-- Discussion containing changed information from previous version are highlighted. --
174
FXUS64 KMRX 210522 AAC
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
122 AM EDT Fri Jun 21 2024

...New AVIATION...

.UPDATE...
Issued at 926 PM EDT Thu Jun 20 2024

Forecast on track this evening with no updates.

&&

.SHORT TERM...
(This evening through Friday)
Issued at 239 PM EDT Thu Jun 20 2024

A mostly sunny afternoon across the forecast area with temperatures
at mid afternoon in the mid to upper 80s to near 90. A drier airmass
is in place with scattered cumulus and dew points in the lower to
mid 60s. Current forecast will continue as is except a degree or
two warming for Friday. Upper ridge is still holding strong over
the mid Atlantic and Ohio Valley this afternoon. Winds are light
and variable as well and heat index values are only in the lower
90s at mid afternoon. For the next 24 hours the center of the ridge
shifts west and will be almost overhead Friday. Expecting
temperatures to be slightly warmer Friday but no significant
changes in the forecast. Heat index values will reach the mid to
upper 90s Friday afternoon.

&&

.LONG TERM...
(Friday night through next Thursday)
Issued at 239 PM EDT Thu Jun 20 2024

Key Messages:

1. Above average temperatures continue with strong ridging in place.

2. Increasing rain chances Sunday into early next week.

Discussion:

Anomalously high 500 mb heights will continue to bring subsidence
to the area through Saturday, leading to above normal
temperatures and dry, stable conditions. Some isolated, short-
lived showers and storms may be possible in the higher terrain
Saturday afternoon.

The upper ridge retrogrades and flattens across the Ohio Valley on
Sunday as a shortwave trough and associated surface front moves
eastward across the Great Lakes and Ohio Valley. Greater low level
moisture ahead of this trough/front and lower upper heights will
increase instability, with higher probabilities for showers and
thunderstorms starting on Sunday and continuing through the first
half of next week. The highest chance of precip appears to be Sunday
afternoon and Sunday night with the passage of the aforementioned
shortwave trough and surface front.

Behind this system, we will have a SW low level flow that will
maintain above normal temperatures with humid conditions on Monday
and Tuesday, along with a chance of diurnal showers and
thunderstorms. Models show a deeper trough that may bring higher
rain chances to the area in the Wednesday/Thursday time frame, with
potentially a break the the heat behind that system.

&&

.AVIATION...
-- Changed Discussion --
(06Z TAFS)
Issued at 116 AM EDT Fri Jun 21 2024

Removed fog from KTRI with the 06z TAF issuance. Guidance not
exactly bullish on it occurring, and there are still some FEW-SCT
low and mid clouds around. Don`t think the odds are zero but not
confident enough to keep it in. Otherwise, ridging aloft begins to
weaken somewhat today so expect to see quite a bit of CU around
this afternoon. Forecast soundings suggest this will be shallow,
so do not expect any SHRA/TSRA to develop. Winds will remain
light.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Chattanooga Airport, TN             94  72  95  73 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  93  71  94  72 /  10  10  10   0
Oak Ridge, TN                       93  71  94  71 /  10   0  10   0
Tri Cities Airport, TN              91  67  92  69 /  10  10  10   0
-- End Changed Discussion --

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$

SHORT TERM...
LONG TERM....DGS
AVIATION...CD