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

[raindancewx]

I give up - March 2016 likely our ninth drier than normal March in a row.

[bubba hotep]

I give up - March 2016 likely our ninth drier than normal March in a row.

 

The Euro control run from last night was a big snowstorm for New Mexico, so you at least have that going! 

[bubba hotep]

Anybody heard of the new CASA radar in east Dallas County?

 

http://dfw.cbslocal.com/2016/03/18/new-radar-to-provide-quicker-tornado-warnings-in-east-dallas/?utm_source=TweetDal&utm_medium=twitter

 

Hopefully, no tornadoes but maybe some interesting stuff to look at on it later this week

 

[bubba hotep]

Early thinking from FWD for Wed/Thur:

 

A DRYLINE WILL
SURGE INTO THE I-35 CORRIDOR WEDNESDAY AFTERNOON. TEMPERATURES
WILL SOAR INTO THE 80S WEST OF THE BOUNDARY...WITH SOME FIRE
WEATHER CONCERNS. IN THE HUMID AIR EAST OF THE BOUNDARY...THERE
MAY BE A FEW STRONG/SEVERE THUNDERSTORMS WEDNESDAY AFTERNOON...
BUT THE MAIN EVENT STILL APPEARS TO BE LATE WEDNESDAY NIGHT INTO
THURSDAY. THERE ARE STILL INCONSISTENCIES AMONG EXTENDED GUIDANCE
WITH RESPECT TO THE EVOLUTION OF AN APPROACHING UPPER SYSTEM.
HOWEVER...THE SOLUTIONS ARE CONVERGING ON THE EARLY THURSDAY
TIMING. A LINEAR MCS WITH AN ATTENDANT WIND THREAT IS THE MOST
LIKELY STORM MODE...BUT A BRIEF WINDOW FOR PREFRONTAL NOCTURNAL
SUPERCELLS MAY OCCUR BEFORE A COLD FRONT SURGES THROUGH THE
REGION.

 

 

The 00z Euro has that streaky precipitation pattern across the DFW area but I haven't really looked that deep into the setup. 

[Quixotic1]

according to what they had yesterday to today, the triple point for Wednesday night has shifted from north Texas to northern Oklahoma.

[bubba hotep]

The 00z Euro appears to have trended towards the drier GFS solution (DFW speaking). I know the upgraded Euro is scoring better at H5 and with surface temps. However, and this anecdotally only, it seems to be struggling with precipitation vs. the old version.

 

ETA:  Latest from FWD, as always, lots of mesoscale issues will have to be worked out during the day on Wednesday:

 

MOISTURE WILL CONTINUE SURGING INTO THE REGION TUESDAY NIGHT...AT
WHICH POINT SOME WARM ADVECTION NOCTURNAL SHOWERS MAY DEVELOP. THE
GFS HAS BEEN HINTING AT THIS...AND NOW THE BEGINNING OF THIS EVENT
IS CAPTURED BY THE NAM SERIES...WHICH IS ALSO GENERATING PRECIP IN
THE 06-18Z TIME FRAME WEDNESDAY. DESPITE A GROWING MODEL
CONSENSUS...STILL THINK THIS IS OVERDONE...THOUGH A STRATUS
INTRUSION IS LIKELY WEDNESDAY MORNING. IF THE LLJ IS AS INTENSE
AND PROLONGED AS PROGGED...THE STRATUS MAY LINGER...WORKING AGAINST
BOUNDARY LAYER DESTABILIZATION LATER IN THE DAY...PARTICULARLY IF
THE SURFACE IS COOLED BY MORNING RAIN. THE STRONG 700MB FLOW AND
VEERING 850MB WINDS ARE INDICATIVE OF A DRYLINE SURGE...BUT THE
BOUNDARY MAY REACH THE I-35 CORRIDOR BEFORE MIDDAY. WITH MID-
LEVEL WINDS STRONGER NEAR THE RED RIVER THAN IN CENTRAL TEXAS...
THE DRYLINE WILL HAVE TO PIVOT CLOCKWISE AS IT MOVES THROUGH THE
REGION. ALTHOUGH THE BEST CHANCES FOR CONVECTIVE INITIATION LOOK
TO BE EAST OF THE I-35 CORRIDOR WEDNESDAY AFTERNOON...THE DRYLINE
ORIENTATION MAY ALLOW FOR SOME AFTERNOON CONVECTION IN THE
WACO/TEMPLE/KILLEEN AREA AFTER THE THREAT WOULD HAVE ENDED IN DFW
AND SHERMAN/DENISON. EVEN IF THE MORNING IS CLOUDY...CONSIDERABLE
INSTABILITY WILL BE AVAILABLE FOR ANY STORMS THAT DEVELOP ALONG
THE DRYLINE. IN ADDITION...STRONG DEEP-LAYER SHEAR WILL AID IN
STORM MAINTENANCE...KEEPING INDIVIDUAL UPDRAFTS ON THE HUMID SIDE
OF THE ADVANCING BOUNDARY. THIS IS A GOOD EXAMPLE OF TRYING TO
FORECAST MESOSCALE INTRICACIES BEYOND THE MESO TIME SCALE...THUS
THERE IS CONSIDERABLE UNCERTAINTY ABOUT HOW THINGS WILL TRANSPIRE
ON WEDNESDAY. AT THIS POINT...RESIDENTS OF NORTH AND CENTRAL TEXAS
SHOULD BE AWARE OF THE POTENTIAL FOR SEVERE THUNDERSTORMS ON
WEDNESDAY...PARTICULARLY THOSE EAST OF THE I-35 CORRIDOR.

[raindancewx]

Do we buy the mother of all rex-blocks? 

 

 

We haven't had a major March/April snow (>=3" from one storm) since March 2005, but 16 snowstorms in the last 85 years or so have delivered major snow to the city after March 1st. March 29th is actually Albuquerque's greatest snowstorm day, with four March 29ths of >=3" snow, and our greatest five day cluster for big snowstorms here is actually March 29-Apr 2.

[bubba hotep]

Slight eastward shift but still captures the eastern 1/3 of DFW

 

 

[bubba hotep]

Do we buy the mother of all rex-blocks? 

 

 

We haven't had a major March/April snow (>=3" from one storm) since March 2005, but 16 snowstorms in the last 85 years or so have delivered major snow to the city after March 1st. March 29th is actually Albuquerque's greatest snowstorm day, with four March 29ths of >=3" snow, and our greatest five day cluster for big snowstorms here is actually March 29-Apr 2.

 

Interesting, ENSO starts to cool and the monster -EPO starts to show back up. Our weather was pretty heavily influenced by the +PDO with big -EPO spikes before ENSO warmed to record levels. Wonder if we will see a return to that? I wonder what +PDO/Nina/-AMO summer looks like?

[David Reimer]

Not at all impressed with tomorrow's severe weather potential. The NAM has consistently held the cap with only post-frontal showers being indicated. West 850 MB winds will certainly reinforce the cap with temperatures in the 90s west of the dryline. 

[bubba hotep]

Do we buy the mother of all rex-blocks? 

 

12z GFS says, "Block On"

 

[raindancewx]

Interesting, ENSO starts to cool and the monster -EPO starts to show back up. Our weather was pretty heavily influenced by the +PDO with big -EPO spikes before ENSO warmed to record levels. Wonder if we will see a return to that? I wonder what +PDO/Nina/-AMO summer looks like?

 

I generally think of 1933-34, 1938-39, 1983-84, 1984-85, 1995-96 (Nov-Apr, but also July-June) as La Nina, warm PDO years. Those years were actually pretty wet in June & Sept in NM. June is kind of due to be wet, not as due as March, but it's interesting to see a wet June idea pop up. My general impression with La Nina is the monsoon starts early but is weak after a couple good early weeks. May be better to use Neutral with a warm PDO for summer though. I'm not also not entirely convinced the PDO is going to stay positive much longer. I'd probably just merge La Nina, +/= PDO, and Neutral +/= PDO for Summer, with the El Nino years that died slowly, 1941, 1982, 1997 personally.

[bubba hotep]

Latest runs of the HRRR are firing storms just to the NW of the DFW area and moving them SE, this appears to lineup pretty well with what the Euro has been showing (GFS has been trending that way). It looks like the cap will hold along the dryline and we will have to wait for the front to move in. 

[radarman]

FWIW the SPC did extend the slight risk area back westward quite a bit in the 1125 update.... now encompasses Ft Worth, whereas the previous update was entirely east of the metroplex.

[bubba hotep]

FWIW the SPC did extend the slight risk area back westward quite a bit in the 1125 update.... now encompasses Ft Worth, whereas the previous update was entirely east of the metroplex.

 

And the 5% Tor is nearly to the NE burbs of DFW. Also, the HRRR looks to be trying to fire off the dryline?

 

 

 

[bubba hotep]

12z Euro has it's most aggressive run yet across DFW this evening (given that it is now 9k, I don't really have a problem using it this close in)

[bubba hotep]

 

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1148 AM CDT WED MAR 23 2016

.UPDATE...
AN UPPER LEVEL LOW IS CURRENTLY MOVING INTO WESTERN KANSAS WITH
ITS ATTENDANT SURFACE LOW ALSO MOVING ACROSS KANSAS. A DRYLINE
EXTENDS FROM THE SURFACE LOW SOUTH...WITH THE LEADING EDGE NEAR A
VERNON TO SWEETWATER TO OZONA LINE. THE DRYLINE WILL CONTINUE
MIXING EAST...STALLING ACROSS NORTH TEXAS AROUND MID-AFTERNOON AS
THE LOWER AND MID LEVEL WINDS BECOME MORE SOUTHWESTERLY WHILE THE
UPPER LEVEL TROUGH MOVES EAST. WHERE THE DRYLINE STALLS REMAINS
THE MAIN CHALLENGE FOR THE FORECAST THE REMAINDER OF THE DAY. THE
HI RES MODELS STALL THE DRYLINE FURTHER WEST THAN PREVIOUSLY
THOUGHT AND HAVE UPDATED THE FORECAST TO REFLECT THIS CHANGE.

THE LOCATION OF THE DRYLINE AND WHERE IT STALLS WILL HAVE IMPACTS
ON THE LOCATION OF STORM DEVELOPMENT LATER TODAY. LATEST MODEL
GUIDANCE SUGGESTS THE DRYLINE WILL STALL NEAR A GAINESVILLE TO
GOLDTHWAITE LINE LATE THIS AFTERNOON. THE RAP HAS BEEN
CONSISTENTLY DEVELOPING ISOLATED CONVECTION ALONG THE DRYLINE
ALONG AND NORTH OF INTERSTATE 20 BETWEEN 22-23Z /5-6 PM CDT/ AND
NOW THE HRRR IS DEVELOPING CONVECTION TOO IN THE SAME GENERAL
LOCATION AND TIME. FORECAST SOUNDINGS FROM THE RAP SHOW THE CAP
WEAKENING ALONG THE DRYLINE ALLOWING FOR CONVECTIVE INITIATION AND
HAVE ADJUSTED THE AFTERNOON POPS ACCORDINGLY FOR THIS POTENTIAL
ALONG AND WEST OF A BOWIE TO MERIDIAN LINE. STILL KEPT THE POPS
LOW AT 20 PERCENT AS ANY STORMS DURING THE 4-6 PM TIME FRAME
SHOULD BE ISOLATED BUT THESE STORMS COULD BE SEVERE. CAPE VALUES
WILL BE BETWEEN 1500-2000 J/KG WITH STRONG BULK SHEAR VALUES. MAIN
THREATS WILL BE LARGE HAIL AND DAMAGING WINDS BUT AN ISOLATED
TORNADO WILL ALSO BE POSSIBLE.

AFTER 6-7 PM...THE COLD FRONT WILL START TO OVERTAKE THE DRYLINE
FROM NORTH TO SOUTH AND A NARROW BAND OF STORMS ALONG THE
FRONT/DRYLINE IS EXPECTED TO DEVELOP AS THIS HAPPENS. WITH THE
LIKELIHOOD THAT THE DRYLINE WILL BE WEST OF INTERSTATE
35...EXPANDED THE EVENING POPS WEST AS WELL BUT THE BEST STORM
CHANCES WILL BE ALONG AND EAST OF INTERSTATE 35. SEVERE STORMS
WILL AGAIN BE POSSIBLE WITH A THREAT FOR LARGE HAIL...DAMAGING
WINDS...AND ISOLATED TORNADOES IN THE EVENING HOURS BUT THE MAIN
THREAT MAY TRANSITION TO STRONG WINDS LATER IN THE EVENING AND
OVERNIGHT IF THE STORMS BECOME LINEAR ALONG THE FRONT...SIMILAR TO
A SQUALL LINE. OVERNIGHT...THE SEVERE THREAT WILL LOWER BUT WILL
STILL BE POSSIBLE. THE STORMS SHOULD BE EAST AND SOUTHEAST OF THE
AREA BY DAYBREAK AS THE FRONT MOVES OUT OF CENTRAL TEXAS.

DID NOT MAKE ANY CHANGES TO THE RED FLAG WARNING BUT BASED ON THE
NEW EXPECTED POSITION OF THE DRYLINE THIS AFTERNOON...HUMIDITY
VALUES WILL LIKELY BE HIGHER IN THE EASTERN COUNTIES OF THE RFW.
HOWEVER...DUE TO UNCERTAINTY IN THE EXACT LOCATION OF THE
DRYLINE...WAS NOT CONFIDENT ENOUGH TO REMOVE COUNTIES FROM THE
WARNING.

JLDUNN

[TXWXCHX]

Interesting, ENSO starts to cool and the monster -EPO starts to show back up. Our weather was pretty heavily influenced by the +PDO with big -EPO spikes before ENSO warmed to record levels. Wonder if we will see a return to that? I wonder what +PDO/Nina/-AMO summer looks like?

Bubbahotep, raindancewx: I found the following paper quite helpful regarding PDO/AMO signaling. I understand it may be out of date; however, data IS data, and the research should still stand.

PACIFIC AND ATLANTIC INFLUENCES ON MULTIDECADAL DROUGHT FREQUENCY IN THE UNITED STATES (McCabe, Palecki and Betancourt, et al, 2004)

http://www.pnas.org/content/101/12/4136.full.pdf

----EXCERPT----

FIG. 5.  Drought frequency (in percent of years) for positive and negative regimes of the PDO and AMO. (A) Positive PDO, negative AMO  (B ) PDO, negative AMO. © Positive PDO, positive AMO. (D) Negative PDO, positive AMO.

The graphic is of particular interest; I believe we can include it here as long as it is properly sourced to the original paper and authors.  The paper itself is fascinating, and I encourage anyone interested in long term forecasting/teleconnections to read it!

 

----

 

RE: today's serious wx threat: I wonder if KACT and points east will see activity overnight.  The latest AFD hints at it, but I'm trying to pin down a time frame for it...

[bubba hotep]

Bubbahotep, raindancewx: I found the following paper quite helpful regarding PDO/AMO signaling. I understand it may be out of date; however, data IS data, and the research should still stand.

PACIFIC AND ATLANTIC INFLUENCES ON MULTIDECADAL DROUGHT FREQUENCY IN THE UNITED STATES (McCabe, Palecki and Betancourt, et al, 2004)

http://www.pnas.org/content/101/12/4136.full.pdf

----EXCERPT----

pdoamo.png

FIG. 5.  Drought frequency (in percent of years) for positive and negative regimes of the PDO and AMO. (A) Positive PDO, negative AMO  (B ) PDO, negative AMO. © Positive PDO, positive AMO. (D) Negative PDO, positive AMO.

The graphic is of particular interest; I believe we can include it here as long as it is properly sourced to the original paper and authors.  The paper itself is fascinating, and I encourage anyone interested in long term forecasting/teleconnections to read it!

 

----

 

RE: today's serious wx threat: I wonder if KACT and points east will see activity overnight.  The latest AFD hints at it, but I'm trying to pin down a time frame for it...

 

That is a really good paper, I have a coffee stained copy on my desk

 

Things are coming together this afternoon

 

[Quixotic1]

I see towers starting to build off to the NW.

[bubba hotep]

I see towers starting to build off to the NW.

 

Might be what the HRRR is seeing before firing the main line later

 

[jhamps10]

Cu starting to build to my nw as well from downtown ft worth

[bubba hotep]

Temp was 78 when picking up kids and now 83 hour and half later while heading north.

[Quixotic1]

If we get anything, we should get really good views.  

[Calderon]

First cell is rising just west of Thackerville, OK on the Red River.

[NTXYankee]

First cell is rising just west of Thackerville, OK on the Red River.

It apparently wants to go gambling at Winstar first.

HRRR seems to be right again so far.

[Quixotic1]

Starting to see feeders

[JoMo]

Pampa, TX is being evacuated due to wildfire?

[bubba hotep]

 

Wonder if DFW will get a watch later on this evening?

 

[Quixotic1]

Pampa, TX is being evacuated due to wildfire?

55 mph winds! Wow.