Looking Forward to the Week Mon 26th to Fri 30th March

This one is an easy one really as a huge High that is over Australia at present, rolls onto NZ but stays as a blocking High on both sides of NZ with low and variables winds and mainly fine weather over the whole of NZ for the rest of the week - something we have been missing recently - oh and I forgot to mention some sunshine!!

We should see some moderate Highs in the daytime but much colder nights than we have seen with frosts in inland sheltered areas.  It will tell you winter is coming this week! Daylight saving finishes next Sunday morning, when the nights will close in an hour earlier too!

On Wednesday - Thursday, the winds on the whole of NZ could be southerly and colder and east coast showers are possible.

Next weekend could expect to have some showers on Sunday if it travels as expected.

I am saving these to my site and then grabbing them into the post for easier reading and larger size.

All images here are from http://metvuw.com/forecast/forecast.php?type=rain&region=swp&noofdays=5

Todays Synoptic map:








These show the High as it spreads out over NZ and parks on both sides, keeping the Lows below NZ at bay with very little interference even to the South Island.  It is a particularly strong and large High which should bring settled weather over the whole week. You may have some sou-easterlies on the SI east coast at times, while easterlies will cover most of NI east coasts.  Some nor westers on the SI west coast.  But this will change through the week.

East Coast NI

Monday
Clear. High of 18C. Winds from the West at 10 to 20 km/h shifting to the SSW in the afternoon. Breezy.

Monday Night
Clear. Low of 10C. Winds from the SSE at 5 to 15 km/h shifting to the NNW after midnight.

Tuesday
Clear. High of 20C. Winds from the NW at 5 to 15 km/h shifting to the NNE in the afternoon.

Tuesday Night
Clear. Low of 11C. Winds from the ENE at 5 to 15 km/h shifting to the NW after midnight.

Wednesday
Clear. High of 20C. Winds from the SSW at 5 to 15 km/h.

Wednesday Night
Partly cloudy with a chance of rain. Low of 14C. Winds from the SSE at 15 to 20 km/h. Breezy. Chance of rain 50% with rainfall amounts near 1.3 mm possible.

Thursday
Overcast with a chance of rain. High of 19C. Winds from the SE at 10 to 15 km/h. Chance of rain 50% with rainfall amounts near 2.0 mm possible.

Thursday Night
Partly cloudy. Low of 12C. Winds from the ESE at 5 to 15 km/h. Chance of rain 20% with rainfall amounts near 1.0 mm possible.

Friday
Partly cloudy with a chance of rain. High of 19C. Winds from the ESE at 5 to 15 km/h. Chance of rain 50% with rainfall amounts near 1.3 mm possible.

Friday Night
Clear with a chance of rain. Low of 12C. Winds from the ESE at 5 to 15 km/h. Chance of rain 20% with rainfall amounts near 1.0 mm possible.

Tropical trouble brewing

The tropics have been somewhat quiet this year - especially when compared to the dramatic cyclone season last year.  However activity is about to step up with three zones showing signs of life.

Firstly, the Fiji Meteorological Service is warning of two potential risk zones for tropical cyclone activity - but the chance of a cyclone forming in either of these zones is considered "low" or "20% chance" according to the forecaster.

The first risk area will drift over Fiji on Tuesday and Wednesday - if a tropical cyclone fails to develop wind and heavy rain is still predicted.  Fiji has had serious and deadly flooding in the past few months - this tropical low will be unwelcome by many.

The other risk zone lies over Tonga, and like the Fiji risk zone it also comes with a low risk of actually producing a tropical cyclone - but the risk is still there for wind and rain regardless of if a storm is named.

But the highest risk lies directly to our north west, around the Coral Sea and Vanuatu.

Last week WeatherWatch.co.nz said the Coral Sea would be a high risk zone for tropical storm development in the coming two weeks - and as early as this coming weekend we may have a tropical cyclone forming near Vanuatu.

The predicted storm is expected to form over the Coral Sea - which means, to begin with, it will be Australian forecasters who predict, name and track it.  However cyclone outlooks for the Coral Sea only go out for 72 hours - and this storm isn't expected to get going until Saturday or Sunday.

Three of the most reliable models used by WeatherWatch.co.nz all indicate a significant tropical storm forming north of New Zealand - but only one has it picked coming directly towards us.

WeatherWatch.co.nz says those in the upper North Island should monitor the latest rain maps and weather news updates.

The weather news authority says the computer models need to have a couple more days of updates before a more concrete prediction for New Zealand can be made, but in light of the recent sub-tropical lows and northern floods and gales the accurate tracking of this potential storm will be very important.

In a nutshell

Two "low risk" zones for cyclone development in the next three days - one around Fiji the other around Tonga
No risk of a cyclone in the Coral Sea in the next 72 hours
WeatherWatch.co.nz has moderate to high confidence a cyclone or tropical storm will form in the Coral Sea this weekend
The risk of NZ being hit by the Coral Sea cyclone next week is considered "low at this early stage" - one reliable model shows a direct hit, while another reliable model shows it missing NZ well to our north east.  Still a lot of uncertainty - so watch this space for updates.
 
WeatherWatch.co.nz exclusive

 www.weatherwatch.co.nz

That is some photo Suez

Models still at odds over tropical cyclone path next week


WeatherWatch.co.nz forecasters say the various computer models remain conflicted about the path of a tropical cyclone next week - but one thing they do agree on is it's formation.

WeatherWatch.co.nz yesterday broke the news that a cyclone was expected to form well north of New Zealand, around Vanuatu this weekend.  It's unclear if the predicted storm will impact Vanuatu or deepen as it moves south away from the island nation.

All models WeatherWatch.co.nz uses - including two of the world's largest global models - show the storm developing and rapidly deepening into a severe tropical cyclone by Monday next week.

But while they all agree where and when it will form - all models are predicting a different path.

The most alarming model is coming from ECMWF - a European forecaster that last year nailed Cyclone Yasi's track towards Australia 10 days in advance - and also nailed the path of every tropical cyclone last season..

Since Sunday ECMWF has been predicting a major tropical cyclone to our north and then has it tracking south towards New Zealand around April 2, 3 and 4.  If their maps are anything to go by severe gales and flooding rains would be highly likely.

However they aren't the only organisation tracking this potential cyclone.

The ECMWF models are at odds with GFS - an American model, which tends to be more accurate short term than long term for New Zealand, in our view.  GFS has the low tracking to our north east, but fails to predict beyond a week - so a question mark still remains on exact tracking seven days from now.  Other models that do go out beyond a week, based on GFS data, also show the low tracking well to our north east - but close enough to be within our waters.

Australia's Bureau of Meteorogoly is halfway between the two mmodels - picking a tropical cyclone that will leave the Coral Sea and enter the Tasman Sea on Monday - but as a less intense storm than ECMWF.

WeatherWatch.co.nz said on Monday it would wait until Wednesday before making a more concrete prediction of for the upcoming tropical storm.

MetService has no information on the predicted low at this stage.

Either way it will be very interesting to see which model proves to be correct.

- WeatherWatch.co.nz

www.weatherwatch.co.nz/content/models-still-odds-over-tropical-cyclone-path-next-week