Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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633 FXUS65 KRIW 050954 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 354 AM MDT Wed Jun 5 2024 .KEY MESSAGES... - Warm, dry, and windy conditions expected today leading to elevated fire weather concerns this afternoon. - Warming trend continues through the end of the week. Showers are possible on Friday (25-50 percent), but most of the area will remain dry. - Weekend will see a better chance of afternoon showers. - Increased mountain snowmelt expected given warming temperatures. && .DISCUSSION... Issued at 341 AM MDT Wed Jun 5 2024 Warm and dry conditions are expected across the area today as ridging increases over the region. This will mark the beginning of a warming trend through the end of the week, with the potential for three consecutive days of the warmest temperatures of the year thus far for many locations. Today, highs will peak 8-9 degrees above normal, or generally in the upper 70s west of the Divide and lower 80s east. The one exception today will be across the northern half of Johnson County. This area will get clipped by a cold pool associated with a weak front dropping south out of Montana, keeping high temperatures more around normal. Otherwise, with aligned 700mb and upper level flow sandwiched between the ridge and a trough to our east it will be another windy day for the area. Wind will ramp up through the morning, with west/northwesterly gusts of 30+ mph across western, central, and southern Wyoming. The Bighorn and Powder River basins will see a more northerly wind as the front pushes south through the afternoon. With the dry and windy day, elevated fire weather conditions are expected for much of the area through the afternoon. Wind will quickly decrease with sunset. Temperatures warm further on Thursday, with nearly all lower elevations seeing temperatures in the 80s. A few locations may reach 90. With the warmer and drier airmass, humidity will drop to around/below 15 percent, keeping elevated fire weather conditions going. Lower wind speeds will play a mitigating factor in this, however. Models are hinting at a weak shortwave arriving in the Thursday night/Friday timeframe. This added lift combined with slightly increased Pacific moisture will return shower chances to the area, with the best chances Friday afternoon. However, chances remain on the lower side (generally below 50 percent), and most of the area will be dry and warm once again. Given the warming temperatures through the week, rivers and streams will continue to be monitored for flooding potential as mountain snowmelt increases. The overall ridging pattern is currently favored to persist through the weekend, though with continued disturbances moving through the flow. Accordingly, the forecast reflects a still warm but slightly cooler weekend, with better chances for afternoon convection both days. Model solutions diverge dramatically by early next week. Ensemble cluster mean guidance currently favors anomalously high 500mb heights to persist through next week. This would keep warm and mostly dry conditions across the area. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 950 PM MDT Tue Jun 4 2024 Clouds will continue to decrease central and northwestern portions of the forecast area to start the TAF period, but SKC skies are not expected until 18Z. Most of these clouds will linger over the mountains. Winds are expected to have decreased (11 kt or less) by the start of the forecast. This will be relatively short-lived, as gusts around 25 kt will return across the area between 14Z and 18Z. Gusts of 30 to 35 kt will occur at KCPR, KRKS, KRIW and KBPI after 18Z. These winds will once again decrease by 02Z, becoming 12kt or less. A notable shift to the north-northeast will also occur for terminals east of the Divide after 00Z. 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...Myers AVIATION...LaVoie