ACUS01 KWNS 171232 SWODY1 SPC AC 171231 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0731 AM CDT Fri Jul 17 2026 Valid 171300Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE NORTHERN ROCKIES AND HIGH PLAINS...UPPER GREAT LAKES...AND OHIO VALLEY INTO THE SOUTHEAST... ...SUMMARY... Strong to potentially severe storms are possible today across parts of western Montana and northern Idaho, and also across parts of the Upper Midwest and northern Great Lakes. More isolated strong to severe storms with damaging gusts are possible over parts of the Ohio Valley into parts of the Southeast. ...Northern Rockies and adjacent High Plains... To the east of an upper low near the WA/Vancouver vicinity, an upper ridge with a plume of monsoonal moisture will extend northward from the Great Basin into the northern Rockies and adjacent High Plains. Orographic lift and heating will promote the development of scattered thunderstorms this afternoon. Steepened low-level lapse rates will potentially yield storms capable of isolated severe gusts beginning this afternoon and continuing into the mid-late evening. Isolated large hail may occur with the stronger thunderstorm cores, especially over northwest MT where 0-6 km shear will be 25-35 kt. ...Upper Midwest and northern Great Lakes... A cluster of weak thunderstorms over the MN Arrowhead will likely move southeast this morning ahead of an amplifying upper trough forecast to move from northern SK to the Upper Peninsula of MI during the period. A cold front associated with the upper wave will push southeastward across the Upper Midwest and provide a focus for thunderstorms later this afternoon and evening. A warm frontal zone draped across the northern Great Lakes will advance northeastward as a low over western ON moves eastward into central ON by early evening. Forecast model guidance shows moderate buoyancy developing today within a belt of 25-40 kt west-northwesterly 500-mb flow. As a result, a few of the stronger thunderstorms will probably evolve into supercells and organized multicell clusters. Isolated large hail and damaging gusts are the primary hazards, although a brief tornado risk may also develop in the areas surrounding Lake Superior. One or more clusters of strong to severe storms may persist into the overnight along the warm front. However, confidence in this scenario is lower owing to the prior convection and uncertainties of diurnal development along the cold front. Still, a strengthening wind field and ample moisture could support a risk for damaging winds into northern Lower MI overnight. ...OH Valley to the southern Appalachians and FL... A moist and diurnally destabilizing airmass will support scattered to numerous storms developing by the mid afternoon. Some of the stronger water-loaded downdrafts will potentially be capable of 50-60 mph gusts and isolated wind damage. ...West-central TX... A weak mid- to upper-level low over west TX will move little during the day while a warm/moist conveyor persists across southern into central parts of TX. An ongoing thunderstorm cluster will likely continue across the Concho Valley aided in part by a convectively augmented zone of low-level warm-air advection. Despite very moist low levels and some enlargement of the low-level hodograph per KSJT and KDFX VAD data, weak flow in the mid levels will likely promote enough convective outflow to limit storm organization (i.e., transient storm-scale cyclonic shear) and favor a heavy rain threat. ..Smith.. 07/17/2026 $$ SMIN05 DEMS 171200 AAXX 17124 43086 21597 80000 10290 20266 39854 40028 70262 8487/ 333 10316 58004 6998/= 43128 21496 72703 10290 20230 39452 40044 70552 83570 333 10313 56690 58006 6991/ 83615 86360= 43150 21596 82302 10290 20262 39968 40028 75065 8352/ 222// 20000 333 10323 5659/ 58004 6001/ 83620 88458= 43189 32597 80000 10316 20257 30030 40039 8387/ 333 10345 58006= 43198 22396 72712 10244 20199 39259 40073 85731 333 10266 56699 58006 6991/ 83707 84612 85358= 43213 21596 72705 10298 20234 39738 40048 70252 82878 333 10344 58001 6990/= 43226 21396 82703 10282 20251 30019 40048 70262 8663/ 333 10289 5669/ 58003 6046/= 43233 32497 62715 10260 20198 39276 40083 84632 333 10299 56699 58010= 43237 21497 72903 10336 20208 39660 40039 70252 83771 333 10368 56699 58002 6990/ 81710 83615 85360= 43245 32597 62502 10370 20226 30010 40036 82531 333 10372 59002= 43279 21496 81406 10292 20238 30041 40058 71796 8497/ 333 10383 57932 57982 58011 6991/ 84616 81925 85458= 43284 21296 82303 10268 20242 39976 40091 70265 8597/ 333 10270 56599 57912 58004 6005/ 82705 83612 81925 88458= 43295 21496 72302 10218 20212 39078 48487 75065 83531 333 10286 56599 58009 6004/ 83612 85358= 43311 32597 52715 10300 20267 40090 85800 333 10315 58000 82620 84825= 43314 22596 60000 10296 20248 40097 82431 333 10308 58005 6991/= 43321 31496 72318 10274 20208 39634 40075 70522 82531 333 10308 58005 82612 86358= 43329 21597 71802 10264 20261 30038 40051 70262 83531 333 10380 58001 6003/= 43344 31596 62715 10360 20175 39960 40057 70522 83831 333 10381 58009 81620 83825 85360= 43346 32597 72010 10314 20281 30048 40056 83531 333 10375 58006 83620 85360= 43353 21496 60903 10268 20242 40102 71021 83530 333 10290 56790 58005 6016/ 83614 85358= 43369 32597 22701 10314 20264 40107 82500 333 10330 58003 82620= 43371 32497 53203 10298 20250 30029 40101 83431 333 10322 56699 58004 83614= 43185 NIL= 43201 NIL= SMIN05 DEMS 171200 AAXX 17123 43185 32597 82902 10326 20246 30029 40032 8257/ 333 10353 59002 82620 85360= 43201 32497 72309 10276 20179 39340 40050 84530 333 10314 58002 84612 86358= SMGY01 SYCJ 171200 AAXX 17121 81001 01461 60304 10282 20261 30150 40156 60023 705// 85802 333 10305 20261 31024 55074 56209 57821 59002 70043 84817= SOVD83 KWNB 171200 RRX KKYY 17076 1208/ 732803 079624 88872 83099 20000 32883 43547 99999 41029= KKYY 17076 1208/ 732279 080406 88872 83099 20000 32992 43028 99999 41033= KKYY 17076 1208/ 734144 077718 88872 83099 20000 32843 43582 99999 41038= KKYY 17076 1208/ 733988 077362 88872 83099 20000 32821 43640 99999 41037= KKYY 17076 1208/ 734207 076949 88872 83099 20000 3//// 43645 99999 41064= KKYY 17076 1208/ 733837 078477 88872 83099 20000 32921 43091 99999 41024= SMCH03 SCSC 171200 RRD AAXX 17124 85585 13/// /2603 10114 20104 39955 49991 60051 333 20097 70063=