Professor Adam Monahan delivered his final lecture in Atmospheric Science 340 yesterday. On the way into Victoria for classes I observed the first significant cumulus development, and felt the convective potential from the parking lot on campus.
In his initial weather overview, referring to NAM chart six http://wxmaps.org/pix/nam.00hr.html, he noted the appearance of the pink contour line off the west coast for the first time since his lectures began in January, an example of the vernal switch to convective heating. This, he predicted could give rise to local thunderstorms and heavy local downpours, though the “pink” contour indicated a lower probability.
After returning to Sidney and Shoal Harbour Sanctuary, I noted that the cumulus had darkened into nimbus over the Cowichan valley ( Keuecen – the valley of sunshine and cumulus build-up) and the Malahat.
To backtrack : Just before I’d left for classes in mid-morning, the Buffleheads had aggregated and come to a momentary standstill, providing one of the first good counts in a while : 182. Evidently they were aware of “something in the offing”.
Then, as I began perusing the satellite images and weather charts, I was startled by a single loud clap of thunder over the Saanich Inlet (WSANEC – emerging people). Even the Buffleheads were alarmed, causing many juveniles to flush along with the Wigeons, and flying high, something they rarely do except when highly disturbed. The adults, long used to Cariboo and prairie lightning storms, remained alert. No-one has ever lectured them on the Convective Available Potential Energy (CAPE – joules/kg) behind such bangs.
A brief squall of large hail stones pelted the waters and Buffleheads, followed by an intense local downpour, the first of the season Sx’anel, referring to the Bullheads return. ( Bottom-feeders, like Buffleheads;-) Bullhead season is heralded by Thunder and high CAPE.
Professor Monahan concluded his superb lecture series with the sober statement that it was far harder to predict weather events than it was to predict climate, a fact echoed in the editorial of the New York Times:
“Even when there’s recognition of a gigantic problem – as with California’s aging levees – the cost of infrastructure improvements coupled with bureaucratic inertia means it’s always simpler to put off measures that might avert future calamities. And so it’s easier to take the gamble that the catastrophe won’t happen, the storms won’t roll in, the flood won’t come, even though ever more scientific evidence says it will.”