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Latest ZFP from WFO RIW
	
National Weather Service Local Forecast for Star Valley Ranch
Updated: 18 Aug 22:04 pm MDT

Tonight... Areas of smoke. Clear, with a low around 46. East
northeast wind 5 to 8 mph. 

Sunday... Areas of smoke. Sunny, with a high near 79. East wind
5 to 7 mph becoming calm. 

Sunday Night... Areas of smoke. Clear, with a low around 46.
Calm wind becoming east southeast 5 to 8 mph in the evening. 

Monday... Isolated showers and thunderstorms after noon. Some
of the storms could produce gusty winds.  Increasing clouds, with a
high near 79. East wind 5 to 7 mph becoming south in the morning. 
Chance of precipitation is 20%.

Monday Night... Scattered showers and thunderstorms before
midnight, then isolated showers. Some of the storms could produce
gusty winds.  Mostly cloudy, with a low around 47. South wind 5 to 7
mph becoming east southeast in the evening.  Chance of precipitation
is 30%.

Tuesday... Mostly sunny, with a high near 81. East southeast
wind 5 to 8 mph becoming west in the afternoon. 

Tuesday Night... Partly cloudy, with a low around 48. West wind
5 to 7 mph becoming calm  after midnight. 

Wednesday... A 10 percent chance of showers and thunderstorms
after noon.  Mostly sunny, with a high near 80.

Wednesday Night... A 20 percent chance of showers and
thunderstorms before midnight.  Partly cloudy, with a low around 51.

Thursday... Sunny, with a high near 80.

Thursday Night... Mostly clear, with a low around 48.

Friday... Sunny, with a high near 81.

Friday Night... Mostly clear, with a low around 49.

Saturday... Sunny, with a high near 83.

	

Latest AFD from WFO RIW
	National Weather Service Riverton WY
129 PM MDT Sat Aug 18 2018

.SHORT TERM...This evening through Tuesday

This mornings cold front and the associated band of showers,
continues its exit over Johnson and Natrona counties. Although skies
had quickly cleared behind these showers, clouds (and additional
showers) have already begun to develop over the Absarokas and Wind
River Mountains. Unfortunately, smoke has also already begun to
filter back in from the west.

Showers and storms will continue to develop over the western
mountains this afternoon. Most of this convection will be along and
north of the Divide, including Yellowstone National Park. These
storms will move from northwest to southeast over these portions
east of the Divide. With the clearing conditions, cooler
temperatures aloft and residual low level moisture, there will be
enough instability for strong storms in these areas this afternoon.
Hail and strong gusty winds will be the main threats with these
storms. Elsewhere, isolated thunderstorms will be possible.

Despite the high (middle to upper 40s/low 50s) dewpoints across
southern and southwestern portions this morning, have opted to issue
a Red Flag Warning across southern portions of the forecast area.
Guidance continues to keep RH at critical values, so coupled with
the expected gusty west-northwest winds this afternoon and isolated
thunderstorms, felt better to issue a warning.

As storms weaken this evening, showers will be confined east of a
Cody-to-Casper line due to wrap around moisture from the upper low.
Gusty northerly winds will aid in advecting drier air over northern
and eastern portions. At the same time, the overnight showers will
begin to end from north to south. Additional showers and possibly
thunderstorms will redevelop over the northern and central
mountains Sunday afternoon.

Models continue to resolve a shortwave moving over western portions
Monday afternoon, bringing the next round of showers and
thunderstorms to the area. Some of this activity could linger
overnight Monday night.

.LONG TERM...Tuesday night through Saturday

Next shortwave to our west will be weakening and shearing apart with
minimal energy remaining over our area to start the period. Cold
front pushing south Tuesday may keep a focus of some storms in
mainly our south half into Tuesday evening. The parent trough will
likely be pushed back towards us from the west late in the day
Wednesday into Wednesday night with an increasing threat of showers
and thunderstorms spreading into the west by Wednesday night. As
this shortwave weakens and moves across us Thursday, there will
be some marginal instability east of the Divide, especially ern
third for some thunderstorms. Another weak wave may skim the area
Friday, but with limited moisture/forcing. A few storms could
fire off the Uintas and hit srn Sweetwater County. A stronger
system is expected to move into the Pacific Northwest Saturday
with an increasing sw flow over our area ahead of the associated
cold front. Some limited moisture will be drawn nwd into the swrn
zones with a little better chance of some storms forming over the
nrn UT mtns and moving into our swrn zones. It will be warm to
quite warm through the period with mostly 80s east of the Divide
Wed and Fri with a few more 90s possible Thursday and especially
Saturday with the increasing sw flow.

&&

.AVIATION...For the 00Z TAFS through 00Z Monday

A strong weather system will bring areas of gusty to strong west
through north wind and areas of showers and thunderstorms into
Sunday morning. The best chance for thunderstorms will be across the
northwest and along and east of the divide including KCOD, KWRL,
KLND, KRIW and KCPR. Showers and strong north wind will continue
overnight around Johnson County including KBYG down to around KCPR.
MVFR conds due to low cigs are expected between 08z and 14z from
KBYG to KCPR. On Sunday, a few morning showers will occur between
KBYG and KCPR. Otherwise, expect only isolated afternoon showers in
and near the mountains Sunday with VFR conds after the morning low
clouds lift

&&

.FIRE WEATHER...

...RED FLAG WARNING IN EFFECT FOR SOUTHWESTERN WYOMING THIS
AFTERNOON...

Showers with isolated embedded thunderstorms will be confined east
of the Divide, with the best chances over the Bighorns, Johnson
and Natrona counties. Winds will quickly weaken by sunset and
begin to turn more northerly. With this turn, winds will remain
gusty tonight across Johnson County and eastern portions of the
Bighorn Basin. Temperatures will be 5 to 10 degrees cooler across
the area tonight. RH values will be 20 to 30 percent higher from
281 to northeast portions of 279, and 20 to 40 percent lower over
414, 277, 278 and western portions of 279.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for WYZ277>279.

&&
	

Latest GFS MOS for JAC
	KJAC   GFS MOS GUIDANCE    8/19/2018  0000 UTC
DT /AUG  19            /AUG  20                /AUG  21          /
HR   06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 18 00
X/N                    76          44          74          46    76
TMP  56 51 44 52 65 75 76 64 54 50 46 54 67 72 66 58 54 50 48 68 72
DPT  44 42 40 43 44 38 35 38 40 41 40 44 45 42 43 49 49 48 46 46 38
CLD  CL CL CL CL CL SC CL CL CL FW SC SC OV OV OV OV BK BK SC SC BK
WDR  36 01 01 36 20 22 23 29 36 01 36 24 19 22 20 29 01 01 36 19 22
WSP  11 08 07 03 04 05 07 10 05 08 07 04 05 08 09 14 10 06 04 07 08
P06         0     0     0     3     2     0    24    32    23  2  6
P12                     1           3          24          42     6
Q06         0     0     0     0     0     0     0     1     0  0  0
Q12                     0           0           0           1     0
T06      2/ 0  1/ 0  9/ 0 11/ 0  3/ 0  4/ 0 34/ 4 27/ 4 14/ 0 32/ 0
T12            2/ 0       12/ 0        6/ 1       55/ 7    15/ 1
CIG   8  8  8  8  8  8  8  8  8  8  8  8  8  8  7  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



850
FOUS24 KWNO 190000

-----------------

KJAC   GFSX MOS GUIDANCE   8/18/2018  1200 UTC
FHR  24  36| 48  60| 72  84| 96 108|120 132|144 156|168 180|192
     SUN 19| MON 20| TUE 21| WED 22| THU 23| FRI 24| SAT 25|SUN CLIMO
N/X  44  76| 43  75| 45  78| 45  79| 48  76| 43  76| 41  75| 40 41 77
TMP  46  74| 45  68| 47  75| 47  73| 50  72| 44  73| 42  71| 40
DPT  41  36| 41  40| 45  39| 40  44| 42  36| 38  32| 36  33| 36
CLD  PC  CL| PC  OV| OV  PC| PC  PC| OV  PC| CL  PC| PC  CL| CL
WND  10   7| 10  13| 13   9|  9   8|  8  18| 16  16| 16  15| 15
P12  11   6| 10  18| 44   4|  7   8| 40  11| 10  10|  8   9|  8999999
P24      12|     27|     47|     16|     45|     11|     11|      999
Q12   0   0|  0   0|  1   0|  0   0|  2   0|  0   0|       |
Q24       0|      0|      1|      0|      1|      0|       |
T12  19  16| 18  34| 38  35| 23  35| 36  21| 10  20| 14  16| 11
T24        | 33    | 58    | 43    | 54    | 22    | 23    | 20

	
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