Lots of rain this weekend, potential for sever weather — then cold
The National Weather Service discussion reports: “Another slightly warmer day is expected on Saturday, although we will begin to see more clouds moving over the area. The next large-scale storm system will begin to affect the area Sunday. The closed upper-level low takes a southerly route over Sonora and Chihuahua before beginning to lift northeast into southwest Texas and southeast New Mexico. Precipitation will begin Sunday with a shortwave moving toward the Southern Plains in the southwest flow ahead of the primary low. Precipitation will become much more widespread and Sunday night and Monday as the upper low moves toward northwest Oklahoma with precipitation generally moving out Monday. 
“Forecast precipitable water values are near or even above 1.5 inches across much of the area overnight Sunday night with some bullseyes over 1.8 inches. SPC sounding climatology for mid November PW values for KOUN soundings show only three occurrences of 1.5 inch being measured this late in the year. So we are definitely on the high tail of the distribution and heavy rainfall will certainly be possible. There will of course be the question of where the heaviest axis of rain sets up though, so the axis of forecast heaviest rain will likely shift some over the next day or two.
“Another question for Sunday night will be the severe weather potential. The main issue will be how much instability can develop. The wind shear will be very high with a 110-115 knot 500 mb jet and a 60-75 knot 850 mb jet setting up over the area overnight Sunday night ahead of the upper low. At the moment, surface-based CAPE is not expected to be very high given the time of night and widespread convection. Explicit model forecasts are not very high with the elevated instability very far north into the area either, but if sufficient elevated instability develops, there will still be a lot of shear to organize even elevated storms given the very strong mid and upper level flow. 
“There will be a brief respite in active weather with the departure of this system on Monday night and Tuesday, but then a upper trough in western Canada digs and cuts off over the northern Plains with the trough moving over the area Tuesday night or Wednesday. Although the operational models are in fairly good agreement with the timing and evolution of this system, there is still a spread in the ensemble members with some members a little slower and farther southwest with the upper low. This still gives some uncertainty on timing, but also still provides at least a low chance of light snow in northern Oklahoma on Wednesday if the upper low moves over Kansas as opposed to Iowa/Illinois as a few (albeit a minority) of the ensemble members project. Will not mention anything on Wednesday, although will keep the mention for Wednesday night as surface temperatures cool… although it will still be primarily based on the low potential that the upper low tracks farther southwest than the current operational models forecast.”
