tag:blogger.com,1999:blog-7478606652950905956.post2892989203531339338..comments2024-03-28T03:08:44.068-07:00Comments on Cliff Mass Weather Blog: Sunday AM UpdateCliff Mass Weather Bloghttp://www.blogger.com/profile/13948649423540350788noreply@blogger.comBlogger37125tag:blogger.com,1999:blog-7478606652950905956.post-51899742220332970082010-11-21T19:35:38.660-08:002010-11-21T19:35:38.660-08:00Third comment on this entry ... about the (possibl...Third comment on this entry ... about the (possible) artifacts in Rainwatch 24 hour precip accumulation.<br /><br />KATX radar switched to "clear air mode" at 1638 and has been running in that mode until at least 1935 (as I type this). I suspect it will be like this for the rest of the night. The maximum return from precip is +28 dBz or less i.e. not much precip especially for wet snow. <br /><br />There is still mostly+16dBz precip (with some +20dBz showers) over the South Sound (Seattle and further south).<br /><br />The "artifacts" are growing an seem to be at a constant radius from KATX and have continued to increase in intensity (as Rainwatch sums them up). You can see this if you run the 24 pcp as a "movie".<br /><br />Looking at the live radar from UW (or Wund) I don't see anything that matches up with that intense band hence my thinking it's not real.Kevin Purcellhttps://www.blogger.com/profile/18157202870194603923noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-44498135726333253562010-11-21T18:00:49.296-08:002010-11-21T18:00:49.296-08:00Before people get too worked up about "the sn...Before people get too worked up about "the snow" and "the failure of the forecast" take a look at Rainwatch <br /><br /><a href="http://www.atmos.washington.edu/SPU/?product=pcp24c&tz=utc&section=prod&domain=d0&zoom=Z1&NEXRAD=ATX&start=200901010000&stnid=KSEA&end=2009012312359&type=obs" rel="nofollow">Click for Rainwatch 24 hour rain accumulation in Western WA</a><br /><br /><a href="http://www.atmos.washington.edu/SPU/?product=pcp24c&tz=utc&section=prod&domain=d0&zoom=Z2&NEXRAD=ATX&start=200901010000&stnid=KSEA&end=2009012312359&type=obs" rel="nofollow">Click for Rainwatch 24 hour rain accumulation in the Puget Sound</a><br /><br />Over most of the region (and especially over the the Metro area) the 24 hour accumulation is less than 0.1". There are some areas above 0.1" in the South Sound. There are also a handful of hotspots (and I'm not sure if they're not artifacts) north of Orcas Island and over Mt Baker(?) with with red intensities (wet snow? intense snow showers?). Wet snow has a larger radar cross section than rain drops so even these plots might over-estimate the total precip. <br /><br />Remember an 1" is less than 0.1" rain so a little rain as snow goes a long way.<br /><br />Looking at the precip rate you can see the rate (aside from a few heavier embedded showers) over most of the Puget Sound lowlands in 15dBz or less with showers < 25dBz. If this were rain you wouldn't notice it (a light drizzle).<br /><br />The precip band is SE to NW across the South Sound just clipping the south of Seattle. It isn't moving east or north. In the IR sat it doesn't have very high cloud tops (unlike the clouds further to the south). That looks rather like what the WRF-GFS prognostication said but a fraction wetter (or wetter later)<br /><br />The air temp is still above freezing but I presume the snow level is now at the surface for most of the metro area. But that snow that's hitting the surface is wet and soon melts. There has been no snow accumulating on Capitol Hill at 300 feet. The accumulation is the issue not that we have a bit of frozen precip that makes it to the surface (where it finishes melting).Kevin Purcellhttps://www.blogger.com/profile/18157202870194603923noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-86076060815928948712010-11-21T15:38:46.327-08:002010-11-21T15:38:46.327-08:00The 12Z Sun 21 Nov WRF-GFS run is showing the shor...The 12Z Sun 21 Nov WRF-GFS run is showing the short wave trough moving with uplift this evening and tonight over Puget Sound (and the rest of Western WA).<br /><br /><a href="http://www.atmos.washington.edu/mm5rt/data/2010112112/images_d2/500vor.15.0000.gif" rel="nofollow">http://www.atmos.washington.edu/mm5rt/data/2010112112/images_d2/500vor.15.0000.gif</a><br /><br />More interestingly the 12Z Sun 21 Nov WRF-GFS it now has a closed upper level low sweeping over Western WA on Monday. So from about 7pm Sun through 7am Tues there is vorticity (and uplife) aloft first from the trough then from the low.<br /><br /><a href="http://www.atmos.washington.edu/mm5rt/data/2010112112/images_d2/500vor.36.0000.gif" rel="nofollow">http://www.atmos.washington.edu/mm5rt/data/2010112112/images_d2/500vor.36.0000.gif</a><br /><br />This looks similar to, though less intense than, the NAM model prognostication n the previous "Uncertainty" blog entry.<br /><br />But ... is there any water to precip with that uplift?<br /><br />The WRF-GFS snow prediction keeps the metro area clear of snow. The models precip will fall as rain from 10am to 4pm then dry up (that's what we see now ... wet snow/rain). And that's it. No more precip this evening or tonight or Monday in the Puget Sound.<br /><br />The precip is trailing off on Capitol Hill at 3:30pm.<br /><br />What do the NWS forecasters know that the mesoscale models aren't getting? Is the model right or do the forecasters have some extra skill?<br /><br />The next AFD should be interesting. It's not up as a type this.Kevin Purcellhttps://www.blogger.com/profile/18157202870194603923noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-25506032712477361062010-11-21T15:20:31.680-08:002010-11-21T15:20:31.680-08:00Dumpin pretty good here in Enumclaw. Have about 2...Dumpin pretty good here in Enumclaw. Have about 2 inches so far in town......keep it comin!!!!paintloverhttps://www.blogger.com/profile/02163478974713575981noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-12735024091838531242010-11-21T15:02:55.199-08:002010-11-21T15:02:55.199-08:00Just over 2 inches in Eatonville...started about 1...Just over 2 inches in Eatonville...started about 10:00 am. I'm guessing school will be on a 2-hour delay or closed all together since they are calling for more snow and wind tomorrow.windloverhttps://www.blogger.com/profile/06944033579068806230noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-39692083675493058532010-11-21T14:49:04.886-08:002010-11-21T14:49:04.886-08:00The temp is falling in Olympia and so is the snow....The temp is falling in Olympia and so is the snow. It is sticking now on the grass. I just put on the new Pink Martini Christmas CD and I'm going to have an eggnog latte and enjoy the scene.larchitechhttps://www.blogger.com/profile/02405453993339905510noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-26304654967720639372010-11-21T14:24:40.835-08:002010-11-21T14:24:40.835-08:00Snowing here on the UW campus, hard at times. Not ...Snowing here on the UW campus, hard at times. Not much is sticking, but if it keeps it up, who knows?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-9200404494660138202010-11-21T14:19:43.909-08:002010-11-21T14:19:43.909-08:00It's been snowing steadily in Aberdeen since 1...It's been snowing steadily in Aberdeen since 1030 am, and accumulating since noonish...a couple inches, I'd say! Keep it coming!M'sFanhttps://www.blogger.com/profile/14971248526626776108noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-76716169266857996642010-11-21T14:19:16.577-08:002010-11-21T14:19:16.577-08:00Cliff,
Just wanted to reinforce that you were rig...Cliff,<br /><br />Just wanted to reinforce that you were right in your blogs this weekend. The models and the snow charts you posted were right on. <br /><br />Simply amazing the progress being made. Thanks for all the updates too!smokejumperhttps://www.blogger.com/profile/05358322512081660205noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-35596049324464637432010-11-21T14:18:46.167-08:002010-11-21T14:18:46.167-08:00It's still snowing lightly here in Ballard at ...It's still snowing lightly here in Ballard at 2:15pm but it is not sticking. Very pretty though. Once again wishing I was closer to the foothills!Urbancowgrrlhttps://www.blogger.com/profile/15860022294549771879noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-39138158926518783432010-11-21T14:10:52.896-08:002010-11-21T14:10:52.896-08:00According to the radar the snow is coming back fro...According to the radar the snow is coming back from the southwest, moving northeast at a decent pace. Some places are getting a rain/snow mix but it looks like most are getting snow. Now it just depends on what the temperatures do this afternoon.Scott K.https://www.blogger.com/profile/09543174609187989825noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-46581527080948676542010-11-21T14:03:41.393-08:002010-11-21T14:03:41.393-08:00We woke up to a dusting of snow in Olympia that so...We woke up to a dusting of snow in Olympia that soon melted. It's been snowing here now since before noon but so far it isn't sticking.larchitechhttps://www.blogger.com/profile/02405453993339905510noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-69153069972304266262010-11-21T13:25:41.803-08:002010-11-21T13:25:41.803-08:00Light-to-moderate snow here in Tacoma.Light-to-moderate snow here in Tacoma.CAhttps://www.blogger.com/profile/16444051998587029087noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-84183730060026921732010-11-21T13:23:23.351-08:002010-11-21T13:23:23.351-08:00Not a single flake to be found in Mount Vernon are...Not a single flake to be found in Mount Vernon area. Sigh...C&Ahttps://www.blogger.com/profile/01153526280421118681noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-21289336177277573462010-11-21T13:07:24.856-08:002010-11-21T13:07:24.856-08:00This is just my gut feeling, no science, but I'...This is just my gut feeling, no science, but I'd say the models are wrong. <br /><br />Of course, part of my gut feeling stems from the fact that this fall when forecasters predict rain, it was clear and visa versa. <br /><br />The snow is coming down in buckets in Sammamish. The clouds are doing an awesome job of dropping the moisture they weren't supposed to have. Thankfully, it's warm enough that it's only collecting on the trees so far.<br /><br />I think in this part of the country where people aren't used to driving in snow, it's more responsible to err on the side of over-predicting snow than on underpredicting. When you underpredict, people who really shouldn't go out, do go out, and we have a meess.Teresahttps://www.blogger.com/profile/09704607178106828945noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-44395055988030027142010-11-21T13:01:49.514-08:002010-11-21T13:01:49.514-08:00Cliff- It seems as if the models always under gues...Cliff- It seems as if the models always under guess the amount of snow with an arctic air mass.<br /><br />Lots of light snow around and the next much bigger wave seems to be moving onshore now.<br /><br />Im betting for snow in Seattle on monday.Michael Snyderhttps://www.blogger.com/profile/06230219537755848399noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-61518286154895869852010-11-21T12:51:13.699-08:002010-11-21T12:51:13.699-08:00Been snowing in Aberdeen for about an hour and a h...Been snowing in Aberdeen for about an hour and a half, with about an inch and a half accumulation. Will it melt before night falls?Anonymoushttps://www.blogger.com/profile/16734007064893931861noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-79770196710789444472010-11-21T12:27:11.477-08:002010-11-21T12:27:11.477-08:00Spoke too soon. Ballard snow is gone. You're r...Spoke too soon. Ballard snow is gone. You're right again. Damn. I want CHAOS!S I G N A L I U Shttps://www.blogger.com/profile/12608491324607623354noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-955655309771009252010-11-21T12:13:13.248-08:002010-11-21T12:13:13.248-08:00Lake Stevens this morning woke up to a light dusti...Lake Stevens this morning woke up to a light dusting, it started snowing again for a couple hours, stuck on the ground for a bit then warmed up. Now it's just light snowing, but the snow on the ground is gone.<br /><br />Cliff, I know you said it's suppose to dry out tonight/tomorrow, but the 12pm Winter Weather Advisory(just updated now) from National Weather Service calls for 1 to 2 inches of snow in the seattle area, especially north and east of seattle. Yet, everywhere else I read says the snow is only going to be south, olympia, orgeon, etc.<br /><br />Why does the National Weather Service winter advisory differ so much from all of the other forecasts so far?Scott K.https://www.blogger.com/profile/09543174609187989825noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-83807029807830478822010-11-21T12:12:25.420-08:002010-11-21T12:12:25.420-08:00Snowing heavily in BryantSnowing heavily in BryantMichaelhttps://www.blogger.com/profile/03592060363558323782noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-41835129014540222462010-11-21T11:59:22.395-08:002010-11-21T11:59:22.395-08:00Started snowing at noon on Capitol Hill at about 3...Started snowing at noon on Capitol Hill at about 300 feet.Kevin Purcellhttps://www.blogger.com/profile/18157202870194603923noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-50578892661107224182010-11-21T11:54:35.226-08:002010-11-21T11:54:35.226-08:00So, Cliff? That's.. what. Three blogs wrong no...So, Cliff? That's.. what. Three blogs wrong now? One last week where you stated: "Forget lowland snow this weekend." Two: "Saturday and Sunday are going to be pretty dull around here." Three: "Forget most of western washington for snow." Four: "My conclusion, if the models are correct, the central Puget Sound Region, including Seattle, will get little if any snow."<br /><br />Three strikes your out at the ol' baaall game!Unknownhttps://www.blogger.com/profile/02555472133079188968noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-87035933349992767142010-11-21T11:54:19.356-08:002010-11-21T11:54:19.356-08:00Big, beautiful flakes in Ballard!Big, beautiful flakes in Ballard!S I G N A L I U Shttps://www.blogger.com/profile/12608491324607623354noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-41216384537299908712010-11-21T11:44:28.762-08:002010-11-21T11:44:28.762-08:00Well, I don't call this snow exactly (200 foot...Well, I don't call this snow exactly (200 foot elevation near Woodland Park) but a few fat flakes are falling and my daughter is jazzed. NWS seems to think there could be some snow, so???<br /><br />I am a snow fanatic so I hope so!Donna & Chrishttps://www.blogger.com/profile/04288137170747823068noreply@blogger.comtag:blogger.com,1999:blog-7478606652950905956.post-22646708928632632982010-11-21T11:41:21.788-08:002010-11-21T11:41:21.788-08:00Snowing very lightly on the north side of Queen An...Snowing very lightly on the north side of Queen Anne Hill.MBeebehttps://www.blogger.com/profile/06989291623192829581noreply@blogger.com