Area Forecast Discussion
Issued by NWS Louisville, KY

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029
FXUS63 KLMK 071449
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1049 AM EDT Sun Jul 7 2024

.KEY MESSAGES...

*   Warmer today with dry weather and comfortably low humidity
    continuing.

*   Moisture associated with the remnants of tropical cyclone
    Beryl will move into the Ohio and Tennessee Valleys as early
    as Tuesday. Strong storms and heavy rainfall will be
    possible at times through the middle of the week, though
    forecast confidence in specific impacts remains low.

&&

.UPDATE...
Issued at 1049 AM EDT Sun Jul 7 2024

Seasonably warm and dry weather will continue today as high pressure
near the Indiana/Ohio border dominates the pattern. Some thicker
cirrus has been noted over southern Kentucky this morning but
sensible weather impacts are minimal. Still on track for temps
topping out close to 90 this afternoon, but humidity remains
manageable with dewpoints in the lower 60s. No changes planned.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 302 AM EDT Sun Jul 7 2024

This morning, 1017 mb sfc high pressure is analyzed over the Ohio
Valley, with a relatively dry air mass for early July spread across
central Kentucky and southern Indiana. Lower humidity in combination
with light winds and clear skies has allowed for efficient radiative
cooling, with temperatures already dropping into the mid 60s in
rural areas while the cities are in the upper 60s and lower 70s as
of 06Z. As we head toward sunrise, we`ll drop a few more degrees,
with most locations falling into the 60s and even a few upper 50s
possible. In rural areas and river valleys, surface moisture may be
sufficient for the development of patchy fog, and a few sites have
already observed visibility reductions early this morning. Any fog
should burn off quickly after sunrise, setting up mostly sunny skies
later this morning.

Today, predominant high pressure and an axis of unseasonably low PW
values along the Ohio Valley will allow for another warm and sunny
day across the region. High clouds from convection over the Gulf
States will provide some filtering of sunshine, especially along and
south of the Western KY/Bluegrass Parkways, while a diurnal cu field
would also be expected to develop during the afternoon hours. Winds
will be light due to the lack of a well-defined low-level
height/pressure gradient, with speeds only around 5 mph this
afternoon. Expect temperatures to climb 2-4 degrees higher this
afternoon given increasing 1000-850 mb thicknesses; highs should
range from the mid 80s to the low 90s. Dewpoints will continue to be
quite comfortable for July, as we should mix out into the low-mid
60s this afternoon.

Tonight, high pressure will begin to lift northeast as the overall
pattern begins to change thanks to the interaction between troughing
over the central CONUS and TC Beryl. However, substantial changes in
sensible weather should hold off until the daytime hours on Monday,
and another night of light winds, mostly clear skies, and seasonably
mild temperatures is expected.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 302 AM EDT Sun Jul 7 2024

Well...a very complicated forecast for late Monday into Wednesday
with Beryls track towards the northeast after landfall in Lone Star
State. The forecast is even more challenging as to the amount of
phasing of potent Nrn MS Valley trough.

Mon...
Low level moisture will begin to steadily return to the OH Valley
(after a wonderful weekend respite) as flow becomes solidly
southerly. Dew Points go from low 60s Mon morning into the upper 60s
and low 70s Monday aftn. Without much in the way of a forcing
mechanism in place, any convection that does develop will be
isolated in nature and across the Srn Tier of Ky over to the Lake
Cumberland region.

Depending on cloud cover...Monday might be close to heat advisory
levels. Time and cross sections showing a slug of moisture from 400
mb to 200 mb which should keep values in mid to upper 90s but a
sultry day with highs in low 90s. If clouds are less than forecast,
HIs will be over 100 F for sure.

Mon Night-Wed...

Forecast is very complicated and uncertain with the remnants of
Beryl. The 00z run has a westward shift with GFS and ECM and various
timing and speeds. This brings alot more rain into MO/IL and
eventually MI

The forecast shows a very rainy forecast timeframe, but suspect we
are overly pessimistic and likely will be drier than for that long
of a duration w.r.t to PoPS and rainfall amounts. However, there is
alot of uncertainty with tropical remnants.

Having said that, there appears to be a good set up for a potential
Predecessor Rain Event (PRE) ahead of the main circulation of Beryl
which will need to be watched closely. Right now that appears to be
in IL/W Central IN.


Thu and beyond...

Beryl and its associated moisture should lift out of the region by
Thursday or Friday, though we may still stay unsettled at times
going into the early weekend as the aforementioned central U.S.
trough is slow to move/lift.  However, with a 1018 mb sfc high
pressure over area on Thu...things will be much more subdued in
terms of convection. Cloud cover will move out early Thu morning and
temps will will respond and temps will warm up into the lower 90s by
next weekend.

Weather Tidbits...

July 8 1680...The earliest known tornado in the present day US
killed 1 person in Cambridge MA.

July 9 1982...A Boeing 727 crashed on take off in Kenner LA. Pan Am
759 took off during a thunderstorm and hit a strong microburst
killing all 145 on board and 8 people on the ground.

July 10 1913...The worlds hottest temperature of 134 F at Death
Valley CA.

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
Issued at 652 AM EDT Sun Jul 7 2024

Visibility reductions from fog/mist currently at HNB/BWG should end
quickly after sunrise over the next few hours, with a return to VFR
conditions expected by 13Z. Through the remainder of the daytime
hours today, there is high confidence in VFR conditions and light
winds as high pressure continues to hold in place over the region.
Wind speeds this afternoon should remain around 6 kt or less, with
winds weakening further around sunset tonight.

VFR conditions will continue into the evening and early overnight
hours tonight, with another round of temporarily lower visibilities
possible once again between 06-12Z Monday morning. Have gone ahead
and included this in the HNB forecast where there is relatively
higher confidence in fog potential at this time.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE...RAS
SHORT TERM...CSG
LONG TERM...JDG
AVIATION...CSG