Texas Winter 2013-2014

[aggiecutter]

There are winter weather advisories for tonight and tomorrow just one county to my north.

[Kelarie]

There are winter weather advisories for tonight and tomorrow just one county to my north.

Maybe Texarkana can sneak in on the fun.

[dhweather]

Downright depressing. 18Z GFS for DFW


http://img716.imageshack.us/img716/9646/f5im.png

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This may be a total wishcast, but I'm going to chalk up the lack of moisture this weekend to the GFS habit of losing these storms in the 3-5 day range.

Unfortunately, cold air brings dry air with it. One of the many things that make wintry precip so hard to get down here.

[Ntxw]

As promised here are the precip stats since 2007 (since the flip of the PDO to negative and beginning of multi-year drought).

Annual average rainfall for DFW: 36.14 inches

6 Years were taken to accound between 2008 and 2013

The average annual rainfall for that period is 31.12 inches. The lowest year was 2011 with 25.88 inches, highest was 40.89 during the 2009 one and only El Nino during the period.

In comparison the early 1950s averaged 22.34 inches a year. Lowest year being 1956 with 18.55 inches. HIghest being 1955 at 25.16, thus making the highest yearly rainfall of this period lower than the lowest in the current stretch.

I have to dig a little more for the 30s but they too were much lower than the current one as well as the early 1900s was too was drier. A good comparison to the current drought would be the -PDO year of the late 70s which in the same length of time since the flip averaged 31.39 inches for DFW.

Moral of the story is the current stretch of drought is not fun, but much of it is more perception than reality due to the population growth. I also read several articles back in 2011 that Texas was under desertification which is a complete myth as a period of dry years does not turn you into a desert. Wind shift and geography does in a span of hundreds of years (where rainfall averages is less than 10 inches permanently). This is driven by the cyclical nature of the Pacific Ocean and ENSO.

This is data for DFW and not the rest of Texas, that would take a very lengthy research project that perhaps someone might want to dig into

[aggiecutter]

The 0z NAM lays down around an 1" of snow for the Texarkana area on Friday.

[TheProfessor]

We have already reached are forecasted low (36) could it go down even more?

[KeriCarter]

The 0z NAM lays down around an 1" of snow for the Texarkana area on Friday.

Thank you for that info. I know not to look for it until I see it, but even the possibility is exciting. For the kiddos, of course.

[Ntxw]

Wow! 0z GFS flips a different direction and shreds our weekend storm, eventually sending out what's left to...Kansas!

[orangeblood]

Wow! 0z GFS flips a different direction and shreds our weekend storm, eventually sending out what's left to...Kansas!

Yikes! Completely blows up the system and ejects energy out in pieces across central plains....don't think I've ever seen a model flip to that extreme - any issues with initialization tonight ?

[Ntxw]

Wow! 0z GFS flips a different direction and shreds our weekend storm, eventually sending out what's left to...Kansas!

Yikes! Completely blows up the system and ejects energy out in pieces across central plains....don't think I've ever seen a model flip to that extreme - any issues with initialization tonight ?

It's loco, you don't just radically change something like that. I haven't seen any other model show that kind of solution yet so we'll see. My guess it's on something and just likes to visit Kansas often.

[Lagreeneyes03]

Downright depressing. 18Z GFS for DFW


http://img716.imageshack.us/img716/9646/f5im.png

Uploaded with ImageShack.us

This may be a total wishcast, but I'm going to chalk up the lack of moisture this weekend to the GFS habit of losing these storms in the 3-5 day range.

Unfortunately, cold air brings dry air with it. One of the many things that make wintry precip so hard to get down here.

What I don't understand if the cold air is so dry, how does the central US and North get all that snow with "dry" air?

[Meteorcane]

What I don't understand if the cold air is so dry, how does the central US and North get all that snow with "dry" air?

a couple reasons
1.) There are strong sources of lift that can cool even dry air to condensation, these include topography (in the mountain west). mechanical lifting (mid-latitude cyclones and their associated fronts generally track further north.
2.) Decrease of solar radiation with latitude (in winter) causes generally cooler "equilibrium" temperatures, this sometimes allows temperatures to remain below freezing even when warmer moist air is advected from the GOM, Gulf stream, etc.

Here in the south to get temperatures below freezing we often need arctic highs, which generally come with very dry continental air. Occasionally we can get sufficient lift to overcome that dryness (such as being in a favorable(downstream) position of a trough) this can allow us to get some wintry precip.

[orangeblood]

I think it's a good time to test out the SREF members for Thursday's system.....today's 21Z run for DFW has a mean temp of 32 for the high on Thursday, 2/3rds of the members showing snow with half of them with 1-4 inches of the white stuff. 6 out of 21 members have Austin with Winter Precip on Thursday as well. It seems to be have been an atrocious set of models lately but I'll give it one more shot before completely discarding

[orangeblood]

Wow, tonight's models have almost completely lost the system they've been showing for several days now but our Crazy Canadian Uncle still found a way to pull a rabbit out his hat for late this week.....

[Ntxw]

I think it's a good time to test out the SREF members for Thursday's system.....today's 21Z run for DFW has a mean temp of 32 for the high on Thursday, 2/3rds of the members showing snow with half of them with 1-4 inches of the white stuff. 6 out of 21 members have Austin with Winter Precip on Thursday as well. It seems to be have been an atrocious set of models lately but I'll give it one more shot before completely discarding

The Ukmet has suggested light snow for areas from I-20 to the Red River on northward for Friday for the past 2 runs.

[Ntxw]

Wow, tonight's models have almost completely lost the system they've been showing for several days now but our Crazy Canadian Uncle still found a way to pull a rabbit out his hat for late this week.....

it seems the models tonight are trying to bring back, I say this with hesitation, the friday system that they seemingly have lost. At 5h on the euro it looks decent. The following system they have shifted north. If the two pieces work together I wonder if we can get a deeper system? It seems how the two interact will effect the other. If the first is stronger the second is weaker vice versa is what it seems on the guidance.

But there are a lot of pieces so I may be confused...

[Kelarie]

From Shreveport NWS

Winter Weather Advisory
ARZ050-051-059>061-070>073-OKZ077-TXZ097-041800-
/O.CON.KSHV.WW.Y.0005.000000T0000Z-140204T1800Z/
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
COLUMBIA-UNION AR-MCCURTAIN-BOWIE-
INCLUDING THE CITIES OF...DE QUEEN...NASHVILLE...ASHDOWN...HOPE...
PRESCOTT...TEXARKANA...LEWISVILLE...MAGNOLIA...EL DORADO...IDABEL
503 AM CST TUE FEB 4 2014

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON CST
TODAY...

* EVENT...LIGHT RAIN WILL CONTINUE TO EXPAND RAPIDLY NORTH AND
EAST ACROSS THE ADVISORY AREA THIS MORNING. TEMPERATURES ARE
CURRENTLY AT OR JUST BELOW FREEZING AND WITH TEMPERATURES NOT
EXPECTED TO CLIMB ABOVE FREEZING UNTIL MID TO LATE MORNING...
SLIGHT ICE ACCUMULATIONS WILL BE POSSIBLE. ICE ACCUMULATION
WILL BE MAINLY LESS THAN ONE TENTH OF AN INCH.

* TIMING...THROUGH MID TO LATE MORNING.

* IMPACT...TRAVEL MAY BECOME HAZARDOUS ON ELEVATED ROADS AND
BRIDGES THIS MORNING DUE TO ICING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF LIGHT FREEZING
RAIN...COULD CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR SLIPPERY
BRIDGES AND OVERPASSES...LIMITED VISIBILITIES...AND USE CAUTION
WHILE DRIVING.

[WeatherGuesser]

Watching this thread for a while shows that people seem to focus too much on long range models. I'm not sure what most people consider a verification or a bust, but I don't see much verification.

A couple of weeks back, people were posting models showing record cold and snowfall from TX to the northeast states for early February. Now that we're in that time period, forecasts are only showing moderate cold and average precip, nothing extraordinary at all.

I still maintain that any forecast beyond 72-96 hours is untrustworthy. It may hold true, but things can change too easily.

Crikey, sometimes even the 24 hour forecast isn't completely accurate.

[wxman22]

Watching this thread for a while shows that people seem to focus too much on long range models. I'm not sure what most people consider a verification or a bust, but I don't see much verification.

A couple of weeks back, people were posting models showing record cold and snowfall from TX to the northeast states for early February. Now that we're in that time period, forecasts are only showing moderate cold and average precip, nothing extraordinary at all.

I still maintain that any forecast beyond 72-96 hours is untrustworthy. It may hold true, but things can change too easily.

Crikey, sometimes even the 24 hour forecast isn't completely accurate.

That may be true but thats what makes it fun many of us know the models are usually pulling our legs when it comes to the long range forecast, but its the possibility that they may be on to something that actually comes into fruition that makes it fun, cause sometimes long range models
DO verify.

[wxman57]

There's a big difference between model forecasts 2 weeks out vs. 2 days out. From 2-3 days before an event, model trends will provide good insight into what will happen. Sometimes, though, it's just a matter of a degree or two at the surface or aloft that makes all the difference. In such cases, models are less useful even from a day out. The problem I see in the D-FW area is lack of moisture Thu/Fri. Model soundings indicate an airmass well below freezing from the surface up, but quite dry air aloft.