tn discuss
Office: MEG
FXUS64 KMEG 121707
AFDMEG
Area Forecast Discussion
National Weather Service Memphis TN
1207 PM CDT Sat Jul 12 2025
...New DISCUSSION, AVIATION, FIRE WEATHER...
.KEY MESSAGES...
Updated at 1207 AM CDT Sat Jul 12 2025
- Scattered shower and thunderstorms chances continue with a 30%
to 50% chance each day. Some storms could produce heavy
rainfall and strong winds.
- Warm and humid conditions are expected across the Mid-South,
with high temperatures generally in the low to mid 90s and heat
index values in the low 100s. Heat index values could reach the
mid 100s by the middle of next week.
&&
.DISCUSSION...
(This afternoon through next Friday)
Issued at 1207 AM CDT Sat Jul 12 2025
Warm and humid weather is set to continue ahead of a
cold/stationary front currently across the lower Midwest. A
shortwave trough over the Great Lakes will continue moving east
with high pressure remaining over the Mid-South for the next
several days. Extending south through the Midwest, a
cold/stationary front currently sits just north of the region. As
highs swell into the low 90s this afternoon, storms will form
along and south of this boundary, posing a marginal damaging wind
threat. Storms are expected to be diurnally driven and gradually
weakening after sunset. Similar weather is expected tomorrow with
lower confidence in the coverage of damaging winds from afternoon
thunderstorms.
Into next week, ridging will remain in place over the southern
CONUS as upper troughing refuses to drop south of the Ohio River.
As such, highs will continue to climb moving through the week,
eventually reaching into the middle to upper 90s Wednesday through
the end of the period. Heat indices are expected to be rising in
tandem towards 105+ F which is increasing concerns for a Heat
Advisory later in the week, especially across Mississippi and
Eastern Arkansas. According to ensembles, PWATs will remain at or
above 1.75" through this portion of the period, suggesting
reasonably high confidence in daily scattered afternoon showers.
These rains could keep areas from reaching advisory criteria,
adding some complexity to the heat forecast through the end of the
week. However, this airmass will still be very hot and humid,
even if it is below a heat index of 105.
&&
.AVIATION...
(18Z TAFS) Issued at 1207 AM CDT Sat Jul 12 2025
A look outside shows convective development is well behind where is
was at this time yesterday. As such will delay the and PROB30
groups by a couple of hours. Southwest will prevail at JBR, MKP
and MEM through the TAF cycle, gusting to around 22kts this
afternoon, then weakening to 5-10kts overnight. Winds at TUP will
be lighter and a bit more southerly, especially tonight. Winds
will pick up to around 10kts again tomorrow, with another round of
convection after midday.
&&
.FIRE WEATHER...
Issued at 1207 AM CDT Sat Jul 12 2025
No fire weather concerns are anticipated through the forecast
period. Hot and humid weather will keep MinRH values above 40%
with winds gusting to around 20 knots through this afternoon.
Thunderstorms are expected this evening with a marginal threat of
damaging winds, which will gradually decrease in coverage after
sunset. Similar conditions are expected tomorrow through the end
of the forecast period.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...JAB
AVIATION...JDS
Office: OHX
FXUS64 KOHX 121740
AFDOHX
Area Forecast Discussion
National Weather Service Nashville TN
1240 PM CDT Sat Jul 12 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 1233 PM CDT Sat Jul 12 2025
- Rain and thunderstorms continue through the weekend, best
chances are in the afternoon/evening hours.
- Risk of severe weather is low, however, localized heavy rain,
gusty winds, and frequent lightning will be possible with
isolated stronger storms.
- Warmth continues into the work week, with 20 - 30% chance of
heat indices greater than 100 degrees.
&&
.SHORT TERM...
(Rest of today through Sunday)
Issued at 1046 AM CDT Sat Jul 12 2025
As of 15z, the radar is quiet across Middle Tennessee. There are
some scattered Cu that have developed along and east of I-65. This
is in response to a weak shortwave that is noted on water vapor
imagery. Behind the wave, PWAT values are notably lower with a
pocket in West Tennessee indicating values of less that 1.5" while
the plateau currently have PWAT values greater than 1.8". Visible
satellite shows a lack of Cu growth over West Tennessee due to
the drier sinking air. Looking at the 12z CAMS, the afternoon
storm activity is pretty suppressed over Middle Tennessee thanks
to this more convectively-hostile air. That doesn't mean we won't
see a couple of isolated storms pop up, but I feel like the CAMs
are onto something with the limited activity through the mid
afternoon. The one area we'll need to watch is the northwest late
in the afternoon and into the evening as storms develop over
northwest AR, eastern MO, and southern IL and push eastward. This
could move into our area after 00z and gradually weaken through
03-04z as it moves east.
A couple additional scattered showers and storms may develop
overnight as deeper moisture advects back into the area. Sunday will
see the potential for diurnal convection mainly after 17z. As far as
the potential for severe storms today and Sunday, outside the
isolated risk for a strong wind gust with storms moving into the
northwest this evening, I don't see much potential. Rainfall
could be heavy with some of the activity, but storm motions should
be around 20 mph which is progressive enough to prevent a flash
flooding threat. Highs today and Sunday will be in the mid 80s on
the plateau and the upper 80s to lower 90s elsewhere. Afternoon
heat index values will be around 100 degrees west of the plateau
each afternoon.
&&
.LONG TERM...
(Sunday Night through next Saturday)
Issued at 1046 AM CDT Sat Jul 12 2025
As we move into the next work week, we'll keep the diurnal storm
chances. Activity on Monday and Tuesday will be fairly scattered in
nature with Middle Tennessee along the northern periphery of the
upper high. The upper high may weaken some as we get into the mid to
late week period which will increase the diurnal activity. Highs
through the week will remain in the upper 80s to mid 90s with
afternoon heat indicies in the upper 90s to lower 100s. Overnight
lows will be in the lower to mid 70s.
&&
.AVIATION...
(18Z TAFS)
Issued at 1240 PM CDT Sat Jul 12 2025
AT BNA, VFR conditions to prevail over the next 24 hours. The lone
exception would be if a thunderstorm is able to move through this
evening. Confidence was not high enough to mention in the TAF at
this time as there should be a decaying broken line of storms
approaching from the northwest. Overall, it currently does not
look like this storm potential will materialize but will be
watching it. A few storms tried to develop nearby around noon, but
the best chances should remain east of the terminal through this
afternoon. Otherwise, expect light southwest winds with some high
clouds rolling in tonight.
VFR conditions to prevail at all TAF sites. Best chances for
storms are at KSRB and KCSV now through late afternoon, though
lightning activity has been lacking so prevailed VCSH due to lack
of current thunderstorm activity. Thunderstorm chances then shift
northwest, and have inserted a PROB30 TS mention at KCKV for a
broken line of storms expected to approach the terminal.
Otherwise, expect light winds and a few mid to high level clouds
moving through overnight.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 74 93 74 93 / 30 40 10 40
Clarksville 72 90 73 91 / 30 40 20 40
Crossville 67 86 67 88 / 20 40 10 40
Columbia 71 92 71 92 / 20 50 10 40
Cookeville 70 87 69 89 / 30 30 10 40
Jamestown 68 86 68 88 / 20 40 20 40
Lawrenceburg 70 91 71 92 / 20 50 10 40
Murfreesboro 71 92 72 94 / 20 40 10 40
Waverly 70 90 71 91 / 20 50 10 40
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Reagan
LONG TERM....Reagan
AVIATION.....Husted
Office: MRX
FXUS64 KMRX 121745
AFDMRX
Area Forecast Discussion
National Weather Service Morristown TN
145 PM EDT Sat Jul 12 2025
...New SHORT TERM, LONG TERM, AVIATION...
.SHORT TERM...
(This evening through Sunday morning)
Issued at 141 PM EDT Sat Jul 12 2025
Key Messages:
1. Scattered showers and storms will continue this afternoon and
evening. A few may become strong to severe. Primary concerns with
any strong to severe storm will be damaging winds between 40-60 mph
and isolated flooding.
Discussion:
Upper trough across the Midwest and Great Lakes will provide
enhanced forcing which will support scattered showers and storms
through this evening. Bulk effective shear still in the 15 to 20kt
range per model soundings and RAP analysis. Rap analysis on the SPC
meso page shows MLCAPE values around 2,500 J/kg through the
afternoon. This mix of instability and minor shear will allow storms
to be loosely organized, compared to typical summer-time pulse.
Basically, this just means that there is a better chance for a few
isolated strong to severe storms today compared to yesterday. The
main hazards will any strong storm will be wind gusts up to 60 mph.
The risk for isolated flooding also remains due to the high PW
airmass.
Coverage of showers and storms will decrease by sunset but a few
isolated showers and storms may linger through the night due to some
slight enhancement in the 500 mb vorticity. Also, patchy dense fog
is possible tonight across any location that receives rainfall today.
&&
.LONG TERM...
(Sunday through next Saturday)
Issued at 141 PM EDT Sat Jul 12 2025
Key Messages:
1. No change from previous forecast. Daily summer-time convection
continues through the long term. Still potential for increased
coverage by late week as a trough returns to the eastern U.S.
2. Hot conditions return as an upper ridges strength peaks in the
middle part of the work week. Heat indices in the mid 90s to near
100F will become more common across valley locations.
Discussion:
No real change to the long term. Upper trough will continue to
slowly pivot eastward Sunday through Monday with continued chances
for diurnal convection. Under weak flow, we will have limited
chances to see any severe storms. The best coverage each day will
continue to be focused along our high terrain areas. Expect heat
indices in the mid 90s to near 100F to become more widespread across
the southern and central valley by Monday, with values in the low to
mid 90s across northeast TN and southwest VA. The hottest days look
to be Monday through Wednesday. Slightly lower temps, back in the
upper 80s to low 90s expected thereafter.
Additionally, we are still keeping an eye on a late week trough that
has potential to bring increased coverage of afternoon shower and
storm activity across the area.
&&
.AVIATION...
(18Z TAFS)
Issued at 141 PM EDT Sat Jul 12 2025
VFR conditions through the period. However, brief MVFR are
possible if any shower or storm passes directly over a terminal.
Winds will generally be out of the west and less than 10kts,
outside of any thunderstorms. Very low confidence in fog forecast
overnight so will not include fog at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 72 94 73 95 / 10 40 0 30
Knoxville McGhee Tyson Airport, TN 72 91 72 94 / 10 30 10 30
Oak Ridge, TN 70 91 71 93 / 20 40 10 40
Tri Cities Airport, TN 68 87 68 89 / 30 50 20 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
AVIATION...
