Nashville, Tennessee

New AVIATION

• Medium to high rain chances spread area-wide on Sunday.
• Dry and cool for a few days before another high chance for a soaking rainfall middle of next week.

Showers are continuing to overspread the area this evening associated with a shortwave trough. These rain rates are very light and the nearest thunder is along the Gulf Coast. Expect this activity to increase in coverage throughout the day on Sunday, remaining at a steady drizzle. Forecast soundings depict a saturated profile through the column with very little instability. Combined with PWATs above the 90th percentile around 1.2", expect a steady widespread rain Sunday morning with occasional downpours and rumbles of thunder, especially west of I-65. The main impact from this rain will be a much cooler day on Sunday with temperatures even a bit below normal in the low 60s. After the shortwave and its resultant moisture pulls away, Monday looks dry and mild in between systems.

The majority of Tuesday is also in the transitional period awaiting the next weather maker. Dual low pressure systems are slated to eject from the Rockies on Tuesday morning: one with a trajectory over the Great Lakes and another with a track along the I-40 corridor. The southernmost surface low will be more impactful for Middle TN, but it looks like we are in the sweet spot in between favorable severe weather ingredients. The Great Lakes system will be displaced too far north to cause any impacts. Forecast surface analyses depict the southern system deepening to the point of occlusion by the time it reaches the Mississippi River on Wednesday morning, centered over west TN. This will help keep the axis of highest instability confined to the Gulf Coast during FROPA and limit our severe weather potential. Again, the main impact from this next system will be another good soaking for Middle TN. Storm total QPF probabilities of rainfall > 2" are about 50-60% per the LREF next week.

As the occluded low migrates off to the east on Thursday and Friday, wraparound showers from this same system will continue to impact parts of Middle TN for several days. Broad upper level troughing per the LREF supports much cooler temperatures (finally near normal in the mid 60s) and 20-40% PoPs through at least Friday morning. We finally dry back out on Friday evening but remain cool.

Widespread rain is causing CIGs to deteriorate and this trend will continue through the afternoon. CIGs at BNA, MQY, and CKV are forecast to drop to MVFR, but temporary reductions to IFR are possible between roughly 17-20z. The aforementioned terminals are expected to remain socked in with these lower CIGs through the period. Across the Plateau, CSV and SRB have a VFR TAF, but CIGs this afternoon and evening will be hovering around 3,500-4,500 ft. Rain will diminish after 00z, but another round is possible for CKV early tomorrow morning. Southeast winds will be 5-10 kt through the period with gusts up to 15-20 kt this afternoon and evening.

Nashville      63  52  73  58 / 100  40  10   0
Clarksville    62  52  73  59 /  90  50  20   0
Crossville     60  46  68  51 /  70  40  10   0
Columbia       63  52  73  58 / 100  30  10   0
Cookeville     63  51  71  57 /  80  40  10   0
Jamestown      63  49  70  54 /  70  50  10   0
Lawrenceburg   62  51  72  57 / 100  20  10   0
Murfreesboro   64  52  74  58 / 100  20  10   0
Waverly        61  53  72  61 / 100  50  20   0

None.