-- Discussion containing changed information from previous version are highlighted. --
694
FXUS64 KMRX 011423
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1023 AM EDT Wed May 1 2024

...New UPDATE...

.UPDATE...
-- Changed Discussion --
Issued at 1021 AM EDT Wed May 1 2024

Recent satellite trends and surface observations show fog and low
stratus have really began to erode over the last half hour or so. A
few patches of dense fog may persist over the next 30 minutes but
the larger area impacts have subsided. As such, have allowed the
Dense Fog Advisory to expire as planned. Skies will continue to
improve into the afternoon with plenty of sunshine and above normal
temperatures expected. No real changes to the forecast have been
made. Just minor adjustments to better align hourly temperature
trends where fog/clouds has slightly slowed warming this morning.
-- End Changed Discussion --

&&

.SHORT TERM...
(Today and tonight)
Issued at 319 AM EDT Wed May 1 2024

Key Messages:

1. Dense fog this morning.

2. Warm temperatures this afternoon.

Discussion:

Dense fog has expanded quite a bit in the last few hours, especially
in northern sections. Southern sections seem to have fog mainly near
rivers and valleys, but this may continue to expand before sunrise.
Therefore, a Dense Fog Advisory has been issued for the entire area.
Fog will gradually lift between 13-15Z. Once this happens, we will
have full sun all day as high pressure will be centered overhead
through the lower to midlevels. This should warm temperatures into
the upper 70s to mid 80s in most spots. Fog will be possible again
tonight, but likely not as extensive as this morning, limited
mainly to near rivers and lakes.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 319 AM EDT Wed May 1 2024

Key Messages:

1. Continued normal to above normal temperatures into next week, and
a very warm day Thursday.

2. Unsettled pattern with chances for showers and thunderstorms
Friday through next Tuesday.

Discussion:

The upper level heights will continue to rise Thursday with some
very warm temperatures as upper level heights will be 1 to 2
standard deviations above normal and will keep above normal
temperatures through the last couple days of the week. High
temperatures Thursday may only be a few days below record high
temperatures for the date. The subsidence combined with ridging
aloft will allow very dry conditions Thursday afternoon. By Friday
increasing clouds and a chance of rain will move into the area.

Another area of upper troughing moves into the northern and central
states Friday into the weekend, A surface front has moved with a
surface low into the Canadian province of Ontario. An approaching
surface boundary will lead to increasing rain chances Friday into
the weekend. As the parent low is far to the north the boundary will
move very slowly east and rain chances Will linger or continue each
day. Rain chances increase Friday night and Saturday as the front
gets closer. The warm temperatures Friday will help fire off
thunderstorms and also Saturday. High precipitable water values as
high as 1.5 inches, will help precipitation to be more significant
but amounts still not expected to be not more than 0.50 to one inch
Friday and Saturday.

Still uncertainty for the end of the weekend and into the new week
as there are still differences in the long term models. A secondary
area of low pressure is forecast to develop along the front or west
of the forecast area during this time and be a focus for more
showers and thunderstorms from Saturday night through Sunday and
also Monday. Higher pressure will stay along the east coast and
southeast which will also keep a southerly flow of moisture across
the eastern Tennessee Valley each day. It will be an on and off again
pattern of convection and could linger all the way through Tuesday.
Temperatures are expected to remain near to above normal each day
but could be cooler if there is more cloud cover and shower and
storm coverage for the late weekend into Tuesday.

&&

.AVIATION...
(12Z TAFS)
Issued at 712 AM EDT Wed May 1 2024

Dense fog is affecting CHA and TRI this morning. TYS is reporting
a fog bank west of the runway, and the TAF will go with the
expectation that it will remain away from the airport. Fog should
lift between 13-15Z, with SKC and light winds the rest of the
period. Fog is expected again tonight, but mainly near area rivers
and lakes, and thus it is likely at TRI.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             85  59  88  65 /   0   0   0  10
Knoxville McGhee Tyson Airport, TN  82  56  87  62 /   0   0   0   0
Oak Ridge, TN                       83  57  87  62 /   0   0   0   0
Tri Cities Airport, TN              81  54  86  57 /   0   0   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
NC...NONE.
TN...NONE.
VA...NONE.
-- End Changed Discussion --
&&

$$

SHORT TERM...DGS
LONG TERM....TD
AVIATION...DGS