STORM2K

Update from Jeff Lindner:

Period of active weather late Wednesday-Thursday.

A few severe thunderstorms including isolated tornadoes will be possible over SE TX on Thursday.

Southerly winds will return to the area later tonight into Wednesday with onset of moisture advection off the western Gulf of Mexico. An upper level trough will approach from the west late Wednesday with surface low pressure being forced to develop over north Texas Wednesday night and moving eastward toward northern Louisiana on Thursday. In response to the formation of lower pressures near the Red River, low and mid level wind fields will respond over SE TX. A low level jet of 35-45kts will develop from off the lower TX coast into central TX early Thursday with a broad region of warm air advection and gradual lift over the area. Significant low level air mass recovery will take place along the upper TX coast early Thursday with upper 60 to low 70 degree dewpoints moving inland across areas near and south of I-10.

By mid morning on Thursday wind profiles will become supportive of low level turning and increasing speed and vertical shear over the area. Stronger forcing arrives into the midday and early afternoon hours and expect an increase in widespread shower and thunderstorm development. A few of the showers or storms rooting near the surface will have favorable wind profiles for tornado production when overlaid with a very moist and somewhat unstable atmosphere. This looks to be a fairly common US Gulf coast cool season tornado potential with highly favorable wind fields but marginal instability. Additionally, 50kt southerly flow at 850mb will support gusty winds in showers and thunderstorms and even local gradient winds of 25-35mph will be possible on Thursday.

Overall the window for any severe weather is fairly narrow (900/1000am-200/300pm) on Thursday. Main threats will be damaging winds and isolated tornadoes. SPC has brought the entire area into a slight (2 out of 5) risk for severe weather on Thursday, but think the greatest risk will be along and south of HWY 105 where the highest moisture values will push inland. While moisture levels will be high fast storm motions should help to negate any flash flood threat with a general 1-2 inches of rainfall most likely with the highest amounts along and east of I-45.

Surface front sags to the coast on Friday and stalls across the coastal waters while El Nino enhanced sub-tropical jet stream aloft carves across the western Gulf and TX coast. This will likely keep clouds and at least some chance of light rain in the forecast over the weekend, but much of this will depend on how far north disturbances track out of Mexico.

Severe Weather Outlook (Thursday):


Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District
9900 Northwest Freeway | Houston, Texas 77092
346-286-4000 (main) | 346-286-4165 (direct) | 281-924-2091 (cell)
jeff.lindner@hcfcd.org | Twitter: @jefflindner1

It looks like winners and losers for this next rain event will be decided by I35. Hopefully, things pull back west some

A few days ago I thought the focus for severe weather would be the arklatex region, but it’s pretty clear now it’ll be too cool that far north to break the capping. Still, might be enough elevated instability to produce some isolated small hailers up there. Guess we’ll see

Looks like 1-2" of rain is a good bet for my part of East Texas Thursday into Thursday night. Hope some of it can get pushed west for others still.

EEEEKKK

That EPS run is Disgusting, if their was a skip button for the first half of december, id gladly push it!

bubba hotep wrote:EEEEKKK

https://www.tropicaltidbits.com/analysis/models/eps-fast/2023112812/eps-fast_T850a_namer_11.png

That just means it’ll flip back to cold. Seesaw time. Positive vibes.

Cpv17 wrote:

bubba hotep wrote:EEEEKKK

https://www.tropicaltidbits.com/analysis/models/eps-fast/2023112812/eps-fast_T850a_namer_11.png

That just means it’ll flip back to cold. Seesaw time. Positive vibes.

Yeah if we don't have a hard flip in December I will be shocked

Feel free to quote me in a month if we torch all month

I just hope we get a little surprise snow sometime in December, all of us! We've seen plenty of cold snaps since 2020 but the past two years its mostly been ice. It's been a hot minute since we've had an overperforming ULL that brings heavy, wet fluffy snow.

Ntxw wrote:I just hope we get a little surprise snow sometime in December, all of us! We've seen plenty of cold snaps since 2020 but the past two years its mostly been ice. It's been a hot minute since we've had an overperforming ULL that brings heavy, wet fluffy snow.

December 2020 had a lot of surprises for me

Brent wrote:

Cpv17 wrote:

bubba hotep wrote:EEEEKKK

https://www.tropicaltidbits.com/analysis/models/eps-fast/2023112812/eps-fast_T850a_namer_11.png

That just means it’ll flip back to cold. Seesaw time. Positive vibes.

Yeah if we don't have a hard flip in December I will be shocked

Feel free to quote me in a month if we torch all month

Just copy and past it to the Winter forum, then we are all set.

Iceresistance wrote:

Ntxw wrote:I just hope we get a little surprise snow sometime in December, all of us! We've seen plenty of cold snaps since 2020 but the past two years its mostly been ice. It's been a hot minute since we've had an overperforming ULL that brings heavy, wet fluffy snow.

December 2020 had a lot of surprises for me

2020 in general was full of surprises........

 https://twitter.com/1900hurricane/status/1729696286209659096

bubba hotep wrote:EEEEKKK

https://www.tropicaltidbits.com/analysis/models/eps-fast/2023112812/eps-fast_T850a_namer_11.png

Mild Pacific air floods North America, courtesy of the stratospheric Canadian Warming. That feature is progged to weaken slowly in mid–December.

1900hurricane wrote:https://twitter.com/1900hurricane/status/1729696286209659096

Similar to what I just commented on the Wx Infinity Forum, that's a lot of pure streamwise vorticity depicted in that 00Z HRRR Hodograph

Morning update from Jeff Lindner:

Severe thunderstorms will be possible on Thursday over SE TX.

A strong upper level storm system will move across TX on Thursday helping to develop deepening surface low pressure over NW TX early Thursday morning. Warm sector air mass over coastal SE TX early Thursday will spread inland through the morning into the early afternoon hours on a strong low level jet of 40-50kts around 5,000 ft. Warm front will slowly advance northward over the area and likely reach a line from College Station to Liberty by early afternoon. Veering wind profiles with height will support strong low level shear by mid to late morning over much of SE TX. However, while low level shear will be enhanced over the area, there are a few negative factors on Thursday that may keep the severe threat more isolated than widespread. First instability is lacking some, and while it does not take a lot of energy this time of year especially with the strong shear in place, this may keep storms more isolated. Additionally, mid level temperatures begin to warm during the day, and this may act to cap the low level air mass some and prevent deeper convection from developing.

Showers and thunderstorms will begin to develop early Thursday as lift increases over the area and the surface warm front lifts northward. The severe weather threat will increase from the mid morning hours into the mid to late afternoon hours when shear values will be maximized and instability the strongest. Greatest severe threat will likely be along and just north of the warm front and on the northern edge of the increasing mid level temperatures….or roughly along and north of I-10. Given the slightly backed low level winds near the warm front…SPC has included a 10% tornado probability within 25 miles of a given point for areas north of I-10 on Thursday and upgraded this area into the “enhanced” (3 out of 5) risk for severe weather. The rest of SE TX is in a slight (2 out of 5) risk.

While isolated tornadoes will be the main threat on Thursday, damaging winds of 60-70mph will also be possible given strong low level wind fields. In fact it will not take much for scattered showers the bring down some of the stronger winds aloft and even non-severe gusts of 40-50mph will be possible with the fast moving showers. As low pressure deepens over N TX during the day, the local pressure gradient will become increasingly tight with frequent 25-35mph winds across the area Thursday.

Severe Weather Parameters (Thursday):




Timing: 900am-400pm
Threats: isolated tornadoes/damaging winds
Risk area: highest north of I-10, but entire area is at some risk.

Radar:
The Houston/Galveston radar is currently down for the next 2 weeks undergoing life extending upgrades…nearby radars from Lake Charles, Corpus Christi, Granger, and Austin/San Antonio along with the terminal dopplers at IAH and HOU can be used in place of the HGX radar while it is down.

Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District
9900 Northwest Freeway | Houston, Texas 77092
346-286-4000 (main) | 346-286-4165 (direct) | 281-924-2091 (cell)
jeff.lindner@hcfcd.org | Twitter: @jefflindner1

A little surprised they already upgraded to enhanced on the Day 2, overall environment and storm mode still seems a bit questionable. Interesting probs too, not too often you see a 10% tor area with just 5% wind and hail.

If any cells can stay discrete enough they'll probably produce though so it could get dangerous.

ElectricStorm wrote:A little surprised they already upgraded to enhanced on the Day 2, overall environment and storm mode still seems a bit questionable. Interesting probs too, not too often you see a 10% tor area with just 5% wind and hail.

If any cells can stay discrete enough they'll probably produce though so it could get dangerous.

SPC mentioned that this is a conditional setup since the morning convection could mess up the instability.

First part of December looks docile. One of our two better months for wintry precip.

Maybe we can get some holiday fun before the January dry spell sets in.

This “El Niño” has been very tame so far.

This is the proper spot if you want a cold blast by Christmas


https://s5.gifyu.com/images/SRo9Y.png