Severe Weather 4-25 through 4-28-23

[cheese007]

Another week in April, another severe weather setup, this time across much of the central part of TX. Primarily wind/hail at this juncture

 

ZCZC SPCSWOD48 ALL ACUS48 KWNS 200900 SPC AC 200900 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Apr 20 2023 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 to Monday/Day 5... A moist airmass will likely remain over south-central Texas on Sunday, possibly advecting northwestward into west-central Texas on Monday. At upper-levels, a trough is forecast to move through the Desert Southwest early in the week. As surface temperatures warm each day, isolated thunderstorm development will be possible in the afternoon and evening. Although instability is forecast to remain relatively weak across most of the southern Plains, mid-level flow may be strong enough for an isolated severe threat. The greatest potential would be in south-central and west-central Texas, along the northern edge of the moist airmass. ...Tuesday/Day 6... On Tuesday, a lead shortwave trough ahead of the upper-level system, is forecast to move eastward into the southern High Plains. Low-level moisture is forecast to advect northward into much of the southern High Plains. It appears that moderate instability could develop across much of the moist sector as surface temperatures warm during the day. Moderate deep-layer shear combined with the instability should be favorable for severe storms. Some solutions suggest that a dryline will setup by afternoon across west-central Texas. Thunderstorms would likely form to the east of the dryline and move eastward across the southern Plains. Under that scenario, the greatest severe threat would be in parts of central and north Texas. Large hail and wind damage would be possible, especially if supercells can develop. ...Wednesday/Day 7 and Thursday/Day 8... An upper-level low is forecast to move across the Four Corners region on Wednesday, opening up into a trough over the southern Plains on Thursday. Isolated to scattered thunderstorms will be possible across the moist sector each day as surface temperatures warm. Although a severe threat may develop in areas that become sufficiently unstable, uncertainty is substantial concerning the location of the moist sector. A threat area could be added to either Wednesday or Thursday once this becomes more clear. ..Broyles.. 04/20/2023 CLICK TO GET WUUS48 PTSD48 PRODUCT

 

[weatherextreme]

Looks like that one bite the dust. Rip

[Torchageddon]

This isn't for the 25th but this outlook is strange for today:

 

Brownsville special.

[cheese007]

Edited title to reflect the D3 SLGT for Wednesday

[cheese007]

D1 Slight risk shifted west a good bit, while day 2 has been upgraded to Enhanced centered on the DFW metro

[Powerball]

On 4/21/2023 at 2:54 PM, weatherextreme said:

Looks like that one bite the dust. Rip

^^^This post might end up aging like milk.

[weatherextreme]

  On 4/21/2023 at 2:54 PM, weatherextreme said:

Looks like that one bite the dust. Rip

^^^This post might end up aging like milk.

 

 

 

Guessing that the SPC took off the original forecast (This was for the Tuesday forecast) due to it being more of a conditional threat.  Then they decided to add it back to the forecast when they had more confidence in the forecast?

[Powerball]

4 hours ago, weatherextreme said:

  On 4/21/2023 at 2:54 PM, weatherextreme said:

Looks like that one bite the dust. Rip

^^^This post might end up aging like milk.

 

 

 

Guessing that the SPC took off the original forecast (This was for the Tuesday forecast) due to it being more of a conditional threat.  Then they decided to add it back to the forecast when they had more confidence in the forecast?

Threat still reamins somewhat conditonal beacsue of the extensive cloud cover that will be expected and the weak LLJ, but it's a solid setup for flash flooding and large hail.

[nvck]

tor warning out for area near keenesburg CO, ne of Denver. it just kinda popped up without a severe tstm warning before it... warning text says spotter confirmed but not much on radar

[nvck]

the warning in question:

 

Tornado Warning issued April 25 at 2:42PM MDT until April 25 at 3:15PM MDT by NWS Denver CO
Counties: Weld, CO
The National Weather Service in Denver Colorado has issued a

* Tornado Warning for... South central Weld County in northeastern Colorado...

* Until 315 PM MDT.

* At 242 PM MDT, a confirmed tornado was located near Keenesburg, or 27 miles southeast of Greeley, moving south at 20 mph.

HAZARD...Damaging tornado.

SOURCE...Weather spotters confirmed tornado.

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.

* The tornado will be near... Prospect Valley around 245 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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.

[Chinook]

of course this is just before a snowstorm, because weather makes no sense

 

[Chinook]

they could see it from the airport, and apparently it lasted 9 minutes from 49 past the hour to 58 past the hour.

Quote

KDEN 252059Z 34020G27KT 10SM BKN090 BKN120 BKN220 14/03 A2981 RMK TORNADO E58 AO2 LTG DSNT W-NE CB DSNT NE T01390028

KDEN 252053Z 34020G27KT 10SM +FC SCT060 BKN100 BKN220 14/03 A2981 RMK TORNADO B49 AO2 PK WND 33027/2044 LTG DSNT W-NE SLP057 TORNADO B46 6NE MOV UNKN T01440028 55004
KDEN 252050Z 34020G27KT 10SM +FC SCT060 BKN100 BKN220 14/03 A2981 RMK TORNADO B49 AO2 PK WND 33027/2044 LTG DSNT W-NE TORNADO B46 6NE MOV UNKN

 

[mayjawintastawm]

The Keenesburg tornado was a landspout. There was some video someone took from a car, looks like they were on I-76. Little bitty thing. We had some nice sunshine today that yielded just enough instability to create some thunderstorms.

[weatherextreme]

 

Mesoscale Discussion 0618
   NWS Storm Prediction Center Norman OK
   1118 PM CDT Tue Apr 25 2023

   Areas affected...North TX into far southern OK

   Concerning...Severe potential...Watch unlikely 

   Valid 260418Z - 260615Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated hail is possible overnight. Watch issuance is
   considered unlikely.

   DISCUSSION...A strengthening low-level jet (as noted on recent KDYX
   and KFWD VWPs) is likely contributing to a recent increase in
   elevated convection across north-central TX. Meanwhile, a cluster of
   elevated convection associated with the remnant of an earlier
   long-lived supercell is moving eastward across western north TX.
   While increasing MLCINH will tend to suppress the redevelopment of
   surface-based convection, MUCAPE of greater than 1000 J/kg and
   effective shear of 40-50 kt will support some modestly organized
   elevated storms. A tendency for storm clustering may limit the
   threat to some extent (compared to more discrete development), but
   isolated hail will be possible with the strongest storms overnight.
   With the magnitude and coverage of this threat expected to remain
   relatively limited, watch issuance is considered unlikely at this
   time.

[mob1]

10 percent hatched tornado proba for Dallas. 

[cheese007]

Latest D1 is concerning for DFW 

SPC AC 261248

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0748 AM CDT Wed Apr 26 2023

   Valid 261300Z - 271200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   NORTH TEXAS AND CENTRAL FLORIDA...

   ...SUMMARY...
   A few tornadoes, along with very large/destructive hail, and severe
   thunderstorm gusts, are expected over parts of north Texas this
   afternoon and evening.  Very large hail and damaging winds also are
   expected over parts of central Florida.

   ...Synopsis...
   The primary mid/upper-level feature influencing this forecast is a
   compact cyclone -- apparent in moisture-channel imagery over the
   southern Rockies and centered near SKX.  A trough extends from the
   low southwestward across southeastern AZ, and northeastward to near
   IML.  The 500-mb low should move southeastward across northeastern
   NM today, then by 00Z, pivot eastward to the TX Panhandle, with
   through southwestward past ELP.  By 12Z, the perturbation should
   devolve to an open-wave trough with primary vorticity lobe over OK,
   and trough across west-central/far west TX.  A broad area of
   difluent, somewhat cyclonic flow will spread across the southern
   Plains to its southeast.  Several embedded, convectively induced/
   reinforced vorticity maxima will eject eastward across the Arklatex
   and Mid-South regions ahead of this feature.

   A continuing fetch of strong upper-level westerlies -- with
   weak/embedded perturbations -- will overlie the northern Gulf and
   FL.  One such weak shortwave trough is apparent over the north-
   central/northeastern Gulf, associated with a few thunderstorms
   southeast of LA.  This feature should reach peninsular FL by this
   evening.

   At the surface, a quasistationary front was drawn at 11Z across
   north-central FL and the northern Gulf, becoming a warm front over
   southeast through central TX, to a low between SWW-LBB.  A cold
   front extended from there southwestward over the lower Pecos Valley.
   The cold front will shift eastward over central/north TX through the
   period, while the warm front shifts northward today to near the DFW
   Metroplex, before being overtaken by convection.  The FL frontal
   segment should remain near its present position.

   ...North TX and vicinity...
   Widely scattered to scattered thunderstorms are expected to occur
   along and south of the warm front this afternoon, with all severe
   modes possible.  The main concern at first may be large to giant
   hail, with ideal conditions progged for generation of hailstones
   above 3 inches in diameter from any sustained supercell(s).  As
   early supercells move east-southeastward to southeastward across the
   region into greater low-level moisture and weak CINH along/south of
   the effective warm front, two processes should occur in tandem:
   1.  Enlargement of low-level hodographs during late afternoon into
   early evening,
   2.  Growth in convective coverage, ultimately leading to a line of
   strong-severe thunderstorms moving southeastward across central and
   northeast TX.  The resulting QLCS this evening will be mainly a
   damaging-wind threat with potential for significant/65+ kt gusts, 
   but with a couple tornadoes and isolated large hail still possible.

   While supercells still are present -- and especially along the warm
   front where low-level shear/vorticity will be maximized -- so will
   be the potential for tornadoes (some possibly capable of
   significant/EF2+ damage).  Uncertainties remain on mesoscale
   specifics of boundary position and mode-transition timing, but both
   giant hail and tornadoes are possible with the boundary potentially
   lying across some part of the Metroplex.  North of the boundary,
   isolated large hail still may occur from the most vigorous elevated
   convection across mainly the Red River region into parts of OK/AR. 
   This includes an ongoing, elevated cluster of thunderstorms over
   northwest TX and southwestern OK, which should move astride the Red
   River across southern OK and parts of north TX through the day.

   A corridor of 2500-3500 J/kg peak/preconvective MLCAPE should
   develop east of the cold front and southwest of the warm front
   through central TX, narrowing northward.  Strong veering of flow
   with height -- especially near the warm front -- will contribute to
   45-60 kt effective-shear magnitudes.  The largest hodograph sizes
   and SRH for surface-based, effective-inflow parcels should be along
   the warm front, but still will favor supercells in the warm sector. 
   Once the modal transition occurs, wind and tornado potential will be
   maximized near embedded mesocirculations and bow/LEWP features.

   ...FL Peninsula...
   Scattered, mainly afternoon to early-evening thunderstorms are
   expected across central and south FL, offering large hail and
   isolated damaging to severe gusts.  The greatest convective coverage
   potential and most-favorable environmental parameter space for
   significantly severe hail appears to be over portions of central/
   east-central FL this afternoon, where supercells with significant
   hail (2+ inches diameter) may occur.  Isolated damaging/severe
   downbursts also may occur, and a tornado is possible with help from
   storm-scale/boundary processes.

   Initial foci for convection will be sea-breeze boundaries near the
   East Coast, and farther inland from the Gulf.  With strong surface
   heating and abundant low-level moisture expected to minimize MLCINH
   by midday, outflow and differential-heating boundaries also may
   support storm initiation throughout the afternoon.  The coldest
   midlevel temperatures and steepest low/middle-level lapse rates are
   expected over central FL, associated with a remnant Mexican EML
   plume.  With surface dewpoints in the upper 60s to low 70s F,
   preconvective MLCAPE should reach 2500-3000 J/kg (locally higher). 
   Low-level flow will be weak, keeping hodographs small for the most
   part.  However, flow will veer strongly with height beneath
   favorable mid/upper winds of the subtropical jet, contributing to
   40-50-kt effective-shear magnitudes.  This, along with boundary
   interactions, will support supercell potential to maximize updraft
   strength and efficiency of hail production.  Hail-growth models
   applied to forecast soundings indicate potential for hailstones 2-3
   inches in diameter, perhaps from multiple storms.  The overall
   convective coverage/intensity should decrease markedly after about
   03Z, when outflow coverage is maximized and nocturnal boundary-layer
   stabilization is underway.

   ..Edwards/Leitman.. 04/26/2023

[Ed, snow and hurricane fan]

15 minutes ago, mob1 said:

10 percent hatched tornado proba for Dallas. 

10% hatched everything.  'Giant' hail mentioned.  FWS disco thinks the risk of convection S of the warm front this afternoon (before the CF approaches in the evening) is conditional, but if they develop they'll be significant.  They are planning another balloon launch weather permitting.

[WhirlingWx]

The storms near and south of Wichita Falls look like they're building south, they might impact northern DFW in a few hours at that rate. Might temper the threat for areas north of Dallas - Fort Worth later on, but still unsure.

[radarman]

 

1 hour ago, WhirlingWx said:

The storms near and south of Wichita Falls look like they're building south, they might impact northern DFW in a few hours at that rate. Might temper the threat for areas north of Dallas - Fort Worth later on, but still unsure.

Agree.

Very overcast and showery right now.  SPC meso discussion mentioned that gravity waves may help disturb the stratus, but not before the incoming stuff from the NW arrives.

I guess if there is a window for strong surface based convection you'd have to hope for the MCS to continue to deflect NE and maybe leave an OFB somewhere near I20, then clear out later on for a couple hours.  I dunno though.

[Powerball]

Very messy radar/satellite right now.

[mob1]

2 hours ago, WhirlingWx said:

The storms near and south of Wichita Falls look like they're building south, they might impact northern DFW in a few hours at that rate. Might temper the threat for areas north of Dallas - Fort Worth later on, but still unsure.

Definitely. I'd be very surprised if the threat doesn't shift significantly south and/or is tempered altogether. 

[Santa Clause]

Yeah today looks cooked 

[Ed, snow and hurricane fan]

13 minutes ago, Wmsptwx said:

Yeah today looks cooked 

I don't know, the storms in the Metroplex seem to be staying near I-20.  That could become the effective warm front later.  The HRRR is setting up the front closer to US 84 with a super cell with the proverbial gorilla hail near Waco this evening.

 

ETA- Surprised there isn't a severe warning for hail in NE Tarrant County.

[WhirlingWx]

I'm not sure that the warm front has moved any more than 10 miles north in the past 3 hours

Again, this is more of an observation for MBY. Still a threat that can materialize to the south imo

[cheese007]

FWD still seems bullish this afternoon/evening

000
FXUS64 KFWD 261720
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1220 PM CDT Wed Apr 26 2023

...New Short Term...

.SHORT TERM... /NEW/
/Severe Weather Today/

An episode of significant severe weather will materialize this
afternoon. North and Central Texas residents should be prepared
for large hail, damaging winds and a few tornadoes. In addition,
there will be a heightened flash flooding threat late this
afternoon across eastern portions of Central Texas and East Texas.

A cluster of elevated sub-severe storms continues moving eastward
across North Texas, leading to a continued threat for hail and
gusty winds along and north of the warm front. The warm front
generally resides along the I-20 corridor, evident by the
southerly component of the winds south of the front and
easterly/northeasterly winds north of the front. Although the
front is generally along the I-20 corridor, much of the region
continues to experience a fairly good amount of SBCIN in the wake
of earlier showers and storms as well as the dense cloud cover in
place.

As we approach the afternoon, the initial area to watch for rapid
thunderstorm development will be along/south of I20 and west of
US-281. Visible imagery is depicting partial clearing is ongoing
with temperatures approaching 80s degrees. With afternoon heating
and MLCAPE expected to exceed 2500 J/Kg, any thunderstorm that
develops will be capable of producing large hail that may approach
or exceed baseball size. Given that the storms south of the warm
front are likely to be surface based, not only will there be a
significant hail threat, but the tornado threat will also increase
as the storms move eastward. Surface southeasterly winds veering
with height will result in classic right-turning hodographs, with
a strong tornado or two not out of the question this
afternoon/early evening.

Additional convective development is expected along the true
front as it moves southward late this afternoon. Initial
thunderstorm development will likely be supercellular with a large
to very large hail threat continuing. Tornadoes and damaging
winds will continue to pose a threat south of the I-20 corridor,
generally across southern portions of North Texas and into Central
Texas.

As the supercells move eastward, the expectation is for upscale
growth into a complex of thunderstorms. There will be a
transition to mainly a damaging wind threat along with wind-driven
large hail. Sufficient 0-3km shear will be in place to mention
the potential for quick tornadoes along any north/south oriented
segment of the line of storms. As if that wasn`t enough,
torrential rainfall may lead to flash flooding, especially across
eastern portions of Central Texas and East Texas. Antecedent
conditions will lead to rapid runoff of any precipitation, and
with latest HREF PMM depicting isolated areas of 5" of rain, it`s
important to remain vigilant of flooded areas this evening and
tonight. If you come up on any flooded roads, TURN AROUND DON`T
DROWN!

The bulk of the convection should be exiting our region by around
midnight. In doing so, the threat for severe weather will shift
away from the entire region. A few elevated storms cannot be ruled
out as far North as North Texas around/after midnight. Although
some small hail cannot be ruled out, the overall severe weather
threat will remain low.

Dry and cooler air will filter in tomorrow, keeping temperatures
in the upper 60s to mid 70s throughout the region. Winds will be
out of the northwest generally between 20-25. Thursday night will
be fairly cool across the region with upper 40s to lower 50s
expected.

Hernandez

&&

.LONG TERM... /Issued 317 AM CDT Wed Apr 26 2023/

Update:

We`re still looking at an active pattern through at least the
first half of the weekend. After a short break from the rain
Thursday night, showers and scattered storms will return late
Friday afternoon or evening as a cold front moves south into our
region. The only significant update made to the current forecast
is to highlight the potential for strong to severe storms Friday
afternoon and evening mainly across areas west of I-35 and south
of I-20. Latest medium-range guidance shows sufficient moisture
return (60s deg F dewpoints) coupled with decent instability and
steep lapse rates for at least an isolated severe threat as
storms move across Central Texas into Friday night. Specific
details will continue to be refined as new data becomes available!
The rest of the forecast remains in good shape.

Sanchez

Previous Discussion:
/Thursday through Tuesday/

Any lingering precipitation behind the complex of storms Wednesday
night should be quickly exiting the area by Thursday morning as
skies will briefly clear out. Thursday should be a nice day
overall with highs in the lower 70s, but low level moisture never
really gets scoured out behind this system and will begin to
spread northward Thursday night. A compact upstream shortwave will
spread into West Texas on Friday with surface pressure falls
occurring across much of the state along with a cold front racing
southward through the Plains. There remains some uncertainty with
respect to the location of the surface low and front/dryline by
Friday afternoon, but there is some potential for a quick warm
sector intrusion into North Texas, coinciding with increasing
large scale forcing for ascent. This should result in scattered
showers and thunderstorms, some of which could be severe if we do
indeed get a warm sector this far north. We`ll continue to monitor
this potential, but for now it looks like at least another quick
shot of rainfall for the region. This system will quickly move
east on Saturday with below normal temperatures expected and
perhaps some lingering light post frontal rain. A quick warmup is
expected on Sunday with highs back near 80 areawide and this trend
will continue into early next week with a generally dry forecast.
The pattern will remain active through the middle part of next
week with additional storm chances mid to late week.

Dunn

&&

.AVIATION... /Issued 549 AM CDT Wed Apr 26 2023/
/12z TAFs/

SHRA/VCTS will continue to impact D10 airports for the next 2-3
hours before a lull in convective activity occurs through the
rest of the morning. IFR cigs will prevail through midday with
uncertain improvement to MVFR through the afternoon time period.
Additional scattered convection will become possible in North
Texas as early as 18-19z, but will increase in coverage markedly
later in the afternoon/evening as a cold front approaches. The
most likely timing for convective impacts at Metroplex airports is
roughly 22-02z, and a few hours later at Waco. All convection
during this time period has the potential to be severe with
threats for hail, damaging gusts, and tornadoes. A southeast wind
will prevail outside of convective influences, but the cold front
will turn winds to the northwest at 10-20 kts following convective
activity overnight, and a breezy northwest wind with overcast
MVFR will prevail into Thursday.

-Stalley

[WhirlingWx]

25 minutes ago, cheese007 said:

FWD still seems bullish this afternoon/evening

I see nothing wrong with them continuing to be bullish, after all, our talk of a perhaps tempered threat is mostly for I-20 and north, but south of that is still within the FWD coverage area

[weatherextreme]

 

 Mesoscale Discussion 0623
   NWS Storm Prediction Center Norman OK
   0120 PM CDT Wed Apr 26 2023

   Areas affected...central TX

   Concerning...Severe potential...Tornado Watch likely 

   Valid 261820Z - 262045Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Convective initiation is forecast over central TX by mid
   afternoon coincident with the leading edge of ascent/cirrus nosing
   into the Big Country.  Additional storms may develop near the
   outflow/warm front intersection.

   DISCUSSION...Visible-satellite imagery shows a swelling cumulus
   field south of an outflow boundary and east of a dryline.  Surface
   temperatures have warmed into the lower 80s deg F with dewpoints in
   the mid 50s near San Angelo and upper 60s near the warm front. 
   Forecast soundings show minimal convective inhibition remaining
   across central TX as the boundary layer continues to
   warm/destabilize.  Water-vapor imagery shows the leading edge of
   cirrus and implied ascent spreading quickly east across the Permian
   Basin and into the Big Country.  As a result, convective initiation
   is expected in the next hour or so near Abilene.  Once the remaining
   cap is breached, expecting explosive updraft growth with a hail risk
   quickly developing.  Effective shear 40-50 kt and MLCAPE in excess
   of 3000 J/kg will rapidly promote supercell development.  Large to
   giant hail (diameters 1 to 3+ inches) is expected.  A tornado risk
   will likely focus near the warm front where relatively backed
   low-level flow augmenting hodograph size, and surface
   temperature-dewpoint spreads are less than 20 deg will reside.  A
   strong tornado may occur if an established supercell(s) can interact
   favorably with the warm frontal zone.

   ..Smith/Gleason.. 04/26/2023

[Powerball]

Today is definitely cooked for DFW.

Down towards Waco is looking good.

[Powerball]

39 minutes ago, WhirlingWx said:

I see nothing wrong with them continuing to be bullish, after all, our talk of a perhaps tempered threat is mostly for I-20 and north, but south of that is still within the FWD coverage area

 

The fact that they say Central *AND* North Texas in their AFD is kind of misleading though. It's shaping up to be a mostly Central Texas day.

[weatherextreme]

NWS Fort Worth

 

@NWSFortWorth

 

 

1:40 PM: The potential for large hail, damaging winds, and tornadoes will maximize south of I-20 this afternoon/evening. Potential for severe weather has decreased along/north of I-20, however isolated hail up to the size of quarters will still be possible. #txwx #dfwwx #ctxwx