1 / 7

AMSU/MHS Snowfall Rate Product

NESDIS Snowfall Rate (SFR) Product Training Session Huan Meng , Ralph Ferraro NOAA/NESDIS December 5, 2013. AMSU/MHS Snowfall Rate Product. Satellite retrieved liquid equivalent snowfall rate (SFR) over land Need snow to liquid ratio to convert to solid snow

denton
Download Presentation

AMSU/MHS Snowfall Rate Product

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. NESDIS Snowfall Rate (SFR) ProductTraining SessionHuanMeng, Ralph FerraroNOAA/NESDISDecember 5, 2013

  2. AMSU/MHS Snowfall Rate Product • Satellite retrieved liquid equivalentsnowfall rate (SFR) over land • Need snow to liquid ratio to convert to solid snow • The ratio is dependent on the local climatology and environmental conditions such as surface air temperature and temperature profile • SFR uses data from microwave sensors: Advanced Microwave Sounding Unit-A (AMSU-A) and Microwave Humidity Sounder (MHS). The sensors are aboard fourpolar-orbiting NOAA POES and EUMETSAT Metop satellites • Each satellite orbits the earth 14 times a day. It takes 2-3 orbits to cover CONUS. • Each satellite passes a location up to twice per day in and below mid-latitudes, maybe more in higher latitudes. The two passes are about 12 hours apart. The four satellites provide up to eight SFR estimates, grouped into 4 morning overpasses and 4 afternoon overpasses, in a location in mid-latitudes per day. • SFR resolution is 16 km at satellite nadir and 26 km x 52 km at limb • Maximum liquid equivalent snowfall rate is 0.2 in/hr; minimum is 0.004 in/hr

  3. Product Applications • Identify snowstorm extent and the location of the maximum intensity within the storm • Provide quantitativesnowfall information to complementsnowfall observations or estimations from other sources (stations, radar, GOES imagery data etc.) • Fill observational gaps in mountains and remote regions where weather stations are sparse and radar blockage and overshooting are common • Locate snowstorms at higher latitudes where the quality of the subjective GOES IR and VIS imagery data deteriorates • Track storms and derive trending information (e.g. strengthening or weakening of the storm) by pairing with GOES IR/VIS/WV images to

  4. What to be Aware of • This is a liquid equivalent snowfall rate • There usually is a time lag between the retrieved SFR and the best correlated ground observation, due to the slow terminal velocity of snow particles • Satellite microwave signal can penetrate cloud, so SFR represents snowfall throughout the precipitation layer • The current product is limited to regions where the surface air temperature is about 22°F and above • Extension to colder climate is currently under development • Not applicable to lake effect snow • The resolution of the product is too coarse to detect the narrow snow band of lake effect snow • Misses very light snowfall due to a minimum SFR limit • Polar-orbiting satellite product with latency of 30 min – 3 hrs

  5. Use Case 1 – Tracking Snowstorm Hard to determine snowing clouds from GOES Difficult to tell rain from snow in radar SFR Product at 17:05Z Snow max later rotated and moved north Snow edge and max intensity easy to infer GOES IR image at 17:00Z Radar at 17:06Z • How do I use the SFR Product? • SFR adds additional information to radar and GOES data • SFR makes it easy to identify edge of snowfall and area of maximum intensity • The movement and strength of a feature identified in SFR can be tracked using radar or GOES imagery between SFR overpasses • In addition, radar and GOES images can also be used to infer storm trending information SFR Product at 19:40Z

  6. Use Cases 2 & 3 – Filling Radar Gaps Higher elevation rain does not appear on SFR product SFR retrieval over an area in radar gap during a snow event in Newfoundland, Canada on November 29, 2012 Mono Lake x Lee Vining x x x June Lake Mammoth Lakes NEXRAD Composite Reflectivity & SFR NEXRAD Composite Reflectivity Maximum snowfall rate zone (MSRZ) The MSRZ moved further north MSRZ moved further north 19:40Z

  7. Product Summary • SFR is liquid equivalent snowfall rate • SFR uses observations from microwave sensors aboard polar orbiting satellites • Eight SFR estimates a day grouped into 4 morning and 4 afternoon overpasses • Most important applications: • Identify snowstorm extent and area with the most intense snowfall • Fill gaps in radar coverage and ground observations

More Related