####018006039#### FXUS65 KCYS 110821 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 221 AM MDT Sat Jul 11 2026 .KEY MESSAGES... - Weak precipitation may be possible for the southern Laramie Range and into Laramie County, but dry surface conditions will likely limit much precipitation and cause gusty winds and dry lightning to be possible. - Strong ridging aloft will produce a dry and hot period for Sunday through Tuesday, with the primary challenges being the above normal heat and fire weather conditions. Isolated high based thunderstorms will be possible on Wednesday over and near the mountains, with coverage slowly increasing Thursday and Friday, along with an attendant slow cooling of daytime maximum temperatures. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 220 AM MDT Sat Jul 11 2026 The upper level ridge becomes a little more stout as it builds over us. The subsident flow from the upper level ridge will start to mix in dry air from the upper levels of the atmosphere and bring it down to the surface. This will also reduce the number of clouds in the sky raising the surface heating efficiency in our region. Even in southerly flow this may help over perform what the models think the high temperature for the day is supposed to be. So today will be fairly sunny with temperatures in the 90's with some of our northern counties possibly reaching 100 today. Humidity levels will also drop in the afternoon to around 15 percent or lower in Southeast Wyoming and around 20-25 percent for the Nebraska Panhandle. With the winds expected to be light and no showers forecasted, the environment is in an elevated fire state for today. However, it is interesting to note that the NAM NEST, FV3, and the ARW want to populate some light showers between 18z and 21z today. The NAM Nest has some sort of stationary boundary that isn't seen in the surface observations with easterly winds forming an upslope convergence boundary to produce some showers along Platte and Goshen County. The NBM had random 12 pops around that time with QPF outputs near a tenth forming little bullseyes across Goshen and Sioux county. Those were taken out as the surface will be too dry and there really wont be much to lift but we shall see if I'm wrong or not today. For Sunday, the fire watch was upgraded to a red flag warning that now lasts through Monday evening. A system will be moving across Canada compressing against our ridge to give the intermountain west a boost in gradient winds that looks to be strong enough for the Red Flag criteria with gusts above 25 mph. The Heat advisory was extended as well until 06z Wednesday or midnight Tuesday as the ridge remains in place over us for that long to give our region temperatures near or exceeds 100 degrees during the day and we dont really drop below 70 at night until 3-4am looking at the models. So this weekend is the perfect time to go out and enjoy the local festivities, however just remember to stay hydrated and have a couple snacks to prevent heat injuries while doing them. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 1230 PM MDT Fri Jul 10 2026 Sunday through Thursday...Primary challenges will be the heat and fire weather conditions. A 5980 dekameter 500 mb ridge lies over Wyoming Sunday morning, moving to the northern Great Planes Monday morning, and then remains entrenched across the northern Rockies and northern Great Planes through the period. Models suggesting typical monsoonal moisture creeping into our counties Wednesday through Friday with weak perturbations and some mid level moisture to spark isolated to widely scattered thunderstorms over and near the Snowy and Sierra Madre Ranges, as well as the Southern Laramie Range and Laramie Valley from Wednesday through Friday, with coverage of storms slowly increasing through that aforementioned period. Ridging aloft dominates our region, with quite dry air at low and mid levels, accompanied by typically toasty 700 mb temperatures, thus chances for late day showers and thunderstorms will be nearly nil and non existent, and dry weather will prevail through Tuesday. The 700 mb temperatures will yield maximum temperatures mainly in the 90 to 105 degree range. Weak perturbations and a slight increase in mid level monsoonal moisture may spark isolated high based thunderstorms on Wednesday, and moreso on Thursday and Friday, again dependent on how much mid level monsoonal moisture advects into our CWA, County Warning Area. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1048 PM MDT Fri Jul 10 2026 Quiet conditions are expected overnight at most terminals with light winds and clearing skies. A low-level jet could develop in the vicinity of KCDR, leading to 25 kt wind gusts tonight into early Saturday morning. Benign conditions continue into the day Saturday with sunny skies and VFR conditions. Winds will be fairly light across Wyoming terminals during the day, but gusts of 20 to 25 kts can be expected at Nebraska terminals during the afternoon hours. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Fire Weather Watch from noon MDT today through Sunday morning for WYZ417-418-423-430>433. Heat Advisory from noon today to midnight MDT Tuesday night for WYZ101-102-107-108-118-119. Red Flag Warning from noon Sunday to 8 PM MDT Monday for WYZ417>420-423-427-430>433. NE...Fire Weather Watch from noon MDT today through Sunday morning for NEZ434. Heat Advisory from noon today to midnight MDT Tuesday night for NEZ002-003-019>021-054-055-095-096. Red Flag Warning from noon Sunday to 8 PM MDT Monday for NEZ434. && $$ SHORT TERM...MM LONG TERM...RUBIN AVIATION...SF ####018008238#### FXPQ50 PGUM 110823 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 623 PM ChST Sat Jul 11 2026 .Marianas Synopsis... Visible satellite imagery depicts mostly cloudy skies and scattered showers over the Marianas with some isolated pockets of convection. Buoy and altimetry data support combined seas between 8 to 10 feet. && .Discussion... The leading edge of a trough extending northward from Invest 97W (west of Chuuk) is within proximity of the eastern coastal waters of the Marianas. Gentle to moderate winds have gradually shifted from the north to the northeast throughout today, which will become easterly on Sunday as the trough moves through the region the next couple of days. Increased shower coverage and isolated thunderstorms are expected overnight and will peak on Sunday with locally heavy showers possible accompanied with gusty winds. Then, southerly to southwesterly flow may follow, possibly maintaining speeds of 10 to 15 mph with scattered showers and isolated thunderstorms at least until next weekend. && .Marine... The primary westerly swell from distant Typhoon Bavi (09W) has remained large enough to induce combined seas hazardous to small craft, hazardous surf, and dangerous rip currents along north, south, and west facing reefs. Altimetry and buoy data indicated sea heights between 8 to 10 ft along western coastal waters, so the Small Craft Advisory was continued at least through early Sunday morning. The westerly swell is expected to relax over the next several days, but the long period will keep surf along west facing reefs elevated, potentially prolonging the high risk of rip currents beyond Sunday morning. However, surf along north and south facing reefs may drop below hazardous criteria sometime overnight, so marine conditions will be reassessed by 4 AM ChST Sunday. Next week, the primary swell direction may shift out of the southwest, briefly strengthening, then maintaining swell heights at least until next weekend. && .Tropical Systems... It's a pretty interesting pattern that we have today, involving a pair of Invests, a Near-Equatorial Trough (NET), and unusually strong cross-equatorial flow of 15 to 25 knots. Invest 97W continues to remain as a "Sub-Low" rating from the Joint Typhoon Warning Center (JTWC), as does Invest 98W. 97W is currently located near Satawal in eastern Yap State (near 7.8N 148.1E), and 98 being east-southeast of Majuro near 5.8N 174.0E. Regarding Invest 97W, the models continue to remain in total disarray regarding if it'll head towards Yap and then off to the northwest, or will it pass between Guam and Yap doing much the same, or will a new circulation form east of Guam and absorb some of the energy. The next question being, will it develop into a tropical depression or stronger? Given the MJO (Madden-Julian Oscillation) is not in phase with this wave, significant development is not expected. Instead, it'll likely continue to move northwest, passing near or over Guam as a modestly organized LLCC (Low-Level Circulation Center), while remaining below tropical depression strength. Then it'll continue northwest on it's journey. Aside from increasing shower and thunderstorm potential, residents in Guam and the CNMI can rest easy, this system isn't expected to be more than a "rain-maker" for us, with perhaps an isolated gust or two near 30 mph. Farther east-southeast, we have Invest 98W by Majuro. This system looks less organized than its predecessor, although abundant cloud cover and an indifferent scatterometer pass yield little assistance in determining LLCC organization/potential. With that said, it's more convectively active than 97W. This may be an artifact of "better preconditioning" from the cross-equatorial flow" The models in general show this feature moving west-northwest for the next 72 to 96 hours, before perhaps making more of a west. How much this system will organize remains uncertain, as does it's related potential strength. With that said, folks in the Marianas, Yap State, Chuuk, and all of Eastern Micronesia should continue to monitor these circulations. At the very least, they'll bring periods of increased rainfall potential, some of which could be locally heavy. This will be aided by increased surface convergence near the NET, near the peripheries of the Invests, and due to the cross-equatorial flow feeding into these systems. It should be of note, the cross-equatorial flow is a "wild card in the forecast equation", as the models struggle to depict how much influence this will have on either systems development. Thus, to reintegrate, stay informed with forecast updates, but remain calm as this does not look like a Sinlaku or Bavi-type event. && .Eastern Micronesia... The cross-equatorial flow discussed in the tropical section above has really taken hold today, with 15 to 25 knots of south to southwest winds observed in the scatterometer data and as easily seen in visible imagery. The interaction of this flow with the pair of Invests and the NET described above is allowing for fairly expansive convective development. Most of this has been moderately heavy but nothing too extreme based on cloud top temperatures and satellite morphology (trends). With that in mind, shower coverage was increased into the numerous categorical range (numerous to widespread), but shorter in duration sufficiently enough to preclude locally heavy rainfall wording in the forecast. It remains unclear how long this cross-equatorial flow will persist or remain this strong, so for now the higher shower coverage was mainly confined to the next three days, dropping to scattered shower coverage after that. As for marine conditions, seas will remain in the 4 to 6 foot range. Light to gentle winds will predominately prevail at Kosrae and Majuro, while Pohnpei sees moderate to fresh winds through Sunday decreasing into the light to gentle range thereafter. && .Western Micronesia... The High Surf Advisory has been extended through Sunday afternoon at Yap, while the Small Craft Advisory was allowed to expire for Yap. For Palau and Yap, a weakening ridge remains over the area. This ridge is expected to give way to showers produced by the outer reaches of Invest 97W. Model guidance is pretty adamant about categorical showers moving in to Yap and Palau, however, showers produced by 97W have been lack-luster. This leaves a bit of uncertainty in the intensity of these showers. To reflect this uncertainty, showers are toned down to high-end scattered over the weekend. A brief lull is possible for the beginning of the work week before the next round of showers could move in for the middle of the week. For Chuuk, with 97W and the Near-Equatorial Trough near by, periods of numerous showers are expected through the rest of the weekend. Heavy showers are unlikely during this time. Benign weather may return as early as Monday night and remain through the middle of the week. Altimetry shows combined seas near Palau around 5 to 7 feet, near Yap Proper around 6 to 8, and near Chuuk around 7 to 9 feet. Rumung buoy in Yap shows heights of about 6 feet at 13 second period. Winds are expected to remain around light to moderate. Overall, choppy seas are expected through out the region but below Small Craft Advisory thresholds. Seas are anticipated to gradually fall by a foot or two over the next week. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...High Rip Current Risk through late tonight for GUZ001. High Surf Advisory until 4 AM ChST Sunday for GUZ001. MP...High Rip Current Risk through late tonight for MPZ001>003. High Surf Advisory until 4 AM ChST Sunday for MPZ001>003. Marianas Waters...Small Craft Advisory until 4 AM ChST Sunday for PMZ151>154. && $$ Marianas: Mesa East Micronesia/Tropical Systems: Doll West Micronesia: Bowsher ####018005808#### FXUS65 KCYS 110823 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 223 AM MDT Sat Jul 11 2026 .KEY MESSAGES... - Strong ridging aloft will produce a dry and hot period for Sunday through Tuesday, with the primary challenges being the above normal heat and fire weather conditions. Isolated high based thunderstorms will be possible on Wednesday over and near the mountains, with coverage slowly increasing Thursday and Friday, along with an attendant slow cooling of daytime maximum temperatures. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 220 AM MDT Sat Jul 11 2026 The upper level ridge becomes a little more stout as it builds over us. The subsident flow from the upper level ridge will start to mix in dry air from the upper levels of the atmosphere and bring it down to the surface. This will also reduce the number of clouds in the sky raising the surface heating efficiency in our region. Even in southerly flow this may help over perform what the models think the high temperature for the day is supposed to be. So today will be fairly sunny with temperatures in the 90's with some of our northern counties possibly reaching 100 today. Humidity levels will also drop in the afternoon to around 15 percent or lower in Southeast Wyoming and around 20-25 percent for the Nebraska Panhandle. With the winds expected to be light and no showers forecasted, the environment is in an elevated fire state for today. However, it is interesting to note that the NAM NEST, FV3, and the ARW want to populate some light showers between 18z and 21z today. The NAM Nest has some sort of stationary boundary that isn't seen in the surface observations with easterly winds forming an upslope convergence boundary to produce some showers along Platte and Goshen County. The NBM had random 12 pops around that time with QPF outputs near a tenth forming little bullseyes across Goshen and Sioux county. Those were taken out as the surface will be too dry and there really wont be much to lift but we shall see if I'm wrong or not today. For Sunday, the fire watch was upgraded to a red flag warning that now lasts through Monday evening. A system will be moving across Canada compressing against our ridge to give the intermountain west a boost in gradient winds that looks to be strong enough for the Red Flag criteria with gusts above 25 mph. The Heat advisory was extended as well until 06z Wednesday or midnight Tuesday as the ridge remains in place over us for that long to give our region temperatures near or exceeds 100 degrees during the day and we dont really drop below 70 at night until 3-4am looking at the models. So this weekend is the perfect time to go out and enjoy the local festivities, however just remember to stay hydrated and have a couple snacks to prevent heat injuries while doing them. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 1230 PM MDT Fri Jul 10 2026 Sunday through Thursday...Primary challenges will be the heat and fire weather conditions. A 5980 dekameter 500 mb ridge lies over Wyoming Sunday morning, moving to the northern Great Planes Monday morning, and then remains entrenched across the northern Rockies and northern Great Planes through the period. Models suggesting typical monsoonal moisture creeping into our counties Wednesday through Friday with weak perturbations and some mid level moisture to spark isolated to widely scattered thunderstorms over and near the Snowy and Sierra Madre Ranges, as well as the Southern Laramie Range and Laramie Valley from Wednesday through Friday, with coverage of storms slowly increasing through that aforementioned period. Ridging aloft dominates our region, with quite dry air at low and mid levels, accompanied by typically toasty 700 mb temperatures, thus chances for late day showers and thunderstorms will be nearly nil and non existent, and dry weather will prevail through Tuesday. The 700 mb temperatures will yield maximum temperatures mainly in the 90 to 105 degree range. Weak perturbations and a slight increase in mid level monsoonal moisture may spark isolated high based thunderstorms on Wednesday, and moreso on Thursday and Friday, again dependent on how much mid level monsoonal moisture advects into our CWA, County Warning Area. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1048 PM MDT Fri Jul 10 2026 Quiet conditions are expected overnight at most terminals with light winds and clearing skies. A low-level jet could develop in the vicinity of KCDR, leading to 25 kt wind gusts tonight into early Saturday morning. Benign conditions continue into the day Saturday with sunny skies and VFR conditions. Winds will be fairly light across Wyoming terminals during the day, but gusts of 20 to 25 kts can be expected at Nebraska terminals during the afternoon hours. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Fire Weather Watch from noon MDT today through Sunday morning for WYZ417-418-423-430>433. Heat Advisory from noon today to midnight MDT Tuesday night for WYZ101-102-107-108-118-119. Red Flag Warning from noon Sunday to 8 PM MDT Monday for WYZ417>420-423-427-430>433. NE...Fire Weather Watch from noon MDT today through Sunday morning for NEZ434. Heat Advisory from noon today to midnight MDT Tuesday night for NEZ002-003-019>021-054-055-095-096. Red Flag Warning from noon Sunday to 8 PM MDT Monday for NEZ434. && $$ SHORT TERM...MM LONG TERM...RUBIN AVIATION...SF