What does a “Gale Warning” mean?

The National Weather Service has developed a multi-tier concept for forecasting hazardous weather which includes outlooks, watches, warnings and advisories.  Below are the visual day flag and nighttime light signals that warn of rough weather.  NOAA discontinued using the flags in 1989, however, the Coast Guard reestablished them in 2007 at selected small boat stations across the country. http://www.nws.noaa.gov/om/marine/cwd.htm

NOAA Coastal Warning Display System

An outlook is issued to indicate that a hazardous weather or hydrologic event may occur over the next several days. 

A watch is issued whenever that risk has increased significantly but the occurrence, location or timing are still uncertain. Marine Watches for “GALE” “STORM”, and “HURRICANE FORCE” wind conditions, not related to tropical cyclones, can be highlighted in extended range forecasts beyond 24-hours for coastal inland waters, and offshore waters (does not include high seas forecasts). 

A warning is issued when the hazardous condition or event is either occurring, imminent or likely (for the marine forecasts, within 24-hours). 

A weather advisory is issued when a hazardous weather condition or event is occurring, imminent or likely but for less serious conditions than those that would warrant a warning. 

A Gale Warning  is issued when sustained surface winds (averaged over a ten minute period, momentary gusts may be higher) of 34 knots (39 mph) to 47 knots (54 mph) are either occurring, imminent or likely (for the marine forecasts, within 24-hours). 

“Developing Gale” refers to an extratropical low or an area in which gale force winds of 34 knots (39 mph) to 47 knots (54 mph) are “expected” by a certain time period. On surface analysis charts, a “DEVELOPING GALE” label indicates gale force winds within the next 24 hours. When the label is used on the 48 hour surface forecast and 96 hour surface forecast charts, gale force winds are expected to develop by 72 hours and 120 hours, respectively.

NOAA OPC Surface Analysis Chart

 Fred Pickhardt, chief meteorologist,
Ocean Weather Services
http://www.oceanweatherservices.com

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Major Hurricane Florence Update

Hurricane Florence Satellite image via NOAA

Major Hurricane Florence currently with max winds about 120 knots was moving west at 11 knots.  A building ridge to the north is forecast to steer Florence WNW then NW during the next 48-72 hours with an increase in forward speed.  Conditions remain favorable for deepening with max intensity possibly reaching 130-140 knots.  Increasing wind shear forecast in about 72 hours may weaken the max winds just prior to landfall late Thursday night along the coast of North Carolina.

NOAA NHC Forecast Track

Key Messages from the NHC:

1. A life-threatening storm surge is likely along portions of the coastlines of South Carolina, North Carolina, and Virginia, and a Storm Surge Watch will likely be issued for some of these areas by Tuesday morning. All interests from South Carolina into the mid-Atlantic region should ensure they have their hurricane plan in place and follow any advice given by local officials.

2. Life-threatening freshwater flooding is likely from a prolonged and exceptionally heavy rainfall event, which may extend inland over the Carolinas and Mid Atlantic for hundreds of miles as Florence is expected to slow down as it approaches the coast and moves inland.

3. Damaging hurricane-force winds are likely along portions of the coasts of South Carolina and North Carolina, and a Hurricane Watch will likely be issued by Tuesday morning.  Damaging winds could also spread well inland into portions of the Carolinas and Virginia.

4. Large swells affecting Bermuda and portions of the U.S. East Coast will continue this week, resulting in life-threatening surf and rip currents.

Hurricane Florence Rainfall Forecast

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Hurricane Florence now Cat 4

 

NOAA Satellite image Hurricane Florence

Major Hurricane Florence continues to develop with max winds now at 115 knots (Cat 4). Florence is moving in an area where wind shear is forecast to increase during the next 48 hours so Florence is expected to weaken somewhat  but could again intensify thereafter.

NHC Forecast track with possible longer range tracks

Florence is moving towards the northwest at about 11 knots but a strengthening ridge to the north should cause a more westward track for a while. Thereafter, the track becomes uncertain with some models turning Florence northwest the north while others suggest Florence could move close to the US East Coast before turning.  If this happens, areas from the Carolinas to New England could be affected next Wednesday through Friday.

Estimated Wind Field Hurricane Florence

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Hurricane Lane threatens Hawaiian Islands

Hurricane Lane Satellite image

Hurricane Lane over the central North Pacific has max winds of 125 knots and was moving northwestward towards the Hawaiian Islands and is forecast to turn more towards the north during the next 24-36 hours.  In 48-72 hours track guidance suggests that Lane will start turning back to a more westward track and the timing of that shift could make a significant difference over the Hawaiian Islands.  Increasing wind shear will gradually weaken Land during the next 48 hours, with more rapid weakening thereafter.

NOAA NHC Forecast Track

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Typhoon Soulik to impact South Korea

Typhoon Soulik satillite image

Typhoon Soulik over the western North Pacific was located about 192 nm WSW of Sasebo,Japan and was moving towards the NW at 7 knots.  Max winds currently estimated near 85 knots with hurricane force winds extending outward about 30 nm to the southwest and 40 nm to the northeast.

 

 

 

Soulik will begin to turn more towards the north then northeast making landfall along the west coast of South Korea near Kunsan between 12:00 and 18:00 UTC on the 23rd with max winds of about 65 knots.

JTWC forecast track

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Typhoon Cimaron bears down on Japan

Typhoon Cimaron satillite image

Typhoon Cimaron over the western North Pacific was located about 245 nm WMW of Iwo To and was moving northwest at 19 knots.  Currently, max winds are estimated at about 100 knots with the hurricane force winds concentrated north and east of the center.

Cimaron has already reached its peak intensity and is forecast to gradually weaken making landfall over eastern Shikoku at about 12:00 UTC on the 23rd with max winds near 80 knots, then move northward across Honshu into the Sea of Japan.

Typhoon Camaron wind field analysis

JTWC Forecast Track suggests landfall around 12:00 UTC 23rd.Cimaron

JTWC forecast track

 

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Predictability of Atlantic hurricanes

By Judith Curry
Cayman Financial Review 

Hurricane Irma

The 2017 Atlantic hurricane season was remarkable, including five landfalls of Category 5 storms in the Caribbean Basin, and three Category 4 strikes on the U.S. coastline. The 2017 landfalls cost hundreds of lives and record-breaking economic losses, exceeding $250 billion. These losses are sober reminders of hurricane vulnerability and the importance of hurricane prediction for public safety and the management of insurance and other economic risks.

Hurricane forecasts have continued to improve in recent years, but they are not yet as good as they could be. Continued advances in weather and climate computer models used to make forecasts, and improved observations from satellites and aircraft are driving these improvements. Also, essential to progress are advances in understanding of weather and climate dynamics.

Read full article here

Note:  Dr. Judith Curry is founder and President of  Climate Forecast Applications Network

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Typhoon Jongdari to hit Japan

Typhoon Jongdari Satellite image

Typhoon Jongdari located about 239 nm SE of Yokosuka, Japan is moving N-NW at 23 knots with max winds of 85 knots and max significant wave heights estimated at 40 ft. Forecast indicate that Jongdari will turn northwest then west making landfall over Japan between Tokyo and Osaka about 1500 UTC on the 28th with max winds about 75 knots.

JTWC Typhoon Forecast Track

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Typhoon Threat to Honshu Japan

Satellite image TD 15W developing over the western North Pacific

A developing Tropical Depression (15W) located about 376 nm southwest of Iwo To, Japan was moving northward at 9 knots with max winds currently about 30 knots but likey close to tropical storm strength. Slow development is anticipated for the next 24-36 hours, after which conditions become more favorable with typhoon strength likely in about 48 hours.

A north to northeast motion is forecast for the next 48 hours then a turn towards the north and northwest is anticipated which could bring the center over Honshu Japan near Tokyo about 0000 UTC July 29th  with winds to 80-85 knots.

JTWC forecast track for TD 15W

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TS Chris nears Hurricane Strength off US East Coast

NOAA Satellite image TS Chris

TS Chris continues to strengthen off the US East Coast with max winds at 60 knots is close to reaching hurricane strength. Chris is nearly stationary but is forecast to begin moving towards the northeast in about 36 hours.

Estimated wind field for TS Chris

 

Chris is expected to move across the offshore waters of Atlantic Canada on days 4 and 5 as a powerful extra-tropical low, possibly passing over southeastern Newfoundland around the 96-hour time period.

NHC Forecast Track TS Chris

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