000
FXUS63 KPAH 290529 AAB
AFDPAH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PADUCAH KY
1129 PM CST Wed Jan 28 2015

.UPDATE...
Issued at 1129 PM CST WED JAN 28 2015

Updated the aviation discussion for the 06Z TAF issuance.

&&

.SHORT TERM...(Tonight through Friday night)
Issued at 254 PM CST WED JAN 28 2015

Clouds will increase across the PAH forecast area tonight with the
approach of a cold front. Models are in very good agreement on the
track of the surface low, bringing it from southeast Iowa at 06z
Thursday to southern lower Michigan by 18z Thursday, which is also
the time frame for the frontal passage across our region. ECMWF
is the "wettest" of the models, and it only brings the hundredth
line into southern Illinois by 12z, then both GFS and ECMWF bring
the hundredth line east of the Mississippi through 18z, quickly
moving east after 18z. NAM keeps us dry altogether. Continued with
some low precip chances across our northeast counties for light
showers late tonight, then low chances across our counties east of
the Mississippi River Thursday morning. Kept some slight chance
pops across our far eastern counties early Thursday afternoon, but
even that may be too much. Overall no significant precip is
expected with the frontal passage. However, behind the front we
will see a pretty good cool down. It will also be a bit breezy
along and behind the front Thursday, gradually tapering off
Thursday night.

It will be quite mild tonight into Thursday, with lows tonight in
the upper 30s to lower 40s, which is close to what our normal
highs should be. On Thursday, highs will be in the middle 40s north
to lower 50s south. High pressure will slide across the upper and
middle Mississippi valley Thursday night into Friday, keeping our
region in northerly flow.  Friday highs will only be in the middle
30s to around 40 degrees Friday. Low temperatures Thursday night
and Friday night will be near seasonal in the 20s.

.LONG TERM...(Saturday through Wednesday)
Issued at 254 PM CST WED JAN 28 2015

Still having lots of fun with the storm system to impact the region
late Saturday through Sunday night. The medium range models continue
to disagree even on the basic pattern/timing, let alone the
temperature profiles and precipitation type. We will have to
continue to watch the model evolution through the end of the week to
hopefully get a more concise model signal.

The 12Z ECMWF has swapped over much closer to the GFS solution, with
even more and quicker impact of a significant surface high.
Unfortunately, it continues to be warmer in the low-levels than the
GFS, which gives cause to hold back on a snow forecast. The 12Z GEM
is offering a totally different solution than we`ve seen in the last
few days.

The 12Z GEM really develops a storm system over the northern Plains
and upper Midwest, as energy diving out of Canada interacts with a
low-level baroclinic zone. Given that there should be a decent
baroclinic zone and energy is dropping into a mean trough, the GEM
is quite plausible. It would result in a slower progression through
the area, and rain early, with better snow possibilities Sunday
night into Monday.

It is too early to attempt to latch onto one solution or another.
This forecast will trend a bit cooler, with an increased snow
probability. Given the thermal structure of the ECMWF and GFS, the
precipitation will be falling as snow and melting in the lowest
levels, so the rain/snow line will be highly dependent on the near
surface temperatures. Therefore, there are some minor snow
accumulations across the north late Saturday night and early Sunday
morning, and again throughout the area Sunday night, as the real
cold air surges across the area. Some potential still exists for an
inch or two of snowfall, mainly across the northern half of the
area.

Cold surface high pressure will dominate the region Monday and
Tuesday. South winds will return on Wednesday, and temperatures will
begin to modify. It appears that any significant precipitation
Wednesday will be stuck over the Gulf States as the remnants of the
southwest U.S. upper low push east into the northern Gulf.

&&

.AVIATION...
Issued at 1129 PM CST WED JAN 28 2015

Cloudiness will continue to increase and lower with the approach
and passage of a frontal system. VFR cigs prior to the frontal
passage are expected to become MVFR in its wake. Toward the end of
the period cigs may become VFR again at KCGI/KPAH. Southerly winds
10-15 knots will veer around to the northwest at 12-15 knots
gusting to 22-25 knots with the frontal passage starting around
14Z.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$

SHORT TERM...RST
LONG TERM...DRS
AVIATION...JP