Moisture Plume in Layers

Moisture plumes from the tropical Pacific can extend into the mid-latitudes, and the CIRA Layer Precipitable Water (LPW) product based on microwave (AMSU, MHS) and infrared (AIRS) sounding instruments from NASA and NOAA polar-orbiting satelliltes provides information on the amount of moisture in each layer.  Traditional total precipitable water (TPW) data only give part of the picture and Water Vapor (WV) imagery only captures the upper tropospheric moisture.  Note here how the GOES WV imagery from the NASA GHCC site agrees well with the values of 2-4 mm in the 500-300 mb layer between Hawaii and the west CONUS.

20130313_2100_sport_cira_west_lpw500to300hpa

500-300 mb Layer Precipitable Water by CIRA, 13 March 2013, 2100Z

20130313_2130_GHCC_GOESW_WV

GOES Water Vapor imagery from NASA GHCC site, 13 March 2013, 2130Z

In the images below, the surface to 850 mb layer shows a wide plume of 0.5 to 0.75 inches of PW extending from Hawaii to Washington and Oregon. Moving upwards, the 850 to 700 mb layer continues to show a wide swath of moisture (~0.25 to 0.5 inches) in this same area, with a sharp gradient to the east.  Lastly, the 700 to 500 mb layer shows a more narrow moisture swath, but still with values ranging from ~0.25 to 0.33 inches, and extending into the northwest CONUS. The observations of vertical distribution of moisture in data void regions can be compared to NWP models as well as applied to estimating the available moisture at low levels for potential precipitation and flooding events.

20130313_2100_sport_cira_west_lpwsfcto850hpa

Surface to 850 mb Layer Precipitable Water by CIRA, 13 March 2013, 2100Z

20130313_2100_sport_cira_west_lpw850to700hpa

850 to 700 mb Layer Precipitable Water by CIRA, 13 March 2013, 2100Z

20130313_2100_sport_cira_west_lpw700to500hpa

700 to 500 mb Layer Precipitable Water by CIRA, 13 March 2013, 2100Z

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