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#1447137 - 03/01/2018 16:59 Ideal set-ups for severe storms to hit your location
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 2034
Loc: Brisbane Western Suburbs
Seeing and sharing some of the frustration with the recent storms avoiding Brisbane I thought it might be worthwhile to discuss your observations of the ideal set-ups for severe storms to hit your location.

The far western suburbs of Brisbane can be a frustrating place for severe storms. Storms often split on approach, slide by to the west through the Brisbane Valley, north-west through the upper Brookfield ranges or to the south-east toward Logan and the northern Gold Coast.

Below are some of my observations for severe storms in this area. I've picked hailstorms because they are usually most indicative of severe multi-cell or supercell activity. My dates/years may be a little off.

1980s:
* Jan 18 1985 - Infamous '1985 hailstorm'. Triple-point set-up with NE'lies, trough to west and southerly change. Supercell forms near border ranges in the area north of Urbenville and travels sharply NE to the coast. Extreme winds, cricket-ball sized hail and very heavy rainfall. Jees I wish I'd seen that one.
* May have been more in the 1980s but didn't personally witness.

1990s - There were a number of hailstorms that hit this area. There was a nasty one that delivered golf-ball sized hail that came from the SW sometime in the mid-late 1990s. According to Coxy there were a few of these in the 90s. I can also remember a hailstorm hitting during the Easter period in the late 90s but fuzzy beyond that.

2000s -
* Hail to 4cm on 27/11/05. A whole band of discreet supercells with the one hitting here coming from the W/SW.
* In 06 or 07 there was also small hail (2 cm) that came from one bizarre storm that tracked all the way south from the Sunshine Coast.

2010s -
* Hail to 2 cm in November 2011 from a tiny cell that popped up overhead and tracked SW just before a big gust front hit.
* Hail to 6 cm on on November 18, 2012. The previous day there had been a severe cell sweep through Brisbane in the morning (the one that everyone bagged the BOM for not warning), giant supercells on the Darling Downs in the afternoon spreading into thundery rain and an epic light show at night. On Sunday 18th there were storms firing early and moving across all of SEQ. Then after it cleared one last cell developed around the border ranges north of Urbenville and tracked sharply NE intensifying just before reaching here and dumping huge amounts of large hail. Was easily the most severe storm in 15 years for this area.

So from my own observations over the last few decades it appears that severe storms with hail roughly follow this pattern:

Average occurrence (from 1990s onward):

* Tiny hail - Every year or two years
* Small hail - Twice a decade
* Large hail - Once a decade

Average direction:

* We don't get hailstorms from:

Activity moving in from the west or general south-west. It also weakens or splits.

Also, big systems that come from the south with southerly changes (e.g. Gap storm 08, Brisbane supercell 14, most big southerly change storms) often miss here because they are already coastal and trend NE as right-movers so they affect southern suburbs and CBD rather than the western or they become patchy and 'jump' over this year as they re-consolidate off the ranges before strengthening to the north.

* We do get hailstorms from:

Most usually from discrete long-track supercells that have formed on the border ranges in the sweet spot between Oakington and Urbenville. This allows right-moving supercells in a NE'ly flow to track into this area (1985, 2012).

We also seem to get hailstorms from more bizarre storm formations/movement than typical patterns.

Average timing (from 1990s onward):

Always seems to be November, particularly since the 2000s.

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#1447142 - 03/01/2018 17:24 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 2034
Loc: Brisbane Western Suburbs
OTHER THOUGHTS:

Some other thoughts worth discussing regarding storm tracks, severity and frequency in SEQ (within 150 km of Brisbane):

Synoptic precursors for severe storms in SEQ:

After some simplification, Callaghan’s analysis leads to essentially four classes of severe thunderstorms in the region, based on broad synoptic pre-cursor types as follows (Harper and Callaghan, 1998):

Type A: SE Change (23%)
Type B: Strong NW Flow (17%)
Type C: Weak NW Flow (43%)
Type D: Other (17%)

Callaghan also proposed a strong association between both storm intensity and track as a function of the regional topography; these being related to:
• the highland regions to the south and west providing elevated convective heat sources and hence buoyant air;
• for storms to reach the coast, a generally westerly steering current at middle levels and providing vertical wind shear is needed to sustain severe storms;
• low level convergence on the coastal plain which compensates for the loss of buoyancy in moving off the ranges;
• the interaction between the sea breeze and frontal/trough systems generates and intensifies severe thunderstorms in the populated coastal plains region.


I think this explains a lot why we often struggle to see really severe storms in Brisbane. The highest likelihood of severe activity in SEQ relates to NW flows - how often do we get these and how often do these make storms just slide south of Brisbane. Southerly changes are also not as common, usually as the timing is off. So many of our set-ups account for just 17% of what normally results in severe activity. Unfortunately many of these set-ups are not favourable for our area as mentioned in the bullet points above because storms lose buoyancy moving east/NE off the ranges and need excellent shear and low-level convergence to maintain strength.

Severe storm trends in SEQ (less frequency and spring-based?):



A lot of people seem to be saying that we get less frequent storms and severe storms in Brisbane than before the 1980s. Even as someone who has avidly followed storms since the 1990s I think we are seeing less severe storms overall and they usually seem to happen in November.

According to Harper, Granger and Hall, the occurrence of damaging thunderstorms affecting SEQ was 27% in Nov, 31% in Dec and 16% in Jan (dataset ends in 1995). I know that for Brisbane though we now generally seem to get all our severe storms in November before a more tropical, rain-bearing pattern sets in during December and January. Inland areas much further west get the activity and we seem to get very little before a slight re-occurrence in the autumn months. That's why this storm outbreak in Christmas/NY has seemed very unusual to me.

Relationship between SOI and SEQ storms:



Another interesting point of discussion is the relationship between SOI and SEQ storms. A high SOI (suggestive of a major La-Nina) results in significantly less damaging storms in Brisbane (e.g. during the 1970s La Nina period). This might mean heavy rain but not hail. I can confirm that in the epic 2010/2011 La Nina we only had two severe storms in SEQ in spring/summer up to the 2011 floods. However, low SOIs seem to have a similar effect on limiting storm activity (probably too dry). I guess it's interesting that this year we have a weak La Nina and yet we're seeing probably one of our better storm seasons in years (very active October and an excellent outbreak in late Dec/early Jan).

Where storms hit most in Brisbane:

These maps come from Dr Joshua Soderholm, who has done some excellent research on severe storms in SEQ. I think he may also be the guy behind the UQ hail research. His thesis 'The Mesoscale Atmospheric Environment of South-East Queensland Warm Season Thunderstorms' explains so much and goes into great detail, although I'm not sure I understand all of it haha.

These maps show which areas in the greater Brisbane area get severe storms and hail. Do these match with your own observations? For my area they suggest between 2002-07 there were only about 1-5 severe thunderstorms which matches very closely with what I remember of that period. Yet, based on 2 decades of hailstorm radar analysis we middle on the average annual frequency of hailstorms (0.3) which actually puts us better off than many other parts of Brisbane. So we get less severe storms out here but a higher chance of hail when they make it through?


(2002-07 only)


(Annual frequency of hailstorms - Derived from 19 years of radar data)


Edited by Nature's Fury (03/01/2018 17:33)

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#1447145 - 03/01/2018 17:33 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Warwick Eye2Sky Offline
Weather Freak

Registered: 31/08/2010
Posts: 854
Loc: Warwick, QLD
Great thread Natures Fury. Yes, I think we are in the same boat. Warwick seems to miss out also. It is interesting to see Allora in a little hole in the hail map above. Certainly does not represent the past few days, I guess there are always exceptions however.
So, do you or anyone else have an opinion on why, more often than not, Warwick misses out? Does anyone know if Warwick itself (CBD) has ever been struck with a major hailstorm?
Thanks. smile
_________________________
Michael - your eyes to the west.

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#1447152 - 03/01/2018 17:54 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Brett Guy Offline
Meteorological Motor Mouth

Registered: 05/10/2010
Posts: 5019
Loc: Bently Park, Cairns
As a Cairns resident I would say the ideal set up would be to move to SE QLD. We have had One storm this year. 2 months ago. It lasted all night which was exceptional as they normally last half an hour but that was it. one all night rumbler. No strong winds or excessive rain or hail or anything else. Generally the tablelands is good(not this year) but the topography means 90% of storms that do move east die out as soon as they fall of the ranges west of cairns. Bad topography combined with an air mass that is way to stable through the upper levels means we miss out unfortunately. It is not something I would have imagined before moving here.
And I also have to note that the term 'severe' is relative in my experience. The few systems I have seen labled as 'severe' up here would barely raise an eyebrow in SE QLD.

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#1447153 - 03/01/2018 17:56 Re: Ideal set-ups for severe storms to hit your location [Re: Warwick Eye2Sky]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 2034
Loc: Brisbane Western Suburbs
Hey Warwick, I'm no expert but a few thoughts:

Is Warwick well-placed to receive severe storms?

Warwick is topographically in a good spot being in a valley right in the middle of the ranges. That means you have good buoyancy, especially for storms tracking into your area not to lose severity (especially the big lines coming from the west that so often weaken on approach to Brisbane). However, what might not help your case is that your area is a storm formation zone -- storms often form in your region and move N toward Toowoomba or NE toward the Scenic Rim so you might only be struck by storms in their infancy rather than at their most severe.

Does Warwick receive severe storms?

I had a quick look at this:

http://hardenup.org/umbraco/customContent/media/2133_Severe%20Weather%20ArchiveLR.pdf

pp. 88-206 were compiled from records kept by Jeff Callaghan John Butler (ex Senior Severe Weather Forecasters from BOM) and only appeared online earlier this decade. I did a random sample from 2000-2007 and found that Warwick has seen its fair share of action. One issue though is whether they consider 'Warwick' as the CBD or a region extending tens of kilometres around.

17-01-2000. A series of thunderstorms developed on the Darling Downs causing power blackouts. Warwick reported gusts to 83 km/h and small hail was observed.

12-12-2000. Large cells on the southern border ranges, with a report of 90-100 km/hr wind gusts and hail 3-4cm diametre at the intersection of the New England and Cunningham Highways - Near Warwick?

1-9=2001 Golf ball size hail was reported 13 kilometres north of Warwick and 1cm hail was reported from Deuchar, 20 kilometres north of Warwick with a ground covering of about 3cm.

11-11-2001 Some building damage occurred near Warwick in the southeast Darling Downs.

16-3-2003 Hail 2.5cm in diameter was observed near Warwick.

26-10-2003 At Warwick hail to 5cm with a 100km/h wind gust and some flash flooding occurred.

16-12-2003 On the 16th a severe storm occurred at Warwick. Wind gusts brought down trees, and hail was also reported.

24-1-2004 Other areas to be affected by storms include Warwick where golf ball sized hail was reported from a storm in the area

28-1-2004 Warwick 91 km/h

03-01-2006. A 93km/h wind gust was recorded in a thunderstorm at Warwick. Trees and power lines were bought down, sheds demolished and roofs ripped off. Much damage occurred as a result of flying debris. A tornado was also sighted to the east of Warwick.

27-9-2006 Thunderstorms in the early evening produced marble to golf ball sized hail at Warwick.

13-1-2007 Widespread severe thunderstorms in the central west and southeast produced a storm at Warwick with 4cm hail reported.


I also seem to recall a decent hailstorm hitting Warwick last year or the year before?


Edited by Nature's Fury (03/01/2018 17:57)

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#1447154 - 03/01/2018 17:59 Re: Ideal set-ups for severe storms to hit your location [Re: Brett Guy]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 2034
Loc: Brisbane Western Suburbs
Originally Posted By: Brett Guy
As a Cairns resident I would say the ideal set up would be to move to SE QLD. We have had One storm this year. 2 months ago. It lasted all night which was exceptional as they normally last half an hour but that was it. one all night rumbler. No strong winds or excessive rain or hail or anything else. Generally the tablelands is good(not this year) but the topography means 90% of storms that do move east die out as soon as they fall of the ranges west of cairns. Bad topography combined with an air mass that is way to stable through the upper levels means we miss out unfortunately. It is not something I would have imagined before moving here.
And I also have to note that the term 'severe' is relative in my experience. The few systems I have seen labled as 'severe' up here would barely raise an eyebrow in SE QLD.


Must be pretty slow up there. You don't get proper storms, wet seasons are hit-and-miss, cylones even more so. Then you have the months of heat and humidity.

SE QLD/NE NSW is the thunderstorm capital of Australia (although they might change in future decades...). As a storm enthusiast I'm very lucky to be here.

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#1447159 - 03/01/2018 18:27 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Brett Guy Offline
Meteorological Motor Mouth

Registered: 05/10/2010
Posts: 5019
Loc: Bently Park, Cairns
Originally Posted By: Nature's Fury
Originally Posted By: Brett Guy
As a Cairns resident I would say the ideal set up would be to move to SE QLD. We have had One storm this year. 2 months ago. It lasted all night which was exceptional as they normally last half an hour but that was it. one all night rumbler. No strong winds or excessive rain or hail or anything else. Generally the tablelands is good(not this year) but the topography means 90% of storms that do move east die out as soon as they fall of the ranges west of cairns. Bad topography combined with an air mass that is way to stable through the upper levels means we miss out unfortunately. It is not something I would have imagined before moving here.
And I also have to note that the term 'severe' is relative in my experience. The few systems I have seen labled as 'severe' up here would barely raise an eyebrow in SE QLD.


Must be pretty slow up there. You don't get proper storms, wet seasons are hit-and-miss, cylones even more so. Then you have the months of heat and humidity.

SE QLD/NE NSW is the thunderstorm capital of Australia (although they might change in future decades...). As a storm enthusiast I'm very lucky to be here.


Not the most exiting place for weather but it does have some good points. We can enjoy 200mm of rain without any fear of major(widespread at least) flooding. Cyclones are(or at least can be) fun providing they are not too big and if they are they still qualify as exiting for me. Gotta look on the bright side

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#1447161 - 03/01/2018 18:40 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Warwick Eye2Sky Offline
Weather Freak

Registered: 31/08/2010
Posts: 854
Loc: Warwick, QLD
Wow Natures Fury, thanks for that! Great site! I am up to the year 1938. Yes, Warwick is mentioned quite a bit, especially in the mid 1800's.
You are absolutely right about the infancy stage. I actually thought however that the valley and surrounding hills prohibited storms from holding together. I am glad to hear that this town is actually in a favourable area.
I have friends tell me that back in the 70's and 80's Warwick itself would get hit quite frequently from storms approaching from the SW.
It appears that the colder periods (decades) tend to deliver the storms. Maybe has something to do with the colder upper atmosphere. Maybe with the Grand Solar Minimum on our doorstep, the storms will return? That is another topic for discussion. Thank again!
Cheers,
Michael
_________________________
Michael - your eyes to the west.

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#1447226 - 04/01/2018 10:13 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Coxy Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1048
Loc: Jindalee, QLD
Originally Posted By: Nature's Fury


1990s - There were a number of hailstorms that hit this area. There was a nasty one that delivered golf-ball sized hail that came from the SW sometime in the mid-late 1990s. According to Coxy there were a few of these in the 90s. I can also remember a hailstorm hitting during the Easter period in the late 90s but fuzzy beyond that.


Yeah there was a Christmas Eve storm in 1989 or 1990 that annihilated us in Kenmore. Brought down trees in our back yard (And I mean a big Silky Oak) and we were without power until late on Christmas Day. Can't recall if there was hail, but the wind was intense.

There was one other occasion in summer 1993 or so where I was caught at the cricket nets with my mate when a hail storm rolled through. My dad had to come and collect us and he was pissed off haha.

I couldn't tell you what direction the storms came from though.

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#1447228 - 04/01/2018 10:23 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Chris Stumer Offline
Weatherzone Addict

Registered: 28/01/2010
Posts: 1749
Loc: Kingaroy
A surface low to the west to give the atmosphere it's twist and an upper trough to the east to give instability.

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#1447232 - 04/01/2018 11:09 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
ozone doug Offline
Weatherzone Addict

Registered: 06/11/2006
Posts: 1736
Loc: Roma SW QLD Eye to the West...
I remember in the 1970s at Redcliffe not hearing to much damage ,But very violent thunderstorms as in lots of very close and large number of ground strikes then decreasing in number in the 80s and 90s .But more damage. In the 1970s the strikes were unbelievable house rockers like bombs going off.And about 3 streets away we had a substation that was always hit ,In the 1990s it was dug up and found Fulgurites there .I was told by a neibour who was working there went up and had a look about 1ft long the one i saw ,looked more like molten sandblast metal or like what you get on a cutoff saw the metal and grit together rather than glass that some look like.
_________________________
Cheers Doug. 491 Doug/ uhf ch40 When severe weather
BOM Stormspotter G0388 Roma S W Queensland Formerly Redcliffe.

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#1447249 - 04/01/2018 13:18 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
TWEEDSTORM Offline
Weather Freak

Registered: 08/01/2012
Posts: 699
Loc: Tweed Heads NSW
Think the 70'were very productive up and down the east coast because when I lived in Sydney during that period there were regular violent spring and summer storms. I have to say since I been living up here the trophy goes to Beaudesert for reliability and severity of storms.Start your day down Rathdowney and follow the storm through Beaudesert and beyond.Its a great day out for thrillseakers.

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#1447259 - 04/01/2018 14:10 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
BIG T Offline
Weatherzone Addict

Registered: 24/01/2012
Posts: 1037
Loc: Albany Creek , QLD
yeah , im not as technical as some but the perfect setup to cop a pasting here would be a southerly pushing up through the gold cst mid arvo , a triple point around boonah or even closer , as i dont think they need to be that far away when they really get started. Add a sort of a mix of a decent moist seabreeze and not as moist northerly to let the storm inhale some mixed moist air & then watch it bomb. And dont forget to shut the windows on the southern side of the house.

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#1447267 - 04/01/2018 16:07 Re: Ideal set-ups for severe storms to hit your location [Re: Coxy]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 2034
Loc: Brisbane Western Suburbs
Originally Posted By: Coxy
Originally Posted By: Nature's Fury


1990s - There were a number of hailstorms that hit this area. There was a nasty one that delivered golf-ball sized hail that came from the SW sometime in the mid-late 1990s. According to Coxy there were a few of these in the 90s. I can also remember a hailstorm hitting during the Easter period in the late 90s but fuzzy beyond that.


Yeah there was a Christmas Eve storm in 1989 or 1990 that annihilated us in Kenmore. Brought down trees in our back yard (And I mean a big Silky Oak) and we were without power until late on Christmas Day. Can't recall if there was hail, but the wind was intense.


That was this one:

http://www.bsch.com.au/reports/24_12_89.shtml

One of the 'historic' storms to hit SEQ. Came off a southerly change, dropped multiple tornadoes, caused huge damage.

I was wondering if that hit this area too, clearly it did if it was bad out at Kenmore as well.

One of the admins on South Brisbane Storms posted a picture they had (from the northern suburbs) and it looked nasty. There's also a picture on the link I posted.

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#1447271 - 04/01/2018 16:49 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
jessie Offline
Weather Freak

Registered: 14/10/2011
Posts: 88
Loc: Mt forbes
Awesome nf that picture says 1000 words.

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#1447278 - 04/01/2018 17:49 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Chris Stumer Offline
Weatherzone Addict

Registered: 28/01/2010
Posts: 1749
Loc: Kingaroy
I remember staying at my Grandma's place in Moorooka during the mid 90s and a monster hailstorm came through, the hailstones were bigger than cricket balls. A bloke had a set up on his car in the carpark to catch the hailstones and/or protect his car at the height of the storm.

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#1447288 - 04/01/2018 18:39 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 1739
Loc: Wollongong, NSW, Aus
Driving somewhere that actually gets storms frown

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#1447289 - 04/01/2018 18:43 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 1739
Loc: Wollongong, NSW, Aus
Originally Posted By: Nature's Fury
SE QLD/NE NSW is the thunderstorm capital of Australia (although they might change in future decades...). As a storm enthusiast I'm very lucky to be here.


Nothing like a bit of hyperbole....but facts are Darwin and Top End gets nearly 3x the number of storms you guys get. Now, severity wise, there may be an argument, but purely numbers wise they kill you.

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#1447293 - 04/01/2018 18:52 Re: Ideal set-ups for severe storms to hit your location [Re: Kino]
Nature's Fury Offline
Weatherzone Addict

Registered: 29/11/2009
Posts: 2034
Loc: Brisbane Western Suburbs
Originally Posted By: Kino
Originally Posted By: Nature's Fury
SE QLD/NE NSW is the thunderstorm capital of Australia (although they might change in future decades...). As a storm enthusiast I'm very lucky to be here.


Nothing like a bit of hyperbole....but facts are Darwin and Top End gets nearly 3x the number of storms you guys get. Now, severity wise, there may be an argument, but purely numbers wise they kill you.


I meant in terms of severe thunderstorms.

What are southerly changes like for you down there? Can they also bring serious action like up here?


Edited by Nature's Fury (04/01/2018 18:54)

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#1447320 - 04/01/2018 22:46 Re: Ideal set-ups for severe storms to hit your location [Re: Nature's Fury]
Steve O Offline
Weatherzone Addict

Registered: 02/03/2011
Posts: 3026
Loc: Beenleigh, QLD
So many variables to come together for the perfect storm. SEQ can produce severe weather any time of the year. My perfect storm would have extremely steep lapse rates and strong shear but personally I don't like the S'ly change as it usually pushes activity NW of my local area...i know im greedy.


Edited by Steve O (04/01/2018 22:53)

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