With an unseasonably strong upper low approaching New Mexico, forecasters at NWS Albuquerque anticipated high elevation snow and widespread rain with relatively high QFP values for the period of 26-27 April 2015. A winter storm watch was issued at 400 am MDT on Saturday, April 25. Snow was forecast for the highest terrain across the northern and central New Mexico, but significant snow accumulations were expected late Sunday, April 26 through early Monday, April 26. Additionally, rain amounts in excess of an inch were expected across the eastern plains.
The GFE storm total snow from mid-day Saturday, April 25 is shown below. The forecast called for the most significant snow accumulations, just over a foot across the highest peaks, to occur over the Sangre de Cristo Mountains (just to the west of Interstate 25) and the higher elevations along the Colorado border north of Raton, NM. The watch was upgraded to a warning at 4am MDT on Sunday, April 26.
Widespread precipitation was reported during the overnight hours, with 3-.6in of rain in the Albuquerque metro area. The position of the closed low early on the morning of Monday, April 27 is shown below. Snow was still being reported at Angel Fire in the Sangre de Cristo Mountains, but the big story by this point was rain across the eastern plains.
Two Snowfall Rate products were received during the overnight hours around 3am MDT (09Z). The date/time stamp was not included on the images – the first shows SFR at 0838Z and the second at 0913Z. Both include metar observations from 09Z. Angel Fire is reporting snow, though in both images the SFR ends just north of the site. Raton is reporting rain and the SFR products both show the eastern edge of snow accumulations ending just to the west of Raton. Based on very high accumulations south of Angel Fire, the SFR product may be underestimating the area of active snow.
As is often the case, radar cover across the north central mountains is limited. The 0.5 reflectivity mosaic below is from 09Z, between the two SFR products above. Angel Fire is marked by the purple circle. Radar returns over the Sangre de Cristo mountains are greater north of Angel Fire. In eastern New Mexico, Tucumcari (blue circle) is reporting rain associated with the strongest radar returns. Rain continued through the daytime hours with numerous rainfall reports of over one inch. In fact, Tucumcari Aiport reported 1.50″ of rain, the 3rd largest 1-day total in April since 1941!
Snow accumulation reports did verify our forecast of over a foot of snow for this late season event. Determining snow records is more difficult since routine snow observations are few. Highest totals were received in the Sangres, with 18 inches observed at Black Lake, just south of Angel Fire. Smaller accumulations were noted over the San Juan and Jemez Mountains, areas which did not have a Winter Storm Warning in effect. The RGS Snow-Cloud product from April 28 shows new snow cover across much of the north central high terrain. Snow over the San Juan and Jemez Mountains (west of the Sangres) likely accumulated prior to the SFR products above.