Saturday, September 3, 2016

Dwindling Daylight and a Wet Week Ahead - Hermine Forecast to Become a Hurricane Again

"Climate Summary for August 2016"
No question, July and August were very wet months across the Midwest. Some spots across the state saw nearly a foot of water just during the month of August! Thanks to Mark Seeley from the MN Climate Office for this August Climate Summary below.
"Average temperatures for August from observers around the state were generally warmer than normal by 1 to 2 degrees F. The hottest periods during the month were over the first ten days, when daily Heat Index values soared above 100°F in several locations. Marshall (Lyon County) reported the highest temperature for the state on the 10th with a reading of 96°F. The lowest temperature for the month was just 37°F at International Falls on the 21st. For the first 8 months of 2016 temperatures have consistently been warmer than normal in Minnesota, placing this period as the 6th warmest in state history. The monthly total rainfall was above normal for most places in the state, except for a few isolated pockets of dryness. Many climate observers reported total monthly rainfall that was 2-3 times normal, and on a statewide basis it was the 3rd wettest August in history and wettest since 1980. For many communities it was a near-record or record wet August. Some examples include:"

11.85 inches at Red Wing
11.82 inches at Theilman (2nd wettest)
11.70 inches at Waseca (2nd wettest)
11.37 inches at Redwood Falls
9.70 inches at Chanhassen
8.96 inches at Twin Valley
8.74 inches at downtown St Paul
9.90 inches at University of Minnesota St Paul Campus
7.86 inches at Kabetogama
9.66 inches at Faribault (4th wettest)
10.21 inches at Milan (2nd wettest)
10.23 inches at Wabasha (2nd wettest)
8.36 inches at St Cloud (2nd wettest)
7.82 inches at MSP (6th wettest)

"Severe weather plagued the state during the month on several occasions: Over Augusst 10-11 severe thunderstorms moved across the west-central part of the state, bringing 4-7 inch rains to the Willmar-Olivia area, and later in the day to Wabasha County. Then over August 23-24 heavy rains fell across portions of southeastern Minnesota delivering 2-3 inch amounts, and nearly 8.5 inches south of the border in Decorah, Iowa. Then over August 27-28 heavy rains, strong winds, and some tornadoes were reported in Polk and Norman Counties of northwestern Minnesota. Some farm buildings were damaged in Norman County. With the added rainfall from August, following a wet July, this summer season (June-August) now ranks as the 4th wettest in state history, as the average 3-month rainfall for the state was just shy of 16 inches. For the Twin Cities this has been the 8th wettest summer in history with a total rainfall of 17.40 inches."
Rainfall Past 30 Days
Here's the radar estimated rainfall over the past 30 days, which suggests some fairly significant tallies across the southern half of the state and into western Wisconsin. Some spots saw nearly 12" of rain!
Rainfall Past 60 Days
The radar estimated rainfall over the past 60 days suggests several locations across the central and southern part of the state with some 12" to near 18" amounts.
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Saturday's Clouds
Saturday started off a little cloudier than expected with numerous mid/upper level clouds drifting northeast through the region. Despite seeing a little more cloud cover than initially expected, temperatures and humidity values remained quite very enjoyable. Cloud cover also thinned a bit, which made for a very enjoyable sunset!
 
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"Further Analysis from RMS on Hurricane Hermine"
"Hurricane Hermine made landfall over northwest Florida at approximately 06:00 UTC (02:00 local time) today, Friday September 2 as a Category 1 storm on the Saffir Simpson Hurricane Wind Scale, with maximum sustained wind speeds of 80 mph (130 km/hr). (1) RMS research has revealed measurable differences in vulnerability between northern Florida, where Hermine made landfall, and the rest of the state, with structures in northern Florida more vulnerable to wind. This is because there are significant differences in North Florida building stock, which is generally wooden-framed, compared with domestic properties in Central and South Florida where the use of masonry is more common. The buildings are also designed to sustain different wind speeds. Another possible reason for the higher vulnerability in northern Florida is that the area is more heavily wooded than highly developed Central Florida. Tree falls, especially from squalls in outer rainbands, can contribute to losses in areas that may not have received the highest winds from the core of the storm. For Hermine, this would be evident in the areas from Tampa northward to Perry. An analysis of wind-related claims from northern Florida related to Hurricane Ivan (2004) showed a higher severity of damage than wind-related claims from historical events which impacted central Florida."
HERMINE at Landfall
Here's a look at Hurricane Hermine just before landfall along the Florida coastline PM Thursday. Outer bands began whipping the state early Thursday, some of which produced severe weather with tornadoes and locally heavy rain. Interestingly, HERMINE was the first hurricane to affect the state since Hurricane Wilma in 2005, 11 years ago.
 
HERMINE Saturday

This was the view of Hermine early Saturday morning just off the east coast of North Carolina. Bands of heavy rain and gusty winds were still affecting parts of the Mid-Atlantic and Northeast Coat.

 
 

Hermine on Saturday

This was a view of Hermine on Saturday evening as a Post-Tropical Cyclone with sustained winds up to 70mph. Note that there was still a very apparent center of circulation, but thunderstorms surrounding the center weren't quite as impressive as they were on Thursday evening just before landfall with the Florida Panhandle.

Topical Warnings Continue
Tropical Watches and Warnings have now been extended to parts of the Northeast, including New York City, in advance of Hermine as if lifts northeast along the coast.
...TROPICAL STORM WATCH REMAINS IN EFFECT...
* LOCATIONS AFFECTED - BATTERY PARK - HARLEM - CENTRAL PARK
* WIND - LATEST LOCAL FORECAST: BELOW TROPICAL STORM FORCE WIND - PEAK WIND FORECAST: 20-30 MPH WITH GUSTS TO 50 MPH
* STORM SURGE - LATEST LOCAL FORECAST: LIFE-THREATENING STORM SURGE POSSIBLE - PEAK STORM SURGE INUNDATION: THE POTENTIAL FOR 2-4 FEET ABOVE GROUND SOMEWHERE WITHIN SURGE PRONE AREAS - WINDOW OF CONCERN: BEGINS EARLY SUNDAY AFTERNOON
* FLOODING RAIN - LATEST LOCAL FORECAST: - PEAK RAINFALL AMOUNTS: AROUND 1 INCH
 
 Intensity Model

The forecast intensity for Hermine suggests that the overall intensity will remain tropical storm strength over the next several days, however, note that a few members bring this storm back to hurricane strength! This will be something that will have to be monitored as the storm is expected to sit and wobble off the Mid-Atlantic/Northeast Coast through most of next week!


Tracking HERMINE

The forecast track from NOAA's NHC suggests that Hermine will once again turn back into a hurricane just east of the Delmarva Peninsula. This could definitely be cause for bigger concerns as folks along the coast will be susceptible to strong winds, heavier rain and coastal flooding. This will definitely have to be monitored closely over the next several days... Stay tuned!


Tropical Storm Force Winds

Here's a look at the Tropical Storm Force Wind Speed Probability through midweek next week. Note that some folks along the coast see up to a 50%-60% chance, which could make the rest of the weekend and into the first full week of September interesting!

 
 Spaghetti Plots

Spaghetti plots seem to be all over the map as Hermine moves back over the open waters of the Atlantic, however, there seems to be a bit of a consensus that the storm may sit offshore for several days before slowly drifting away late next week.

Tracking HERMINE

Here's a forecast view of Hermine midday Monday, which shows a nearly stationary storm just off the Eastern Seaboard. Interestingly, Hermine could strengthen and potentially become a hurricane again as it wobbles of the Eastern Seaboard.  Prolonged gusty winds, high coastal surf and heavy rain chances will make the rest of the Labor Day Weekend and much of next week fairly interesting.

Heavy Rain Potential

While gusty winds will persist along the East Coast, some of the heaviest rainfall is expected to be offshore up to 10" to 15"+ through Monday.

Keeping and Eye on the Atlantic
While it may not look like much yet, NOAA's NHC is keeping an eye on this particular wave of energy as it has a low chance of becoming a tropical cyclone over the next 5 days... Stay tuned!
Atlantic 5 Day Outlook
The National Hurricane Center will continue to watch the wave of energy in the Central Atlantic over the next few days. At this point, the forecast calls for less than a 40% chance of tropical formation within the next 5 days.

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Dwindling Daylight and a Wet Week Ahead
I've been so used to an early sunrise over the past few months that it came as a shock to me when it was still dark in the 5 o'clock hour this weekend. Note that we've lost nearly 2.5 hours of daylight since the Summer Solstice on June 20th and it sure is noticeable!
Daylight dwindles at its most rapid pace around the Autumnal Equinox. Unfortunately, we are losing nearly 3 minutes of daylight per day and are on pace to lose an additional hour of daylight by the first official day of Fall on September 22nd. Also note that the time change occurs only 2 months from now!
Weather conditions close to home will begin souring slowly as Hermine creates a meteorological traffic jam on the East Coast. The forecast calls for Hermine to stall offshore and strengthen into a hurricane once again, making for an ugly week from Boston to New Jersey. Meanwhile, several shots of t-storms roll through the Midwest with some forecasts calling for an additional 1 to 3 inches of rain possible through Friday.
Get ready for more skeeter swatting!
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Extended Weather Outlook
SATURDAY NIGHT: Partly cloudy and quiet. Winds: SSE 5-15. Low: 62
SUNDAY: Breezy with spotty storms late. Winds: SE 10-20. High: 80.
SUNDAY NIGHT: Mostly cloudy with scattered storms. Winds: SSE 10-15. Low: 66.
LABOR DAY: Warmer and muggier. AM puddles with storms developing late, some could be strong. Winds: S 7-12. High: 84
TUESDAY: Mostly cloudy. Scattered storms with locally heavy rainfall. Winds: WNW 7-12. Wake-up: 70. High: 80
WEDNESDAY: Unsettled. More pop-up t-showers. Winds: SE 5-10. Wake-up: 67. High: 79
THURSDAY: Lingering AM showers, more PM sun. Winds: NW 5-10. Wake-up: 65. High: 76.
FRIDAY: Sunny start, storms develop late. Winds: SSE 5. Wake-up: 60. High: 78.
SATURDAY: Slow clearing trend, cooler breeze. Winds: NW 5-10. Wake-up: 61. High: 73.
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This Day in Weather History
September 4th
1992: Early morning storms result in 3/4 to 1 3/4 inch hail in Hennepin, Dakota, Rice and Goodhue Counties.
1941: A batch of tornadoes hits Minneapolis, New Brighton, and White Bear Lake, killing six people.
1925: The third consecutive day of 95 degrees or above occurs in the Minneapolis area.
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Average High/Low for Minneapolis
September 4th
Average High: 76F (Record: 98F set in 1925)
Average Low: 58F (Record: 39F set in 1974)
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Sunrise/Sunset Times for Minneapolis
September 4th
Sunrise: 6:39am
Sunset: 7:43pm
*Daylight Lost Since Yesterday: ~3mins & 2sec
*Daylight Lost Since Summer Solstice: ~2hours and 30mins
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Moon Phase for September 4th at Midnight
4.2 Days Before First Quarter
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Weather Outlook Sunday
Temperatures and dewpoints will be a little higher on Sunday than they have been over the past few days. It won't be overly hot and humid, but you will certainly notice the increase in humidity through early next week.
Weather Outlook Sunday
Sunday will be another fairly breezy day with sustained winds in the 10 to 20mph range with a few higher gusts possible across the southwestern part of the state.
Weather Outlook Sunday
After several days of dry and mostly sunny skies, Sunday's weather looks to sour a little with a few spotty showers and storms possible across the western and northern part of the state. The best chance of showers and storms looks to arrive overnight Sunday into early Monday morning.
Simulated Radar
The simulated radar from PM Saturday to PM Monday suggests that weather conditions will sour a bit as we head into the second half of the weekend. A few spotty showers and storms may be possible on Sunday, but the best chance arrives late Sunday into early Monday and again late Monday into early Tuesday. Some of the storms could be strong to severe with locally heavy rainfall.
Rainfall Potential
Here's the rainfall potential through midday Tuesday, which suggests a fairly decent surge of moisture starting to move into the the state by late weekend/early next week Note that rainfall tallies look impressive with widespread 1" to 2"+ amounts possible.

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Thunder Threat Sunday
Sunday sees a little better chance of storms late in the day across the eastern part of North and South Dakota, some of which could be a little on the strong to possibly severe side. Whatever develops there could slide into far western Minnesota late Sunday evening.
Severe Threat Monday
As the unsettle weather nears, strong to severe storms may develop late Monday...
...CENTRAL PLAINS TO UPPER MS VALLEY... THE FORECAST SCENARIO ON DAY 3/MONDAY IS SIMILAR TO THAT OF DAY 2/SUNDAY...EXCEPT SHIFTED NORTHEAST. THE LARGE-SCALE UPPER TROUGH OVER THE WESTERN U.S. WILL NOT MOVE MUCH...BUT A SHORTWAVE IMPULSE WILL MIGRATE THROUGH STRONGER BELT OF SOUTHWESTERLY FLOW OVER THE NORTHERN PLAINS AND UPPER MIDWEST. AT THE SURFACE...A LOW WILL BE CENTERED IN THE VICINITY OF CENTRAL SD AT 12Z MONDAY AND TRACK NORTHEAST ALONG AN INVERTED SURFACE TROUGH...WHILE A COLD FRONT PUSHES EAST/SOUTHEAST ACROSS THE EASTERN DAKOTAS INTO CENTRAL NEB AND EASTERN MN BY TUESDAY MORNING. RICH BOUNDARY LAYER MOISTURE WILL OVERSPREAD THE EASTERN PLAINS AND MS VALLEY REGION ON CONTINUED SOUTHERLY LOW LEVEL FLOW. SOME UNCERTAINTY EXISTS AS CONVECTION WILL LIKELY BE ONGOING ACROSS PARTS OF ND/SD/MN MONDAY MORNING...AND CLOUD COVER COULD INHIBIT STRONGER SURFACE HEATING. HOWEVER...MOST GUIDANCE SUGGEST THERE SHOULD AT LEAST BE A NARROW...UNCAPPED AND MODERATELY UNSTABLE WARM SECTOR BY LATE AFTERNOON FROM NORTHEAST NEB/SOUTHEAST SD INTO CENTRAL MN. SIMILAR TO THE EXPECTED STORM EVOLUTION ON DAY 2...INITIAL SUPERCELLS WILL BE POSSIBLE WITH ALL SEVERE HAZARDS POSSIBLE BEFORE UPSCALE GROWTH ENSUES. THE AREA OF HIGHER SEVERE RISK MAY SHIFT SOME IN COMING OUTLOOKS AS FINER-SCALE DETAILS OF WHERE THE SURFACE TROUGH/COLD FRONT AND LOW EVENTUALLY RESIDE...AND ANY IMPACTS OF PRIOR CONVECTION BECOME BETTER RESOLVED. FURTHER SOUTH INTO THE CENTRAL PLAINS...ISOLATED STRONG TO SEVERE STORMS ARE MORE CONDITIONAL DUE TO WEAKER FORCING FOR ASCENT AND MORE MODEST DEEP LAYER SHEAR. SHOULD A STORM DEVELOP ALONG THE SURFACE TROUGH/DRYLINE...STRONG WINDS AND LARGE HAIL WOULD BE POSSIBLE.
7 Day Rainfall Outlook
The sunny, dry, comfortable weather as of late certainly has been a treat. Enjoy it while you can because unsettled and wetter weather returns late weekend into next week. According to NOAA's WPC, the 7 day rainfall forecast suggests fairly widespread 1" to 3"+ rainfall through the end of next week.
Extended Weather Outlook
The extended temperature outlook through the first full week of September suggests a bit of a warm up by the end of the weekend and into early next week with muggier dewpoints as well. However, it appears that it won't last too long as readings settle back to near normal levels by the middle and end of the week.
6 to 10 Day Temp Outlook
According to NOAA's CPC, the 6 to 10 day temperature outlook suggests a fairly decent chance of warmer than normal conditions settling in around the Great Lakes Region during the first full week of September. A bigger blob of cooler air will settle in across the Northwestern part of the country, which may drift our way as we approach the 2nd weekend of the month.
6 to 10 Day Temp Outlook
The national outlook suggests that much of the eastern part of the country will remain above average, however, there will be a fairly significant pocket of below average temps across the central and northern Rockies. 
High Elevation Snow?
Take a look at this! The National Weather Service has issued a Winter Weather Advisory for parts of western Montana above 7000ft. for snowfall accumulations that could approach 2" to 5" from Sunday into Monday.
...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM NOON SUNDAY TO NOON MDT MONDAY ABOVE 6000 FEET...
* IMPACTS/TIMING: AN EARLY SEASON STORM WILL DEVELOP SUNDAY MORNING IN SOUTHWESTERN MONTANA AND TRACK NORTH TOWARD CANADA MONDAY AFTERNOON. UNUSUALLY COLD TEMPERATURES WILL PRODUCE SNOW ABOVE 6000 FEET. AREAS OF CONCERN ARE MAINLY BACKCOUNTRY ROADS AND RECREATIONAL AREAS ABOVE 6000 FEET...SUCH AS GEORGETOWN LAKE AND SKALKAHO PASS. CAMPERS...HIKERS...AND HUNTERS SHOULD PLAN FOR RAW AND WINTRY BACKCOUNTRY CONDITIONS IN THESE AREAS STARTING SUNDAY AFTERNOON AND OVERNIGHT INTO MONDAY MORNING. LOST TRAIL PASS COULD SEE LIGHT SNOW ACCUMULATIONS FOR BRIEF PERIODS OF TIME WITH THE HEAVIER PRECIPITATION...THOUGH EXPECTED TO MELT FAIRLY QUICKLY.
* SNOW ACCUMULATIONS: 1 TO 2 INCHES AROUND 6000 FEET WITH 2 TO 5 INCHES ABOVE 7000 FEET.


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National Weather Outlook
The national weather outlook shows Hermine lifting northeast along the coast, which in turn will have impacts across the rest of the nation. Tropical systems tend to have ripple effects on other weather systems, so things don't move along as quickly as they otherwise would. High pressure will linger a little longer across the Great Lakes and unsettled, wetter weather will linger across the Plains over the next few days as Hermine creates a traffic jam in the East.
Precipitation Outlook
According to NOAA's WPC, the 5 day forecast suggests heavier rain associated with Hermine will stay mainly offshore. Meanwhile, several rounds of showers and storms will keep the threat of locally heavy rainfall in place over the Midwest through much of the week.

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Lester in the Pacific
Here's a view of Hurricane Lester in the Central Pacific Ocean, which will be bearing down on the Hawaiian Islands as we head into the weekend. As of PM Thursday, Lester was a category 3 hurricane with sustained winds of 120mph with a very defined eyewall; see below.

Tracking Lester
After making a close encounter with the Hawaiian Islands, Lester will continue to drift north away from the Islands through the early week time frame. 
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"Paris climate deal: US and China formally join pact"

"The US and China - together responsible for 40% of the world's carbon emissions - have both formally joined the Paris global climate agreement. After arriving with other leaders of G20 nations for a summit in the city of Hangzhou, Mr Obama said: "History will judge today's effort as pivotal." CO2 emissions are the driving force behind climate change. Last December, countries agreed to cut emissions enough to keep the global average rise in temperatures below 2C. The Paris deal is the world's first comprehensive climate agreement. It will only come into force legally after it is ratified by at least 55 countries, which between them produce 55% of global carbon emissions. Members of China's National People's Congress Standing Committee adopted "the proposal to review and ratify the Paris Agreement" on Saturday morning at the end of a week-long session."


 
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Thanks for checking in and have a great end of your week and weekend ahead!
Don't forget to follow me on Twitter @TNelsonWX

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