Tuesday afternoon we cracked the 80s for the first time this year.
As a southerly flow increases, humidity levels will increase by the end of the week.
As a cold front approaches there will be two time periods of concern that we will watch for the possibility of some strong or severe storms:
1) Thursday afternoon
2) Then overnight, early Friday morning between 3am and 9am (timing could change slightly).
Right now the biggest threat would be for damaging winds and hail, but isolated tornadoes are also possible.
Details for weather geeks:
On during the day on Thursday, a complex of storms should be moving along a stationary front near the Ohio River. Some of these may extend southward to Middle TN, with the possibility of outflow boundaries emitted from the Ohio River complex. See Graphic #2.
Early Friday morning between 3-9am the cold front will arrive with a line of storms. Even though this will occur during the minimum amount of heating, there could be enough shear to produce severe storms. See graphic #3.
Cape: NAM: 1,000-2,000 j/kg. GFS: 500-750 with up to 1,500 j/kg west of Nashville.
0-500mb Bulk Shear: NAM: 40-55 knots. GFS: 40 knots.
0-3 km Helicity: NAM: 150-200 m2/s2. GFS: 150-200 m2/s2.
Friday early morning:
CAPE: NAM: 500-750 j/kg, some 750-1,000 j/kg west. GFS: 500-750 j/kg.
0-500 Bulk Shear: NAM: 40-50 knots. GFS: 55-70 knots.
3 km Helicity: NAM: 150-200 m2/s2. GFS: 250-450 m2/s2.