Daily Summary: Week 4, Day 2 (June 2, 2015)

Today’s activities took us just a little further east into the Bismarck, Billings, and Cheyenne CWA’s. The Cheyenne group would later move to the Aberdeen CWA as activity shifted out of the CWA. Participants were able to analyze the LAP products and later the NUCAPS soundings to get an idea of where severe convection was most likely. The CI product was also monitored for initial development during this period. As convection grew and matured, participants utilized the ProbSevere Model and Lightning Jump to identify significant changes in the storm that would warrant the issuance of a warning. The ENI total lightning products were utilized throughout the life cycle to monitor the evolution of the mature cells. The 1-min satellite imagery was helpful when monitoring for initial convective development, and seeing that development as it occurred, along with failed convective attempts. Additionally, the 1-min imagery along with 10-min winds generated from the imagery aided a forecaster in his assessment of the near-storm environment.

– Bill Line, SPC/HWT Satellite Liaison and Week 4 EWP Coordinator

Forecaster comments from daily debrief:

GOES-R LAP
- In Bismarck, GFS must have been well yesterday, area that went on to be long-lived, showers and weak tstorms, was moving into higher cape area, as it moved in, it did intensify. Southern part of line moved into strongest instability and straightened. Northern part moved into weaker instability, weakened.
- It would be nice to generate this with other models.

NUCAPS
- Billings surface conditions were pretty similar to local metar. Compared to rap for same timeframe, not a huge difference in moisture, RAP a little more moist. Took this in a nice clear spot. As far as being able to asses convective potential, don’t know if it provided me with additional info over rap

GOES-R CI

- A lot of continuous low probs everywhere, not terribly helpful in that case, sometimes it would hit somewhere random, so I'd keep an eye on it.

- Kept hitting on the boundary where the strong storm kept moving

- In Cheyenne, using east, algorithm picked outflow boundaries great, and did a good job

- Bismarck, great example of there was nothing, then it jumped to 60% out of no where, then next scan convective development. Otherwise, most were lower. Tried to pay attention to others. Low stuff distracting

- 30 and below noise.

- Values of ci never super high, highest was maybe 50%, focusing on those values then

ProbSevere

- I liked probsevere readout, being able to see the fields, especially cape and shear, much better than SCAN, which is difficult to use

- It seemed to work better with discrete cells

- We had a cool case in Bismarck, cell with probsevere increasing, cell split, two separate circles, picked up on how southern cell was much stronger, that went into my warning decision, probsevere showed that it was much stronger, and it did verify

- Cell not strong, didn’t look like it would be much, then probsevere jumped up, and I was surprised, but the storm did strengthen then. Lots of lead time.

- At my home office in Reno, radar starts at 8300 feet. Yesterday, I had a cell where the lowest tilt was at 12000 ft, probsevere was hitting high, did influence my warning decision, I used it to trigger a warning.

SRSOR

- What if you take 10 min winds, do a 1 hr image and fill in the whole domain. Someway to average them. We saw a jetlet come through, increases our shear. Something that could tell you the direction the jetlet is moving

- Cell in Aberdeen area moving south into our cwa (Aberdeen), you could see the cell redeveloping.

- You could see the new updraft form in the cell in a less favorable area, you knew it was going to die.

- W collaboration, Aberdeen call Bismarck, they could say that it looks like the cell is going to die based on trends in the 1-min.

- In Bismarck, hada good case where there was a clear outflow boundary you could see in the 1min, nice to see it progressing. Could also see the OTs really well. OT detection algorithm is nice because it is capturing the strongest OTs, weaker OT earlier, but then when the algorithm picked it up, it definitely looked beefier in imagery too. Nice to be able to quantify the OTs, something you cant do without an algorithm

- Depended on time of day to see good shadowing. It helped us in a good case in billings, new area well away from radar, vigorous updraft shadowing, told us that there was good updraft growth, and they did develop into strong activity, good indicator of new growth areas well away from radar

- Good for identifying boundaries, could see boundary propagating with storm moving along it.

- Enhance color curve to enhance 1-min

- Could see gravity waves in , thinking how that would help, big with research, looking at influence of gravity waves and tornadogenesis

- Mcs cruising, line of convection, where they meet, you often get convection

- It could help with drawing graphics, more accurate depiction of boundaries and their movement

Lightning jump

- I decided to issue a tor on one. Lowest tilt was 13kft. I had LJs – 4,6,11 sigma, OT lasting 5-10 min, if I'm gonna get a tor, its gonna be very soon, so I might as well issue.

- The Aberdeen case, looking into Bismarck to the north, we saw cell coming down, dry air over us, cell formed ahead of it and blew apart

- Looking for transition to supercell, we saw a jump

PGLM

- Prefer pixel look, gives more precise way to look at it.

- I am fine looking at this type of information for GLM.