Area Forecast Discussion


972 
FXUS63 KPAH 160050
AFDPAH
Area Forecast Discussion
National Weather Service Paducah KY
650 PM CST Fri Dec 15 2017
.UPDATE...
Issued at 650 PM CST Fri Dec 15 2017
Updated aviation section for 00z TAF package.
&&
.SHORT TERM...(Tonight through Sunday night)
Issued at 221 PM CST Fri Dec 15 2017
Main concerns in the short term are elevated fire danger Saturday
followed by precipitation chances late Saturday night into Sunday.
The low clouds will continue to drift southward as they dissipate
and shift east of the area at some point this evening. This will
leave behind clear skies overnight with increasing southerly
winds. Temperatures will be tricky tonight. May see a quick drop
with clearing this evening and then some warming overnight through
sunrise. Did not get complicated with non-diurnal trends at this
time, and stayed close to the consensus of 12Z guidance for lows.
South winds will increase quickly Saturday morning, and 10-20 mph
sustained will be the rule in the afternoon. The mixed layer will
be rather shallow, which should cap the gusts at or below 30 mph.
Possibly due to the lesser mixing, the 12Z guidance has trended 
downward for highs on Saturday. Everyone should reach the lower to
middle 50s, but more of the area may only see the lower 50s. 
There will be some increase in surface dewpoints, which will keep
relative humidity levels mostly in the 35-45% range. The 
exception will be the Mark Twain Forest where readings may briefly
drop below 30%. This area will have the weakest winds which 
should mitigate any concern for a Red Flag Warning. We will
continue to mention elevated fire danger in the HWO, but do not
plan to issue any extra products for it.
A weakening mid/upper-level storm system will move quickly
northeast through the region late Saturday night and Sunday
morning. The models have definitely trended drier with this system
with QPF now under a quarter inch even along the southern border
of the area. We are still looking for stratiform rain, as the
models continue to develop a nice deep warm layer. Once the upper
system passes by midday Sunday, the moist layer will be confined
to the low-levels, which should preclude any measurable rainfall,
but some patchy drizzle cannot be ruled out Sunday afternoon and
night. 
As for temperatures, southerly winds will prevail throughout the
short term period, so we will remain at or above normal. Did not
stray much from the consensus of guidance.
.LONG TERM...(Monday through Friday)
Issued at 221 PM CST Fri Dec 15 2017
Strong confidence in the extended until day 6 into 7 when models 
diverge a great deal.
There will be an open wave move from the southwest and pass to our 
south. This will be accompanied by a front with not much in the way 
of cold air in its wake. It will also be very much moisture starved. 
So cant rule out a sprinkle or light rain but mostly a non event 
other than breezy and cloud cover. The biggest story will be the 
above normal temperatures next week with temperatures in the middle 
an upper 50s widespread...and with the aid of sunshine could even 
see some 60s in some locations. Confidence in the storm system 
Thursday night into Friday is high with its arrival but temperatures 
and available moisture are very much in question. The deterministic 
models vary greatly...approaching ten degree differences. This could 
result in very different precipitation types from all liquid to a 
mix. Models also vary greatly in moisture amounts from run to run 
even with the same models. Plan to hone in on Fridays solution with 
successive runs.
&&
.AVIATION...
Issued at 650 PM CST Fri Dec 15 2017
Clear skies expected through the TAF period at KCGI/KPAH, with
VFR cigs moving away from KEVV/KOWB by around 03z, with clear
skies through the rest of the period. Winds will be from southwest
around 5 kts overnight, increasing to around 10 kts with gusts
around 15 kts after 14z. No vsby restrictions.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...DRS 
LONG TERM...KH 
AVIATION...RST