Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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711
FXUS65 KSLC 271031
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
431 AM 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)...The axis of the upper trof
sits across central UT early this morning with the associated cold
front now out of the state. A band of weak showers along the trof
axis have been gradually dissipating overnight and expect this
trend to persist through the morning. Models indicate sufficient
instability this aftn for some isolated convection over the mtns
from the Uintas south while the Wasatch range remains too stable.

Temps today will stay on the cool side across the north and run
5-10 degrees cooler than yesterday over the south now that the
front has passed.

The ridge along the coast begins to shift inland today and ends up
centered over the Great Basin by Sun eve. Rising heights and a
warming airmass will be reflected in the max temps Sunday thru
Mon. Isolated aftn mountain convection is also expected again both
days.

.LONG TERM (After 00z Tuesday)...A strong amplified ridge is
encompassing the West CONUS starting the work week ahead, as
temperatures continue a warming trend through late week. The flow
aloft turns southwesterly by Wednesday ahead of a Pacific trough
slotted to move onshore by mid to late week. Retained some of the
high elevation PoPs in the forecast through Wednesday.

Both the EC and the GFS advertise a Pacific Northwest trough
system swinging into the West Coast Wednesday, however the last
several model runs have been quite inconsistent. Par for the
course, the latest (00z) EC and GFS are not quite in agreement.
The GFS closes the Low off up over Washington/Oregon while the EC
has a very open and elongated wave, almost a split system feature
(which is in contrast to the previous EC which had a split, cut
off low). Confidence in either model solution is quite low,
however my inclination was to lean more with the EC due to less
variance in run to run changes.

All this said, the extended forecast was blended heavier with EC
type precipitation chances while still trying to maintain some GFS
coverage and amounts. The overall pattern, with models aside,
looks to be quite unsettled in contrast to the current pattern as
of Saturday May 27th. 700mb temperatures will warm through
Wednesday before cooling slightly into the following weekend,
while still remaining above seasonal normals area wide.

&&

.AVIATION...VFR conditions are expected at the SLC terminal
through the valid TAF period. Northerly winds are expected to
persist through the day before switching to the southeast after
03z this evening.

&&

.FIRE WEATHER...A cool northerly flow has spread over the district
that will continue through today with breezy north winds in most
areas. A band of light showers across central Utah in the morning
will dissipate this afternoon. A few thunderstorms are possible
over the mountains in the afternoon. High pressure builds over the
region Sunday through Monday and transport winds drop off with
clearing indices becoming poor most areas. Expect a warming trend
to begin Sunday and last into mid week. Increasing instability as
temperatures warm will produce deeper mixing and clearing indices
will improve Tuesday and Wednesday. Isolated afternoon mountain
thunderstorms are possible each day.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

SHORT TERM/FIRE WEATHER...Wilensky
LONG TERM/AVIATION...Dewey

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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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