Area Forecast Discussion
Issued by NWS Salt Lake City, UT
FXUS65 KSLC 252349 CCA
Area Forecast Discussion...CORRECTED
National Weather Service Salt Lake City UT
550 PM MDT MON JUL 25 2016
.SYNOPSIS...An upper level ridge over the Great Basin will result
in continued hot conditions across the area. Remnant moisture will
allow isolated storms to develop across all but far northern Utah
today and Tuesday before a more westerly flow aloft dries the
region out by midweek.
.SHORT TERM (UNTIL 12Z THURSDAY)...A weak trof sits along the
west coast this afternoon with a swly flow over Utah. Limited
moisture has spread north into the state and covers all but the
nwrn 1/4 of the CWA. Convection has fired over the mtns along and
east of the I-15 corridor from about Provo south and over the
Uintas. A few cells have formed west of Milford and are also
drifting off the terrain into the ern valleys.
The deepest moisture is limited to the southern CWA roughly south
of a line from St George to Green River and there remains a small
threat of heavy rain from cells in that area. Otherwise storms
today should be fairly high based with more wind than rain.
Expect convection to persist over these areas into tonight and
a few weak cells could spread farther north thru western valleys
after midnight as another weak disturbance crosses the north.
The mid level ridge starts to recenter westward Tue with drier
westerlies starting to spread into west central and nwrn Ut.
Moisture is expected to linger over the mountains as well as
across the southern and eastern valleys with another round of
convection in these areas but probably less numerous. This drying
spreads across pretty much the entire CWA on Wed and have removed
pops from the forecast for that day.
Temps will stay hot across the CWA with SLC reaching 100 today and
highs along the Wasatch Front of 100 or better in the forecast
thru at least Wed.
.LONG TERM (AFTER 12Z THURSDAY)...Upper level ridge remains
anchored over the Great Basin late this week before re-centering
over the central plains by the end of the weekend. The hot weather
will continue across the area late this week and into the weekend.
Could see quite an impressive run of 100+ degree days along the
central and southern Wasatch Front by the end of the week with
high temps generally 105-110 late this week in Dixie.
By Thu and Fri...ECMWF and GFS both indicate the potential for
moisture to work to the western edge of the mid-level high situated
over Arizona and then into southwest Utah on weak southwest flow
aloft. Given this trend have added a slight chance of thunderstorms
to far southwest Utah on Thu and increased the coverage across the
southwest a bit for Friday. Upper level high then shifts east
allowing moisture to stream further north into Utah over the
Sunday and Monday...Extended forecast models indicate an upper level
trough feature swinging through the Pacific Northwest late in the
weekend. The latest run of the GFS has backed off a bit on how far
south this digs through Washington State and Oregon, while the
latest iteration of the EC drops this farther south. However,
differences still are present as the EC keeps this feature much
farther north allowing the ridge to flatten out through the Great
Basin, while the GFS has a more prominent southwest-flow trough
pattern moving through the Great Basin into early next week.
Differences aside, with increasing moisture advertised into the
weekend, temperatures should begin to decline slightly with
increasing afternoon convection across the southern portion of the
county warning area.
.AVIATION...There is a 20 percent chance of showers impacting the
SLC terminal between 22Z and 04Z, with gusty erratic winds as the
most likely impact. Otherwise, expect winds to switch back to the
southeast around 03-05Z.
.FIRE WEATHER...The southwest flow over the district today has
spread moisture north to about I-80 and isolated to scattered
showers and thunderstorms will continue south of there well into
this evening. Drier westerly flow will begin to spread across
western Utah on Tuesday with enough moisture remaining over the
mountains and east for another round of isolated afternoon
thunderstorms. Hot and dry conditions over the north and west
Tuesday will expand across the entire district on Wednesday as the
drier west to northwest flow spreads into the south and east. It
appears a little moisture will start to move back into southwestern
Utah on Thursday then increase through the weekend bringing a
renewed threat of afternoon thunderstorms. This next round of
thunderstorms looks to be on the dry side at least for the first
part of the weekend with a chance of dry lightning.
For more information from NOAA`s National Weather Service visit...
For frequently asked questions about the Area Forecast Discussion