DLH - Nifty Convection Monitoring Procedure

2150Z: I decided to try looking at smoothed GLM data overlaid on visible satellite by using the "interpolate image" & "interpolate colors" options along with some transparency in AWIPS. On the same image I also overlaid ProbSevere polygons & GOES CI probabilities. It was much easier for me to interpret GLM trends while having some of the texture from the visible satellite imagery. The identification of new updraft growth in the GLM flash extent density data was much more evident with this procedure vs just using the GLM data alone. ProbSevere polygons were useful in monitoring the intensity trends of the storm at a glance. Finally having the GOES CI probability helped in a zoomed-out view to identify potential area of new convection. I'm impressed at the amount of data I'm able to view in this procedure without the whole thing looking too cluttered.

Loop of above procedure showing storm evolution in SW MN:

Peter Sunday

DLH - Mesoscale Discussion

2100Z: Storms have been ongoing for a while across the region but waited to write this post until the modified NUCAPS soundings were in. Right off the bat the all-sky CAPE does not seem to capture the general spatial pattern well compared to SPC mesonalysis/HRRR & observations. The all-sky suggests CAPE over 1000 J/kg over NW MN & SE MN & along a narrow tongue from southern MN up towards the Twin Cities. However mesoanalysis shows CAPE minima in these areas along with high CIN. Furthermore the all-sky LAP CAPE does not seem to capture the extent of the stable capped region in NE MN where storms have struggled in so far today.
2030Z LAP all-sky CAPE:

2000Z MLCAPE Mesoanlysis:

Furthermore visible satellite shows little cu development in the regions of suggested highest instability in NW & SE MN, with minimal GOES CI probabilities as well. 
2030 Visible Satellite/CI probablities:

Gridded NUCAPS 500-700 mb lapse rates match up quite well with mesoanalysis with rather marginal values of 6-6.5 C/km across most of MN. However, NUCAPS does not appear to pick up on the EML moving up from SD up into SW MN where mesoanalysis as well as the HRRR/GFS/NAM all suggest values greater than 7 C/km.
NUCAPS/HRRR/GFS/NAM 500-700 mb lapse rates:

 Overall, the thermodynamic environment does not have me too concerned about widespread severe weather today. Effective bulk shear values of 30-40 kts suggests some organization is possible & it will be interesting to see if the current cells eventually merge into a line as the HRRR suggests, and create more of a damaging wind threat. Some cells have spiked up at times this afternoon with ProbHail & ProbWind values over 80% but otherwise have not been able to maintain this intensity.

Peter Sunday

MAF - Mesoscale Discussion

1930Z: Moderate instability was present across SE NM & W TX associated with mid to upper-50s dewpoints out ahead of a dryline. All-sky CAPE shows an area of 1000-1500 J/kg across SE NM & into the trans-Pecos region of TX with lower values generally around 500 J/kg or less across the TX Panhandle/Permian Basin & over the Davis Mountains. These CAPE values match up well spatially to SPC mesoanalysis but mesoanlaysis shows CAPE values on the order of 500-1000 J/kg higher compared to the all-sky. CAPE values are forecast to increase to around 2000-2500 J/kg through the afternoon so will be interesting to see how the all-sky & NUCAPS products handle this evolution into the afternoon.
All-Sky CAPE:

Identifying the exact location of the dryline is tough due to the limited surface observations between MAF & EPZ but using the Simple Water Vapor RGB I was easily able to identify the dryline extent of the dryline with the dry air/green colors to the west & moist air/turquoise colors to the east. Also neat was the presence of dry air wrapping into a circulation over Mexico & kicking off convection to its east.
Simple WV RGB:

Shear is next to nothing today & will be the limiting factor in terms of severe weather out of any storms that develop today with effective bulk shear forecast to be lees than 30 kts. NUCAPS soundings are not in yet so can't compare mid-level lapse rates to mesoanlaysis but they look to be on the order of 7 C/km. DCAPE over 1000 j/kg suggests a downburst threat so I am primairily focused on the severe wind threat with any storms today & the potential for ow-end severe hail in the strongest updrafts.

A cell is already ongoing over the mountains of southern NM CI but otherwsie the CI product is quiet across the area. The glitchiness between frames is evident again but an increasing trend from 20% up to 50% is evident over the Davis Mountains of SW TX. For now I am focusing on the storms in NM & this area of TX for further convective development.
1930Z CI:

Peter Sunday

Observing Pre Convection...Midland, TX

Getting up to speed on the environment before the storms fire up.  Cape should increase in the late afternoon.  Low level lapse rate around 8.5...mid-level at 7.5.  I used most observations from the SPC site (my routine).

Using the new tools in the HWT I immediately loaded the local radar with the ProbSevere Model option.  As well as a 4 panel for lightning. Popped up the METARs, visible SAT & CI over it.

As I'm setting up my desktop I noticed a radar echo showing up west of Hondo, NM. Compared the CI overlapping with the vis Sat & it makes sense that there is a gap between CI data, the convection has already started there.  The higher colors on the CI show more areas where I'm watching for more storms to pop.

-

-Penny Gardens

ABQ - 2300Z Update

2240Z: Heading into 23Z, ProbSevere indicated a likely severe storm SE of ABQ with ProbWind 88%, ProbHail 76%, & even ProbTor of 21%. MESH values are slightly higher than 1", & the prescence of a mid-level mesocyclone along with -20C reflectivity greater than 50 dBZ all indicating the potential for severe hail.
Interestingly enough, there continues to be little correlation between increasing trends in the GLM fields & increasing storm severity (gif below). This has been noted in past HWTs with western storms which may be a limitation with using GLM products in this region.

Zooming out, GOES-16 IR/VIS data shows some cu development & cooling cloud tops across southern NM.

Looking at the CI fields, not too much is expected with this development with values generally 50% or lower & severe CI probs only around 10%

And finally, little to no increasing trend in GLM Flash Density makes me even more confident in anticipating little to no development of this convection over southern NM

Peter Sunday

ABQ - First look at CI Probs

2145Z: Latest HRRR has backed off on convection this evening over southern NM, with the ongoing clusters north of ABQ likely remaining the main event. However, the last couple HRRR runs have suggested a lone supercell tries to develop across southern NM so decided to analyze the CI probability & Severe CI probability across this area.

The first issue was deciding which GOES satellite to use, east or west. Obviously I would prefer to use the higher spatial & temporal resolution with GOES 16, but the ABQ WFO is getting near the edge of the GOES 16 disk. Data is available in AWIPS for the astern half of the CWA (east of I-40) but I don't know how much I can trust the data this far from the nadir.

Looping through about an hour of data I see a lot of sporadic jumps in probabilities for both the CI & Severe CI products. On the Severe CI product gif below, values are generally low around 10% but the product will often jump up to 50% or even 100% & back to 10% from frame to frame. While the values overall remain low & no increasing trend is evident, the sporadic increases in data lead to lower confidence & trust in the data. Similar but less extreme jumps in values were evident in the baseline CI product. I did notice a slight trend in increasing CI probabilities but we're only talking from 10% to 30-40% so I'm no longer expecting much in the way of development across southern NM this afternoon. I really like viewing the CI data overlaid on GOES-16 Channel 2 visible imagery to better identify the cu clusters that may be the next to initiate.

I also looked at the CI & Severe CI probs from GOES West. It's tough going back to the coarse resolution & 15-minute imagery of GOES-15 when you've had a taste of the new & improved GOES-16. In our current GOES-16 world I guess I'm just too impatient to wait 15 minutes for data & it was hard to zero in on favored areas of cu development with the coarse resolution "blobs" . The values for CI & severe CI generally matched up well with the values from GOES-16 so that bodes well for the tuning of the GOES-16 product.

Week 2 summary and comment round up

As week 2 comes to a close 11 May 2018, we review the comments from our final debrief below. Much of this echos the discovery and opinions from throughout the week.


GLM:

• Training remains an important question and consideration.  Would love to have subject-matter expert available locally for all forecasters (may become frustrated by the data and not use it w/o that person).  
• SOO or focal point can be that local subject-matter expert, however, this will demand evolving training exercises.  Move beyond VLAB, work with WDTD to create hands-on and locally-relevant training opportunities.
• Typical order of use this week:  Total Energy (primary), FED (secondary) and Flash Size (tertiary). 
• Limit the amount of data available on first release (only to the three products listed above???); eliminate point-based or centroid products.
• Integrate GLM data with ground-based lightning systems to help understand and alleviate parallax concerns, particularly when issuing a special weather statement or IDSS for lightning.
•  Want to work more cases and focus areas.  E.g., where radar coverage is poor (western US), fire weather, and aviation -- appears that areal extent and pre-Cloud-to-Ground information will be important.  Context is important and will drive various need/demand for individual GLM products.

ProbSevere (all hazards):

• Did not trust the probabilities in all environments this week.
• Did well with hail and if storms were a bit more steady state.
• Seemed to behave worse in western US and with wind threats.
• Liked using the probabilities as trend information for storm intensity, but not necessarily a particular number.
• Would like to see trend graphs not only of probs, but also internal items in algorithm.
• Preferred the individual hazard products (read-out too long on single ProbSevere)
• Some confusion regarding time scale of probability (minutes vs hour)
• ProbTor could be more difficult to understand reasoning for probs than other hazards; Use a lower threshold for ProbTor and adjust color tables accordingly.
• Would like to see "weak" "strong" indicators on more than just glaciation rate. 
• Difficult to pick out differences in storms between 70-100% probs; color table could use more delineation at higher end (all storms appeared pink).
• Could be useful to communicate impact w/public - would remove numbers and use Low - Mod - High for threats.

Convective Initiation (CI) and Severe-CI:

• Not terribly impressed by algorithm:  completely missed some objects, overdone in some areas, underdone in others.  Hard to understand why.
• Can provide situational awareness, does give some indication of development, but algorithm may need modifications to be more useful.
• Suggest either removing probs <30% or moving to transparent (to know algorithm is tracking these storms).  Large blue confetti-areas are distracting.
• Difficult to utilize in environments where noisy and chaotic. 
• Did not understand differences between algorithms (CI and SVR-CI):  why would CI be low and SVR-CI be high? 

All-Sky LAPS:

• Used in pre-convective environment, showed instability and moisture fields and gradients in those well.
• Could use in social media posts to explain the "WHY" behind the forecast.

NUCAPS:

• Data from JPSS integration was new (or relatively new) to most forecasters.
• Development of best-practices, easier menu-access (not buried in volume browser) and quick-guides would be helpful for increased use.
• Earlier access to data is highly important, but also need better visualization options.
• NSHARP options need to be more user-friendly, cumbersome to pull up multiple soundings in different CAVE displays to compare.  Would like to access shear parameters and get box&whisker plots.
• Difficult to evaluate trade-off of no-data available vs model integration into products.  Would like keep separate from LAPS options, but can be difficult to evaluate with gaps in data coverage in gridded products.

CI and Severe CI in northern Nebraska

CI and Severe CI worked better today across northern NE highlighting areas of initiation and potential for severe.

- Jack Swigert

No To Low CI and Storm Initiation

Noticed that a cell (circled on image) over northeastern Wyoming did not have any severe CI, low CI (17%) before it initiated. Not sure what may be happening with the algorithm. There was no cirrus canopy around the cell other than other convective initiation (south) and clear air (north).  Included the beginning image:

Here is the last image I took of the storm:

You can see that it has a strong updraft (via IR Satellite). I do not have severe CI displayed but it had no values in around that particular cell. With it moving towards a gradient in instability, could see it strengthen further soon.

More to come...

Supercell

Severe CI Product hinting at initiation in northern Nebraska throughout the early afternoon

northern Nebraska convective initiation after severe CI hinted in that region with high percentages (although jumpy) all throughout the early afternoon.

Severe CI Probs but is it true

Looking at 1 min GOES Ch2, Ch13 Satellite data while overlaid with Severe CI showed several areas that have quite high severe CI probabilities initially but then trend downward with probabilities. This is apparent over the NW portion of the LBF forecast area (north Platte) close to the warm front. So, not sure of the effectiveness of the severe CI data. Included a screen shot here.  Also, noticing convection protruding from a perhaps a dry line across eastern Wyoming. Seeing that developing with the 1 minute imagery was quite valuable. Will try to upload an animation to show but proving to be problematic to create an animation of this particular data within AWIPS.

 

 Here's the animation...

More to come...

Supercell

CI Low but Severe CI High?

Today's CI products seemed to pinpoint the initial convection for the day the best so far this week across SE Wyoming. However, CI was highlighting convection potential at 30-40% but Severe CI was highlighting areas 80-90% off convective clouds off Snowy Range and Laramie Mountains. Why would it only be a low chance of convective initiation but a higher chance of severe convection?

Update #1: Severe Warnings were issued for these storms around 2030Z
Update #2: No severe reports across WY were in as of 0045Z

- Jack Swigert

More from CI Product

CI Product around 22:00 UTC

Severe CI problem with initiation near cirrus

Noticed that a storm moving from ARK to MKX was close to the cirrus canopy and there was no signal on the CI product.  It eventually developed into a sub-severe storm. Could go severe later, but just something I noticed in terms of the product not resolving close to the cirrus canopy.

Just to make clear which cell (there were several I was looking at) that didn't have any CI on it. Here's an annotated image. Just follow storm across Wisconsin as it strengthens.

One other suggestion: Having the values in blue from 10-30% is not very useful. Maybe 30% blue and then the colors above that??

More to come...

Supercell

CI Product Struggles

Monitoring the Convective Initiation (CI) Product this afternoon for development across Wisconsin, Illinois and Indiana. It seemed to highlight potential development best over Illinois but struggled over Wisconsin (especially Madison supercell) and Indiana. Struggles could be attributed to high stratus blockage and such. With the values jumping back and forth between low and higher CI percentages and the sheer amounts of blue highlighting (low CI probs) across the map, I find this product to not be of much use in a situation like today. It could be beneficial to completely block out lower CI probs (say 40% and below) as this could possibly direct a forecaster's attention to areas more likely for CI.

- Jack Swigert

IWX (more analysis) with CI and All Sky LAPS

Looking at all sky LAPS, there is a clear gradient of two separate areas of higher instability. Values vary between the models and the sky LAPS, but wanted to look at how the LAPS data looks compared to GFS (top right),  HRRR (top left), and Layer H20 PWAT from all sky LAPS.

One reason I am looking at the PWATs is to also gauge the southerly fetch/LLJ. I can see two split areas combining into one. It also looks like where the all sky LAPS is definitely highlighting the same maximum areas as the all sky LAPS which is to be expected given it is derived from GFS in cloudy areas.

Turning to the convective initiation product. Did see where the Severe CI is showing higher probabilities over the western portion of the ILX and LOT forecast areas. That is also coinciding with higher Total Power in GLM but not sure if they'll strengthen to severe.  They are entering that area where the instability increases over western portion of ILX and LOT forecast areas. Will keep watching to see if these storms realize the instability shown.

More to come...

Supercell

Usefulness of CI when overlaid over visible satellite

1-minute visible satellite (meso-sector) with GLM 5-min FED with 1-minute updates and CI product overlaid.  Could be useful in determining which cloud features (seen on visible) could be the first ones to be convective (since we probably know that storms will initiate off the CU field in western IL.

NUCAPS, RGB, & GLM Iowa Severe May 8 Week2 HWT

In Advance of the developing severe threat this was notices on NUCAPS comparison to Total Precipitable Water

RGB Cloud Convection Product with NUCAPS Improved Latency and Goes Total Precipitable Water shows close match with actual sounding. 1.09" in NUCAPS Sounding, While Total Precipitable Water is showing 1.21" Northern Nebraska NUCAPS point sounding showing .99 with Total Precipitable showing 1.10" ---Modified Nucaps shows only tenth of an inch added difference with this one from .99" to 1.00" and with the other sounding in Southern South Dakota it increased also to only 1.10 from 1.09 for Nucaps Sounding with precipitable water at 1.21"

Initially, I experienced difficulty loading the ALL Sky LAP CAPE product, but once loaded in a separate window the product arrived without issue.
Then, I compared NUCAPS Modified Points on the Skew-T with the ALL Sky CAPE image time matched to 18:58 Z. This indicates a slightly lower CAPE of values between 50-75 on the soundings than the ALL SKY CAPE image, but the data overall appears to correlate well in this time match.

        The Water Vapor Imagery 4 panel displays shows significant available moisture in mid-level and upper-level regions over the Dakotas and Iowa. Viewing the lower level Water Vapor at the GOES East Conus 7.34 low-level water vapor imagery IR band, the dryer surface level conditions are visibile along the Iowa/Missouri border. This is also an area where an outflow boundary exists and where at 22:49-22:52Z there is a rise in wind damage probability using the Severe Probability Index, but notably no indication of increased CI or any cloud identified with the CI probability product. See the two 4 panel images below.

Below is the GLM Total Energy product data overlaying CI with the Severe Prob product. The GLM seems to be a better indicator of the most active and developing potential for areas or storm clouds with potential for severe threat than the CI in this brief window. This is based on the 21:3Z views through 22:52Z during which time the storms did not reach severe status, but did show strong convection and more organized activity at 22:52Z than the CI product suggests expecially in the Western Iowa and Northern Nebraska region.

 The slide below shows the composite radar Image from 23:12Z with the best rain near the GLM Total Energy indicated storm areas from the 22:52Z image shown above.

MK

May 8 Evaluation of Test Products in AWIPS2

Area just north of main convection rapidly strengthened (lightning via glm, overshooting top in visible, high dBZ core in MRMS shown below)

Area just north of main convection rapidly strengthened (lightning via glm, overshooting top in visible, high dBZ core in MRMS shown below)

High dBZ core situated away from main convection, noted by large cloud flashes via ENTLN

CI product showing the scarcity of the likelihood of newly-formed storms in central IA in the near future

CI product showing the more unstable environment in SD, indictaed by several isolated storms showing high lightning rates and high dBZ cores

ProbSevere model showing increased probabilities (30-40%) of storms becoming severe in SD

ProbSevere doing a good job at helping locate storms of interest for further investigation in addition with spatial extent of GLM FED

GLM total energy looks to better identify storms with higher ProbSevere hail potential (top right panel, storms in SD).  However, GLM FED does not correlate to total energy, in fact, the storm in northwest IA exhibits a larger FED, but lower flash energy than the storms in SD.  In fact, the ProbSevere wind potential is the main threat for this storm.  I.e., differentiation between flash energy, flash rate, and hail/wind threats.

strange non-meteorological GLM feature appearing east of Florida/Bahamas

ProbSevere and ltg nicely capture the evolution of this storm in north-central SD to  its growth, most intense phase, and decay

Waiting for Convective Initiation in Iowa

Overnight storms continue across northern Iowa. This activity has left an outflow boundary to the south straddling northwestern counties of the CWA. Modest theta-e advection ahead of approaching vort lobe moving out of the Dakotas with temps climbing into the low to mid 80s and dewpoints in upper 40s to mid 50s. Expecting convection to fire up later this afternoon around max heating along the remnant outflow/frontal boundary in northern/western Iowa. Strong winds primary threat with steep lapse rates and DCAPE values 800-1000 J/kg. As of 1900Z, GOES Convective Initiation prob 0-2 hours only showing 10-20%. Tongue of instability nosing quickly into western Iowa as well as evident via AllSkyLAP Layer CAPE of 1000-1600 J/kg.

- Jack Swigert