Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 241158
Area Forecast Discussion
National Weather Service Nashville TN
558 AM CST Fri Feb 24 2017
FOR 12Z AVIATION DISCUSSION.
.SHORT TERM...(Today thru Sun nt)
Sfc low over nrn MO will be moving ene today and will track across
the rust belt by tonight. A cold front will extend southward from
the sfc low and is expected to move across the middle TN area
between 6 pm and midnight tonight. In advance of this feature, a
warm and breezy day is in store. Omega fields are showing a good
deal of subsidence and thus, wind speeds should reach the 15 to 25
mph and gusty range for much of the area. Not quite expecting wind
advisory criteria to be met, however. Temperatures today will reach
well into the 70s and will reach 80 degrees at a number of locations
west of the Plateau. Record highs for this date will likely be set
Moving on, as we get toward 00z, forcing along the frontal boundary
will begin to increase as upper level energy begins to catch up to
the boundary. Showers and tstms will increase in coverage and
intensity once the forcing sector reaches i-65 and points east.
Omega fields will match up nicely with higher shear values and
better instability levels. Thus, strong to severe tstms are possible
across areas east of i-65 this evening. Otw, precip probabilities
will range from 80 percent across much of the east, down to 40
percent far west. Look for much colder air to work in behind the
front with temps by 12z Sat down into the the upper 30s northwest to
the upper 40s southern Plateau.
On Saturday, a few lingering showers will be possible early along
the Plateau. Otw, a cold day is in store with highs holding in the
40s with a northwest wind of 10 to 15 mph. The sfc high will park
right over the southeastern U.S. Sunday morning. So, with clear
skies expected, overnight lows will fall into the 20s area wide.
It`s been rather warm as of late, so any early season vegetation
revival will get smacked around with this freeze. But, being that
its February, this point will not be dwelled upon.
A warming trend will quickly commence on Sunday with highs in the
50s. Clouds and a returning chance of showers will keep low temps in
the upper 30s and 40s for Sunday night.
(Mon thru Thu)
An unsettled and unseasonal warm wx pattern will be in store for at
least the first part of next work week, with a more seasonal wx
pattern emerging as the second half of next work week progresses.
In taking a closer look, a weak upper level disturbance in a
continuance of SWLY flow aloft will move across the region Mon into
Mon night resulting in the potential for scattered light shwrs
across our area. This southwesterly flow pattern is expected to
continue thru at least Thu, before an upper level trough passage
occurs, resulting in, along with a sfc frontal passage during the
day on Wed, high pressure influences from the Rockies being able to
build into our region, resulting in dry conditions with a return to
seasonal normal temps. As we now take a closer look at Tue thru Wed
time frame, look for increasing instability and weak upper level
disturbances passages in flow aloft to result in sct to numerous
light shwrs Tue into Tue night with iso tstms also possible. Best
overall moisture, instability, and lift potential look to occur
across the mid state region as Wed progresses ahead of sfc frontal
passage, with sct to numerous moderate shwrs and sct tstms possible
during the day, with the potential of lingering post sfc frontal
moisture resulting in iso to sct light shwrs during the evening hrs
as upper level trough moves through mid state.
As for temps, afternoon high temps 5 to 10 degrees above seasonal
normal values are expected on Mon afternoon. Temps will warm to 15
to 20 degrees above seasonal normals on Tue, mainly in the upper 60s
to lower 70s, mid 60s Cumberland Plateau Region. Lows Mon and Tue
nights will be around 20 degrees warmer than normal also, mainly in
the low to mid 50s. With increasing atm moisture and associated
rainfall potential, highs on Wed will be only in the mid 60s, lower
60s Cumberland Plateau Region. Lows Wed night will be closer to
seasonal normal values in the mid to upper 30s, with highs on Thu.
near seasonal norms in the low to mid 50s, around 50 Cumberland
Plateau Region. As mentioned above, seasonal temps are expected
to continue into at least the first part of next weekend.
12Z TAF DISCUSSION.
Will continue to mention LLWS thru 24/15Z BNA/CKV and 24/17Z CSV.
Sfc pressure gradient should strengthen enough by these times to
results in wind speed thresholds much closer sfc to 2KFT ones.
Generally, sfc gusts to around 20kts expected 24/15Z-25/12Z.
Otherwise, best timing of shwrs/tstms associated with sfc frontal
passage 25/02Z-25/04Z CKV, 25/03Z-25/05Z BNA, and 25/05Z-27/07Z
CSV, with MVFR ceilings and IFR VSBYS expected. Used VCTS remarks
a couple of hrs before these time slots to alert aviation users
that shwrs/tstms will be moving/developing near respective terminals.
Especially at BNA/CKV, expecting conditions to improve rather
dramatically after line shwrs/tstms moves thru, with some
lingering light showers post frontal for a couple of hrs, then
VFR/SKC conditions. Low level moisture depth should be deep enough
to support continuance of MVFR ceilings CSV from 25/05Z-25/12Z.