# Saturday, December 8, 2007
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NRL GOES Composite Visible/IR Satellite Image December 8, 2007 1:30 p.m. PST Click!
NRL GOES Composite Visible/IR Satellite Image
December 8, 2007 1:30 p.m. PST

Model performance hasn't been the best this Autumn. Sometimes this has worked in our favor, and sometimes not. The elements of Thursday night's system came together a little differently than projected and it wasn't as strong as expected.

Given the flash flood and debris flow potential in recently burned areas, the amount of rain was probably about as much as could be handled without causing too many problems. Downtown Los Angeles (CQT) recorded 0.41 inch of rain, bringing the water year total (since July 1) up to 2.44 inches -- still 0.16 inch above normal for the date. Last year at this time only 0.50 inch had been recorded.

Rainfall totals around the Los Angeles area generally ranged from about 0.25 to 1.00 inch, with as much as 1.0 to 2.0 inches (or more) recorded in some foothill and mountain locations. Here's a copy of a NWS Information Statement listing some rainfall totals for the storm.

An NRL GOES composite visible/IR satellite image from 1:30 p.m. PST this afternoon shows a strong vorticity max and upper low center near Pt. Conception, embedded in very strong north-northwesterly flow associated with a digging trough. The upper low is somewhat moisture starved, but very energetic. GOES soundings around the base of the trough indicates precipitable water values on the order of 0.50 to 0.75 inch. Radar shows some convective shower activity associated with the disturbance.

The 18z models project that the low will continue to dive south down the coast before moving onshore in northern Baja Mexico. Both the NAM and GFS generate about 0.1 inch at Los Angeles over the next 24 hours, with somewhat more to the south -- about 0.4 inch at San Diego according to the NAM. Because of the convective nature of the system, precipitation may be widely scattered and variable. Some areas may record no rain and others significantly more (or less) than the projected values. Here's the Day 1-2 QPF forecast from the HPC.

Today's (un-interpreted) NWS 6-10 and 8-14 day outlooks call for above normal precipitation in Southern California. In support of this notion, the 12z run of the ECMWF develops a full latitude trough around December 17, and the 18z GFS brings a strong system into California around December 19. A lot could change between now and then, but we'll see!

More information concerning Southern California weather can be found using our WEATHER LINKS page.