Autumnal Feel to the Weather

[NZ Thunderstorm Soc]

Today after a warm morning, a cold southerly change came through and in the afternoon the temperature was down to 14ºC after a high of 24.6ºC around noon.
Last WE we lit the fire as it was a bit cold.
Today, I gathered 2 colendars full of mushrooms and some of the leaves of the deciduous trees look as though they are turning.
Looking forward to the autumn colours

JohnGaul
NZTS

[NZstorm]

yes, the wheels came off NZ's summer mid Feb but this weekend was superb in AK. Week ahead looks patchy with high pressure trying to establish over NZ but another frontal attack from the SW early week. The GFS suggests some unstable weather over the NI to end the week.

[spwill]

There's been very persistant High preasure centered in the Tasman Sea of late allowing cooler flows onto NZ .
Might be a change in pattern comming up next week with a warmer more humid flow onto NZ.

[NZ Thunderstorm Soc]

Even though autuminal, there could be a, with this La Nina pattern, a Indian summer Scenario development, with lots of boring weather,sadly
More so next month after the demise of daylight saving.

JohnGaul
NZTS

[TokWW]

Definitely cooler evenings and easier to sleep...

[npfield]

Last night was pretty warm in auckland..I had to have the fan going
Last few days have been nice and warm, I was sitting out in the sun today at lunch felt more like a summers day. Heres hoping for an indian summer for the duration of autumn

[sw_windbow]

Cooler alright, to me it felt like the wheels came off at the end of Feb/start of Mar with that significant rain event. Since then it's felt like each day has had 10 degrees sawn off either end.

[NZ Thunderstorm Soc]

Maybe a few autuminal tornadoes off/along the Canterbury Coast tommorow?
Wouldn't that be nice.
Noticed some beefy showers off the Otago Coast this afternoon.

JohnGaul
NZTS

[Gary McConnochie]

Yes I see Metservice have possible tornados forecast for Mid-South Canterbury tomorrow.

I dont think I have seen that in the forecast before?

[spwill]

Cooler change arrived in Auckland about 5pm today but with a very small drop in temp, from 23C to 20C

Yes I see Metservice have possible tornados forecast for Mid-South Canterbury tomorrow.

Just in the convective/TS outlook.

[Ryan Thomas]

Was excited till I read low risk of thunderstorms then saw the range to extend to just south of Christchurch

[sw_windbow]

There hasn't been a good nor-wester for a while in Dunedin but that looks set to change with a forecast of 65 km NW with 120 km gusts tomorrow morning.

[David]

A heavy shower at my school today starting about 10.20- I estimated about 6-7mm fell, but the Eastern Beach weather station has 5.6mm. Only 2.4mm here at home about 2km away. Also just had some large rain drops falling for a minute recently with some dark clouds around. Gentle breezes here today, so felt quite warm with the 24C we've reached this afternoon. Our cooler run of 11-14 degree nights ended last night with a low of 17.

[Manukau heads obs]

David,that was a strange shower.....sort of a weak easterly surge type event...
we had a strange situation here last night....a NE surge pushed against a SW coastal wind....and the cloud line sure got swirly at the base....small swirls and small funnels briefly appearing

[Storm Struck]

Sure was great to hear the roar of the NWer this afternoon in the trees, havnt seen a strong to gale force NW like that since probly January.
Was quite warm this morning when the sun broke through with a NW breeze, havnt seen the weather yet but id say around 26-27C today not bad for early autumn.
Wont be much with that southerly change, but watch for some good strong gusts when she arrives.
Must be some interesting weather coming up surly Oh yeh thats right easter is coming up usually a rough weekend across the country.
Cheers
Jason.

[mikestormchaser]

Yes was a nice day alright, was again cool this morning, but did notice some random bursts of warmth in the wind early this morning from the NW was great!!
Not sure if anyone has pointed it out but CRT seems to be abit stuck at the mo.

[NZstorm]

A heavy shower at my school today starting about 10.20- I estimated about 6-7mm fell

There was a heavy shower here at dawn. Small dewpoint depression (saturated air, dps 17C) and very unstable air under 7000ft behind the precip. Just goes to show heavy rain can fall out of low top clouds.

[tich]

The southerly arrived in Chch this evening without a bang - skies are cloudless and even the wind (which is often gusty with a southerly change, eg on Sunday) is only moderate, especially in comparison to the gusty northwesterlies we had this afternoon.

[Thunder]

Maybe a few autuminal tornadoes off/along the Canterbury Coast tommorow?
Wouldn't that be nice.
Noticed some beefy showers off the Otago Coast this afternoon.

JohnGaul
NZTS

The way you say that John, "Maybe a few autuminal tornadoes off/along the Canterbury Coast tommorow?", lol. Cracks me up. I can see you saying it now. Honestly though would've been cool to have a tornado or two, the particular scenario looks to of not pulled off however but that's understandable. Low risk was mentioned, the media gets a bit jumpy about these things.

CRT is back now.

Cheers
Aaron

[NZ Thunderstorm Soc]

MetService had a couple of interesting scenarios on todays wind change which could of lent to interesting weather with the change but owing to the fact that surface barometer pressures were'nt all that low enough, even a low chance of something like that wouldn't of eventuated, anyway.
Lower than 1000hpa would of done the trick, well maybe?

JohnGaul
NZTS

[Paul Mallinson]

John, I think the problem was that the dew points never rose high enough. Models where forecasting dewpoints to rise to about 11 or 12C along with temps in the mid+ twenties but they only rose to about 6C (in the westerly flow). One had to put some faith in the guidance since morning dew points started out as low as -7C at 7am in Timaru for example (in the warm dry northwesterly). They did rise as the forecast trend went for, but not high enough. They rose in the face of a strong west to northwesterly due to a band of warmer moister air (higher Theta W or Wet Bulb temperature) moving up the west coast. A number of stations (especially in Southland and Otago) rose from those rather low negative dew point values during the morning. Also, the west to east convergence zone just south of Banks Peninsula does appear to have developed (northwesterlies to the north and more westerly winds to the south). But the moisture wasn't high enough. When the southwesterly change came through, the dew points did rise to about 11C but by that time it was to late and the earlier support from a short wave trough going over was gone, with it lying to the northeast up over Marlborough. The other point of faith in the models was to accept that for a time the ascent through quite a deep layer over the small threat area (up to about 400 hPa) would occur and it was forecast to be was either moderate or weak but not subsident (downward). The guidance did show the downslope flow of the westerly to the west of the area.

So given that quite a few things had to come together in a small window of time and location, we opted for a low thunderstorm risk. The amount of moisture was probably the greatest uncertainty. There was lots of shear with the situation and if a thunderstorm had developed, then there was that risk of a tornado.

(From memory, the tornado that badly damaged that 100+ year old farm house in coastal Otago about a year or two ago occurred in rather similar circumstances, but the moisture was rather higher.)

Cheers,

Paul

[NZstorm]

Looking like we may see a few afternoon heat/convergence showers over Auckland tomorrow and Friday, possibly heavy Friday.

Weekend looks like it will be fine for Auckland with a warm fohn SE wind.

[spwill]

few afternoon heat/convergence showers over Auckland

The air is on the dry side here today (dewpoints around 13C) . Has been a fine warm day.

I see there's a few showers over Coromandel way this afternoon.

[jamie]

Much more humid south of the bombays. Just drove to Hamilton and there are alot of small cu with dark bottoms about. Even got a few spits from one in Meremere.

[Manukau heads obs]

bit of a easterly surge coming across the area with a few weak light showers...I see...
nearly half way through march and only 17mm so far here, and no rain in sight for the next 10 days now (on the current model runs)
dang.....we need follow up rain now to keep the green growth going and newly sowed pastures growing!