Jump to content
Snow?
Local
Radar
Cold?

J07

Members
  • Posts

    802
  • Joined

  • Last visited

Posts posted by J07

  1. I think New Zealand's prevailing wind direction is more of a direct westerly rather than a south-westerly, but they do seem to spend a lot more time under the influence of airmasses of south-westerly origin which essentially amounts to the same thing.

    Probably you are right, more westerly than southwesterly. WSW probably covers it!

    But it's hard to measure because anywhere you look will have local topographic impacts.

    For a maritime, mid-latitude country New Zealand is surprisingly sunny. The main reason for this lies in the topography. There are variable weather patterns, and in every pattern somewhere in the country will do pretty well for sunshine. This means that over three decades things even out and you get relatively high sunshine hours. An interesting comparison is New Plymouth vs Napier. Same latitude, but one is on the east coast and the other on the west, yet their sunshine hours are very similar (maybe only 100 hours different).

    The sunniest spots though are the NE corners of both islands (Nelson/Marlborough on the SI, Bay of Plenty/ some of Gisborne on the NI) which both can consistently record 2500 hours of sunshine each year. From experience, living in a spot with 2500 hours of sunshine is very different to 1500 hours of sunshine. It's never so sunny that it gets "boring", but being able to bank on ~5 hours of bright sunshine on an average winter day (instead of 1-3 hours) is really significant. I've sat through winter months with frosty mornings, daytime highs of 14C and over 200 hours of sunshine. It's a very pleasant existence!

    My experience from living in both countries is that there are fewer "so-so" days in NZ than in the UK. In the UK the relentless weaks of "nothingness" would drag on seemingly without end! Here a small change in wind direction will suddenly flip your location from being exposed to the crap weather to being brilliantly sunny. For Wellington this is S->SW usually. To our south there is no land at all (until Antarctica thousands of km away), but to our SW is the entire South Island with all its mountains so the worst we get from them is mid or high level cloud.

    For us, if the flow at 850hPa is W through to SW, the chances of us getting any precipitation of significant cloud is low. It needs something major happening at upper levels to break this rule.

    The higher (and conveniently situated) mountains here make a bigger difference than they would in the UK. So today I think the coldest place was Darfield (cold, cloudy miserable 10C) and the warmest place was Hokitika (200km west, sunny and 26C). Between them is a series of ranges getting close to 3000m in height.

    The regularly succession of summertime anticyclones (November-April) probably does help us, but it does not guarantee sunshine and in Wellington I would prefer a cyclonic westerly flow to an anticyclonic situation where we end up stuck in 30kt northerlies and cloud all day long trapped beneath the inversion.

    We spend plenty of time in moist tropical maritime flows. Far too much time if you ask me. This summer was bad. One evening I went out and it was 22/22 and drizzling. Simply disgusting weather!

    Anyway, there is something kind of appealing about Britain's cloudy weather! Sounds crazy I know. But I visited the UK last summer and the whole country (northern France also) seemed to be bathed constantly in a wintry light. This is dramatically different to the intense, bright light we get down here with vibrant colours and very high visibilities. To me it made the country look bleak, but also something like a watercolour painting. I would find it easier to live there than somewhere in Western Australia.

    As an aside, apparently the UV index here is 40% higher than at equivalent latitudes in the northern Hemisphere. I don't know how to compare with the UK latitude, but a rough estimate suggest that it could be something like 60-100% higher here than in the UK. So coupled with the raw sunshine hours being higher, the overall exposure to UV here must be way beyond what you would get in the UK.

  2. It's the 1st of May (equivalent to 1st November in Northern Hemisphere) and the national high was 26C in Hokitika on the West Coast of the South Island.

    We've had a blocking high over us for a while, with some very dry air above the inversion. The 850hPa temperature/dewpoint on Friday was 6C over -40C.

    Approaching from the north has been a low, typical of La Nina summer/autumn, bringing dewpoints of 18C to the north and quite strong easterly winds.

    Probably the weather will stay unsettled but mild for the coming days. We've already had a few cold outbreaks this autumn, but interspersed with long sunny and warm spells (like today).

  3. No longer a TC.

    STORM WARNING 689

    This affects ocean areas: SUBTROPIC FORTIES and PACIFIC

    AT 290000UTC

    Low 972hPa, former Cyclone BUNE, near 33S 175W moving southsoutheast 20kt.

    1. Within 180 nautical miles of low in sector from southeast through southwest to north: Clockwise 45kt rising to 60kt next 6-12 hours.

    2. Outside area 1 and within 180 nautical miles of low in northeast quadrant: Clockwise 55kt.

    3. Outside areas 1 and 2 and within 360 nautical miles of low in eastern semicircle: Clockwise 40kt.

    4. Outside areas 1 to 3 and within 300 nautical miles of low in western semicircle: Clockwise 40kt.

    Storm and gale areas moving with low.

    This warning cancels and replaces warning 686.

    Issued at 1:24pm Tuesday 29 March 2011

  4. Suspect Bune will still be classified as a TC at 06Z, 12Z and 18Z. Probably 00Z also, but likely that 06Z will re-classify.

    It is looking to make a direct hit on Raoul Island. The DOC workers there have been notified, and warned of sustained winds close to 100km/h and gusts of 150km/h. The centre is likely to be overhead at 12Z! So provided the AWS does not fail we will find out for sure what the central pressure of this TC is, which in this part of the world (very sparse observations) is really rare!

    Current warning (00Z today):

    TCSTORM WARNING 661

    This affects ocean area: SUBTROPIC

    Tropical Cyclone BUNE [975hPa] centre was located near 27.4 South 179.1 West at 280000 UTC.

    Position Fair.

    Repeat position 27.4S 179.1W at 280000 UTC.

    Cyclone is moving southeast 12 knots.

    Expect sustained winds of 60 knots close to the centre easing to 55 knots by 281200 UTC and then easing to 50 knots by 290000 UTC.

    Expect winds over 48 knots within 100 nautical miles of centre.

    Expect winds over 33 knots within 220 nautical miles of centre.

    Forecast position near 29.7S 177.8W at 281200 UTC

    and near 32.1S 176.5W at 290000 UTC.

    This warning cancels and replaces warning 654.

    Issued at 1:26pm Monday 28 March 2011

  5. Would like to know at what rate do UV levels increase with height? This is an important consideration for aynone venturing into the fells where due to closer proximity to the sun and less shelter you are much more susceptible to sunburn as I can vouch for on many an occasion..

    Don't recall the exact relationship but it's so slow you don't need to worry about it in the UK unless you're going up the very highest Scottish hills. Snow cover is probably the bigger concern.

    I don't understand the rush for sunscreen. You should give your skin some chance to feel the sun in Spring without blocking out its useful impacts immediately!

    The increase is 4% per 300 hundred metres.

    So assuming a day with a max noon clear sky UV of 4, if you went up Scafell the UV at the summit would be 4.5. It would be 4.7 on the summit of Ben Nevis.

    I think you've no reason to worry!

    For an example of how bad it could get, climb Mt Ruapehu down here on an early day in January and you could expect a UV index of 20 at the summit (assuming 13 at sea level) and that's not taking into account reflection from the permanent snow cover.

    It gets even worse when you look at places such as Papua New Guinea or the Andes, where I've heard quotes of UV index getting up to 25!

  6. Epicentre closer to the city buildings weakened by the previous one and the time all make for a very bad experience. If I remember correctly Christchurch hasn't had a lot of earthquakes and was considered "relative" earthquake free compared to the rest of New Zealand. There was speculation that a fault nearby had re-activated but this more likely to be an aftershock from the previous one.

    Yes, Wellington is always considered to be the most worrisome. So important buildings here are built on base isolators, and the supports for motorways are encased in steel. The city is on the continental divide, and has about five faults running through it (one is a 10min walk from my house). But we've barely had a jolt here for ages.

  7. 65 confirmed dead....

    Prime Minister John Key confirms 65 dead "and that may rise".

    Speaking on his arrival at Christchurch Mr Key said: "We may well be witnessing New Zealand's darkest day".

    He said 180 police were working on the ground with an extra 200 on their way. There were also 350 military personnel there and another 250 on their way.

    Forty members of an Australian urban search and rescue team were on their way from Australia and New Zealand had accepted help from America as well.

    "We may be witnessing New Zealand's darkest day."

    He described it as a "scene of utter devastation''.

    The earthquake struck at a much worse time than the last one with more people were out on the streets this time.

    "We will get through this. New Zealand will regroup, Christchurch will regroup."

  8. They are small but the configuration is crucial, running perpendicular to general prevailing westerly flows.

    As TWS mentioned the main ranges in NZ's South Island are similarly convenient in running in that direction, though they are much higher.

    eg the driest place in NZ in 2010 was Clyde, just east of the Alps, with 389mm of rain in the year. The wettest place in 2010 was Cropp River, just west of the Alps, with 12374mm of rain in the year. So a site east of the Divide was 31 times drier than a site west of the Divide.

    Another example was this previous weekend, it was 41C in Timaru (east coast) with a hot dry northwesterly whilst 100 miles directly west on the West Coast in Haast it was hosing down and 19C.

    So I don't think the Pennines are all that remarkable. There are probably many small ranges across the world that have a similar effect, provided they are in the mid or high latitudes.

    Topography makes weather interesting for me. I like the contrasts in coastal California. You can cross their coastal ranges very quickly on the highway, and what a difference there can be in summertime just an hour away!

  9. The east of NZ is very changeable all the time, things change there much faster and more drastically than in the UK. Timaru seems to get it a lot. An example would be a few years back in June it was 20C at midday, then the following midday it was snowing.

    This time around, after breaking the record yesterday and hitting 40.3C, the maximum today was a mere 15C, the second coldest place in the country and a rather enormous difference of 25C in consecutive daily maxima!

  10. Temperatures hit 40 degrees in Timaru

    <h2 style="margin-top: 5px; margin-right: 0px; margin-bottom: 5px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; color: rgb(51, 51, 51); font-family: Georgia, Times, serif; font-size: 16px; font-weight: normal; "></h2>CHRIS SCHULZ

    South Island residents are sweltering in record-breaking temperatures that are hitting 40 degrees - and Cylone Yasi is to blame.People living in Timaru today suffered through a high of 40.3 degrees and the MetService believed this to be the hottest temperature recorded in the region since 1962.

    "It's quite tricky being outside - you're likely to get thirsty very fast," said MetService forecaster Allister Gorman.

    Dunedin residents were also sweltering in 35 degree heat - a temperature believed to have broken the region's previous record of 32.

    And Oamaru and Christchurch residents were basking in 36 degree heat in what Gorman called "a classic Canterbury nor'wester".

    "Essentially what we're getting is a lot of hot tropical air from Cyclone Yasi. That air has come from the remains of the cyclone across the Tasman and impacted on the Southern Alps."

    There is good news: The soaring temperatures were accompanied by low levels of humidity, and Gorman said the region should cool down by midnight.

    - Stuff

  11. 8 inches in 8 hours, that's some rainfall!

    According to this http://www.stuff.co.nz/national/4598281/Wilma-blows-out-of-country some places saw 2 months of rain in 12 hours.

    Compared with Bola (March `88) this was small fry though! From Wikipedia:

    Cyclone Bola created some of the heaviest rainfall totals for a single storm in the history of New Zealand, with some locations receiving more than half of their annual rainfall totals from the storm. While the cyclone passed north of the island, a strong easterly flow over the North Island contained the interaction between moist air from Bola and drier air from the ridge to its southeast. In the Gisborne region, the flow resulted in the heaviest rainfall totals, when the moisture ascended over the region's western mountainous areas and condensed into precipitation. One station recorded 419 mm (16.5 in) in a 24 hour period.[6] The maximum rainfall total attributed to the storm was 917 mm (36.1 in), reported at a station near Tolaga Bay.[1] Heavy rainfall totals of up to and over 300 mm (12 in) were observed in the regions of Auckland and Northland.[6] The cyclone is the largest to be recorded in 93 years of rainfall records. As such, it had a large and lasting effect on the rivers of the area when it deposited a large amount of sediment, as recorded in the sedimentary record of Lake Tutira.[11] Shortly prior to losing its identity, the remnants of Bola also dropped 100–200 mm (4–8 in) of precipitation on the South Island of New Zealand.[]

    shok.gif

  12. Latest Wellington warning (no more Hurricane force winds near the centre):

    Also attached MetService progs. The first is 1PM analysis, the next is the prognosis for 1AM this morning.

    Wilma despite weakening will remain classed as a Tropical Cyclone until tomorrow morning (just over 12 hours from now), because cyclones don't get re-classified at night. Though it's possible they re-classify it at 06Z (7PM, two hours from now). We'll see.

    STORM WARNING 501This affects ocean area: SUBTROPIC

    Tropical Cyclone WILMA [980hPa] centre was located near 30.5 South 172.2 East at 280000 UTC.

    Position Poor.

    Repeat position 30.5S 172.2E at 280000 UTC.

    Cyclone is moving southsoutheast 25 knots.

    Expect sustained winds of 55 knots close to the centre easing to 50 knots by 281200 UTC.

    Expect winds over 48 knots within 60 nautical miles of centre.

    Expect winds over 33 knots within 220 nautical miles of centre in the southeast semicircle and within 100 nautical miles of centre in the northwest semicircle.

    Expect winds over 33 knots within 220 nautical miles of centre in the sector from north through east to southwest and within 100 nautical miles of centre in the sector from southwest through northwest to north by 290000 UTC.

    Forecast position near 34.5S 174.5E at 281200 UTC

    and near 39.5S 178.8W at 290000 UTC.

    This warning cancels and replaces warning 497.

    Issued at 1:42pm Friday 28 January 2011

    post-7526-0-53458000-1296186420_thumb.pn

    post-7526-0-69987400-1296186436_thumb.pn

  13. MTSAT imagery: http://www.goes.noaa.gov/sohemi/sohemiloops/shirgms.html

    And latest Wellington warning:

    HURRICANE WARNING 490This affects ocean area: SUBTROPIC

    Tropical Cyclone WILMA [950hPa] centre was located near 26.1 South 172.9 East at 270600 UTC.

    Position Good.

    Repeat position 26.1S 172.9E at 270600 UTC.

    Cyclone is moving southsouthwest 10 knots but expected to be moving southsoutheast 15 knots at 271800 UTC.

    Expect sustained winds of 80 knots close to the centre easing to 65 knots between 271800 UTC and 280600 UTC.

    Expect winds over 63 knots within 20 nautical miles of centre.

    Expect winds over 48 knots within 30 nautical miles of centre.

    Expect winds over 33 knots within 220 nautical miles of centre in the southeast semicircle and within 100 nautical miles of centre in the northwest semicircle.

    Forecast position near 28.1S 171.6E at 271800 UTC

    and near 31.3S 172.3E at 280600 UTC.

    This warning cancels and replaces warning 487.

    Issued at 7:55pm Thursday 27 January 2011

  14. First warning on Wilma from Wellington:

    HURRICANE WARNING 487

    This affects ocean area: SUBTROPIC

    Tropical Cyclone WILMA [930hPa] centre was located near 25.3 South 173.3 East at 270000 UTC.

    Position Poor.

    Repeat position 25.3S 173.3E at 270000 UTC.

    Cyclone is moving southwest 10 knots but expected to be moving southsouthwest 15 knots at 271200 UTC.

    Expect sustained winds of 100 knots close to the centre easing to 80 knots between 271200 UTC and 280000 UTC.

    Expect winds over 63 knots within 20 nautical miles of centre.

    Expect winds over 48 knots within 30 nautical miles of centre.

    Expect winds over 33 knots within 200 nautical miles of centre in the southeast semicircle and within 100 nautical miles of centre in the northwest semicircle.

    Forecast position near 26.2S 172.2E at 271200 UTC

    and near 29.2S 171.2E at 280000 UTC.

    This warning cancels and replaces warning 485.

    Issued at 1:39pm Thursday 27 January 2011

×
×
  • Create New...