Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 261155
Area Forecast Discussion
National Weather Service Nashville TN
555 AM CST Sun Feb 26 2017
FOR 12Z AVIATION DISCUSSION.
(Today thru Tues nt)
Sfc high located directly over the mid state this morning. Skies are
clear, winds are light and current temps are generally in the 20s.
By late this afternoon, the sfc high will be located along the
Carolina coast. A southerly return flow is expected, and with 850 mb
temps on the rise, highs today will reach into the 50s.
Tonight, a sfc trough will develop and drop slowly southward. This
feature will persist across the mid state on into Monday. As a
result, likely shower chances will return.
The unsettled pattern continues on Mon nt and Tues as impulses move
across the area. Models appear to be a bit overly bullish so will
undercut the pops a bit. But, we do see some increasing instability
levels by Tuesday, will therefore be sure to include thunder at
that time. Prefrontal forcing and an increasing amount of
instability will occur on Tues nt. A few strong storms will be
For the near term temps, into the 50s we will go as mostly sunny
skies prevail today. Not as cold tonight as clouds increase. 50s
again for highs on Monday with showers around. On Monday night, the
southerly flow will increase and temps will drop little. Low 70s on
Tuesday as prefrontal influences begin to encroach from the west.
(Wed thru Sat)
Enhanced overall moisture, instability, and lifting potential looks
to occur across the mid state region as Wed progresses ahead of a
potentially strong sfc cold frontal passage, with numerous moderate
shwrs and tstms possible during the daylight hrs. A copious
assortment of derived atm indicies, along with projected model
consensus strong low level jet dynamics, all point to the potential
of some strong to severe tstms as the daylight hrs progress on Wed
along and ahead of this potentially strong sfc cold frontal passage.
As of this time, SPC`s Day 5 Severe Weather Outlook as much of the
mid state in a 15% outlook area for severe thunderstorms. Of course,
further model runs will need to occur along with further
meteorological interpretation for a clearer understanding of the
potential of svr wx across the mid state region during the daylight
hrs on Wed, but will at least mention initially this potential in the
morning HWO issuance, along with the possibilty of strong tstms
occuring on Tue night.
Otherwise, the potential of lingering post sfc frontal moisture
resulting in iso to sct light shwrs during the evening hrs will be
possible as an upper level trough moves through the mid state
region. The later half of the work week into the weekend will be
dominated by dry conditions per building ridging influences moving
out of the Rockies and settling across the mid state region
providing moclr skies and cooler conditions.
As for temps, with increasing atm moisture, highs on Wed will be in
the upper 60s to around 70. As CAA builds in behind above mentioned
strong sfc frontal passage, lows Wed night will be closer to
seasonal normal values mainly in the upper 30s. Afternoon highs and
overnight lows during the Thu thru Fri time frame will be near
seasonal norms. As sfc high pressure influences eventually shift
eastward by Sat, a WAA pattern will develop resulting in high temps
warming into the low to mid 60s, upper 50s to around 60 Cumberland
Plateau Region, with lows in the upper 40s to around 50, mid 40s
Cumberland Plateau Region by the end of the weekend.
12Z TAF DISCUSSION.
Increasing high level cloudiness spreading from west to east is
expected through 27/00Z ahead of an approaching weak upper level
disturbance. This weak upper level disturbance will move into the
mid state region from 27/00Z onward, resulting in an overall
increase in atm moisture potential with a transition from VFR
altostratus to VFR stratus ceilings 27/09Z BNA/CKV. Light shwrs
are expected to develop at both these terminals also before
27/12Z, resulting in MVFR VSBYS due to this light rainfall and
fog development at both of these locations too.