Scientific Forecaster Discussion
fxus64 kohx 252034
Area forecast discussion
National Weather Service Nashville Tennessee
334 PM CDT Fri may 25 2018
Convection has fired this afternoon over western middle Tennessee,
along and just east of a low-level Theta-E ridge, with only
isolated thunderstorms further east. It was feeling like
summertime, with high humidities and afternoon temperatures
climbing through the 80s.
Expect a moist and unstable environment to remain over the mid-
state through the upcoming Memorial Day weekend, with scattered
showers and thunderstorms each day, mainly during the afternoon
and evening hours.
All models (and nhc) are currently bringing Tropical Storm
Alberto northward from the Yucatan this weekend, producing some
deteriorating weather conditons along the Gulf coastal areas, from
Louisiana over to northwest Florida. Middle Tennessee is not
expected to see any effects from Alberto, however, until the
Monday through Wednesday period. It's possible that monday's
shower and thunderstorm activity could actually be a a little less
than what we see on Saturday and Sunday, as a band of subsidence,
on the outer edge of Alberto, could push into our neck of the
Woods. However, since the exact position of any subsidence band is
still highly uncertain, we'll keep at least a 30 to 50% pop
running that day just to take care of any diurnal activity that
might pop up. In addition, it's always a bit difficult to know
exactly when the first spiral band of convection might make it into
southern parts of the mid-state. It's possible we could see such
precipitation arrive over our eastern and southern areas as early
as late Monday afternoon or evening.
As the remnants of Alberto push northward from the Gulf Coast
across the Tennessee Valley, on Tuesday and Wednesday, our rain
chances go up. A lot of the activity will probably be diurnal in
nature. Therefore, have gone with widespread likely pops Tuesday
and Wednesday during the daylight hours, and chance pops at night.
As with all tropical systems, we'll also have to keep an eye on
the amount of rainfall that comes in with Alberto toward the
middle of next week, and whether or not some of the thunderstorms
will train across certain areas (as is common with tropical
systems.) The good news is that, as of right now, it looks like
the system will be progressive and move on through after a giving
US a day or two of widespread showers.
By late next week, the remnants of Alberto should pass north and
east of the mid-state, with a return to mainly just chance pops by
Temperature-wise, we should have sufficient sunshine each day of
the Memorial Day weekend to allow highs to top out in the 80s,
with nashville's high expected to reach 87 or 88 degrees each day.
However, as clouds and showers increase during the middle of next
week, you can expect highs to sink back into the upper 70s to
middle 80s most areas on Tuesday and Wednesday. As drier weather
returns late next week, highs, once again, rebound into the middle
80s to around 90.
18z taf discussion.
Radar trends show convection beginning to fire at 17z, with cells
noted over the southewestern portions and over the plateau. Hrrr
run shows the activity over the southwest is expected to push to
near ckv, bna, and mqy over the next couple of hours, with
activity also expected to develop near csv shortly. This could
yield some MVFR visible and ceilings at times so amendments should be
expected. This convection will give way to just vcsh during the
overnight and early morning hours, which may persist through the
Preliminary point temps/pops...
Nashville 68 88 68 88 68 / 30 50 40 50 30
Clarksville 67 86 68 87 68 / 40 50 40 40 10
Crossville 65 82 65 82 64 / 40 60 60 60 50
Columbia 67 86 67 86 66 / 30 50 40 40 40
Lawrenceburg 66 85 67 85 65 / 40 50 50 50 30
Waverly 67 85 67 86 67 / 40 50 30 40 20