grand junction co: fxus65 kgjt 081638 aaa

expires:no;;652081
fxus65 kgjt 081638 aaa
afdgjt
area forecast discussion
national weather service grand junction co
938 am mst mon feb 8 2010
.update...
snow continues to diminish in coverage and intensity this morning
and have dropped all winter highlights. have also dropped the
dense fog advisories as vsbys continue to improve and ceilings
lift.

.short term...today through tuesday night...
upper low over northern nm early this morning with the deformation
across the far s. light snow still observed across much of sw co
per sfc metar reports at 10z so will keep the winter highlights
intact south of interstate 70 though not too much additional snow
accumulation is expected. exception could be in the uncompaghre gorge
along highway 550 south of ouray where moist northerly flow is
favorable for locally heavier snow. will be canceling the winter
advisories for the eastern tavaputs/roan plateau/bookcliffs as
precip essentially ended there behind the deformation zone. dense fog
advisory continues for the grand valley and grand flat areas. areas
of fog also for the remainder of the i-70 corridor as well as se
ut/sw co where past rain and snow have nearly saturated the air near
the surface.
models in agreement on sliding the new mexico upper low east into the
srn plains and weakening by this evening...with an associated
decrease in snow from nw to se. 700 mb cold advection commences
across ne ut/nw co this afternoon as a trough moves from the dakotas
southward. this could keep some low clouds present there and also
hinder any warm-up in the north today. transient ridging tonight and
tuesday as the next pacific trough drops southeast into ca...
eventually closing off an upper low over srn ca tue night. moisture
again spreads into the region from the sw later tue for a chance of
snow in the mtns and srn valleys tue night.
.long term...wednesday through sunday night...
at start of long term...closed low will be located ovr ca/mex border
with pre-frontal trof affecting srn areas of co/ut. nam12 paints
meager qpf amts while gfs is more widespread. that being
said...low level flow appears too weak to create much of an upslope
component to aid orographic snow. a few inches possible ovr/near san
juans...with locally higher amts possible. precip will have ended by
thur morning as all dynamics will be well to our s.
for thur thru fri night...split flow sets up as anticyclonic flow
causes mean wind to become nwly as weak ridging moves in. again...
weak orographics will kick off showery type activity along
continental divide but no appreciable accumulation expected at this
time.
next system will move into area early sat morning as meager upper
level support closes off area of low pressure and causes precip ovr
much of co/ut. most substantial amts...once again...appear to be
san juans and areas s. interesting scenario though as models
depict low moving in from w and once reaching 4 corners...moves due
s. appears not enough support to overcome ridging to the w so path
of least resistance is swrd. ecmwf somewhat different soln as open
wave moves ovr area...but still drops it south. much less precip
with ecmwf too. thus...kept schc pops for most of long-term as
sporadic snow showers are expected...especially ovr mtns.
mos guidance showing a warm up in store by weeks end and corroborated
somewhat by gfs 5-wave. zonal flow becomes meridional as relatively
strong ridge with axis ovr ut/co border sets up allowing warmer
temps to advect in. forecast soundings not showing much in the way
of inversions either so guidance might finally be getting back on
track.

.aviation...
patchy fog and a few snow showers will briefly drop cigs and vsbys
into ifr thresholds through this afternoon. otherwise...vfr conds
will return to western colorado and eastern utah for the remainder of
the day. anticipate fog will be a concern again later tonight with
clearing skies...light winds and sufficient low level moisture.

.gjt watches/warnings/advisories...
co...none.
ut...none.


update.......jdc
short term...jad
long term....tgr
aviation.....tgr/jdc

Top tags: kgjx, snow, low, ovr, term, flow, fog, night, area, areas