National Weather Service Local Forecast for Star Valley Ranch
Updated: 23 Jun 07:55 am MDT
Today... A 30 percent chance of showers and thunderstorms,
mainly between 3pm and 4pm. Some of the storms could produce small
hail, gusty winds, and heavy rain. Mostly sunny, with a high near 66.
Breezy, with a south wind 7 to 15 mph becoming west northwest in the
afternoon. Winds could gust as high as 21 mph.
Tonight... Isolated showers and thunderstorms before 9pm.
Partly cloudy, with a low around 41. Northwest wind 5 to 14 mph
becoming northeast after midnight. Winds could gust as high as 20 mph.
Chance of precipitation is 20%.
Sunday... Mostly sunny, with a high near 70. Calm wind becoming
northwest 5 to 7 mph in the afternoon.
Sunday Night... Mostly clear, with a low around 44. Northwest
wind 5 to 7 mph becoming calm in the evening.
Monday... Sunny, with a high near 78. Light and variable wind
becoming west 5 to 9 mph in the afternoon.
Monday Night... Mostly clear, with a low around 49. West wind 5
to 8 mph becoming south southeast in the evening.
Tuesday... Sunny, with a high near 78. South wind 6 to 10 mph
becoming west in the morning.
Tuesday Night... Mostly clear, with a low around 47.
Wednesday... Sunny, with a high near 80.
Wednesday Night... Mostly clear, with a low around 48.
Thursday... Mostly sunny, with a high near 80.
Thursday Night... Partly cloudy, with a low around 47.
Friday... A slight chance of showers and thunderstorms. Mostly
sunny, with a high near 73.
National Weather Service Riverton WY
136 AM MDT Sat Jun 23 2018
.SHORT TERM...Today through Monday night
As of today, we are standing at the summit of active weather across
Wyoming for the next several days. The culprit for the active
weather today will be a shortwave that will pivot around an area of
low pressure over Montana and also drag an associated cold front
through the region. And the result will be another round of
showers and thunderstorms across the area, especially in the
afternoon and evening although some will continue into the
overnight. As for the main threats, there are two. The first is
hail. There could be some larger hail in Johnson County. However,
given the high precipitable water values and low wet bulb zero
levels, a larger quantity of small hail may be a bigger threat. The
main threat is heavy rain. However, the models have been backing
off on this a bit. The main threat would be across the Big Horn
range as well as Johnson and Natrona Counties where moisture is a
bit deeper. This also looks to be more related to individual
thunderstorms rather than widespread activity. And as you know, it
is impossible to pinpoint these. We thought about dropping the
watch for areas west of the Bighorn Range but we will punt to the
day shift for the final decision. The showers will likely continue
through the night as well. Today looks like a cool day as well.
We should see some improvement on Sunday. All the models have
trended drier for tomorrow. The one exception may be Natrona County
and possibly the Big Horn Range but even here it does not look as
wet as yesterday. We did reduce POPS across area further west
however as some ridging starts to build into the area. We also made
things a bit sunnier as well. All showers should end after midnight
Sunday.
We look to enter a dry period starting Monday as ridging builds
across the state. The GFS still has some light QPF across the
Bighorn range but this looks suspiciously like the "Bighorn Rain
Forest" effect. This is otherwise known as the models overdoing the
orographic effects on precipitation. As a result, we kept things
dry. Temperatures should also begin an upward trend, averaging 10
degrees warmer than on Sunday.
.LONG TERM...Tuesday through Saturday
A weak cold front is expected to push into northern Wyoming Tuesday
in response to an upper low pushing east across south-central
Canada. Moisture and forcing is limited so any convection should be
confined to the far north mainly along and north of the frontal
boundary. For now will only have slight PoPs mentioned in the far
northern mountains. A dry westerly flow is expected Wednesday with
the weak surface front dissipating. By Thursday and Friday, global
models are showing a trough of various intensities/evolution forming
across the West and pushing across the Rockies late next week into
the weekend. Overall there will be daily shots of convection
especially over the northwest and north with possibly of 1 or 2
Pacific cold fronts impacting the area.
Temperatures are expected to generally 5-10 degrees above average
Tuesday through Thursday with a possible cool down Friday and
Saturday dependent upon frontal timing and coverage of
precipitation.
&&
.AVIATION...12Z Issuance
Through 15Z, very patchy fog will be possible mainly in the western
valleys. A quick round of isolated showers and thunderstorms are
expected mainly north of a KJAC-KRIW-KCPR line between 20Z Thursday
and 02Z Friday. The most confidence is across the far northwest and
north-central areas and will have VCTS for those terminals. Although
there is a chance of convection farther south will keep TS mention
out of those TAF terminal since confidence is lower. The convection
is expected to rapidly shift away during the early evening. Then
after 09Z, some light shower activity could push into far northwest
Wyoming.
&&
.FIRE WEATHER...
A weather system and cold front will drop across the state and
bring some showers and thunderstorms, most numerous in northern and
eastern portions of the area. A gusty wind will continue across
portions of Sweetwater County. Any shower or thunderstorm could have
erratic winds. Relative humidity should remain above critical
levels. Locally wetting rains are possible in thunderstorms,
especially in eastern portions of the area. Mixing and smoke
dispersal will range from fair in the north to excellent in the
south.
&&
.RIW WATCHES/WARNINGS/ADVISORIES...
Flood Watch from this evening through Sunday afternoon for
WYZ005>011-017-019-020-022.
&&
KJAC GFS MOS GUIDANCE 6/23/2018 0600 UTC
DT /JUNE 23 /JUNE 24 /JUNE 25 /
HR 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 00 06
X/N 63 38 68 42 77
TMP 42 55 61 60 58 52 46 43 39 51 61 65 65 58 50 46 42 55 69 75 54
DPT 40 44 43 41 40 44 43 42 39 42 43 40 42 46 47 45 42 47 46 40 45
CLD OV BK BK BK OV OV BK SC FW CL BK BK BK CL CL FW CL CL SC FW FW
WDR 35 20 21 23 28 35 36 01 36 36 33 29 29 33 36 02 35 19 20 23 02
WSP 04 07 13 13 08 06 08 06 06 05 06 06 06 05 03 02 03 02 07 11 04
P06 43 44 36 3 1 10 8 2 0 1 0
P12 59 36 10 8 1
Q06 1 1 1 0 0 0 0 0 0 0 0
Q12 2 0 0 0 0
T06 30/ 5 52/ 3 39/ 0 2/ 0 0/ 0 19/ 2 15/ 0 1/ 0 1/ 0 6/ 0
T12 62/ 4 2/ 0 27/ 2 1/ 1 11/ 1
CIG 8 8 8 8 7 7 8 8 8 8 8 7 7 8 8 8 8 8 8 8 8
VIS 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
OBV N N N N N N N N N N N N N N N N N N N N N
911
FOUS25 KWNO 230600
-----------------
KJAC GFSX MOS GUIDANCE 6/23/2018 0000 UTC
FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192
SAT 23| SUN 24| MON 25| TUE 26| WED 27| THU 28| FRI 29| SAT 30 CLIMO
X/N 65| 42 66| 41 76| 45 78| 40 76| 43 74| 45 67| 43 63 40 75
TMP 58| 43 64| 42 75| 46 74| 41 75| 44 70| 46 62| 45 60
DPT 39| 41 43| 42 41| 42 37| 36 35| 41 41| 42 44| 41 38
CLD OV| OV PC| PC CL| CL CL| CL CL| PC PC| OV PC| OV OV
WND 14| 10 7| 7 10| 10 17| 17 13| 11 9| 10 14| 13 14
P12 43| 36 21| 21 1| 3 6| 4 6| 8 18| 31 32| 33 40999999
P24 | 54| 21| 6| 9| 24| 47| 48 999
Q12 1| 0 0| 0 0| 0 0| 0 0| 0 0| 2 |
Q24 | 1| 0| 0| 0| 0| |
T12 49| 37 28| 28 10| 8 12| 5 10| 7 23| 27 30| 27 27
T24 | 62 | 38 | 10 | 12 | 10 | 36 | 41
|
