When comparing the default, LMA1 and LMA2 color tables for viewing the PGLM lightning data, I found that I don’t really like any of them. All three images below show the PGLM data at 1942Z using the various color table options. The highest pixels (58 & 53) in the northern storm show up as the the gray/green colored pixels which are in the center of the default color curve. I would have assumed that the bolder blue hues would have been the higher values in this case, which is why I don’t care for the default color table. For the same reason, I don’t like LMA1 or LMA2 either. Improving the color table will be important moving forward with this product.

Default

LMA1

LMA2

-Helen Hunt

Probsevere jumped to near 70% with this storm.  Large core of 50+ dBz at 30kft.  The -30 is around 24kft based on the LBF sounding.  There was also a jump in lightning according to the ENI timeseries and data.  Decided to issue a warning for this storm.

MacGyver

A prodigious lightning producer early developing north of Cheyenne has a CIMSS indicated prob severe nearly 90 percent.  The cell is exhibiting strong inflow along with sustained high lightning levels as shown by the GLM Mapper, PGCO Surface Flash Density regional mapper and MRMS Verically Integrated Ice (click second image for loop).

John Pendergrast

CIMSS products were helpful in determining which portions of the FA are most favorable for convection. The CIMSS PWAT, CAPE, LI, and SI values are all most favorable in the northeastern quadrant. CAPE is up to 2200 J/kg, LI values up to -7 and PWAT up to 1”. My initial analysis of only the CIMSS products is consistent with the SPC Day 1 Categorical Outlook which shows a slight risk over the eastern part of the FA and only a marginal and general area further south and west. 0-6 km bulk shear is also most favorable in the east/northeast quadrant with values up to 40 knots. This shear is sufficient to promote organized convection including supercells. The main threats today will be wind, hail and even tornadoes.

-Helen Hunt

These gravity waves should lead to an interesting afternoon across the GID CWA.  The one min ssro data is EXTREMELY useful and helpful with trying to figure out what is going on.  I think these waves may lead to some CI or storm intensificationlater today.

MacGyver

While monitoring the cell as it shifted SE out of Brantley county, which also had large amounts of total lightning for several volume scans, I noticed that an inflow notch had begun to develop on the backside of the storms.  Having taught many SKYWARN sessions for our CWA, I knew this was indicative of a low level inflow jet working into the storms.  I also noticed that the low level SRM was increasing.  When you see the loop of both the 0.5 degree reflectivity and SRM, you will see the bulge working south out of the storms.  Based on this, I issued an SVR for northwestern Camden county at 730 PM EDT, expiring at 815 PM.

WFO JAX received a spotter report of a tree down due to strong thunderstorm winds at 755 PM EDT one mile N of Tarboro.  Verified!

CoonieCatEye

Saw a rapid increase in pGLM Flashes(106/1min) and then witnessed a very strong increase in reflectivity and supercell with a hook appendage. This definitely got my attention and ended issuing a SVR for it. –Cattywampus

Fig 1: (Gif loop) Rapid pGLM increase in NE Douglas.

Fig 2:  (Gif loop) Subsequent supercell development. Loop to long (sorry) its the last warning in the series.

I noticed a very dramatic increase in lightning activity and prob severe as a storm approached the Jacksonville FA (from Lanier County), so I decided to go ahead and pull the trigger on a severe thunderstorm warning. The prob severe didn’t quite make it to the 80% threshold (only 78%), but since it accompanied the ‘lightning jump’, my confidence was higher that it was intensifying and was capable of producing severe weather. There was also an overshooting top associated with this storm as seen by the overshooting top detection.

The warning has not verified yet. (Click image to see animation)

-Helen Hunt

The persistent cell over eastern Kansas shows good evidence of strong updrafts on the shadowed 1 minute imagery.  Deep convection with good evidence of rotation on radar imagery likely is producing severe hail.  CIMSS algorithm currently shows 99 percent likelihood of severe with hail size hear 2 inches.

John Pendergrast