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Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:10 am
by wxman57
I'm comparing today's 12Z run with yesterday's 18Z run and so far the 12Z run is not as cold and considerably slower with the southward push of cold air (through 90hrs).

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:12 am
by srainhoutx
At hour 90, the GFS suggests storms firing in S TX/Middle TX Coast (MCS/Meso Convective System) as well has high pressure building across AK ridging N and beginning to tap that cold air in Eurasia.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:20 am
by srainhoutx
By hour 126, the storms have passed over SE TX and are well E. High pressure builds strongly in W AK. 1050+mb are common along the lee side of the Rockies in W Canada building S. The front is still locked up in the Southern Plains, though.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:22 am
by brazoria121
srainhoutx wrote:By hour 126, the storms have passed over SE TX and are well E. High pressure builds strongly in W AK. 1050+mb are common along the lee side of the Rockies in W Canada building S.
so its basically starting to "come together"?

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:23 am
by brazoria121
srainhoutx wrote:By hour 126, the storms have passed over SE TX and are well E. High pressure builds strongly in W AK. 1050+mb are common along the lee side of the Rockies in W Canada building S.
so its basically starting to "come together"?

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:24 am
by srainhoutx
brazoria121 wrote:
srainhoutx wrote:By hour 126, the storms have passed over SE TX and are well E. High pressure builds strongly in W AK. 1050+mb are common along the lee side of the Rockies in W Canada building S.
so its basically starting to "come together"?
Yep. By hour 144, 1057mb high in Western Canada. Front is pushing S and is offshore of the TX Coast.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:26 am
by ronyan
The NWS changed their forecast high from 41 on Tuesday to 55 here. LOL great job on nailing that one, it will probably be back down near 40 again by the time we get within 3 days.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:32 am
by srainhoutx
By hour 168, 1054mb high in the NW Territories with strong CCA building well S along the TX Coastal Plain. High pressure over AK is further E this run and rather strong. Continous feed from Eurasia dropping across the Polar region.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:45 am
by wxman666
Hi folks! I don't usually interact with the forum all too often but I do like to pop in to grab as much information as possible when models are trending towards some extreme/severe weather. That said, I do have a couple questions. If anyone has looked at the latest model guidance today (1/5) (approximately 10:40 AM CT right now), I need to know if they are still trending towards a possible severe weather scenario this Saturday for Houston and surrounding suburbs. As of the early morning NWS Hou/Gal FD, models were showing a negatively tilted trough, favorable diffluence and upper level dynamics on Saturday. Is that still the case...and is this setting the stage for rotating supercells/iso. tornadoes Saturday afternoon/evening? Secondly, regarding the arctic blast for next week...looks like the models are starting to vacillate somewhat after a few days of consistency. Is this to be taken as a significant alteration to the forecast? Gene Norman said on his video blog last night that it appears moisture may line up sometime late next week along with the cold temperatures, and that can sometimes cause concern for wintry precipitation...so are we still looking at that as a possibility? Sorry for throwing so much out at once...I have read through the previous posts but need some updated info and any answers are greatly appreciated. Thanks.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:46 am
by srainhoutx
At hour 192, 1054mb high sliding S near MT. Cold air still in place across TX, although not as cold. Beyond that a storm crashes into the Pacific NW and the pattern turn more zonal.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:52 am
by srainhoutx
wxman666 wrote:Hi folks! I don't usually interact with the forum all too often but I do like to pop in to grab as much information as possible when models are trending towards some extreme/severe weather. That said, I do have a couple questions. If anyone has looked at the latest model guidance today (1/5) (approximately 10:40 AM CT right now), I need to know if they are still trending towards a possible severe weather scenario this Saturday for Houston and surrounding suburbs. As of the early morning NWS Hou/Gal FD, models were showing a negatively tilted trough, favorable diffluence and upper level dynamics on Saturday. Is that still the case...and is this setting the stage for rotating supercells/iso. tornadoes Saturday afternoon/evening? Secondly, regarding the arctic blast for next week...looks like the models are starting to vacillate somewhat after a few days of consistency. Is this to be taken as a significant alteration to the forecast? Gene Norman said on his video blog last night that it appears moisture may line up sometime late next week along with the cold temperatures, and that can sometimes cause concern for wintry precipitation...so are we still looking at that as a possibility? Sorry for throwing so much out at once...I have read through the previous posts but need some updated info and any answers are greatly appreciated. Thanks.

The severe weather potential looks to be there in some form or fashion Saturday evening into Sunday. Regarding the Arctic Air, the past 3 runs of the GFS have trended warmer and little if any precip following after that front pass. This is may well change, though. As wxman57 and others have stated, we really need to 'see' this air mass before some firm answers are given regarding temps and such.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:54 am
by wxman57
12Z GFS is certainly warmer than the past few runs (which were warmer than yesterday's 12Z and 18Z runs). Only a moderate freeze in north Houston next Wednesday then a gradual warm-up. Now that doesn't mean it's what is going to happen. Like I keep saying, let's wait for the cold air to ACTUALLY build into northern Canada before we make any conclusions about next week.

Here are the meteograms from the 12Z GFS:
Image

Image

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:57 am
by brazoria121
Is anyone else having problems logging in to the forum from their computer

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:58 am
by wxman666
srainhoutx wrote:
wxman666 wrote:Hi folks! I don't usually interact with the forum all too often but I do like to pop in to grab as much information as possible when models are trending towards some extreme/severe weather. That said, I do have a couple questions. If anyone has looked at the latest model guidance today (1/5) (approximately 10:40 AM CT right now), I need to know if they are still trending towards a possible severe weather scenario this Saturday for Houston and surrounding suburbs. As of the early morning NWS Hou/Gal FD, models were showing a negatively tilted trough, favorable diffluence and upper level dynamics on Saturday. Is that still the case...and is this setting the stage for rotating supercells/iso. tornadoes Saturday afternoon/evening? Secondly, regarding the arctic blast for next week...looks like the models are starting to vacillate somewhat after a few days of consistency. Is this to be taken as a significant alteration to the forecast? Gene Norman said on his video blog last night that it appears moisture may line up sometime late next week along with the cold temperatures, and that can sometimes cause concern for wintry precipitation...so are we still looking at that as a possibility? Sorry for throwing so much out at once...I have read through the previous posts but need some updated info and any answers are greatly appreciated. Thanks.

The severe weather potential looks to be there in some form or fashion Saturday evening into Sunday. Regarding the Arctic Air, the past 3 runs of the GFS have trended warmer and little if any precip following after that front pass. This is may well change, though. As wxman57 and others have stated, we really need to 'see' this air mass before some firm answers are given regarding temps and such.
That was kind of my thinking on it...considering the NWS has bumped temps up fairly significantly Tuesday (Cypress up from a high of 39 to 53). I imagine we will have little confidence until sometime next week. NWS Houston seems reluctant to believe the model trends downplaying things at this particular point in time. Thanks for the speedy reply btw.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 10:59 am
by wxman666
brazoria121 wrote:Is anyone else having problems logging in to the forum from their computer
Not for me.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 11:00 am
by srainhoutx
brazoria121 wrote:Is anyone else having problems logging in to the forum from their computer
I just checked our server, and all is well that I can see.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 11:09 am
by srainhoutx
The CMC (Canadian) drops a convective bomb at hour 96 across TX and sweeps the cold front straight S into S TX and offshore by hour 132...1061mb High in AK as well...EDIT to add: by hour 144 a 1065mb High over AK and the front has pushed S all the way to Veracruz, MX...

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 11:12 am
by wxman666
srainhoutx wrote:The CMC (Canadian) drops a convective bomb at hour 96 across TX and sweeps the cold front straight S into S TX and offshore by hour 132...1061mb High in AK as well...
Oh my gosh...that looks pretty nasty! How reliable is the CMC in these situations?

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 11:15 am
by srainhoutx
wxman666 wrote:
srainhoutx wrote:The CMC (Canadian) drops a convective bomb at hour 96 across TX and sweeps the cold front straight S into S TX and offshore by hour 132...1061mb High in AK as well...
Oh my gosh...that looks pretty nasty! How reliable is the CMC in these situations?
All the models are struggling with that feature as noted in the HPC discussions I posted earlier. With that said, I'd expect the SPC to start ramping up there interest as we get closer.

Re: January Weather Discussion. Severe Threat/Cold Blast Com

Posted: Wed Jan 05, 2011 11:15 am
by biggerbyte
We do have a rain and potential severe storms event this weekend. It is odd now that the weather then could very well be the highlight of events for some days. At the moment, taking everything into consideration, including current model runs, next weeks "cold" could end up being the little train that did not. Same ole, Same ole someone mentioned earlier. Beyond today, I'm not even going to revisit next weeks forecast until Saturday. In the meantime, my area got lots of rain last night.
We need to watch over the weekend now for pretty much a good chance for more good rains.