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Area forecast discussion 
National Weather Service Paducah Kentucky
143 am CDT Tuesday Apr 21 2015

Short term...(today through Thursday night)
issued at 134 am CDT Tuesday Apr 21 2015

A passing wave in the mean broad cyclone's trough will allow
frontogenetic forcing/associated probability of precipitation to redevelop and spread
along the lower Ohio River valley later today-tonight. The
wave/boundary makes passage by tmrw...so probability of precipitation will end west to
east as high pressure builds across the middle and upper
Mississippi Valley at the surface. Some dirty overrun of the high
from the south may warrant a small chance pop reappearance there
Wednesday night...otherwise we'll close out the short term mainly
dry/under the influence of the high. Upper level nwlys keep the
coolish airmass reinforced with 60s/40s staying the rule...but it
is possible that our farthest northern counties may see upper
30s/upper 50s on the coldest day/after the system passage...ie
Wednesday.

Long term...(thursday through monday)
issued at 235 PM CDT Monday Apr 20 2015

The dominant features in the long term...one deep vortex over
southeast Canada that will gradually move east...and another
settling into the Gulf of Alaska region. Weaker systems will
affect the lower 48. The first one of interest...should be a middle
level trough/low moving from the SW U.S. Into the Central Plains
from 00z Friday to 00z Sat...turning east-southeast and weakening across our
region Saturday. After that...the focus is on another wave moving
east-southeast from the plains late Sunday and across our area Monday.

The operational models continue to exhibit run to run consistency
issues. This is likely due to the weaker flow regime across the
Continental U.S. Below the two significant vortices. This means we will
parallel wpc's idea of blending the ensemble mean solutions for
handling the timing of the aforementioned features...and resultant
higher pop periods. We removed probability of precipitation Thursday and Thursday night.
Adjusted probability of precipitation Friday moving in from the west...and peaked probability of precipitation
Friday night with the wave coming in from the plains and affecting
the region. Should see probability of precipitation tail off by Saturday night as the
upper wave heads east-southeast away from the area. Lull Sunday...then slight
chance probability of precipitation Sunday night through Monday night. Will maintain a
limited thunder chance Friday through Saturday. Maximum and min temperatures
were a blend of MOS and existing numbers. Model preference was a
ensemble mean blend of the GFS/ec/naefs.

&&

Aviation...
issued at 134 am CDT Tuesday Apr 21 2015

Middle clouds will increase today and ceilings will develop and lower
with time. Southwest winds will gust over 20kts in association
with a middle level wave. Probability of precipitation attendant to the wave will show up on
the back end of the forecast as it makes passage and winds
eventually shift to the northwest.

&&

Pah watches/warnings/advisories...
Illinois...none.
MO...none.
In...none.
Kentucky...none.
&&

$$

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