489
FXUS64 KOHX 050037
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
737 PM CDT Fri Apr 4 2025

...New UPDATE...

.KEY MESSAGES...
Updated at 730 PM CDT Fri Apr 4 2025

- Major Life-threatening flooding may develop for northwest Middle
  Tennessee late Saturday through Sunday morning. Additional
  rainfall of 3 to 5 inches will be common with localized 8 inch
  amounts. Additional rain will quickly aggravate existing flood
  conditions and produce new flash flooding. Emergency personnel
  and resources should be ready to activate for evacuations and
  water rescues. River levels will remain elevated into next week,
  including the Cumberland and Duck Rivers.

- Severe thunderstorms will be possible again Saturday afternoon
  and night. Damaging winds, large hail, and torrential downpours
  will be the main features, and there will be a risk for
  tornadoes.

&&

.UPDATE...
Issued at 730 PM CDT Fri Apr 4 2025

We`re enjoying a nice lull in activity again this evening. This
gives everyone a moment to catch their breath because we`re going
to be in it again tomorrow. I`m going to hit on that with the full
package later this evening, but I wanted send out something real
quick saying the forecast is on track. We should remain relatively
rainfree until first thing tomorrow morning, so take the time to
rest because the severe and flooding threat will return tomorrow.

&&

.SHORT TERM...
(Rest of today through Saturday)
Issued at 1215 PM CDT Fri Apr 4 2025

This Friday morning not much was happening with the wx across
Middle Tennessee, and that was great news! The storm-weary,
water-logged northwest half to two-thirds of the area has
experienced widespread 4 to 6 inch rainfall totals over the past
couple of days and there have been pockets of generally minor
damage from severe thunderstorms and possible tornadoes. Our
southeast areas have no idea what the fuss is all about. Locations
like Crossville and Manchester have been rain and storm free
during this time.

The general setup remains the same as we have talked about for the
past several days. A quasi stationary boundary was set up along
the Ohio valley back to th ArkLaTex. This boundary has been and
will continue to be the focal point for heavy rain and severe
thunderstorms, mainly to our northwest today, then across our
coverage as it finally moves eastward Saturday through Sunday.

Here in Middle Tennessee, we are enjoying a midday friday break
from the active wx thanks to a pivot in the boundary which has
lifted the bulk of the active wx up to our north and well off to
our west. We are under a very warm and muggy regime on the
southeast side of this main boundary with influence from a strong
pressure ridge off the southeast coast. Things will probably not
go crazy in terms of coverage this afternoon and tonight, but we
will see some scattered storms re-develop, especially in our
northwest counties as residual low level boundaries from previous
storms become active again. Our northwest half is under a slight
risk (level 2 out of 5) with all severe modes possible. Our
southeast areas are not under any severe risk from the SPC and
will likely stay dry and warm today through tonight.

The main times of concern for this forecast period will come
Saturday afternoon through Saturday night as the frontal system
that has been stalled out to our northwest finally gets kicked
eastward. This will spread rain and storms across all of Middle
Tennessee, with more heavy rain and storms for areas that have
been suffering, and fresh rain and storms for our southeast areas
that have enjoyed several days of warm and dry conditions.

For the daytime hours Saturday, the main focus will be over the
northwest half of the area with the greatest coverage of heavy
rainfall and possible severe storms. Damaging winds will be the
main storm risk, but we will continue to have enough favorable
wind shear for a tornado risk.

Saturday night will bring widespread heavy rain and potential
severe storms across all of Middle Tennessee. The heavy rain and
flooding will be the main story. Late Saturday through Saturday
night precipitable water values will climb over 1.6" which is
above the climatological maximum for the date and 3 to 4
standard deviations above normal. The saturated atmosphere
combined with intense vertical motion and strong instability
throughout the atmospheric column will lead to extreme heavy
rainfall rates. For Saturday through Saturday night, our
northwest half is expected ot receive another 3 to 5 inches of
rain, but local additional totals over 8 inches will be possible!
Our southeast counties will have 2 to 3 inches will some locally
greater totals. Our northwest half will have areas of major flash
flooding and additional rises on rivers. Life threatening flash
flooding may lead to numerous evacuations and water rescues.
Emergency personnel and resources across northwest Middle
Tennessee should be prepared for activation Saturday afternoon
through Saturday night.

&&

.LONG TERM...
(Saturday Night through next Friday)
Issued at 1215 PM CDT Fri Apr 4 2025

Rain and embedded thunderstorms will linger throughout Sunday.
The intensity of everything will be lower, but any existing
flooding will be maintained by moderate downpours.

Rain will finally shut off as drier, much cooler air comes in for
Sunday night. We continue to look for cool and dry wx Monday
through Wednesday. The air will be cool enough for frosty
conditions with some freezing temps Monday night and Tuesday
night. Rivers across the north and west sections will be running
high.

&&

.AVIATION...
(00Z TAFS)
Issued at 643 PM CDT Fri Apr 4 2025

Area showers and thunderstorms have diminished, or moved north
into KY. So, Middle TN airports are clearing out at this time with
VFR conditions. Breezy southerly winds will prevail overnight,
generally ~10 kts with gusts ~20 kts, with a few clouds around.
VFR should persist through ~12z, but clouds will increase. Clouds
cloud increase ~09z at CKV.

For tomorrow, additional showers and thunderstorms are forecast to
move in from the west along a front. This will become slow moving
as it near BNA. TSRA conditions could pe.rsist at CKV for several
hours. Eastern airfields (SRB, CSV), should stay in the best shape
overall. Any convection tomorrow will bring the threat for gusty
winds and at least brief IFR conditions. Strong to severe TSRA
could also occur mid to late afternoon, potentially persisting
into the next TAF cycle.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      70  83  54  62 /  30  70 100  90
Clarksville    67  77  49  55 /  40 100 100  80
Crossville     65  82  57  65 /  10  30 100 100
Columbia       69  84  54  64 /  20  60 100  80
Cookeville     67  83  56  64 /  20  40 100 100
Jamestown      66  83  54  65 /  20  40 100 100
Lawrenceburg   70  84  56  65 /  20  50 100  90
Murfreesboro   69  86  54  65 /  20  50 100  90
Waverly        67  78  48  56 /  30  90 100  70

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Sunday morning for TNZ005>011-023>031-
056>060-062-093.

&&

$$

UPDATE.......Unger
SHORT TERM...13
LONG TERM....13
AVIATION.....Sizemore