First re yesterday - there were a couple of small thunderstorms in the east metro early last night and several ALERT gauges caught light, but measurable rain. Here I watched a bit of lightning around 9:30 pm MST.
The 06 UTC runs yesterday of both WRF variants, while in agreement in their model world, were way off in their forecasts of heavy storms after midnight. There was very little activity period for eastern Pima County yesterday. However, there is another nocturnal MCS over and east of the central GoC - IR image below from 6:00 am this morning.
The morning 500 mb analysis above (from SPC) shows that the anticyclone has weakened some as heights are lower around the center, which is over the lower Colorado River Basin. A weak inverted trough, or deformation zone, continues from the southern GoC northward across New Mexico. This feature is present only in the 700 to 500 mb layer, but model forecasts do try to inch it westward today.
This feature is very moist - as per the SPC morning skew-T plot for El Paso below.
The PW within the 700 to 500 mb layer (above from MIMIC at 13 UTC) shows this region of high moisture over southwestern New Mexico, our region and and southward into Mexico. The TWC 12 UTC skew-T below is drier in the BL than is El Paso and winds are easterly. However, with deep moisture the east winds won't be as drying as they are usually. The wind shear profile is quite favorable for strong and organized thunderstorms.
Bot 06 UTC WRF variants forecast late afternoon storms for central and eastern Pima County. The NAM version again forecasts another round of very strong storms across the metro area after midnight. That version forecasts development of a moist, absolutely unstable layer aloft after midnight, but the GFS version does not. This kind of unstable structure is often associated with our early morning MCSs - so we will watch all of this evolve today with higher hopes for rain.
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