Texas Winter 2012-2013

[SaskatchewanScreamer]

:lol: You evil lot are enjoying this too much!

I'll turn ALL my fans on and will send the polar bears and wolves express to y'all!!!

Promises, promises ... I'm still waiting for said fans to really turn on.

and won't you be crying frozen tears if it does make it down to you.

you fools are playing/hoping/dreaming over something sooooooooooooo nasty that you will never ever be prepared for.

[SaskatchewanScreamer]

Now this is a very, very nice day here......I wonder what Houstonians would think of it.


Moose Jaw, SK

Current Weather 9:45 CST
Overcast

-8°C (18F)

Overcast

Feels Like : -16C (3 F)
Wind : N 26 km/h
Wind gusts : 45 km/h

Humidity : 82%
Pressure : 102 kPa
Visibility : 16 km

[Tireman4]

You might just want to start burning those treasured books of yours Tireman.

Oh dear. Such language. Oh my.

[Ntxw]

12z GFS does give a little wintry precip to San Antonio and southwest of there. Take it with a grain of salt, this freaking model is totally a pain in the rear to follow with all the back and forth. Essentially every run for the past 3 days has been different.

[Tireman4]

Now this is a very, very nice day here......I wonder what Houstonians would think of it.


Moose Jaw, SK

Current Weather 9:45 CST
Overcast

-8°C

Overcast

Feels Like : -16
Wind : N 26 km/h
Wind gusts : 45 km/h

Humidity : 82%
Pressure : 102 kPa
Visibility : 16 km

I do not know. Let us go to tale of the tape....


Humble, Texas

Overcast

41°F

5°C

Humidity 51%
Wind Speed E 10 mph
Barometer 30.48 in (1032.3 mb)
Dewpoint 24°F (-4°C)
Visibility 10.00 mi
Wind Chill 35°F (2°C)

[SaskatchewanScreamer]

I give......however if record breaking cold makes it down there you will hear laughter coming from your North.

[Portastorm]

12z GFS does give a little wintry precip to San Antonio and southwest of there. Take it with a grain of salt, this freaking model is totally a pain in the rear to follow with all the back and forth. Essentially every run for the past 3 days has been different.

More importantly, did you see WHY it is showing that? Yes, it cuts off a 500mb low like the Euro solution. So now, we're back to where we were yesterday and that is that a 12z GFS op run is coming to the Euro's consistent solution.

I concur with your thoughts that we're bound to see more changes in these model runs. I'll be curious to see if the crazy Canadian (no offense, Sask Screamer) comes back to the Euro solution now.

[Portastorm]

To demonstrate how clueless the GFS operational runs are right now ... below is the model's depiction of the weather over the USA at the 500mb level as of 12z Jan. 4th. The first map is what the 0z run showed ... the second is what the recently issued 12z showed. No consistency whatsoever. The GFS is really struggling with this split-flow pattern to be sure. It clearly is struggling with how to handle the southern stream energy.



Uploaded with ImageShack.us



Uploaded with ImageShack.us

[Ntxw]

Canadian does not come around. But we haven't talked much about the UKMET (12z). It has not changed and has been sticking with the euro about the coastal low and lower heights. But we aren't in the realm of seeing precip yet as that only goes out to 72 hours for this model.

[Portastorm]

And ... this just in ... perhaps a little surprise today for folks in south central Texas? ... want a little sleet mixed with that light rain?! Sure!

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
950 AM CST SUN DEC 30 2012

.UPDATE...
INCREASED SKY COVER AND LOWERED MAX TEMPS A DEGREE OR TWO AT A FEW
LOCATIONS FOR THIS AFTERNOON. ALSO BROUGHT LIGHT RAIN OR SPRINKLES
FURTHER EAST ACROSS THE ENTIRE CWA FOR THE AFTERNOON AS PCPN WAS
ADVANCING A LITTLE FASTER NEWD THAN EXPECTED. QPF AMOUNTS WILL BE
VERY LIGHT WITH MAINLY TRACE AMOUNTS TO A FEW HUNDREDTHS. DRT
SOUNDING SHOWS A FAIRLY WARM LAYER AT 7-10K FEET...HOWEVER THIS
LAYER IS ALSO VERY DRY...SO WITH EVAPATIVE COOLING...SOME LIGHT
SLEET COULD BE MIXED IN WITH THE LIGHT RAIN TODAY

[Stormlover2012]

atleast cmc is cold!!!

[Portastorm]

atleast cmc is cold!!!

Take a look at the 500mb level differences between the 0z CMC and the 12z CMC. You will notice that the more recent model run, like the trend in the 12z GFS as compared to its 0z run, shows a more pronounced and cutoff upper low over northern Mexico. What happens there is going to be HUGE in terms of whether or not parts of Texas see winter weather next week. But the CMC trend is something to take note of.

[Ntxw]

Canadian set up isn't that bad actually. Unlike the other models it's been trying to hang the SW system too long and no surface reflection happens but overall those features can be ironed out.

[BrokenGlassRepublicn]

For a lurker, will somebody explain to me in layman's terms about 500mb and 800mb?

[SaskatchewanScreamer]

BTW I do wish you fellows get rain however I still think y'all are nuts wanting really cold temps. We are/will be breaking records up North.....down there extreme cold records would be devastating to both your pipes and crops (I do like Texas grapefruit and oranges).

[Rgv20]

Its looking more and more likely that we are going to get some London weather here in the RGV! Temperatures not getting out of the 40s and drizzle come Wednesday and Thursday..

Be kind to the RGV Screamer our Citrus and Palm Trees can't take too much cold

[Portastorm]

For a lurker, will somebody explain to me in layman's terms about 500mb and 800mb?

Here is a good primer in layman's terms. Hope it is helpful.

http://www.accuweather.com/en/weather-blogs/weathermatrix/how-to-read-computer-forecast-model-maps/19488

[Ntxw]

To add to Porta's post

***
Constant Pressure Surface- Most analysis and model images are shown using a pressure surface. The most common are the 1000 mb, 850 mb, 700 mb, 500 mb, and 300 mb surfaces. Every location on the image has the same pressure, however, heights will vary (thus the contouring of height contours). Below is a listing of pressure surfaces and their approximate height above zero geopotential meters.

1000 mb-- near surface <- You live near this
850 mb-- 1,500 meters (5,000 feet) <- West Texas people
700 mb-- 3,100 meters (10,000 feet) <- Moisture transport often happens here (clouds)
500 mb-- 5,500 meters (18,000 feet) <-Wind vortices, the stuff that drives storms and high pressure
300 mb-- 9,300 meters (30,000 feet) <-Jet streams

[Portastorm]

To add to Porta's post

***
Constant Pressure Surface- Most analysis and model images are shown using a pressure surface. The most common are the 1000 mb, 850 mb, 700 mb, 500 mb, and 300 mb surfaces. Every location on the image has the same pressure, however, heights will vary (thus the contouring of height contours). Below is a listing of pressure surfaces and their approximate height above zero geopotential meters.

1000 mb-- near surface <- You live near this
850 mb-- 1,500 meters (5,000 feet) <- West Texas people
700 mb-- 3,100 meters (10,000 feet) <- Moisture transport often happens here (clouds)
500 mb-- 5,500 meters (18,000 feet) <-Wind vortices, the stuff that drives storms and high pressure
300 mb-- 9,300 meters (30,000 feet) <-Jet streams

Excellent post and primer! Folks should keep this handy.

[Ntxw]

Euro taketh, maybe some wintry stuff along the upper and middle RGV