Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 6

[vwgrrc]

Wow, 00z GFS is so close to something epic. The potential seems off the charts but will it be realized?

which system are you referring to? 

 

0z indicates a bit warmer the next Fri so basically it says another cold rain event. But well, 9 days out, you know

[ams30721us]

Welp...I'm hesitant to speak this far out this year, but if the 6z GFS is right, looks like the chances for A wintry mix of VERY cold rain/freezing rain & or Sleet is increasing across north and east Texas for Sunday night into Monday. In fact, the 6z is a bonafide winter storm across the area. Temps are actually modeled to drop into the 20s during the day Monday across East Texas. Quick glance closer at the GFS indicates the potential for enough deep cold air for more sleet, especially by midday Monday.

 

[bubba hotep]

Welp...I'm hesitant to speak this far out this year, but if the 6z GFS is right, looks like the chances for A wintry mix of VERY cold rain/freezing rain & or Sleet is increasing across north and east Texas for Sunday night into Monday. In fact, the 6z is a bonafide winter storm across the area. Temps are actually modeled to drop into the 20s during the day Monday across East Texas. Quick glance closer at the GFS indicates the potential for enough deep cold air for more sleet, especially by midday Monday.

The models seem to be finally locking in for this weekend but FWD said they are still leaning towards the conservative side of things. It looks like it could be an interesting event for everyone north of I-20.

[ams30721us]

The models seem to be finally locking in for this weekend but FWD said they are still leaning towards the conservative side of things. It looks like it could be an interesting event for everyone north of I-20.

Yea FWD used more of the Euro/00z GFS which left plenty of room for the conservative sides. But if these  trends from the 6Z continues, I would expect a much different tone for this afternoon update. Of course, this is all wondering if the GFS is on to something.

 

Snippet from SHV:

 

UNTIL A POWERFUL ARCTIC COLD FRONT MOVES

QUICKLY ACROSS THE AREA SAT NIGHT INTO EARLY SUNDAY. TEMPS TO FALL

DURG THE DAYTIME SUNDAY AS THIS COLDEST AIRMASS OF THE YEAR WORKS

ITS WAY INTO AREA. ANY PRECIP THAT CONTINUES FROM SUNDAY NIGHT

INTO THE DAYTIME MONDAY WILL LIKELY BE FRZG...ALTHOUGH MODELS ARE

NOT ALL IN LINE WITH HOW MUCH MOISTURE AND LIFT WILL BE PRESENT IN

THIS FRZG AIR. WITH SKIES FINALLY CLEARING TUESDAY AND

WEDNESDAY...BUT TO BE FOLLOWED BY MORE OVERRUNNING MOISTURE AND

WITH IT THE POSSIBILITY OF MORE QUESTIONABLE PRECIP TYPE LATE WEEK

TOWARDS END OF THE EXTENDED FCST PERIOD./VII/.

[Srain]

If the position of the cold upper trough is near California/Nevada, I suspect areas from West/Central Texas into the Northern areas of SE/E Texas into Louisiana may have a shot at some wintry mix. There is a warm nose about 700mb, but surface temperatures raise an eyebrow with IAH flittering with temperatures in the mid 30's. This one is going to be a forecasting challenge and may not be resolved until Sunday. Then late week as the upper trough begins to approach from the Desert SW, another shot of cold air arrives. Looks like next week will be our last shot of wintry weather for a while as we see a strong zonal flow develop.

[bubba hotep]

Yea FWD used more of the Euro/00z GFS which left plenty of room for the conservative sides. But if these trends from the 6Z continues, I would expect a much different tone for this afternoon update. Of course, this is all wondering if the GFS is on to something.

Snippet from SHV:

UNTIL A POWERFUL ARCTIC COLD FRONT MOVES

QUICKLY ACROSS THE AREA SAT NIGHT INTO EARLY SUNDAY. TEMPS TO FALL

DURG THE DAYTIME SUNDAY AS THIS COLDEST AIRMASS OF THE YEAR WORKS

ITS WAY INTO AREA. ANY PRECIP THAT CONTINUES FROM SUNDAY NIGHT

INTO THE DAYTIME MONDAY WILL LIKELY BE FRZG...ALTHOUGH MODELS ARE

NOT ALL IN LINE WITH HOW MUCH MOISTURE AND LIFT WILL BE PRESENT IN

THIS FRZG AIR. WITH SKIES FINALLY CLEARING TUESDAY AND

WEDNESDAY...BUT TO BE FOLLOWED BY MORE OVERRUNNING MOISTURE AND

WITH IT THE POSSIBILITY OF MORE QUESTIONABLE PRECIP TYPE LATE WEEK

TOWARDS END OF THE EXTENDED FCST PERIOD./VII/.

Yea,hopefully the models will come into agreement on the H5 setup out west but individual pulses of energy kicking out may not be settled until Sunday (as Steve pointed out in his post). The lift should be there, strong CAA with surface temps probably colder than currently modeled, just need some properly timed enhancement

[aggiegeog]

Monday is starting to look like a big event, but still have many model runs to go. Could be similar to Dec '13 or March '14. Then another potential winter weather event on Thursday. Temps will be very cold all week with maybe a blip of a warm-up between the storms.

[Roy]

Starting to get interesting finally. Could be something here, especially with it getting colder during the day...roads could get worse through the day.

[DFWWeather]

My all this excitement over just the 6z run of today's GFS? 6z and 18z GFS runs are nothing to base a forecast on for sure. The trend at H85 has been warming with each passing run since last week (not a good sign) for this time frame. If this continues, likely just another cold rain event with marginal surface temps. If we see significant trends in the 0z and 12z data from both the GFS and ECMWF the next couple of days, then I will start to get interested. As warm as it has been lately, we are going to need surface temps at least 27°F or lower for this to be a significant event.

[ams30721us]

My all this excitement over just the 6z run of today's GFS? 6z and 18z GFS runs are nothing to base a forecast on for sure. The trend at H85 has been warming with each passing run since last week (not a good sign) for this time frame. If this continues, likely just another cold rain event with marginal surface temps. If we see significant trends in the 0z and 12z data from both the GFS and ECMWF the next couple of days, then I will start to get interested. As warm as it has been lately, we are going to need surface temps at least 27°F or lower for this to be a significant event.

 

Actually, it's a known proven fact that the 6Z and 18Z are just important as any other run. Now, no I wouldn't base a forecast purely on one run of any model, but to deny and throw out the trends since the 18z, 00z, 06z and now 12z today is pure ludicrous. Especially when you compare with UKMET, Euro, and GEM...all of which also has wintry precip for the Sunday night into Monday time frame. Not saying, this is going to happen for certain, but it's def. not something to be ignored as these trends INCREASE for a change.

 

[DFWWeather]

Actually, it's a known proven fact that the 6Z and 18Z are just important as any other run. Now, no I wouldn't base a forecast purely on one run of any model, but to deny and throw out the trends since the 18z, 00z, 06z and now 12z today is pure ludicrous. Especially when you compare with UKMET, Euro, and GEM...all of which also has wintry precip for the Sunday night into Monday time frame. Not saying, this is going to happen for certain, but it's def. not something to be ignored as these trends INCREASE for a change.

 

 

I'm not denying the trends, but the other trend that is obvious is the warming at H85 level on all of the models you mentioned since last week. That has me extremely cautious on this event, especially since every winter event this winter has fizzled. Now if we can get this again tomorrow on the 0z and 12z runs and the ECMWF, I will start to believe we may have something here. It will really take surface temps in the mid 20s for this to pan out as a significant event. Right now, I don't think it looks quite that cold at least at DFW.

[ams30721us]

For East Texas, this is starting to look like a pretty Icy Monday. Check out how temps drop during the event here.

 

Sunday (Midnight)

Monday Morning:

Monday Midday:

Monday Afternoon:

[ams30721us]

12Z GEM still keeping precip around with that disturbance Monday.

 

[wxmx]

The fate of the 700-850mb temp profile layer depends on how the piece of energy being left behind in CA behaves. The further south it digs, the better chances of snow for the area around DFW. If it can get close to the CA/NV/AZ borders, the better the chances. It does appear that boundary/surface temps won't be a problem as the arctic surface high will be strong enough, although shallow, thanks to the h500 setup. Currently I think there will be ptype issues for most of the DFW area, with sleet/zr being the most probable precip outcome.

 

After that, there's strong consensus of a new cold wave, but details aren't clear yet...especially as there might be remaining energy from the aforementioned CA s/w and maybe more Pac energy on the way. H500 setup may be better for moisture and mid/upper level cold than the next one this Monday.

[bubba hotep]

Actually, it's a known proven fact that the 6Z and 18Z are just important as any other run. Now, no I wouldn't base a forecast purely on one run of any model, but to deny and throw out the trends since the 18z, 00z, 06z and now 12z today is pure ludicrous. Especially when you compare with UKMET, Euro, and GEM...all of which also has wintry precip for the Sunday night into Monday time frame. Not saying, this is going to happen for certain, but it's def. not something to be ignored as these trends INCREASE for a change.

I agree, verification scores don't really show any one run being better than the others over a significant period of time. That being said, I only noticed some minor changes in the 12z GFS for this weekend. However, there are significant changes with how the next system is handled.

[Srain]

The 2 meter temperature are about 2-4 'colder' for Sunday night into Monday via the 12Z GFS which raises an eyebrow. Also the 48 hour QPF is anywhere from .50 to near an inch during the Sunday afternoon to early Tuesday morning timeframe. Regarding the late week period when the upper trough finally approaches, there have been 'hints' of a Coastal trough developing which tends to make sense as the 5H low progresses Eastward and what we typically see with these positive tilted troughs.

[ams30721us]

Just for curious eyes....the GEM for the late week system is such a dream boat. LOL

[wxmx]

Evolution on the 12z Euro is similar to the GFS, but a tad colder... doesn't look half bad.

 

[vwgrrc]

Monday is starting to look like a big event, but still have many model runs to go. Could be similar to Dec '13 or March '14. Then another potential winter weather event on Thursday. Temps will be very cold all week with maybe a blip of a warm-up between the storms.

I'll be super thrill to have Dec 13 to replay again!

 

BUT, if I remember correctly, that event was so significant that was forecasted by NWS 4-5 days in ahead. The precip started on Thu afternoon, we had special wx statement on Monday, then advisory-watch-warning, steped up one level per day. This doesn't look like that event, at least no special statement at this far out.

[aggiegeog]

Here is a meteogram I came up with by modifying wxman57 from Storm2k's template for my home north of Tyler from the 12Z GFS. It appears that the models are coming into agreement on a significant sleet storm. This seems to show 1-2 in of sleet for me. Though it has lost the late week storm, but that is prob temporary.

 

[Srain]

I'm getting that vibe of what we experienced early last March when we received about an inch of freezing rain here in NW Harris County.

[aggiegeog]

I'll be super thrill to have Dec 13 to replay again!

 

BUT, if I remember correctly, that event was so significant that was forecasted by NWS 4-5 days in ahead. The precip started on Thu afternoon, we had special wx statement on Monday, then advisory-watch-warning, steped up one level per day. This doesn't look like that event, at least no special statement at this far out.

It is reminding me of last March at least for my area. I got a couple inches of sleet and lots of thunder and lightning from that storm. That was followed by extreme cold and flurries though that part does not seem to be in the cards on this event.

[bubba hotep]

It will be interesting to see what the different AFDs have to say this afternoon. Models seem to be stabilizing a bit for this first system but some of the finer details won't be resolved until this weekend. It wouldn't take big changes in the column temps to get the northern side more into snow and out of the sleet game.

[Quixotic1]

96 hours out isn't something to sneer at.  

[vwgrrc]

96 hours out isn't something to sneer at.  

What I'm really looking forward is Sat 12z, which should nail most of the game IMO.

[Roy]

Aggie, I found his post with his files....was it easy to modify to do what you did?

[ams30721us]

Just saw the 12z Euro. Its pretty cool to FINALLY (hope I didn't just jinx it) see perfect agreement among the main globals of a winter event less than 100 hours. out. The Euro is harder to breakdown and get full details on but at worse it's showing a widespread ice event Monday of freezing rain and depending on the depth of cold...up to several inches of sleet/snow west to east along I20 corridor. I agree, should be interesting to read afternoon AFD's.

[aggiegeog]

Aggie, I found his post with his files....was it easy to modify to do what you did?

It was not too bad. Took me a bit to figure out how to do the charts in Excel as I have not used it much in a good while. I just followed the instructions to get the data and selected the fields I wanted to use then I used his instructions though with my selected fields instead.

[DFWWeather]

Just saw the 12z Euro. Its pretty cool to FINALLY (hope I didn't just jinx it) see perfect agreement among the main globals of a winter event less than 100 hours. out. The Euro is harder to breakdown and get full details on but at worse it's showing a widespread ice event Monday of freezing rain and depending on the depth of cold...up to several inches of sleet/snow west to east along I20 corridor. I agree, should be interesting to read afternoon AFD's.

 

The 12z ECMWF is not cold enough at the surface for a significant winter storm at DFW. Raw model output shows surface temps are barely below freezing with -0.8°C the coldest (which is warmer than prior runs). H85 temps also warmed on this run. Temperatures must fall to at least 27°F for this to overcome the warm grounds. Though, QPF did increase on this run. It still looks very marginal to me and wouldn't be surprised if the afternoon AFD is very conservative this afternoon for the Metroplex counties.

 

Having said that, surrounding areas north and east of the Metroplex may get a decent event.

[vwgrrc]

The 12z ECMWF is not cold enough at the surface for a significant winter storm at DFW. Raw model output shows surface temps are barely below freezing with -0.8°C the coldest (which is warmer than prior runs). H85 temps also warmed on this run. Temperatures must fall to at least 27°F for this to overcome the warm grounds. Though, QPF did increase on this run. It still looks very marginal to me and wouldn't be surprised if the afternoon AFD is very conservative this afternoon.

Yes. Even on GFS, 12z holds most of 6z, it's showing a warning trend at least for dfw metro area. NOT good!