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Area forecast discussion
National Weather Service Grand Junction Colorado
355 am MDT Mon Aug 19 2019

Short term...(today through tuesday)
issued at 355 am MDT Mon Aug 19 2019

Dry and hot conditions are expected once again today as we will
remain under the influence of high pressure and a dry southwest
flow. Winds will be much less today than yesterday and previous
days as the upper level jet lifts north of the region into
Wyoming. Some breezy conditions will occur this afternoon at times
with Moffat County in northwest Colorado closer to the Wyoming
border seeing the best chance for more elevated winds. However,
spatial coverage and duration of winds to 25 mph or greater
appears limited, so decided not to issue a red flag warning at
this time.

The gradient relaxes even more on Tuesday with dry and hot
conditions continuing under a lighter southwest flow. Precipitable
water (pw) values remain below 0.5 inches for much of the area.
Moisture will be increasing over the Front Range and eastern
foothills, with areas along the Continental Divide potentially
seeing a bump up to 0.6 inches of precipitable water. There is a slight chance for
an isolated storm or two over the eastern San Juans but confidence
in this occurring is very low due to the presence of very dry air
on the West Slope and lack of forcing. Temperatures look to push
record highs as we approach the middle of the work week.

Long term...(tuesday night through sunday)
issued at 355 am MDT Mon Aug 19 2019

Moisture slowly increases Wednesday through Friday along the
Continental Divide with deeper moisture over the Front Range and
plains. Our County Warning Area will be on the far western fringe of this moisture
advection with precipitable water values creeping towards 0.75 inches along the
Continental Divide. This happens as a low pressure trough pushes
into the Pacific northwest and shifts the high a bit eastward.
Much of the western slope remains dry though with precipitable water values less
than 0.5 inches, with exception of the western Colorado mountains
and Divide. What this all means is isolated to scattered storms
will occur each afternoon from Wednesday through Friday over the
mountains along the Continental Divide in western Colorado, while
the rest of the forecast area remains mostly to partly sunny and
hot. Storms in this drier environment will be capable of producing
more wind than rain, so don't get your hopes too high if you are
expecting cooler, wetter weather and an end to this dry heat.

Lower valleys of east-central and southeast Utah as well as west-
central Colorado will be approaching or reaching triple digits on
Wednesday before the Pacific northwest trough moves across the northern
rockies Thursday and Friday, dragging a couple shortwaves through
the area. These shortwaves Thursday and Friday will act to bring
in drier and slightly cooler air in from the west and push the
moisture further east. By cooler though, I mean instead of near
triple digit heat in the Lower Desert valleys, it will be more in
the mid to upper 90s. Still, the record high for Grand Junction on
Wednesday is 97, so with a forecast high of 99 (near 100), we have
a good chance to break this record. Not much reprieve from this
heat is expected as high pressure builds back to the west by the
weekend into early next week with continued hot and dry


Aviation...(for the 06z tafs through 06z Monday night)
issued at 1121 PM MDT sun Aug 18 2019

VFR conditions are expected through Monday with mostly clear
skies. Breezy gusts are expected at all taf sites by 18z before
diminishing during the evening hours.


Fire weather...
issued at 355 am MDT Mon Aug 19 2019

Dry, hot and breezy conditions will occur this afternoon. Winds
will be much less today than previous days. Conditions look to
approach critical fire weather conditions across Moffat County in
northwest Colorado at times due to the closer proximity to the
upper level jet across Wyoming. However, the areal coverage looks
less than 50 percent and it may hit for an hour or two here and
there. Due to limited areal extent and duration less than the
required three hours, decided to hold off on issuing a red flag
warning for Colorado fire zone 200 at this time. Other areas look
to see gusts to 20 mph at best with localized gusts up to 25 mph
at times, staying below red flag criteria. The gradient relaxes
even more on Tuesday with less wind, however, conditions will
still remain dry and hot.


Gjt watches/warnings/advisories...


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