Here is another set of images showing some shower development (there is no lightning).

2130Z CI product

2137Z Radar- not much to see, maybe “a” shower.

2145Z CI product- the highest probabilities have moved east

2147Z Radar.

2200 CI has increased in some areas. The yellow is over 60% while the green is 50%

2156Z radar is showing some shower developing

2215Z CI…still showing moderately high probabilities

2216 radar shows more showers

What is interesting about this example is that even when showers started showing up, even some that are near or above 35dbz, the CI is still picking up CI’s on it. This is likely because the CI product actually stops at a certain glaciation rate which is roughly equal to 35 dbz. So CI doesn’t “know” about the radar and the dbz levels. It just shows that even though CI may still be showing probabilities, there could still be something on radar.

Lauren13

Tested NUCAPS sounding for southeast Idaho.  The point used is circled.  The visible image was close to the sample time, but there may have been some cloud contamination.  Adjusted the surface observations upward based on the nearest MesoWest surface observation.  It was difficult because a lot of the lower points needed to be adjusted to keep it realistic.  The instability seems a little high, but it could be localized.  Will see how the thunderstorms in the area develop over the next few hours.

Update: This thunderstorm moved over the sampled area about two hours later.  It peaked at about 55-60 dBZ Composite Refl and had a NOAA/CIMSS Prob Severe Model reading of 24% at that time.  The 5-minute ENTLN Lightning 3 km grid peaked at 11 with this storm.  There was no ground truth to verify what happened there.  But will note the complex mountain terrain in that area and how difficult thunderstorm modeling and forecasting is in Western Region (with local effects, etc.).  This was a decent test.

-Champion

Updated at 430pm.

So the first thing we thought when we started to write this was the CI was having an issue “tracking” the cells because I couldn’t tell which cell actually developed out of all the cells the CI was indicating. This is part of the problem because some cells can get above 35dbz pretty quickly and between 15 min satellite scans.

Here at 1930Z, look at the area of light blue CI on the VA/NC border.

Next, at 1945z… it is hard to see because I didn’t circle anything but the dark blue is actually farther north, different cells, than where the previous light blue was indicating.

Next, at 20z, all CI probs are gone, indicating the storm likely got to 35dbz or didn’t form. And actually at 20z, a single lightning flash came up on ENI data.

Now, at 2015z, there is much more intercloud lightning flashes.

Lastly, at 2030z, the ProbSvr is at 13% and there are more lightning flashes with this storm.

The takeaway? First, it was quite confusing trying to go back and “track” which cloud the CI was tracking. Second, once I figured it out, the CI was less than 20% and for only 30 minutes until the storm developed. There is CI over 50-60% all over the Mid Atlantic right now and none of them are initiating. I found it quite interesting how quickly this one formed and it probably formed between the 15 min satellite scans making it hard to track.

Update::

I continued to follow this storm.

At 2040Z, the ProbSvr increased.

At 2050z, it increased again.

At 2052z, ProbSvr increased significantly. NWS issued a warning at 2054 (not that I am supposed to know that).

I didn’t have Raleigh’s or Wakefield’s radar up on my awips but I did get it at 2108 and there is already a hail spike.

At 2112z, the NWS received its first 1 inch hail report!

Lauren13

While doing a test of the GOES (West) CI Probability in southeast Idaho it showed probabilities anywhere from 60-70% (yellow shading in the right image).

The very next update the probabilities dropped to near zero (no yellow in the right image).  However, the corresponding radar showed no storms with dBZ greater than about 25 nearby.  It seems like ground clutter (a few pixels of 55-60 dBZ nearby) caused the CI Probability to improperly drop to near zero.

-Champion

A request from a happy clicker- we need an undo button on the soundings! That go for any sounding edit on AWIPS2 but I thought I would put it under the NUCAPS as well. In case you are wondering, the inversion at 875mb is NOT real. ha! That was my happy clicking and the only way to go back is to try and move the line back to where it was before! Point is, can we have an “undo” option for the last point I moved?? Without completely resetting the whole sounding and all my edits!

Lauren13

Something I have been thinking about Monday and into Tuesday was how I can use these products for Decision Support Services (DSS). Warning! This may be long!!

In NYC, DSS was constant-whether it be onsite at emergency management centers, concerts, 4th of July fireworks or NYE, we always did it. Now, in Huntsville, the DSS may not involve as many “people” but the difference is that almost all of the activities are outdoors (think: bass fishing, dragon boat racing- not joking) AND we can get thunderstorms/tornadoes literally every month of the year. When you are dealing with large outdoor events, a severe thunderstorm or tornado is obviously important and especially one moving towards the event. But in reality, ANY lightning is considered hazardous. When you are dealing with a 20% chance of less or a boundary that may/may not form, it is critical to find a tool that can give you any sort of lead time before the radar shows reflectivity.

So I’ll give you a couple examples of how the GOES-R/ProbSvr have helped or when it could have helped a DSS event.

Back in 2011 (or 2012 I can’t remember) I was working the Black Eyed Peas concert in Central Park with a forecaster (they broke up after that-I promise it wasn’t my forecast). The concert was later and we had some scattered showers during the day but a low chance at night during the concert. But it was middle of the summer and there was a sea breeze so all bets are off at that point. At night, we had no visible satellite and IR probably wasn’t going to get deep enough to tell us much. Long story short, we may not have known anything was happening…until it already was. Sure enough, around 9pm lightning started firing in cloud to the east and within 10 minutes, a line of thunderstorms formed no less than 10 miles to the east of the concert with light rain developing and moving over the concert. So what can help? I definitely think the CI product would have given us a heads up to start. The satellite imagery products of CAPE..etc.. may have showed us where something was increasing. Also, having the total lightning product showing us as soon as the in cloud lightning started or where the density was increasing would have also given us some lead time!

Early this year, Huntsville had a huge arts festival that draws over 100,00 people in a three day period. It is usually around the time of April 26-29 each year which, is peak severe thunderstorm/tornado weekend for Huntsville. We provide onsite DSS to them each day.  On the Saturday this year, the atmosphere was prime for severe thunderstorms. All that was missing was a trigger! But we knew if the cap broke and any boundary snuck down, a thunderstorm could pop up fast…and anywhere. I definitely utilized the Convective Initiation product and seeing those probs stay around 20% kept my faith we would be ok for awhile. I could have also used the satellite based stability products because we didn’t have LAPS data on the computer we had. It would have been the best thing other than the SPC meso analysis to tell us the current conditions.

In the future, these products have significant abilities to help with DSS across the country. I obviously like Convective Initiation the most but I can see the ProbSvr model helping us predict if a storm will collapse. One issue is if a storm is coming for a concert- do you hope it dissipates and risk lives or evacuate thousands of people and the cell collapses? ProbSvr could help us see a trend and that probability as it weakens/strengthens. The same goes for total lightning- the timeseries and tracks can show us if the lightning is lessening or increasing so make a better choice for evacuations.

Lauren13

Nothing going on still in the mid Atlantic! Currently monitoring the cumulus field that has been developing over much of the area, much of it along the front through the western LWX CWA. I like this display because these are the days as a forecaster where you just “wait” to see if anything can happen- if something does develop, it could be strong but will it? Sometimes it is tedious looking at all the Cu and wondering which will develop. Having this display up helps me quickly see what CU is developing more than others. I also have ProbSvr overlaid but since nothing is showing up on reflectivity yet, this won’t help.

Lauren13

After a brief look at guidance for convection chances in LWX today, it isn’t looking too great. There are some surface features with the latest analysis showing a trough stretching from central NJ down to central VA. A cold front is stretching through the entire country from north of Vermont to southern Mississippi. 17z GOES-R products shows the CAPE to the south in AKQ’s CWA as well as the highest LI/K index and PW values. Looking at the latest satellite imagery shows skies clearing after 16z over the CWA and cumulus fields developing. It looks like the latest satellite CAPE “may” be creeping west with the clearing and some storms showing some CI potential but nothing higher than 50-60% so far. RAP guidance doesn’t have the cold front moving through the region until after 21-22z. It also shows convective indices decreasing after that.

Summary? If we get any storms it will likely be before 22-23z moving west to east along the front. I don’t think the instability/shear is strong enough to get any significant initiation along the pre-frontal trough. I have highest confidence that areas to the south will get convection with the trough and/or the cold front.

Used satellite LAP algorithm to track the change in the environment over the course of the afternoon. Best instability was in the southeast CWA. Overlayed one hour total lightning with the CAPES and LI to see how the coverage of storms lined up with the best instability. Image shows this overlay at 21z.

Ongoing MCS from this morning accounted for the lightning east and south of the forecast area. Narrow strip of lightning west of the better instability was where outflow boundary intersected cold front/dry line. This area had better low level lapse rates and more time to recover after the morning MCS.

The mesoanalysis from SPC showed much higher CAPS at 21 and 22z than the values from the LAP algorithm. SPC was 1000-1500 J/KG while satellite derived was less than 500 J/KG.

Lynford