Blacksburg VA (RNK) GPS Precipitable Water Project
Updated 9/12/01 by Steve Keighton (Science and Operations Officer)
PW Monthly Climatology for RNK and GSO
During the Summer (2000), the National Weather Service in Blacksburg, in cooperation with NOAA Forecast Systems Laboratory (Boulder), and Virginia Tech Dept of Civil Engineering, began a research effort to determine the impact of near realtime integrated precipitable water (IPW) measurements from a GPS sensor, on short term forecasting of flash flooding produced by convection. This has been approved as a COMET Partner's Project for FY 2001, titled "The Use of GPS Precipitable Water Measurements to Supplement WSR-88D Rainfall Estimates for Flash Flood Forecasting in Southwest Virginia". Specifically, we are comparing the temporal trends in the GPS IPW data with trends in convective activity in southwestern Virginia as observed by Doppler radar and satellite, to determine if short term trends or maximum values of PW provide any reliable signal in advance of flash flooding or rainfall rates that could produce flash flooding. We are comparing values of IPW with maximum observed radar reflectivity parameters and rainfall rate estimates, as well as observed rain rates at precipitation gages. We also plan on comparing the GPS IPW values with radiosonde measurements collected at the office, as well as values measured by the sounder instrument on the GOES-8 geostationary satellite. Preliminary results show evidence of some correlation in GPS IPW trends with the maximum rain rates as measured by radar, but several more events need to be examined. More results will be posted this spring or summer.
Below are links to some of these data sets that are available on line.
GPS IPW
Realtime GPS PW and Sfc Data
(from FSL) (only works with I.E.)
- predicted orbit method
- includes option to dowload ascii file by interactively choosing time
window
GPS PW post-processed - 30 hours
old (from FSL)
- slightly more accurate, not realtime
Other GPS PW Data Displays (UCAR)
GOES Sounder PW
GOES Derived Soundings - Choose RNK (NESDIS)
Latest GOES Sounder PW Image (Univ of Wisc - CIMSS)
GOES Sounder PW Loop (NESDIS)
Interactive GOES PW/LI/CAPE Trends (Univ of Wisc - CIMSS)
GOES Sounder PW 3-hr Trend Image (NESDIS)
00Z Raob - GOES Sounder PW Compare (Univ of Wisc - CIMSS)
12Z Raob - GOES Sounder PW Compare (Univ of Wisc - CIMSS)
Other GOES Sounder Products from NESDIS
GOES Images
Latest Eastern U.S. Visible Image (UCAR)
Latest Eastern U.S. IR Image (UCAR)
