Area Forecast Discussion
Issued by NWS Hastings, NE
Issued by NWS Hastings, NE
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343 FXUS63 KGID 182112 AFDGID Area Forecast Discussion National Weather Service Hastings NE 412 PM CDT Wed Sep 18 2024 .KEY MESSAGES... - There could be a few (<20% coverage) thunderstorms mainly east of Hwy 281 this evening (5-11PM). A marginally severe storm is possible (5%). - Warm and dry most areas Thursday and Friday with highs still in the mid to upper 80s. - Showers and thunderstorms move into the region Friday night and especially Saturday into Sunday with widespread rainfall amounts over 1 inch. - Cooler next week with highs only in the 60s for many areas Sunday through Tuesday. && .DISCUSSION... Issued at 326 PM CDT Wed Sep 18 2024 This Evening into Tonight... We have a large upper level trough across the western United States with two 500 mb low centers. The first upper low is well to our north over Montana/North Dakota with an associated surface front extending from the Dakotas south into Nebraska and Kansas. This is really more of a dry line across our area with better moisture to the east and dry high plains air to the west. The 2nd upper low is just about to come ashore over California and will be our weekend storm system. The track of this first system well to our north (North Dakota) is not providing us with much forcing and thus any showers and thunderstorms within the moist sector will be rather isolated. However, the SPC marginal risk does highlight a valid risk for the possibility of a few severe thunderstorms given MLCAPE values inching up over 1500 J/KG and 0-6 km shear values of around 30-35 KTS. Most convective models indicate that any thunderstorms would likely be rather isolated so again are expecting most locations should remain dry tonight. The best chances for catching one of those isolated storms will be east of Highway 281. Thursday and Friday... Drier air will push in from the west on Thursday behind the departing first wave with northwesterly surface winds. Therefore, dry and warm weather with highs in the mid to upper 80s are expected on Thursday. The next upper low will slowly be tracking east across southern California on Friday with return southerly flow starting to take hold across the southern and central plains ahead of this next system. We will see rising dew points, but any rainfall should likely hold off until late evening or overnight beginning first in Kansas and then working north through the Friday late night hours. Saturday and Sunday... This appears to finally be the big rain that so many have been waiting for, just too bad that it`s on a weekend. The latest 12Z ECMWF ensemble average indicates over 1 inch of precipitation for our entire forecast area with a 2 inch average across some of our eastern counties. The GFS is also bullish with precipitation this weekend. The brunt of the precipitation will be Saturday afternoon through Sunday morning, but light precipitation could linger through much of Sunday. There does not appear to be much instability with this system so severe weather is not much of a threat at this point in time. Can not rule out localized flooding if we see some localized higher amounts over 3 inches, but it has also been very dry lately. Temperatures will start to fall on Sunday on the back side of this next system with northwestern areas likely only in the 60s. Monday and Tuesday... We should dry back out and become more fall like with most highs only in the 60s to around 70. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1228 PM CDT Wed Sep 18 2024 For KGRI/KEAR Airports: Breezy south southwest winds gusting to between 20 and 24 kts this afternoon will quickly die down to less than 10 kts and become southeasterly this evening around dusk. A frontal boundary will slide through around dawn resulting in a northwesterly wind tomorrow morning. Low clouds are the main concern for the first few hours this afternoon as we could see periods of MVFR ceilings, especially at KEAR. The low clouds will eventually clear out, but probably not until around sunset. There is a very small possibility of patchy fog around dawn tomorrow, but too low of a probability to include in the TAF at this point in time. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Wesely AVIATION...Wesely