Latest ZFP from WFO RIW

		
National Weather Service Local Forecast for Star Valley Ranch
Updated: 23 Jul 05:45 am MDT

Today... Mostly sunny, with a high near 90. Calm wind becoming
west southwest 5 to 7 mph in the afternoon. 

Tonight... Mostly cloudy, with a low around 58. West southwest
wind around 6 mph becoming light and variable  after midnight. 

Wednesday... Isolated showers and thunderstorms after noon. 
Mostly sunny, with a high near 83. Calm wind becoming west 5 to 9 mph
in the afternoon.  Chance of precipitation is 20%.

Wednesday Night... Mostly clear, with a low around 51. West
wind 5 to 9 mph becoming light and variable  after midnight. 

Thursday... Sunny, with a high near 82. Calm wind becoming west
5 to 8 mph in the afternoon. 

Thursday Night... Mostly clear, with a low around 52. West wind
5 to 7 mph becoming light and variable  after midnight. 

Friday... Mostly sunny, with a high near 82. Calm wind becoming
west 5 to 7 mph in the afternoon. 

Friday Night... A 30 percent chance of showers and
thunderstorms, mainly before midnight.  Mostly cloudy, with a low
around 52.

Saturday... Mostly sunny, with a high near 81.

Saturday Night... Mostly clear, with a low around 51.

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

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

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

		

Latest AFD from WFO RIW

		National Weather Service Riverton WY
116 AM MDT Tue Jul 23 2019

.SHORT TERM...Today through Thursday night

We still have a few showers out there shortly after midnight but
these should end by morning. Tuesday at this point looks to be
another warm to hot day across western and central Wyoming as the
ridge builds further northward. There will be another shortwave
topping the ridge though and this will bring the chance of afternoon
and evening thunderstorms to the area. At this point the best chance
would be across northern Wyoming where the best forcing is, but most
areas will have at least a slight chance of one. The Storm
Prediction Center does have a marginal risk area drawn into
Yellowstone Park. There could be a stronger storm there, but at this
point this looks to be the exception rather than the rule. Strong
winds would be the main threat. For the most part, any hail should
remain off the smaller variety given the high freezing and wet bulb
zero levels. These storms should end shortly after midnight with
mainly dry conditions late tonight into most of Wednesday morning.

The ridge looks to flatten on Wednesday as another shortwave crosses
the area. This will lead to another chance of showers and
thunderstorms. This could be an earlier show but at this point we
kept the morning dry since showers would begin later in the morning
and most of the period would be perceived as mainly dry. There
models are more split on where to put the thunderstorms so we gave
all areas a chance of one. This also looks to a breezier day and
possibly a rather hot one with areas in the Big Horn basin making a
run at the 100 degree mark. These storms should end by midnight with
dry conditions following that.

Ridging then builds back further north again on Thursday. The models
have also trended drier with all the models having dry conditions
across the entire area. The national Model Blend looked WAY too wet.
For now, we removed all POPs except across the far south but even
here I could see removing the POPs if these trends continue. With
much drier dew points, enhanced fire behavior will begin to become
possible. At this point though, winds look borderline at best for
any fire weather highlights and some zones are not critical yet as
well. Something to watch though.

.LONG TERM...

The period will be marked by a somewhat flat ridge, with zonal flow
over the northern CONUS by Sunday. Pacific and monsoonal moisture
will return Friday, as shortwaves begin to rotate back around
along the west side of the high center. These shortwaves will
continue over the forecast area Saturday and exit over the Plains
Saturday night into Sunday. The timing of the cold front continues
to shift between model runs, with the timing of the front now
occurring Saturday through Saturday night. Widespread
thunderstorms continues to be expected across the area, as the
front moves through Wyoming. Drier conditions are expected Sunday
and Monday, as the high center shifts westward over AZ/NV. Drying
of fuels, will continue through the period, coupled with
lightning and gusty thunderstorm winds, fire weather conditions
will need to be closely monitored.

&&

.AVIATION...For the 12Z TAFS through 12Z Wednesday

Widely scattered showers thunderstorms will develop over the area
after 19Z. This activity will continue through 06Z Wednesday. Some
storms will have wind gusts around 30 knots, brief heavy rain, and
small hail. VFR conditions are expected at the terminal sites.
However, MVFR conditions will occur in stronger storms due to
reduced visibility in rain. After 06Z Wed, west of the continental
divide, isolated showers are possible.

&&

.FIRE WEATHER...

Another weather system will cross the area today and bring isolated
to scattered mainly afternoon and evening showers and thunderstorms.
The best chance of storms will be in northern Wyoming and west of
the Continental Divide. Relative humidity will fall into the teens
across much of southern Wyoming this afternoon. However, winds
should remain light to moderate outside of any shower or
thunderstorm. Mixing and smoke dispersal will range from fair to
good West of the Divide to good to very good East of the Divide.
&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
		

Latest GFS MOS for JAC

		KJAC   GFS MOS GUIDANCE    7/23/2019  0600 UTC
DT /JULY 23      /JULY 24                /JULY 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              87          53          81          42       83
TMP  49 61 76 85 82 70 60 57 54 63 74 80 81 68 56 49 43 57 73 81 57
DPT  42 46 49 43 42 48 49 50 49 49 48 46 42 40 38 37 36 37 37 31 37
CLD  CL CL CL BK BK BK OV OV OV BK BK BK FW CL CL CL CL CL CL CL CL
WDR  01 01 19 20 24 36 36 36 19 19 21 21 23 20 36 36 01 19 20 25 03
WSP  03 01 03 06 08 10 04 03 05 08 08 13 13 09 04 05 04 02 10 10 05
P06         0     8     8     1     3     6     0     1     1  1  2
P12               8           8           7           1        1
Q06         0     0     0     0     0     0     0     0     0  0  0
Q12               0           0           0           0        0
T06      7/ 1 37/ 2 22/ 4  3/ 1  6/ 0 40/ 1 13/ 1  0/ 0  0/ 0  4/ 0
T12                 45/ 6        9/ 2       41/ 4        1/ 0  7/ 0
CIG   8  8  8  8  8  8  8  7  7  8  7  8  8  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




498
FOUS25 KWNO 230600

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

KJAC   GFSX MOS GUIDANCE   7/23/2019  0000 UTC
FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192
TUE  23| WED 24| THU 25| FRI 26| SAT 27| SUN 28| MON 29| TUE 30 CLIMO
X/N  89| 52  82| 43  82| 45  82| 50  79| 43  81| 42  83| 47  82 44 80
TMP  85| 53  80| 44  80| 46  77| 51  76| 43  78| 43  80| 48  78
DPT  41| 48  37| 35  31| 38  43| 47  40| 39  34| 37  34| 40  38
CLD  PC| PC  PC| CL  CL| CL  PC| OV  PC| PC  PC| CL  CL| CL  CL
WND   8| 12  16| 15  13| 10   8|  7  10| 10  14|  9  14| 10  15
P12   3|  7   3|  1   1|  2   6| 21  20| 12   7| 11   7|  7  11999999
P24    |      9|      1|      6|     37|     15|     11|     21   999
Q12   0|  0   0|  0   0|  0   0|  0   0|  0   0|  0    |
Q24    |      0|      0|      0|      1|      0|       |
T12  41| 22  31|  7   7|  8  34| 28  35| 20  18| 17  19| 17  27
T24    | 41    | 31    |  8    | 48    | 35    | 29    | 24