OLYMPEX An “integrated” GV experiment Physical validation—Precipitation Measurement—Hydrology November 2014-January 2015 PMM Science Team, Seattle, 2 November 2010

Contributors W. Peterson R. Cifelli T. Schneider D. Lettenmaier N. Voison N. Schraner J. Lundquist S. Medina S. Brodzik

Annual average precipitation (PRISM) The Olympic Peninsula is a “natural laboratory” for precipitation studies Huge precipitation amounts Annual average precipitation (PRISM) Maximum

Detailed Climatology 5-yr MM5 Nov-Jan precipitation climatology (mm) Only the climatology is verified by gauges--not individual events Verified by gauges: Minder et al. 2008

Low 0ºC level RAIN at low elevations, SNOW at higher levels Frequency of occurrence 0°C level (km) Distribution of Nov-Jan 0°C level for flow that is onshore and moist at low levels (KUIL sounding) Mean 0°C level during storms = 1.5 km See this full range in individual storms! See this in nearly every storm Plot provided by Justin Minder

Persistent southwesterly flow during the winter MOISTURE “Atmospheric River” NCEP long-term mean sea level pressure (mb) for winter (December to January) and topography

Persistent southwesterly flow during the winter Monday morning

Persistent southwesterly flow during the winter Monday morning

NWS WSR-88D radar to be in place ~2012

NOAA Mobile Atmospheric River Monitoring System Westport, WA since 2009 Data from vertically-pointing S-band radar Signal-to- noise ratio Height Radial velocity Height Time

UW fine-scale observing network across a southwestern Olympics ridge Detailed gauge network Minder et al. 2008

Real-time Regional Environmental Modeling (ESRL, UW) Atmospheric forecast UW/WRF Ensemble mode 1.33 km resolution Data assimilation Also NOAA ESRL

Real-time Regional Environmental Modeling (ESRL, UW) Hydrologic prediction UW ESRL WRF drives hydro model, predicts streamflow for all these watersheds, example is fcst for quinault for different versions of the model

Proposed OLYMPEX layout

(Global Hawk?) +NSF Facilities!!?? SNOTEL RAWS S-Band profiler Atmos. River Observatory NPOL WSR-88D Quillayute Rawinsonde

Physical validation of rain and snow retrievals (i.e. are physical assumptions in GPM algorithms robust under different conditions) Rain-snow transition on sloping terrain Melting layer effect on algorithm performance Different storm sectors—prefrontal, frontal, postfrontal Different surface conditions—ocean, land, coast, hills, mountains

Rain and snow measurement (i. e Rain and snow measurement (i.e. validation of its accuracy from satellite instruments mounted on aircraft) Do precipitation measurements transition accurately from ocean to land land to mountains? Do they handle the orographic enhancement of precipitation? Can satellite rain measurements be downscaled accurately relative to the topography?

Hydrologic applications (i. e Hydrologic applications (i.e. testing whether GPM data can improve streamflow forecasting in complex terrain) Can satellite rain estimates over hills and mountains provide useful input to real-time hydrologic forecasting? Does downscaling relative to topography improve hydrologic forecasting? Can assimilation of satellite rain estimates into regional forecasting models improve hydrological forecasts? Change operational to real time, change streamflow to hydrologic (need to get interior streamflow points & snowpack as well as stream output Assimilation is more physical

OLYMPEX is a fully integrated GV experiment Summary OLYMPEX is a fully integrated GV experiment Physical validation Rain and snow measurement Assimilation of GPM measurements into hydrologic forecasts Change operational to real time, change streamflow to hydrologic (need to get interior streamflow points & snowpack as well as stream output Assimilation is more physical The climatology, terrain, and existing infrastructure have all the ingredients for hosting an integrated campaign

End This research was supported by NSF grant ATM-0820586 and NASA grant NNX10AH70G