-- Discussion containing changed information from previous version are highlighted. --
042
FXUS64 KMRX 011720
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
120 PM EDT Wed May 1 2024

...New AVIATION...

.UPDATE...
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.

&&

.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...
-- Changed Discussion --
(18Z TAFS)
Issued at 115 PM EDT Wed May 1 2024

Some stubborn low level cu continues to hold onto MVFR cigs at
TRI and rather uncertain to when exactly it may lift or scatter
out. Have continued the MVFR cigs for a few more hours but this
should eventually improve and lead to VFR conditions at all sites.
Fog should be more confined to bodies of water tonight into
Thursday morning and have limited mention of fog to TRI for this
reason. Winds will remain light throughout the TAF cycle.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Chattanooga Airport, TN             59  88  65  84 /   0   0  10  50
Knoxville McGhee Tyson Airport, TN  56  87  62  81 /   0  10   0  50
Oak Ridge, TN                       57  87  62  81 /   0   0   0  60
Tri Cities Airport, TN              54  86  57  82 /   0   0   0  40
-- End Changed Discussion --

&&

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

$$

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