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000 
FXUS65 KRIW 222053
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
253 PM MDT Thu Jun 22 2017

.SHORT TERM...(This evening through Sunday)
Issued at 251 PM MDT Thu Jun 22 2017

Cool mostly dry high pressure with northwest flow aloft will limit
showers to the northern mountains through Sunday with a series of
cold fronts from Canada keeping temperatures below normal with 
north to northeast winds in the north and west winds across the
far south. 

.LONG TERM...(Sunday night through Thursday)
Issued at 251 PM MDT Thu Jun 22 2017

By Sunday night the steering winds will relax as the ridge builds in 
from the west and any breezy areas will see diminishing winds. The 
long wave ridge over the western United States and the long wave 
trough over the east will flatten just a little as a shortwaves 
rides up and over the ridge during next week. The GFS is the most 
aggressive with this shortwave and the asct closed low tracking east 
across Southern Canada next Tuesday and Wednesday. The GFS actually 
depicts a lead shortwave on Tuesday with the main troughpa 
Wednesday. Then high pressure builds in from the west again by 
Thursday. Monday will be a hot and dry day with highs in the 90s at 
the lower elevations east of the divide and low 80s west. Then by 
Tuesday the steering flow will increase and become increasingly 
difluent ahead of the lead shortwave and will result in isold 
thunderstorms in Northern Wyoming late Tuesday with the main 
shortwave and asct difluent flow giving Northern Wyoming another 
round of isold convection late Wednesday. Will favor a blend of the 
models and will depict low pops Tue/Wed to cover the uncertainty of 
pops for Tuesday as the Canadian and Euro would suggest quieter 
weather Tuesday as opposed to the GFS. Tuesday will continue hot 
east of the divide ahead of the main shortwave. Highs will then cool 
to the 80s Wednesday and 70s Thursday behind the trough and 70s 
Wednesday and 60s Thursday out west as h7 temps of 4C move into 
Northwest Wyoming by Wednesday morning. Instability appears to be 
relatively weak Tue/Wed with much better instability to our east 
over the Plains states. West winds will increase Tuesday and 
Wednesday ahead of the approaching troughpa. Fire danger will 
increase Tuesday and Wednesday, especially east of the divide where 
the min RH will dip to the low to upper teens along with that 
increase in wind. A for any river flooding, although temps will 
increase at the beginning of the week, much of the stored mstr in 
the mtns will have been depleted, especially in the Southern Wind 
River Mtns by then.
&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 251 PM MDT Thu Jun 22 2017

VFR will prevail at all terminals through 12Z/Fri. A cool front will 
bring northerly oriented winds of 15-25kts (with higher gusts) has 
pushed south to the divide this morning. Generally few clouds 
expected around the forecast area through the period. A second cool 
front with gusty northerly winds will again burst through the region 
this (Thursday) evening...affecting most terminal sites east of the 
Divide. LLWS possible with the frontal passages at some locations.

&&

.FIRE WEATHER...
Issued AT 251 PM MDT Thu Jun 22 2017

Cool mostly dry high pressure with northwest flow aloft will limit
showers to the northern mountains through Sunday with a series of
cold fronts from Canada keeping temperatures below normal with 
north to northeast winds in the north and west winds across the
far south.  The air mass should mix out enough in hte lower levels
for good smoke dispersal in the afternoons and early evenings. 

&&

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

$$

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