Texas Spring 2019

[weatherdude1108]

Don't worry, Euro Weeklies are super wet

[weatherdude1108]

We'll have to go back to the basics of weather prediction -- instinct.

[bubba hotep]

Highly uncertain forecast this weekend for N. Texas. We could see up to 3 rounds of svr storms or maybe only one.

[bubba hotep]

Saturday



Sunday

[dhweather]

Highly uncertain forecast this weekend for N. Texas. We could see up to 3 rounds of svr storms or maybe none.

Fixed that for you.

[dhweather]

[Ntxw]

I'm guessing the main event is Saturday with a line moving through about midday. Sunday is a lot more broken and spotty with better forcing to the east and maybe south.

The bigger story will be the mid April chill that may set in, relative to normal of course. All in all, severe modes, watches, warnings, might be on track to be well below normal for what typically is the "tornado" month for DFW.

[Haris]

I'm guessing the main event is Saturday with a line moving through about midday. Sunday is a lot more broken and spotty with better forcing to the east and maybe south.

The bigger story will be the mid April chill that may set in, relative to normal of course. All in all, severe modes, watches, warnings, might be on track to be well below normal for what typically is the "tornado" month for DFW.

What about Austin? I see that most models now agree on another low to move across coastal Texas Sunday. We might get clipped here.

[bubba hotep]

I'm guessing the main event is Saturday with a line moving through about midday. Sunday is a lot more broken and spotty with better forcing to the east and maybe south.

The bigger story will be the mid April chill that may set in, relative to normal of course. All in all, severe modes, watches, warnings, might be on track to be well below normal for what typically is the "tornado" month for DFW.

Finally a NAO/EPO negative pair lol

I wouldn't rule out 30s for portions of DFW

[Ntxw]

I'm guessing the main event is Saturday with a line moving through about midday. Sunday is a lot more broken and spotty with better forcing to the east and maybe south.

The bigger story will be the mid April chill that may set in, relative to normal of course. All in all, severe modes, watches, warnings, might be on track to be well below normal for what typically is the "tornado" month for DFW.

What about Austin? I see that most models now agree on another low to move across coastal Texas Sunday. We might get clipped here.

Austin definitely has a better shot at 2 decent events. Sunday may be a more persistent coverage of activity down that way with the second upper level disturbance.

[weatherdude1108]

Bob Rose:

Friday, April 5, 2019 4:02 PM
​
Weather conditions are quiet across the region on this Friday. Satellite images show a large area of low clouds covering the Hill Country along with most of South and Southeast Texas. Forecasts call for these clouds to be rather persistent and this will lead to a mostly cloudy to overcast sky through late afternoon. With widespread clouds in place, today's temperature should warm to around 80-82 degrees.

Forecasters are closely monitoring a vigorous trough of low pressure located over Baja, California and a second trough located off the central coast of California. Both systems are moving to the east and look to influence our region's weather over the weekend. The first trough is predicted to push into West Texas tonight and move across North Central Texas Saturday morning. Out ahead of the approaching trough, the atmosphere is forecast to become quite moist and increasingly unstable. There will be a slight chance for a few isolated rain showers and thunderstorms across the region this evening, with the chance for rain and storms increasing to 40 percent after midnight.

High-resolution forecasts call for the development of a large, organized area of rain showers and thunderstorms across West Texas and the Edwards Plateau late tonight. This activity is forecast to spread east into the Hill Country before sunrise Saturday, reaching the Austin/Interstate 35 corridor by about mid-morning. The area of rain and storms should continue marching east across Central Texas and the coastal plains region Saturday morning into Saturday afternoon. Atmospheric conditions appear favorable for some of these thunderstorms to become strong and severe. Severe weather threats will include large hail, damaging winds large hail and even a couple of isolated tornadoes. The Storm Prediction Center has placed the entire region under a Slight Risk for severe thunderstorms. (A slight risk means short-lived, isolated intense storms will be possible) Rain showers and isolated thunderstorms are forecast to continue behind the initial wave of rain and thunderstorms Saturday morning through Saturday afternoon. High temperatures Saturday will generally be in the mid and upper 70s.

Occasional rain showers and isolated thunderstorms are forecast to continue across the Hill Country and Central Texas regions Saturday night. Meanwhile, more organized and heavier rains are forecast to continue across the coastal plains region. The probability for rain Saturday night will be around 50 percent.

Rain amounts Saturday are predicted to average around 1 inch, with isolated totals to near 2 inches possible.

A second area of rain showers and thunderstorms is forecast to develop across the eastern Hill Country and the Interstate 35 corridor Sunday morning as the second trough of low pressure pushes into West Texas. Some of these storms could be strong to severe. The Storm Prediction Center has placed the area roughly along and east of Interstate 35 under a Slight Risk for severe thunderstorms Sunday. The primary severe threats will be large hail and damaging downburst winds. This rain and thunderstorm activity will push east across Central Texas and the coastal plains region Sunday morning into Sunday afternoon. Rain showers are forecast to diminish from west to east Sunday afternoon as the activity spreads southeast to the coast. In fact, some breaks in the clouds will even be possible Sunday afternoon. Rain amounts Sunday are forecast to average less than a half inch across the Hill Country but do look to average between 1 and 1.5 inches for areas along and east of Interstate 35. Sunday's temperature will be a little warmer, with highs in the low 80s.

There will be a slight chance for a few additional light rain showers Sunday night when a Pacific cold front pushes east across the state. Rain amounts should average near or less than a tenth of an inch.

Weekend rain totals are forecast to be highest for areas east of Interstate 35 and lowest across the Hill Country. The National Weather Service's rainfall forecast for the period between Friday morning and Monday morning calls for general totals of 0.5 to 1 inch across the Hill Country, with general totals of 1-2 inches for locations east of Interstate 35.

A sunny, dry and warm weather pattern is forecast to develop Monday through Wednesday as the weekend trough of low pressure pushes off to the northeast. Breezy south winds at 10-20 mph are forecast Tuesday and Wednesday in response to an area of low pressure moving across the Plains states. High temperatures Monday will be in the low 80s, warming to the mid to upper 80s Tuesday and the upper 80s Wednesday.

Sunny and slightly cooler conditions are forecast next Thursday, continuing into next weekend as a Canadian cold front moves through the area. High temperatures will fall to the 70s with low temperatures in the 50s.

The next chance for rain is forecast to occur next weekend, April 13th and 14th when another trough of low pressure moves into Texas out of Mexico and the eastern Pacific.

Have a good weekend.

Bob

https://www.lcra.org/water/river-and-we ... ather.aspx

[Ntxw]

I'm guessing the main event is Saturday with a line moving through about midday. Sunday is a lot more broken and spotty with better forcing to the east and maybe south.

The bigger story will be the mid April chill that may set in, relative to normal of course. All in all, severe modes, watches, warnings, might be on track to be well below normal for what typically is the "tornado" month for DFW.

Finally a NAO/EPO negative pair lol

I wouldn't rule out 30s for portions of DFW

We haven't yet experienced the final warming (Spring) of the stratospheric vortex. It's been a late, displaced, Winter -> Spring transition. We've seen this happen a couple of times. Until that final warming occurs we may experience chilly (compared to normal) snaps through May.

Is it ENSO? Is it low sunspots? Maybe a combination of both and more.

[weatherdude1108]

EWX office discussion:

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
329 PM CDT Fri Apr 5 2019

.SHORT TERM (Tonight through Saturday Night)...
Visible satellite imagery this afternoon shows an agitated cumulus
field developing across the Rio Grande Plains with ample heating
allowing for temperatures to rise into the mid to upper 80s along the
Rio Grande. As forcing for ascent continues to overspread the region
ahead of a disturbance over southern Arizona/ northern Mexico later
this afternoon and evening, high resolution guidance has remained
consistent in an isolated thunderstorm or two developing across the
higher terrain of Mexico and quickly propagating towards Val Verde
County. Loss of heating will result in this first, initial round of
activity quickly tapering off by mid-evening and expect the region to
remain rain-free this evening.

Deepening lee side troughing over the High Plains in response to the
approach of the upper level disturbance is expected to result in a
secondary round of thunderstorm development across West/West Central
Texas into the Edwards Plateau and possibly as far south as the Rio
Grande Plains overnight. The southern extent of development remains
somewhat uncertain as the 12Z suite of model guidance remains varied
on where the greatest lift will be realized across the western half
of the state... and this is resulting in model solutions overnight
indicating everything from thunderstorm activity remaining well north
of the region to a broken line of thunderstorms propagating from the
west/southwest towards Interstate 35 during the morning hours.

What does appear to be certain at this point is that rain chances
Saturday will be heavily dependent on what happens overnight. The
approaching disturbance will also contribute to a strengthening 30-35
knot low level jet, which will help a stationary front along the
Texas coast lift inland and result in another round of low clouds and
possibly some drizzle along and east of Interstate 35 early Saturday
morning. This initial boundary appears to lose definition as it
lifts into Central Texas, but several convection allowing models are
indicating that the West/West Central Texas thunderstorm activity may
develop a strong enough cold pool to allow an outflow boundary to
move into the Hill Country by Saturday morning. This would serve as a
focus for continued development during the day Saturday as the main
disturbance arrives. However, the past few runs of the HRRR do not
develop an outflow boundary and keep all activity north of the
region. Given the presence of good lift across the region, steep mid-
level lapse rates, and plenty of shear, expect at least scattered
thunderstorm development to occur across the region during the day
Saturday. A lull in the activity will be possible by Saturday evening
before a secondary round develops as the main disturbance lifts
across the region. Based on the farther south trajectory, anticipate
greatest rain chances south of the Interstate 35 corridor on Sunday
morning.

Thunderstorm threats tonight and Saturday appear to range from
damaging wind, large hail, and frequent lightning. Steep lapse rates
in excess of 8 C/km will not only contribute to this hail and wind
threat, but high resolution guidance has been fairly consistent in
indicating the presence of bowing line segments (raising concerns for
the damaging wind threat). There has been an intermittent signal for
potentially discrete cells developing ahead of these bowing segments
east of Interstate 35, which may also be capable of an isolated
tornado threat. This would be heavily contingent on surface
destabilization during the day across these areas... which the
presence of low clouds/drizzle may complicate. Cannot rule out the
threat for locally heavy rain given the instability present, but
precipitable water values less than 1.5 inches and developing drought
conditions across portions of the region will help mitigate against
any widespread flood threat.

&&

.LONG TERM (Sunday through Friday)...
The disturbance begins to close off over the ArkLaTex on Sunday with
associated north/northwest flow pushing Sunday morning rain chances
off to the east by Sunday afternoon. This will help western areas dry
out and heat up into the low to mid 80s by Sunday afternoon with
slightly cooler highs in the mid 70s to low 80s across the east.
Steep lapse rates and long, skinny CAPE profiles indicating water-
loading of updrafts will contribute to a lingering damaging wind
threat across the Coastal Plains Sunday morning along with the threat
for locally heavy rain.

A few wraparound showers may be possible across portions of the
Brazos Valley/Central Texas into the Coastal Plains Sunday night into
Monday morning as the upper low ejects towards the northeast, but
dry conditions are expected through the workweek. Shortwave ridging
building in behind this system will result in temperatures rising
into the mid 80s to low 90s across the central and eastern portions
of the region mid-week with the Rio Grande possibly seeing the first
100 degree day of the year on Wednesday. A fast-moving shortwave
trough traversing the Central Plains Wednesday into early Thursday
will send a dry cold front across the state on Thursday. Somewhat
cooler high temperatures in the low 80s to low 90s are expected as
the front passes Thursday with highs finishing the work week in the
low 70s to low 80s as additional cooler air filters into the region.

&&

[bubba hotep]

Trends on the HRRR look favorable for DFW heading into tomorrow. The 18z extended run looks like a pretty classic DFW heavy rain event.

[Cpv17]

Well I see the GFS is back to giving me a pretty good rain event here for this weekend after showing basically crickets just yesterday.

[Haris]

4.4” on the nam 3k

[weatherdude1108]

The weather service is having trouble with models. The weather guy on KXAN said these Pacific storms that travel across Mexico have limited data, so models struggle (which Ntxw mentioned a while back I think). Weather service said lack of forcing mechanisms with this storm (like a front) make it hard to pinpoint.

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1001 PM CDT Fri Apr 5 2019

.UPDATE...
The 500 mb trough axis currently resides from near the Mexico/AZ/NM
border and extends south into northern Mexico. Fairly robust deep
convection is ongoing from around Midland to just southeast of
Lubbock, with several severe thunderstorm warnings currently in
effect. It has been a fairly quiet evening across our region, however.
One lonely thunderstorm managed to develop near the Rio Grande west
of Langtry and is currently tracking across northern portions of Val
Verde County, and has not managed to come particularly close to
reaching severe criteria. In fact, it continues to weaken as it heads
northeast into a less favorable environment.

Perusing the most recent high-resolution and convection allowing
models, the 00z run of the 3 km NAM has backed off from developing
the robust squall line in the early morning hours that the 18z run
had developed. The HRRR continues to only develop some showers across
the region through much of the overnight period before finally
initiating some stronger storms out west across portions of the
southern Edwards Plateau/Hill Country by mid morning. However, these
are short-lived, and the HRRR continues to show the Austin and San
Antonio metro areas largely missing out on showers and thunderstorms
tomorrow altogether. The RAP, however, does develop fairly widespread
convection across the region tomorrow morning and into the early
afternoon hours, with respectable QPF totals (some areas above 2
inches), especially just west of Austin. In summary, there is still
quite a bit of uncertainty in how this system is going to develop and
evolve given the lack of a strong surface forcing mechanism like a
cold front.

Went ahead and made a few edits to the grids. Reduced PoPs for much
of the region in the 1 AM to 7 AM time period, especially for areas
along and east of I-35. It still looks looks like the best chances
for widespread showers and thunderstorms for much of the region,
especially the I-35 corridor and the Austin and San Antonio metro
areas, will be from 7 AM to about 1 PM tomorrow. Only made slight
edits to the PoP grids for this time frame, only trimming back PoPs
for locations south and southwest of San Antonio. Strong to severe
thunderstorms remain possible. SPC continues to keep our region under
a slight risk for severe thunderstorms. Primary hazards would be
strong winds and large hail, with a minimal tornado threat.

[gpsnowman]

Some nice cells popping up out west. Let's see what happens in the morning.

[Cpv17]

Idk what to think of the models anymore these days. It seems like they’ve gotten worse the past few years than better.

[Brent]

lol glancing at some hi res models now who knows if it will even rain

this is pathetic