Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 260939
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
339 AM MDT THU MAY 26 2016

.SHORT TERM...(Today through Friday)
Issued at 313 AM MDT Thu May 26 2016

An area of low pressure, currently over central Arizona, will
continue moving eastward this morning. As this occurs, specific
humidities will also slowly start increasing indicating an
increase in available moisture. QG forcing will also be on the
uptick as both the NAM and GFS show plenty of omega, or vertical
motion, moving in to the forecast area by daybreak. This is to be
expected as the center of low pressure moves across eastern Utah
and western Colorado. This center of low pressure will also advect
cooler mid level temps increasing instability which is borne out
by fairly high lapse rates.  With all these ingredients in place,
we can expect an increase in showers and thunderstorms across the
region. Examination of cross sections and sounding data does
indicate a fairly dry boundary layer which will keep showers and
storms relatively high based. One minor concern is coverage as the
HRRR and RAP13, very short range models, are nowhere near as
aggressive as the NAM/GFS/EC. Will be something to keep an eye on
as the day progresses and convection begins. A few inches of snow
still remain possible but only at the highest elevations of the
San Juans this afternoon. No highlights necessary in that regard.

Convection should start an hour or two before noon and continue
as the day moves forward. The Continental Divide and San Juans
look favored though all higher terrain will likely see some
convective development. While H7 winds are light, a few cells will
drift into valleys.

Plenty of clouds and precip will keep temps below normal as has
been the case for many days this month.

By Friday morning, the low pressure center will have shifted to
eastern Colorado and even through a short wave ridge builds in,
plenty of moisture beneath said ridge and heating will destabilize
the atmosphere to fire off some showers and storms. Coverage is
expected to be less than that seen on Thursday.

.LONG TERM...(Friday Night through Wednesday)
Issued at 342 PM MDT Wed May 25 2016

Residual moisture will fuel scattered to numerous showers and
thunderstorms during the afternoon/evening through much of the
long term period. In fact, this trend plays out during the
weekend and into the first half of the coming week as mean
troughing persists over the western U.S. Temperatures will recover
to near normal Saturday and will remain at, or a little above,
normal through early next week.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 313 AM MDT Thu May 26 2016

VFR conditions will continue through midmorning though clouds will
be on the increase especially down south. A few isolated showers
are possible this morning, generally over the San Juans, but will
be very spotty. Between 16Z and 18Z, isold to sct TSRA will start
forming over higher terrain. KASE and KTEX look to be the airports
that have the highest chances for -TSRA on station though they
should remain above ILS breakpoints. If they do drop below those
breakpoints, it should be for a short period. Remaining Colorado
TAF sites will also be under the gun for some convection though
not as confident at these sites. Expect some gusty winds
underneath the stronger showers and storms.

&&

.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&

$$

SHORT TERM...TGR
LONG TERM...NL
AVIATION...TGR


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