January 2020: Unsettled WX Week Ahead

[harp]

The 0Z GFS! Holy Moly!!!

[kyzsl51]

The 0Z GFS! Holy Moly!!!

I think it's safe to say at the very least its gonna pretty cold in our neck of the woods within the next couple weeks.

[DoctorMu]

The 0Z GFS! Holy Moly!!!

GFS and Canadian are sniffing major fronts on a week and beyond. Possible mischief on the 19th. A ways off, but we might get winter after all.

Still waiting to see if the Euro joins the action.

[harp]

The 0Z GFS! Holy Moly!!!

GFS and Canadian are sniffing major fronts on a week and beyond. Possible mischief on the 19th. A ways off, but we might get winter after all.

Still waiting to see if the Euro joins the action.

Let us know about the Euro. Thanks.

[DoctorMu]

Holy mother of Arctic cold fronts on the 18z GFS. 50 degree drop the beginning of the week of the 20th

That would be insane! Has us below freezing for a few days If it were to pan out.

52°F drop and 78 hours below freezing in B/CS. We'll see.

[Katdaddy]

Its a warm, humid, and breezy morning across SE TX. It feels like Spring in January and then stage is set for a significant severe weather event across the S Plains and lower MS Valley this afternoon and overnight. A moderate risk area exists across SE OK, NE TX, SW AR, and NW LA with an enhanced risk area over much of SE TX. A strong squall line will move across SE TX tonight with damaging winds and possible tornadoes. Late this afternoon and this evening we need to be weather aware. If thunderstorms are abled to develop; they would quickly evolve into supercells with a tornado threat.

From this mornings Houston-Galveston NWS Area Forecast Discussion:

So, to try to summarize everything up, here`s where we stand early
this morning:

- Several environmental factors exist to support an unseasonably strong severe weather event in the next 30ish hours across Southeast Texas. The most likely scenario is for a line of strong to severe storms to enter the area from the west/northwest this evening, reach the Houston metro within a couple hours of midnight, and exit to the east before dawn.

- There are also multiple mitigating factors that may help us in failing to realize that higher end of potential. Mitigating factors look to become more important the farther south in Southeast Texas you look.

- Damaging wind gusts will be the main threat in this event. Tornadoes will also be possible, and will carry the additional dangers of forming very quickly and at night.

- Hail threat lags the other two hazards, but is still present. Areas well inland and near/west of the Brazos will see the best chance for hail, and threat will diminish coastward and as storms march east through the night.

- The cap is expected to hold across the area this afternoon. Should this event over-perform and storms erupt in the afternoon, the environment would be favorable for supercells and tornadoes. While the most likely scenario is for a dry afternoon, it will be wise to stay alert to potential changes in weather threats, just in case.

[MontgomeryCoWx]

The 0Z GFS! Holy Moly!!!

Give me the 0z GFS with a week below freezing and 7 inches of snow and you warm weather loving weirdos can have an early Spring.

I head north to Montana in February and March

[stormlover]

HRR isn't to impressed with todays systems so we shall see.

[srainhoutx]

Friday morning severe weather briefing from Jeff:

Risk of severe weather tonight across the area



Main threats:

· Straight line damaging winds of 60-75mph

· Isolated tornadoes

· Isolated large hail



Timing:

· 600-1100pm west (College Station to Columbus)

· 900-100am central (I-45 corridor, metro Houston)

· 1100pm-200am east (Lake Livingston to High Island)



Discussion:
Strong upper level trough digging into TX this morning with large warm sector in place over SE TX and powerful low level jet of 55-65kts over the eastern third of TX. Low level jet has brought tremendous moisture return across the area with surface dewpoints pushing into the upper 60’s and lower 70’s. Air mass over the area is capped and this will prevent any significant storms until very late this afternoon or more likely tonight. Surface winds are already in the 15-25mph range and these speeds will increase into the 20-30mph range this afternoon as surface low pressure deepens across N TX and OK. Widespread low cloud deck this morning will likely inhibit surface heating today and help maintain cap in play through much of the day. As deep layer ascent approaches this evening combined with surface forcing along the leading edge of the cold front, surface parcels should be forced through the weakening cap allowing a line of storms to develop (near I-35). Expectation is that capping over SE TX will hold through much of the afternoon and the chances for discrete supercells across the warm sector ahead of the approaching squall line appears low. While this threat it low, if a storm is able to develop and break the cap, extremely favorable low level shear profiles will be in place that would support strong low level rotation and a tornado threat. Best chances (still low) for any cells to break the cap will be in the Lake Livingston area (Walker, Polk, San Jacinto, Trinity Counties) where the cap is weakest. A much more significant risk of potentially long tracked tornadoes will reside N of SE TX over the ARKLATX region.

Later tonight the development of a squall line along the I-35 corridor will move across SE TX. Main threats with this line will be damaging winds and isolated tornadoes in any kinks or meso vortex signatures along the line. Line will move quickly across the area with forward speeds of 35-55mph. Any bowing segments in the line will likely produce corridors of wind damage. Highest severe threat will be along and N of HWY 105 with the less threat toward Matagorda Bay where the line may be more broken in nature.

Expect tornado or severe thunderstorms watches to be required for portions of SE TX by late this afternoon into the overnight hours.

Summary:

Worst of the weather will be overnight with a squall line that crosses the region with main threats being damaging winds and isolated tornadoes.

Stay weather aware and make sure cell phones have wireless emergency alerts enabled (on) since much of the weather will likely occur late tonight into the overnight hours.

Severe Weather Outlook (Today and Tonight):

[harp]

The 0Z GFS! Holy Moly!!!

GFS and Canadian are sniffing major fronts on a week and beyond. Possible mischief on the 19th. A ways off, but we might get winter after all.

Still waiting to see if the Euro joins the action.

Let us know about the Euro. Thanks.

It may have been one time eye candy...06Z takes it away. The cold still there, just not the precip.

[don]

I notice the 12z NAM really starts to intensify the line in the eastern half of Harris county once the line reaches the I-45 corridor fwiw. It also shows signs of discreet cells in front of the squall line along and east of the I-45 corridor.

[BlueJay]

The wind is picking up. Hopefully more pine needles will be blown OFF the roof than ON it.

I hope eveyone fairs well during tonight's storm.

[harp]

And....the 12Z goes back to reality.... *poof*!

[kyzsl51]

And....the 12Z goes back to reality.... *poof*!

Models have always flip flopped when weve had our most powerful arctic blasts and wintry weather. Still plenty of time!

[srainhoutx]

The 12Z GEFS (ensemble) suggests much colder air arrives later next week. Those operational runs will flip flop daily at that range. I do see growing signs of a fairly significant pattern change brewing after mid January. The MJO appears to be coming alive and amplifying. I expect a great deal of model volatility over the next week.

Regarding the severe threat, our neighbors in N Central/NE Texas and NW Louisiana appear to have the greatest chance of tornadoes and severe thunderstorms this afternoon and evening. SE Texas folks do need to stay weather aware tonight as well as our neighbors further East early tomorrow morning and throughout Saturday.

[Andrew]

Tonight could be interesting to watch even down here as models have been pretty aggressive with the dynamics of this system. Wind profiles later this evening and when the line arrives are rather impressive, especially for this time of the year. Looks like we will have a 60-70kt LLJ screaming across the region. CAPE looks marginal but there should be more than enough lift to keep storms firing. We will also have to track any embedded rotation, especially during that 8-10pm period. Keep an eye on the weather tonight everyone!

[MontgomeryCoWx]

The 12Z GEFS (ensemble) suggests much colder air arrives later next week. Those operational runs will flip flop daily at that range. I do see growing signs of a fairly significant pattern change brewing after mid January. The MJO appears to be coming alive and amplifying. I expect a great deal of model volatility over the next week.

Regarding the severe threat, our neighbors in N Central/NE Texas and NW Louisiana appear to have the greatest chance of tornadoes and severe thunderstorms this afternoon and evening. SE Texas folks do need to stay weather aware tonight as well as our neighbors further East early tomorrow morning and throughout Saturday.

Yep, outside 7 days, the Operational is simply another run that can be lumped into the ensembles. The ingredients are all there upstream, especially as they are progressing from Okhotsk to Alaska to our MJO favored areas.

As for today, I'm very concerned for my hometown of Longview as they are under the gun. Luckily, my parents have an underground closet in their garage. As for Houston, we aren't out of the woods, and these type of systems have a tendency to surprise those not expecting the worst.

[harp]

The 12Z GEFS (ensemble) suggests much colder air arrives later next week. Those operational runs will flip flop daily at that range. I do see growing signs of a fairly significant pattern change brewing after mid January. The MJO appears to be coming alive and amplifying. I expect a great deal of model volatility over the next week.

Regarding the severe threat, our neighbors in N Central/NE Texas and NW Louisiana appear to have the greatest chance of tornadoes and severe thunderstorms this afternoon and evening. SE Texas folks do need to stay weather aware tonight as well as our neighbors further East early tomorrow morning and throughout Saturday.

Yep, outside 7 days, the Operational is simply another run that can be lumped into the ensembles. The ingredients are all there upstream, especially as they are progressing from Okhotsk to Alaska to our MJO favored areas.

As for today, I'm very concerned for my hometown of Longview as they are under the gun. Luckily, my parents have an underground closet in their garage. As for Houston, we aren't out of the woods, and these type of systems have a tendency to surprise those not expecting the worst.

You've been pretty steadfast in your thoughts about a coming pattern change.

[DoctorMu]

12z GFS moves the really cold stuff east.

[DoctorMu]

Ensembles bring light freezes to B/CS. No freeze in HOU. Euro is colder than before, but also pushes cold east. Solutions are narrowing.