Area Forecast Discussion
Issued by NWS Paducah, KY

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000
FXUS63 KPAH 260814
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
314 AM CDT Tue Aug 26 2014

.SHORT TERM...(Today through Thursday)
Issued at 313 AM CDT TUE AUG 26 2014

The 00Z models are in reasonably good agreement through the short
term period. The east to west oriented upper ridge will hold
strong over the region today, and hang on into Wednesday before
finally being suppressed to the south/southeast of the area Thursday.
At the surface, weak surface high pressure will dominate today,
but a back-door cold front will reach the I-64 corridor by the end
of the day Wednesday. This boundary will hang up somewhere across
southern Illinois and west Kentucky Wednesday night and Thursday.

The models and their statistical guidance continue to lower
dewpoints a bit each day, but they are keeping high temperatures
steady in the lower to middle 90s each day. A look at NAM and GFS
soundings revealed that the models do not have a good handle on
the moist dewpoints across the area.

Most areas will likely reach triple digit heat indices again this
afternoon. Much of the Pennyrile rebounded to around 100 Monday
afternoon, and figure today will be similar to yesterday.
Therefore, will let the Heat Advisory continue into its 7th
consecutive day.

The big question is whether or not it should be extended into
Wednesday. Forecast heat indices climb close to 100 over most of
the area again on Wednesday, as the trend in the forecast over the
last few days has been for higher heat indices on Wednesday. Would
prefer to see what happens today, and let the day shift make the
decision to extend or not.

The GFS and NAM try to extend the low-level thermal ridge eastward
across the southern half of the area Thursday. Dewpoints actually
mix down into the 60s in association with this thermal ridge.
However, with a frontal boundary in the region, would not be
surprised to see moisture pooling along it. Would not be at all
surprised to see at least the south or southwest half of the area
reach triple digit heat indices again Thursday afternoon. Will
have to make a decision on Wednesday before concerning ourselves
with Thursday`s prospects, but it is certainly within the range of
possibilities.

Convective trends for today are not well defined. Looks like some
widely scattered diurnally-forced development will be possible in
the Ozarks, and possibly along the Tennessee border. Will maintain
the small chances in the north Wednesday as the weak cold front
makes its approach. The models are not as wet with this surface
feature heading into Thursday, but small chances seem warranted
over much of the area.

.LONG TERM...(Thursday Night through Monday)
Issued at 313 AM CDT TUE AUG 26 2014

A return to dry weather is anticipated Thursday night and Friday as
high pressure ridging prevails aloft. One more day of temperatures
above the 90 degree mark is expected on Friday. However, with
relatively drier dew points in the mid 60s, peak afternoon heat
index readings should manage no higher than the mid 90s.

Forecast models are generally in good agreement in forecasting the
eastward progression of an upper level trough from the central
Plains into the Middle Mississippi and Lower Ohio Valleys over the
weekend. Increasing lift and moisture with this feature will
heighten the potential for showers and thunderstorms as early as
Friday night or Saturday. The greatest chance of convective activity
will most likely occur Saturday night and Sunday with the best
dynamics in place. While a few strong storms certainly cannot be
ruled out during this time, the main concern will be locally heavy
rain with deep unidirectional southwest flow and precipitable water
values in the vicinity of 2 inches.

The presence of clouds and precipitation will likely keep a lid on
daytime temperatures, thus highs in the 80s are forecast over the
weekend. It will likely be rather humid with lows each morning in
the upper 60s to lower 70s. Precipitation chances will decrease
early next week, but slight chances remain Sunday night into Monday.
Temperatures by Monday will be within striking distance of the 90
degree mark once again.

&&

.AVIATION...
Issued at 1107 PM CDT MON AUG 25 2014

Clear and calm conditions in place, which may lead to the anticipated
fog formation overnight at the Terminals. Only made tweaks to the
existing forecast. Some CU expected tomorrow with light ENE winds.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY until 7 PM CDT this evening FOR ILZ075>078-080>094.

MO...HEAT ADVISORY until 7 PM CDT this evening FOR MOZ076-086-087-100-
     107>112-114.

IN...HEAT ADVISORY until 7 PM CDT this evening FOR INZ081-082-085>088.

KY...HEAT ADVISORY until 7 PM CDT this evening FOR KYZ001>022.

&&

$$

SHORT TERM...DRS
LONG TERM...RJP





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