rdale
EF5
The status messages all morning pointed out the data ingest problems, very few RAOBs were in the 12Z NAM with about 50% for 12Z GFS. No issues with the afternoon stuff.
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11/20/07-11/22/07 FCST: NE/MN/IA/WI/IL (WINTER PRECIP)
- Thread starter Jeff Miller
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Robert Dewey
EF5
I guess we'll have to wait for the 00Z/TUE stuff then, but given that today's 00Z/MON run ingested just fine... and the trend between the 00Z/MON to the 06Z/MON was for a weaker system, I'm still not convinced. My gut is saying that there's only a slim chance that this storm will end up stronger than the GFS is showing on the 12Z and 18Z runs.
BTW... isn't the 18Z run just a regurgitation of the 12Z upper air stuff?rdale
EF5
Remember that UA is just one piece of the modeling puzzle... 18Z also had additional upper air / satellite / etc obs going in.
Robert Dewey
EF5
Regardless, the 00Z NAM isn't looking good. It's not as progressive as its previous runs, but is probably more of an indication that we'll see some sort of compromise between that and the less progressive GFS.
Joel Wright
EF5
Well, there's still some hope as the latest NAM is considerably less progressive than it was. The GEM is also in line with the new NAM. The earlier UKMET keeps the system deeper and further west as well.
The main vort max that will eventually brew this little beast is still just off the northwest coast, about to make landfall. I figured it'd be on shore by now, but I was wrong. I'm hoping that when this arrives on shore things may be tweaked a little more in our favor. By in our favor I mean a deeper, stronger, and more moisture laden system lol.
There's still some hope my friends! ;-)
Robert Dewey
EF5
Well, the models seem to be showing a less progressive solution. I notice the 12Z GFS is showing a closed isohypse at 850mb, and I suspect the NAM will follow suit in the 18Z or 00Z/WED run.
Also, the RGEM isn't looking too shabby, showing a stronger solution.
I'm liking the trends... We have 6 more model runs to go and if we can hold this trend, I'll be happy.rdale
EF5
That's a new one... Not predicting the weather - but predicting what the models will do?!? How do you determine that
Jeff Miller
EF5
Looking at the GFS total accumulated snowfall potentials, the track and strength of the system and warm ground temperature concerns, I'm fairly certain who does get snow out of this will get snow - but not in winter storm criteria. Certainly enough to induce the Christmas Spirit for those wishing to go out for shopping with the madness on Friday morning.
Along and north of a Davenport to Des Moines, IA line and points NE I think that 2 to 4 inches of snowfall total accumulation will be likely. In Michigan, GFS snowfall accumulation algorithms point to a little more - probably due to possibe lake enhancement and a stronger system at that time as Robert pointed out - in the order of a 3-5" total accumulation. This should be maximized in the Lansing, MI to the Detroit, MI locations with likely accumulations not exceeding 4" - I suspect 3" or possibly a little less again due to warmer ground conditions and the questions as if snowfall intensities will overcome melting for early season snows. I am discounting the ETA total snowfall solutions at this time - leaning toward the GFS - as the model is showing 1" or less of total snowfall accumulations. I do think that accumulations will be greater than an inch as I think this model is under-doing the intensity. I could be way wrong on this, but hey, might as well stick out my neck and make a call. If I'm right I'm right, if I'm wrong, I'm wrong.
Of course if the system surprises us with more intensity then these amounts would be likely stronger - but this is how I see it now. Suspect a wide swath of Winter Weather Advisories and Snow Advisories will be issued with this system, I don't see support for Winter Storm Watches unless models become more agressive the next couple of runs.Last edited by a moderator:
Robert Dewey
EF5
That's a new one... Not predicting the weather - but predicting what the models will do?!? How do you determine that
I suppose if you predict what the models are going to do, and the models predict what the weather is going to do, aren't you ultimately predicting what the weather is going to do?rdale
EF5
I'm on an inch, maybe two for the Lansing area, primarily on the grass. Can't see any way of getting something closer to 4" around here.
Brandon Sullivan
EF5
I agree with Rdale.. I personally think the main accums will be along and west of the IL river in IL.
Jeff Miller
EF5
Well, they don't pay me to forecast (thank goodness) so I am only sticking my neck out with my best efforts, as undereducated as they may be. Rdale is most likely to be right on with this, but hey, at least I'm making some attempts, as futile as my forecast is turning out to be.
At the very least, this thread wasn't totally for nothing and at least the early call of SOME winter precipitation worked.
Rdale, I hope you can get us some shots of the wintery weather, there's no snow to be found in the forecast where I'm at, save some scattered flurries.
Robert Dewey
EF5
The trend continues, so it looks like my "predicting what the models will do" wasn't too far off. The 18Z NAM actually brings down the -6C isotherm at 850mb during the heaviest precipitation, at least from LAN eastward. A quick 3 inches doesn't seem too unreasonable to me at this point, especially if the trend continues (oops - predicting forecast models again).rdale
EF5
The only useless forecast is from the people who chime in AFTER the event with "can't believe you said that, I knew this was going to happen"
New NAM is a little heavier with QPF, but the good snow growth region is pretty high up and there's not a lot of omega to go along with it. BL temps don't drop below freezing until after 9Z Thursday for Mid-Mich. I see snow falling, I just don't see it piling up...
Jeff Miller
EF5
First snow advisories going up for extreme southern wisconsin where 2 to 3 inches is the NWS prediction for that area... so I wasn't that far off regardless! Bit of a relief to me. Looking forward to seeing what other offices use for products.
Good to see the first midwest snow issuance of the year.Similar threads
