Riverton (RIW) — the National Weather Service forecast in plain English · Plaincast

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Partly to mostly cloudy skies will continue this morning, with a slight chance of virga/rain showers over western portions Friday morning.

West winds, with gusts of 25 to 35 mph, will be widespread across the area again today. Temperatures will be slightly cooler today, with readings about 10 degrees cooler over far northern portions due to the proximity of a cold front.

Seasonal temperatures and dry conditions will be in place Saturday. West to southwest winds, with gusts up to 35 mph, will return again over western portions and over the Wind Corridor (southern Lincoln County to Natrona County).

Precipitation chances continue to trend northward, as the track of the storm stays to the north. Little to no precipitation is now expected from the storm on Sunday. The cold front will move through Sunday night, leading to freezing temperatures across western portions of the state again and a cooler day on Monday.

Discussion

Moisture has finally arrived over the Cowboy State, ending this prolonged streak of critical fire weather conditions. Partly to mostly cloudy skies continue over the state this morning, scattering out by midday day. Isolated showers to the west of PIH and SLC will continue to track eastward this morning and move over far western portions of the forecast area around 10Z. Virga is likely from these showers, but amounts around 0.05" will be possible over the Tetons/Gros Ventres and toward Union/Togwotee Pass. These showers may cross the Divide and move over the Upper Green River Basin, after sunrise this morning, but will likely stay as virga. These showers are expected to end by 18Z, with dry conditions expected through the rest of the day. There is a 10% chance for virga showers over areas east of the Divide late in the afternoon as a cold front drops southward.

Widespread gusty winds will be the main concern again today, with west wind gusts of 25 to 35 mph occurring across the forecast area this afternoon. The exception will be portions of the Bighorn Basin and the northern half of Johnson County. Northwest wind gusts up to 30 mph will occur in these areas as a cold front progresses southward through the afternoon. The front will pass through the Bighorn Basin and Johnson County by 00Z Saturday (6pm), quickly reaching the Casper area and Riverton between 01Z and 03Z, eventually becoming stationary along the Divide by 06Z. Temperatures will much cooler today, especially east of the Divide, running about 5 to 10 degrees cooler. This will apply to far northern portions, due to the proximity of the front.

Models have become aligned with the much talked about storm system for this weekend, with not much change from yesterday with the forecast track. The storm system is still forecasted to drop southward along the West Coast tonight into Saturday. The aforementioned cold front will gradually retreat northward Saturday afternoon, due to an increase in southwesterly winds. The front looks to get pushed into the Bighorn Basin and further north into Sheridan County through Saturday afternoon. Apart from isolated showers and thunderstorms over eastern portions of Sweetwater County Saturday afternoon, conditions are expected to remain dry. Precipitation chances continue to be pushed northward as the storm stays further north in MT. Little to no precipitation is now expected from this storm. The associated cold front will push through the Cowboy State Sunday night, clearing the forecast area by 12Z Monday. Sub-freezing temperatures will return to western portions Sunday night/Monday morning, with readings in the upper 30s to lower 40s elsewhere. Dry and cooler conditions will be in place Monday, with highs in the 60s to near 70 degrees across the area. Conditions will remain dry with seasonal temperatures Tuesday. A storm system may impact the region Wednesday, but confidence is low at this point as colder, Canadian airmasses begin to drop southward.