Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 220925

Area Forecast Discussion
National Weather Service Grand Junction CO
325 AM MDT Mon Oct 22 2018

.SHORT TERM...(Today through Tuesday)
Issued at 324 AM MDT Mon Oct 22 2018

Broad, cyclonic flow across the Great Basin will continue to send
moisture northward through Tuesday with scattered showers and
isolated thunderstorms becoming more common over the next 24
hours. Models picking up on a wave kicking out of the main trough
late this afternoon and evening that will provide the trigger to
get a more organized band of showers and storms driving northeast
overnight. Steep mid-level lapse rates, improved shear form
approaching wave and moderate to high forecast cape values for
our neck of the woods will lead to a few stronger storms capable
of producing small hail and gusty outflow winds. Atmosphere will
relax a bit overnight, with the stronger convection expected to
diminish, leaving more showery conditions that will persist
through the night. This wave exits early Tuesday, although
additional support moves up into the Four Corners are by midday
Tuesday to keep the unsettled weather rolling. Snow levels will
remain quite high with best accumulating snows above mountain pass
levels through the duration of this event. Could see several
inches of wet snow above 11k with an inch or three near the
summit of the highest passes. The southern mountains and valleys
will be the favorites for more beneficial precipitation as we
continue with our wet October.

Mild temperatures expected again today with most areas running 3
to 6 degrees above normal with cooler weather on Tuesday as the
above mentioned wave and trough axis swing through.

.LONG TERM...(Tuesday night through Sunday)
Issued at 324 AM MDT Mon Oct 22 2018

Showers will continue along the southern and central divide
mountains Tuesday evening before lifting east of the region as drier
westerly flow ushers in behind the departing trough. This trough
will be driven eastward rather quickly by both a stronger jet streak
rounding the base of the trough over the northern Baja into New
Mexico and the remnants of Hurricane Willa moving through old Mexico
and Texas by Wednesday.  H7 temps look to get as low as 2C which
would mean snow levels will be around 10kft. Some isolated
convective showers may linger behind this wave in the west to
northwest flow Wednesday afternoon, but are not expected to amount
to much. High pressure will build strongly to the west Thursday into
the weekend, causing any weather systems to move far northward up
and over the top of the ridge and down the other side. These waves
may clip our northwest divide mountains but otherwise, temperatures
will be moderating to near normal levels.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 324 AM MDT Mon Oct 22 2018

A low pressure system will move into the Great Basin today with
clouds, showers and a few thunderstorms moving from south to north
across eastern Utah and western Colorado. Ceilings will likely
drop below ILS breakpoints from south to north today with local
MVFR conditions in the vicinity of showers. Showers are expected
to expand and intensify in coverage overnight tonight into Tuesday
morning. Mountains will be obscured at times today with frequent
obscuration anticipated tonight and Tuesday.




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