Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 5

[Ed Lizard]

The now famous polar vortex can stay away the rest of the Winter unless we get some Winter precip.

 

 

BTW, the fire ants and mosquitoes seem to have survived 20F temps in the past, I think that is wishful thinking

 

 

It may not effect Dallas, but right along toe coast the cold shelf waters from the cold Winter probably ruin our Spring thunderstorm season.  I can picture 70F+ dewpoints going to waste because the low clouds from that air crossing 50s/60sF water don't allow enough insolation to break even meager capping inversions.

[DoctorMu]

There's no doubt cold weather reduces insect pests in the Spring.  No one would expect irradication 

 

looks pretty boring for awhile.

[wxmx]

Actually day 8+ is starting to look a bit interesting...not mightily cold, but a potential mid/upper level disturbance may drop south into MX, as strong Aleutian low forms, while the west coast ridge flexes it's muscle...as long as the ridge doesn't progresses too far east (strong +PNA), the pattern looks good.

 

[DFWWeather]

Actually day 8+ is starting to look a bit interesting...not mightily cold, but a potential mid/upper level disturbance may drop south into MX, as strong Aleutian low forms, while the west coast ridge flexes it's muscle...as long as the ridge doesn't progresses too far east (strong +PNA), the pattern looks good.

 

test8.gif

 

Latest CMC ensemble mean from the same period is much like the most recent pattern, and colder for Texas. It is the one on the far right below. The GFS looks suspect with too big a trough in Gulf of Alaska and too low amplitude ridge on West Coast positioned too far east with positive PNA. Blocking on all models out in the Atlantic may argue for a less progressive cold shot as well.

[Ed Lizard]

OT- based n the morning readings of NWS HGX AFDs, I expected meh showers, and was pleasantly surprised by some moderate showers.

 

I don't always post to complain.

[CranberryWX]

A little over 2" of rain yesterday in my back yard. Hardly rained at work closer to town.

[Srain]

Just emptied 1.2 inches out of the old rain bucket. This rain is sorely needed after those extremely low dewpoints.

[DFWWeather]

Houston, I think we have a problem. CMC does not agree with GFS and ECMWF with mean pattern (I mean night and day's difference). Ironically, the teleconnection indices would argue for the CMC output not the GFS or ECMWF. The CMC pattern below would put Texas in the deep freeze:

 

[Srain]

Another chilly morning here in NW Harris County where temperatures have dropped to the mid 30's. Those temperatures will rebound nicely today ahead of a re inforcing cold front arriving tonight with an even colder front arriving Thursday as a fast progressive NW flow remain the theme this week. The Marathon weather still looks nice for the runners, but yet another front may arrive late Sunday into Monday continuing the dry weather pattern.

Changes are beginning to show up in the longer range computer guidance suggesting that a broad trough will develop across North America as the Western Ridge breaks down and that pesky -EPO/-WPO regime becomes re established and a strong Ridge develops across the Gulf of Alaska and noses all the way into the interior of our 49th State. The deterministic and ensemble guidance are once again developing a pattern that looks very similar to what we witnessed beginning in mid last November and continued into early January. While it is likely that we have seen the 'coldest' air of our Winter Season, it certainly does not mean winter is over. If such a pattern does in fact does develop toward the end of January/early February, climatology suggests our greatest threats for wintry weather are just ahead as upper air disturbances ride S along or just W of the Inter Mountain West into the base of the trough tapping Gulf moisture allowing precip albeit somewhat light to develop across our Region and strengthen as those storm systems organize over Colorado/New Mexico/Texas and Oklahoma and turn NE. Enjoy the relative warm/dry weather while it lasts. Changes may well be lurking in about a 7-10 days.

 

 

[DFWWeather]

Srain - I certainly agree. For awhile there, I thought there might be a weaker Arctic shot mid month, but that isn't quite the case (although the models this week have been trending colder for the next couple of fronts at DFW). It is looking more possible that another round of very cold air may try to spill into the United States toward the end of the month into early February. Latest 12z GFS, certainly seeing the possibilities. Overall, this winter as been about stout ridging into Alaska and over the poll or over the west coast, something I haven't seen persist this long for quite sometime. This time around though I feel the trough axis may be a little more displaced westward with more of a trough retrogression overtime, than what we saw earlier in the month. The Plains into the Ohio Valley may see the brunt of this cold as ridging may try to hold along the east coast, much like what Srain describes above that occurred in late November to early December. I wouldn't at all be surprised for another ice or snow event through much of the Southern Plains in this pattern.

[Quixotic1]

The retrogression of the EC trough looks odd, however I am much more hopeful than a week ago.  Yay -EPO. 

[DFWWeather]

The retrogression of the EC trough looks odd, however I am much more hopeful than a week ago.  Yay -EPO. 

 

I think very plausible as the west coast ridge will migrate to offshore pumping into Alaska shifting the EC trough a little westward. It should encompass much of the eastern US from the Rockies eastward.

[bubba hotep]

I like that we are finally starting to see some cold anomalies show up in far western Canada towards the end of the the GEFS runs.  That combined with the EPO forecast has me thinking we could see a cold start to February.  Now if we could just get some blocking to drive that cold down the spin of the Rockies and lock it in place

[Srain]

The teleconnection indices continue to advertise a -EPO nearing the 3 to 3.5 range with a slightly negative WPO. The deterministic 06Z GFS as well as the 00Z Euro are suggesting a very stout GOA Ridge with abundant short wave energy dropping S from Canada. The trend the past couples of cycles has been to shift the colder air a bit further W. It will be interesting to see if the guidance continues this trend over the next 5-7 days. What raises an eyebrow is a noisy sub tropical jet that appears to be developing after the cold air arrives.

 

 

[Ed Lizard]

KHOU-TV forum down until November for maintenance.  I assume they meant 2014, not 2013.

 

 

Anyway, I suspect most of the cold air with the ~1040 mb high over Montana heads more Southeast than South, but who knows when a thin layer of very cold, dense air might want to leak down the Lee of the Rockies.  I think that 850 mb temp map might have another isotherm inside the labelled -32ºC isotherm, which would be pretty cold, even in American units.

 

 

[DFWWeather]

12z ECMWF and 12z GFS operational runs have both moved the trough a bit further west and the ridge further west and more amplified for the end of the month Arctic blast which should affect almost everyone from the Rockies eastward in some capacity. The 12z GFS has gone bonkers with ice and snow in Texas at that time frame. This should be interesting to follow the next few days! Here is the ensemble mean pattern from the ECMWF, GFS, and CMC:

 

 

The polar vortex doth returneth?

[Portastorm]

GFS and Euro seemed to have backed off overnight on the idea of a retrograding pattern late month.

[DFWWeather]

GFS and Euro seemed to have backed off overnight on the idea of a retrograding pattern late month.

 

Only the operational runs of the GFS and ECMWF and the ensemble mean of the ECMWF. However, the ensemble mean of the CMC and GFS are still very much on board. The teleconnective signals point to major cold, so this may be a fluke run.

 

Both the 12z GFS and ECMWF operational runs are still on board with widespread major cold from the Rockies to the east coast by the end of the month. How cold it gets here in Texas, still is very uncertain at this time, but it will get cold here and cold enough for ice/snow provided that adequate moisture and a system is around to provide lift. As I stated above, the teleconnective signaling is pointing toward a cold air outbreak and perhaps some blocking for a longer duration of the cold than what was experienced earlier in the month. I expect this pattern will probably carry over to much of the second week in February or even as long as week three before relaxing. Granted at this time, it does appear the very worst of the cold will be in the Ohio valley southeast relative to averages. So places like Atlanta, may be in for some whacky temps (6°F seen earlier this month) over the next few weeks. However, I do believe the trough to be far enough west to perhaps have a chance to out do the 15°F temp seen earlier this month at DFW - we will see!

[bubba hotep]

Only the operational runs of the GFS and ECMWF and the ensemble mean of the ECMWF. However, the ensemble mean of the CMC and GFS are still very much on board. The teleconnective signals point to major cold, so this may be a fluke run.

Both the 12z GFS and ECMWF operational runs are still on board with widespread major cold from the Rockies to the east coast by the end of the month. How cold it gets here in Texas, still is very uncertain at this time, but it will get cold here and cold enough for ice/snow provided that adequate moisture and a system is around to provide lift. As I stated above, the teleconnective signaling is pointing toward a cold air outbreak and perhaps some blocking for a longer duration of the cold than what was experienced earlier in the month. I expect this pattern will probably carry over to much of the second week in February or even as long as week three before relaxing. Granted at this time, it does appear the very worst of the cold will be in the Ohio valley southeast relative to averages. So places like Atlanta, may be in for some whacky temps (6°F seen earlier this month) over the next few weeks. However, I do believe the trough to be far enough west to perhaps have a chance to out do the 15°F temp seen earlier this month at DFW - we will see!

I'm still liking the 1st part of February as the timeframe that we will see our coldest air. Even with the modeled cold dumps over the next couple of weeks I'm seeing a setup that will allow cold anomalies to really build in our source region.

[DFWWeather]

I'm still liking the 1st part of February as the timeframe that we will see our coldest air. Even with the modeled cold dumps over the next couple of weeks I'm seeing a setup that will allow cold anomalies to really build in our source region.

I fully agree with you. I just said the end of the month cause the last weekend seems to start the pattern into the US in general. BTW the 12z gfs and ecmwf ensemble means are wicked ridiculous with heights way over the pole. CPC also noted the potential for record breaking cold in today's discussion. Gonna be interesting!

[bubba hotep]

After taking a quick look at things this morning, I still like the early February period from maybe the 3rd - 10th.  We shall see what happens but anything has to be better than this boring dry NW flow with glancing cold shots…

[Quixotic1]

After taking a quick look at things this morning, I still like the early February period from maybe the 3rd - 10th. We shall see what happens but anything has to be better than this boring dry NW flow with glancing cold shots…

AFD for FWD yesterday mentioned a change from a 5 wave pattern to a 4 wave. Lets hope this shakes things up enough to get rid of the blasted NW flow and get the gulf back in business.

[bubba hotep]

The GEFS continues to build a nice area of cold anomalies across our source region towards the end of the month and the 18z GFS brings the fantasy land pain at the end of the run

 

 

[Srain]

Interesting little short wave suggested by the 00Z Euro and the 00Z/06Z GFS late this coming week dropping down the back side of the big Eastern trough and arriving after a glancing Arctic front passes Texas/Louisiana on Thursday with 1048mb Arctic High just to our N. The guidance has been slowly shifting the colder air W and the operational guidance is suggesting over running precip as a Coastal trough develops, some of it of the wintry nature developing this coming Friday into Saturday. Temperatures may struggle to make it out of the low to mid 30's for highs if the guidance is correct.

 

 

 

 

 

[1900hurricane]

Yep, definitely made me raise an eyebrow. The possible event is also within 120 hours, which makes it doubly-intriguing.

[bubba hotep]

Interesting little short wave suggested by the 00Z Euro and the 00Z/06Z GFS late this coming week dropping down the back side of the big Eastern trough and arriving after a glancing Arctic front passes Texas/Louisiana on Thursday with 1048mb Arctic High just to our N. The guidance has been slowly shifting the colder air W and the operational guidance is suggesting over running precip as a Coastal trough develops, some of it of the wintry nature developing this coming Friday into Saturday. Temperatures may struggle to make it out of the low to mid 30's for highs if the guidance is correct.

 

And look what the 12z GFS finds...  Not really a fan of this since 850s are warm and the thickness looks crappy.

 

 

The interesting thing is that the GFS had something along these lines in the long range but the dropped the thought, IIRC.

[Srain]

And look what the 12z GFS finds...  Not really a fan of this since 850s are warm and the thickness looks crappy.

 

 

The interesting thing is that the GFS had something along these lines in the long range but the dropped the thought, IIRC.

Fairly typical late January winter storm for our Region. We tend to see more in the way of ice and sleet events with the 5H pattern that is expected. Many of our notable ice storm events in the 60's and 70's would occur when a short wave dropped S into the Four Corners Region and stalled allowing for a warm nose over riding the cold air at the surface. The pattern depicted by the various model schemes is not all that different than what we experience late in November.

[Ed Lizard]

Euro a smidge too warm for a school day Friday, but somehow it feels like the Euro isn't automatic to beat the GFS anymore.

Euro comes close. No cigar.



At least we have something that isn't two weeks away that may or may not happen to talk about.

GFS might end as snow, small region above freezing isn't much above freezing... Or partial melting and refreezing, Snow pellets. Assuming GFS is correct, as Euro not quite feeling it.

[Ed Lizard]

^^ Other thought, since only a small bit of the saturated layer is cold enough for dendrite growth, it might be freezing drizzle, with maybe a few flakes, and a random sleet pellet, all at the same time...


The profile 12 hours before is a snow profile that melts near surface (saturated temps way, way, way cold enough, -40C so maybe they'll be a transition from rain to snow that ends at a freezing drizzle or snizzle.



If only the NIU page allowed 6 hour forecast soundings.

[Srain]

The over night guidance has trended slight faster with the Arctic front and a bit colder and the Euro trended a bit stronger and in a bit better agreement with the GFS solution suggesting increased QPF as the Arctic boundary stalls along Coastal Texas/Louisiana and a Coastal trough/wave of low pressure develops near of just E of Brownsville. This would tend to suggest a classic NW Gulf Coast freezing rain event, if it verifies.