Use of the 500 mb Chart at Sea

The 500mb forecast chart is an excellent tool for mariners to estimate where to anticipate the heaviest sea and swell conditions as well as a guide to the expected surface storm tracks and intensities.  The closer the height contours on the 500mb chart, the faster the upper level wind flow, the stronger the temperature contrasts and the more active is the surface weather below. The development and strengthening of surface lows and the associated bad weather most often occurs on the eastern side of 500mb troughs while surface high pressure and good weather is associated with the western side of these troughs.  Without even looking at the surface pressure charts, a mariner can estimate what areas might be best to avoid.

Today’s 500 mb chart of the North Pacific is a good example.

NOAA OPC 500 mb Analysis Dec 

Note the actual significant wave height analysis 

Click here to read more about using the 500 mb chart at sea.

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North Atlantic Storm to trigger Gulf of Lion gale to storm winds

NOAA OPC Surface Analysis 18Z 8 Dec 2019

Earlier today a hurricane-force storm system west and north of of Ireland was producing storm to hurricane force winds and seas to 15 meters (49 ft).

 

This system will trigger gale to storm force winds over the Gulf of Lion Monday into Tuesday.

Wind Forecast Tuesday morning for Gulf of Lion – Image credit buoyweather.com

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HURRICANE FORCE WIND WARNING…NORTH PACIFIC

NOAA OPC 00Z 9th Dec Surface Analysis

A rapidly deepening storm low over the central North Pacific near 40 N Latitude will result in winds of 50-65 knots and seas building to 45 feet (nearly 14 meters) south and southwest of the center over the next 24-48 hours.  This system will create high winds and waves in the main North Pacific shipping lanes.

NOAA OPC 48 hour surface forecast

 

 

NOAA OPC 48 hour Wave Height Forecast

 

 

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Tropical Cyclone Belna heading for Madagascar

TC Belna Satellite image

Tropical Cyclone Belna over the South Indian Ocean NNE of Europa Island has been moving SSW at 5 knots with max winds currently estimated at 90 knots.  Belna is expected to make landfall along the west coast of Madagascar thenl turn more southward over western Madagascar and weaken rapidly. 

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Two Tropical Cyclones developing over the South Indian Ocean

First Tropical Cyclone

Satellite IR image TC 02S

Tropical Cyclone (02S) has formed over the South Indian Ocean NNW of St Denis, Reunion and is moving WSW at about 4 knots with max winds of 40 knots. This system is moving through an area of low vertical wind shear and warm ocean temperatures so deepening to hurricane strength is expected within 36-48 hours.  A more S-SW track is expected bring the system near the northwest coast of Madagascar in 4-5 days. 

TC 02S Forecast track

 

Second Tropical Cyclone

TC Ambali Satellite Image

A second Tropical Cyclone (Ambali) has formed WSW of Diego Garcia over the southern Indian Ocean and was moving SW at 8 knots with max winds already at 70 knots. Ambali has been rapidly deepening over warm ocean water with low vertical wind shear. Ambali could reach a max intensity of 100 knots or more over the next 12-24 hours. Gradual weakening is expected after 24-36 hours as Ambali continues on a SW track. 

TC Ambali Track Forecast

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What is Weather Routing Vs. Vessel Performance Monitoring?

There are two general types of operational weather services provided by weather routing companies:  Optimum Ship Routing and Vessel Performance Monitoring

Weather Routing

Global Marine Shipping Routes

Optimum Ship Routing (Weather Routing)

Optimum ship routing is the art and science of developing the “best route” for a ship based on the existing weather forecasts, ship characteristics, ocean currents and special cargo requirements. For most transits this will mean the minimum transit time that avoids significant risk to the vessel, crew and cargo. Other routing considerations might include passenger comfort, fuel savings or schedule keeping. The goal is not to avoid all adverse weather but to find the best balance to minimize the time of transit and fuel consumption without placing the vessel at risk to weather damage or crew injury.

A preliminary routing message is transmitted to the master of a vessel prior to departure with a detailed forecast of expected storm tracks and areas of heavy seas.  An initial route proposal is offered along with the reasoning behind the recommendation and also the expected weather conditions to be encountered along the proposed route.  Sometimes an alternate route may be suggested for the master’s consideration. This allows the master to better plan his route and offers an opportunity to communicate with the routing service any special concerns that he or she might have due to special cargo requirements, ship condition or schedule requirements.. Once the vessel departs, the vessel’s progress is monitored closely with weather and route updates sent periodically, as needed.

Weather Routing services save ship operators money by reducing the average time of transit and therefore also saving on fuel. By avoiding the worst weather conditions, weather routing minimizes the risk for damage to cargo or ship as well as the risk of injury to crew or passengers. Over time, routed ships benefit from reduce insurance premiums as well based on an improved track record.

Modern ship routing ideas began during the early stages of WWII when the US Navy established the “Naval Meteorology and Oceanography Center” at the Naval Air Station in Norfolk in 1958. “Optimum Track Ship Routing” (OTSR) was started to provide tailored safety and cost saving routing services to all ships utilized by the military for long duration open ocean voyages.

Commercial marine weather routing had it start in the 1950’s when Howard Kaster, a meteorologist for United Airlines, started a company called “Pacific Weather Analysis Corporation” which later evolved into Ocean Routes under Ray Maier and Bill Dupin. Other pioneers of commercial ship routing in the 1960’s included Bill Kaciak the founder of “Weather Routing Inc.”, Louis Allen who started “Allen Weather Corp” and “Bendix Marine Science Services” under Robert A Raguso.  You can read more about the history of Optimum Ship Routing here. 

 

Vessel Performance Analysis (Performance Monitoring)

Vessel Performance Report Daily positions

Vessel performance monitoring services allow a ship operator, owner or charterer to get a daily performance analysis regarding a vessel’s speed and fuel consumption based on the charter-party specifications and the actual weather and currents encountered. Although no weather or routing advice is offered, alerts can be generated to the vessel owner, operator or charterer whenever a performance issue is discovered enroute so that the charterer or vessel operator/owner has a “heads-up” on performance issues prior to the ship’s arrival.

Vessel Performance Analysis

At the end of the voyage, a full “Voyage Performance Evaluation Report” is generated to offer a more detailed look at the actual performance or non-performance of the vessel. This report will look at several factors, including the charter party terms, the actual speed and consumption, whether the vessel was in ballast or in a laden condition and the actual wind, sea, swell and ocean currents encountered. In addition, the performance during “good weather conditions” as specified in a charter party agreement is often reviewed separately. This type of report can allow a charter to withhold hire or gives the owner/operator a better opportunity to negotiate a settlement or head-off an unwarranted speed claim.

For more information please visit the Ocean Weather Services website: http://www.oceanweatherservices.com/

 

Fred Pickhardt
Ocean Weather Services

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Typhoon Kammuri to impact Philippines

IR Satellite image Typhoon Kammuri

Typhoon Kammuri over the western North Pacific east of the Philippines is moving westward at 9 knots with max winds of 70 knots. Environmental conditions are favorable for further intensification and Kammuri is expected to reach near 100 knots prior to making landfall over the Philippines in about 24 hours. 

Typhoon Kammuri estimated wind field

 

 

The center of kammuri is forecast to pass near Subic Bay and Manila before passing westward over the South China Sea.

Typhoon Kammuri forecast track via JTWC

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Typhoon Kammuri to threaten Philippines

Typhoon Kammuri Satellite Image

Typhoon Kammuri over the western North Pacific east of the Philippines has been moving northward at 8 knots with max winds currently at 75 knots.  Kammuri is moving over warm ocean water with low to moderate vertical wind shear.  

Kammuri is forecast to slow or become stationary during the next 12-18 hours then turn westward in response to building high pressure to the north.  Intensification is forecast during the next 72 hours reaching max winds of 120-130 knots as it heads towards the Philippines. The current track has Kammuri reaching the Philippines on Dec 3rd between 00Z and 12Z.

Typhoon Kammuri forecast track from JTWC

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Typhoon Developing over western North Pacific

Satellite Image TS Kammuri

Tropical Storm Kammuri over the western North Pacific SW of Guam has been moving west at 12 knots and is moving over warm ocean water with low wind shear. 

 

Max winds currently at 55 knots is forecast to intensify to typhoon strength shortly and to over 100 knots in about 72 hours.  Kummuri is expected to turn NW or NNW within 24 hours. After about 72 hours, Kummuri is forecast to turn back to a westerly track.

Forecast Track Kammuri

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Hurricane Force Storm expected along US West Coast

A rapidly deepening storm low is forecast to develop over the eastern North Pacific by early Tuesday moving east-southeastward reaching the US West Coast by Tuesday evening with winds of 55-70 knots and seas building up to 38 feet (11.6 meters) within 180 nm west and southwest of the center. 

Northern California Coast from Point St. George to Point Arena between 60 NM and 150 NM offshore- NOAA Marine Forecast

…HURRICANE FORCE WIND WARNING…

TONIGHT…N winds 20 to 30 kt. Seas 11 to 14 ft.
TUE…SW winds 15 to 25 kt, becoming W 50 to 60 kt. Seas 10 to 12 ft, building to 14 to 23 ft.
TUE NIGHT…NW winds 55 to 70 kt, diminishing to 35 to 45 kt. Seas 24 to 39 ft. Scattered showers and tstms.

NOAA OPC Forecast Surface map for 1200 UTC 26 November 2019

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