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Area forecast discussion 
National Weather Service Grand Junction Colorado
259 am MDT Tuesday Mar 31 2015

Short term...(today through wednesday)
issued at 257 am MDT Tuesday Mar 31 2015

Warm conditions with gusty afternoon winds are expected again today
as a transient upper ridge slides east across the area. Winds today
should be a bit stronger and more widespread that yesterday...and
with low humidity could be a concern for any planned ag or ditch
Burns. Good solar heating will produce steep lapse rates and an
upper disturbance moving from SW Utah across NE Arizona today may kick off
isolated showers or thunderstorms this afternoon mainly over the San
Juan Mountains a dearth of low-level moisture works against much
measurable precipitation though...with gusty outflow winds the
bigger threat.

Wednesday looks like a windy day as a Pacific trough crossing the
northern rockies pushes a cold front into the north...and an upper jet
cuts across southern Utah to The Four Corners. The front should reach NE Utah
around 12z Wednesday morning and then stall across northwest or west-
central Colorado during the day. Upward forcing in the left exit region of
the jet overtop the stalled front should result in scattered
showers/thunderstorms over the central and northern Colorado mountains Wednesday
afternoon... with isolated showers/thunderstorms in the San Juans.
Moisture appears lacking though...as models do not maintain the
narrow subtropical moisture tap currently feeding into the pacnw
trough per satellite water vapor images. Low afternoon humidities
can be expected especially in the warmer air south of the front.
Behind the front...high temperatures across NE Utah and northwest Colorado will be about
10 degrees cooler than today.

Long term...(wednesday night through monday)
issued at 257 am MDT Tuesday Mar 31 2015

A surface cold front remains prognosticated to move across the region
Wednesday evening dropping temperatures and bringing some precipitation to the
area. Instability increases as does cape so do expect some
thunderstorms to rumble into Wednesday night. The same ole story
though with little moisture for anything to really work with so
precipitation will be on the low side with some gusty winds from storms the
biggest concern. An upper level trough then swings through
Thursday into Thursday night. Some isolated showers possible with
snow at higher elevations with this trough but again...low
moisture will limit precipitation amts. Furthermore...models are picking
up on some midlevel circulation on the Front Range allowing
better lift and more precipitation there. Aside from precipitation...winds will
pick up...mainly for southern half of the County Warning Area...as a strong jet moves
overhead especially for the San Juans. Freezing temperatures a
possibility once again Thursday but more so on Friday morning.

Some very isolated showers are possible Friday but with most
energy off to the west...these will be very few and far between.
By Friday evening...zonal flow sets up as disturbances bring
precipitation to our south and over the pacnw while we will see some
high clouds from time to time over the weekend as temperatures start
warming up. At this point...models have a hard time dealing with
trough affecting pacnw and whether it will drop down the Pacific coast
or affect Great Basin. Blended solution of schc probability of precipitation for higher
terrain north of I-70 appears reasonable at this time.

&&

Aviation...(for the 12z tafs through 12z Wednesday morning)
issued at 257 am MDT Tuesday Mar 31 2015

VFR continues for taf sites though isolated showers/storms remain
possible over the central and southern mountains after 20z this
afternoon. Confidence not high enough to include in any tafs
though. Expect wind gusts from showers and storms to reach 35 to
40 miles per hour. Surface winds of 10 to 20kts are also expected in the
afternoon with higher gusts at times.

&&

Gjt watches/warnings/advisories...
Colorado...none.
Utah...none.
&&

$$

Short term...jad
long term...tgr
aviation...tgr

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