A hot Memorial Day; air quality alert too

It's still hot.

The high temperature at Minneapolis-St. Paul International Airport was 91 degrees Sunday afternoon. That's well above our average high of 73 degrees for this time of year.

It would have been even warmer if the early afternoon cloud deck had thinned out more quickly.

Many spots in southern Minnesota hit the upper 90s.  Madison, in west-central Minnesota, hit 102 degrees just before 6 p.m.:

I saw a 100 degree reading in Worthington.

Sunday was our fourth consecutive day with a Twin Cities high temp in the 90s.  We should reach the 90s again on Memorial Day, which will set a new Twin Cities record for consecutive May days with highs in the 90s.

New record highs on Sunday included 88 degrees in Duluth, 93 in Rochester, 95 in Eau Claire, WI and 98 in La Crosse, WI.

Temperature trends

Memorial Day highs are expected to be in the 90s in about the southern half of Minnesota, with mainly 80s in the north:

It'll be cooler near Lake Superior.  The Twin Cities metro area should reach the upper 90s, with dew point temps in the sticky 60s.

Most of Minnesota will see highs in the 80s on Tuesday, with lower 90s in the Twin Cities and southeastern Minnesota.

Metro area highs are expected to be in the mid 80s Wednesday through Friday.

Heat advisory

The NWS is continuing the heat advisory overnight and through Monday morning in the Twin Cities, with an excessive heat watch Monday afternoon.

A heat advisory runs from 1 p.m. to 7 p.m. Monday through much of the southern half of Minnesota and west-central Wisconsin:

Details of the advisory and excessive heat watch for the Twin Cities:

URGENT - WEATHER MESSAGE

National Weather Service Twin Cities/Chanhassen MN

352 PM CDT Sun May 27 2018

MNZ060>063-068>070-280500-

/O.NEW.KMPX.EH.A.0001.180528T1800Z-180529T0000Z/

/O.EXT.KMPX.HT.Y.0001.000000T0000Z-180528T1800Z/

Hennepin-Anoka-Ramsey-Washington-Carver-Scott-Dakota-

Including the cities of Minneapolis, Blaine, St Paul, Stillwater,

Chaska, Shakopee, and Hastings

352 PM CDT Sun May 27 2018

...HEAT ADVISORY NOW IN EFFECT UNTIL 1 PM CDT MONDAY...

...EXCESSIVE HEAT WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH

MONDAY EVENING...

The National Weather Service in Twin Cities/Chanhassen has issued

an Excessive Heat Watch, which is in effect from Monday afternoon

through Monday evening.

* TEMPERATURE...Mid 90s are still expected late this afternoon.

Temperatures will only cool into the low to mid 70s tonight,

especially downtown, so the Heat Advisory has been extended

through the night. Highs Monday will likely reach the upper 90s.

The humidity will also be higher than today, resulting in peak

heat indices possibly in the lower 100s by afternoon.

* IMPACTS...Heat illnesses are possible for those active

outdoors or those susceptible to heat illnesses, such as

children and the elderly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures is

expected. The combination of hot temperatures and high humidity

will combine to create a situation in which heat illnesses are

possible. Drink plenty of fluids...stay in an air-conditioned

room...stay out of the sun...and check up on relatives and

neighbors.

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 light weight and loose fitting clothing when

possible and drink plenty of water.

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.

An Excessive Heat Watch means that a prolonged period of hot

temperatures is expected. The combination of hot temperatures and

high humidity will combine to create a dangerous situation in

which heat illnesses are possible. Drink plenty of fluids...stay

in an air-conditioned room...stay out of the sun...and check up

on relatives and neighbors.

Here are some heat safety tips from NOAA:

Air quality alert

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert for the Twin Cities metro area and much of southern Minnesota:

According to the MPCA:

Air quality is expected to worsen Monday to unhealthy levels. Sunny skies, hot temperatures, and light winds will combine to cause an increase in ground level ozone. In addition, pollutants will collect along the warm front that will be located just south of the Twin Cities and contribute to increased ozone. Air Quality Index (AQI) values are expected to climb into the low 100s on Monday in the alert area. This is considered unhealthy for sensitive groups. Ozone concentrations will be the lowest in the morning hours Monday, and will gradually rise midday through the afternoon. Air quality will improve Monday early evening as thunderstorms develop in southern Minnesota and the sun lowers in the sky.

Rain opportunities

Northern Minnesota could see scattered showers and thunderstorms overnight and early Sunday morning.

Most of Minnesota will have plenty of rain-free hours on Memorial Day, but scattered showers and thunderstorms could develop in the south late in the afternoon or on the evening.

Periods of showers and thunderstorms are expected on Tuesday and Wednesday:

The National Oceanic and Atmospheric Administration’s Global Forecast System model shows the potential precipitation pattern Tuesday through Wednesday:

The color chart to the right of the loop refers to the precipitation rate (mm per hour), not to the total amount of rain.

Alberto's rain and winds

Subtropical storm Alberto continues to strengthen:

Here's an Alberto update from the National Hurricane Center:

BULLETIN

Subtropical Storm Alberto Advisory Number 10

NWS National Hurricane Center Miami FL AL012018

400 PM CDT Sun May 27 2018

...ALBERTO TURNS NORTH-NORTHWESTWARD WITH NO CHANGE IN STRENGTH...

SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION

----------------------------------------------

LOCATION...28.0N 85.2W

ABOUT 165 MI...265 KM W OF TAMPA FLORIDA

ABOUT 120 MI...190 KM S OF APALACHICOLA FLORIDA

MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H

PRESENT MOVEMENT...NNW OR 345 DEGREES AT 12 MPH...19 KM/H

MINIMUM CENTRAL PRESSURE...994 MB...29.36 INCHES

WATCHES AND WARNINGS

--------------------

CHANGES WITH THIS ADVISORY:

The Tropical Storm Warning along the west coast of Florida has been

discontinued south of the Anclote River.

The Storm Surge Watch has been discontinued along the northern Gulf

Coast west of Navarre, Florida.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Watch is in effect for...

* Crystal River to Navarre Florida

A Tropical Storm Warning is in effect for...

* Anclote River to the Mississippi/Alabama border

A Storm Surge Watch means there is a possibility of life-

threatening inundation, from rising water moving inland from the

coastline, in the indicated locations. For a depiction of areas at

risk, please see the National Weather Service Storm Surge

Watch/Warning Graphic, available at hurricanes.gov.

A Tropical Storm Warning means that tropical storm conditions are

expected somewhere within the warning area.

For storm information specific to your area, including possible

inland watches and warnings, please monitor products issued by your

local National Weather Service forecast office.

DISCUSSION AND OUTLOOK

----------------------

At 400 PM CDT (2100 UTC), the center of Subtropical Storm Alberto

was located near latitude 28.0 North, longitude 85.2 West. The

storm is moving toward the north-northwest near 12 mph (19 km/h). A

north-northwest motion with some decrease in forward speed is

expected tonight. A north-northwestward to northward motion is

expected Monday through Wednesday. On the forecast track, the

center of Alberto will move over the northern Gulf of Mexico tonight

and approach the northern Gulf Coast in the warning area on Monday.

Heavy rainfall and tropical storm conditions will likely reach the

northern Gulf Coast well before the arrival of the center of

Alberto. Alberto is expected to move inland into the Tennessee

Valley on Tuesday and Wednesday.

Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.

Little change in strength is forecast before Alberto reaches the

northern Gulf Coast. Steady weakening is expected after landfall,

and Alberto is forecast to become a tropical depression Monday night

or Tuesday.

Winds of 40 mph extend outward up to 115 miles (185 km) from the

center.

The estimated minimum central pressure is 994 mb (29.36 inches).

HAZARDS AFFECTING LAND

----------------------

RAINFALL: Alberto is expected to produce the following rain

accumulations through Tuesday:

Central Cuba...Additional 5 to 10 inches, isolated storm-totals of

20-25 inches.

The Florida panhandle into much of Alabama and western Georgia...4

to 8 inches, isolated 12 inches.

The Florida Keys and south Florida...Additional 3 to 6 inches,

isolated storm totals of 10 inches.

Rest of the Florida peninsula...1 to 4 inches.

Rest of the Southeast and Tennessee Valley into the lower mid

Atlantic from Tennessee east through the Carolinas...2 to 6 inches.

Rains in Cuba could produce life-threatening flash floods and

mudslides. Flooding and flash flooding are possible in the

southeast United States, including Florida.

WIND: Tropical storm conditions will spread northward within

the warning area tonight and continue through Monday.

STORM SURGE: The combination of storm surge and the tide will cause

normally dry areas near the coast to be flooded by rising waters

moving inland from the shoreline. The water could reach the

following heights above ground somewhere in the indicated

areas if the peak surge occurs at the time of high tide...

Crystal River to Navarre Florida...2 to 4 ft

The deepest water will occur along the immediate coast. Surge-

related flooding depends on the relative timing of the surge

and the tidal cycle, and can vary greatly over short distances. For

information specific to your area, please see products issued by

your local National Weather Service forecast office.

TORNADOES: Isolated tornadoes are possible through tonight across

the central and northern Florida peninsula.

SURF: Swells generated by Alberto will affect the eastern and

northern Gulf Coast through Tuesday. These swells are likely

to cause life-threatening surf and rip current conditions. For more

information, consult products from your local weather office.

The center of Alberto could make landfall along the panhandle of Florida on Monday:

Heavy rainfall totals are expected in many gulf coast areas over the next few days:

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:49 a.m. Thursdays and Fridays, and at 7:35 a.m., 9:35 a.m. and 4:35 p.m. each Saturday and Sunday.