MAF - Convective development associated with increasing all-sky CAPE

1945Z: Convection continues to develop over the Davis Mountains of SW TX. Some mid-level clouds/supercooled water droplets are being identified on the Simple Water vapor & Day Cloud Distinction RGBs as the cu over the mountains continues to develop. CI prob values continue to remain around 50%.

Simple WV RGB:

Associated with this developing CU was a large increase in CAPE according to the all-sky LAP CAPE product where values increased from 200-300 J/kg to 800-900 within the hour. I expect this trend in increasing instability to continue into the afternoon.

All-Sky CAPE:

Peter Sunday

AllSkyLAP Layer CAPE

The AllSkyLAP Layer CAPE product is also useful today, but comparisons with SPC ML CAPE values show that the AllSkyLAP Layer CAPE values are quite a bit lower than SPC's values. Likewise, a NUCAPS sounding from N VA shows ML CAPE values that are way lower that both SPC's and AllSkyLAP Layer CAPE values at the same time.

Going back to the AllSkyLAP Layer CAPE product, despite it's apparent "lower CAPE" bias, it is still useful, as storms across the Mid-Atlantic region today are beginning to fire along some CAPE gradients. One would expect that storms moving into a more favorable CAPE environment shown on this product would have a good potential to intensify. Seems like that is the case, especially across western VA and cntrl MD.

A challenge with AllSkyLAP products is that they are only available every 30 mins. It would be helpful to get these images every 5 minutes, to see environmental changes a bit quicker.

- Thomas Bell

Observations Of Products

ProbSevere-
The color table is hard to follow...probability for hail went from 71% to 61%.  It wasn't obvious that it went down just by glancing.  I looked at the color table at the top and rolled the mouse over it to see what happened.  

CI-
The colors jumped to yellow quickly, but would go away with the next scan.  Not sure what caused the spike.  A lot of noise and clutter with the lower values included. 

Mid-level clouds are picked up on the Water Vapor AGB.  We had to reference our "cheat sheet" to figure out that's what we were seeing.  It looked odd and jumped right off the imagery in the dry area.  Compared to the CI it had jumped to increased chance for convection to occur there.

*Side note on the Water Vapor...nice imagery! Easy to use to see where the dryline was located as there were barely any METAR stations around that area. The water vapor was obvious with the color table.  I could immediately tell where the dry air was located compared to the moisture.  The storms were trying to develop in the drier air mass...

 And just discovered the severe CI product.  This is a nice way to hone in on where ingredients come together for severe storm development.  The areas matches where there are mid-level clouds rapidly developing.  This area also  had a rapid increase in CAPE.




-Penny Gardens

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

GLM Event Density With Growing/Strengthening Updrafts (UPDATED AT 20:30 UTC)

[19:30 UTC] Convection is well underway here in the Sterling VA WFO. Have taken a look at the day-cloud convection RGB with strengthening storms in my southwest. With the mesosector positioned squarely over top of us, we are getting 1-minute imagery, which is spectacular in terms of monitoring the growth of a cumulus/mature cumulonimbus.

Also noted a fairly rapid uptick in GLM 2-minute Event Density with the growing/strengthening storms over this same time period, which would help focus attention on the developing convection in addition to the mature convection already in my northeast CWA. Also continue to monitor ProbSevere and will be sure to include any interesting findings as they become available.

Fig. 1: GLM event density every 2 minutes updated every 1 minute

Fig. 2: Day Cloud Convection 1 minute mesosector

 [Update at 20:30 UTC]

In watching the evolution of convection in the southwest part of my area, the increase in flash rate and event density was notable until about 19:35 UTC when the 2-minute event density and flash rate per minute began to decrease. The storms began to take on a bit of a bow shape, but there was no real increase in ProbWind leading up to approximately 19:35 UTC, when two damaging wind reports were received very close to each other and approximately 2 minutes apart. Interesting that ProbSevere, in this case, did not provide value as was expected.


Rosie Red

AllSkyLAP Layer PWAT benefits

AllSkyLAP Layer PWAT is helpful today when looking at storm development and surface obs across the Mid-Atlantic region. TS seem to have initiated along an old sfc front over NE NC, which coincides with an AllSkyLAP Layer PWAT gradient. Also, TS are firing along a sfc boundary as it interacts with the mtns over far N VA/cntrl MD, an area that coincides with an AllSkyLAP Layer PWAT maximum.

- Thomas Bell

Thoughts On ProbSevere

Looking at a developing t-storm almost outside the local radar, I thought about how accurate the ProbSevere would be compared to a typical radar sample.  The beam distance and height where it hits in the storm will affect the typical data sample.  But the ProbSevere could help to fill in the gaps with a more accurate probability to warn a storm.  Not that across Midland, TX there is a huge population area, but it just takes that one bad storm to make it on the "evening news" due to injuries or worse.  Another plus for the ProbSevere!

-Penny Gardens

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.

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-Penny Gardens

Day 2 Operations

Today we will be operating in similar locations and environments to yesterday in Midland, TX and Sterling, VA.

Michael

Week 4 Day 1 Wrap Up

We wrapped up yesterday's activities operating in Wilmington, OH and Albuquerque, NM. While there was wide spread convection, the severe potential was pretty marginal. Feedback is posted below:

ProbSevere

Provided very good confidence in the area with the storms moving through ABQ area

Seemed to be pretty well correlated with the radar characteristics

One storm the GLM lightning data provided more lead time than the ProbSevere did. The
ProbSevere took a few minutes to catch up with the features

Did good to provide awareness for which storms to track

Great tool to use with typical radar techniques

Good to use in comparison with other storms

Seemed to give more inflated values for a cluster of storms moving over Albuquerque

Use of a more segmented color curve might be more useful than the smooth gradient

Making it flash would be another idea

Liked having the full readout to see what all is going into the product

NUCAPS

Like having the color coding and point and click to pull it up from that location

CAPE values were actually quite a bit too high in ABQ yesterday due to really steep low level and
mid-level lapse rates that were a bit too steep

Being able to get multiple soundings from an area is very useful

All-Sky LAP

The CAPE gradients highlighted areas and was used as an observational check to the SPC
mesoanalysis. Nice to use in conjunction with other tools.

Values were a little low for the CAPE values as is usually the case

Having the all-sky with higher temporal resolution would be better. Having every 5 minutes would be
great.

Using a higher resolution model would probably be better or something to get a better gradient
between the non GFS and the clear or cloudy sky regions.

CI

It’s a little blocky or choppy looking, and taking out the lower end of the probabilities might take out
some of the noise and jumpiness of the data.

Did do pretty good in a null case of anticipating areas that were less likely for convection to form

Was able to compare the GOES West and Goes East in ABQ and having the increased time resolution
and spatial resolution from GOES East is much better

There were very many sporadic drastic jumps especially in the severe CI product where it would go
from 10 to 90 back to 10 which hurt the confidence in the product.

Would much rather see a steady increase or decrease instead of the sporadic jumps to increase the
confidence in the product.

Didn’t show any values for some of the more agitated cumulus areas

Cases where radar data is not available or less available it could be a beneficial product to continue to
work on and improve.

GLM

Used it a lot and was helpful for looking at lightning trends

Used Flash Extent Density the most

Not very strong correlation between lightning and severe weather in New Mexico.

There was not very much change in the FED in New Mexico as the storms were ramping up and
ramping down

FED and flash area seemed to do well to distinguish between some of the newer updrafts from some
of the older storms.

Mainly used the 5 minute with 1 minute update

The 1 minute data was a little noisy

The 2 minute data matches up well with the MRMS data and updates

Liked the color curve for the FED and was able to see some trends

The flash area curve seemed to be a little harder to see some of the trends