510
FXUS65 KSLC 101044
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
444 AM MDT Fri May 10 2024

.SYNOPSIS...A low pressure system spinning across Nevada will
maintain easterly winds across northern Utah through midday, as
well as fuel showers and thunderstorms across the region. This low
will move east along the Utah Arizona border Saturday, bringing
another round of showers and thunderstorms. Temperatures across
the region will trend warmer through the weekend into early next
week.

&&

.SHORT TERM (Through 12Z/6AM Sunday)...An elongated mean upper
low stretches across central Utah westward into central Nevada
early this morning. Along the northern periphery of this
circulation, easterly flow has become established across northern
Utah/southwest Wyoming, as well as a zone of low level cold
advection over areas north of I-80 and east of I-15. This
continues to drive downslope winds along the northern Wasatch
Front early this morning, where peak winds peaked at 66 mph this
far in Farmington. Away from this area, wind have remained muted
along the eastern Cache Valley and Box Elder county. The setup
remains favorable for winds to continue through at least mid
morning, and will leave going headlines as is.

The upper circulation is forecast to become consolidated around a
circulation across Nevada and drift south through the day today,
with a mid level deformation axis extending downstream from
southwest to northern Utah. A combination of daytime heating, cold
air aloft, and weak forcing associated with this deformation axis
will support showers and a few thunderstorms along the terrain
this afternoon and early evening, with perhaps more widespread
coverage this evening across southwest Utah in closer proximity to
the upper low. As this low begins to eject east and slowly
traverses the Utah/Arizona border region Saturday, cold air aloft
coupled with a wave rotating around the back side of the low will
support another round of showers and thunderstorms along the
terrain. These storms will spread south with time, moving down
drainage across the Grand Staircase region. Given this, have
included possible in the Flash Flood Potential outlook mainly for
small, fast responding basins.

Despite the upper low spinning across the region, temperatures
will trend 2-5 degrees warmer both today and again Saturday as the
airmass gradually modifies.

.LONG TERM (After 12Z/6AM Sunday)...Our main weather story coming up
next week will center around warming temperatures! Temperatures will
be back to their seasonal normals for the middle of May and even a
few degrees above normal. High pressure is expected to be the
dominant weather pattern building in from the west by Sunday but it
is worth a mention here that while the high is dominant, there
remains an exiting low to our east. There may be enough moisture
left over to initiate shower/thunderstorm development in eastern
Utah Sunday afternoon, a trend particularly favored by the SREF
model. If you`re headed out on a boat, or really doing anything
recreational, on Sunday, in the Wasatch Back (Strawberry /
Jordanelle) or western Uintas it would be good to keep yourself
weather aware of the potential for thunderstorms.

Our high pressure area begins to shift slightly southward Monday as
a shortwave traverses through Idaho. This wave may skirt across the
state border and bring an increased chance for rain and
thunderstorms during the afternoon. Similar to yesterday, the wave
isn`t too impressively strong and confidence of widespread impacts
is very low. But it is something to keep watching.

We`re not any closer to getting a consensus on the forecast come mid-
week. Deterministic GFS and ECMWF runs indicate a fairly potent
trough incoming across the Intermountain West and interacting with a
cut-off low to our southwest. A cold front passage may accompany
said trough with further questions as to what becomes of this trough
later in the week. The deterministic GFS incorporates more abundant
amounts of moisture associated with the low/trough compared to the
deterministic ECMWF and ensemble members in no way show a consensus.
There are several members of the GEFS that indicate 0.1 to 0.3
inches of rainfall in the SLC metro with this wave but this again is
the forecast model with the higher range of possible QPF amounts.
Comparatively, a few members of the ECMWF ensemble indicate a few
hundreds of an inch of rainfall but the majority forecast no rain.
Surely we`ll get a better model consensus in the coming days.

&&

.AVIATION...KSLC...VFR conditions are forecast today while high
based clouds continue. Occasional breezy conditions are possible
from the east and southeast through the afternoon.

.REST OF UTAH AND SOUTHWEST WYOMING...Breezy easterly winds are
forecast across OGD/LGU and EVW this morning with occasional breezes
possible through this afternoon. Mid and high based clouds are
forecast at these terminals through the afternoon with P6SM allowing
for VFR conditions. From HCR southward, isolated shower and
thunderstorm development will be possible during the afternoon hours
and potentially could impact terminals. Lightning, gusty outflow
winds and lowered visibilities are possible.

&&

.FIRE WEATHER...A low pressure system centered over southern Nevada
will maintain easterly flow across northern Utah through much of
the day today. The result will be a favorable setup for gusty
easterly winds through midday, with winds becoming locally strong
at times along the eastern benches of the Wasatch Front north of
I-80, as well as the Cache Valley. These winds will peak this
morning then trend downward through the day.

Moisture associated with this low will fuel showers and
thunderstorms this afternoon and again Saturday. These storms
will initially develop over the higher terrain midday, then spread
into the adjacent valleys by mid to late afternoon. The greatest
concentration of showers and thunderstorms will come late this
afternoon and evening across southwest Utah. This moisture
will also keep daytime RH elevated today and again Saturday with
excellent overnight recovery.

Despite the low overhead, the airmass will gradually warm through
Saturday, followed by a more robust warming trend Sunday into
Monday. By Monday afternoon temperatures across the region will
run nearly 10 degrees above normal.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Wind Advisory until 10 AM MDT this morning for UTZ103-105-107.

     High Wind Warning until noon MDT today for UTZ104.

WY...None.
&&

$$

Seaman/NDeSmet

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