What's "freezing at the surface" mean?

I quoted it from the National Weather Service:
www.wrh.noaa.gov/total_forecast/text_onl...waz519&county=wac053

I looked at their glossary:
Freeze
A freeze is when the surface air temperature is expected to be 32°F or below over a widespread area for a climatologically significant period of time. Use of the term is usually restricted to advective situations or to occasions when wind or other conditions prevent frost. "Killing" may be used during the growing season when the temperature is expected to be low enough for a sufficient duration to kill all but the hardiest herbaceous crops.
And I looked up surface, but basically i need this explained to me.

Freezing level at the surface when referring to a pass means just that, at the pass level through the gap. When we get these high pressure systems it usually traps cold air east of the mtns and this cold air will escape through the gaps (pass) keeping temps lower. This is what also leads to that waterfall effect of clouds spilling over the ridge when it is cloudy on the east, and sunny on the west.

I'm not an expert, but this is my best guess. I know for sure "freezing level at the surface" does not mean sea level.

Well the reason I say it is sea level is because when the freezing level is at pass level they usually say "freezing level at XXXX feet except at the surface in the passes". When it just says "freezing level at the surface" that time in the forecast is usually (per my observation) bracketed by very low freezing levels (like 1500 feet). The current wsdot west slopes cascade passes and foothills forecast has this. Temps for the sea level forecasts are at/near freezing for the same time period and temps at pass levels are quite a bit lower.

So by surface, they probably mean just that -- the surface everywhere in the forecast area (which can be very low, but not sea level since there is no sea level terrain in that forecast area).

This is from the NWS zone forecast which I read here .

THURSDAY NIGHT...PARTLY CLOUDY. FREEZING LEVEL 2000 FEET. EAST WIND IN THE PASSES TO 10 MPH.

FRIDAY...MOSTLY SUNNY. FREEZING LEVEL 1500 FEET. AFTERNOON PASS TEMPERATURES IN THE MID 20S TO LOWER 30S. EAST WIND IN THE PASSES TO 10 MPH.

FRIDAY NIGHT...MOSTLY CLEAR. FREEZING LEVEL AT THE SURFACE. WIND IN THE PASSES LIGHT.

SATURDAY AND SATURDAY NIGHT...PARTLY CLOUDY. FREEZING LEVEL AT THE SURFACE.

SUNDAY AND SUNDAY NIGHT...MOSTLY CLOUDY WITH A CHANCE OF SHOWERS. SNOW LEVEL AT THE SURFACE.

MONDAY...MOSTLY CLOUDY WITH A CHANCE OF SNOW. SNOW LEVEL 1500 FEET.

Friday night the forecast for Seattle is lows in the mid 20's to low 30's.  I take that to mean that the snow level at the surface is sea level.  Thursday and Monday are forecast to be warmer than Friday night through Sunday night, so it is not that the snow level would be moving up to pass level I don't think.

Friday night the forecast for Seattle is lows in the mid 20's to low 30's. I take that to mean that the snow level at the surface is sea level. Thursday and Monday are forecast to be warmer than Friday night through Sunday night, so it is not that the snow level would be moving up to pass level I don't think.

This forecast you posted above is for the pass, not Seattle.. If you look at the Seattle forecast it has no mention of freezing or snow. I don't think a Pass forecast would make any references to sea level, it wouldn't make sense IMO. Just a hunch on my part.....

[forecast for Seattle]

Friday: Mostly sunny, with a high near 43. North wind between 7 and 13 mph.

Friday Night: Partly cloudy, with a low around 28. North wind at 7 mph becoming west southwest.

Saturday: Mostly sunny, with a high near 42.

Saturday Night: Mostly cloudy, with a low around 29.

Sunday: Mostly cloudy, with a high near 43.

Sunday Night: Mostly cloudy, with a low around 33.

Ok
Freezing level at the surface as Volcanogirl points out in this coming fridays forcast is exactly or near sea level. look at the temps and freezing level of either day before or after .gonna be cold eh? Do you have Blue kick wax in your pack ? might be a good thing if you a little flat or road work to get to your turns.
The other terminology that is being referenced is or goes something like
"Snow level 5000' except at the surface in the Passes" along with" East wind in the Passes ---  mph "
Now that is a very special forcast (with secret codewords for skiers!)and as Jack L rightly points out Cold air is being sucked out of Eastern Washington by low pressure on the West side. Whats' special about it ? More often than not most skiers see the 5000' or say 6000' snow level and assume that it's raining in the passes. I see it and I'm going skiing in the passes !