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

FXUS65 KGJT 280944

Area Forecast Discussion
National Weather Service Grand Junction CO
344 AM MDT SAT MAY 28 2016

.SHORT TERM...(Today through Sunday)
Issued at 344 AM MDT Sat May 28 2016

Interesting H5 flow pattern showing up on the 00Z hand analysis
chart. Three rex features extend from the high latitudes of NOAM
to the central CONUS and then off the southeast coast. The left
most low in this pattern will basically stay in place across
southwest Canada...the middle low will be absorbed in the flow and
quickly lift northeast over the next 24 hours and the low in the
east is a tropical depression which will soak the mid atlantic
states into early next week. Closer to home we should see a
downturn in convective coverage this afternoon as we will be in
between system with the next upstream low developing over the
central California coast by late this afternoon. Showers and
thunderstorms will be favored over the terrain this afternoon with
only small chances of a stray shower hitting the lower valleys.
With this downturn and warmer temperatures moving in aloft we will
see afternoon highs bump upward some 5 to 10 degrees in the lower
elevations. The end results however will continue to be on the low
side of normal. Most of the convective activity should go to bed
after sunset but there could be a stray shower linger into the
early morning hours over our southern CWA. High temperatures on
Sunday will approach and possibly exceed normal seasonal highs for
the first time in while as shortwave ridging ahead of the
southwest low pumps in some warmer air aloft. Should be a similar
scenario for showers and thunderstorm development Sunday
afternoon with the focus on the terrain. PV fields suggest the
weakest of waves lifting into the southern CWA in the afternoon
which could favor a small uptick in coverage across the San Juan

.LONG TERM...(Sunday night through Friday)
Issued at 344 AM MDT Sat May 28 2016

The western low moves over southern California on Sun then
approaches the forecast area on Mon. As a result...the southwest
flow will persist. But this flow is not expected to be overly
strong as this slow moving wave nears. Moisture will remain
sufficient for a chance of late day convection each afternoon.
The southern wave will phase with a northern branch trough which
will pass over the area on Tue. Look for increased winds and a
better chance of showers and thunderstorms.

A more substantial ridge of high pressure will build over the west
for the remainder of the week. This will result in drier and
warmer conditions with highs possibly topping normal values by the
end of the work week. Scant moisture will keep a few afternoon
showers/thunderstorms possible over the mountains.


.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 344 AM MDT Sat May 28 2016

VFR conditions will dominate the forecast the TAF sites over the
next 24 hours. Showers and thunderstorms will again develop over
the higher terrain after 18z today with a few drifting over the
valleys late in the afternoon. Gusty winds to 35 mph and brief
rain could accompany the strongest storms. Expect the mountains
to be obscd at times with brief ILS cigs near showers. The
probabilities of TAF sites being impacted by showers are very low
and this will be relayed in the 28/12z forecast. These storms
will collapse by sunset and mainly clear skies and light winds
area expected overnight.


.GJT Watches/Warnings/Advisories...
CO...Flash Flood Watch through this afternoon for COZ007-009.



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