AllSky & TPW Check

Posted in Live Blogs, News on by Michael Bowlan.

Did a quick check of the merged TPW and AllSky products and as previously advertised/anticipated, the convection has been riding right along the gradient of the higher instability, but there is some discrepancy as to whether it’s right in the heart of the higher PWATs or along the leading edge, depending on if you’re looking at the AllSky or TPW, respectively. Noticed quite a bit of a latency in the availability of these products (up to an hour), which wouldn’t be good in an operational setting. Compared the values of the TPW and AllSky PWAT with the RAP, and the AllSky matched up much closer to the RAP. However, with the amount of cloud cover in the region (for obvious reasons), the GFS is the predominant data type (basically a model-to-model comparison). Either way, the general idea/trend is helpful if serving as a mesoanalyst in an operational environment.

~Gritty

(CAPE)

(AllSky PWATs)

(Merged TPW)

Hypothetical DSS Decision Support Screen – TAE support of Panama City Music Festival

Posted in Live Blogs on by Kristin Calhoun.

This is an example how the DSS meteorologist could use RGB imagery, gridded lightning products, CG lightning, and range rings for event support.

In this case – we are a HYPOTHETICALLY supporting the Panama City Music Festival denoted by the 10nm range rings.  Process would be to monitor products to predict when lightning is likely to impact an highly vulnerable population.

Layered TPW Shows Arrival Of Moisture

Posted in News on by Kristin Calhoun.

We’ve been monitoring a boundary on both the KEOX and KEVX radar, likely associated with weak surface convergence per surface obs. The layered TPW product shows a tongue of moisture approaching the region. It looks like a line of towering cumulus developed over the Gulf of Mexico as this moisture interacted with the convergence line.Sandor Clegane

Large ProbSevere Blob

Posted in HWT, Live Blogs on by Michael Bowlan.

Here is one drawback of ProbSevere that has been briefly discussed. The areal extent of the identification is not based off of some of the features that feed into it, but rather the dBZ reflectivity representation. In this case, for a MCV and line of storms, the blob below is approximately 152 miles long using a center line to calculate the distance. ProbSevere kept this size of storm for two 2 minute calculations before breaking the storms apart into several different identifications.

-Alexander T.

Tracking Meteogram Tool With AzShear

Posted in News on by Michael Bowlan.

One of the discussion points that has come up about the Merged AzShear product is monitoring the trends of the AzShear as storms progress. One way to do this that is built into AWIPS is the Tracking Meteogram tool. The following are a  GIF and PNG for a MCV just off of the MOB CWA. The radar image is above. The GIF shows the tracking tool and AzShear and then the plot showing the trends. In this case you can see general increase in AzShear values. There are some limitations of the Tracking Meteogram took like only being able to track one feature at a time, there is a lot of things to edit and modify with the Meteogram (the position and size of the tracking area), and this would not be an easy tool to modify and update while trying to focus on other warnings.

-Alexander T.

NUCAPS – Unmodified vs Modified

Posted in Live Blogs on by Kristin Calhoun.

Compared the NUCAPS sounding today (4/25) over WFO TAE.  See the point evaluated below (labeled point A below):

This is the “unmodified sounding.”  Overall the thermodynamic profile looked realistic.  Looking in the PBL – noticed it was about 2C too warm and about 2C to dry.

This is the “modified sounding.”  As expected, no change to the mid level thermo profile.  The PBL did have the “correction” applied – not the “cliff” in the temp profile.  Overall, I was expecting a more sophisticated PBL nudging scheme.  In reality – it just appeared to force the T/TD from the nearest METAR, with maybe some minor smoothing.  This is something a forecaster could do in about 30 sec – so didnt gain much.

BETTER OPTION:  employ a more sophisticated nudging scheme to the nearest RAP/HRRR.  If you going to modify the sounding – might as well nudge it to a model analysis – which have a long history of being used in severe wx research.

THE 3 MARCH 2019 CASE FOR AZSHEAR – #6

Posted in AzShear on by Thea.

Here’s another example of where the single radar AzShear product may have provided me with some lead time/added confidence in my warning decision making process, with the 0-2km merged product confirming the vertical depth of this circulation (first two images, below).

Further to the south along the line, the kinks within the line are that much more evident/prominent with the single radar AzShear when used in conjunction with other more traditional radar products (last image, below).

~Gritty

TAE Mesoanalysis #1

Posted in Live Blogs, Mesoscale Discussions on by Kristin Calhoun.

Forcing and storms remain well to the west of our CWA, but the atmosphere is becoming primed for strong to severe storms later this afternoon. LAPS All Sky retrievals show that ML instability has been steadily building, reaching roughly 500 J/kg along the Gulf coast.An 8 hour loop shows how the instability has built and gives more confidence that instability will continue to build ahead of the storms to our west. We did feel that LAPS CAPE seemed a bit underdone given the intensity of the downstream of the convection, so we took a look at the latest NUCAPS retrievals. We examined the point in the extreme SE of our CWA.The boundary layer on the unadjusted sounding required some adjustment to match the nearest obs, but overall, seemed to capture the general profile well. I was initially skeptical about the warm nose just above 700mb, but a similar feature was evident on the 12z sounding from TAE. This feature may have an impact on storm intensity and potential hazards, and it would be particularly helpful to see how this feature changes over time. Sandor Clegane

THE 3 MARCH 2019 CASE FOR AZSHEAR – #5

Posted in AzShear, HWT on by Thea.

Now here is an example of where the single radar AzShear product would have provided me with some lead time with respect to grabbing my attention sooner in further interrogating a tightening circulation embedded within the heart of the QLCS. As for the merged products, I was unable to gain any insight with those products for what appears to be this relatively shallow circulation.

~Gritty