Warmer and more humid today and Friday; thunder chance for some

Thursday is the last full day of astronomical summer. The autumnal equinox is at 3:02 p.m. CDT on Friday, but it’ll feel very summery.

Temperature trends

Thursday afternoon highs will be mainly in the 70s over northern Minnesota, with 80s in about the southern half of our favorite state.

On Friday, central and southern Minnesota are expected to top 90 degrees:

Dew point temperature will rise noticeably Thursday afternoon, and dew points will be in the 70s in central and southern Minnesota Friday afternoon:

Bottom line: Friday will be steamy for central and southern Minnesota, even though astronomical autumn starts Friday afternoon.

On Saturday, highs will range from the 60s in far northwestern Minnesota to the 80s in the southeast:

Similar highs are on tap for Sunday, but some spots in the far northwest might only reach the 50s:

Looking ahead to next week, Twin Cities highs are expected to be in the 70s on Monday, then in the 60s on Tuesday and Wednesday.

Rain chances

A few scattered showers and thunderstorms could develop over Minnesota late Thursday afternoon and Thursday evening, and continue into the overnight hours.

On Friday and Friday night, the northwestern half of Minnesota has the best chance of showers and thunderstorms.

A front will remain parked over Minnesota through most of this weekend, with the most concentrated showers and thunderstorms from southwestern Minnesota through central and northeastern Minnesota.

The National Oceanic and Atmospheric Administration’s Global Forecast System model shows the potential weekend rain pattern:

NOAA GFS model rainfall rate Friday evening through Sunday evening, via tropical tidbits

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

Severe weather outlook

The Storm Prediction Center of the National Weather Service shows a marginal risk of severe weather Thursday and Thursday night over northern and central Minnesota:

NWS Storm Prediction Center

Marginal risk means that an isolated severe thunderstorm is possible.

Most of Thursday will be dry, with the chance of a thunderstorm mainly from late Thursday afternoon into the evening and overnight hours.

The Storm Prediction Center shows a slight risk of severe weather Friday and Friday night from west-central Minnesota into north-central Minnesota:

NWS Storm Prediction Center

Slight risk means that scattered thunderstorms are possible.

Tropical update

Infrared to visible loop of Maria Thursday morning. National Oceanic and Atmospheric Administration

The Thursday morning update from the National Hurricane Center shows Hurricane Maria was just off the northeast coast of the Dominican Republic:

National Hurricane Center

Maria’s max winds were 115 mph, and she was moving northwestward.

Hurricane warnings are in effect for the Dominican Republic from Cabo Engano to Puerto Plata, and for the Turks and Caicos Islands and the Southeastern Bahamas.

Here’s the NHC Thursday morning Hurricane Maria update:

BULLETIN
Hurricane Maria Intermediate Advisory Number 21A
NWS National Hurricane Center Miami FL AL152017
800 AM AST Thu Sep 21 2017

…MARIA’S LARGE EYE PASSING OFFSHORE OF THE NORTHEASTERN COAST OF
THE DOMINICAN REPUBLIC…

 

SUMMARY OF 800 AM AST…1200 UTC…INFORMATION
———————————————-
LOCATION…19.9N 68.7W
ABOUT 95 MI…150 KM NNW OF PUNTA CANA DOMINICAN REPUBLIC
ABOUT 190 MI…305 KM SE OF GRAND TURK ISLAND
MAXIMUM SUSTAINED WINDS…115 MPH…185 KM/H
PRESENT MOVEMENT…NW OR 315 DEGREES AT 9 MPH…15 KM/H
MINIMUM CENTRAL PRESSURE…959 MB…28.32 INCHES

 

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

The government of the Bahamas has issued a Tropical Storm Watch for
the central Bahamas.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for…
* Dominican Republic from Cabo Engano to Puerto Plata
* Turks and Caicos Islands and the Southeastern Bahamas

A Tropical Storm Warning is in effect for…
* Dominican Republic west of Puerto Plata to the northern border of
the Dominican Republic and Haiti
* Dominican Republic west of Cabo Engano to Punta Palenque

A Hurricane Watch is in effect for…
* Dominican Republic from Isla Saona to Cabo Engano

A Tropical Storm Watch is in effect for…
* Central Bahamas

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life and
property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

A Hurricane Watch means that hurricane conditions are possible
within the watch area, in this case within the next 12 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in Hispaniola and the Bahamas should monitor the
progress of Maria.

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 the
United States, please monitor products issued by your national
meteorological service.

 

DISCUSSION AND 48-HOUR OUTLOOK
——————————
At 800 AM AST (1200 UTC), the large eye of Hurricane Maria was
located near latitude 19.9 North, longitude 68.7 West. Maria is
moving toward the northwest near 9 mph (15 km/h), and this general
motion is expected through tonight. A turn toward the
north-northwest is forecast on Friday. On the forecast track, the
eye of Hurricane Maria will continue to pass offshore of the
northeastern coast of the Dominican Republic today. Maria should
then move near the Turks and Caicos Islands and the southeastern
Bahamas tonight and Friday.

Maximum sustained winds are near 115 mph (185 km/h) with higher
gusts. Maria is a category 3 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Some strengthening is possible during the
next day or so.

Hurricane-force winds extend outward up to 60 miles (95 km) from
the center, and tropical-storm-force winds extend outward up to 150
miles (240 km).

The estimated minimum central pressure is 959 mb (28.32 inches).

 

HAZARDS AFFECTING LAND
———————-
WIND: Strong gusty winds are still occurring over portions of
Puerto Rico, but should continue to gradually subside this morning.
Tropical storm or hurricane conditions are continuing across
portions of the warning areas in the Dominican Republic. Hurricane
conditions are expected to begin in portions of the Turks and Caicos
Islands and the southeastern Bahamas tonight, with tropical storm
conditions beginning in these areas later today. Tropical storm
conditions are possible in the central Bahamas beginning late
Friday.

STORM SURGE: Water levels in Puerto Rico should continue receding
during the next few hours.

A dangerous storm surge accompanied by large and destructive waves
will raise water levels by as much as 4 to 6 feet above normal tide
levels in the hurricane warning area in the Dominican Republic, and
1 to 3 ft elsewhere along the northern coasts of the Dominican
Republic and Haiti.

A dangerous storm surge accompanied by large and destructive waves
will raise water levels by as much as 9 to 12 feet above normal
tide levels within the hurricane warning area of the southeastern
Bahamas and the Turks and Caicos Islands.

RAINFALL: Maria is expected to produce the following rainfall
accumulations through Saturday:

Puerto Rico…additional 4 to 8 inches, isolated maximum storm total
amounts 35 inches.
U.S. and British Virgin Islands…additional 2 to 4 inches.
Northern and eastern Dominican Republic, Turks and Caicos, and
Mayaguana in southeast Bahamas…8 to 16 inches, isolated 20 inches.
Inagua Islands, Crooked Island, and rest of southeast Bahamas…4 to
8 inches.
Northern Haiti…2 to 4 inches.

Rainfall on these islands will continue to cause life-threatening
flash floods and mudslides.

SURF: Swells generated by Maria are still affecting the Leeward
Islands, Puerto Rico, and the Virgin Islands. These swells are
also affecting the northern coast of Hispaniola, the Turks and
Caicos Islands, and should begin in the Southeastern Bahamas later
today. These swells are likely to cause life-threatening surf and
rip current conditions. Please consult products from your local
weather office.

 

NEXT ADVISORY
————-
Next complete advisory at 1100 AM AST.

According to the National Hurricane Center, Tropical Storm Jose is stationary in the Atlantic:

National Hurricane Center

Jose was 150 miles southeast of Nantucket, Massachusetts Thursday morning, with max sustained winds of 60 mph.

Here’s the NHC Thursday morning update on Jose:

BULLETIN
Tropical Storm Jose Intermediate Advisory Number 64A
NWS National Hurricane Center Miami FL AL122017
800 AM AST Thu Sep 21 2017

…TROPICAL STORM CONDITIONS OCCURRING OVER PORTIONS OF
SOUTHEASTERN NEW ENGLAND…
…HIGH SURF AND RIP CURRENTS EXPECTED TO CONTINUE ON THE EAST
COAST OF THE UNITED STATES…

 

SUMMARY OF 800 AM AST…1200 UTC…INFORMATION
———————————————-
LOCATION…39.6N 68.1W
ABOUT 150 MI…240 KM SE OF NANTUCKET MASSACHUSETTS
MAXIMUM SUSTAINED WINDS…60 MPH…95 KM/H
PRESENT MOVEMENT…STATIONARY
MINIMUM CENTRAL PRESSURE…982 MB…29.00 INCHES

 

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

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for…
* Woods Hole to Sagamore Beach, including Cape Cod
* Block Island
* Martha’s Vineyard
* Nantucket

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 48-HOUR OUTLOOK
——————————
At 800 AM AST (1200 UTC), the center of Tropical Storm Jose was
located near latitude 39.6 North, longitude 68.1 West. Jose is
stationary, and the system is expected to continue to meander off
the coast of southeast New England for the next several days.

Maximum sustained winds remain near 60 mph (95 km/h) with higher
gusts. Gradual weakening is forecast during the next couple of
days, and Jose is forecast to become post-tropical on Friday.

Jose is a large system. Tropical-storm-force winds extend
outward up to 230 miles (370 km) from the center. A gust to 48 mph
(78 km/h) was recently reported at the Nantucket Airport. An
unofficial observing site in Vineyard Haven on Martha’s Vineyard
recently reported a sustained wind of 39 mph (63 km/h) with a gust
to 52 mph (83 km/h).

The minimum central pressure recently reported by an Air Force
reconnaissance aircraft is 982 mb (29.00 inches).

 

HAZARDS AFFECTING LAND
———————-
WIND: Tropical storm conditions are expected to occur in the
warning area today.

SURF: Swells generated by Jose are affecting Bermuda and much of
the U.S. east coast and will likely cause dangerous surf and rip
current conditions during the next few days. For more information,
please consult products from your local weather office.

RAINFALL: Jose is expected to produce the following additional
rainfall accumulations through Friday:

Martha’s Vineyard and Cape Cod…additional 1 to 2 inches.
Nantucket…additional 2 to 4 inches.

 

NEXT ADVISORY
————-
Next complete advisory at 1100 AM AST.

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.