Brewster Co TX storm not so Punky but modified NUCAPS was

The modified NUCAPS sounding over Brewster Co TX was more representative of the actual conditions at 20Z versus the regular NUCAPS. A dryline was positioned very near the point of interest and convective initiation eventually occurred  near the boundary in ~1000 ML CAPE air around 22Z.



Modified NUCAPS sounding w/ surface Td near 47F. MLCAPE ~ 1000 J/kg.



Regular NUCAPS sounding w/ surface Td near 54F. ML CAPE ~2000 J/kg.



RTMA Td analysis. Point H is where the NUCAPS sounding was taken from.



GOES-16 RGB at 2150Z showing CI occurring near the dryline.

Best option available?

Below is an example of a case where prob severe my offer the best option for a warning decision. This storm is outside of the best RADAR coverage available; however, strong development has been seen on Satellite imagery for an extended period of time. In a case like this, the PROB Severe Algorithm may be the best option for a warning decision, based on the data available.

South Beach

GLM Min Flash Area...Best Practice

Figure A


Figure B

Best Practice:  Look at lower left image on both Figure A and B (GLM Minimum Flash Area), notice Figure B has interpolate turned on which makes the product less useful since outer edges also have minimum values.  The GLM Minimum Flash Area of interest jumped out much better on Figure A without interpolate turned on.

Week 2 of the 2019 EWP Underway

6 National Weather Service forecasters are in Norman, Oklahoma at the Hazardous Weather Testbed for the 2019 Experimental Warning Program--Satellite and Radar Convective Applications Experiment.  Monday is being used as a training and AWIPS-II product familiarity/procedure building day.  This will serve all participants well in the coming week as much more active convective weather is expected starting Tuesday.  Many satellite and radar products will be evaluated, including NOAA/CIMSS ProbSevere v2.  ProbSevere v2 explicitly produces probability of severe hail, severe wind, and tornado.  One element of focus for the 2019 evaluation is the inclusion of a 'double contour'--one ProbSevere contour that is the maximum of ProbHail and ProbWind for a storm and an outer contour that is the ProbTor probability for a storm.  The double contour approach was a widely requested enhancement by participants of the 2018 HWT EWP as a mechanism for forecasters to monitor severe wind/hail as well as tornado threat on a single display (often all tilts radar).

J. Sieglaff

DSS DECISION SUPPORT SCREEN – TAE SUPPORT OF PANAMA CITY MUSIC FESTIVAL

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 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

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

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.

NUCAPS – UNMODIFIED VS MODIFIED

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.

TAE Mesoanalysis #1

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

Long Flash via GLM in the Anvil / Stratiform Region

GLM does a good job at capturing large flashes that appear in the stratiform region behind lines of storms. In this case looking at the Total Optical Energy for 5 minutes with 1 minute updates you can see the large flash show up (the yellows and the whites). Reflectivity from KMOB and Visible satellite are layers under the TOE data.



This large flash has Minimum Flash Area values between 1100-1700 km^2 with the Average Flash Area anywhere between 2700-3600 km^2. This is a large flash that extends back into the stratiform region (the Anvil) of the cumulonimbus clouds. You can see the lighter precipitation on the RALA (Reflectivity at Lowest Altitude) product below. The darker blocky outlined area is the Average Flash Size with other variables in the 4 panel.



One important operator note is to be careful what you time match with the GLM lightning data. In this case another forecaster had time matched with the 1 minute meso-sector of satellite and because of errors in that data the large anvil flash was skipped in the one minute GLM data. If the GLM data is the focus of your analysis always remember to time match with it and then use other data (like satellite or radar) on those time scales.



-Alexander T.