Figure 11: Schematic of (a) horizontal and (b) vertical MCS cross-sections for experiment Option IIIa. Vertical lines in (b) depict system-relative location at which spiral ascents/descents intersect the cross- section.

Option IIIa:

Goal: Document mesoscale wind fields, microphysical profiles, 2-D EFM coverage

Aircraft: The P-3 will conduct a series of 15 minute flight legs, at various altitudes, centered on the location of one of the mobile laboratories. The P-3 flies from A to B, then to point 1 at 8 kft and performs a spiral ascent to 23 kft. The P-3 then flies to A, then B, and then back to point 1 at 23 kft and performs a spiral descent to 8 kft. This pattern is repeated throughout EFM data collection. Tail Doppler radar data will be collected in FAST-continuous mode during the flight legs. Spiral ascents/descents will be conducted at approximately 1000 ft/min.

Mobile Labs: The mobile laboratories will line up perpendicular to the convective line to document the MCS's 2-D electrical structure. NSSL2 will launch a PTH sounding ahead of the convective line. NSSL1 and NSSL2 will then launch balloon-borne EFMs into the convective updraft and downdraft, respectively (launches separated by 5-10 minutes) followed by alternating NSSL1 and NSSL2 EFM launches approximately every 30 minutes.

Cimarron: During the balloon-borne EFM launches, Cimarron will collect data in PPI mode. Unlike in Region II, Cimarron data in Region I will be collected to high elevation angles in order to obtain quality upper-level wind data in the Cimarron-KTLX dual-Doppler lobes. Specific Cimarron scanning strategies are presented in Section 6.

Notes: The launch of other balloon-borne electrical instrumentation (Q-D, x-ray, field change, and cloud particle replicator) from NSSL1, NSSL2 and NSSL3 will be coordinated by mobile laboratory chief scientists. Cimarron may conduct occasional RHI scans when regions of aligned ice crystals are observed.