ALY MD

A quick look at the environment shows a limited amount of instability based on LAP CAPE (up to 900 J/kg). LAP LI continues to drop (as low as -6) There is some clearing across our eastern counties which the CI product is expecting some development (50-60%). A line of storms is working into that area of clearing and wind velocities are starting to strengthen. Warnings will likely be issued soon.

-BT

Boston Outlook for this afternoon/evening

At 17 UTC 9 June 2015 GOES-R LAP Alg 400-500 J/kg CAPE seems in line with SPC.  GOES-R LAP PW  1.4″ of PW highest in the NW part of our CWA.  GOES-R LI showing -1 to -3 with TT values in the upper 40s. KI are rather high around 34 for southern New England.  SPC mesoanalysis shows 30 kt of 0-6km effective bulk shear.

SRSO vis showing development on eastern side of upper level trof through 1837 UTC and showed a hole in the clouds developing west of ALB and just behind the main convection.  Also shows cooling tops at the S edge of the line in ALYs area.

CI products showing some 40-60% with up to 79% in SW CT, so expecting cells to strengthen as the line moves in to ALY area then in to western part of BOX.

MrSnow/inthecards

Daily Summary: Week 5, Day 1 (June 8, 2015)

As with previous weeks, much of the time on Day 1 was spent familiarizing participants with the AWIPS-II system, blog, and products under evaluation.  The three forecast pairs operated in the State College, Nashville, and Sterling CWA's. Along with the GOES-R LAP, NUCAPS, GOES-R CI, ProbSevere, and Lightning Jump products, the Nashville and Sterling groups were able to view the PGLM total lightning products on this first day of activities. Additionally, the 1-min imagery from GOES-14 was once again available in AWIPS-II for the week.

Bill Line, SPC/HWT Satellite Liaison

GOES-R LAP
- PW values looked ok, CAPE was off compared to other sources

NUCAPS

GOES-R CI
- An area near Memphis had 60-70% probabilities, a storm did develop from this
- Cirrus cover was an issue

ProbSevere
- At first it was helpful coming in when storm were on-going, specifically in showing where we need to focus our attention. Later in  evening, storms were producing strong winds, and  we were issuing despite low probs
- Did not seem to interfere too much with seeing features in radar
- Near reflectivity gradient might be hard to see, but can click off the product easily if necessary
- Type of severe would be good to include

SRSOR and 1-min OTD
- It was helpful to identify and track the progress of gravity waves
- You could really see where a bay breeze front was set up
- Noticed storm in PA wasn’t moving all that much, had a stationary OT; this was really helpful to see
- I liked to hyperloop the 1-min imagery as it allowed me to see how things were evolving
- We are seeing what happens in the 15 min period that we are currently not able to see

Lightning jump
- It seemed like if your using 1min data, the colors change quickly, so you can miss significant jumps
- Mostly had it on its own panel
- I  viewed it with visible satellite imagery as its background/underlay

PGLM
- I liked the 6min summation as significant changes in lightning activity were less likely to be missed

Charley…Most Useful Products Today

Overall with the pattern in place it seemed the DVIL and ProbSevere helped me to make warning decisions more than other products.  I used base velocity for a few of the SPS/warning decisions.  DVIL and clusters of total lightning helped focus on the stronger storms.  However there were several storms that we issued on with lower lightning data.  In particular the cell over Williamson county did not have a lot of lightning with it, but it did produce several reports of hail…and we later learned it had some wind damage as well.

We had some hiccups with the SRS satellite data not coming in.

Lightning time series data were not as difficult to work with as I anticipated.  I would expect a problem though if I had more than one storm to focus on.  Perhaps with experience that will get easier.  It was straight-forward to understand when cells falsely jumped in lightning data, but because of cell mergers.

Stewart County Warning

Noticed more storms forming near the KY/TN border near the NW corner of Nashville CWA. The lightning jump alerted us early with a sigma of 6 that this was a storm that needed to be monitored with more interrogation below we decided to warn on this storm.

PNGA/lightning data on Warned storm Williamson Co

We were debating on whether or not to reissue a warning on storm and noticed that the PGNA product was showing an increase in total lightning and decided on issuing.

The time series product also showed an increase right before we re-warned…but quickly began to tail off again after we re-issued.

SRSO and Overshooting Top Stationary in PA=FFW

SRSO shows several things. First the overshooting top in PA was nearly stationary, anchored to the terrain by the southerly inflow impinging on the inflection point in the Appalachians. Dual Pol radar estimates up to 3.5″ rainfall there near Harrisburg, PA and a Flash Flood warning was issued for the area. A couple of the overshooting tops including this one were caught by the algorithm (denoted by the red grids in the visible imagery)  but one to the northeast was not as seen by visible imagery.  Also of note in the SRSO were the north south cloud streets in MD and the Chesapeake Bay breeze front just east of KBWI with cooler temps in the 70s and lack of clouds over the Bay into southeast PA. MrSnow/Wacha

CI Product

Just taking a quick glance across the SE portion of our CWA…

We noticed a few probabilities for CI early (50-60% max), but once the anvils from the storms to the west moved eastward, the model was not able to make any predictions.

-Shasta & Brick

Severe Probability along a line

One thing I noticed as the individual storm cells began to merge is the merging of the NOAA/CIMMS Probability of Severe product. While this does make some sense as the convective mode becomes linear… the problem I see is the sample gives characteristics for the entire line. Some of the sampled values make sense (Env. MUCAPE, Env. EBShear, etc…) but for something like the MESH value, I think it could be misleading. Instead, I would like the Severe Probability product to follow the stronger cells embedded in the line, thus breaking up the numbers some.

-Shasta

Thanks for the feedback, Shasta. We agree with what you are saying. We can make object-identification/tracking better to isolate cores in squall lines, but at the cost of longer latency. We are currently working on a way to have better storm discrimination at the mature stage without too much increased latency, however. So this should help with more spatially discrete fields like MESH. - JC

Severe Williamson County

Did not have a high lightning count

Had a quickly building DVIL

ProbSevere was high

Storm formed on boundary…moving right of mean flow had a 2-sigma lightning jump

Combination of above elements led to warning decision.

DVIL seemed to be the best tool to use here, as well as spectrum width showing the cell going up along a boundary.