Texas Winter 2013-2014

[gpsnowman]

Biggest flakes of the day falling now at a pretty good clip! Moderate now on the tail end of the precip.
Edit: These flakes are huge and coming down fast!! Too bad the end is near for this round. Gorgeous to witness nature like this.

[SouthernMet]

The 12Z Euro shows light wintry precip tomorrow with incoming shortwave across north Texas. It's light and brief. It's something though

north texas needs to watch the HRRR later tonight to see what if any impact tomorrow's shortwave will bring, that adds insult to injury.

[TheProfessor]

There is just a little bit of snow melting, I don't know how because it is below 20 degrees here and it is still snowing.

This is still the answer.

There is just a little bit of snow melting, I don't know how because it is below 20 degrees here and it is still snowing.

Incoming solar radiation from the sun.

No sorry the site randomly reposted my statement for some reason, I don't know why.

[aggiecutter]

A couple weeks ago some on this forum were wondering why it was warmer in east and southeast Texas as compared to the surrounding regions. One possible cause that I mentioned was the damning of the shallow cold air against the Quachita Mountains in West-Central Arkansas and SE Oklahoma. This phenomenon has more impact in the Ark-La-Tex region, but there are downstream implications.

Another possible cause is the Ozark down slope thermal ridge effect that is mentioned in a tweet by JB below:
"Ozark downslope thermal ridge on nne wind from se ark to south Texla area
Classic pic.twitter.com/jUBBX00A6Z"

[GRAYSONCO.WX]

A couple weeks ago some on this forum were wondering why it was warmer in east and southeast Texas as compared to the surrounding regions. One possible cause that I mentioned was the damning of the shallow cold air against the Quachita Mountains in West-Central Arkansas and SE Oklahoma. This phenomenon has more impact in the Ark-La-Tex region, but there are downstream implications.

Another possible cause is the Ozark down slope thermal ridge effect that is mentioned in a tweet by JB below:
"Ozark downslope thermal ridge on nne wind from se ark to south Texla area
Classic pic.twitter.com/jUBBX00A6Z"

Yeah, shallow, dense arctic airmasses get caught up along the mountains in southern Oklahoma sometimes.

[dhweather]

Looks like one more decent band will come by before the system moves out, we have about 3/4 of an inch in Heath.

[iorange55]

Looks like the last band is hitting my area right now, it probably has the biggest snowflakes with it. I would have preferred to see 3 or 4 inches on the ground, but this sure was pretty to look at it.

[dhweather]

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1152 AM CST THU FEB 6 2014

.AVIATION...
/18Z TAFS/

TIMING THE ENDING OF LIGHT SNOW AND AND IFR RESTRICTIONS EXPECTED
TO BE THE MAIN CHALLENGE THROUGH 21Z THIS AFTERNOON...THEN CIGS
AND ANY LIGHT WINTER PRECIP NEAR WACO BECOME A CHALLENGE AFTER 12Z
FRIDAY.

BANDS OF LIGHT SNOW WITH MVFR CIGS/IFR VSBYS WILL BE THE CHALLENGE
THROUGH MID AFTERNOON. RADAR IN CLEAR AIR MODE SHOWS A BACK EDGE
COMING INTO BRIDGEPORT...MINERAL WELLS AND GRANBURY ATTM. HAVE
KEPT PESSIMISTIC CONDITIONS ACROSS MUCH OF DFW THROUGH 19Z...WITH
IMPROVEMENT TO P6SM/FLURRIES THROUGH 22Z WITH MVFR CIGS CONTINUING.
LOWER VFR CIGS SHOULD PREVAIL TONIGHT BEFORE THE NEXT SYSTEM APPROACHES
FROM THE WEST AFTER 12Z FRI. THERE ARE PLENTY OF UNCERTAINTIES ON
MOISTURE AND ANY LIGHT WINTER PRECIP ACROSS DFW AT THIS TIME. AS SUCH...
WILL ONLY INTRODUCE MVFR CIGS BACK INTO THE FORECAST FOR NOW
FRIDAY MORNING.

ACROSS WACO...VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT WITH A
FEW SNOW FLURRIES POSSIBLE THROUGH 21Z...BUT NOT ENOUGH FOR ANY VSBY
RESTRICTIONS BELOW VFR. WILL BRING MVFR AND VERY LIGHT WINTRY MIX
BACK INTO THE TAF BY 15Z AND AFTER FRIDAY WITH PLENTY OF
UNCERTAINTY AT HAND.

NORTH WINDS 10 KTS SHOULD CONTINUE TO WEAKEN AND VEER NORTHEAST OR
EAST AROUND 5-7 KTS OVERNIGHT. LIGHT SOUTHEAST FLOW AROUND 5 KTS
RETURNS EARLY FRIDAY.

[dhweather]

12Z GFS

[iorange55]

Oh, geez. If it's going to be falling as rain, I sure hope the temp stays above 32. That would just be miserable if most of that was freezing rain.

[dhweather]

:uarrow: Oh, geez. If it's going to be falling as rain, I sure hope the temp stays above 32. That would just be miserable if most of that was freezing rain.

No kidding!


Big fat fluffy flakes falling now, so I guess it's almost over. About an inch total accumulation in Heath.

[BigB0882]

Why do you get really big flakes on the tail end of a snow storm? I remember that happening here in Baton Rouge in 2008. The flakes were huge, like dollar coin size and it lasted about 5-10 minutes and then stopped completely.

[Meteorcane]

Why do you get really big flakes on the tail end of a snow storm? I remember that happening here in Baton Rouge in 2008. The flakes were huge, like dollar coin size and it lasted about 5-10 minutes and then stopped completely.

Sadly despite the fact that I am currently perusing my masters in meteorology with an emphasis on cloud microphysics, I can not give you a satisfactory answer. Generally larger snowflakes tend to be indicative of a warmer environment as the probability of two ice crystals aggregating is complexly related to their shape and temperature (with higher temperatures allowing for more "stickiness"), also dendrites and needles tend to aggregate easier than plates and columns which tend to "bounce off" more often. One possible explanation is that the environment is worsening (i.e. becoming drier/less saturated) causing smaller flakes to sublimate. Another explanation is that certain crystal habits actually become more aerodynamic with size (unlike rain or hail in which fall speed is proportional to particle diameter), perhaps certain larger crystals drift/fall longer than smaller ones.

Ice-phase microphysics is really hard, maybe its no surprise I prefer to study tropical precipitation , where the density of precip is known, the shape can be modeled pretty accurately etc

[BrokenGlassRepublicn]

12Z GFS

http://img163.imageshack.us/img163/8851/igyy.png

Interesting intersection of dewpoints and surface temps overnight on Friday.

[Tejas89]

They just played the instrumental Christmas Song (jack frost nipping at your nose, etc..) on WRR 101... Announcer apologized afterwards, saying it should have been "Walking In A Winter Wonderland".

[Ntxw]

43rd freeze, 44th cometh. Officially each month of DJF for DFW have recorded teens

[wxman57]

12Z GFS

http://img163.imageshack.us/img163/8851/igyy.png

Interesting intersection of dewpoints and surface temps overnight on Friday.

That happens most mornings under radiative cooling. Relative humidity is quite frequently around 100% near sunrise.

[orangeblood]

Why do you get really big flakes on the tail end of a snow storm? I remember that happening here in Baton Rouge in 2008. The flakes were huge, like dollar coin size and it lasted about 5-10 minutes and then stopped completely.

Sadly despite the fact that I am currently perusing my masters in meteorology with an emphasis on cloud microphysics, I can not give you a satisfactory answer. Generally larger snowflakes tend to be indicative of a warmer environment as the probability of two ice crystals aggregating is complexly related to their shape and temperature (with higher temperatures allowing for more "stickiness"), also dendrites and needles tend to aggregate easier than plates and columns which tend to "bounce off" more often. One possible explanation is that the environment is worsening (i.e. becoming drier/less saturated) causing smaller flakes to sublimate. Another explanation is that certain crystal habits actually become more aerodynamic with size (unlike rain or hail in which fall speed is proportional to particle diameter), perhaps certain larger crystals drift/fall longer than smaller ones.

Ice-phase microphysics is really hard, maybe its no surprise I prefer to look study precipitation , where the density of precip is known, the shape can be modeled pretty accurately etc

Thanks for the input Meteorcane....snow science is a fascinating and very humbling field of study. Today's storm was another humbling day for the Pro mets in the metroplex I'm sure. But it needs to reiterated again....as Ntxw has mentioned several times, when you have this type setup in this part of the country - where temps are in the low 20's to upper teens (doesn't happen too often) and this type of fairly rigorous shortwave moving through - more often than not, these systems find a way to squeeze out any moisture in the column. The alarm went off for me yesterday as the RUC skew T's starting rolling in - an almost entirely saturated column from the surface up through 18,000 feet with a thick dendritic growth zone and snow ratios probably approaching 15 - 20 to 1. Well sure enough, the short range models and even last nights Euro had precip in DFW greater than 0.05 inch, and at that point this mornings storm shouldn't have been too surprising. The American models were terrible in picking up the location of enhanced lift - had most towards wichita falls into southern Oklahoma when in fact it was much further south. On top of that, they insisted on a dry layer around 800-850 mb remaining intact the entire event and never gave into the saturated column the RUC model picked up on.

Tomorrows system appears like it has another even thicker column of dry air to overcome but still has a thick dendritic growth zone intact around the 600-500 mb level and precipitable water values on the increase again later tonight, it'll be interesting to see if the snow can overcome the really dry layer at around 850-700 mb. Temps will be a little warmer so anything that does fall will have much lower snow ratios but ground/road temps will remain below freezing so anything that does fall will freeze on contact....another tough forecast for the FTW NWS office for tomorrow and then probably an even tougher one on Tuesday, those guys aren't going to get much sleep over the next week that's for sure. Exciting times for Texas winter weather lovers!!!


The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

[Meteorcane]

Thanks for the input Meteorcane....snow science is a fascinating and very humbling field of study. Today's storm was another humbling day for the Pro mets in the metroplex I'm sure. But it needs to reiterated again....as Ntxw has mentioned several times, when you have this type setup in this part of the country - where temps are in the low 20's to upper teens (doesn't happen too often) and this type of fairly rigorous shortwave moving through - more often than not, these systems find a way to squeeze out any moisture in the column. The alarm went off for me yesterday as the RUC skew T's starting rolling in - an almost entirely saturated column from the surface up through 18,000 feet with a thick dendritic growth zone and snow ratios probably approaching 15 - 20 to 1. Well sure enough, the short range models and even last nights Euro had precip in DFW greater than 0.05 inch, and at that point this mornings storm shouldn't have been too surprising. The American models were terrible in picking up the location of enhanced lift - had most towards wichita falls into southern Oklahoma when in fact it was much further south. On top of that, they insisted on a dry layer around 800-850 mb remaining intact the entire event and never gave into the saturated column the RUC model picked up on.

Tomorrows system appears like it has another even thicker column of dry air to overcome but still has a thick dendritic growth zone intact around the 600-500 mb level and precipitable water values on the increase again later tonight, it'll be interesting to see if the snow can overcome the really dry layer at around 850-700 mb. Temps will be a little warmer so anything that does fall will have much lower snow ratios but ground/road temps will remain below freezing so anything that does fall will freeze on contact....another tough forecast for the FTW NWS office for tomorrow and then probably an even tougher one on Tuesday, those guys aren't going to get much sleep over the next week that's for sure. Exciting times for Texas winter weather lovers!!!


The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

Yep we discussed that briefly last night in the OK thread, about how the very high snow-liquid ratios (for this part of the country) would probably catch some people off guard who typically look at model QPF and quickly apply a 10:1 ratio. There used to be a site, that looked at model temperature and wind profiles (which has some effect on crystal density) and gave a more precise S-L ratio forecast, but I can't seem to find it anymore. Anyway I for one think tuesday has the potential to be a significant event for someone, the traditional synoptic vertical motion diagnostics all point to an area of enhanced lift somewhere in the North TX, OK, southern Kansas area. Moisture should not be an issue either, main issues right now are both track and borderline thermal profiles.

[orangeblood]

DGEX, JMA and GFS models are the most aggressive with Tuesday's storm....bringing in colder temps as heaviest precip is moving through.

DGEX has a major storm breaking out next week from Texas to the Carolina's...check out some of these snow totals (for entertainment purposes only), crazy sleet storm breaking out Tuesday morning.....






The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.