Winter 2010-11 for the Southern Plains

[Extremeweatherguy]

Tonight's 0z NAM is not promising at the least. It takes the storm further north after entering California before diving southeast. This would choke it from moisture (as seen by models for some time). My question is what will the plume of moisture just south of the system west of the Baja do...

Temps and precip this run favors eastern Oklahoma. But surface profiles seem warm, hence it shows no accumulating snow.

Yeah, I noticed the warm profiles on the NAM. Looks warmer than the GFS. Still enough to probably see some snowflakes mix in, but as you pointed out if this scenario actually plays out, then accumulations of any kind will be hard to come by.

The biggest difference in the NAM between today and previous days is the wind direction over Oklahoma on Tuesday. Previous days' runs had us mostly in a N or NNE wind direction for most of the day, while today's runs show the winds becoming SE/E for the first half of the day (before eventually shifting back toward the NE later). This period of more southerly-oriented winds would allow for some warmer low-level air to be introduced into the region ahead of the precipitation.

Last night's 00z NAM skew-T for OKC (valid 9pm Tues.): http://www.twisterdata.com/data/tmp/scr ... .5000W.png

VS.

Today's 00z NAM skew-T for OKC (valid 9pm Tues.): http://www.twisterdata.com/data/tmp/scr ... .5000W.png

[frigidice77]

What happens to the system after it moves through the southern plains? Does it dissipate or what?

[Ntxw]

What happens to the system after it moves through the southern plains? Does it dissipate or what?

What happens in the southern plains, will likely show what will happen in the south. A more robust storm in the soplains would give more 'surprises' down the road.

Not always the case, rule of thumb for me generally if there is snow/freezing precip in the southern plains there's a good chance someone in the mid-south to deep south would see it also. However, models dive it into the gulf and cutting off moisture except maybe some rain or sprinkles into central Florida.

[Extremeweatherguy]

No big surprises from the 00z GFS tonight. Looks about the same as it has most of the day; showing spits of light QPF values in Oklahoma throughout the day on Tuesday and into Tuesday night, but no measurable precipitation for most. Mainly just an increase in clouds and a few scattered sprinkles or snow flurries if this runs proves correct. One or two places could get lucky and see a quick dusting of snow out of this ( http://www.twisterdata.com/data/models/ ... URFACE.png ), but these places look to be few and far between.


Of more interest is what the GFS is showing in the slightly longer range. It appears as though the model is starting to trend toward the ECMWF's idea of a very cold shot of air sweeping down the plains in just under a week. The 00z run is also showing some wrap around snow showers that may be of interest to us by next weekend, but after suffering through watching the current system for the last week, I think I will wait a few days longer before I get too excited about that possibility. Still looking very interesting though..

138 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_138l.gif
144 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_144l.gif
150 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_150l.gif
156 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_156l.gif
162 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_162l.gif
168 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_168l.gif
174 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_174l.gif
180 hrs: http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_180l.gif

[Ntxw]

Noticed that too. Just for giggles, early thoughts from the models put that potential storm as an I-40 north line of demarcation. Classic panhandle hooker.

[Extremeweatherguy]

00z ECMWF QPF output for Tuesday evening:

0.04" of liquid-equivalent precipitation in OKC and 0.03" of liquid-equivalent precipitation in DFW.

Not much, but still more than the 00z GFS is showing..

[Extremeweatherguy]

12z ECMWF QPF output for Tuesday evening:

OKC: 0.05"
OUN: 0.06"
DFW: 0.01"

[Kelarie]

Do you know how far east that is showing? I am in Texarkana and they have us at a 20% chance tomorrow night of rain/snow mix. Thanks.

[Ntxw]

Do you know how far east that is showing? I am in Texarkana and they have us at a 20% chance tomorrow night of rain/snow mix. Thanks.

Consensus has very very very small qpf for eastern Oklahoma, Western Arkansas, and into the Arklatex region. So it looks like you stand a chance at it. Though 20% might be just a formal number. I'd give it less than 10% if you ask me personally.

Edit: The lower levels will be dry, and above freezing so I expect some of the qpf will be towards evaporative cooling and to moisten up.

[Extremeweatherguy]

Do you know how far east that is showing? I am in Texarkana and they have us at a 20% chance tomorrow night of rain/snow mix. Thanks.

The 12z ECMWF is showing a QPF value of 0.05" for Texarkana tomorrow evening.

Just because it shows this though, doesn't mean it'll actually happen. Instead, I would interpret this as meaning a good chance of a cloudy period and a low chance of scattered light showers (either rain or snow). A 20% chance of precipitation is a good forecast to me right now, but this may need to be trended up/down tomorrow as we see how things are actually playing out with the radar imagery and surface reports.

[Kelarie]

Thanks y'all for the information!

[Ntxw]

18z NAM hang in there folks. Small glimmer of hope. I'm still waiting to see what comes of the Baja 'disturbance/energy'. SE Texas should have something to chatter about.

Close enough and potentially heavy enough to monitor.

[TwisterFanatic]

Weather Channel going on the high side with the chance of snow tomorrow night. They're going with 60%

[Extremeweatherguy]

Latest thoughts from the OUN NWS office for Oklahoma...



My point-and-click forecast currently calls for a 20% chance of a rain/snow mix tomorrow and tomorrow night, areas in north-central Oklahoma have a 40% chance.

If the trend of the recent models (slightly higher, more widespread QPF values) continues though, then I wouldn't be surprised to see the precip. chances raised a little bit tomorrow; especially if radar and surface obs are looking decent by the afternoon.

[Ntxw]

An overall look to track the monster currently in the rockies.

[Extremeweatherguy]

We are starting to get close to the HRRR (High Resolution Rapid Refresh) model timeframe, which goes out 12 hours. By later tonight, the HRRR should be producing reflectivity products, precipitation-type maps, snow accumulation data, etc that may be of help in forecasting for tomorrow afternoon and evening. The HRRR is much more detailed than the GFS and NAM, and can be extremely helpful with precipitation events...

http://rapidrefresh.noaa.gov/hrrrconus/

The HRRR also updates every hour, which is nice.

[Ntxw]

0z NAM has precip over the Arklatex, but the lower levels are warm, hence has no accumulating snow.

[iorange55]

0z NAM has precip over the Arklatex, but the lower levels are warm, hence has no accumulating snow.

Your icon is making me drool.

[Ntxw]

Your icon is making me drool.

Lol, it may be the only 'snow' radar image we'll see this winter, so I used it to cope!

Of curiosity, the RUC tonight shows the low closing off in Kansas . Still very dry atmosphere though...

[iorange55]

Your icon is making me drool.

Lol, it may be the only 'snow' radar image we'll see this winter, so I used it to cope!

Don't talk like that.