Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

000
FXUS65 KGJT 260941
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
341 AM MDT MON SEP 26 2016

.SHORT TERM...(Tonight through Tuesday night)
Issued at 341 AM MDT Mon Sep 26 2016

Clear skies are being reported across the forecast area this
morning as high pressure continues to build over the Western
United States. Under these clear skies temperatures have fallen
into low to mid 30s over the high terrain and 40s to lower 50s at
many of the valley locations. WFO Grand Junction is currently
reporting a temperature of 51 degrees.

The 0000Z NAM12, GFS20 and ECMWF have initialized well with the
current synoptic weather pattern and remain in good agreement
through Tuesday night. The models build the 500MB ridge of high
pressure to 588DM over Eastern Utah and Colorado today with 700MB
temperatures reaching 71 degrees over Grand Junction. This
translates into an afternoon high temperature of 77 degrees at
Grand Junction, which is 7 degrees warmer than observed on
Sunday. On average temperatures around the forecast area will be 4
to 8 degrees warmer than those observed on Sunday. Another
pleasant day is expected on Tuesday with an additional 2 to 4
degrees of warming. High clouds are anticipated to increase
Tuesday evening as monsoon moisture begins to work its way back
into the area.

.LONG TERM...(Tuesday through Sunday)
Issued at 318 PM MDT Sun Sep 25 2016

Tuesday will bring one more day of sunny skies and warm
temperatures to the region as the area of low pressure slowly
moves northward. By Wednesday, some model differences begin to
arise. The NAM wants to keep the closed low closed while the GFS
opens up the low and replaces it with an open wave. The other
differences are that the NAM keeps the low and attendant moisture
further to our west and also speeds up the northward movement. The
GFS, on the other hand, takes the open wave and moves it directly
over our area bringing isolated precipitation Wednesday night
overspreading much of the CWA by daybreak. Quite the difference in
output so we`ll keep an eye on the next few model runs to see
which one wins out.

As far as precipitation is concerned, most rainfall looks to end
early Friday morning but by Friday afternoon another wave looks to
move over the region bringing another round of showers and storms.
By Saturday morning, the wave will have shifted well to our east
though some residual showers are possible favoring the higher
terrain. Snow levels look to be around 12,500 feet so only the
highest peaks should see any snowfall with little accumulation
expected.

Temperatures will run warm at the start of the long-term period
and drop to normal values as the system moves through.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday night) Issued at
341 AM MDT Mon Sep 26 2016

High pressure positioned over the Western United States will
provide clear skies over the terminals today. Expect typical
diurnal winds to be present through at least the next 24 hours.

&&

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

$$

SHORT TERM...Larry
LONG TERM...TGR
AVIATION...Larry



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.