Old storm images

[GraemeWi]

Just to generate a bit of conversation on the forum I thought I'd post up a picture of one of the best storms I've seen in NZ.

I'm not sure of the exact date, but I saved the radar on Jan 16 1999. The storm caused flooding up in Hokianga and came south to Auckland where it caused quite a bit of damage in Pukekohe (flooded a couple of resthome units and washed away lots of soil)

The weather radar shows quite an interesting "S" shape.



I first noticed this storm sitting at home and hearing distant thunder that was nearly continious - I remember driving up to the top of a local hill and thinking "expletive!"

About the same time I was taking this picture (overlooking the Kaipara river valley) a tornado was reported in south head - directly behind the darkest area.



The storm produced virtually constant CGs as it approached, I remember getting hammered by very heavy rain in my car on the way back from the photography spot.

There was quite a long display of lightning afterwards - I think it was still going late at night, well after sunset.

Anyway, hope these are interesting to the folks out there.

G

[Manukau heads obs]

i remember seeing the anvil from that CB develop during the afternoon from here.....the top was blwon way off to the SW...and I told Bob Mcdavit at the time, something is going on!
it was the start of the upper level low that developed....which brought lots of CB's to here (south manukage heads) and the pukekohe area.
we too had lots of thunder etc.
the cb;s would build and build, then peak, then a new one would develop again.
at the time the dew point started at 22oC that day...it was called a super saturated air mass
there was so much cloud, it was quite dark at times, and during the heavy rain, you could not see much
we recorded 150 mm in 2.5 hours here,and pukekohe had a similar amount. (and we had had heavy rain only a few days before too)
but just to the north of me well over 200mm was recorded in the same period (and there was alot of property damage from slips)
the wife and I and the kids jumped in the car at 7am to check out the damage around the farm....
our drive way was a river at the time (it was still raining, but just starting to ease), and some low lying roads were under water.
in the twilight we could see alot of the farm was under water, and whole hillsdies were just torrents/sheets of water.
pity it was too dark to take pictures (and during the heavy rain you could not see much either)

[CbFan]

Also here:

http://www.metservice.co.nz/severe_weat ... 9899_2.asp

[Manukau heads obs]

ah, yes, it was the 21st
the 16th storms refered to here was CB's a few days before, and is the one i remember with seeeing the large anvil to the north of us, and yes we too got the cb's
i remember now,.,.,.,
and then after all that rain, it never rained again for over 6 weeks!

[NZstorm]

The summers of the late nineties were memorable for their heat and humidity.

I've looked back in my weather diary to refreash my memory.
Saturday the 16th was a fine hot day (max 30C, min20C). Active
cb's developed from 3pm out to the southwest and Northwest of Auckland.
Heavy showers/thunderstorms over Auckland during evening. 51mm recorded in city.

Thursday 21st started with drizzle and an overnight minimum of 22C.
Very high dewpoints. Weather cleared in Auckland but large cb's where
observed out to far NW and to SW after 3pm in direction of Pukekohe.
Neither storm affected the Auckland metropolitian area.
But they both made headlines on TV/Newspaper for property damage. The winds
where from the NE on this day and I am sure both storm events
developed on seabreeze convergence zones.

[GraemeWi]

I've had a good hunt through my PC and found some more radar images of those two days:

16 January 1999 3pm


16 January 1999 6pm


21 January 1999 6pm


G

[NZstorm]

Actually there was quite a bit of thunderstorm activity during the middle
of january 1999.

From my weather obs

Friday 15th
Persistent cbs through west (wiatakeri) with thunder. Humid Max 28C

Sat 16th
as documented above...thundery end to day

Sunday 17th
Afternoon buildups. I drove over to Kemu to get close to quite a nice
storm with some very close CGs. Also, another significant Thunderstorm
over the Manurewa to Howick area on the same afternoon. Good day
for photographing.

Then only isolated showers untill the big Thunderstorms of the 21st.

[Thunder]

Hi There

Haven't said anything in a while but still I check in every day to see whats happening. That image looks really awsome! (the photo), just wish I was there, love that dark underbelly of the cloud and being able to see clearly how low it is to the ground. Oh well I'll have to wait untill spring / summer this year for a thunderstorm here in Cantab unless something weird (spelling?) happens this winter, can't wait until something happens!

Aaron Wilkinson

[NZstorm]

The upper air soundings for that period look interesting.
Moisture laden soundings with lifted indices down to -4.1.
Not alot of wind shear though. But the problem with upper air soundings
they are 12 hours apart which is a long time in Meteorology.
No doubt freash sea breezes would have created localised wind shear.
Cheers

[GraemeWi]

Would you be able to post up a copy of the soundings? Raw (TTAA) if you have them, would be interesting to work out the k-index on that day!

Cheers,

Graeme

[NZstorm]

Hi Graeme

K index for the 21st January 1999 was 38.
Precipitable water was 52mm.

[NZstorm]

STID = NZWP STNM = 93112 TIME = 990120/2100
SLAT = -36.78 SLON = 174.63 SELV = 27.0
TTAA 2200
PRES TMPC DWPC DRCT SPED HGHT
1008.00 24.40 22.30 60.00 2.00 -9999.00
1000.00 22.40 21.00 -9999.00 -9999.00 102.00
925.00 19.20 18.50 -9999.00 -9999.00 779.00
850.00 15.80 15.20 -9999.00 -9999.00 1506.00
700.00 7.80 5.80 -9999.00 -9999.00 3138.00
500.00 -8.90 -19.90 -9999.00 -9999.00 5830.00
400.00 -19.50 -27.50 -9999.00 -9999.00 7530.00
300.00 -31.50 -71.50 -9999.00 -9999.00 9620.00
250.00 -39.90 -76.90 -9999.00 -9999.00 10880.00
200.00 -49.30 -9999.00 -9999.00 -9999.00 12380.00
150.00 -61.50 -9999.00 -9999.00 -9999.00 14210.00
100.00 -73.10 -9999.00 -9999.00 -9999.00 16640.00
PPAA 2200
PRES DRCT SPED
850.00 350.00 7.00
700.00 325.00 6.00
500.00 325.00 7.00
400.00 320.00 15.00
300.00 275.00 5.00
250.00 300.00 6.00
200.00 5.00 4.00
150.00 355.00 6.00
100.00 310.00 2.