Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 300900
Area Forecast Discussion
National Weather Service Nashville TN
400 AM CDT Thu Mar 30 2017
1st phase of the upcoming storm system has yet to fill in across
western TN but solid coverage resides across MS and IL. Should see
some of the activity over MS reach our western most counties between
6am and 8am as the precipitation moves nne. As for the severe
potential, weakening is expected and we will probably only see
strong intensities, if that, for this 1st phase this morning. As
you move further east, the tstms will fall apart before reaching
Before I talk about the 2nd phase, we took a closer look at the
expected wind magnitudes for today and found that we are below
wind advisory criteria. Furthermore, ISC data does not indicate
support. Thus, we will cancel the wind advisory.
The 2nd phase of this system appears to be the greater threat.
Pre frontal forcing is quite apparent with the advancing surface
trough over western TN. But, as it moves east, over eastern
portions of the mid state, forcing appears to weaken a bit as the
sfc low to our north loses some of its n-s integrity and trends
toward more of a w- e elongation. That said, the more destructive
storms will be west of i-65, but severe weather is still
anticipated area wide.
It now appears that a delay in convective development may occur
until around the 2pm to 4pm window. At that time, isol/sct development
may occur across a large portion of the mid state but the
favorable forcing and instability axis will reside over western
middle TN in the middle to late afternoon hours. This will be the
favorable zone of severe weather. From there, the severe weather
threat will spread east reaching the i-65 corridor between 5 pm
and 8 pm, and then the Plateau between 8 pm to midnight. Straight
line wind damage, large hail, and isolated tornadic development
still remains possible.
Moving on, the upper trough axis will cross the mid state late
Thursday night, so shower chances will persist into Friday. A brief
break from the showers and storms will occur over the weekend. Then,
another potent storm system will impact our weather early next week.
Temperatures through the period will continue to run above normal
06Z TAF DISCUSSION.
VFR flight rules will continue through most of this period,
however, winds will start to pick up shortly after sunrise.
Southerly gusts of 20-25 kts will be common through the morning
and afternoon hours as a strong weather system approaches from the
west. TS are likely at all 3 mid-state terminals tomorrow evening,
but the timing of these storms is still in question due to a wide
range of model solutions. Have used VCTS to illustrate the
approximate timing of TS and will use the 12z issuance to try and
nail down the timing a little better.
.PRELIMINARY POINT TEMPS/POPS...
Nashville 80 52 65 44 70 / 70 100 20 10 0
Clarksville 77 50 61 40 67 / 80 70 10 0 0
Crossville 78 52 61 41 64 / 30 100 40 10 0
Columbia 78 51 66 45 72 / 70 100 10 0 0
Lawrenceburg 79 51 67 45 72 / 70 100 20 0 0
Waverly 78 51 64 42 70 / 90 60 10 0 0