ACUS01 KWNS 281630 SWODY1 SPC AC 281628 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Sep 28 2026 Valid 281630Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms may occur this afternoon and evening across parts of western/northern South Dakota and vicinity. ...Northern Plains... Clouds and elevated thunderstorms remain prevalent late this morning across parts of the Dakotas. A narrow window for strong to locally severe thunderstorms may exist this afternoon/evening across parts of western/northern SD and vicinity as convection develops along/east of a weak surface trough. While lapse rates aloft should remain modest, filtered daytime heating with surface temperatures reaching the mid/upper 70s will probably be sufficient for robust thunderstorm development. A belt of modestly enhanced southwesterly mid-level flow will extend across the northern Rockies/Plains today, and 30-40 kt of deep-layer shear should support updraft organization. Current expectations are for thunderstorms to initially form near the Black Hills by 20-22Z, and then spread east-northeastward along/near a surface front through the evening. The stronger cells may be capable of producing isolated hail and gusty winds, before convection tends to become elevated with eastward extent across northern SD/southern ND by late evening. ...Lower Colorado River Valley... Showers and thunderstorms should develop this afternoon as an anomalously moist low-level airmass spreads northward ahead of a mid-level shortwave trough forecast to move from CA/NV to the lower CO River Valley through the period. Cloudiness and weak mid-level lapse rates should limit instability through early afternoon, before cloud cover gradually diminishes through early evening. A stronger thunderstorm or two may occur parts of interior southern CA/northwest AZ/southern NV, but the overall risk for severe hail/wind appears too limited to include any probabilities for this region at this time. ..Gleason/Chalmers.. 09/28/2026 $$ SOVD83 KWNB 281600 RRX KKYY 28096 1612/ 737201 076266 88871 83099 20001 32079 99999 44072= KKYY 28096 1612/ 738963 076448 88871 83099 20001 32076 41318 99999 44063= KKYY 28096 1612/ 738556 076415 88871 83099 20001 32081 41593 99999 44062= KKYY 28096 1612/ 737552 076251 88871 83099 20001 32063 42044 99999 44058= KKYY 28096 1612/ 738033 076336 88871 83099 20001 32029 41716 99999 44042= SNVD15 KWNB 281600 RRR BBXX 44014 28161 99366 70748 46/// ///// 1//// 30126 91620 22200 00189 10602 70009= FPNE40 NFFN 281200 NIUE WEATHER BULLETIN ISSUED FROM NWFC NADI SEP 281217 UTC. A STRONG WIND REMAINS IN FORCE FOR LAND AREAS OF NIUE. SITUATION: A HIGH PRESSURE SYSTEM TO THE FAR SOUTHWEST OF NIUE CONTINUES TO DIRECT FRESH TO STRONG SOUTHEAST WINDS OVER THE ISLAND. FORECAST TO MIDNIGHT TONIGHT FOR NIUE: EXPECT SOUTHEAST WINDS WITH WIND SPEEDS UP TO 45 KM/HR. ROUGH SEAS. MODERATE SOUTHERLY SWELLS. FINE APART FROM BRIEF SHOWERS. COOL AT NIGHT. FURTHER OUTLOOK: STRONG SOUTHEAST WINDS WITH WIND SPEEDS UP TO 45 KM/HR AND GUST UP TO 55 KM/HR. FINE APART FROM BRIEF SHOWERS. COOL AT NIGHT. MARINE WEATHER BULLETIN FOR NIUE A STRONG WIND WARNING REMAINS IN FORCE OVER NIUE WATERS. FORECAST TO MIDNIGHT TONIGHT FOR ALL NIUE WATERS: SOUTHEAST WINDS 20 TO 25 KNOTS. ROUGH SEAS. MODERATE SOUTHERLY SWELLS. FURTHER OUTLOOK: SOUTHEAST WINDS 20 TO 25 KNOTS, GUSTING UP TO 30 KNOTS. ROUGH SEAS TO VERY ROUGH. MODERATE SOUTHERLY SWELLS. SOVD83 KWNB 281500 RRX KKYY 28096 1528/ 743071 070868 88872 83099 20001 31574 43036 99999 44074= SOVD83 KWNB 281500 RRX KKYY 28096 1545/ 743071 070868 88872 83099 20001 31578 43041 99999 44074= SOVD83 KWNB 281500 RRX KKYY 28096 1511/ 743071 070868 88872 83099 20001 31574 43038 99999 44074= SOVD83 KWNB 281500 RRX KKYY 28096 1556/ 743071 070868 88872 83099 20001 31580 43043 99999 44074= SOVD83 KWNB 281600 RRX KKYY 28096 1600/ 743715 069355 88872 83099 20001 31303 43247 20002 31305 99999 44032= KKYY 28096 1600/ 744055 068996 88872 83099 20001 31402 43157 20002 31403 99999 44033= FAUS24 KZMA 281631 ZMA4 CWA 281631 ZMA CWA 402 VALID UNTIL 281830 FROM 30ESE ZQA-90ESE ZQA-110SE ZQA-80SSE ZQA-30ESE ZQA AREA TS MOV FM 23015KT. TOPS EST TO FL430. EXP LTL CHG THRU 1830Z. =