Increasing trend in Prob Severe products

Between 1840Z and 1844Z, the ProbWind increased from an already high level of 85% to 84% as a bowing segment developed and moved into northern Brazos and Madison Counties.  Also of small note, ProbHail increased from 15% to 29%, and ProbTor increased from 17% to 20%.





ZDR_Arcophile

ProbSvr with MDA, DMDA, and NMDA

Loop from KAMA of legacy MDA (top left), DMDA (top right), NMDA (bottom left) with ProbSevere overlaid on the velocity data.

Minimum Flash Area Shows all the Features

As we move towards sunset, the MCS continues to munch across the southeast Tejas, Louisiana, and portions of Arkansas.  There is alos a strong storm developing ahead of the MCS in SE Louisiana.  Add in some storms across Northwest OK and there is whole spectrum of flash sizes is showing up now:



What is neat about this image is that the small flashes (purple) are concentrated near the overshooting tops of the storms.  The  large area flashes (red to white) are in the trailing stratiform area.
One other cool tidbit I just saw in this loop; watch the southwestern part of the line where a storm weakens and dissipates; flash area basically shows that all electrical activity ceases along with the storm.  Looking closer:



-Dusty

Using ProbSevere Time Series for Situational Awareness

A particular storm in the CWA, which had previously been quite strong, had weakened and I diverted my attention elsewhere. However, I kept the ProbSevere Time Series displayed on another monitor. Later, I noticed that the Time Series indicated that the storm was potentially re-intensifying  (top left image) and it caused me to direct my attention back to the thunderstorm.

ProbTOR in Stratiform Rain???

Here is an example where the ProbSevere algorithm identified an area of concern in heavier stratiform rain. ProbTOR values peaked around 12% in this area. This is a good reminder that YMMV when using ProbSevere.

The Life and Death of a Gulf Storm Through the Eyes of Experimental Products

In this case of a rapidly developing storm, GLM data was leaned on to issue a SVR Warning on what otherwise may have been a marginal storm. AllSkyLAP showed the storm was developing in an area of MLCAPE values over 2000 J/kg, and ProbWind model had rapidly increased to ~50%. GOES-16 1-minute imagery showed rapidly cooling cloud tops, with a sharp increase in lightning activity. Given GLM values comparable to other severe storms on the day a SVR warning was placed on the storm. The warning was sent out relatively early to try to capitalize on lead time.

Radar w/ ProbSevere:


IR-Sandwich:


Flash Event Density:


Minimum Flash Area:


Event Density:

Total Optical Energy (too fast, whoops!):


AllSkyLAP CAPE:


ProbWind Model Increase:


UPDATE: Shortly after warning on the storm, it completely fell apart after failing to become rooted in the boundary layer and all indicators (i.e., ProbSevere, GLM imagry) dropped to null. Initial warning was shamefully cancelled.
Really living up up to my name!

Radar w/ProbSevere:


Flash Event Density:


ProbWind Model Increase:



#ProtectAndDissipate

Six Hours Later - Same Surging in All-Sky LAP TPW

At 2127 and 2157 UTC on 8 May (exactly six hours after it was previously noted), a surge in TPW in a cloudy region (Northeast TX region).  This might be a predictable behavior in All-Sky LAP and points to improvement needed in how it handles new model cycles.  Similar jump behavior was noted in All-Sky LAP CAPE.

                2127 UTC                                  2157 UTC



JohnF.

ProbSevere & Satellite Imagery

Although ProbSevere products are typically used coincident with radar data, but can also be applied to satellite imagery. Using ProbSevere with satellite imagery can provide a visualization as to where the strongest parts of a thunderstorm may be located.

This loop shows developing & strengthening convection across the Texas Panhandle and far western Oklahoma, via Day Cloud Phase imagery with ProbSevere overlaid.

Situation Awareness using AllSkyLAP CAPE gradient

As a good tool for a mesoanalyst, the enhanced gradient for CAPE within AllSkyLAP would indicate an area of focus for discrete convection forming along the southwest flank of the line of convection that fizzled earlier. This area would be a place to focus for future possible convection.



ZDR_Arcophile

Comparison of Modified NUCAPS

In trying to give due diligence to all of the products I decided to look at the NUCAPS soundings a little deeper today. The location of the sounding point was around 9 mi SE of Ruston Regional Airport in an area that was impacted by a weak line of convection moving across central Louisiana, as shown in the METARS from KRSN.


Both soundings passed the QC checks and were towards the center of the swath. So what did NUCAPS show? Here are the lowest levels of both the NUCAPS and Modified NUCAPS soundings at 19Z...

NUCAPS Sounding at 19Z

Modified NUCAPS Sounding at 19Z

The NUCAPS sounding had a temp of 21.92C (71.47F) and a dew point of 16.18C (61.12F). The modified NUCAPS sounding had a temp of 20.81C (69.46F) and a dew point 17.72 C(63.87F).

For comparison here are the RTMA temp and dew point between 17-19Z at the sounding point and at KRSN...
T/Td @ NUCAPS                  T/Td @ KRSN
17Z           72.65F                                       72.76F
18Z           73.68F/69.49F                     74.08F/69.39F
19Z           71.47F/69.93F                     73.10F/70.40F

It makes sense that the RTMA dew point depression is small given the recent rains, and if the RTMA is suppose to be the ground truth,  it looks like the NUCAPS soundings did a bad job in this case.

Temps for the NUCAPS soundings were 2-4 degrees cooler which is okay, but the modified sounding was cooler. It would have probably been better to keep the temp from the unmodified sounding. With regards to dew points, both the modified and unmodified soundings had lower dew points than RTMA, on the order of 6-7 degrees. These definitely affected the thermodynamic calculations, though I'm pretty positive that it was the mid-level inversion that did the most damage. I'm not sure how to fix this since only the surface points get modified.

Anyways, hindsight being 20/20, I probably should have looked at an area that wasn't recently impacted by rain, but by the time I realized it it was too late and I already gathered all the data. Anyways, both NUCAPS soundings in this case did not accurately represent the environment in the lower levels, likely a result of evaportaive cooling and outflow behind the line of convection. This is a word of caution that despite the soundings passing the QC checks (the points were both green) and being in the center of the swath the data may not be the most useful.