Area Forecast Discussion
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
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615 FXUS63 KOAX 240757 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 257 AM CDT Tue Sep 24 2024 .KEY MESSAGES... - Seasonable temperatures through the work/school week with low chance (20-30%) of showers this morning; otherwise mostly dry conditions through Thursday. - A complex weather pattern is in store going into and lasting through the weekend, with increasing confidence in drier conditions and temperatures in the upper 70s to low 80s. && .DISCUSSION... Issued at 253 AM CDT Tue Sep 24 2024 Today: Water vapor imagery this morning depicts a seasonally high-amplitude ridge centered over the Pacific Coast, with a broad trough pointing southward over the Northern Plains and broad forcing ahead of it extending well into the Mid-Mississippi and Ohio River Valleys. At the surface, a cold front continues to progress southeastward, stretching from far western Minnesota to south-central Nebraska resulting in a broken band of light rain showers that have so far only mustered trace amounts of moisture. Expect this broken band of rain to continue pushing southeastward through eastern Nebraska and southwestern Iowa while staying in the ballpark of a trace in terms of additional rainfall due to the general lack of column moisture in the wake of this last weekend`s frontal passage. By 9 or 10 AM, the thicker cloud cover with the main front will be mostly clear of the area, allowing for clearing skies ahead of an afternoon cumulus field to punctuate a very pleasant day with highs in the mid-to- upper 70s. Wednesday and Beyond: As the deep trough continues pushing east of the area Wednesday, the global deterministic model solutions depict the mid/upper pattern developing a cutoff low as the southernmost lobe of 500 mb vorticity pinches off from over the Mid-Mississippi Valley. What this will mean locally is that the main ridge to the west will struggle to make too much headway into the forecast area and only slightly warmer temperatures in the upper 70s to low 80s rather than a warmer pattern will move in. Dry weather will continue as the main forcing for ascent will be located well to the southeast, while any potential wraparound moisture takes its time to kick into gear with the deepening low. Both the National Hurricane Center and model consensus have a potentially strong tropical system making landfall over the Florida Panhandle region Thursday, to the southeast of the aforementioned cutoff low. The spread that was apparent with the last couple of days` model runs in the progression of the main mid/upper pattern has decreased dramatically, with general consensus that the tropical system and the aforementioned cutoff low will merge, and generally fester over the Mid-Mississippi Valley for the weekend. We`ll continue to find ourselves on the cooler side of the broad mid/upper ridge over the western half of the CONUS (temps in the upper 70s to low 80s), and on the dry side of the pattern while the cutoff system spins to the southeast. There is still plenty of time for models to laze the deep surface system north and west enough to bring some minor moisture to southeast Nebraska and southwest Iowa, but at this moment any rainfall will be hard to come by -- especially any amounts that will make an impact. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1145 PM CDT Mon Sep 23 2024 A weak cold front will drift through the region, from northwest to southeast between 06-14Z tonight. There will be a slight chance for a few showers and perhaps an isolated rumble of thunder with the frontal passage, however the chance of these spotty showers impacting the TAF sites remains too low to include a mention at this time. In addition to the chance for rain, we will see a wind shift from southeast to northwest as the front moves through. Winds will be light through the overnight period, but are expected to increase to 10-12 kts by 14-17Z Tuesday. A few gusts near 20 kts will be possible, especially at KOFK, Tuesday afternoon. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Petersen AVIATION...KG