February Weather Discussion. Wild Winter Storms?

[Andrew]

Ed LOVES to hear himself talk. More times than not I skip through his jibberish. If you want to hear yourself talk Ed, carry around a tape recorder for crying out loud you half empty, half full of...well, you know.


Sorry you don't know enough to actually contribute.


Anyway, shouldn't it be I like to hear myself type?


Or do you sound out the words when you type?


















KIDDDING!!!!!!

oops...

Haha all this is really funny. Snow plus humor= good forums.

[ticka1]

when I say things like that people on the forum call me a tool and call for me to be banned.

No, it's because you said things like a winter weather advisory wouldn't verify for our northern counties and all snow would be well west and north of Houston, which is already in line to fail

I was discussing last night's 0Z GFS, which if it was correct, would indeed not verify for accumulating snow, especially on road surfaces. Did I mention I posted my hopes the 0Z GFS would be too warm?

The someone insists on babbling about where the 850 mb freezing line is, and insists that even with 0.10 inch 6 hour precip rates surface temps don't matter, it will all accumulate.


Oh, then I said a WWA could verify for temps near freezing / damp roads after precip ends up towards CLL and vicinity, again saying it was the GFS numbers and they can sometimes be too warm. I apologized for my mistake. Used a Latin term. I don't speak Latin. But "mea culpa" is a term almost any literate person understands. Presuming people are literate, well, mea culpa.

Then I think I hoped for a mesoband on my house.

Some people have poor reading comprehension, and some people are confident snow flurries will coat the ground at 39ºF as long as the 850 mb freezing line has passed. What can I do?


If I bother to stay up for the 0Z GFS, I will check 6 pm forecast and actual station temps and dewpoints at places upwind. Doesn't help with upper air, although model soundings can be compared to actual balloons. Ditto 0Z NAM. If the models are too warm or too moist on upstream temps/dewpoints, depressing model forecasts, like almost 40ºF with light snow, may not work out. Happiness could be on tap despite model gloom.

The other thing is meso-banding, which is hard to see if the models are in the ballpark, for an amateur like me. Mid/upper 30s temps aren't as big a buzz kill on snow accumulating if it is coming down hard. 2 inches an hour will do wonderful things, even if it is closer to 40º than freezing.

And guess what - no one can call ED a wishcaster - he might be called a half glass fullcaster....but if Ed didn't post I would never get to learn about all the interesting off-topic tidbits he throws out to us here at the weather forums. Ed I for one am glad you are here - yeah you make me mad sometimes - but sometimes that's a good thing...makes me learn something besides being a wishcaster. I have always been taught the mechanics of a good debate is a outstanding presentation of the differing view.

Were you on the debate team ED?

[Andrew]

NAM is about to start. Lets see if anything changes.

[wxman57]

With the last event, the dew points started out in the upper 20s, leaving room for the temp to fall to 31-32 as precip fell. That's why we had significant accumulations.

I don't believe that is true. The temperature at IAH never dropped below 32 degrees until after the snow was over (finally fell to freezing between 11 pm and midnight). Temperatures were in the mid 30s during the snow event. We had significant accumulations because the precip was heavy enough. Surface temperatures certainly didn't help anything (and rose even more after the snow was over before falling below freezing when the clouds moved away)

Tomorrow will be a very similar setup to Dec. 4th-5th of last year, but with the temperatures across Houston 2-3 degrees warmer. That could make all the difference. We really need to get some colder air advecting into Houston, colder than the models are currently indicating. I do hope that we see significant snow, as cold and wet without snow is just miserable.

I'm looking at the progged 18z GFS surface temps, and I am NOT saying they are right, but the model forecasts temperatures to be exactly where they were during the event last December, in the mid 30s.

We were monitoring the temperature at our office as snow fell in December. It was steady at 34 as the snow began, then it fell to 31 during the snow. Soon as the snow ended, it went back to 34 and the snow melted. Now it did hurt to have additional rain after the snow stopped. That prevented the snow from sticking around much.

As I've been saying, look upstream to the air that will be overhead tomorrow. That's up in NE TX and OK. Temps there aren't very cold. That 32 currently in OKC would translate to about 45F here in Houston when adiabatic heating from the lower elevation is taken into account (about a 13-14F rise from OKC to Houston). I'd like to see temps in the mid to upper teens in OK now.

So it's not just the temperature of the air is here now or projected to be here tomorrow afternoon, it's what is upstream and will be moving south into our area that concerns me. It just doesn't look cold enough for a big accumulating event.

[Andrew]

Nam looks colder so far.

[Mr. T]

We were monitoring the temperature at our office as snow fell in December. It was steady at 34 as the snow began, then it fell to 31 during the snow. Soon as the snow ended, it went back to 34 and the snow melted. Now it did hurt to have additional rain after the snow stopped. That prevented the snow from sticking around much.

Ah, ok. I cannot comment about what the temperatures were at your office, but the temperature at IAH was near 40 before the snow began and temps fell to the mid 30s thereafter. I do not remember any rain after the snow ended, nor did any reporting sites report rain after the snow began. I do remember some sleet mixed in with the snow for a little bit in the beginning.

As I've been saying, look upstream to the air that will be overhead tomorrow. That's up in NE TX and OK. Temps there aren't very cold. That 32 currently in OKC would translate to about 45F here in Houston when adiabatic heating from the lower elevation is taken into account (about a 13-14F rise from OKC to Houston). I'd like to see temps in the mid to upper teens in OK now.

So it's not just the temperature of the air is here now or projected to be here tomorrow afternoon, it's what is upstream and will be moving south into our area that concerns me. It just doesn't look cold enough for a big accumulating event.

But wouldn't local evaporative cooling effects take care of everything? It is pretty irrelevant what temperatures are in OKC once precip begins to fall....

Again, I don't think we want dewpoints in the 20s again. During the 04 snow event and 09 snow event, dewpoints up north were in the single digits and teens. This caused areas north of IH-10 to be too dry for significant snow, as very dry air began to advect into the region. All we got last time was a bunch of virga. This time, moisture profiles are more moist to the north of us, and again, I feel this is our advantage this time, especially for folks north of IH-10. I'm pretty sure if you go back and look at all of the siginificant snow events areas north of IH-10, they did not began with very dry dewpoints to the north. That is a sign that very dry air is about to advect into the area (virga producer!), and I don't think that is a good thing at all. If we can have dewpoints and temperatures stay in the 30s, I think this will keep the lower atmosphere more moist, and the snow will be able to reach the ground easier. Upper air temperatures and thicknesses are similar to the 09 event, except with a more moist lower profile!

[Mr. T]

I was discussing last night's 0Z GFS, which if it was correct, would indeed not verify for accumulating snow, especially on road surfaces. Did I mention I posted my hopes the 0Z GFS would be too warm?

The someone insists on babbling about where the 850 mb freezing line is, and insists that even with 0.10 inch 6 hour precip rates surface temps don't matter, it will all accumulate.


Oh, then I said a WWA could verify for temps near freezing / damp roads after precip ends up towards CLL and vicinity, again saying it was the GFS numbers and they can sometimes be too warm. I apologized for my mistake. Used a Latin term. I don't speak Latin. But "mea culpa" is a term almost any literate person understands. Presuming people are literate, well, mea culpa.

Then I think I hoped for a mesoband on my house.

Some people have poor reading comprehension, and some people are confident snow flurries will coat the ground at 39ºF as long as the 850 mb freezing line has passed. What can I do?


If I bother to stay up for the 0Z GFS, I will check 6 pm forecast and actual station temps and dewpoints at places upwind. Doesn't help with upper air, although model soundings can be compared to actual balloons. Ditto 0Z NAM. If the models are too warm or too moist on upstream temps/dewpoints, depressing model forecasts, like almost 40ºF with light snow, may not work out. Happiness could be on tap despite model gloom.

The other thing is meso-banding, which is hard to see if the models are in the ballpark, for an amateur like me. Mid/upper 30s temps aren't as big a buzz kill on snow accumulating if it is coming down hard. 2 inches an hour will do wonderful things, even if it is closer to 40º than freezing.

What you seem to fail to realize is that models are simply a "tool" to be used for forecasting. They are not the final say in anything. It is up to the forecaster to interpret the data and come up with their own forecast. All I ever see you do is post what the 2m temp will be at IAH at hour 36 without any analysis and reading it as fact. It's just annoying. It is shocking, I know, but models can be wrong.

[ticka1]

Watching.....way way out west

http://www.intellicast.com/National/Radar/Current.aspx

[Andrew]

NAM is defiantly colder:

[Mr. T]

NAM is defiantly colder:

I would hope so. It was way warmer than any other global model

I am eagerly awaiting Ed's analysis of the 0z NAM using Accuwx Pro Site graphics

[wxman57]

But wouldn't local evaporative cooling effects take care of everything? It is pretty irrelevant what temperatures are in OKC once precip begins to fall....

Again, I don't think we want dewpoints in the 20s again. During the 04 snow event and 09 snow event, dewpoints up north were in the single digits and teens. This caused areas north of IH-10 to be too dry for significant snow, as very dry air began to advect into the region. All we got last time was a bunch of virga. This time, moisture profiles are more moist to the north of us, and again, I feel this is our advantage this time, especially for folks north of IH-10. I'm pretty sure if you go back and look at all of the siginificant snow events areas north of IH-10, they did not began with very dry dewpoints to the north. That is a sign that very dry air is about to advect into the area (virga producer!), and I don't think that is a good thing at all. If we can have dewpoints and temperatures stay in the 30s, I think this will keep the lower atmosphere more moist, and the snow will be able to reach the ground easier. Upper air temperatures and thicknesses are similar to the 09 event, except with a more moist lower profile!

If the dew points are in the 33-34 range, then there is no room for evaporative cooling. The temp can only fall to the wetbulb temperature, which is above freezing. But if the dew point started out in the upper 20s, then as precip fell it would drop the surface temp below freezing. But there's a point of diminishing returns. Drop the dew points into the teens and it may be too dry for significant precip.

By the way, did you notice that the 00Z NAM keeps snow (accumulating snow) well north of Harris County? More precip than 18Z by far, but nowhere near Houston for accumulations.

[ticka1]

How many more model runs do we have before the actual event arrives?

[wxman57]

NAM is defiantly colder:

I would hope so. It was way warmer than any other global model

I am eagerly awaiting Ed's analysis of the 0z NAM using Accuwx Pro Site graphics

You can see some good charts here:
http://www.twisterdata.com/

Just click "NAM" on top and "Winter" in lower left frame then "Snow Depth". Navigate to the proper panel (32-36 hrs). Here's the 00Z snow map from the NAM:

http://www.twisterdata.com/data/models/ ... URFACE.png

Back to "24"...

[HouTXmetro]

But I want accumulating snow

[redneckweather]

Debate team and school newspaper...


You were wanting to go there sooo bad weren't ya Ed?

[wxman57]

How many more model runs do we have before the actual event arrives?

Every 6 hours. 00Z GFS/Euro, 6Z NAM/GFS, 12Z NAM/GFS/EURO and 18Z NAM/GFS/Euro

[Mr. T]

By the way, did you notice that the 00Z NAM keeps snow (accumulating snow) well north of Harris County? More precip than 18Z by far, but nowhere near Houston for accumulations.

Yes, but it is the only model doing that and the warmest by far. I'd rather go with the consensus of the other global models.

I have heard from several pro mets on Eastern US WX that NAM is usually terrible with snowfall accumulations, noting the poor performance with the last few storms to effect the NE. I wouldn't give it too much attention.

[wxman57]

NAM is colder, 2 meter temps a still a tad warm for accumulation in/near BW8 area, but trend is in right direction.

Look how dry that NAM sounding is, though.

[wxman57]

By the way, did you notice that the 00Z NAM keeps snow (accumulating snow) well north of Harris County? More precip than 18Z by far, but nowhere near Houston for accumulations.

Yes, but it is the only model doing that and the warmest by far. I'd rather go with the consensus of the other global models.

I have heard from several pro mets on Eastern US WX that NAM is usually terrible with snowfall accumulations, noting the poor performance with the last few storms to effect the NE. I wouldn't give it too much attention.

I agree, NAM is terrible. But if roles were reversed and the NAM was forecasting snow while the GFS wasn't what would you bet that many here would be the NAM's biggest fans?

[Andrew]

NAM is defiantly colder:

I would hope so. It was way warmer than any other global model

I am eagerly awaiting Ed's analysis of the 0z NAM using Accuwx Pro Site graphics

You can see some good charts here:
http://www.twisterdata.com/

Just click "NAM" on top and "Winter" in lower left frame then "Snow Depth". Navigate to the proper panel (32-36 hrs). Here's the 00Z snow map from the NAM:

http://www.twisterdata.com/data/models/ ... URFACE.png

Back to "24"...

that was the same with the last couple of runs though. The Nam has been the out-liner for snow. Hopefully it doesn't come true.