Severe weather risk 3-26-17

[cheese007]

D1 Mod out of parts of NTX and southeastern OK. Thought it was weird that there's no thread on this conaidering the SPC threat level

[OUGrad05]

My guess is there's no thread because it's a pretty conditional setup (i.e., moisture concerns).  There is some discussion in the short range thread - FYI

This setup will continue to evolve along with the threat all day.  Small moisture deviations from the forecast can make a big difference in mode and coverage of svr storms.  Forcing appears good in OK and some supercells appear likely and could be photogenic.

[bubba hotep]

Stating the obvious here but NCAR Ens highlighting the triple point area in OK and dryline in N. TX. The HRRRx has cells as far south as DFW this evening. 

[Jim Martin]

Moisture return so far in North Texas, along with Central/Southern Oklahoma.

[Jim Martin]

60°F dewpoints now getting into Southern Oklahoma.

[nwohweather]

My guess is there's no thread because it's a pretty conditional setup (i.e., moisture concerns).  There is some discussion in the short range thread - FYI

This setup will continue to evolve along with the threat all day.  Small moisture deviations from the forecast can make a big difference in mode and coverage of svr storms.  Forcing appears good in OK and some supercells appear likely and could be photogenic.

Heck of a hail setup though. But high LCL's will more than likely inhibit a good outbreak from occurring

[OUGrad05]

Convection in SW OK might piss all over this setup

[Santa Clause]

3 minutes ago, OUGrad05 said:

Convection in SW OK might piss all over this setup

Yea, looks that way.

[andyhb]

6 minutes ago, OUGrad05 said:

Convection in SW OK might piss all over this setup

That convection is barely more than WAA showers, I don't think it's going to be too detrimental to whatever forms later.

[janetjanet998]

dewpoint now 62 at DFW and 66 at Waco...

The showers/clouds may actually help keep dews a little higher because of less mixing then 100% sunny skies.

cool 500mb temps of -17 helping too 

winds stay very backed 

moisture return is the key but it looks like there will be just enough as storms form.... because timing wise everyhting else seems right on cue

 

 

 

 

[OUGrad05]

7 minutes ago, andyhb said:

That convection is barely more than WAA showers, I don't think it's going to be too detrimental to whatever forms later.

It has failed to intensify and is moving reasonably quickly you may be right sir.

[bjc0303]

16 minutes ago, andyhb said:

That convection is barely more than WAA showers, I don't think it's going to be too detrimental to whatever forms later.

I'd argue it will help - moisture less likely to mix out. 

 

Please people

[brettjrob]

18 minutes ago, andyhb said:

That convection is barely more than WAA showers, I don't think it's going to be too detrimental to whatever forms later.

Yeah, I'll take whatever to keep the mixing in check right now lol.

[Indystorm]

Still think best tor parameters will be along the Red River at 00Z or shortly thereafter.  But we could see gigantic hail almost anywhere in the affected area.

[Santa Clause]

Hail appears to be main threat, some could be very large/destructive.

[janetjanet998]

5 minutes ago, Indystorm said:

Still think best tor parameters will be along the Red River at 00Z or shortly thereafter.  But we could see gigantic hail almost anywhere in the affected area.

my gut tells me a tail end storm may mean trouble for the northern Metroplex

[janetjanet998]

AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE FORT WORTH TX  
1218 PM CDT SUN MAR 26 2017  
   
UPDATE  
  
ONLY CHANGES TO THE SHORT TERM FORECAST THROUGH THIS AFTERNOON WAS  
TO RAISE POPS ALONG THE RED RIVER AND ADJUST THEM WESTWARD A TAD  
BASED ON LATEST HIGH-RESOLUTION GUIDANCE. THE DRYLINE IS STILL  
LOCATED TO THE WEST OF SWEETWATER BUT WINDS HAVE BEGUN TO VEER  
AHEAD OF IT SUGGESTING THAT EASTWARD PROGRESSION IS CONTINUING.  
ALL OF THE GUIDANCE SEEMS TO HANDLE THIS FAIRLY WELL MOVING THE  
DRYLINE ACROSS OUR FAR WESTERN COUNTIES BY MID AFTERNOON. TO THE  
EAST...LOW LEVEL MOISTURE HAS BEGUN TO SURGE NORTHWARD WITH 60  
DEGREE DEWPOINTS INTO THE METROPLEX AND MID-60S TO THE SOUTH. THIS  
INITIAL SURGE OF LOW LEVEL MOISTURE IS SHALLOW AND SOME MIXING IS  
EXPECTED THROUGH AFTERNOON. THE LATEST RUNS OF THE HRRR SHOW THIS  
WELL AND GENERALLY KEEP DEWPOINTS IN THE 60-62 DEGREE RANGE  
THROUGH LATE AFTERNOON, WHICH SEEMS REASONABLE. THERE IS SOME HIGH  
CLOUDINESS SPREADING IN FROM THE WEST WHICH COULD SOMEWHAT LIMIT  
VERTICAL MIXING, SO MOISTURE QUALITY REMAINS THE BIGGEST QUESTION.  
  
THE SEVERE WEATHER SETUP IS TYPICAL OF A SPRING EVENT WITH  
FORECAST SOUNDINGS SHOWING AROUND 2000 J/KG OF MLCAPE WITH LARGE,  
CLOCKWISE CURVED HODOGRAPHS IN THE LOWEST 2 KM, AND STEEP MID  
LEVEL LAPSE RATES. THIS SUGGESTS ALL MODES OF SEVERE WEATHER WILL  
BE POSSIBLE. AS OF THIS AFD, THE THREAT FOR VERY LARGE HAIL   
REMAINS THE BIGGEST CONCERN, ESPECIALLY WITH THE INITIAL   
DEVELOPMENT. THE TORNADO THREAT WILL BE DEPENDENT UPON THE QUALITY  
OF MOISTURE RETURN THROUGH THE AFTERNOON. IF EXTENSIVE MIXING   
OCCURS, KEEPING DEWPOINTS IN THE UPPER 50S THEN THE THREAT FOR   
TORNADOES WOULD BE SOMEWHAT LOWER GIVEN THE HIGHER STORM BASES. IF  
MOISTURE RETURN IS MORE ROBUST AND LIMITED MIXING OCCURS, THEN   
THE TORNADO THREAT WOULD INCREASE. WE WILL SEND UP AN EXTRA   
BALLOON THIS AFTERNOON TO ASSESS THIS POTENTIAL. EITHER WAY, THERE  
WILL BE A THREAT FOR TORNADOES WITH THIS EVENT WELL INTO THE   
EVENING HOURS. THIS THREAT SHOULD BE HIGHEST ALONG THE RED RIVER.  

[OUGrad05]

Convection ramping up now down by OKC, I think this is too early

[Stebo]

Just now, OUGrad05 said:

Convection ramping up now down by OKC, I think this is too early

This is convection associated with the moisture advection, this isn't the main event.

[janetjanet998]

Just now, OUGrad05 said:

Convection ramping up now down by OKC, I think this is too early

elevated WAA type ....not the main show..on the

 leading edge of higher moisture return

[Upper Level LOL]

1 minute ago, OUGrad05 said:

Convection ramping up now down by OKC, I think this is too early

It's super thin, sun still peeking through

[OUGrad05]

6 minutes ago, Stebo said:

This is convection associated with the moisture advection, this isn't the main event.

I know it's not the main threat, the issue is that it puts down cold pools or stabilizes the atmosphere and it wasn't that destabilized to begin with

[Stebo]

Just now, OUGrad05 said:

I know it's not the main threat, the issue is that it puts down cold pools or stabilizes the atmosphere and it wasn't that destabilized to begin with

It isn't that vigorous and is moving away from the region where the main show will be while adding moisture. The destabilization is associated with the moisture advection and the cooling aloft moving in, the surface won't be stabilized by these showers.

[brettjrob]

These lead showers/storms might be starting to get slightly out of hand - at least, they're not ideal, at this point. Light showers (30 dBZ) are fine, but some of these cells might mix down momentum from aloft that's detrimental to SRH (i.e., promote veering of flow right near the ground). Fortunately, any downdrafts intense enough to do that are fairly sparse, for the moment.

[bjc0303]

I'm really not seeing anything to significantly hamper storm/tor potential 

[OUGrad05]

I just disagree, hell one of them is SVR warned at this point and you don't think that'll impact the atmosphere especially at lower levels?  I don't see how it won't at this point.  But I'm probably wrong.

[janetjanet998]

 
MESOSCALE DISCUSSION 0333  
NWS STORM PREDICTION CENTER NORMAN OK  
0124 PM CDT SUN MAR 26 2017  
  
AREAS AFFECTED...CENTRAL OK  
  
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY   
  
VALID 261824Z - 261930Z  
  
PROBABILITY OF WATCH ISSUANCE...20 PERCENT  
  
SUMMARY...ISOLATED HAIL IS POSSIBLE ACROSS CENTRAL OK THROUGH EARLY  
AFTERNOON. A MORE ROBUST SEVERE THREAT IS ANTICIPATED LATER THIS  
AFTERNOON.  
  
DISCUSSION...RECENT RADAR AND SATELLITE TRENDS HAVE SHOWN AN  
INCREASE IN ELEVATED CONVECTION OVER THE LAST HOUR. THIS ACTIVITY  
INITIATED NEAR THE LEADING EDGE OF THE INCREASING LOW TO MID-LEVEL  
MOISTURE  (DEPICTED WELL BY THE MESOANALYSIS AT 850 MB) AND APPEARS  
TO BE ROOTED SOMEWHERE BETWEEN 700 AND 800 MB. GRADUALLY INCREASING  
MID-LEVEL FLOW COUPLED WITH STEEP MID-LEVEL LAPSE RATES WILL LIKELY  
RESULT IN SOME MODEST ORGANIZATION OF THESE STORMS, WHICH COULD  
RESULT IN ISOLATED INSTANCES OF SEVERE HAIL. HOWEVER, THESE STORMS  
WILL MOVE NORTHEASTWARD INTO A LESS FAVORABLE THERMODYNAMIC  
ENVIRONMENT, SUGGESTING STRONGEST UPDRAFTS MAY NOT PERSIST BEYOND  
THE NEXT HOUR OR TWO. A MORE ROBUST, SURFACE-BASED THREAT IS  
EXPECTED DURING THE LATE AFTERNOON FARTHER SOUTHWEST NEAR THE I-44  
AND I-35 CORRIDORS.  

[OUGrad05]

We're still targeting OKC Metro area, but I don't like this convection, if I were in OKC or DFW I'd still be targeting red river area, less impact by ongoing convection and better parameters anyway....still hoping for some good photos today

[Stebo]

6 minutes ago, janetjanet998 said:

 
MESOSCALE DISCUSSION 0333  
NWS STORM PREDICTION CENTER NORMAN OK  
0124 PM CDT SUN MAR 26 2017  
  
AREAS AFFECTED...CENTRAL OK  
  
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY   
  
VALID 261824Z - 261930Z  
  
PROBABILITY OF WATCH ISSUANCE...20 PERCENT  
  
SUMMARY...ISOLATED HAIL IS POSSIBLE ACROSS CENTRAL OK THROUGH EARLY  
AFTERNOON. A MORE ROBUST SEVERE THREAT IS ANTICIPATED LATER THIS  
AFTERNOON.  
  
DISCUSSION...RECENT RADAR AND SATELLITE TRENDS HAVE SHOWN AN  
INCREASE IN ELEVATED CONVECTION OVER THE LAST HOUR. THIS ACTIVITY  
INITIATED NEAR THE LEADING EDGE OF THE INCREASING LOW TO MID-LEVEL  
MOISTURE  (DEPICTED WELL BY THE MESOANALYSIS AT 850 MB) AND APPEARS  
TO BE ROOTED SOMEWHERE BETWEEN 700 AND 800 MB. GRADUALLY INCREASING  
MID-LEVEL FLOW COUPLED WITH STEEP MID-LEVEL LAPSE RATES WILL LIKELY  
RESULT IN SOME MODEST ORGANIZATION OF THESE STORMS, WHICH COULD  
RESULT IN ISOLATED INSTANCES OF SEVERE HAIL. HOWEVER, THESE STORMS  
WILL MOVE NORTHEASTWARD INTO A LESS FAVORABLE THERMODYNAMIC  
ENVIRONMENT, SUGGESTING STRONGEST UPDRAFTS MAY NOT PERSIST BEYOND  
THE NEXT HOUR OR TWO. A MORE ROBUST, SURFACE-BASED THREAT IS  
EXPECTED DURING THE LATE AFTERNOON FARTHER SOUTHWEST NEAR THE I-44  
AND I-35 CORRIDORS.  

Other than the far northern one, most of the stuff is already weakening. Even that northern one should be on a downturn soon.

[Hoosier]

7 minutes ago, OUGrad05 said:

I just disagree, hell one of them is SVR warned at this point and you don't think that'll impact the atmosphere especially at lower levels?  I don't see how it won't at this point.  But I'm probably wrong.

On a localized level, yes.  Should be temporary though assuming no additional development in the near term.  We're not talking about a well organized MCS throwing down a significant cold pool.