Flash Flood Warning 22, NWS Grand Junction, CO

Area Forecast Discussion
National Weather Service Grand Junction CO
1145 AM MDT Fri Jul 27 2018

.SHORT TERM...(Today through Saturday)
Issued at 255 AM MDT Fri Jul 27 2018

Little change with the high pressure that remains centered over
the Great Basin. The difference today will be an uptick in
available moisture as forecast PWATs across the area will range
from .75 to 1 inch. Daytime heating and orographics will aid in
convective development this afternoon. Models also showing some
subtle features moving through the mean flow that may allow some
stronger convection to form. Plenty of CAPE is forecast for the
higher terrain with the San Juans and Uncompahgre Plateau favored
for convection which is expected under these conditions. Gusty
outflow winds reaching 40 to 50 MPH will be possible under the
stronger showers and storms. Also, the Flash Flood Watch
continues for the 416 burn scar as some heavier showers and storms
are likely to develop early this afternoon and move over the
scar.

As usual, most convection will die down shortly after sunset
through a few lingering showers and storms are possible after
that.

Not much change on Saturday as everything stays about the same.
Moisture remains near an inch as daytime heating and orographics
release instability over the region bringing more showers and
storms. Again, models are highlighting the San Juans for heavier
precip amounts. Will hold off on issuing any Flash Flood Watch
for Saturday to see how models do today.

Under high pressure, hot temperatures continue.

.LONG TERM...(Saturday night through Thursday)
Issued at 255 AM MDT Fri Jul 27 2018

Subtle shift in the upper level ridge will send drier conditions
across eastern Utah and western Colorado Saturday night and
Sunday. This will reduce daily convective activity back into the
more isolated variety with focus over the higher terrain. Moisture
will slowly creep back in as we start off the new work week with
precipitable water values climbing from three quarters of an inch
back over an inch by mid-week. This will bring more efficient
rain producing showers and thunderstorms with daytime convection
favoring the higher ridges, drifting over the valleys overnight.
Hard to dial into any specific details at this distance from the
event, but chance will be ramping up for more much needed
rainfall. Little change in temperatures are expected through the
period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1134 AM MDT Fri Jul 27 2018

Showers and thunderstorms will affect higher elevation terminals
today including ASE, TEX and EGE. Thunderstorms may briefly lower
vis to MVFR in periods of heavy rain however VFR is expected to
dominate for most of the day. A few stronger wind gusts may also
affect terminals, including at lower elevations, even if no rain
is seen at airports. Wind gusts over 40 mph will be possible and
will generally be out of the northwest. Convection is expected to
diminish quickly after sunset.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Flash Flood Watch until 8 PM MDT this evening for COZ019-022.

UT...None.
&&

SHORT TERM...TGR
LONG TERM...JDC
AVIATION...MAC

Hazardous Weather Outlook
National Weather Service Grand Junction CO
546 AM MDT Fri Jul 27 2018

COZ001>014-017>023-UTZ022>025-027>029-281200-
Lower Yampa River Basin-Central Yampa River Basin-
Roan and Tavaputs Plateaus-Elkhead and Park Mountains-
Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor-
Central Colorado River Basin-Grand and Battlement Mesas-
Gore and Elk Mountains/Central Mountain Valleys-
Central Gunnison and Uncompahgre River Basin-
West Elk and Sawatch Mountains-Flat Tops-
Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide-
Northwest San Juan Mountains-Southwest San Juan Mountains-
Paradox Valley/Lower Dolores River-
Four Corners/Upper Dolores River-Animas River Basin-
San Juan River Basin-Southeast Utah-Eastern Uinta Mountains-
Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat-
La Sal and Abajo Mountains-Canyonlands/Natural Bridges-
546 AM MDT Fri Jul 27 2018

This hazardous weather outlook is for eastern Utah and western
Colorado.

.DAY ONE...Today and Tonight

Moisture has increased somewhat across the forecast area and will
allow some more robust convection to form this afternoon and
evening. As we've seen lately, the big concern will be gusty
outflow winds from any convection that forms. A Flash Flood Watch
remains in effect for the 416 burn scar as this convection will
produce some locally heavy showers and storms over the scar. Most
convection will die down shortly after sunset.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Saturday will be similar to Friday though a drying trend will kick
in Monday through Wednesday. After that, moisture will increase
allowing more convection to fire.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.