Texas Winter 2018-2019

[Quixotic]

Merry Christmas to this best discussion board in the land!

The first few days of 2019 are looking very very interesting and with the Potential Strat PV split and crazy looking MJO, the rest of winter is looking even better

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/diagram_40days_forecast_GEFS_member.gif


Hope everyone has a great Holiday!

That amplitude in those zones says snow is a lock.

[Cpv17]

The models are in crazy mode.

This looked nothing like this yesterday.

https://www.esrl.noaa.gov/psd/forecasts/reforecast2/teleconn/images/4indices.png

I don’t like the look of that much.

[ThunderSleetDreams]

The models are in crazy mode.

This looked nothing like this yesterday.

https://www.esrl.noaa.gov/psd/forecasts/reforecast2/teleconn/images/4indices.png

I don’t like the look of that much.

My point is that it doesn’t look the same run to run. If that MJO forecast kicks in, we are guaranteed cold and storms.

[bubba hotep]

The EPS propagates the MJO faster and at a lower amp than the GEFS.



In +ENSO January the analogs show a pretty big difference between high amp P6 and lower amp P8

P6 high amp Surface Temp Anomalies



vs P8 lower amp Surface Temp Anomalies

[rwfromkansas]

Man, I hope it gets cold. Come on man. Even going home to KS it will just rain. The cold keeps getting pushed back.

[TheAustinMan]

Here's what the extended HRRR 00z run had in store for Texas, valid at 9 PM tomorrow. Shaded areas denote regions of strong updraft helicity, or where the model sees rotation. While a lot of the ingredients for a severe event are there, what shakes out in the end is pretty conditional, a la only a few switches need to be flipped for the severe potential to decrease markedly. That also means only a few switches need to be flipped for the potential to greatly increase as well.

NWS FWD put out another great discussion this evening, and noted this succinctly:

"Although raw model reflectivity may show a scary forecast radar setup across Central Texas in the afternoon, most of that convection will likely be elevated, posing mainly a hail threat, followed by damaging winds. If a storm is able to gain enough surface based instability, the strong near surface wind shear would imply a higher threat for tornado development."

Still, an elevated thunderstorm is still a thunderstorm, and thunderstorms are dangerous. The main limiter is low instability in the low-levels of the atmosphere. You can see this very clearly on the 00z sounding from Dallas/Fort Worth (30 kB, Storm Prediction Center) as the warm cap that sticks out at about 800 mb. Aside from that, MUCAPE is pretty high, along with shear and mid-level lapse rates. According to the models, it will likely be cloudy for much of East Texas throughout the day tomorrow, limiting daytime heating, but the cyclonic flow around the developing low will probably help to advect some warmer Gulf/Mexican air from the south towards Central and South Texas.

Severe weather notwithstanding, there's a risk for flooding, particularly in the Metroplex and East Texas. Precipitable water values will be around 1.5", and NWS FWD notes widespread 1-3" totals with localized 4"+ which could lead to flash flooding from both a combination of showers ahead of the main modeled line and the squall line itself. WPC QPF 1-3 day totals indicate ~2" for Austin, ~1" for San Antonio, ~1.5" for the Metroplex, and ~2" for Houston. Keep in mind these are forecast areal averages over a 400 km^2 region.

292 KB. Source: Pivotal Weather

[Brent]

Man, I hope it gets cold. Come on man. Even going home to KS it will just rain. The cold keeps getting pushed back.

definitely been strange after such a fast start that the last couple of weeks have been hard to find snow much of anywhere

Hopefully the long awaited supposedly great winter begins soon

[Cpv17]

If this ssw event can change the teleconnections around to favorable conditions and the mjo moving into favorable phases then look out!! We could be dealing with something epic happening. I think it will get cold, but we must have patience. All of the analog years have pretty much been spot on so far over the last couple months. Below average temps for October and November followed by a big December warmup..so far that has been spot on with the analogs. Then after that the bottom drops out for January and February so there’s a pretty strong signal pointing towards some cold air heading our way.

[Haris]

[Brent]

Euro doesn't have the snowstorm at the end of the run now just rain

Barely 40 Saturday and next Wednesday 25 at DFW though

[wxman57]

With all the warm weather (no snow) predicted by the models, the NHC wants you all to know that they'll remain ever-vigilant in case any out-of-season hurricane threatens.

[WinterMax]

Model watching is painful, and im just starting to understand that they don't really know what they are talking about anywhere outside of about 3 or 4 days

[wxman57]

If you REALLY want to know what will happen over Texas the first week of January, take a look at the comparison of 500mb charts from the EC (left) and GFS (right) for 240 hrs. Somewhere between a deep upper-level low over South Texas and a big ridge overhead. That clears things up.

[WinterMax]

What does that mean for weather dummies?

[northjaxpro]

What does that mean for weather dummies?

Well, based on the example wxman 57 gave us, what does it mean with the current pattern?

Do not trust the models up to 10 days

[rwfromkansas]

Already storms here in Abilene before we head home today and go to KS tomorrow. This cloudiness will probably lessen the severe risk for DFW as predicted.

[wxman57]

What does that mean for weather dummies?

Well, based on the example wxman 57 gave us, what does it mean with the current pattern?

Do not trust the models up to 10 days

Precisely. Models are predicting cold and stormy (EC) or warmer and dry (GFS). I wouldn't trust the models beyond 3-4 days.

[TeamPlayersBlue]

I understand its too far out, but for the sake of education for this model stuff, what would surface conditions look like? Similar to the last massive ULL? Thought these things were rare?!

[South Texas Storms]

Rain showers will likely increase in coverage through the day as a potent disturbance approaches from the west. A line of strong to severe thunderstorms is forecast to develop across the Texas Hill Country around sunset as a cold front begins to push into a moist and unstable air mass. The line of storms is forecast to track eastward during the evening and overnight hours, with it likely reaching the IH-35 corridor around midnight. The strongest storms will be capable of producing frequent lightning, hail, strong wind gusts, and heavy rainfall. An isolated tornado cannot be ruled out.

HRRR Forecast radar at 11pm tonight:

[TheAustinMan]

I understand its too far out, but for the sake of education for this model stuff, what would surface conditions look like? Similar to the last massive ULL? Thought these things were rare?!

Per the same model guidance, it would indeed be quite stormy (widespread 1-3" of rainfall). Temperatures a bit cool but on the model it dredges up warmer tropical air moreso than cooler continental air so the results are in the mid-40s to mid-50s statewide.

Meanwhile things are starting to heat up across the state this morning ahead of the front. Currently a few disorganized bands of thunderstorms along a line from Abilene to Wichita Falls as well as some light shower activity across the Hill Country.

747 kB. Source: College of DuPage