515 
FXUS63 KJKL 122028
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
428 PM EDT Sat Apr 12 2025

.KEY MESSAGES...

- Our next in a series of cold fronts will approach Monday and
  move through Monday night, bringing at least a likelihood of
  rain for most places.

- Some thunderstorms Monday afternoon into Monday evening could be severe
  with damaging wind gusts the primary threat. 

- Temperature swings can be expected over the next week due to the
  quick moving nature of significant weather systems.

- On the coldest nights (mainly tonight and Tuesday night), frost
  will be possible.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 332 PM EDT SAT APR 12 2025

Surface high pressure is centered over the mid-Mississippi Valley 
this afternoon. This is keeping mostly clear skies across the area 
but northerly flow around the high is advecting moisture into the 
region from the Great Lakes thus favoring cumulus development this 
afternoon. Also, the northerly flow is keeping temperatures cooler 
as current temperatures are in the low to mid-50s.

Through the remainder of the day, the surface high will shift 
eastward and subsidence will allow for clearing skies for the 
overnight. The clearing skies and northerly flow will aid in falling 
temperatures overnight and development of frost. As a result of the 
frost possibility, a Frost Advisory was issued from 2 AM tonight 
through 9 AM Sunday. 

Locally, surface high pressure will remain in place; however, to the 
west, an upper-level trough and surface low with accompanying fronts 
will begin to lift toward the Great Lakes. The southwesterly flow 
from the trough will bring warmer temperatures to the area for 
Sunday but the associated warm front will dive southeast into the 
area. Increasing PoP chances (15-20%) are expected Sunday afternoon 
into Sunday evening for areas northeast of a line Flemingsburg to 
Harlan. Once the front lifts through the area, the CWA will be under 
the regime of weak high pressure under the warm sector and dry 
weather with warming temperatures are forecast for the remainder of 
the forecast period.

.LONG TERM...(Monday through Saturday)
Issued at 425 PM EDT SAT APR 12 2025

The period is expected to begin with upper level ridging 
extending from the Gulf coast to Southern Appalachians to middle 
OH Valley to eastern Great Lakes and additional upper level 
ridging extending across portions of the western Conus. In 
between, an upper level trough should be in place from Central 
Canada south into the Central Conus. Within this trough, an upper 
level low/shortwave trough is expected over the upper MS Valley 
vicinity and nearing the western Great Lakes. At the surface, high
pressure should be in place initially form the Atlantic into 
portions of the Southeast and Gulf as well as north to the Mid 
Atlantic states. Futher west and northwest, surface low pressure 
is expected to be in the vicinity of Lake Huron with a frontal 
zone trailing to the mid MS Valley to Southern Plains and then 
toward the Four Corners region. Behind that boundary, a ridge of 
sfc high pressure is anticipated to extend from sections of BC 
and Alberta southeast to portions of Plains and central Conus.

From Monday to Tuesday night, the axis of upper level ridging 
should shift to the eastern seaboard and off into the Atlantic.
Meanwhile, an upper level low will move from the upper MS Valley 
across the northern Great Lakes to the Quebec and Ontario border 
area, while the axis of the associated upper level trough moves 
to the MS Valley and then into the eastern Conus nearing the 
eastern seaboard by late Tuesday night. Locally, height rises are
anticipated The sfc low associated with the upper low and trough 
will track from the vicinity of Lake Huron and also to near the 
Quebec and Ontario border region. The trialing cold front will 
move across the Great Lakes Monday and Monday evening and into the
Northeast Monday night, while further south the front will drop 
southeast across the Lower OH Valley and Commonwealth working 
southeast of eastern KY by the overnight hours Monday night.
A colder airmass Surface high pressure will build toward the area
behind the front from the Central Conus though a few passing 
shortwaves may prolong cloud cover and shower chances at times, 
especially north and east into the Tuesday. The sfc ridge of high 
pressure continues to build toward the area on Tuesday night.
Below normal temperatures are anticipated for Tuesday through
Tuesday night and frost cannot be ruled in for some valley
locations, especially the more western locations.

As for thunderstorm chances Monday to Monday night, daytime 
heating on Monday should lead to steepening low level lapse rates,
especially further south and east into the CWA while dewpoints 
should be lower in that area. Mid level lapse rates are expected 
to be quite steep as well, generally 7 to 8C/km. MUCAPE is 
generally forecast to reach into the 500 to 1000 J/kg range across
eastern KY with bulk shear and perhaps effective shear of 40 to 
50KT or more. There remains some uncertainty as to how high sfc 
dewpoints will get and this would affect MLCAPE and overall CAPE 
and the CAPE and shear balance. At this point, strong to damaging 
wind gusts appear to be the primary threat.

Wednesday to Thursday night, locally some height rises are 
expected as the axis of an upper level ridge moves into the 
western Conus as upper troughing continues to depart further to 
the east and an upper level trough and low evolves over the 
western Conus and a shortwave trough nears the Dakotas. The 
surface ridge of high pressure is expected to continue to work 
across the area and depart to the east during this timeframe. 
However, at the same time, downstream of the troughing evolving to
the west and northwest, sfc low pressure will begin to evolve 
over sections of the Central Conus. A warm front may lift across 
the OH Valley on Thursday night as this begins to take shape. 
Overall, after the lingering cold airmass and some below normal 
temperatures especially for highs Wednesday and lows for Wednesday 
night with some chance for frost generally in more eastern 
valleys, temperatures moderate to near normal for Thursday. 
Convection cannot be ruled out as the warm front lifts through 
late, though better chances hold off until the end of the week.

Friday into Saturday, upper level ridging is progged to shift to
the east and southeast while troughing moves into the Central
Conus and then toward the Great Lakes to OH Valley. A sfc low
pressure system or series of waves should track to the west and 
northwest of the area during this period as well while the 
trailing cold front sags toward the OH Valley. Milder temperatures
are expected to the south of this boundary to above normal, while
increasing moisture and the boundary nearing the area long with 
one or more passing shortwaves will lead to a period of unsettled 
weather with periodic chances of convection.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 138 PM EDT SAT APR 12 2025

VFR conditions are prevailing across all TAF sites with this TAF
issuance. A cumulus deck around 5,000 ft has developed and will
persist through the afternoon before dissipating later tonight to
become SKC. Terminals KSME and KLOZ could see MVFR valley fog
developing tonight after 08Z before burning off after 12Z to
become VFR. Light north to northeast winds will exist through the
afternoon before becoming light and variable overnight. 

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 2 AM to 9 AM EDT Sunday for KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.

&&

$$

SHORT TERM...VORST
LONG TERM...JP
AVIATION...VORST