
T.D. Two Likely to Strengthen to Tropical Storm Today
Tropical Depression Two continues to slowly churn in the northeastern Gulf, likely becoming the Atlantic’s second named storm later today.
# HEADLINE -------------------- EXTREME HEAT WARNING NOW IN EFFECT FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING # DETAILS -------------------- WHAT Dangerously hot conditions with heat index values up to 107 expected. WHERE Portions of northwest and west central Iowa, northeast Nebraska, and southeast South Dakota. WHEN From 11 AM this morning to 8 PM CDT this evening. IMPACTS Heat related illnesses increase significantly during extreme heat and high humidity events. ISSUED AT Monday, July 20, 2026 at 8:00 AM CDT ISSUED BY National Weather Service Sioux Falls SD HEADER URGENT - WEATHER MESSAGE # PRECAUTIONARY/PREPAREDNESS ACTIONS -------------------- Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1. # AREAS AFFECTED -------------------- Union, Buena Vista, Cherokee, Clay, Dakota, Dixon, Ida, Plymouth, Woodbury Including the cities of Cherokee, Jefferson, Vermillion, Allen, Ida Grove, Beresford, Sioux City, Ponca, Battle Creek, North Sioux City, Holstein, Elk Point, Storm Lake, Alcester, Wakefield, South Sioux City, and Le Mars
There is a Slight Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN IOWA AND NORTHWESTERN ILLINOIS ACROSS WISCONSIN INTO WESTERN UPPER MICHIGAN THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL NORTH CAROLINA SUMMARY Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon into late evening. A few strong-intense tornadoes, swaths of damaging winds, and isolated very large hail will all be possible. Isolated damaging gusts may also occur over parts North Carolina this afternoon. Upper Midwest through tonight A midlevel shortwave trough is cresting the ridge and will turn southeastward today while moving over the upper MS Valley, as an associated cold front likewise moves southeastward into Upper MI, WI and IA. Earlier storms in Upper MI have weakened, while a cluster is ongoing in eastern IA. Destabilization will occur in the wake of the eastern IA storms as a reservoir of low-mid 70s boundary-layer dewpoints spreads northeastward from IA/southern MN into WI and western Upper MI. The low-level moistening will occur beneath a plume of midlevel lapse rates greater than 8 C/km and in tandem with surface heating in cloud breaks, all of which will drive MLCAPE in excess of 3000 J/kg. As is typical with lingering morning convection, there is some uncertainty regarding the specific locations of afternoon storm development in its wake. Wind profiles will favor supercells as the initial storm mode this afternoon along and just ahead of the cold front, given very long hodographs oriented largely orthogonal to the front. Low-level shear/hodograph curvature will also be substantial, which combined with the moist boundary layer, steep lapse rates and large buoyancy will support the potential for a few strong-intense tornadoes. Very large hail will be possible with the more discrete supercells, while significant severe outflow gusts will be possible with any clustering of storms later this afternoon/evening. Initial supercells will likely evolve into a cluster or two by early tonight while spreading southeastward across eastern IA, northern IL, northwest IN and Lower MI with a continued threat for occasional wind damage and isolated large hail. Central NC area this afternoon/evening Thunderstorm development is expected again this afternoon along a stalled front/differential heating zone across NC, to the west of the more persistent cloud cover in far eastern NC. NC remains near the south edge of the midlevel westerlies, with mid 70s boundary-layer dewpoints coincident with temperatures at or above 90 F contributing to MLCAPE in excess of 2000 J/kg. A few damaging downbursts will be possible with precipitation-loaded downdrafts in an environment with steepening low-level lapse rates. FL Big Bend today Tropical Depression #2 is forecast to drift slowly westward across the northeast Gulf through tomorrow and become a tropical storm. Though deep-layer wind profiles are not particularly favorable in the northeast quadrant of the cyclone, where winds aloft are from the northeast, there is just enough low-level shear to support weakly rotating storms in the outer convective bands. An isolated tornado/waterspout or two may occur today in coastal areas of the FL Big Bend.












