Steamy weekend; Saturday afternoon heat advisory for the Twin Cities metro area

No, your calendar isn’t broken.

This really is September 15, even though it will feel like July this afternoon.

Saturday afternoon highs are expected to reach the upper 80s to lower 90s in about the southern half of Minnesota.

Dew points will be in the upper 60s to lower 70s in southern and central Minnesota, so it’ll feel steamy.

The National Weather Service has issued a heat advisory for Saturday afternoon in the Twin Cities metro area:

Details of the heat advisory:

URGENT – WEATHER MESSAGE
National Weather Service Twin Cities/Chanhassen MN
956 AM CDT Sat Sep 15 2018

MNZ060-062-152300-
/O.CON.KMPX.HT.Y.0013.180915T1800Z-180915T2300Z/
Hennepin-Ramsey-
Including the cities of Minneapolis and St Paul
956 AM CDT Sat Sep 15 2018

…HEAT ADVISORY REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO
6 PM CDT THIS EVENING…

* TEMPERATURE…Heat indices of 95 to 100 degrees.

* 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 which could lead to heat illnesses. 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
drink plenty of water.

Temperature trends

We’ve already talked about the Saturday afternoon heat in  southern and central Minnesota.

Northern Minnesota will have Saturday afternoon highs in the 70s, with some 60s in the  northeast.

Most of Minnesota will see Sunday highs in the 80s:

The Twin Cities metro area could reach 90 degrees.

Our average high temp this time of year is only 72 degrees in the Twin Cities metro area.

Twin Cities metro area highs are projected to reach the lower 80s Monday, followed by lower 70s Tuesday and around 70 on Wednesday and Thursday. We might only reach the upper 60s next Friday.

Record dew points? 

We might be flirting with record high dew point temperatures in the Twin Cities metro area at some point this Saturday afternoon or evening.

Here are some September dew point records for the Twin Cities, courtesy of the Minnesota State Climatology Office:

Minnesota State Climatology Office

You might remember the record high dew points of September 21 and 22 of 2017!

Minnesota rain chances

Far northern Minnesota will have a chance of scattered showers and thunderstorms late Saturday afternoon and Saturday evening.

Updated weather information can be heard on the Minnesota Public Radio Network, and updates are also posted on the MPR News live weather blog.

Much of Sunday is expected to be rain-free, with a chance of scattered showers and thunderstorms Sunday evening in the north.

The shower and thunderstorm chance spreads across more of Minnesota Sunday night and on Monday.

The National Oceanic and Atmospheric Administration’s North American Mesoscale forecast model shows the potential rain pattern Sunday evening through Monday afternoon:

NOAA NAM simulated radar from Sunday evening through Monday afternoon, via tropicaltidbits

The color chart to the right of the loop refers to the strength of the signal that returns to the radar, not to the amount of rain.

Off and on showers and thunderstorms are expected on Wednesday and Thursday.

Fall colors

Even though astronomical autumn doesn’t arrive until September 22, fall colors are appearing in parts of Minnesota.

The fall color report from the Minnesota Department of Natural Resources shows significant fall color in parts of northwestern Minnesota:

Minnesota DNR

Tropical storm Florence

Tropical storm Florence continues to bring torrential rains to parts of the Carolinas.

Florence is moving very slowly, westward at only 2 mph, so the torrential rains are far from over, and recovery will take a while.

Humans and wildlife all have to find higher ground until the waters receed:

An impressive radar loop of Florence since Thursday, and a comparison to Hurricane Harvey of 2017:

Record-breaking rainfall totals have already been reached in parts of North Carolina:

Here’s the Saturday morning update on Florence, from the National Hurricane Center:

BULLETIN
Tropical Storm Florence Advisory Number  65
NWS National Hurricane Center Miami FL       AL062018
1100 AM EDT Sat Sep 15 2018

…FLORENCE CRAWLING WESTWARD ACROSS EASTERN SOUTH CAROLINA…
…HEAVY RAINS AND CATASTROPHIC FLOODING CONTINUE ACROSS PORTIONS
OF NORTH CAROLINA AND SOUTH CAROLINA…

SUMMARY OF 1100 AM EDT…1500 UTC…INFORMATION
———————————————–
LOCATION…33.6N 79.6W
ABOUT 40 MI…65 KM W OF MYRTLE BEACH SOUTH CAROLINA
ABOUT 40 MI…65 KM S OF FLORENCE SOUTH CAROLINA
MAXIMUM SUSTAINED WINDS…45 MPH…75 KM/H
PRESENT MOVEMENT…W OR 270 DEGREES AT 2 MPH…4 KM/H
MINIMUM CENTRAL PRESSURE…995 MB…29.38 INCHES

WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:

The Tropical Storm Warning has been discontinued south of South
Santee River and north of Cape Lookout.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for…
* Myrtle Beach South Carolina to Ocracoke Inlet North Carolina
* Pamlico Sound, including the Neuse and Pamlico Rivers

A Tropical Storm Warning is in effect for…
* South Santee River South Carolina to Cape Lookout North Carolina
* Pamlico Sound

Interests elsewhere in the southeastern and mid-Atlantic states
should monitor the progress of Florence.

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 1100 AM EDT (1500 UTC), the center of Tropical Storm Florence was
located near latitude 33.6 North, longitude 79.6 West. Florence is
moving slowly toward the west near 2 mph (4 km/h) and a slow
westward motion is expected to continue through today. A turn toward
the west-northwest and northwest is expected on Sunday. Florence is
forecast to turn northward through the Ohio Valley by Monday.

Radar data and surface observations indicate that maximum sustained
winds have decreased to near 45 mph (75 km/h) with higher gusts,
mainly to the east of the center in heavy rainbands over water.
Gradual weakening is forecast while Florence moves farther inland
during the next couple of days, and it is expected to weaken to a
tropical depression by tonight.

Tropical-storm-force winds extend outward up to 150 miles (240 km)
from the center.  A sustained wind of 38 mph (61 km/h) with a gust
to 45 mph (72 km/h) was recently reported at the Johnny Mercer Pier
in Wrightsville Beach, North Carolina. A sustained wind of 38 mph
(61 km/h) with a gust to 48 mph (78 km/h) was recently reported by
a NOAA C-MAN station at Cape Lookout, North Carolina.

The estimated minimum central pressure based on nearby surface
observations is 995 mb (29.38 inches).

HAZARDS AFFECTING LAND
———————-
STORM SURGE:  The combination of a dangerous 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 has the
potential to reach the following heights above ground…

The Neuse, Pamlico, Pungo, and Bay Rivers…3-5 ft
Cape Lookout NC to Cape Fear NC…3-5 ft
Ocracoke Inlet NC to Cape Lookout NC…2-4 ft
Cape Fear NC to Myrtle Beach SC…2-4 ft

The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
destructive waves.  Surge-related flooding can vary greatly over
short distances.  For information specific to your area, please see
products issued by your local National Weather Service forecast
office.

RAINFALL: Florence is expected to produce heavy and excessive
rainfall in the following areas…

Southern and central portions of North Carolina into far northeast
South Carolina…an additional 15 to 20 inches, with storm totals
between 30 and 40 inches along the North Carolina coastal areas
south of Cape Hatteras. This rainfall will continue to produce
catastrophic flash flooding and prolonged significant river
flooding.

Remainder of northern South Carolina into western North Carolina and
southwest Virginia…5 to 10 inches, isolated 15 inches.

West-central Virginia into far eastern West Virginia, north of
Roanoke and west of Charlottesville, 3 to 6 inches, isolated 8
inches.  These rainfall amounts will result in life-threatening
flash flooding and river flooding, along with an elevated risk for
landslides.

A preliminary report from a cooperative observer near Swansboro,
North Carolina, indicates that more than 30 inches of rain has
fallen so far. In Newport, North Carolina, more than 24 inches of
rainfall has been measured.

WIND:  Tropical storm conditions will continue today in portions of
the warning area along the coast and also over large portions of
eastern North Carolina and extreme eastern South Carolina, with
tropical-storm-force wind gusts spreading well inland.

TORNADOES:  A few tornadoes are possible in southeastern North
Carolina northeastern South Carolina today through tonight.

SURF:  Swells generated by Florence are affecting Bermuda, portions
of the U.S. East Coast, and the northwestern and central Bahamas.
These swells are likely to cause life-threatening surf and rip
current conditions.  Please consult products from your local weather
office.

Some areas could see additional rainfall amounts of 10 to 20 inches:

NOAA/National Weather Service    Potential additional rainfall from Florence Saturday morning through Wednesday night

The NAM forecast model shows that the torrential rain in the Carolinas will taper off late on Sunday:

NOAA NAM simulated radar from Saturday morning through Sunday evening, via tropicaltidbits

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.