Texas Winter 2016-2017

[Snowman67]

I see a lot of cold air building in Alaska over the next several days.

[bubba hotep]

Probably wouldn't take much to get the DFW area upgraded later today. FWD with a nice AFD for the threat today:

The first wave of activity will consist of scattered showers and
storms developing and streaming northward within the warm sector
late this afternoon and evening. The strong/severe potential with
this activity is highly dependent on the warm front`s behavior
and how much warming/moistening has taken place at the surface.
Most of this activity will be along/west of I-35 during this time
where the strongest warm advection will be situated. A low level
jet of 40-50 kts will have overspread the area by this time with a
mid-level speed max of 50+ kts nosing into the region as well.
With 0-1 km shear of 30 kts and 0-6 km shear of over 50 kts, the
resultant hodographs will certainly support rotating showers and
storms. As has been the case for the past few days, instability
remains to be the big question mark. If the warm front does lift
far enough north, 500-1000 J/kg of CAPE will exit in areas west of
I-35 and south of I-20 by late afternoon and evening. While much
of this buoyancy will be confined to the mid levels where cooling
due to ascent from the approaching upper low will steepen lapse
rates, the warm/moist air at the surface may result in surface
based instability. If an isolated storm is able to become surface
based during this time, there will be a severe potential
including tornadoes given the ample shear. Strong winds and some
hail will also be of concern. In addition to the severe threat,
there will also be a localized flood threat during this time. PW
values will climb to around +3SD above normal and thunderstorms
should be very efficient rain producers. If cell training occurs
(oriented S-N with the mean flow), a localized flash flood threat
will exist where some multi-inch rain totals could exist in a
short time.

HRRR has been pretty aggressive with the first batch of storms:

[1900hurricane]

I'm feeling somewhat skeptical of the severe weather threat today, but it does appear to at least be non-zero. At the time, there appear to be two areas of potential maxes. The first is further to the west near the Pecos River near the surface low, where the strongest warm air advection will occur. This area is the region that I think has a higher probability of producing. The second is on the slowly retreating warm front near the I-35 corridor, but this one is probably very conditional. So far, I have not been very impressed with airmass modification/warm front retreat, but it will probably pick up some as the Rio Grande surface low organizes and ejects. Here's a rough surface analysis I hastily made on my phone real quick.



The further east in the warm sector, the more poor the low level lapse rates will be. Storms in my eastern target may have to root themselves along/near the warm front to get going, and most guidance isn't doing that, although the HRRR is trying to some degree. The western target is too far away from me for a risk of this type, but I might try to target something near I-35 if I decide it looks ok.

[srainhoutx]

Sheets of rain in NW Harris County the past hour as brought a quick 1/2 inch in the rain gauge.

[BTAYLOR5021]

Can someone please give some much needed info on the potential arctic air intrusion towards the end of Jan beginning Feb time frame...I'm over this *January thaw* heat wave....this isn't fair to the winter snow and ice lovers...I pray wimter returns with a good grip.

[1900hurricane]

The 20Z SPC update gives me some confidence that I'm not completely incompetent.

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0158 PM CST Sun Jan 15 2017

Valid 152000Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
WEST-CENTRAL/NORTH-CENTRAL TX TO FAR SOUTHERN OK...

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN PLAINS...

...SUMMARY...
Scattered severe thunderstorms will be possible this afternoon and
tonight across west-central to north-central Texas and southern
Oklahoma. A few tornadoes, damaging winds, and large hail are
anticipated.

...20Z Update...
The severe threat across southwest into west TX is expected to
continue increasing through the afternoon. The only change to the
prior outlook across this area has been to account for the eastward
movement of the cold front and line of pre-frontal convection. The
northern extent of the appreciable severe risk remains confined by a
shallow cold and stable airmass over the TX Panhandle into southwest
OK. For more near-term meteorological details (through ~2130Z) on
the developing severe risk across southwest TX, see Mesoscale
Discussion 52.

There is some concern that isolated showers and thunderstorms
ongoing over parts of east TX in a warm air advection regime may
become surface based this afternoon and evening. Low to mid 60s
surface dewpoints across this region will continue to shift
northward into the Metroplex over the next few hours as a warm front
lifts northward. RAP/HRRR forecast soundings suggest that an
isolated tornado threat may develop with pre-frontal warm sector
convection as a low-level jet strengthens across central/north TX in
the 00-03Z timeframe. Have accordingly made a minor adjustment to
the 5% tornado probabilities in/around the Metroplex to account for
this scenario.

[gpsnowman]

Can someone please give some much needed info on the potential arctic air intrusion towards the end of Jan beginning Feb time frame...I'm over this *January thaw* heat wave....this isn't fair to the winter snow and ice lovers...I pray wimter returns with a good grip.

I'm curious as well, but after the potentially impacting rain event and the Cowboy game, winter's return will be on the radar again. From what I have read on this forum and elsewhere, winter will be back at some point.

[ThunderSleetDreams]

GO PACK GO!

[One Eye]

Go Dak Go!

[Yukon Cornelius]

GO PACK GO!

My wife is from WI so that's pretty much all I have been hearing today!

[Yukon Cornelius]

I went down to cabelas in ft worth today and the fog down this way is pretty crazy.

[JDawg512]

Here we go! Tornado watch has been issued from Austin to Dallas and points West. Already had a very heavy downpour and you can see the way the clouds are moving in different directions at different levels that there is turbulence in the atmosphere. Tornado Warnings west of Waco.

[Ntxw]

The cluster of storms ahead of the main line is always the areas to watch.

Tornado Warning
TXC035-217-160100-
/O.NEW.KFWD.TO.W.0004.170116T0022Z-170116T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Fort Worth TX
622 PM CST SUN JAN 15 2017

The National Weather Service in Fort Worth has issued a

* Tornado Warning for...
Eastern Bosque County in central Texas...
Southwestern Hill County in central Texas...

* Until 700 PM CST

* At 621 PM CST, a severe thunderstorm capable of producing a tornado
was located near Valley Mills, or 8 miles east of Clifton, moving
northeast at 35 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.

* This dangerous storm will be near...
Lake Whitney State Park around 645 PM CST.
Whitney around 650 PM CST.

Other locations impacted by this tornadic thunderstorm include Abbott
and Aquilla.

THIS INCLUDES INTERSTATE 35 between MILE MARKERs 357 and 364.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

[bubba hotep]

This one is getting close

[Ntxw]

And with the heartbreaker loss by the boys, we Texans have a long, warm period to mourn.



+EPO still and the -AO forecasts are not holding up

North Texas folks stay on alert for warnings

[TheProfessor]

That game was the epitome of this winter.

[Ntxw]

That game was the epitome of this winter.

Yeah, the back and forth but eventually the warmth wins

I.e. snowstorms have disappeared on the guidance

[1900hurricane]

Should have gone with my original idea for a target today, which was further north in Temple. I instead went down to Bastrop based on the convective trends at the time. Ooops (not that I was going to get a good view of any tornado anyway, with it becoming dark and all). The cell to the south running into the tornadic cell looks to have disrupted it for the time being at least.

[JDawg512]

That storm has had a confirmed tornado on the ground by law enforcement. Everyone in the DFW especially the eastern half should be watching this storm very closely. Stay safe!

[1900hurricane]

And with the heartbreaker loss by the boys, we Texans have a long, warm period to mourn.



+EPO still and the -AO forecasts are not holding up

North Texas folks stay on alert for warnings

That looks good for an active southern storm track, which is fine by me. This is one of my favorite looks personally, but I know some here don't share the same opinion.