2006-12-29-HMT_forecast
Overall trends look similar to yesterday. A very deep (944mb) low is in the Gulf of Alaska this mrng, with a frontal band with waves to its south. Over the next few days, a succession of short wave troughs and associated surface lows will move NEwd from the Central and Western Pacific, affecting mainly the coastal region from the Alaska Panhandle down to NW Washington state. A weaker upper air feature that has been noted the past couple days is still forecast to meander slowly toward central and Northern CA, to the south of the main flow, and may give a little light pcpn in the HMT, mainly in the mountains, on 31 December 06 or early on 1 Jan 07. As noted yesterday, this system has little reflection at the surface, and is likely to be contaminated by dry air at lower levels during its opportunity to affect the HMT domain, and pcpn amounts are expected to be ~ 5mm or less at Blue Canyon.
The next pcpn opportunity comes as the main jet settles slowly southward. This will come during the 3-5 January period, according to present indications. It is too early to say with any confidence that this is a good IOP prospect, but as pointed out by K. Weickmann and E. Berry in today's telecon, this might well be the best prospect during the next 2 weeks or so. I think we should be alert to the possibility of an event similar to the one that happened 26 Dec, in which Blue Canyon picked up 1.4" liquid or so. Snow levels in this event seem unlikely to be above 6000' even at the start of the event.