273 
FXUS63 KLMK 151145
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
645 AM EST Sat Feb 15 2020

...Updated Aviation Discussion...

.Short Term...(Today and tonight)
Issued at 330 AM EST Sat Feb 15 2020

Conditions are clear and cold this morning with steady temps in the 
teens. An upper trough continues to move east over the northern 
Plains while a downstream ridge builds east across the eastern 
United States. At the surface, high pressure drifts east over the 
Mid-Atlantic. Temps have stabilized due to warmer air advecting 
in aloft via SW return flow. 

Southerly low-level flow will continue to increase during the day 
with a tightening pressure gradient between a Plains/Upper Midwest 
cold front and the East Coast high. The northern system, actually 
centered over Hudson Bay, will keep deep moisture well north of the 
region. A mainly clear start will allow temperatures to jump pretty 
quickly after sunrise. An increase in cirrus is expected this 
afternoon and evening. Afternoon highs are expected to range from 
the mid 40s north of I-64 to the lower 50s in southern KY. 

Mid-level clouds will thicken over southern IN and northern KY 
tonight. The clouds and south wind will result in a much warmer 
night with lows generally in the mid 30s.

.Long Term...(Sunday through Friday)
Issued at 325 AM EST Sat Feb 15 2020

By Sunday morning, a Canadian Low will continue advancing ENE across 
Hudson Bay with troughing extending southward across the central US. 
Most of the dynamics of this system will remain far to our north, 
but broad, weak lifting across the Ohio Valley, coincident with a 
moist SW flow below 850mb, may be enough to produce some light 
rain/sprinkles. Otherwise, expect a mostly cloudy end to the weekend 
with highs reaching into the upper 40s to lower 50s. 

A quick dose of dry air in the mid levels will shut off any rainfall 
late Sunday night before rain chances return Monday morning. Broad 
isentropic lift will see PoPs gradually increase from W to E across 
the CWA as increased moist air advects in from the Gulf of Mexico. A 
respectable 50KT LLJ will develop ahead of an approaching cold front 
overnight Monday into Tuesday morning that will likely see gusty SW 
winds in the 20-30mph range until FROPA occurs midday Tuesday. Zonal 
flow will allow for a rather progressive system that will keep QPF 
limited to under a half inch for most. Model soundings are showing 
convective potential for our southern counties, which may result in 
some slightly higher accumulations. Will keep an eye on this feature 
as new data becomes available. 

Modified cP air will move into the region behind the aforementioned 
front, which could result in some light snow as the mid and low 
level moisture departs the region. Little if any impacts are 
expected as the prior day's (Tuesday) max temperatures will have 
reached into the 50s. 

Wednesday afternoon through Saturday appear to be dry as upper level 
ridging and surface high pressure dominate the region. Morning lows 
will start off on the cool side from Thursday through Saturday with 
temps ranging in the 20s. Highs will rebound quickly though with 
Thursday in the 30s, Friday in the 40s, and Saturday trying to reach 
into the 50s.

&&

.Aviation...(12Z TAF Issuance)
Issued at 645 AM EST Sat Feb 15 2020

VFR conditions to continue through this TAF period. SCT cirrus will 
be the primary cloud cover today, though a 6 kft deck will slide 
east over areas near and north of the Ohio River this morning. A 
light southeast wind will increase to 10-15 kts by late morning and 
veer southerly in the process. Gusts to around 20 kts are expected 
this afternoon through 23z or so. Marginal LLWS conditions will then 
be in place once sfc winds diminish this evening. After 23z, a 35-40 
kt LLJ from the southwest will contribute to LLWS. Mid-level clouds 
will thicken with lowering ceilings late tonight in southern IN and 
northern KY.

&&

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

$$

Short Term...EBW
Long Term...CG
Aviation...EBW