Early during the week of September 20, 2010, a group of ABQ forecasters were viewing the CIRA Blended Total Precipitable Water (TPW) product. This is a regularly referenced product at NWS Albuquerque, especially during Monsoon Season. What caught our attention was the unusually high value of TPW over northern Mexico. Look for the area of purple on the image below from September 21, 2010. We noted that during our summer monsoon season, we had see “red” values of TPW (PW>2), but not “purple” (PW>2.5). Percent of normal TPW indicated values of >200% (yellow) over northern Mexico and southwest Arizona. Our confidence was high that we were soon to be affected by heavy precipitation event.
Twenty four hours later, New Mexico is, in fact, in the middle of a heavy precipitation event. Note the increase in TPW across New Mexico (more green and gold) and the 200% of normal over most of the state.
Our 00Z sounding from 9/23 had a PW of 1.46 – a record value for September and the third highest PW measured by our raob since 1948. The GPS-MET, that measures Integrated Precipitable Water every 30 minutes, nicely illustrates the record value as well:
While Tropical Depression Georgette contributed to the deep subtropical moisture plume, ample deep moisture ahead of Georgette and lift associated with an approaching upper level trough combined for wide spread heavy rain.
Precipitation amounts exceeded 2 inches across much of New Mexico. Some of the larger amounts are listed in the table below.