Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 031736

Area Forecast Discussion
National Weather Service Paducah KY
1236 PM CDT TUE MAY 3 2016

.SHORT TERM...(Today through Thursday night)
Issued at 242 AM CDT Tue May 3 2016

Above average confidence in the short term due to decent model

At the beginning of the short term period a closed H5 low was
centered just north of the Great Lakes region. A short wave rotating
around the southwest flank of the low will drop southward across the
lower Ohio valley this afternoon. Due to limited deep layer moisture
QPF should be sparse and limited to the northeast sections of our

After a brief respite this evening and most of the overnight hours,
the aforementioned upper low is forecast to drop southward along the
IN/OH border on Wednesday. The leading edge of precipitation
associated with it is forecast to make it into the far northern
sections of our CWA by 12Z (7AM), then spread southward across the
eastern half of our CWA by midday, then begin to diminish from west
to east in the afternoon in the wake of the low. There should be
enough surface based instability Wednesday afternoon over the far
eastern sections to warrant the mention of thunder.

Beyond that rising heights aloft and high pressure at the surface
should keep the region dry with slowly moderating temperatures
through the end of the period. However, temperatures will average
near to just below normal through the short term period.

.LONG TERM...(Friday through Monday)
Issued at 242 AM CDT Tue May 3 2016

Fairly good agreement among forecast models through early next week
is counterbalanced by a blocking pattern that starts the long term
and reduces confidence in how the overall pattern evolves over the

Starting with Friday, an omega block type upper level pattern should
be in place, with a highly amplified ridge over the central U.S.
flanked by two cut-off lows on both the Pacific and Atlantic coasts.
This pattern is expected to remain in place through at least the
first half of the weekend. The end result will be dry weather with
seasonably warm temperatures.

As early as Saturday night and Sunday, forecast models begin to
break down the omega blocking pattern as the formation of a deep
upper level low over southeastern Canada kicks the Atlantic low to
the east and suppresses the upper level ridge over the Heartland.
Energy from the Pacific low begins to stream eastward across the
Plains as a weak cold front drops southward into the Middle
Mississippi and Lower Ohio Valleys.

This initially results in a chance for showers and thunderstorms
along the Interstate 64 corridor during the latter half of the
weekend. The chance shifts south and east to encompass the entire
forecast area by Monday and Monday night. Later forecasts will
likely need some adjustment as they shed more light on how quickly
the pattern evolves.

Used a blend of model guidance for temperatures through the period.
Readings will generally be near or just above seasonal norms. Highs
are forecast to warm from the mid 70s on Friday into the upper 70s
and lower 80s over the weekend. Lows should moderate from the mid
50s Friday night into the upper 50s and lower 60s over the


Issued at 1235 PM CDT Tue May 3 2016

Main challenges with the 18z Tuesday WFO PAH TAFs were duration of
diurnal cold air stratocumulus and the onset and coverage of
showers/thunderstorms and attendant ceilings on Wednesday.
With the transition of ceiling heights over a 1-2kft layer,
selected a mean ceiling height that represented the longest
duration within a time period.


.PAH Watches/Warnings/Advisories...


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