2006-12-09 Wx Discussion and Forecast
Discussion for Saturday, December 09, 2006
IOP in progress. Radar-based rain estimate for the period ending 1200UTC today shows about a half inch fell before sunrise, pretty well in line with expectations.
Today’s precipitation in the ARB looks continuous but light, around .25 inch in the morning, another .25 inch in the afternoon. It starts to pick up after sundown, another .5 inch before midnight. It’s the 6-hr period before dawn tomorrow where the heaviest rates are expected to occur, probably over an inch. This coincides with the coldest air of the event, a 12-18 hr stretch where the 1000-500 mb thickness appears to hover around 540 dkm, resulting in a snow line around 4500-5000 ft.
Rain rates back off a little Sunday morning, and then there’s one more shot of about .75 inch Sunday afternoon, tapering off before midnight. Thus endeth IOP #1.
Onshore flow continues to the north of the area of interest through Monday and even Tuesday but there’s little chance that action slips far enough south to impact any HMT-related decisions. That band of moisture could end up making a couple 6-hr periods late Tuesday with .25-.5 inch, but big deal.
We’ve mentioned the prospects for an IOP late next week, but those chances have diminished in recent model runs.
Paul Schultz
ESRL/GSD/FAB