Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 020704

Area Forecast Discussion
National Weather Service Louisville KY
304 AM EDT Fri Jun 2 2023

.Short Term...(Today and tonight)
Issued at 254 AM EDT Fri Jun 2 2023

Currently, a closed upper low over an axis of surface high pressure
sits over the Great Lakes. This is driving northeast flow at all
levels through the Lower Ohio Valley. Satellite imagery is showing
clear skies over the CWA, but under a strong near surface inversion,
radiative cooling is causing fog to develop in areas that saw
precipitation yesterday.

Once the sun rises, temperatures are expected to quickly begin
climbing, causing fog to dissipate quickly. Precipitable water
values between 1 to 1.25 inches across the CWA will drop to around
0.5 to 0.75 inches this evening due to the dry air advection. Dew
points will drop from the upper 50s (NE part of CWA) to upper 60s
(SW part of CWA) down to the upper 30s (NE part of CWA) to mid 50s
(SW part of CWA). The point being, we are drying out. This will keep
skies cloud free for most in the region, but it will also drive
higher temperatures. Temperatures were bumped up slightly over NMB,
but with northeast winds around 5 to 10 mph and some gusts to near
15 mph, didn`t want to get too carried away. Believe most will see
the low 90s today with a few upper 80s in the eastern Bluegrass and
Lake Cumberland regions. Relative humidity levels could drop into
the upper teens over the northeastern half of the CWA given the high
temperatures and low dew points. The drier air will help the warmer
temperatures not feel as bad as compared to the higher humidity the
Ohio Valley usually sees with temperatures in the upper 80s and 90s.

Tonight, influence from the high pressure system will ease winds and
allow efficient cooling. Expect temperatures to fall into the low
to mid 60s for most with a few cooler locations seeing the upper


.Long Term...(Saturday through Thursday)
Issued at 220 AM EDT Fri June 2 2023

Well...overall the medium range is characterized by above normal
temps and mostly dry thru Mon. The long term will have a slightly
cooler airmass for Tue-Thu.

Main synoptic features are dominant ridge over Great Lakes with
omega blocking pattern with upper lows over Eastern Canada and
British Columbia. Through time the ridge pushes west into Nrn Plains
and Manitoba with a deep low over Quebec (2-3 SD) pushes into New
England.  This will bring a true cold front (hints of a backdoor
cold front) into the Ohio Valley.


With strong ridging, Sat will be toasty and maybe the warmest day of
the year. The pioneered Massie Rose 1000-850 mb thickness technique
brings 91-94 F for highs. Saturday should be the warmest day of the
extended. The GFS has deeper llvl moisture and higher sfc dew pts,
whereas the ECM is much drier. This obviously has a big impact on
the amount of instability for weekend afternoon showers and storms.
Leaning ECM. Still will have very isolated storm or two both
afternoon/evenings, especially with the upper ridge shifting wwd.


Very unusual synoptic pattern with vigorous upper low moving
southwestward bringing troughing to the Ohio Valley. This will bring
increasing (slightly) shower and storm chances returning in advance
of the front. The llvl moisture is marginal and forcing is
sufficient to bring 20-30% coverage Tue-Tue night. However, the
exact position and track of the mid and upper level low is the crux
of precip chances.

Once the cold front passes, a drier and more stable air mass will
overspread the region for the middle of next week. The deterministic
guidance has upper 70s for zeniths, but unless areas gets more rain
than anticipated, temps will likely be in the low to mid 80s west of
I 65, and upper 70s looks ok across the nrn Bluegrass up to
Henry/Trimble Counties and over to Jefferson Co IN.

Lows will feel fall like Wed night (low to mid 50s (likely some 45-
50 F in low lying areas).

From Thu Day shift AFD which we agree with wholeheartedly...
"Afternoon rain chances should decrease below mentionable levels by
Wednesday, and locations which don`t receive rainfall Monday-Tuesday
(most of the area) will experience emerging/worsening drought

Weather History...

June 3 1921...A storm near Pikes Peak sent a high wave of water down
the Arkansas River into Pueblo, CO.  At least 70 people were killed
and $20 million dollars of damage was done to PUB.

June 4 1980...Edwin Robinson from Falmouth Maine had been blind and
partially deaf since a truck accident in 1971.  After being struck
by lightning on this date, his hearing and sight returned. Look
it up if you are skeptical, its a true story!


.Aviation...(06Z TAF Issuance)
Issued at 134 AM EDT Fri Jun 2 2023

Surface high pressure northeast of the region is causing drier air
to funnel into the Lower Ohio Valley. This will bring an end to
precipitation chances through the period, but for the rest of the
night, clear skies and radiative cooling are expected to cause
fogging at BWG due to the added moisture from earlier rainfall.
Winds will remain near calm overnight before northeasterly winds
increase to 5-10 knots during the day.




Short Term...KDW
Long Term...JDG
Aviation...KDW is the U.S. government's official web portal to all federal, state and local government web resources and services.