Area Forecast Discussion
Issued by NWS Hastings, NE
Issued by NWS Hastings, NE
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797 FXUS63 KGID 222127 AFDGID Area Forecast Discussion National Weather Service Hastings NE 427 PM CDT Wed May 22 2024 .KEY MESSAGES... - Can`t rule out an isolated shower/storm late tonight-early Thursday morning across southern portions of the forecast area (20 percent chance)...but most locations should have a quiet evening/night. - Threat for thunderstorms increases late in the day Thursday- Thursday night (70-90 percent chances), with the potential for severe weather...most of the forecast area is included in the SPC Day 2 Enhanced Risk area. - A few isolated storms are possible mid-late afternoon, but by far the better chances will be mid evening on into the overnight hours...mainly between 8PM-3AM. Wind gusts of at least 70 MPH looks to be the primary threat, but large hail up to the size of golf balls and brief spin-ups are not out of the question. - Following a dry Friday, chances for thunderstorms return Sat- Mon, with the best chances looking to be Saturday evening through Sunday evening. Details regarding the potential for strong/severe storms (mainly Saturday) are uncertain at this time. && .DISCUSSION... Issued at 421 PM CDT Wed May 22 2024 Currently through tonight... Been a pleasant day across the forecast area today...upper air and satellite data show mainly westerly flow in place across the Central Plains, set up under weak ridging between areas of low pressure spinning over the western Great Lakes/Ontario and over the Pacific NW. Satellite imagery also shows outside of a bit of fair weather CU over northeastern portions of the area, skies are sunny. At the surface, high pressure extending through KS into MO, keeping winds westerly across the forecast area...generally around 10 MPH, but there have been occasional gusts closer to 20 MPH. A few locations may end up a couple degrees short of expectations, but overall things have worked out, with 3PM temps in the mid 60s to low 70s. Looking at this evening into tonight, for most locations, it should be a quiet period. Exception may be across southern areas (near/south of the NE/KS state line), where some isolated precipitation may develop, and have 20 percent chances going in the forecast. Several models show at least spotty activity sliding east after midnight through early-mid morning, driven by subtle warm air advection/mid-level wave. Could end up being little more than a few sprinkles...but some models do have the potential for a hundred j/kg of CAPE to build north, so a few thunderstorms (non-severe) are not out of the question. Winds turn to the south with time tonight, as surface low pressure moves onto the High Plains. Should see a few more clouds passing through, overnight lows tonight are forecast to drop into the low 50s. Thursday and Friday... Next widespread chance for thunderstorms and potential for strong/severe storms returns to the area Thursday-Thursday night. At 12Z Thursday, models show that upper level low currently over the Pac NW having shifted east into the ID/WY border region...and by 00Z shifts into the WY/SD border area, with a southward extending trough axis. At the surface, during the daytime hours winds across the forecast area look to remain southerly...as low pressure remains over the High Plains. A sharper dryline is expected to develop over western KS/southwestern NE, with cold front getting pushed southeast by the upper level system. Where exactly this cold front ends up by late afternoon-early evening still has some uncertainties...ranging anywhere from the western Sandhills to knocking on the door of our western counties. The increased southerly low level flow (wind speeds of 20-25 MPH and higher gusts possible) pulls in warmer and more moist air into the forecast are through the day...with forecast highs climbing into the upper 70s to mid 80s. Currently expecting much of, if not all, of the 12-00Z time frame on Thursday to be dry...but do have a 20 percent chance of storms during the 21-00Z time frame, as some models show the potential for isolated activity to develop in or near southeastern portions of the forecast area (most models keep this activity to our east). The better, more widespread chances will come during the evening-overnight hours. Thunderstorms are expected to develop along that approaching surface cold front to our northwest, then transition into a more solid line/MCS and push southeast through our forecast area. Models showing MUCAPE values of at least 2500 j/kg ahead of this complex to tap into, deeper layer shear of 30-40kts possible, better upper forcing and an increasing low-level jet (40+kts)...threat for severe weather is a concern...and much of the area is included in the SPC Day 2 Enhanced Risk area. Wind gusts of at least 70 MPH look to be the main concern with this complex...but large hail and brief spin- ups are not out of the question. And while this activity will also have the potential for torrential rainfall rates, it should be progressive enough to keep spots from accumulating significant rainfall totals. Main time frame for severe weather looking to generally be in the 8PM - 3AM. Forecast for Friday and Friday night remain dry, as we sit under generally zonal flow in the wake of this upper level trough axis. Breezy northwesterly winds behind the cold front passage are expected to continue on into the day on Friday...tapering off closer to 10-15 MPH by late afternoon. Should see plenty of sun during the day, with partly cloudy skies overnight...afternoon highs are forecast to range from the mid 60s in the north to lower 70s in the south. Memorial Day Holiday weekend and on... Each day of the upcoming holiday weekend and Memorial Day itself continue to have precipitation chances in the forecast...with the best chances currently Saturday evening through Sunday evening (40-60 percent chances at various times). Models showing continued generally zonal flow in the upper levels, with a couple of shortwave disturbances pushing through the Central Plains, driving those weekend precip chances. Chances on Monday/Memorial Day are a little more iffy...weekend chances look more widespread across the area, Monday may just be clipping north-northeastern portions. Confidence in overall timing/location of these systems isn`t overly high. Details about potential for severe weather, which would mainly be focused on Saturday, are not clear-cut...much will depend on how much instability can work its way back north into the forecast area (more solidly southerly flow doesn`t look to return until Saturday morning). The slower the return, the less opportunity for notable instability to be in place. Will just how the next couple days trend. Forecast dries back out for Tuesday...and is currently dry for Wednesday as well, but again, will see how things trend with Wed. As far as temperatures go, not looking at any big swings either way Saturday through Wednesday. Forecast currently has mainly 70s Sat-Mon (confidence isn`t overly high in that due to the precip chances)...with mid 70s-low 80s for Tuesday and low-mid 80s for Wed. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1120 AM CDT Wed May 22 2024 High presure over SE NE will slide to the ESE during the period. The winds will start off westerly, but will become southerly this evening. An area of low pressure moving out of the Rockies tomorrow will tighten the gradient to where the winds are forecast to gust into the low 30s by the end of the TAF period. VFR expected through the period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...ADP AVIATION...Beda