Adjusted NUCAPS Sounding for far north central MS at 1800 UTC - Helpful with estimating CAPE!

Below is an adjusted NUCAPS sounding from far north central MS at 1800 UTC. After adjusting the low level temperature and dew point temperature profiles, CAPE values aroun 420 J/kg were seen on the NUCAPS sounding. This gave valuable information on the amount of CAPE across the area just ahead of the advancing pre-frontal trough. This would suggest that there is potential for further convective development in this area over the next few hours. JJW

Prob. Severe w/ Handling Cells Among an Ordinary Rain Reflectivity Field

I am still continuing to monitor the KMFL CWA today for any severe thunderstorm development, though for the most part, conditions are not favorable for that kind of development today.

However, unlike the rest of this week when we had just individual thunderstorms cells, the Prob. Severe Algorithm is handling the individual stronger cells very well within the other ordinary, non-thunderstorm rain field.

-BW

Lightning Jump and ProbSevere doing well in "messy" environment

Note: The CG Lightning Probability product is not a GOES-R or JPSS funded project.

A mess of thunderstorms with plenty of lightning is currently making its way across southern Floriday this afternoon. ProbSevere is doing a good job picking up on the convective cells...even in a "messy" environment. In fact...both the Sigma Lightning Jump and CG Lightning Probability also did well in pinpointing individual objects...even over the open ocean.

MRMS Composite Reflectivity (Top Left), MRMS VII iwth Lightning Jump overlaid (Top Right), SRSOR Parallax-Corrected Visible Imagery with ProbSevere overlaid (Bottom Left), CG Experimental Lightning Probability Scale with ENI Total Lightning Cloud to Ground and Cloud Flashes overlaid (Bottom Right)

For example...the cell near Princeton has a 45% ProbSevere Probability corresponding with a 3.0 Sigma Lightning jump and a 93% CG Lightning Probability (20 fl/min) at 1838Z. That cell in particular increased from 35% ProbSevere and 78% CG Prob (with 11 fl/min) at 1834Z to to those higher values in 4 minutes. However, in this situation...the CG Lightning Probability isn't providing much lead time...if at all.

~Lilly Miller~

1-Minute SRSOR Imagery Features Compared to Radar Imagery - Cool Stuff!

Below is the 1-minute SRSOR visibile imagery over the far eastern part of Memphis' CWA at 1834 UTC. The cursor readout is highlighting one of several areas of brighter white cloud tops being detected, mainly in southern Gibson, Carroll and Benton Counties. These features suggest these cells have the highest cloud tops, compared to the others in the area.

The corresponding radar imagery from KNQA at 1834 UTC shows where the showers and isolated thunderstorms have developed. The higher radar echoes below correspond very well to the brighter clouds being detected in the 1-minute imagery above. This is a very cool way to track these cells! These features on the 1-minute imagery, such as the brighter clouds shown above, would tell us as forecasters that these cells should continue to maintain themselves (at least) for the next several radar volume scans. Very cool! JJW

12Z LAPS verse RAOB Analysis - KMFL

The area over KMFL was the only area in south Florida that was partially clear. The 12Z Sounding matched well with the 12Z LAPS data showing some drying in the lower levels (between 900-700mb) with a PW value of only 0.5". Then as you go up further into the atmosphere into the mid and upper levels (700-300mb), the LAPS PW value is only 0.3". But the total PW value at KMFL within the LAPS data is 1.36" compared to the sounding value of 1.5". Also of note...the satellite winds at each of these layers matched up well the the winds in the 12Z sounding.

Further more...the area where some convection fired earlier this morning was near Miami in the area where there was 800-900 J/kg CAPE and -4 to -5 LI's.

~Lilly Miller~

Probability of CG Lightning Verification (Small Lead Time).

Note: The CG Lightning Probability product is not a GOES-R or JPSS funded project.

The image below shows MRMS Isothermal Reflectivity at the 0C and -20C levels, as well as the probability of CG lightning (colored blobs) at 1810 UTC. The mustard colored blob with the cursor readout showed a 60% probability of CG lightning at 1810 UTC.

The image below shows the same as above, with the addition of CG lightning observations at 1812 UTC. There was a positive lightning strike detected with this storm at 1812 UTC, near the cursor readout. This provided a small lead time for the detection of CG lightning with this cell. JJW

Environment / Beginning of Shift

As the week goes along, it's harder to find severe weather across the country.

Jennifer and I have been assigned the MFL CWA this afternoon. At first glance at the LAP products and radar, there will be continuing thunderstorms this afternoon, but most likely all but a few storms will just be ordinary fanfare today.

Despite the very thick cloud cover (tan color upper right), the satellite seems to be doing a fairly decent job with the products today, including CAPE, LI, and Layer PW. GFS is filling in the vast majority of our CWA though.

-BW

CI Underestimate with cell in Weakly County TN.

The CI product in the upper left image below showed only about a 34% chance of CI at 1730 UTC for the cell that did develop later on in Weakly County, TN.

The image below shows that cell at 38 dBZ over southern Weakly County, TN at 1745 UTC. Thus, this cell developed despite the relatively low 34% CI value at 1730 UTC. This initiated along the pre-frontal trough and moisture plume axis. JJW

To convect or not...

Layer GOES LAP PW still suggests convection plausible through mid afternoon ahead of surface cold front associated with anomalous/cold upper low dropping south out of the Great Lakes and into the TN valley.  However boundary layer moisture as analyzed in H9 layer PW primary limiting factor in potential coverage of storms with at best isolated activity indicated.  Will continue to monitor...

Tornadotod

LAP Total PW and Good Sampling with Clear Skies.

The 4 panel image below shows the cursor readout over the middle of the Memphis CWA. The LAP total precipitable water image in the lower right shows a plume of modest moisture entering the CWA, moving southeastward with a pre-frontal trough. This is associated with showers developing, with the CI product (not shown) showing some lower end probabilities. This image also shows no CAPE in the upper right image, with positive LI values (stable airmass) in the lower right image. The upper right image shows good sampling of the airmass ahead of the pre-frontal trough, with mainly clear skies. These images suggest that a stable airmass remains over the area, despite the modest moisture plume moving into the area with the pre-frontal trough. It may be tough to get convection to initiate given how stable it is at the moment. JJW