Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 7

[bubba hotep]

The GFS predicts pretty decent CAPE and shear ahead of the advancing dryline on Monday. This could kick off several discrete storms with 0-6km shear of around 45kts. We'll have another 3 days of model runs before this happens.

 

 

Kind of reminds me of the setup from a couple of weeks ago when the models kept insisting on the dryline surging east during the day and being east of I35 pretty early on. Then the dryline got hung up west of DFW and svr storms fired and moved through with a brief tornado and widespread damaging hail. The trend on the Euro EPS has been to slow things down, so it will be interesting to watch. Since I've moved to the area, it seems like the dryline gets hung up west of DFW more often than it moves east of I35 during the day, this is purely anecdotal and I don't have any data to back that up. 

[Roy]

I love being here compared to West Texas largely since the dryline is actually west of us a lot. Hated how it always would set up a few counties east of me when I lived in Midland. 

[bubba hotep]

The Euro weeklies continue to look wet into May, the control run would probably be a return to flooding with areas of N. Texas at 15"+ of rain  Something interesting, from just glancing through the data, it looks like when April & May combine for 10" or more of rain at DFW there is a good chance that the yearly total goes above 40". I might feed the data to my stat software tonight, if I'm up for late night baby duty. That would give DFW back-to-back years of 40" or more. It looks like that has only happened 3 other times, with data going back to 1898. 

[bubba hotep]

Still looks to be dryline timing issues, but FWD is more confident with the timing of this event:

 

 

FOR MONDAY...THE SHARPENING DRYLINE SHOULD CONTINUE TO MIX
EASTWARD AS STRONG FORCING CONTINUES TO OVERSPREAD PORTIONS OF
OKLAHOMA AND NORTH TEXAS. WHILE THE MODELS HAVE BEEN OVERLY
AGGRESSIVE DURING THE PAST SEVERAL ROUNDS OF SEVERE WEATHER WITH
RESPECT TO THE LOCATION OF THE DRYLINE...CONFIDENCE IS A BIT
HIGHER THAT THEY HAVE A GOOD HANDLE ON ITS PLACEMENT ON MONDAY.
THERE ARE A COUPLE OF REASONS FOR THIS. ONE...IT APPEARS THAT THE
LOCATION OF THE MAIN SYNOPTIC SCALE LIFT WILL BE A BIT CLOSER TO
OUR REGION WHICH SHOULD HELP TO PUT THE TRACK OF THE SURFACE LOW
CLOSER TO THE RED RIVER. TWO...25 TO 35 KNOT WESTERLY FLOW JUST
ABOVE THE SURFACE THAT IS INDUCED BY THE DEEPENING LOW SHOULD BE
MIXED DOWNWARD TOWARDS THE SURFACE. THIS MIXING PROCESS SHOULD
HELP THE DRYLINE TO PROPAGATE TO THE EAST FAIRLY EFFICIENTLY AND
AT THIS TIME...WE EXPECT THAT IT WILL BE NEAR THE I-35 CORRIDOR
BY MONDAY AFTERNOON. OF COURSE...IF THE ABOVE THINKING DOES NOT
HOLD TRUE /I.E. PLACEMENT OF THE SURFACE LOW AND MIXING/ THEN THE
DRYLINE MAY REMAIN FURTHER WEST THAN CURRENT MODEL INDICATE.

WITH REGARDS TO THE PRECIPITATION CHANCES ON MONDAY...A LARGE CAP
DOES APPEAR TO REMAIN ON MONDAY AFTERNOON FOR AREAS EAST OF THE
DRYLINE. CONTINUED TRANSPORT OF WARM AND MOIST AIR COMBINED WITH
SYNOPTIC SCALE ASCENT SHOULD HELP TO WEAKEN THIS FEATURE. IN
ADDITION...ANY LOCALIZED AREAS OF CONVERGENCE ALONG THE DRYLINE
WOULD ALSO BE A FAVORABLE LOCATION FOR THE INITIATION OF DEEP
MOIST CONVECTION. RIGHT NOW...HAVE LEFT CHANCE POPS AS THERE
REMAINS TOO MUCH UNCERTAINTY AS TO THE STRENGTH OF THE CAP. IF
STORMS ARE TO BREACH THE CAP...THEY WILL HAVE THE POTENTIAL TO
REALIZE A FAIRLY UNSTABLE ATMOSPHERE CHARACTERIZED BY 1500-2000
J/KG OF CAPE AND DEEP LAYER SHEAR VALUES ON THE ORDER OF 40 TO 50
KNOTS. THESE VALUES OF DEEP LAYER SHEAR JUXTAPOSED WITH STEEP
LAPSE RATES WILL SUPPORT A LARGE HAIL AND DAMAGING WIND THREAT.
WHILE LCLS SHOULD REMAIN LOW...SURFACE WINDS APPEAR TO BE
SLIGHTLY VEERED WHICH COULD LIMIT A MORE APPRECIABLE TORNADO RISK
MONDAY AFTERNOON. IF WINDS BACK SLIGHTLY...THIS WOULD CERTAINLY
RESULT IN A GREATER DEGREE OF LOW LEVEL CURVATURE AND WOULD
WARRANT A HIGHER TORNADO RISK. FOR NOW...WE WILL ADVERTISE LARGE
HAIL AND DAMAGING WINDS AS THE MAIN HAZARDS FOR MONDAY/S EVENT.

[bubba hotep]

Go showers go! Fading storms moving in

 

[Quixotic1]

So, I'm fertilizing the lawn (literally with Scott's weed n feed) about 15 minutes ago (don't ask) and was scared to death by a sudden bolt of lightning. Thought we were done for the night.....

[bubba hotep]

So, I'm fertilizing the lawn (literally with Scott's weed n feed) about 15 minutes ago (don't ask) and was scared to death by a sudden bolt of lightning. Thought we were done for the night.....

 

I did mine back before the time change, had a headlamp on pushing the spreader. Wife was not happy about that  

[bubba hotep]

Euro fires some storms early in the day that drag across the northern burbs. If the dryline is slower, by even a few hours, then things could be a little more interesting.

 

[Quixotic1]

I did mine back before the time change, had a headlamp on pushing the spreader. Wife was not happy about that

The wife and kids are gone this weekend. So wild that I'm out fertilizing the yard. Haha.

Seriously the dry level must be something else because I've been hearing peals of thunder since I've come in. There is nothing falling out there.

[Msalgado]

The combination of no real chases yet this season and the conditions near Childress being even better with each model run I will likely make the trip out there from CLL tomorrow.  

[bubba hotep]

The combination of no real chases yet this season and the conditions near Childress being even better with each model run I will likely make the trip out there from CLL tomorrow.  

 

HPC is now on board

 

[raindancewx]

It's interesting playing around with last snowfall dates in Albuquerque - we seem to be at the cyclical low point for "last snowfall" on a decadal basis. Lots of things favoring March/April snow do seem due to come - better rains in August, colder AMO, normal snow in March.

 

[bubba hotep]

Interesting to see what becomes of the storms firing down SW of DFW. I don't think any model had that? Sneaky little disturbance lifting the cap or just some short lived elevated trash?

[Msalgado]

It's interesting playing around with last snowfall dates in Albuquerque - we seem to be at the cyclical low point for "last snowfall" on a decadal basis. Lots of things favoring March/April snow do seem due to come - better rains in August, colder AMO, normal snow in March.

 

Its probably the PDO.

 

EDIT:  And after 1980 in addition to the PDO you should see a climate change signal there too since about 1980 is when NM melt season temps go through the roof.

[bubba hotep]

Man, the HRRR has been all over the place today

[Msalgado]

Pretty good first chase this year.  No tornadoes, but some great lightning pictures and I think I have some good structure shots.  Will need to review them and do my edits.

[bubba hotep]

Looks like we might see some action this morning after all.

[Quixotic1]

lot of lightning and rain in this morning's storms. 

[NTXYankee]

Will be interesting to see if it verifies but the latest runs of the HRRR slows the dryline down, fires storms west of metroplex and moves them through around 20z.

 

Edit:  Interestingly enough the 12Z NAM and 4K NAM have come in slower with dryline as well not blowing it through here at all and remains west of metroplex.  Hmm, maybe some revisions on that SPC forecast?

[Calderon]

Will be interesting to see if it verifies but the latest runs of the HRRR slows the dryline down, fires storms west of metroplex and moves them through around 20z.

 

Edit:  Interestingly enough the 12Z NAM and 4K NAM have come in slower with dryline as well not blowing it through here at all and remains west of metroplex.  Hmm, maybe some revisions on that SPC forecast?

Yeah, I just mentioned that in the today-specific thread. I work for Southwest as a supervisor at Love Field and will be keeping a very close eye on things today. 

[bubba hotep]

Surface obs clearly show the dryline still west of DFW and the triple point could pass pretty close this afternoon:

 

[bubba hotep]

Update from FWD:

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1107 AM CDT MON APR 11 2016

.UPDATE...
MAIN CONCERN IN THE SHORT TERM CONTINUES TO BE THE SEVERE
THUNDERSTORM POTENTIAL FOR THIS AFTERNOON AND EVENING OVER
PORTIONS OF NORTH CENTRAL TEXAS. WHILE THUNDERSTORM COVERAGE IS
NOT EXPECTED TO BE WIDESPREAD TODAY THUNDERSTORMS THAT DO DEVELOP
WILL HAVE THE POTENTIAL TO BE SEVERE. WE HAVE SLIGHTLY MODIFIED
THE SEVERE WEATHER POTENTIAL AREA TO BE A BIT FURTHER WEST AND
SOUTH AS A SURFACE LOW IS PROGGED TO TRACK ACROSS NORTH TEXAS
AND COMBINE WITH AN APPROACHING DRY LINE AND ALSO A COLD FRONT AND
SOME REMNANT OUTFLOW FROM THIS MORNINGS STORMS ALONG THE RED
RIVER. OUR MAIN AREA OF CONCERN IS FOR ISOLATED TO SCATTERED
SEVERE STORMS PRIMARILY NORTH OF I-20. A SECONDARY BUT MORE
ISOLATED POTENTIAL EXISTS SOUTH OF I-20 AND ALONG AND EAST OF I-35.
THIS DOES INCLUDE THE POSSIBILITY FOR SEVERE STORMS OVER THE
METROPLEX WITH A SMALLER POSSIBILITY THE FURTHER SOUTH YOU GO
TOWARDS WACO.

HOETH

 

ETA: Updated Graphic 

 

[bubba hotep]

lot of lightning and rain in this morning's storms. 

 

And they left boundaries all over the place... 

[bubba hotep]

FWD sending up an extra balloon here in a few minutes.

[NTXYankee]

Update from FWD:

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE FORT WORTH TX

1107 AM CDT MON APR 11 2016

.UPDATE...

MAIN CONCERN IN THE SHORT TERM CONTINUES TO BE THE SEVERE

THUNDERSTORM POTENTIAL FOR THIS AFTERNOON AND EVENING OVER

PORTIONS OF NORTH CENTRAL TEXAS. WHILE THUNDERSTORM COVERAGE IS

NOT EXPECTED TO BE WIDESPREAD TODAY THUNDERSTORMS THAT DO DEVELOP

WILL HAVE THE POTENTIAL TO BE SEVERE. WE HAVE SLIGHTLY MODIFIED

THE SEVERE WEATHER POTENTIAL AREA TO BE A BIT FURTHER WEST AND

SOUTH AS A SURFACE LOW IS PROGGED TO TRACK ACROSS NORTH TEXAS

AND COMBINE WITH AN APPROACHING DRY LINE AND ALSO A COLD FRONT AND

SOME REMNANT OUTFLOW FROM THIS MORNINGS STORMS ALONG THE RED

RIVER. OUR MAIN AREA OF CONCERN IS FOR ISOLATED TO SCATTERED

SEVERE STORMS PRIMARILY NORTH OF I-20. A SECONDARY BUT MORE

ISOLATED POTENTIAL EXISTS SOUTH OF I-20 AND ALONG AND EAST OF I-35.

THIS DOES INCLUDE THE POSSIBILITY FOR SEVERE STORMS OVER THE

METROPLEX WITH A SMALLER POSSIBILITY THE FURTHER SOUTH YOU GO

TOWARDS WACO.

HOETH

ETA: Updated Graphic

I thought Ohio weather changed on a dime, seems pretty frequent here too.

[Calderon]

An oddly enough the SPC actually trimmed the threat a bit further east. 

[bubba hotep]

There appears to be subtle boundary hanging out from around Irving across Dallas up towards Farmersville, showers and storms keep firing and moving NE along it. Shows up pretty nicely in the 1-min radar scans. Then there is the more obvious boundary up towards the Red River. Also, sun is starting to peak through here in Collin County. 

[bubba hotep]

An oddly enough the SPC actually trimmed the threat a bit further east. 

 

Saw that. Then the latest HRRR run really fires the dryline just west of DFW in a few hours. 

 

[bubba hotep]

[bubba hotep]

Looks like a watch coming shortly:

 

 

MESOSCALE DISCUSSION 0363
NWS STORM PREDICTION CENTER NORMAN OK
1239 PM CDT MON APR 11 2016

AREAS AFFECTED...NRN TEXAS AND PARTS OF ADJACENT SRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 111739Z - 111945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A WATCH LIKELY WILL BE NEEDED ACROSS NORTH TEXAS AT SOME
POINT THIS AFTERNOON...PROBABLY BY 20-21Z...PERHAPS EARLIER.

DISCUSSION...THE RAPID REFRESH SUGGESTS THAT INHIBITION FOR MOIST
BOUNDARY LAYER PARCELS IS IN THE PROCESS OF WEAKENING...IN RESPONSE
TO INSOLATION...AND THE ONSET OF WEAK MID-LEVEL COOLING ACROSS
NORTHWEST INTO NORTH CENTRAL TEXAS. THIS IS GENERALLY TO THE SOUTH
OF A SLOWLY SOUTHWARD ADVANCING COLD FRONT...AND A STALLING
CONVECTIVE OUTFLOW BOUNDARY.

TOWARD AND AFTER 20-21Z...STRONGEST DESTABILIZATION IS EXPECTED TO
BECOME FOCUSED JUST EAST OF A DEVELOPING SURFACE LOW NEAR THE
INTERSECTION OF THE OUTFLOW BOUNDARY...AND AN EASTWARD ADVANCING
DRYLINE...NEAR AND NORTH THROUGH EAST OF THE DALLAS/FORT WORTH
METROPLEX. BENEATH AT LEAST MODEST STEEP MID-LEVEL LAPSE
RATES...MIXED LAYER CAPE PROBABLY WILL EXCEED 2000 J/KG.

ALTHOUGH WIND FIELDS AROUND 850 MB HAVE ALREADY WEAKENED AND VEERED
TO A PRONOUNCED WESTERLY COMPONENT...40-50 KT WESTERLY 500 MB FLOW
WILL PROVIDE SUFFICIENT VERTICAL SHEAR FOR ORGANIZED SEVERE STORMS.
GIVEN THE MAGNITUDE OF INSTABILITY...THIS PROBABLY WILL INCLUDE
INTENSIFYING SUPERCELL STRUCTURES. THIS SEEMS MOST LIKELY LATE THIS
AFTERNOON...AIDED BY FORCING FOR ASCENT ASSOCIATED WITH AN UPPER
IMPULSE TURNING EAST SOUTHEAST OF THE TEXAS PANHANDLE REGION.
HOWEVER...AN INCREASE IN STORM DEVELOPMENT ALREADY IS ONGOING NEAR
THE RED RIVER...PROBABLY ROOTED WITHIN WARM ADVECTION ABOVE THE
BOUNDARY LAYER. AND IT IS POSSIBLE THAT UPPER FORCING COULD SUPPORT
ADDITIONAL STORM DEVELOPMENT WITH AT LEAST A RISK FOR SEVERE HAIL
ACROSS PARTS OF NORTHWEST TEXAS INTO SOUTHWESTERN/SOUTH CENTRAL
OKLAHOMA WITHIN THE NEXT COUPLE OF HOURS.

..KERR/GOSS.. 04/11/2016


ATTN...WFO...SHV...FWD...OUN...SJT...