# Presentation: 526688

## Topographic Dependency of Rainfall Characteristics from the Sierra Madre Occidental in Northwest Mexico

**NERN Project Team: NCAR, U. Arizona, U. Sonora, IMADES, ITSON, NOAA-CPC, Hampton U.**
**29****th**** Annual Climate Diagnostics and Prediction Workshop**
**October 20, 2004**

## Outline of  Presentation:

- Brief overview of the precipitation event monitoring network in Mexico for the 2004 NAME-EOP
- Recent findings from the NERN with emphasis on the diurnal cycle
- Complimentary activities

## Slide 3

## NEXRAD Yuma

_**NEXRAD Yuma**_

_**NCAR SPOL**_

_**SMN Guasabe**_

_**SMN El Palmito**_

_**SMN Cd. Obregon**_

_**SMN Los Cabos**_

_**NEXRAD Tucson**_

_**NEXRAD El Paso**_

- Radar Umbrella Radius: Approx. 150 km

_**NEXRAD San Angelo**_

_**NEXRAD Midland**_

## NERN-Spol Radar Network:

*NERN-Spol Radar Network:*

## NAME Simple Rain Gauge Network

-  141 Gauges
-  Daily Reporting

## NERN Configuration:

- 87 Event logging, tipping bucket raingages
- 6 major W-E transects traversing SMO
- Major improvement in topographic and temporal sampling of precipitation
- Installed 2002-2003, in operation through spring of 2006
- Not available in real-time

- Contacts: gochis@rap.ucar.edu, watts@fisica.uson.mx,
-                 garatuza@itson.mx

## Slide 8

## Slide 9

## Slide 10

## Slide 11

**Notes:**
-We now have on the order of 1.5-2 seasons of data from the NERN for given stations...
-In agreement with some earlier studies the seasonal precipitation max is located along the 
“western slope” of the SMO, below the Plateau rim...
-I think it is important to emphasize the nature of the terrain transition as being a rim structure
bisected with deep complex canyons as opposed to a gently sloping mountain front... 
-This allows inland penetration of moisture into the low canyons which undergo very intense daytime heating...

## Slide 12

**Notes:**
-We now have on the order of 1.5-2 seasons of data from the NERN for given stations...
-In agreement with some earlier studies the seasonal precipitation max is located along the 
“western slope” of the SMO, below the Plateau rim...
-I think it is important to emphasize the nature of the terrain transition as being a rim structure
bisected with deep complex canyons as opposed to a gently sloping mountain front... 
-This allows inland penetration of moisture into the low canyons which undergo very intense daytime heating...

## NAME Physiographic Relationships

- 2002

- 2003

## Slide 14

## Precipitation Analyses: Diurnal Cycle of Precipitation Frequency

## Precipitation Analyses: Diurnal Cycle of Precipitation Frequency

## Slide 17

## Precipitation Analyses: Diurnal Cycle of Precip. Frequency

- Jul-Aug ’03 Transect Mean Diurnal Cycle

## Precipitation Analyses: Diurnal Cycle of Intensity

## Precipitation Analyses: Extreme Precipitation, Maximum Hourly Intensity

-  Popular theme: Jones et al. Extreme precip and MJO
- 		    Saha CFS extreme precip validation
- 		    Kunkel Extreme precip. 1895-2003
-  What is an extreme?  S. Saha “Large departure from
-     normal”    (>= 2, 1.5)

## Precipitation Analyses: Extreme Precipitation, Maximum Hourly Intensity

| Jul-Aug  2002-2003 |  |   |   |   |   |   |   |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Elevation Bands | Network | B1 | B2 | B3 | B4 | B5 | B6 |
| Elevation Band Interval (m) |  | 0-500 | 500-1000 | 1000-1500 | 1500-2000 | 2000-2500 | 2500-3000 |
| Number of Gages | 76 | 20 | 12 | 5 | 18 | 14 | 7 |
|  |  |  |  |  |  |  |  |
| Avg. Max. Intensity |   | 37.4 | 28.9 | 26.6 | 23.1 | 21.0 | 19.5 |
| Std. Dev. Max. Intensity |   | 19.8 | 9.2 | 21.4 | 8.7 | 5.5 | 6.2 |
| Abs. Max. Intensity |   | 78.5 | 43.2 | 47.3 | 38.6 | 31.8 | 32.5 |
|   |   |   |   |   |   |   |   |

## Slide 22

## 1-Day

- 5-Min

## Gulf Surges During 2003 – NERN Analysis

## Quantifying Uncertainty in QPE Products

-  Difference in monthly and
-   seasonal precipitation in
-   CPC daily gridded analyses
-   and NERN
-   Appear to be regions of
-    persistently high uncertainty
-   Useful a value-analysis of
-    NERN gauges in formation
-    of a long-term observing
-    network

## Complimentary Activities: Isotopic Analysis

-   Evaporation of falling rain appears to be significant only in the desert climate of the
-    three northwestern stations (Tucson, Mazocahui and Huasabas). Trend in O18
-    values from northwest to southeast is mainly a function of station altitude.
-   The samples generally plot close to the Global Meteoric Water Line (GMWL) but
-    do show evidence of some interannual variability

- (Courtesy of Chris Estoe, U. Arizona)

## NAME Community Archives

- Hydrological Data (NHWG-Action Plan)
- Daily Reports from the CNA from Sonora (and Sinaloa)
- Streamflow, reservoir levels, precipitation, pan evaporation
- Currently in Excel Spreadsheets
- Will be distributed via JOSS NAME Data Catalog
- WRF Modeling Archive
- Jul 1 – Sep 1, 2004
- 2x Daily 48-hr Forecasts
- GFS Initialization and Boundary Forcing
- 12 km horizontal resolution, 31 vertical layers
- Available to community via NCAR Mass Store (1.22 Gb)
- Photo Archive
- UCAR Digital Image Library (https://www.fin.ucar.edu/ucardil/default.jsp)
- NOAA Photo Library (http://www.photolib.noaa.gov/)

## Precipitation Analyses: Topographic Dependence of the Diurnal Cycle of Wet Day Rain Rate