Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 7

[wxmx]

For the early Feb threat, wintry precip chance comes down to if there's any s/w riding the backend of the trough led by the main piece of energy that's lifting NE. It's a similar setup to what's currently on, where there was a piece of energy that dug well south into MX. In the February forecast, it doesn't seem to be a strong enough s/w, hence the trough doesn't dig as much, and the overall setup is dry.

[aggiegeog]

For the early Feb threat, wintry precip chance comes down to if there's any s/w riding the backend of the trough led by the main piece of energy that's lifting NE. It's a similar setup to what's currently on, where there was a piece of energy that dug well south into MX. In the February forecast, it doesn't seem to be a strong enough s/w, hence the trough doesn't dig as much, and the overall setup is dry.

It seems like the models often send everything out with the main shortwave when often some does hold back.

[aggiegeog]

And it is the longest stretch in our weather history of not falling into the single digits. Climatology says we should do this 1 out of every 5 years. I'm beginning to question if it will ever be possible again for DFW. However we are still within the statistical range of falling below zero, which should be one 1 in 30 years. Last time was December 23, 1989. But that really may be impossible to achieve.

The only chance I could see is for a massive EPO something in the -5SD range and solid plains snowcover and snow on the ground here.

[bubba hotep]

I had to come down to work, but it's still snowing, and at a moderate rate. Probably nearing 2-3" when I left.

 

 

Great pics! We'll have to hook up the next time I'm down that way for work so that you can show me the trail up there.

[bubba hotep]

I wouldn't punt the first two weeks of February yet.  

 

I'm getting more pessimistic by the day. I have growing concerns that we will stay dry into March. 

[aggiegeog]

I did not expect the 26 I got down to this morning. We have had many nights in the 20s this season but only one below 26. Next week should provide at least one more night below 26.

[wxmx]

It seems like the models often send everything out with the main shortwave when often some does hold back.

That's true, and I have been looking for that in the models, but still not there. The GGEM, with all it's limitations, it's actually decent at detecting the backend s/w's.

 

 

Great pics! We'll have to hook up the next time I'm down that way for work so that you can show me the trail up there.

You come here often? Sure, shoot me a message next time you plan coming here.

 

Yesterday the sky cleared just in time for some awesome views of the mountains. I even peeked at a peak that's behind the front range, and the top was completely white, as in probably 1-2 feet+ of snow. That peak is at 3000m+. I have no picture of that one, hopefully someone took one.

 

[aggiegeog]

I am planning to head up to NM next week so I will be watching the 2/4-8 period for any potential travel issues. Biggest concern looks to be early in the second week of Feb where some 06Z GFS ensemble members hint at a storm.

[bubba hotep]

That's true, and I have been looking for that in the models, but still not there. The GGEM, with all it's limitations, it's actually decent at detecting the backend s/w's.

 

 

You come here often? Sure, shoot me a message next time you plan coming here.

 

I used to go about once a year for work but haven't been in a few years. However, the program is rotating back under me, so I will probably be traveling to Mexico more frequently again. 

[bubba hotep]

There isn't anything "classical" showing up in the ensemble means yet but there are plenty of members across the different models that seem to be picking up on the transition to a period of better winter weather threats for Texas post Feb 6/7. It looks like a lot of them are just brute force type setups - crushing cold with an active jet but better system spacing than we saw in January.  

[DoctorMu]

Awesome stuff wxmx.

[aggiegeog]

GFS ensemble members continuing to show potential for a snowy start to the second week of Feb followed by bitter cold (some -15C 850s showing up in northern TX on some members).

[Quixotic1]

-EPO popping with a vengeance.  +PNA.   AO dropping too.  

[aggiegeog]

Hope the PNA stays neutral. Even -PNA would be OK just hope no strong +PNA. Looks like we will get our -EPO so Canada stops being flooded by warmth.

[wxmx]

Hope the PNA stays neutral. Even -PNA would be OK just hope no strong +PNA. Looks like we will get our -EPO so Canada stops being flooded by warmth.

The setup to get brutal cold far south is dynamic. Many of you have heard of the McFarland setup, and many think of it as a big -EPO. But that's just part of the equation. The -EPO breaks the arctic dam, and floods W Canada with very dense/cold air. It's very very rare to get a big EPO ridge that goes all the way south, it's usually undercut by the polar jet near the Canadian/CONUS W Coast, and favors a -PNA. To get that cold air south, we need the W Coast ridge to build, usually from the SW to the NE into Canada to tap into the frigid air and send it south directly. That is, go from a -PNA to a +PNA. The overall period PNA is near neutral or slightly positive. A very strong +PNA would probably send the cold air to the SE CONUS.

[aggiegeog]

The setup to get brutal cold far south is dynamic. Many of you have heard of the McFarland setup, and many think of it as a big -EPO. But that's just part of the equation. The -EPO breaks the arctic dam, and floods W Canada with very dense/cold air. It's very very rare to get a big EPO ridge that goes all the way south, it's usually undercut by the polar jet near the Canadian/CONUS W Coast, and favors a -PNA. To get that cold air south, we need the W Coast ridge to build, usually from the SW to the NE into Canada to tap into the frigid air and send it south directly. That is, go from a -PNA to a +PNA. The overall period PNA is near neutral or slightly positive. A very strong +PNA would probably send the cold air to the SE CONUS.

Yep, the issue we sometimes run into with -EPO is when the PNA goes too positive sending the cold east instead of south and putting us in NW flow aloft. If the PNA can hold on the - or = side then you can get SW flow aloft so we can get moisture involved over the cold air.

[wxmx]

Yep, the issue we sometimes run into with -EPO is when the PNA goes too positive sending the cold east instead of south and putting us in NW flow aloft. If the PNA can hold on the - or = side then you can get SW flow aloft so we can get moisture involved over the cold air.

Yes, a strong +PNA usually does that. You still need a ridge, but not fully over land, but on the west coast and tilted NE/SW. That provides the positive titled trough upstream.

[aggiegeog]

The 12Z GFS Ensemble member 18 has the almost an ideal winter scenario for Texas especially E TX. 1050+mb high over Colorado associated with a deep trough digging way into Mexico generating a Gulf low. 6"+ snow over E TX with 850mb Ts in the -10s. That right there would be how to finally get DFW below 10 possibly.

The 12Z GFS Ensemble mean has snow for a good portion of the state and cold temps throughout after this weekend. We look to stay on a pattern of early week storm then cold then warming by weekend then repeat.

[aggiegeog]

The early next week storm looks like it will drop huge amounts of snow over the N NM mountains. I could see favored places like Ski Santa Fe getting 40"+ and the other Sangre resorts getting 24"+. Areas north of I-40 in NM and the Panhandle could see significant snow also.

[DFWWeather]

Winter 2015-2016 is in the running to being one of the hottest winters on record for DFW. To date, we have not seen a low temperature of 25°F or lower. There has never been a cold season on record where the temperature failed to fall to 25°F or lower. Coldest temperature so far this winter has been 27°F. We have also not seen any single day this winter with a high temperature lower than 40°F. Coldest high temperature so far has been 41°F. There have only been two winters of this occurring.

[aggiegeog]

Winter 2015-2016 is in the running to being one of the hottest winters on record for DFW. To date, we have not seen a low temperature of 25°F or lower. There has never been a cold season on record where the temperature failed to fall to 25°F or lower. Coldest temperature so far this winter has been 27°F. We have also not seen any single day this winter with a high temperature lower than 40°F. Coldest high temperature so far has been 41°F. There have only been two winters of this occurring.

I expect both of those to fall within 14 days, but it may be a close call. I would say it has been a very moderate winter as anomalies are not extreme at all, typical El Nino.

[DFWWeather]

I expect both of those to fall within 14 days, but it may be a close call. I would say it has been a very moderate winter as anomalies are not extreme at all, typical El Nino.

 

I don't know being nearly 80°F in January and +6.5 for December is pretty anomalous. Also, if we do go the whole cold season without reaching 25°F that would be the most extreme that you could get. That is something you just don't see very often, if ever.

 

Having said that though and like you mentioned above, I do like the signals coming up for week 2 of Feb. Potential -EPO with recent stratospheric warming episode at pole could be just what we need to turn things around. Both Canadian and GFS mean 500m pattern both show potential for strong cold blast. However, ECMWF is not as amplified with pattern. This will be something to watch! This will be our truly last shot for something significant before climatology starts in strongly against us.

[aggiegeog]

I don't know being nearly 80°F in January and +6.5 for December is pretty anomalous. Also, if we do go the whole cold season without reaching 25°F that would be the most extreme that you could get. That is something you just don't see very often, if ever.

 

Having said that though and like you mentioned above, I do like the signals coming up for week 2 of Feb. Potential -EPO with recent stratospheric warming episode at pole could be just what we need to turn things around. Both Canadian and GFS mean 500m pattern both show potential for strong cold blast. However, ECMWF is not as amplified with pattern. This will be something to watch! This will be our truly last shot for something significant before climatology starts in strongly against us.

The first week of March has delivered the last two years, but I agree that as of now week 2 of Feb looks like our best shot.

[bubba hotep]

The setup to get brutal cold far south is dynamic. Many of you have heard of the McFarland setup, and many think of it as a big -EPO. But that's just part of the equation. The -EPO breaks the arctic dam, and floods W Canada with very dense/cold air. It's very very rare to get a big EPO ridge that goes all the way south, it's usually undercut by the polar jet near the Canadian/CONUS W Coast, and favors a -PNA. To get that cold air south, we need the W Coast ridge to build, usually from the SW to the NE into Canada to tap into the frigid air and send it south directly. That is, go from a -PNA to a +PNA. The overall period PNA is near neutral or slightly positive. A very strong +PNA would probably send the cold air to the SE CONUS.

 

The setup to get brutal cold far south is dynamic. Many of you have heard of the McFarland setup, and many think of it as a big -EPO. But that's just part of the equation. The -EPO breaks the arctic dam, and floods W Canada with very dense/cold air. It's very very rare to get a big EPO ridge that goes all the way south, it's usually undercut by the polar jet near the Canadian/CONUS W Coast, and favors a -PNA. To get that cold air south, we need the W Coast ridge to build, usually from the SW to the NE into Canada to tap into the frigid air and send it south directly. That is, go from a -PNA to a +PNA. The overall period PNA is near neutral or slightly positive. A very strong +PNA would probably send the cold air to the SE CONUS.

 

Image is small? I'll post a regular size when I get off the plane. I wouldn't bet on a true McFarland signature unless we see the southern stream die off. I don't know a true one that has occurred during a strong nino. (The most recent date that I have is '75, what are some more recent events?)

[Srain]

Meh, we've been running -1.73 below normal through yesterday @ IAH for January. Seeing a lot of trends via the ensembles that by mid next week, those departures will continue until at least mid February. We are getting a bit dry NW of Houston. Some moisture would be welcomed.

[DFWWeather]

Image is small? I'll post a regular size when I get off the plane. I wouldn't bet on a true McFarland signature unless we see the southern stream die off. I don't know a true one that has occurred during a strong nino. (The most recent date that I have is '75, what are some more recent events?)

December 1983 was huge McFarland as was December 1989. 83 produced worst freeze in years in Lower Rio Grande Valley and probably the worst on record for them.

[Srain]

83 took years to recover from agriculturally speaking from NE Mexico, the RGV and the Coastal Plain all the way into Southern Louisiana. The Lower Rio Grande Valley was just beginning to recover when the 89 event happened and set back full recovery another 3 to 5 years.

[bubba hotep]

December 1983 was huge McFarland as was December 1989. 83 produced worst freeze in years in Lower Rio Grande Valley and probably the worst on record for them.

 

What were the dates on those? I'll add those to the composite. Interesting signs that we might move through a window when the atmosphere may not look so ninoish. Opportunity for more extensive cold? 

[Quixotic1]

December 83 was from the 16th to the 31st. 89 was I believe the 20th. Those are legendary McFarland signatures. Don't see that yet.

[bubba hotep]

December 83 was from the 16th to the 31st. 89 was I believe the 20th. Those are legendary McFarland signatures. Don't see that yet.

Cool, I'll add those. Yea, I don't see any signs and actually have no interest in one. Dry and cold is not my thing

ETA: Both were during neg/neutral MEI periods. '83 was coming off a strong nino, so maybe this coming December.