Some cloud scenes from yesterday; a forecast map gone awry?

0.07 inches here in Sutherland Heights yesterday afternoon. Much more SW-NW of us, as the photos below show.

DSC_7961 DSC_7955 DSC_7945 DSC_7924 DSC_7909

A predicted super hurricane?

I now direct your attention to the forecast maps below, produced by the WRF-GFS model last evening’s global data, courtesy of IPS MeteoStar, the usual.  The aforementioned extremely strong hurricane foretold in the models 24 hours ago, has acheived in this latest run, mythical strength, possibly a Category 6 or 7 (which don’t yet exist).

We presume the model went berserk, so its kind of fun to imagine how intense, how low the pressure in the center of such a goofy predicted hurricane could possibly be in the panels below.

First, the jaw-dropping -to-weather-nerds like the current writer, predicted height of 540 decameters height of the 500 millibar pressure level!  For the pressure of 500 millibars in the atmosphere to be reached at a level that LOW in warm tropical air means that the sea level pressure must be astoundingly LOW to begin with.  In warm air, the pressure doesn’t change as rapidly going up as it does in dense cold air.

I don’t believe, in viewing many weather maps with hurricanes that a height that low has ever occurred at 500 millibars.  Thus, the pressure at sea level, for whatever reason, must be incredible in this predicted hurricane SW of Cabo.  Surf will be up!

The record measured low pressure at sea level is 870 mb in one of the super typhoons (Typhoon Tip) in the Pacific some years ago where winds were estimated at about 200 mph.  It is thought that recent devastating Super Typhoon Haiyan, 2013, had a lower pressure, 858 mb, or the equivalent of the density of air at 5,000 feet elevation was thought to have occurred at sea level!

Valid at 5 AM AST, Sunday, July 19th.
The heights of the 500 millibar pressure level predicted for 5 AM AST, Sunday, July 19th.  The center of the hurricane SW of Baja  is shown to be 5400 meters (540 “decameters”).
2015071000_WST_GFS_SFC_SLP_THK_PRECIP_WINDS_228
Valid at the time of the above map. The surface pressure lines are too packed to display, but the center pressure would certainly be less than 900 millibars, and in such a tight center, winds, maybe 200-300 mph, tornado-like. Kidding only slightly.

OK, enough fun with a crazy model prediction, though this hurricane will be extremely strong, and the models are still bringing its pathetic, but wet, remnant into California a couple of days later.  Many July rain records, though they are not much to begin with, will be broken if this remnant does make it to Cal.

What we really hope for is some aircraft reconnaissance reports during the life of this strong hurricane instead of satellite-derived estimates of strength (though the latter are quite good).

We still look quite wet during this period, too.

 

The End.

By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.