December Weather Discussion. Will We See Rain?

[srainhoutx]

There has been discussions from the HPC and others concerning the 00Z Canadian, so I thought I'd post the charts...

[TexasMetBlake]

The weather service confirms that there was sleet in the Houston area this morning (mainly northern areas).

[TexasMetBlake]

Well, the 12z is rolling right now. Perhaps Mr. T can show us a TOGGLE between the 6z and 12z. It's out to 96 hrs...

[extremeweatherguy]

There has been discussions from the HPC and others concerning the 00Z Canadian, so I thought I'd post the charts...

Wow, that is quite the storm the Canadian is showing for north Texas up into Oklahoma. If such a scenario played out, we could be looking at significant accumulations of winter precipitation up here.

It doesn't look so promising down in the Houston area though. The precipitation would probably be ended by the time the atmosphere was cold enough for snow. There could be some mixing with (or a changeover to) sleet though near the conclusion of the event; especially as you head northwest of the city. For a better winter weather event down there, you would want the surface low to traverse a path further south.

Of course, we still have a long way to go before any scenario can be taken seriously. Until the ECMWF, GFS and CMC start coming more in line with one another; next week will remain somewhat of a mystery. The only thing I am really feeling confident in right now is that early to mid next week will likely be cold across the southern plains.

[TexasMetBlake]

As of 138 hours, the low in the Pacific is definitely on the move. This is in contrast to previous gfs runs and more in line with the Euro. This is interesting. Let's see how it unfolds...

[srainhoutx]

12Z GFS through 138 hours has the front passing Sunday evening in our area and our 500mb trough entering the W Coast in CA a bit stronger that previously model. We shall see.

[TexasMetBlake]

See for yourself:

12z:



06z:

[TexasMetBlake]

12z shows a split flow over the south and the low is shunted northward into Colorado and sheared out. The GFS has shown this solution now for a while. The 6z and 12z look a good bit different again. The 12z shows a well pronounced ridge over the midwest at 162 while the 6z did not.

[TexasMetBlake]

12z gfs 162 hr:

[srainhoutx]

Also of note is the development of a Coastal trough/low in S TX near the 162 hour timeframe. The GFS appears to be trending in the right direction at this time.

[don]

Yea it seems like the 12z GFS was trying "so hard" to spin up a gulf low but it shears out the system over the Rockies with little energy left to spin up anything in the gulf...

[Portastorm]

Coastal lows or troughs almost always form when upper level energy approaches Texas from the west. I see the 12z GFS depiction as a definite good sign (that is, if you want wintry weather next week!).

[srainhoutx]

The 12Z GGEM (Canadian) just completed and suggests the Upper Low near Southern CA and an approaching shortwave in the Desert SW.

[srainhoutx]

For extremeweatherguy...

[srainhoutx]

The 12Z GFS Ensembles (500mb) at hour 144 suggest that some members are latching onto the Pacific/Western closed low idea. Still a ways to go, but the trends are certainly encouraging.

[srainhoutx]

The 12Z GFS ensemble 850's have some members 'hinting' as well...hour 180 & 192...

[srainhoutx]

The 12Z Euro is running and through hour 120 suggests the front is diving S into TX as the Upper Air Feature begins to swing into the West Coast.

[srainhoutx]

By hour 144 the Upper Air feature is nearing the CA Coast and the front has passed through TX.

[TexasMetBlake]

Wow, big change on the Euro...and not for the better. At 168, it shows the low well north of our area.

[srainhoutx]

Hour 168 suggests a more open Upper Low than previously modeled by the Euro, but does show a stout low in NM and precip breaking out along the front range of the Rockies into the TX/OK Panhandles.