TX winter wx thread: Spring-like pattern

[Extremeweatherguy]

Well the models were generally correct with the Thanksgiving cold spell, so will they do well again? If so, then we are in for one heck of a winter storm by December 3rd and 4th. Check out the 18z GFS run...

1050mb+ high pressure and very cold air slides out of Canada next Sunday: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_216l.gif

Arctic front reaches Texas on Monday the 3rd with quickly falling temperatures and snow in north Texas: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_240l.gif

By Tuesday, winter precipitation reaches well into the state, including Houston. This kind of setup would even be favorable for decent accumulations of snow/ice in central and southeast Texas as temperatures Tuesday afternoon would still be below freezing with lots of precipitation and below 0C 850mb temperatures: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_252l.gif , http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_264l.gif , http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_276l.gif

Now I know the models can and will change some over the coming days, but if the 18z GFS run were to play out exactly, then we would be looking at one of Texas' worst winter storms in a long time with accumulations of snow and sleet likely for many areas between December 3rd and December 5th.

BTW - To give you an idea of how CRAZY this run is. I just looked at the GFS snow accumulation maps, and the 18z is calling for a swath of 10-15" amounts across the city of Houston and into Louisiana by the morning of Wednesday, December 5th!

Now amounts like that are not impossible (1895 and 2004 come to mind), but they are very, very unlikely for southern areas of Texas. None the less though, it is still very interesting to see a model showing something like this in the Day 10-12 range.

[Kennethb]

I'm not sure about the precipition potential, but iT appears that a early December cold snap is possible.

[AL Chili Pepper]

I remember seeing the GFS do that last year only to fizzle on following runs. It would be fun to see something like that play out once in a while.

[Ed Mahmoud]

The GFS predicted the Christmas Eve South Texas snow event in numerous runs about ten days out, lost it for a few runs about a week out, then got it back. IIRC.

[Ed Mahmoud]

EWG, just noticed, rather warm 1000-500 mb thicknesses, which might suggest a rain to prolonged ice and sleet before a little snow at the very end.


I mean, if I did get too worked up over models over 10 days out.

Although, European does seem to suggest a cold front approaching in 10 days.


With an upper low back over the Northern Baja, which might send disturbances up and over the cold air mass.





But, if you do nail this from 12 days out, I'll vote for you as member of the month.

[PTrackerLA]

Let's see if the 00z GFS shows a similar event, then I'll start to bite . Looks like we're getting into an almost El-Nino type pattern instead of drought and La Nina conditions...interesting.

[Extremeweatherguy]

The 00z GFS looks a bit weird. It's all over the place beyond 180 hours, and it seems to me like it is still getting it's act together and probably will not have a real good idea of the situation for another few days. One thing that still looks pretty likely is that an arctic airmass will settle into the United States during early December. But what is still a bit uncertain includes the strength of the high pressure involved, the level of cold in Canada at the time and where/when precipitation sets up across the United States. As of the 00z run, the situation doesn't look nearly as "wintry" for Texas, but this is almost certain to go back and forth. Hopefully by next weekend we will finally have a good idea of what to expect...

BTW - As for JB's evening thoughts >> He thinks this has potential to be one of the strongest cold outbreaks of the winter. He thinks the cold will first come into the NW next weekend and then spread down the plains and into the east early the following week.

[double D]

The 12z/24 builds a 1052 high in western Canada, but still pushes most of the cold air east. I just don't see this arctic air pushing east like that with such a dense arctic air mass. This might be a case where the GFS struggles to get a handle on the upcoming arctic blast.

[Extremeweatherguy]

The 12z/24 builds a 1052 high in western Canada, but still pushes most of the cold air east. I just don't see this arctic air pushing east like that with such a dense arctic air mass. This might be a case where the GFS struggles to get a handle on the upcoming arctic blast.

yeah, this kind of struggle is nothing unusual with the GFS though...especially with arctic airmasses beyond the 180 hour timeframe. By late next week we should start to get a much better idea of the situation, and if a 1050mb+ high is still depicted, then I highly doubt this airmass would miss us or only give us a "glancing blow".

We saw similar things happen before our current cold shot too. In the very long range the model went back and forth between cold and warm, cold and warm before finally catching on to the colder look and sticking with it at about a week out from the event. We will probably see something similar happen this time as well.

[Extremeweatherguy]

12z ECMWF shows a pretty cold setup by December 4th...



BTW - - Here's the latest from the Climate Prediction Center...

http://www.cpc.noaa.gov/products/predic ... mp.new.gif
http://www.cpc.noaa.gov/products/predic ... mp.new.gif

[vbhoutex]

Well the models were generally correct with the Thanksgiving cold spell, so will they do well again? If so, then we are in for one heck of a winter storm by December 3rd and 4th. Check out the 18z GFS run...

1050mb+ high pressure and very cold air slides out of Canada next Sunday: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_216l.gif

Arctic front reaches Texas on Monday the 3rd with quickly falling temperatures and snow in north Texas: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_240l.gif

By Tuesday, winter precipitation reaches well into the state, including Houston. This kind of setup would even be favorable for decent accumulations of snow/ice in central and southeast Texas as temperatures Tuesday afternoon would still be below freezing with lots of precipitation and below 0C 850mb temperatures: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_252l.gif , http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_264l.gif , http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_ten_276l.gif

Now I know the models can and will change some over the coming days, but if the 18z GFS run were to play out exactly, then we would be looking at one of Texas' worst winter storms in a long time with accumulations of snow and sleet likely for many areas between December 3rd and December 5th.

BTW - To give you an idea of how CRAZY this run is. I just looked at the GFS snow accumulation maps, and the 18z is calling for a swath of 10-15" amounts across the city of Houston and into Louisiana by the morning of Wednesday, December 5th!

Now amounts like that are not impossible (1895 and 2004 come to mind), but they are very, very unlikely for southern areas of Texas. None the less though, it is still very interesting to see a model showing something like this in the Day 10-12 range.

Please explain to me where you see the winter precip coming from. Unless I am reading the models wrong I don't see any winter type precip for our area with temps in the 40's and 50's.

[Ed Mahmoud]

vbhoutex- is it that you are looking at today's 18Z GFS, not yesterdays? Because I did look yesterday at the links, and while heights were too high for snow, the 850 mb freezing line was near HOU.

[gboudx]

vbhoutex- is it that you are looking at today's 18Z GFS, not yesterdays? Because I did look yesterday at the links, and while heights were too high for snow, the 850 mb freezing line was near HOU.

Yeah, EWG's post has dynamic links. The model output is different than yesterday.

[vbhoutex]

vbhoutex- is it that you are looking at today's 18Z GFS, not yesterdays? Because I did look yesterday at the links, and while heights were too high for snow, the 850 mb freezing line was near HOU.

Yeah, EWG's post has dynamic links. The model output is different than yesterday.

Must be because I know I wasn't seeing what he had posted or the 850mb freezing line near HOU. It was showing it a lot warmer than what he was stating.

[Extremeweatherguy]

yeah, today's 18z GFS run was not nearly as "wintry" as yesterday's. Yesterday's 18z run showed rain changing to freezing rain changing to sleet and then changing to snow across our area with widespread accumulations by the morning of Wednesday, December 5th.

[PTPatrick]

For what it is worth to the texans...Denver discussion todya mentions that Ensembles are in remarkable agreement out to 180 hrs with the amplification of the western trough and east pac ridge....going on to say this is similar to the setup from late november/early december of 1985....i checked the records and denver had 3 nights below zero and 3 records from the 30th to the 2nd.

[Ed Mahmoud]

On the one hand, snow would rock, and from past experience I know my palm trees can survive mid 20sF without even being wrapped, but I planted an orange tree to replace the wrapped, but still killed, lemon trees from the 2004 cold spells, and while oranges are hardier than lemons, they aren't that much hardier.


I know, I know, trying to grow tropical plants in a mid-latitude climate like Harris County. But, oddly enough, while a lot of trees start shedding leaves around here in late November and early December, the palms and citrus stay green year round.

One reason I haven't done banana plants, at least not yet, as while they seem to grow back well the following Spring after a freeze, they sure don't look good in the immediate aftermath.

[Portastorm]

I don't see much model support this morning for said "December Arctic Blast" at least per the American models. The GFS operational runs and the NCEP ensembles show the bulk of the really cold air to the northeast throughout the next 10 days.

[Extremeweatherguy]

I don't see much model support this morning for said "December Arctic Blast" at least per the American models. The GFS operational runs and the NCEP ensembles show the bulk of the really cold air to the northeast throughout the next 10 days.

The models still look pretty chilly to me. Though not as cold and wintry as the 18z a couple of days ago, both of the GFS and ECMWF continue to show a cold pattern setting up. The 6z GFS shows a 1056mb high forming up in NW Canada and then trying to push south during early December. The model run then goes on to bring us a prolonged period with highs in the 30s, 40s and 50s across most of the state and it even shows some wintry precipitation trying to reach north and central TX by December 7th ( http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_300l.gif ). The 00z ECMWF also looks cold with a high coming down the plains and supplying us with chilly air while a ULL forms out to our west and likely brings us some precipitation. Know I don't know exactly how cold or where there would be any wintry precipitation (since I didn't look at the model in-depth), but overall I would say that the ECMWF looks to show a generally chilly setup for our area.

[richtrav]

Ed

What kind of palm trees do you have? Most types grown in central TX can take temps below 25 unless you bought some of those ultratropical ones from the garden center. For citrus, tangerines are the hardiest of the widely eaten citrus, unless you live in the northern suburbs they should be fine unless an '89 type event comes along or you get a really early or late hard freeze (low 20s for an extended period). They can stand usually temps into the mid-to-upper teens in the middle of winter without serious injury (heck even people in Dallas have been growing them the past 5-8 years).

The winter climate of Texas fascinates me, probably since I've been growing subtropical plants since the '80s. I'm amazed at how the climate suddenly went from one extreme to the other after 1990