Various Features Influencing Convection Initiation on 12 June 2002 during IHOP_2002* Tammy M. Weckwerth (NCAR)

1
Various Features Influencing Convection
Initiation on 12 June 2002 during
IHOP_2002Tammy M. Weckwerth (NCAR)
Hanne V. Murphey (UCLA)Cyrille Flamant (CNRS)
Crystalyne R. Pettet (US NWS) Roger M. Wakimoto
(NCAR)Sophie Bastin (NCAR)
Work in Progress
WWRP Symposium on Nowcasting and Very Short Range
Forecasting, Toulouse, France, 5-9 September 2005
2
GOES 11
3
Composite Radar
4
12 June 2002
Are the intersections between the waves and
outflow preferred regions for CI?
Does the mesolow play a role in CI?
Are the rolls a factor in CI?
5
2050 UTC
6
Dropsonde Leg 2 CAPE CIN
Outflow boundary
NE
SW

• Incomplete soundings only up to 6 km AGL (445
  mb)
• No drops in CI air mass

7
ELDORA Observations of Waves

• Gravity waves in all fields ? 6-8 km
• Consistent with P-3, MIPS, GOES-11 and radar

• ELDORA fields _at_ 900 m AGL

8
ELDORA and Leandre II Wave Impacts
km

• ELDORA and Leandre II fields _at_ 400 m AGL

• Periodic signature in q, div and vort ?6-8 km

9
OK Mesonet 18 UTC Mesolow Impact

• LLJ feeding region of interest
• Dewpoints in the high 60s and low 70s

10
Freedom, OK MesonetMesolow Impact

• Local increase in southerly flow, perhaps due to
  mesolow not observed further south
• Increase in moisture convergence

11
Roll Observations
10 km

• ELDORA reflectivity and winds _at_ 400 m AGL

• 1.1 km in situ fields show rolls (?3.6 km) SE
  of TP

12
Preliminary results

• Mesolow may have aided in enhancing moisture
  convergence in CI region.
• Waves sampled by ground-based radar, satellite,
  in situ P-3, low-level MIPS w, ELDORA. Suggestion
  of Leandre II mixing ratio modulation caused by
  waves may be important for CI.
• Rolls observed near CI location with radar and
  in-situ P-3 may be important for CI.

13
GOES-11 Cloud Tracking

• 1st clouds formed along rolls
• Northern cloud formed near wave/outflow
  intersection

14
Ongoing work

• Closely examine ELDORA and Leandre II
  measurements near CI location
• Modeling study by Sophie Bastin (presented next)

15
Thank you.