Area Forecast Discussion
Issued by NWS Cheyenne, WY
Issued by NWS Cheyenne, WY
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633 FXUS65 KCYS 041013 AFDCYS Area Forecast Discussion National Weather Service Cheyenne WY 413 AM MDT Thu Jul 4 2024 .KEY MESSAGES... - It will be much cooler across much of the area today in the post frontal air mass. Daytime highs are expected to remain in the 70s for most locations. - Near to slightly below normal temperatures will persist over the next several days, with daily chances for isolated to widely scattered showers and thunderstorms. The threat for strong to severe thunderstorms should remain limited through at least Friday. && .SHORT TERM /THROUGH SATURDAY/... Issued at 353 AM MDT Thu Jul 4 2024 A generally quiet forecast period across southeast Wyoming & the western Nebraska Panhandle w/ just a few weak mid or upper-level disturbances embedded within northwesterly flow aloft. There may be occasional chances for showers or thunderstorms over portions of the CWA, but with the majority of the vort energy expected to be focused further to the north across the northern high plains/ western Dakotas, believe any such activity will most likely stay fairly isolated as suggested by multiple CAMs. Better convective chances may arrive Saturday afternoon as the GFS/ECM suggest the arrival of a much more defined short wave digging southeast into the Intermountain West and central Rockies by 00z Sunday. Severe potential is uncertain given a fairly persistent WNW lower-level flow pattern impacting the overall moisture quality, but overall shear profiles should support organized convection w/ increasing mid-level flow. Other than chances for showers & storms, it will be rather cool today in the wake of last night`s cold fropa with 700-mb temperatures plunging to +2 to +6 deg C. Daytime highs do not appear likely to reach 80 deg F w/ most areas likely staying in the 70s at best. While a slow warming trend may occur through Saturday, the continued influence of the larger scale broad mid/ upper level trough over the Upper Midwest & Great Lakes may keep temperatures seasonably cool with temperatures remaining near or slightly below normal through the period. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Issued at 353 AM MDT Thu Jul 4 2024 By Sunday, the CWA will be post-frontal, with below average high temperatures expected. A strong cold front will likely traverse the CWA Saturday night, dropping 700 mb temperatures on Sunday into the +8C to +4C range. This is enough to put 700 mb temperatures in the 10th percentile for NAEFS mean. These cool temperatures will limit daytime highs, with most locations not making it out of the 70s. Could also see some precipitation behind the front. A weak vort max will drop into the CWA which could trigger some weak showers in and around the high terrain. Any precipitation will be short lived as the main trough axis shifts into the central plains by Sunday night. With the trough axis gradually pushing eastward, a strong ridge will build over much of western CONUS, taking its place. This will lead to a warming trend throughout much of next week, and possibly a return to 90 degree temperatures by mid-week. During this time, the strengthening ridge will raise 500 mb heights across the CWA. This will contribute to minimal precipitation chances throughout the remainder of the long term forecast. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 930 PM MDT Wed Jul 3 2024 Northwest flow aloft prevails, as a cold front moved across the terminals overnight, ushering in a cooler airmass. Wyoming TAFS...Mostly clear skies will prevail. Winds will gust to 32 knots at Cheyenne until 08Z, then gust to 25 knots at all terminals from 15Z to 00Z. Nebraska TAFS...Scattered to broken clouds from 5000 to 8000 feet will prevail until 00Z, then clear skies will occur. Thunderstorms will be in the vicinity of Chadron and Alliance until 08Z, with ceilings near 2500 feet at times. Winds will gust to 30 knots at all terminals until 10Z, then will gust to 30 knots from 15Z to 00Z. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...CLH LONG TERM...SF AVIATION...RUBIN