Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
690 FXUS65 KRIW 061007 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 407 AM MDT Thu Jun 6 2024 .KEY MESSAGES... - Warm and dry conditions expected today. - Shower chances increase tonight through the weekend, but most of the area remains warm and dry. - Increased mountain snowmelt expected with minor river and stream flooding possible. && .DISCUSSION... Issued at 326 AM MDT Thu Jun 6 2024 After the warmest day of the year thus far for most locations, temperatures will warm further today as ridging helps 700mb temperatures reach 13 to 15C over the area. Nearly all lower elevations will see highs peak in the 80s, with a handful of locations approaching 90 this afternoon. Otherwise, it will be dry with plenty of sunshine. Unlike Wednesday, wind will be much more subdued today, though not calm (obviously- this is Wyoming). With a drier airmass mixing down, relative humidity will drop to around or below 15 percent across much of central and southern Wyoming. Fortunately, the lighter winds will help mitigate fire weather concerns. A weak shortwave will squash the ridge a bit this evening, coinciding with increasing Pacific moisture. This may lead to a few showers moving in from Idaho overnight. We may need to increase PoPs across western Wyoming tonight if the current CAM solutions of showers hold. A better bet for convection will be Friday morning and afternoon, especially across southwestern Wyoming and the higher elevations of western Wyoming. Otherwise, Friday will be a similarly warm day, though the added convective activity may end up keeping temperatures a bit cooler than currently forecast. Guidance paints a similar picture for the weekend; highs will generally peak in the upper 70s or 80s with continued afternoon convection. The best chances will be over the western mountains (around 30-40 percent). There is still some models hinting at a stronger mid-level wave clipping the area as it swings through Idaho Sunday evening. This would bring more widespread showers to northern and western Wyoming Sunday night. Further out, ensemble cluster mean guidance still favors anomalously high 500mb heights to persist through next week. This would keep warm and mostly dry conditions across the area. Given the warm temperatures this week and next, rivers and streams will continue to be monitored for flooding potential as mountain snowmelt is exacerbated. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 406 AM MDT Thu Jun 6 2024 VFR conditions expected at all TAF sites for the entirety of the period. Light winds and clear skies mainly to start the period. Winds pick up some at BPI, RKS, and PNA after 20Z with mixing to the surface during peak heating with an approaching weak system to the northwest. Winds will diminish with radiational cooling after around 02Z with increasing upper level clouds through the afternoon and evening. Light winds less than 10kts for sites east of the Divide. Dry conditions expected with no other weather elements forecasted. The exception may be some showers approaching KJAC after 07Z but not enough confidence to include in the forecast at this time. 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...Hattings