Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 291816

116 PM CDT Tue Jul 29 2014

.SHORT TERM...(Tonight through Thursday night)
Issued at 104 PM CDT TUE JUL 29 2014

The short term forecast remains largely unchanged, with the same
basic synoptics and only minor/subtle massaging/tweeking
necessary. Cu field today is less expansive/dense than yesterday,
given the lower rh in the lower trop.

Mos suggests patchy fog developing tonight, which is possible. But
it looks like some upstream mid-high cloud could advect in around
the same time frame, thus limiting its expanse.

Tmrw we see 700-500 mb lapse rates approaching 6C, but with low
layer flow having a tough time returning (surface high anchors
across FA and to the east), the lower trop will remain moisture
deficient and while we could not totally rule out an isolated
diurnally aided shower or storm, the PoPs remain
low enough to preclude from mention. This represents no
significant change from past few model runs/forecasts.

By Thursday, some more vigorous energy/moisture advection in the
southern stream promotes a slight uptick in the overall PoP, to at
least warrant a slgt chance mention during the diurnally aided
daytime hours. This will apply for all but the far eastern 1/3 of
the FA, where lingering surface high pressure should suppress the
parcel uvm field.

Daytime Highs should return to the lower 80s FA-wide beginning
tmrw. Lows will make a gradual move toward, and will eventually
achieve, the lower 60s by the end of the period.

.LONG TERM...(Thursday night through Monday)
Issued at 327 AM CDT TUE JUL 29 2014

The impressive, almost semi-permanent cold core low centered along
the common Ontario/Quebec Province border will remain the dominant
feature through the extended portion of this forecast package. With
only minor changes in thermal thicknesses expected, temperature will
remain noticeably below normal, with highs in the lower and middle

At the surface and aloft, the WFO PAH forecast area will be
entrenched in a cooler and drier northwest flow.

There appears to be a dominant channeled vorticity axis that will
run through the Dakotas, southeast through the Tennessee Valley
Friday through Saturday. This will enhance the baroclinic zone along
the gradient of the eastern Canadian Provinces closed low,
supporting decent isentropic lift into the area. Isolated to briefly
scattered upright convection will be a possibility over the WFO PAH
forecast area during this time. The "rain" faucet should close off
once the energy in the trough is congealed into a mean trough axis,
east of the WFO PAH forecast axis, leaving only below normal

The suite of medium range guidance seems to have a similar evolution
of systems in the extended, so utilized a blend of guidance for
sensible weather elements. As expected, the CIPS Analog Threat
guidance for the aforementioned period suggests a minimum for severe
weather concerns. The main focus will be on temperatures during this
time frame.


Issued at 104 PM CDT TUE JUL 29 2014

Lower trop Temp/Td spread supports diurnally driven Cu field in
the 5-6K FT AGL range. Sky should clear of Cu with setting
sun/loss of fuel, though mid or high cloud blow off from upstream
makes an appearance by the planning period. Said appearance should
preclude MOS hints at vsby restrictions due to fog, although we
cannot rule it out.



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