…Updated Aviation Discussion…
Issued at 1025 AM EST Tue Nov 15 2022
Current radar imagery reveals that the main band of precipitation has pushed east of a BWG-FFT line. With surface temperatures remaining nearly steady in the upper 30s to lower 40s, p-type is expected to remain as a cold rain for the rest of the day.
Elsewhere, low stratus and mist/drizzle will result in dreary conditions continuing through the afternoon. Overall, precipitation amounts have ranged from a Trace across southern IN and north- central KY to 0.2-0.3 inches from Lake Cumberland into the
Bluegrass. Any additional accumulations will likely remain below a quarter inch. Overall, forecast remains on track and have only made slight adjustments to bump temperatures a couple of degrees and tweak PoPs to reflect latest observations.
.Short Term…(Today and tonight)
Issued at 245 AM EST Tue Nov 15 2022
Light echoes are beginning to be picked up by KLVX this morning as moisture moves in from the southwest. A closer look from surrounding radars reveals much of this to be virga at this time, as drier low- level air evaporates precipitation falling from the mid-levels. Over the next couple hours, we’ll see the lower level saturate enough to result in precipitation reaching the ground.
Speaking of precipitation, the onset for the vast majority of folks looks to be in the form of a cold rain, but it’s possible we could see snow or a brief wintry mix for portions of southern Indiana and eastern Kentucky. Much of it will come down to how warm the lower atmosphere is when precipitation starts. The GFS and several of its ensembles result in temps cool enough to support snow or a wintry mix, while the NAM and various high-res guidance show a ‘nose’ of warmer air near 950mb to keep things as a cold rain. With recent AMDAR soundings falling more in line with the NAM and other high-res guidance (in support of a warm nose), have heavily trended the forecast in that direction, with only low-chance (20%) potential for snow or a wintry mix of some sort in our far north/east. Any wintry precipitation that does fall this morning should be very brief in duration and transition to a cold rain the remainder of the day.
Rain should gradually taper off from west to east this afternoon, but fog/mist will persist in its wake and keep temperatures from moving very much at all today. Some drier low-level air will begin working in from the west toward sunset to eradicate the fog/mist, but stratus will be persistent and continue into the overnight hours.
.Long Term…(Wednesday through Monday)
Issued at 312 AM EST Tue Nov 15 2022
The long-term will see a large upper trough parked over the eastern two thirds of the CONUS. This will push a couple of shortwaves through the Lower Ohio Valley Wednesday night and early Saturday. These disturbances won’t produce much more than a possible flurry or drizzle on Wednesday. For most of the week, temperatures will be 15 to 20 degrees cooler than normal.
A ridge of surface high pressure will stretch from Texas east, south of Kentucky. This will keep surface wind out of the west over the CWA much of the week. High temperatures will range from the mid 30s to low 40s through the weekend, but after the upper trough gets pushed to the east and zonal flow pushes a surface high east of the CWA, WAA from southern flow will lift temperatures into the 40s on Monday and low 50s on Tuesday. Low temperatures through the weekend will range from the mid teens to mid 20s in rural areas to near 20 to 30 in the urban areas.
On Wednesday, temperatures are expected to reach well above freezing as they climb into the low 40s, but the low levels, below 850 mb, will be saturated. This moist layer will remain below the DGZ, but may become thick enough at times to produce light flurries and/or drizzle. Either way, not expecting enough to cause any problems.
.Aviation…(18Z TAF Issuance)
Issued at 1235 PM EST Tue Nov 15 2022
MVFR to IFR conditions expected to prevail through much of the TAF period. Main band of rain is currently lifting through the Bluegrass and KLEX, although drizzle and mist will continue to be possible at all sites into this evening beneath the low stratus. Current expectation is that CIGs will improve to low-end MVFR at all sites except KLEX by 16/00Z, with KLEX lifting into MVFR by 16/06Z. Ceilings may then remain below 2 kft through much of tonight and into Wednesday morning before clearing out from west to east Wednesday afternoon, with a return to VFR conditions likely just beyond the end of the TAF period.