1.       Brian A. Colle*, Yanluan Lin*, Justin B. Wolfe*, W. James Steenburgh @, David E. Kingsmill +, Mark Stoelinga, and Chris Woods # *Stony Brook University / SUNY # University of Washington, Seattle, WA @ University of Utah, Salt Lake City + University of Colorado / CIRES Some Comparisons Between IMPROVE2 and IPEX Bulk Microphysical Verification       Brian A. Colle*, Yanluan Lin*, Justin B. Wolfe*, W. James Steenburgh @, David E. Kingsmill +, Mark Stoelinga #, and Chris Woods # *Stony Brook University / SUNY # University of Washington, Seattle, WA @ University of Utah, Salt Lake City + University of Colorado / CIRES

2. Motivation  MM5’s BMPs have been thoroughly verified and published for one IMPROVE IOP (13-14 DEC). What about other cases?  General improvement of BMPs will likely require microphysical analysis using other field data (IPEX, PACJET, CALJET, ….).  There have been no WRF verification of IMPROVE IOPs.

3. Great Salt Lake Great Salt Lake Desert Stansbury Mts Oquirrh Mts Wasatch Range SLC 50 km 1500 2750 3000 3250 2000 2250 2500 1750 Elevation (m) x KMTX IPEX IOP3: 12-13 February 2000 NOAA P3 Leg 1 Leg 2 Leg 4 Leg 5 Leg 3 NOAA P3 Stacks Cascade Range IMPROVE-2: 4-5 December 2001 COMPARISON OF IMPROVE-2 WITH RESULTS FROM IPEX

4. 4-5 Dec Simulation  Same setup as Garvert et al. (2005a).  HOWEVER NO FDDA -> using FDDA (GDAS analyses) degraded the forecast … too warm at low-levels, and too convective…  There is low-level wind sensitivity to PBL parameterization. Eta-PBL better.  Since NOFDDA was run, a comparison with WRF could be completed (using Hong et al. 2004 BMP for now, is exmoisg available??).

5. NCEP 850mb analysis 00 UTC 05 Dec 2001 Model 850mb forecast 00 UTC 05 Dec 2001 (12 hr forecast)

6. IR IMAGERY 23 UTC 04 Dec 2001

7. UW Sounding Comparison at 0100 UTC 5 Dec (model green, obs orange) MM5-MRF (winds too weak, too warm near surface) MM5-Eta (winds better) WRF-MRF

8. MM5-ETAMM5-MRF P-3 legs 2&3 (4km green, 1.33km orange) – Eta better wind speeds, 1.33km good vertical velocities leg2 leg3

9. WRF

10. MM5-Eta MM5-MRF Spol (0100 UTC 5 Dec) MM5-Eta has better qualitative precip structure agreement during flight

11.  MM5-MRF  MM5-Eta WRF-MRF Model 12-h precip (in mm) for 8-20 h

12. MM5-EtaWRF-MRF THE CLASSIC OVERPREDICTION NEAR CREST PROBLEM Model Percent of Observed Precipitation (8-20 h)

13. leg3 leg2 MM5-ETAMM5-WRF Assumes all P-3 particles are graupel (upper-bound for P-3), dry snow ~50% as much

14. IPEX: 1800 UTC 12 February 2000 Observed surface winds 1.33-km MM5 (sfc T and winds, 6 h) Colle et al. 2005 MWR in press

15. KMTX (2260 m, 1830 UTC) 1.33-km MM5 (2260 m) A B BA 1 3 4 2 5 6 km MSL

16. IPEX: 1800-0000 UTC Precipitation 1.33-km (6-12 h pcp in mm) 1.33-km % of observed

17. Model Cross Section and two P-3 legs at 1900 UTC -11 o C -5 o C Snow, graupel, and cloud water

18. Model vs. Observed (NOAA P-3) at 3800 m CrestWESTEAST Cloud water (g kg -1 ) Cross-barrier wind speed (m s -1 ) Snow (g kg -1 ) Vertical motion (cm s -1 ) Simulated Observed

19. Model vs. Observed (NOAA P-3) at 2800 m Cloud water (g kg -1 ) Snow (g kg -1 ) Cross-barrier wind speed (m s -1 ) Vertical motion (cm s -1 ) WEST EAST Simulated Observed

20. Summary  Preliminary analysis of 4-5 Dec IMPROVE-2 suggests similar problems to the 13-14 Dec IOP. There is precip overprediction near the crest associated with an overprediction of snow and graupel aloft.  Unlike 13-14 December, the exmoisg underpredicts cloud water over lower windward slope.  IPEX results are different than IMPROVE-2. Model underpredicted snow aloft and overpredicted cloud water. Why?? (CCN?, colder temps in IPEX?, …). IPEX results suggests need to confirm IMPROVE results in other regions.