Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 250843
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
243 AM CST Thu Dec 25 2014
.SHORT TERM...(Today through Saturday night)
Issued at 233 AM CST THU DEC 25 2014
Low clouds are making steady eastward progress, and should
continue and allow for a return of sunshine this Christmas day.
Heights rebound as well, and with southerlies kicking in, it will
be a mild Christmas day as well, with tempeatures warming toward
the 50 degree mark.
Broad surface high pressure anchors across the Southeast Friday,
and the return flow around it draws Gulf moisture up the
Mississippi river valley. By Friday night, the result will be
a return of Pops to the forecast for us. The blayer will be warm
enough, with temps in the 40s even at night.
Pops expand/increase Saturday as a cold front approaches and makes
passage. As it does, low pressure develops along the southern end
of the boundary, on the Gulf coast, and lifts northeast across the
Tn valley Saturday night. This will help overrunning moisture
continue rain chances (post frontal) into Saturday night, esp
across our southeastern counties. Even so, blayer temps are still
plenty warm enough for entirely liquid pcpn. And marginal blayer
temps in our farthest northern/western counties encounter
insufficient moisture there, to support any Pops/chance of frozen
.LONG TERM...(Saturday through Wednesday)
Issued at 240 PM CST WED DEC 24 2014
First with respect to the models. The 12z ECMWF has trended closer
to the 12z GFS. The overall depiction, of a digging trof over the
west U.S. into the inter-mountain west is what is closest to a number
of prior runs over the last 3 days or so. There have been outlier
runs, such as the 00z ECMWF, farther east with the initial digging
trof out west, along with some CMC runs. Given those are in the
minority, went with a 12z ECMWF/GFS blend. The ensemble mean
solutions may have smoothed out some details. But overall they would
tend toward even those outlier solutions. So the blend lies with the
most consistent pattern depiction maintained in the 12z runs.
What this means for the forecast is, a notable reduction in PoPs
beginning Sunday, with mainly a dry forecast now in place Monday
through Wednesday night.
First, Saturday, went above blend output and introduced likely PoPs
everywhere for showers, given the strong EC/NAM/GFS agreement. Cold
front still forecast to move through, supported by low trop WAA and
H7 forcing. QPF not terribly high, but most areas should get some
rain shower activity. Best PoPs will gradually shift east Saturday
The s/wv forecast to eject NE out of TX Sunday really dampens out on
the 12z ECMWF. Prior runs were a bit too robust with this feature.
The ensemble means and GFS runs seemed to depict the weakening
better. This should result in best moisture being shunted with time
to our SE, as drying works in from the WSW. We do maintain a slight
chance of light precipitation Tuesday night, maybe light freezing
rain/light snow. Went with only slight chance PoPs given limited
Arctic air will gradually arrive by the middle of the week. Temps
were initially a blend of direct model output and MOS, then more of
a MOS/Ensemble MOS and blended model approach toward the end of the
long term period.
Issued at 233 AM CST THU DEC 25 2014
We see the low clouds starting to disperse in the Missouri Ozarks,
and a good west to east movement on the 11-3.9u satellite loop.
Tracking the clearing line on the latest feed suggests a west to
east scattering of cigs this morning, resulting in clear skies/VFR
conditions for all terminals from this afternoon thru the
remainder of the forecast.