Transcript Follow-up work related to the OWLeS lake effect snow project - Ashante McLeod-Perez and Stephen Piechowski - SUNY Oswego.

OWLeS Research
Ashanté McLeod-Perez, Stephen Piechowski, Scott Steiger,
Lauren Cutler, Shania Nichols, Tyler Kranz, Andrew
Janiszeski
SUNY Oswego
Objectives
• Show Dual Doppler Analysis
• Show Objective Analysis
• Discuss lightning and findings
• Discuss WRF modeling
Dual-Doppler: DOWs 6 & 8
• Step 1: Edit via SOLO-3
• 2: Objective Analysis (2-pass Barnes)
• Grid spacing 300 - 340 m (so can resolve features > 1.7 km)
• Smoothing parameter 0.71 - 1.16 km2
• 3: Dual-Doppler
• Code provided by CSWR; thank you, Paul Robinson & Karen Kosiba for all of
your help!
• Upward integration of anelastic mass continuity equation to get w
22:50 UTC 2013-12-18 Dual Doppler Plot
06:57 UTC 2014-01-07 Dual Doppler Plot
Sensitivity tests and future work
• The beam width of the DOW is
0.93
• DOW oversamples so we can
adjust the beam width
• Reran objective analysis for
06:57 UTC 2014-01-07 using a
0.7 and a 0.5 beam width
• The images were clearer but the
data did not go up as high as
with the 0.93 beam width
• Mask the edges of the Dual
Doppler plots so large vorticity
anomalies don’t appear
• Finish 07:00:10 UTC-07:02:30
UTC 2014-01-07
• Create a loop using 06:57 UTC
2014-01-07 and 07:00:10 UTC07:02:30 UTC 2014-01-07
Objective analysis for 06:57 UTC 2014-01-07
using a 0.93 beam width vs 0.7 beam width
Lake-Effect Lightning
https://www.youtube.com/watch?v=KXRe7npyw4Q
http://wivb.com/2014/11/14/more-lightning-in-our-future/
Some quick facts for NLDN Flashes
• After grouping together the NLDN data into flashes, we found that 22:50 UTC 201312-18
• featured a total of 3 CG flashes and no IC flashes. All 3 of the CG flashes occurred
within 300 m of a wind turbine. The first flash was classified as an LTUL, while the last
two flashes were SIUL’s.
• 06:57 UTC 2014-01-07 featured a total of 7 IC flashes and 15 CG flashes (22 flashes
total). In other words, about 32% of all the flashes were IC flashes and about 68%
were CG flashes.
• Out of all the 7 IC flashes during 06:57 UTC 2014-01-07, 4 of them occurred within
300 m of a turbine. Since there are no CG strokes involved in the IC flashes, we could
not classify these as SIUL’s or LTUL’s. We simply classified them as regular IC flashes .
• Out of all the 15 CG flashes during 06:57 UTC 2014-01-07, 5 were categorized as
SIUL’s. 2 were categorized as LTUL’s. The remaining 8 were categorized as regular CG
flashes.
• For 06:57 UTC 2014-01-07, exactly 50% of all the CG and IC flashes that occurred
were within 300 m of a turbine or TV tower. For 22:50 UTC 2013-12-18, 100% of the
flashes occurred within 300 m of a turbine.
22:50 UTC 2013-12-18
Green: Cloud to
Ground lightning
Red: Intra-Cloud
lightning
06:57 UTC 2014-01-07
Lightning Hypothesis Figure
WRF Modeling Objectives and Overview
Test different PBL schemes to determine performance in resimulated lake-effect events. Use of PBL schemes with TKE
profile for determining PBL height was chosen.
Previously only used YSU scheme, which uses BulkRichardson number for PBL height.
Using wrf output every 5 minutes from 22:50 UTC 2013-1218, create plots of PBL height, snow mixing ratio and
precipitable water ( both observation periods)
Cross-Sect at 00z 28 Jan WRF-RAP int MYJ
RAP-int. MYJ Cross Sect. 00Z 28 Jan.
PBL height increasing?
Certainly looks like it as
we travel through the
band.
Utah Obs. Sndg at 03z 28 Jan vs MYJ (left) and YSU (right)
Here, observed sounding
has deeper boundary
layer (~ 50 mb).
PBL Height (m) overlaid with Snow Mixing Ratio (kg/kg) for
07:30 UTC on 2014-01-07
Conclusion
• 06:57 UTC 2014-01-07 showed better miso vorticies during lightning
than 22:50 UTC 2013-12-18 which did not have miso voticies but had
lightning. This shows that our hypothesis of miso vorticies and
lightning being related need more investigation
• Cloud to ground lightning strikes were found to occur inland as
opposed to along the shoreline. Most CG lightning was collocated
with wind turbines.
• Maple ridge windfarm may be a factor in lightning.
• Initiating the SUNY Oswego WRF with the RAP produced the best
results, but still the output PBL heights were shallower than observed
heights.