The term Low Bomb has been largely retired in the Northern Hemisphere, as it was an unofficial meteorological term in the first place and there are so many media sorts that have taken the opportunity to make severe weather into a profit center using such terms as leading lines on newspapers and newscasts that frighten folks into terror, only to have the forecast
bust or the storm to veer into another direction, thus diluting public concern and faith in the weather field in general, which in turn leads to people ignoring the warnings and dying in greater numbers than would have been necessary if even basic precautions had been taken by the dead (see Hurricane
Katrina, New Orleans
, Louisiana, USA). The surfers take to the ocean any time a hurricane
screams toward the East coast
of the US, especially if it parallels the shore at all. I am sure the same happens in Australia
Essentially, when a trough at about the 500 MB chart level passes over and causes a rapidly deepening low pressure system the low can go from a mild circulation of a couple hundred miles across into a massive cyclone (or hurricane, typhoon, willy willy, etc.) in hours, and if it shores up against a high pressure ridge down stream relative to the directional overall track of the storm's center of rotation the result is a massive storm with intensive pressure gradient within the storm interior
as well as especially the side closest to the high pressure ridge. This pressure gradient funnels wind
flow along lines of equal pressure (aka "isobars") to even greater speed than exists elsewhere around, or even potentially within, the storm interior
Yes, the Queen's Birthday event is a classic
example, and your area was definitely experiencing severe events
that day/night. If I recall
, there were something like 7 lost
recreational yachts, and I think some people died on one of the lost
vessels or in combination, at sea. 3 or 4 people, something in that range?
Hurricanes that strike the United States have done this on occasion, and someplace here I have the satellite
fax we received at NAS Jacksonville
, that showed the timeframe of Hurricane Andrew exploding as it passed over the Gulf Stream current
along Florida's coast. The damage to Florida
was devastating, and while part was due to low geography along the state and into the interior, part was due to inferior construction methods (since then, these construction problems have largely been addressed in local building codes, but we shall see how successfully one day), and the rest was due to the severe nature of the winds and especially tornadic activity within the bands and the eye wall itself.
I also have the last teletype forecast
that the USAF lead shift forecaster on duty sent out from the Homestead Air Force Base weather office. While his winds forecast was the stuff of meteorological legend in our military circles (200-250 knots on station is amazing for gust predictions for a shore station, but the base was in direct track with the actual storm center at landfall), it was the first and only time I have seen anyone forecast tornadoes in a specific location and time (he predicted "tornadoes all quads" in the immediate forecast, then "Closing and departing weather office, we're gone, Bourne out, see ya!").
When they returned from shelters, the weather office consisted only of a foundation; the structure itself, the air terminal, and nearby vehicles, along with the rest of the base, did not exist, other than a single
hangar left with a massive destroyed Galaxy or Constellation transport aircraft caved on inside, I don't think anything else on the base remained at all in the structural sense. In fairness, many structures on that base were wood framed structures, and the base was older than many. Still, I don't think the concrete stuff survived the scouring tornadoes either, though. The base is now the oval Homestead-Miami NASCAR racetrack!
Yep, the 500 MB chart overlaid on a surface chart does not often lie. Stronger winds upstream means deepening low, stronger winds downstream means the low will fill (become less intense), and a trough closing on the low (moves about twice the speed of the surface wind
field) leads to VERY intensive deepening (relative to strength of the trough itself and rapidity of approach makes the low blow up sooner or faster, and will be max effect when vertically stacked), or what the OP called the explosive cyclogenisis effect. Normally. Sometimes the winds can fool you, but it is damned
unusual that the 500 MB chart lies...