# Presentation: 875393

## Fig. 1. June-July-August mean precipitation rates (mm/day). Model simulations are taken from 5-member ensemble averages and compared with the observation (NCEP US-Mexico daily precipitation analysis).

- Fig. 1. June-July-August mean precipitation rates (mm/day). Model simulations are taken from 5-member ensemble averages and compared with the observation (NCEP US-Mexico daily precipitation analysis).

## Fig. 2. Differences between nighttime accumulated (00-12Z) and daytime (12-24Z) accumulated rainfall amount. Rainfall is normalized by daily total in each location and indicated by percentage (%) scale. For the observation, the NCEP hourly precipitation data was analyzed over the recent 20 years (1983-2002). Negative area indicates more rainfall amount in nighttime.

- Fig. 2. Differences between nighttime accumulated (00-12Z) and daytime (12-24Z) accumulated rainfall amount. Rainfall is normalized by daily total in each location and indicated by percentage (%) scale. For the observation, the NCEP hourly precipitation data was analyzed over the recent 20 years (1983-2002). Negative area indicates more rainfall amount in nighttime.

## Obs

- GFDL
- NCEP
- NASA
- NARR

- Fig. 3. Surface elevation (meter) over the analyzed domain. Five grid boxes are defined for the analyses, which includes .South East (SE, 80-85W, 30-35N), Great Plains (GP, 95-100W, 37.5-42.5N), Rocky Mountains (MT, 105-110W, 37.5-42.5N), Arizona-New Mexico (AZNM, 107.5-112.5W, 32-35N) and North American monsoon region (NAME, 106-112W, 24-30N).

- Fig. 4. Hourly precipitation rate (mm/day) averaged over the five grid boxes and indicated by local standard time (LST). Thick solid lines indicate the observed HPD (black) and the Regional Reanalysis (grey, 3 hourly) and thick lines with filled circles are ensemble mean of each models. Thinner colored lines indicate the ensemble spread of the models.

## Fig. 5. Three-hourly variations of diurnal precipitation (HPD) and low-level wind anomalies (RR). Precipitations are accumulated for each three hour time window and normalized by daily total (%). Daily means are subtracted in the wind vector and unit is m/s.  

- Fig. 5. Three-hourly variations of diurnal precipitation (HPD) and low-level wind anomalies (RR). Precipitations are accumulated for each three hour time window and normalized by daily total (%). Daily means are subtracted in the wind vector and unit is m/s.

## Fig. 6. Same as in Fig. 5 except for the simulation by GFDL model. Wind anomalies are presented at 0.93 sigma level. 

- Fig. 6. Same as in Fig. 5 except for the simulation by GFDL model. Wind anomalies are presented at 0.93 sigma level.

## Fig. 7. Same as in Fig. 5 except for the simulation by the NCEP model. 

## Fig. 8. Same as in Fig. 5 except for the simulation by the NASA model. Wind anomalies are presented at 0.92 sigma level.  

- Fig. 8. Same as in Fig. 5 except for the simulation by the NASA model. Wind anomalies are presented at 0.92 sigma level.

## (a) RR

- Fig. 9. Low-level jet frequencies for the nighttime (06 and 12 UTC, top) and daytime (18 and 00 UTC, bottom) in (a) the Regional Reanalysis, (b) the GFDL model, (c) the NCEP model, and (d) the NASA model. The low-level jet criteria 1 of Bonner (1968) was used.

- (b) GFDL

- (c) NCEP

- (d) NASA

## Fig. 10. Three-hourly diurnal variations of convective available potential energy (CAPE) estimated from the Regional Reanalysis. Daily mean is subtracted from each grid point. The unit is KJ/kg. 

## RR

- GFDL
- NCEP
- NASA

- Fig. 11. Diurnal variations of CAPE for the five selected boxes.

## Fig. 12. Same as in Fig. 10 except the parcel is lifted at 700 mb in the CAPE calculation. 

- Fig. 12. Same as in Fig. 10 except the parcel is lifted at 700 mb in the CAPE calculation.

## (a) CAPE

- Fig. 13. Vertical-diurnal variations of (a) CAPE and (b) convective inhibition (negative buoyancy) in the Great Plains (100-95W, 37.5-42.5N). The NARR (JJA 1995) data set was used for the calculation and daily means are subtracted in both panels.

- Fig. 14. Vertical-diurnal variation of CAPE in three models.

- (b) Inhibition

## (a)

- Fig. 15. Longitude-time plots of rainfall composite in case of nocturnal rain (00-12UTC). Note that different rainfall criteria were applied to the observation (NCEP HPD) and models and those are indicated in each figure. (a) is for NCEP HPD (1983-2002), (b) GFDL, (c) NCEP, and (d) NASA model.

- (b)

- (c)

- (d)

## Fig. 16. Observed Rainfall Composite (1995, NCEP HPD) (a) all-day composite, and (b) nighttime LLJ day composite