<message to="mfannin2@nwws-oi.weather.gov/jaxl#a20cc823625d586c32d7eedaf70a07b1" type="groupchat" from="nwws@conference.nwws-oi.weather.gov/nwws-oi"><body>KCYS issues Area Forecast Discussion (AFD) valid 2024-06-01T02:11:00Z</body><html xmlns="http://jabber.org/protocol/xhtml-im"><body xmlns="http://www.w3.org/1999/xhtml">KCYS issues Area Forecast Discussion (AFD) valid 2024-06-01T02:11:00Z</body></html><x xmlns="nwws-oi" id="nwws_processor.3611" issue="2024-06-01T02:11:00Z" ttaaii="FXUS65" cccc="KCYS" awipsid="AFDCYS"><![CDATA[ 208 FXUS65 KCYS 010211 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 811 PM MDT Fri May 31 2024 .UPDATE... Issued at 800 PM MDT Fri May 31 2024 Frontal boundary currently stationary across the Laramie Range this evening with westerly winds at Laramie and south to southeast winds reported about 10 miles east of the highest foothills of the Laramie Range. Do not expect this front to eject eastward until early Saturday morning. With increasing east to southeast winds over the high plains and current obs showing increasing dewpoints (moisture advection), added patchy fog to the forecast. Do not think the fog will be dense, but ceiling of 300 to 800 feet is close enough for fog...especially along the elevated ridges. Fog or low stratus is forecast to dissipate quickly Saturday morning as the front lifts northeast as a warm front...this will set the stage for isolated or widely scattered severe thunderstorms east of I-25 Saturday afternoon and evening. && .KEY MESSAGES... - Daily chances for isolated to scattered showers and thunderstorms continue through the weekend. A few storms may have the potential to become strong to severe each day. - Warm and dry weather is expected most of next week, aside from an uncertain potential for a cold front which could bring some shower/storm activity on Tuesday or Wednesday. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 150 PM MDT Fri May 31 2024 Surface high pressure located over southwest South Dakota this afternoon creating an easterly surface wind component over the eastern half of the CWA. Stratus this morning east of the Laramie Range has been persistent and slow to break up in southeast low level upslope flow. 1PM temperatures remain quite cool with upper 50s in the Panhandle and southeast Wyoming plains east of the Laramie Range. Cheyenne finally broke out maybe an hour or so ago. Latest SPC Mesoanalyst page showing quite a bit on CIN across the Panhandle into southeast Wyoming in these southeast winds and stratus. Where skies are clearing...current SBCAPE has risen to 500-1000 J/KG across western Laramie County into southern Platte County. Lack of surface heating from the low clouds shows SBCAPE not rising too much through the afternoon with low level CIN returning by 00Z. Given the persistent stratus...do not think we will see much this afternoon convection wise. Another late night show possible as a dry cold front drops into the southeast Wyoming plains as parent upper shortwave tracks across eastern Montana and western SOuth Dakota. HRRR and RAP simulated radar showing convection developing across the northern Nebraska Panhandle towards 06Z tonight that could become strong to severe for a time through 11Z. Really questionable on severe convection Saturday as GFS showing really dry air pushing into the Panhandle. Dryline on the GFS pushes through the Panhandle by 21Z Saturday. So its not matching up well with peak heating. Confidence not high on severe convection Saturday afternoon/evening and the SPC Slight Risk area. Guess it depends on timing of the dryline moving eastward. A slower timing would improve severe convection chances. Later shifts will need to watch the timing of the dryline push. As for Sunday...it all depends on the timing of the dryline push on Saturday. Could see a dry forecast for Sunday...but for now...kept chance PoPs (30-40 percent) for Sunday afternoon. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 150 PM MDT Fri May 31 2024 The long term looks relatively uneventful with mostly dry and mild conditions expected throughout next week. Quasi-zonal flow for the first half of the work week will lead to breezy and windy conditions across much of the CWA. A strong shortwave trough passing just to the north of the CWA on Tuesday will lead to the greatest potential for high winds across the southeast Wyoming wind prones. The GFS has 700 mb wind speeds of 50 to 60 kts, and elevated CAG to CPR 700 mb height gradients. In-house guidance is also pinging the potential for high winds around the wind prones. Cannot rule out some slight precipitation chances with the passage of this shortwave either. Cooler temperatures can also be expected on Tuesday as the shortwave ushers in slightly cooler 700 mb air. By Wednesday, ridging begins to build over western CONUS, leading to a warmer and drier airmass infiltrating the CWA. Temperatures through Friday will gradually increase, with most locations seeing highs in the 80s by Friday. Minimal precipitation chances are expected during this time frame as subsidence keeps conditions dry. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 505 PM MDT Fri May 31 2024 Another round of showers and thunderstorms are possible near the KCDR terminal, but the primary aviation concern will be low ceilings and potentially some fog across the Nebraska terminals and KCYS. Could see MVFR to near-IFR conditions at KCYS, with similar conditions at KBFF, KCDR, and KSNY. KAIA looks to drop into the IFR to near-LIFR conditions overnight as ceilings crash to 700ft and visibility is reduced to 2SM. Fog and low stratus should move out of the terminals by 14Z and VFR conditions will return. Some sites could see an oscillation between SCT010 and BKN010 leading to frequent changes between good conditions and poor conditions. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...TJT SHORT TERM...GCC LONG TERM...SF AVIATION...AM ]]></x><stanza-id xmlns="urn:xmpp:sid:0" id="bf891f3c-f570-46e0-9eaa-190480c67b01" by="nwws@conference.nwws-oi.weather.gov"/></message>