Scientific Forecaster Discussion
Area forecast discussion...update
National Weather Service Pendleton or
1055 am PDT Sat Jul 12 2014
Updated for aviation discussion
Short term...update...the band of middle and high level cloudiness
ahead of a weakening upper wave continues to lift north through
southeastern Washington. This cloud band should exit our Washington
forecast zones by noon. As such should see plenty of sunshine today
and high temperatures will run between 95 and 104 at the lower elevations
and valleys. Generally this will be a slight warm up over yesterday,
except in central Oregon where cloud cover Friday substantially
suppressed temperatures. Warmest temperatures will be in the Washington Lower
Basin and this area should begin to meet the heat advisory criteria.
Other advised locations will probably be just below criteria today,
but should reach them tomorrow. Still expect there to be some
stabilization of the air mass today behind the departing upper wave.
Yet, still expect some isolated thunderstorms to develop over the
Cascades and some of the interior northwest mountains due to the
strong daytime heating. Updates this morning consisted of making
adjustments to thunderstorm areas, high temperatures and sky cover for
today and this evening. 90
Long term...previous discussion...on Monday...a trough will
continue to move through the region with an area of moisture and
instability. Best instability occurs Monday morning and by late day
much of it is pushed east into Idaho. The strong ridge rebuilds over
the region on Tuesday with continue hot temperatures. On
Wednesday...it appears that the ridge gets pushed south just a
little with more westerly flow across the Pacific northwest. The
models diverge on Thursday with the European model (ecmwf) keeping the region in a
west northwest flow while the GFS brings through another weak trough
in the northwest flow. Neither models has little in the way of
moisture but may they do lower The Heights over the area with
temperatures expected to cool a few degrees by Friday.
Aviation...18z tafs...VFR conditions are expected to prevail during
the next 24 hours. Few-scattered high clouds will clear out of the area
this morning...with middle level clouds forming this afternoon around
krdm...and kbdn. Thunder is possible at krdm...and kbdn...but
confidence is not high enough to mention...will amend tafs as needed
to include thunder. Winds are expected to be at or below 10 kts
during the entire taf period...with exception to krdm...which may
gust to 15kts this afternoon. Weber
Fire weather...on Sunday...subtropical moisture will move into the
region. This in combination with a weather disturbance will lead to
a chance of thunderstorms with abundant lightning over central
Oregon. With hot and dry conditions over the last several days and
the storms initially starting out with little rainfall...there is an
enhanced threat of new wildfires over central Oregon. Therefore... a
Fire Weather Watch has been issued for the central Oregon fire zones
Sunday and Sunday night.
Preliminary point temps/pops...
PDT 101 66 103 70 / 0 0 0 20
alw 101 71 104 75 / 0 0 0 10
psc 103 66 106 73 / 0 0 0 10
ykm 97 69 102 72 / 0 0 10 20
hri 102 66 105 71 / 0 0 0 20
eln 100 63 102 66 / 10 10 10 20
rdm 96 58 98 58 / 20 20 40 30
lgd 96 59 97 63 / 10 10 0 20
gcd 99 63 99 66 / 10 20 20 30
dls 101 70 104 71 / 10 10 20 30
or...Fire Weather Watch from Sunday morning through Sunday evening
Heat advisory until 9 PM PDT Tuesday orz041-044.
Washington...heat advisory until 9 PM PDT Tuesday waz024-027-028.
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