NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

FXUS63 KJKL 081601 AFDJKL

AREA FORECAST DISCUSSION National Weather Service Jackson KY 1101 AM EST Fri Dec 8 2023

UPDATE
Issued at 1102 AM EST FRI DEC 8 2023

The current forecast is on track. Main changes were to refresh text wording for the forecasts.

UPDATE Issued at 630 AM EST FRI DEC 8 2023

The current forecast is on track this morning so have just added in the latest obs and trends for the T/Td/Sky grids. These updates have been sent to the NDFD and web servers.

SHORT TERM
(Today through Saturday)
Issued at 430 AM EST FRI DEC 8 2023

Key Messages:

* Another warm day under mostly sunny skies as highs will be in the upper 50s to lower 60s.
* Dry air and breezy conditions also affect the area this afternoon.
* Showers arrive late tonight with some thunder possible later Saturday afternoon.

09Z sfc analysis shows high pressure shifting off to the east of Kentucky as deep low pressure is approaching from the northwest.
This has set up a decent pressure gradient across the area supporting southwest winds of 5 to 10 mph with mild temperatures in the mid 40s on the ridges and in the more open areas. However, mainly thin high clouds and light to calm winds allowed the more sheltered valleys to radiate down into the upper 20s and lower 30s. This is amid dry dewpoints in the mid to upper 20s for most locations. The winds, high clouds, and lower dewpoints are keeping any fog at bay this night.

The models, and their individual ensemble suites, are still in excellent agreement aloft through the short term portion of the forecast. They all depict a low amplitude 5h ridge sliding east through the Southeast today in advance of a deepening, and soon to be full latitude, trough dropping into the Northern Plains.
The process will turn the mid level flow to the southwest and increasing in speed from this afternoon into the weekend.
Impactful energy impulses then spread into Kentucky by early Saturday as that trough starts to move into the region - eventually bringing a prolonged period of height falls to eastern Kentucky starting midday Saturday. Given the small spread among the model suites, again preferred the blended NBM as the starting point for the forecast grids, though with significant adjustments drier needed for the dewpoints and RH this afternoon.

Sensible weather will feature a warm and pleasant day with plenty of sunshine, but also dry and breezy conditions in the afternoon allowing for one more day of fire weather concerns before the weekend system sets in. Clouds, southwest breezes, and increased moisture will make for more uniform and mild temperatures through the night with only a small window in the evening for radiational cooling and extra valley cooling. Warm conditions then continue through the day, Saturday on breezy southwest winds. Look for an increasing threat of showers through the day with even enough instability around later in the afternoon/evening for a chance of some thunder. A better threat for thunder and localized heavy rain arrives later that night continuing into Sunday as the system's slow moving cold front eases through this part of the state.

The main adjustments to the NBM starting point were to go with more NBM 10 percent dewpoints this afternoon along with its 75 percent values for high temperatures. PoPs were ramped up later tonight from west to east with some extra detail provided by the CAMs consensus guidance into Saturday afternoon.

LONG TERM
(Saturday night through Thursday)
Issued at 510 AM EST FRI DEC 8 2023

Key Messages:

* Localized flooding is possible (5 percent chance of exceeding flash flood guidance) Saturday night into Sunday.
* Rain will mix with or fully transition to snow Sunday night, with light accumulations possible across the higher terrain.
* Dry conditions and a warming trend return Monday through Thursday.

The long term period begins with good agreement aloft among the global models. A large positively tilted trough will cover the heart of the CONUS with a stout closed ~532 dam upper low across northern Wisconsin and the western half of the Upper Peninsula of MI. A surface low will be situated across eastern Ontario with a long cold front stretched back toward the upper Great Lakes and cutting through the Ohio Valley, lower Mississippi Valley and southern Texas. Rain chances will increase as the cold front approaches the area during the latter half of the short term period but the bulk of the expected rainfall will fall Saturday night into Sunday. Instability will be meager but a few rumbles of embedded thunder cannot be ruled out Saturday night into Sunday morning. A LLj around 850mb will increase to between 40-50 knots Saturday night along with PWAT values increasing to between 1-1.25 inches. This will be a prime environment for efficient and steady rainfall. QPF totals range from 1.5-2.5 inches with the highest totals expected across the southwest and lower amounts farther northeast. WPC has placed all of eastern Kentucky in a marginal ERO (5% chance of exceeding flash flood guidance) for Saturday night (Day 2) and Sunday (Day 3). There are a couple factors leaning towards a favorable outcome despite the high QPF totals expected, one being the ongoing D2 drought across the southwest where the highest totals are expected and the longer duration of the event. However, the lack of vegetation this time of year will lead to more run-off and embedded convection could lead to higher rainfall rates which would contribute to localized flooding issues.

The cold front will reach the western portion of the CWA late Saturday night and will traverse all of eastern Kentucky by Sunday afternoon. Rain will continue into the evening before colder air begins to filter into the area behind the front. This will support a transition to a mix of rain and snow and possibly all snow for part of Sunday night. Totals at this time do not look impactful except for parts of the higher terrain which could see totals near an inch.
Totals outside of the higher terrain will range from a dusting up to two tenths in the more sheltered/coolest valleys and even so, this will likely be on elevated surface and grassy areas as roadways remain above freezing. Ensemble member (both GFS and ECMWF) support light to no accumulation for most locations with most members either producing no accumulation or a couple tenths with an outlier producing several inches for the JKL office which has skewed the mean to amounts near half an inch.

High pressure builds into the area on Monday and remains in place through the remainder of the long term period which will support dry conditions and a warming trend with temperatures approaching 50 by Wednesday and Thursday.

AVIATION
(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 650 AM EST FRI DEC 8 2023

VFR conditions will hold through the period with just some passing high and mid-level clouds, at times. light winds will continue from the south to southwest this morning while a low- level jet is exiting the Lower Ohio Valley still likely affecting the airspace over KSYM with some LLWS. Otherwise, sustained winds will trend towards 10 kts for most areas by 14Z, once the nocturnal inversion mixes out. Some gusts as high as 20 kts could occur, as well, generally between 14Z and 22Z. Winds will stay up at near 10 kts from the south southwest into the night while high VFR CIGs start to lower late and a few showers approach from the west.

JKL WATCHES/WARNINGS/ADVISORIES
NONE.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Knoxville/Tri Cities, TN,