Area Forecast Discussion
Issued by NWS Riverton, WY

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 40 41 42 43 44 45 46 47 48 49 50

136
FXUS65 KRIW 302322 CCA
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
231 PM MDT SAT JUL 30 2016

.SHORT TERM...Tonight Through Tuesday

Mid level monsoonal moisture has made it into the far west with some
weak virga showers by mid to late morning. Widely scattered to
scattered dry,lighting storms are still on track for the afternoon
and evening which may make for a rough period for our firefighters
as gusty and erratic winds will add to the breezy ambient flow
already. Storms will last well into the evening with a few lingering
overnight. Moisture will likely gets suppressed as the day wears on
Sunday with isolated storms over the mtns and se sections.
Otherwise, quite warm to hot again. Monday could be very dry with
very low rh`s and some breezy conditions and very warm to hot.
Tuesday will see more wind, continued dry but with some dry
lightning moving into mountains/west and starting to come off the
mountains into the foothills of Central Wyoming late. It will
continue quite warm to hot ahead of our front.

.LONG TERM...Tuesday Night Through Saturday


An area of low pressure will move over the Pacific Northwest Tuesday
evening, helping to flatten the ridging pattern. An increased
southwest flow is anticipated, though the core of the low will
remain on the Canadian border, reducing its influence slightly.

Monsoonal moisture attempting to move into Wyoming will be stopped
across the southern third of the state Wednesday as the area of low
pressure moves east through Montana. Slightly cooler temperatures
are expected in response to this system. Another area of low
pressure will work to move over the Pacific Northwest Thursday
morning, keeping the more zonal flow over the area. Temperatures
will cool more, with limited shower activity anticipated.

Question exists in the path of this second area of low pressure,
which may stall northwest of Washington. If it does not stall, it
still may progress slowly, keeping the cooler temperatures and
limited moisture around through the remainder of the forecast
period.

Saturday afternoon has some promise of bringing shower activity over
at least a portion of the state. The flow becomes more
southwesterly, allowing some monsoonal moisture to move across the
state. Some afternoon showers and thunderstorms may be possible in
response.

&&

.AVIATION.../00Z ISSUANCE/

West of the Continental Divide...KJAC/KBPI/KPNA/KRKS

Showers and thunderstorms will persist through around 09z this
evening. Some showers will remain over the mountains during the
overnight hours. Smoke from nearby wildfires, and cloud development
from showers and thunderstorms will create periods of mountain top
obscurations. After a lull in shower activity overnight, a return of
mountain showers and thunderstorms will be found between 12z and 15z
Sunday, with activity increasing through the afternoon, and may
impact any terminal. VCTS has been included at the majority of
terminals for Sunday afternoon. Any shower impacts may produce brief
periods of MVFR conditions.

East of the Continental Divide...KCOD/KCPR/KLND/KRIW/KWRL

Showers and thunderstorms will have the potential to develop over
the area this evening, and continue through around 09z. The
exception may be KWRL, though it is on the border of mentionable
weather. Showers and storms are favorable over the central
mountains, and gusts from these storms could bring some erratic and
strong wind to area terminals. Most shower activity will weaken by
08z tonight, though the mountains may hold on to light shower
activity through the TAF period. Showers and thunderstorms are
anticipated to return to the area after 18z Sunday, with similar
threats of strong wind. VCTS has been including in many of the
terminals, except KCOD and KWRL. Activity looks like it could stay
south of those terminals, though this will be monitored. Any shower
development over the terminals may result in periods of MVFR
conditions.

&&

.FIRE WEATHER...

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 9 PM MDT
THIS EVENING FOR ZONES 277...283...288...289...414...415 AND
416...

A combination of low relative humidity, Haines indices of 6 and a
gusty breeze will bring critical fire conditions through this
evening for portions of western and central Wyoming. Widely
scattered to scattered mainly dry, gusty thunderstorms will aid in
the critical fire conditions. Smoke dispersal and mixing should be
generally good to excellent. Fire concerns should ease a bit on
Sunday with slightly cooler temperatures, more cloud cover and
somewhat higher relative humidity. On Monday, however, critical fire
conditions may return to parts of the area with a very dry
atmosphere moving in along with breezy conditions and a haines index
of 6. RH recovery could be poor Sunday night. On Tuesday, an
approaching cold front will produce more wind, along with some dry
thunderstorms.

&&

.RIW Watches/Warnings/Advisories...
Red Flag Warning until 9 PM MDT this evening for WYZ277-283-288-289-
414>416.

&&

$$

SHORT TERM...Skrbac
LONG TERM...Branham
AVIATION...Branham
FIRE WEATHER...Skrbac



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