts40
Fri-19-3-2010	Mist.	Sunny.	14	24	0	28	WSW 5 S 10 Gusts25
Sat-20-3-2010	Possible Shower.	Possible Shower.	14	25	0	44	N 30 N 25 Gusts60
Sun-21-3-2010	Possible Shower.	Possible Shower.	13	23	0	42	WNW 15 WSW 15 Gusts40
Mon-22-3-2010	Windy.	Windy.	14	23	0	46	N 40 NNW 40 Gusts80
Tue-23-3-2010	Possible Shower.	Possible Shower.	13	22	0	41	WNW 20 W 25 Gusts55
Wed-24-3-2010	Cloudy.	Sunny.	13	23	0	23	NNW 8 S 8 Gusts30
Thu-25-3-2010	Partly Cloudy.	Partly Cloudy.	14	24	0	25	N 10 NE 12 Gusts35

The Weather Icons

Acknowledgement: Bureau of Meteorology & World Meteorological Organisation

Sunny

Dry

Haze

Mist

Fog

Partly Cloudy

Cloudy

Windy

Dust

Possible Shower

Drizzle

Shower

Snow

Rain

Thunder

Cyclone

Definitions

Icon	Meaning
Sunny:	Sun shines >75% of the time
Dry:	As 'sunny', but used on days when Max > 30 Deg C & Relative Humidity drops below 10%
Haze:	As 'sunny', but used on days when visibility drops below 5000 m due to smoke
Mist:	Visibility below 5000 m due to water droplets but above 400 m (also used on days when isolated fog patches)
Fog:	Visibility below 400 m
Partly Cloudy:	Sun shines between 25% & 75% of the time
Cloudy:	Sun shines <25% of the time
Windy:	No precipitation & wind speed averages 'fresh' (18 kts) or stronger
Dust:	Visibility <1km due to dust raised by wind
Possible Shower:	Isolated light precipitation <25% of the metropolitan area
Drizzle:	Liquid precipitation that is almost continuous & made up of fine droplets
Shower:	Brief periods of liquid precipitation
Snow:	Snow or sleet falls (includes cases of flurries and/or ice)
Rain:	Liquid precipitation that is almost continuous but droplets are of medium size or large (not fine)
Thunder:	Thunder heard or lightning seen
Cyclone:	Wind speed averages 'storm force' (60 kts) or stronger

Weather Pattern for Fri-12-3-2010:
High southeast of Tasmania.
Moderate easterly flow across Victoria.

Bay Forecast

E to NE wind grading 5 to 15 knots southwards.
Waves similarly grading 0.5 to 1 metre southwards.

Click image below for
Andrew Watkins Bay Winds

Melbourne Terminal Aerodrome Forecast (TAF)

TAF YMML 1212 27010KT 9999 FEW035
FM21 21012KT 9999 SCT025
FM03 18012KT 9999 FEW035

RMK
T 16 13 11 12 Q 1036 1035 1033 1034

THREE MONTH OUTLOOK FOR APR/MAY/JUN:

NCEP's Depiction of the Global Sea Surface Temperature Evolution

Matt Wheeler's 10-Day Forecast of the Madden Julian Oscillation's Evolution

The average Indian Ocean Dipole Mode Index for the past week is -0.05, the average Southern Oscillation Index (SOI) for the past 90 days is -13.14, the average SOI for the past 30 days is -9.31, the latest recorded bimonthly Multivariate ENSO Index (MEI) is 1.502, and the expected MEI, adjusted by the Indian Ocean Dipole Mode Index, for FEB/MAR is 0.6. Such a value of MEI indicates a sea surface temperature distribution that corresponds to a weak El Niño. This suggests:

RAINFALL: There is a very slightly enhanced chance that total APR/MAY/JUN rainfall will be above normal in the WEST GIPPSLAND District, but there is little indication as to whether rainfall will be below, near or above normal in other Victorian Districts.

OVERNIGHT TEMPERATURES: There is a slightly enhanced chance that average APR/MAY/JUN overnight temperatures will be above normal in the CENTRAL District, but there is little indication as to whether overnight temperatures will be below, near or above normal in other Victorian Districts.

DAYTIME TEMPERATURES: There is a very slightly enhanced chance that average APR/MAY/JUN daytime temperatures will be below normal in the WESTERN District, there is a very slightly enhanced chance that average APR/MAY/JUN daytime temperatures will be above normal in the MALLEE, EAST GIPPSLAND, WEST GIPPSLAND and CENTRAL Districts, but there is little indication as to whether daytime temperatures will be below, near or above normal in other Victorian Districts.

The relationship between ENSO, the Indian Ocean Dipole (IOD),
and the rainfall, overnight temperature, and daytime temperature
at Australian Capitals over the forthcoming 30 days.

Click on the Australian Capital of interest (only Melbourne available at present)

30 DAY OUTLOOK FOR MELBOURNE:

Today's scientists talk in terms of the continent's large climate variability from season to season, and from year to year. What causes these fluctuations? They are, in part, connected with the climate phenomenon called the Southern Oscillation, a major air pressure shift between the Asian and east Pacific regions whose best-known extremes are El Niño events and La Niña events. The Pacific Ocean is a huge mass of water which controls many climate features in its region. Its equatorial expanse, far larger than the Indian or Atlantic Oceans, is critical to the development of the Southern Oscillation and the El Niño and the La Niña. The Multivariate ENSO (El Niño Southern Oscillation) Index, which combines the Sea Surface Temperature (SST) distribution across the Pacific with various features of the atmospheric circulation, is used to monitor the evolution of the El Niño and Southern Oscillation phenomena. The MEI is a bimonthly index which is calculated at the end of each month. The most recent MEI is 1.502 standard deviations. This reflects a strong El Niño event.

Another region of Sea Surface Temperature variability that impacts on Australian climate is that of the Indian Ocean. One mode of variability that appears to affect Australian rainfall, particularly the south east of the country, is the Indian Ocean Dipole (IOD). The IOD referred to here is defined by an index that is the difference between SST in the western (50°-70°E, 0°S-10°N) and eastern (90°-110°E, 10°-0°S) tropical Indian Oceans. A positive Indian Ocean Dipole Mode Index (DMI) occurs when the western basin is warmer than average and the eastern basin is cool and hence the DMI is positive. These regions were proposed in a paper by Saji et al. (1999) on the Indian Ocean Dipole that showed a modulation in Australian seasonal rainfall with DMI positive and negative years. The current Indian Ocean Dipole Mode Index (DMI) is -0.1 standard deviations. This reflects a mildly negative Indian Ocean Dipole.

Also impacting upon Australian climate variability is a phenomenon known as the Intra Seasonal Oscillation (ISO) (also known as the Madden-Julian Oscillation (MJO), after Madden and Julian, who first identified it in the early 1970s). They discovered that, at many locations in the tropics, surface pressure and upper atmospheric winds tend to go through a coherent cycle over periods of about 40 to 50 days. It has been found that a broad area of active cloud and rainfall propagates eastwards around the equator at intervals of between about 40 and 50 days. These are not strict time limits - research over the years has pushed the limits of the oscillation's period to between about 30 and 60 days. The Madden-Julian Oscillation (MJO) is presently operating in Phase 2. This is reflected in the near-equatorial enhanced convection being found over the over the western Indian Ocean. Following Phase 2, the region of enhanced convection often moves from the western Indian Ocean to the eastern Indian Ocean.

In Melbourne, at this time of the year, a combination of the MEI, the DMI, and the MJO Phase, such as what we have operating now, suggests, over the following 30 days:

RAINFALL: There is a 27% chance of it being wet, a 32% chance of normal rainfall, and a 41% chance of it being dry.

Wet Weather Dry Weather Normal Weather

OVERNIGHT TEMPERATURES: There is a 36% chance of warm nights, a 33% chance of normal overnight temperatures, and a 31% chance of cool nights.

Warm Nights Cool Nights Normal Nights

DAYTIME TEMPERATURES: There is a 37% chance of warm days, a 33% chance of normal daytime temperatures, and a 30% chance of cool days.

Warm Days Cool Days Normal Days

Home

Publications

Presentations

Climate of Victoria

10 Day Forecasts

Seasonal Outlook

Other Links