Excessive heat warning 1 p.m. to 9 p.m. Saturday; cooler Sunday

The average Twin Cities high temperature is 80 degrees this time of year. Metro area highs are forecast to reach the 90s Saturday afternoon.

Much of Minnesota and western Wisconsin will have Saturday highs in the 90s, with some 80s in north-central and northeastern Minnesota. Dew points are forecast to reach the steamy 70s Saturday afternoon in parts of central and southern Minnesota and in portions of west-central Wisconsin.

The combination of moist air and hot temperatures will generate heat index values over 100 degrees in many locations Saturday afternoon/early Saturday evening.

Excessive heat warnings and heat advisories in many areas

The National Weather Service has issued an excessive heat warning from 1 p.m. to 9 p.m. Saturday from south-central Minnesota through the Twin Cities metro area and into several adjacent counties:

A heat advisory (orange) covers many additional counties from 1 p.m. to 9 p.m. Saturday.

Here are details of the excessive heat warning:

URGENT - WEATHER MESSAGE National Weather Service Twin Cities/Chanhassen MN 611 AM CDT Sat Aug 19 2023 MNZ051>053-059>063-065>070-073>077-082>084-091-092-WIZ023-191900- /O.CON.KMPX.EH.W.0002.230819T1800Z-230820T0200Z/ Sherburne-Isanti-Chisago-Wright-Hennepin-Anoka-Ramsey-Washington- Renville-McLeod-Sibley-Carver-Scott-Dakota-Redwood-Brown-Nicollet- Le Sueur-Rice-Watonwan-Blue Earth-Waseca-Martin-Faribault- St. Croix- Including the cities of Elk River, Cambridge, Center City, Monticello, Minneapolis, Blaine, St Paul, Stillwater, Olivia, Hutchinson, Gaylord, Chanhassen, Chaska, Victoria, Shakopee, Hastings, Redwood Falls, New Ulm, St Peter, Le Sueur, Faribault, St James, Mankato, Waseca, Fairmont, Blue Earth, and Hudson 611 AM CDT Sat Aug 19 2023 ...EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO 9 PM CDT THIS EVENING... * WHAT...Dangerously hot conditions with heat index values up to 108 expected. * WHERE...Redwood Falls to Fairmont, northeast through the Twin Cities metro to Isanti and Chisago counties in Minnesota and St. Croix county in Wisconsin. * WHEN...From 1 PM this afternoon to 9 PM CDT this evening. * IMPACTS...Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. 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. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. 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.

You can hear updated weather information for Minnesota and western Wisconsin on the MPR News network.

You can check these National Weather Service sites for updated weather info: Twin Cities, Duluth, La Crosse, Wis., Sioux Falls, S.D., and Grand Forks, N.D.

Temperature trends

A cool front gradually slides through Minnesota Saturday evening and overnight. Sunday highs will be in the 70s in northern Minnesota, with mainly 80s elsewhere:

Monday highs will be in the 90s in far southern Minnesota, with 70s in the far north:

A few spots in the Twin Cities metro area could touch 90 degrees Monday afternoon.

Metro area highs are projected to reach the mid 90s on Tuesday, followed by upper 90s Wednesday then mid 90s Thursday and upper 80s on Friday.

Rain-free weekend in most areas

Saturday and most of Sunday will be rain-free in Minnesota and western Wisconsin. A few scattered showers are possible in northern Minnesota Sunday afternoon.

The National Oceanic and Atmospheric Administration’s North American Mesoscale (NAM) forecast model shows the potential rain pattern from 7 a.m. Sunday to 9 p.m. Sunday:

Hurricane Hilary

Hurricane Hilary is now a category 3 hurricane, with max sustained winds 125 mph. Hilary is headed toward the Baja California Peninsula of Mexico, and is expected to be a tropical storm when its center moves over far southern California late Sunday afternoon into Sunday night.

Here’s the forecast track, plus the cone of uncertainty, for the center of Hurricane Hilary:

Here are potential rain totals for this weekend and into the start of next week:

Rain totals between 4 inches and 6 inches are forecast for portions of southern California and southern Nevada, with isolated amounts as high as 10 inches.

This is the Saturday morning update on Hilary, from the NWS National Hurricane Center:

BULLETIN Hurricane Hilary Advisory Number 13 NWS National Hurricane Center Miami FL EP092023 900 AM MDT Sat Aug 19 2023 ...HILARY HEADED TOWARD THE CENTRAL BAJA CALIFORNIA PENINSULA... ...CATASTROPHIC AND LIFE-THREATENING FLOODING LIKELY OVER BAJA CALIFORNIA AND THE SOUTHWESTERN U.S. THROUGH MONDAY... SUMMARY OF 900 AM MDT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...22.3N 113.5W ABOUT 235 MI...375 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA ABOUT 395 MI...630 KM SSE OF PUNTA EUGENIA MEXICO MAXIMUM SUSTAINED WINDS...125 MPH...205 KM/H PRESENT MOVEMENT...NNW OR 345 DEGREES AT 16 MPH...26 KM/H MINIMUM CENTRAL PRESSURE...947 MB...27.97 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Baja California peninsula from Punta Abreojos to Cabo San Quintin A Hurricane Watch is in effect for... * Baja California peninsula north of Cabo San Quintin to Ensenada A Tropical Storm Warning is in effect for... * Baja California peninsula from Punta Abreojos southward * Baja California peninsula entire east coast * Baja California peninsula north of Cabo San Quintin to the California/Mexico border * Mainland Mexico north of Guaymas * California/Mexico border to Point Mugu * Catalina Island A Tropical Storm Watch is in effect for... * Mainland Mexico from Huatabampito to Guaymas A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere in the southwestern U.S. should monitor the progress of Hilary. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 900 AM MDT (1500 UTC), the eye of Hurricane Hilary was located near latitude 22.3 North, longitude 113.5 West. Hilary is moving toward the north-northwest near 16 mph (26 km/h). The hurricane is expected to accelerate as it moves north-northwestward to northward during the next day or two. On the forecast track, the center of Hilary will move close to the west-central coast of the Baja California Peninsula tonight and Sunday morning then move across southern California Sunday afternoon and Sunday night. Maximum sustained winds are near 125 mph (205 km/h) with higher gusts. Hilary is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Weakening is expected, but Hilary will still be a hurricane when it approaches the west coast of the Baja California Peninsula. Hilary is expected to weaken to a tropical storm before it reaches southern California. Hurricane-force winds extend outward up to 50 miles (85 km) from the center and tropical-storm-force winds extend outward up to 265 miles (425 km). A sustained wind of 44 mph (70 km/h) and a gust to 63 mph (102 km/h) were recently reported at the Cabo San Lucas Marina. The estimated minimum central pressure is 947 mb (27.97 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Hilary can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4 and WMO header WTPZ44 KNHC and on the web at hurricanes.gov/text/MIATCDEP4.shtml. RAINFALL: Hilary is expected to produce storm total rainfall amounts of 3 to 6 inches, with isolated maximum amounts up to 10 inches, across portions of the northern Baja California Peninsula through Sunday night. Flash and urban flooding, locally catastrophic, is expected, especially in the northern portions of the peninsula. Heavy rainfall is expected across the Southwestern United States, peaking late tonight through Sunday night. Rainfall amounts of 3 to 6 inches, with isolated amounts of 10 inches, are expected across portions of southern California and southern Nevada. Dangerous to catastrophic flooding is expected. Elsewhere across portions of the Western United States, rainfall totals of 1 to 3 inches are expected, resulting in localized, some significant, flash flooding. WIND: Hurricane conditions are expected within the hurricane warning area tonight and early Sunday and are possible within the hurricane watch on Sunday. Tropical storm conditions are occurring within the southern portion of the tropical storm warning area and will spread northward today and Sunday. Tropical storm conditions are possible within the tropical storm watch area through tonight. Tropical storm conditions are expected to begin in southern California Sunday afternoon. Winds could be particularly strong and gusty in and near areas of elevated terrain. Higher gusts are expected well inland near and along the forecast track. STORM SURGE: A dangerous storm surge is likely to produce coastal flooding along the western Baja California peninsula of Mexico near where the center passes the coast in areas of onshore winds, or east of the center if Hilary makes landfall. The surge will be accompanied by large and destructive waves. Coastal flooding is possible along the northern coast of the Gulf of California Sunday through early Monday. TORNADOES: A tornado or two may occur Sunday from mid-morning through the evening over parts of the lower Colorado River Valley, Mojave Desert, and Imperial Valley regions. SURF: Large swells generated by Hilary will affect portions of the Baja California Peninsula and southern California over the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.

The National Hurricane Center will issue updates on Hilary every three hours or so.

Programming note

You can hear my live weather updates on MPR News at 7:35 a.m., 9:35 a.m. and 4:39 p.m. each Saturday and Sunday.