Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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697 FXUS65 KRIW 131728 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1128 AM MDT Thu Jun 13 2024 .KEY MESSAGES... - Weak convection over southern portions of the CWA Thursday. - Some minor flooding issues due to snowmelt but most waterways are on the decline. - Elevated fire weather risk Saturday afternoon. - Cooler late weekend and into next week with low confidence return of moisture as well. && .DISCUSSION... Issued at 1250 AM MDT Thu Jun 13 2024 IR currently depicts mainly clear skies across the CWA with some clouds pushing through the southern portions of the state. This will be the area for some afternoon convection that will push slightly north of east towards the Casper area into the evening hours. Weak convection and short lived is expected with no significant impacts. Otherwise, ridging will continue to extend in from the south with a weak low over the southwestern US that will push the aforementioned mid level support to spark a few storms and sporadic rain showers. Much weaker winds with a more relaxed gradient, so fire weather is not a concern. Friday will see a bit more activity for areas east of the Divide as a deepening low pushes out of the GOA towards the Pacific northwest coast. A subtle shortwave looks to push through the CWA off of it during the afternoon and early evening hours. Warm temperatures continue with snowmelt becoming less of a concern as waterway levels steadily decline as time goes on. As the low slowly pushes further eastward and deepens due to increasing divergence aloft, the gradient will tighten up on Saturday. This will give way to some gusty southwest winds and an elevated fire weather concern with humidity values dropping with the warm temperatures. Troughing will continue to elongate southward Sunday as a cold front drops through during the afternoon hours that will make for a tricky temperature forecast with cooler air behind it. Regardless of timing, below average temperatures can be had to start next week and for a few days. With the slowly approaching low as many models have it doing, an increased chance in precipitation will follow. There is still much discrepancy on how much and when through mid week. Nothing looks to be a drought buster, but there should be at least some measurable rain for most during that time span. By mid week, the trough becomes more progressive as it speeds into the upper Great Plains as ridging builds in behind it. This will bring dry conditions and a warming trend once again to end the work week and into the following weekend. All in all, mainly quite weather conditions being hot and dry through the weekend becoming cool and a bit wetter through mid next week before reverting back to more of the same beyond. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1128 AM MDT Thu Jun 13 2024 VFR conditions are expected at all terminals through the period. There is a slight chance of isolated convection (mainly virga showers) this afternoon; 10% chance at KRKS, KLND, and KRIW; 30% chance at KCPR. A PROB30 group has been included at KCPR, where the best chance for thunderstorms exists. A 10% chance of convective shower activity continues through much of the night at the aforementioned terminals, but no impacts are expected. Winds will remain mostly light (gusts less than 20kts), though a gusty thunderstorm outflow late this afternoon across the southwest or Wind River Basin cannot be ruled out. Any breezy conditions will diminish towards sunset and winds will be light through the night, though will begin to tick back up again Friday morning at several terminals. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Lowe AVIATION...Hensley