Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 241102
Area Forecast Discussion
National Weather Service Louisville KY
602 AM EST TUE NOV 24 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Wednesday)...
Issued at 249 AM EST Tue Nov 24 2015
High pressure moving up the eastern seaboard will keep us dry with
cirrus as the main cloud type and slowly moderating temperatures
today through tomorrow. We can expect afternoon temperatures today
in the middle and upper 50s, with readings tomorrow 2-4 degrees
warmer. Lows tonight will mostly be in the lower and middle 30s.
.LONG TERM (Wednesday Night through Monday)...
Issued at 309 AM EST Tue Nov 24 2015
Wednesday and Thanksgiving Day still look good for local travel and
other holiday activities. Temperatures will continue to moderate as
we sit between high pressure to our east and an advancing cold front
coming in from the west. Lows Wednesday night will range from the
mid 30s in the eastern Blue Grass to the mid 40s west of I-65.
Turkey Day will be pleasant with highs in the lower and middle 60s
under partly sunny skies (more cloud north of the Ohio, less cloud
toward Lake Cumberland).
A plume of moisture streaming up from the Gulf into the Plains on
Thursday will shift eastward in concert with the aforementioned cold
front. Widespread showers can be expected Friday and Friday night as
the front moves through the region.
The models have been struggling with what will happen this weekend
and into next week as they attempt to get a handle on the evolution
of a western trough as it ejects from the Rockies toward the Great
Lakes. GEFS plumes showing a large spread during this time and
forecast uncertainty graphics indicate below normal confidence in
the OH and TN valleys. 12Z/23 ECMWF ensemble showing a very large
spread in temps and, even moreso, PoPs Saturday through Monday.
Significantly, though, the operational run of the model is an
outlier, positioned well out on the tail of the ensemble members PoP
distribution. Whereas the 12Z/23 operational run was dry, the
consensus among the members is wetter. Add to this the 00Z/24
operational run of the ECMWF coming in wetter and much closer to the
GFS solution than previous runs were, and confidence increases a bit
for a wetter, rather than drier, weekend.
So, given all that, it appears for now that the Friday night cold
front will sink just to our south, and then return north as a warm
front over the course of the weekend, possibly being to our north by
Monday. Thus, we will keep chance PoPs in the forecast through the
weekend and into early next week. At this time of year there is
always some concern of mixed precip on the cool side of a lifting
warm front, and indeed earlier runs of the GFS showed a weak
freezing rain signal late Saturday night/early Sunday morning
primarily over southern Indiana. However as of this writing the
models have trended a bit warmer for that time period and we are
continuing to advertise Sunday morning lows above freezing. So,
nothing to worry about at this point, but something we`ll watch over
the coming days.
.AVIATION (12Z TAF Update)...
Updated at 602 AM EST Tue Nov 24 2015
Sfc high pressure and weak upper level ridging will dominate this
TAF cycle, with VFR conditions. Expect light south winds through
today, then backing to a SE component this evening. A few upper
clouds move over the region today and tonight.