Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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987 FXUS63 KOAX 141710 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 1210 PM CDT Sun Jul 14 2024 .KEY MESSAGES... - Early morning storms entering northeast Nebraska may pack a windy punch with gusts of up to 70 mph possible. - Dangerous heat is expected for much of the area this weekend into Monday, with heat index readings of 100 to 110+ degrees likely. Sunday and Monday will be the hottest days. - More widespread storm chances (20-40%) arrive Monday night and linger through Wednesday. && .DISCUSSION... Issued at 254 AM CDT Sun Jul 14 2024 Today and Monday: Of immediate concern this morning is the quick southeastern propagation of what will likely be categorized as a derecho, moving across south-central South Dakota towards northeast Nebraska. Despite an increasingly ragged look to the MCS, gusts of over 70 mph have been reported by mesonet stations within the last 20 minutes with the HRRR brining 60 to 70 mph wind gusts across Knox and Cedar counties from 4 to 6 AM, potentially with a gust front well out ahead of the main storms. As it sits right now, those two counties are the primary concern and hold the highest chances of seeing severe gusts while areas to the south and east will likely only see gusts of 40 to 55 mph with the leftovers of the system through mid- morning. Of secondary but more widespread concern is dangerous heat this afternoon and for parts of the area Monday. The forecast in place reflects ensemble consensus for high temperatures both days while we`ve continued to push higher dewpoints, and as a result locations within the issued Excessive Heat Warning are expected to see heat indices of 110 to 115 degrees while the rest of the area falls under a Heat Advisory. Confidence in the heat has continued to be steadied by the impending thermal ridge moving into the area, while a leftover boundary or two that linger today in southeast Nebraska may help temperatures and dewpoints over-perform where it festers. For Monday, the expected front moving south into the area will bring some relief to northeast Nebraska, but may make areas to the south and east of it feel as bad if not worse as moisture is pooled and compressional heating increases ahead of its slow movement. Storms will also be possible Monday, but those chances continue to only graze northeast Nebraska and stay relegated to Iowa and South Dakota primarily. Tuesday and Beyond: We`ll see the patter shift for the rest of the week shift from the oppressive ridge from the weekend/Monday into north/northwesterly flow that will keep the heat off to the western third of the CONUS. The retrograding ridge will amplify through the rest of the work week and lob shortwaves at the forecast area, with no end in sight through the first 200 hours of the global deterministic runs. We`ll enjoy cooler temps and recurring rain chances for an overall pleasant part of the summer forecast period. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1207 PM CDT Sun Jul 14 2024 VFR conditions are forecast to remain through the TAF period. Light southerly surface winds become southeasterly at times. A 15% chance of scattered storms at OFK has not been included in this TAF. Those chances peak after midnight tonight. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Heat Advisory until 8 PM CDT this evening for NEZ011-012- 015>018-030>034-042>045-050-065-078-088. Heat Advisory from noon to 8 PM CDT Monday for NEZ015-033-034- 042>045-050-065-078-088. Excessive Heat Warning until 8 PM CDT Monday for NEZ051>053- 066>068-089>093. IA...Heat Advisory until 8 PM CDT this evening for IAZ043-055-056. Heat Advisory from noon to 8 PM CDT Monday for IAZ043-055-056. Excessive Heat Warning until 8 PM CDT Monday for IAZ069-079- 080-090-091. && $$ DISCUSSION...Petersen AVIATION...Nicolaisen