Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 272145
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
345 PM MDT Sat May 27 2017

.SYNOPSIS...A cool northerly flow will be over the area today. A
warming trend starts Sunday and continues into mid week.

&&

.SHORT TERM (Through 00Z Tuesday)...A very weak disturbance aloft is
moving southward across western Wyoming this afternoon producing
scattered clouds and just a few faint radar echoes. Since
temperatures will continue to warm this afternoon have added a
slight chance of a shower or thunderstorm to the northern mountains
and Uintas for this evening. The only other place where a slight
chance for a shower or thunderstorm will occur is down the spine of
central and southern mountains.

With mainly clear skies after midnight tonight the temperatures will
cool to within a few degrees of last night low temperatures. Dry
conditions will occur later tonight into Sunday afternoon. However,
a slight increase in instability is expected over the northern
mountains and Tavaputs as daytime heating helps to destabilize the
air mass which still contains some moisture. Continued with the
minimal threat of showers and thunderstorms. The rest of the area
should be sunny with temperatures warming to a few degrees above
normal.

Memorial Day will be another 5 degrees warmer in general across the
CWA with isolated showers and thunderstorms confined to the higher
terrain from Boulder Mountain northward to the Uintas.

.LONG TERM (After 00Z Tuesday)...The ridge axis shifts over the
Great Basin Monday night and Tuesday, continuing the warming trend
across Utah and southwest Wyoming. A little additional moisture
and increased southerly flow could allow a few showers to drift
into southern Utah valleys Tuesday afternoon/evening, but in
general the diurnal mountain convection should be similar to Monday.

The ridge continues to shift eastward on Wednesday, as an
elongated trough pushes into the west coast. Ahead of this trough,
models show a decent increase in mid-level moisture and
instability, so have increased POPs across most of the area
Wednesday; that said, any convection will be more likely to
produce strong gusty winds than decent rainfall.

Once this trough moves into the Great Basin, models continue to
struggle on how much the trough splits, and the potential track
that it takes. In the 12Z runs, the GFS is the most bullish in
bringing a more direct- hit trough into Utah Thursday, while the
Canadian lifts the trough north into Idaho, and the ECMWF splits
the trough severely, digging part into Arizona and and lifting the
rest into Idaho.

Needless to say, confidence in details remains low Thursday
onward. The current forecast keeps the temperatures on the warm
side, similar to the ECMWF and Canadian solutions. However, given
that precipitable water values will likely increase on Wednesday,
convection will probably continue on Thursday even if forcing is
weak. As such, have kept broad-brushed mentionable POPs in the
forecast through the end of the week.

&&

.AVIATION...VFR conditions will continue at the SLC terminal tonight
and tomorrow. Northwesterly breezes are expected to switch to the
southeast around 02z-04z this evening.

&&

.FIRE WEATHER...A cool northerly flow over the region today will
become much weaker as the ridge builds in over the region Sunday
into early next week. Temperatures will warm each day through
Wednesday with most areas seeing temperatures about 10-15 degrees
above normal Tuesday through Thursday. A very slow increase in
moisture is expected over the region through Tuesday but this
should only be enough to fuel isolated afternoon and evening
thunderstorms.

A trough moves onto the West Coast Wednesday but the models are
at odds as to its strength and so confidence to a tap of sub
tropical moisture into the Great Basin is questionable. Warm
temperatures will continue most likely but there may be an
increase of showers and thunderstorms later in the week.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Flood Watch from Tuesday morning through Saturday evening for
     UTZ001-007.

WY...None.
&&

$$

SHORT TERM/FIRE WEATHER...Struthwolf
LONG TERM...Schoening
AVIATION...Van Cleave

For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity

For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php



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