Forecasting Marine Weather Mark Strobin Senior Meteorologist NWS - Monterey, CA Saturday January 16, 2010

The forecast process Tornado getting ready to touch down in Sacramento, Monday, February 22, 2005

Analyze Current Conditions http://www.nrlmry.navy.mil/sat_products Satellite data - clouds and precipitation IR Imagery http://www.nrlmry.navy.mil/sat_products

Analyze Current Conditions http://www.nrlmry.navy.mil/sat_products Satellite data - clouds and precipitation Visible Imagery http://www.nrlmry.navy.mil/sat_products

Analyze Current Conditions http://www.jpl.nasa.gov Satellite data derived winds (QuikSCAT) http://www.jpl.nasa.gov

Analyze Current Conditions Buoy reports -text format

Analyze Current Conditions http://www.ndbc.noaa.gov Buoy reports -NDBC web site http://www.ndbc.noaa.gov

Analyze Current Conditions Buoy reports -NDBC web site, detailed buoy info www.ndbc.noaa.gov

Analyze Current Conditions Buoy reports -NDBC web site, detailed wave summary www.ndbc.noaa.gov

Analyze Current Conditions Buoy reports and local swell models

Analyze Current Conditions Bay Reports

Farallon Island Observations Here is a link to automated Farallon Island Weather, updated hourly. http://www.weather.gov/oh/hads/ Box on the right, nwsli id, enter fndc1 Then press go A complicated form comes up, press Decoded Data at the bottom http://amazon.nws.noaa.gov/nexhads2/servlet/DecodedData Time is Zulu UD is wind direction in degrees US wind speed UG  wind gusts UP Peak speed UR wind direction of Peak TA Temp XR relative humidity PC Precipitation

Analyze Current Conditions Wind model

Analyze Current Conditions Radar http://www.weather.gov/sanfrancisco

Routine Forecast Products NWS Forecasts Routine Forecast Products - Coastal Waters Forecast - Small Craft Advisories (25-33 kt, squared seas) - Gale (34-47 kt), Storm (48-63 kt), Hurricane Force (63+ kt) Wind Warnings Non-Routine Forecast Products - Special Marine Warnings - Marine Weather Statements - High Surf Advisories - Coastal Flood Warnings, etc.

Routine Forecast Products Coastal Waters Forecast four coastal waters zones and two bay zones 1. Pt Arena to Pt Reyes out 10 nm 2. Pt Reyes to Pigeon Pt out to 10 nm 3. Pt Arena to Pigeon Pt 10-60 nm offshore 4. Pigeon Pt to Pt Pinos out 10 nm 5. pt pinos to Pt Piedras Blancas out to 10 nm 6. Pigeon Pt to Pt Piedras Blancas 10-60 nm offshore 7. San Francisco, San Pablo, Suisun Bays and the West Delta Delta 8. Monterey Bay

National Weather Service Our Forecast Area National Weather Service Forecast Office San Francisco Bay Area Public and Marine Forecast Zones

Forecast elements in coastal waters forecast Wind speed and direction Wind waves Swell height and direction Swell period (only for first 36 hours) Significant weather (only for first three days) Synopsis of current weather situation Forecast periods are 12 hours long for first three days and then 24 hours long for days 4-5

Advisory and warning criteria Small Craft Advisory: 22-33 knots Gale Warning: 34-47 knots Storm Warning: 48-63 knots Hurricane Force: 64 knots or greater Small Craft Advisory: Square seas or steeper High Surf Advisory: 15 foot waves

San Francisco Bar

San Francisco Bar

San Francisco Bar

San Francisco Bar Forecast Small Craft Advisory for Rough Bar issued if seas are 10 feet or greater on the Bar. .....SAN FRANCISCO BAR/FOURFATHOM BANK FORECAST..... IN THE DEEP WATER CHANNEL...COMBINED SEAS 6 TO 8 FT THIS EVENING THROUGH SATURDAY. ACROSS THE BAR...COMBINED SEAS 6 TO 8 FT THIS EVENING THROUGH SATURDAY. SEAS MOSTLY WIND WAVE THIS EVENING...TRANSITIONING TO MOSTLY SWELL BY LATE TONIGHT. SEAS OCCASIONALLY TO 9 FEET DURING MAXIMUM EBB CURRENT OF 1.4 KT AT 2:45 AM SATURDAY MORNING AND AGAIN DURING MAXIMUM EBB CURRENT OF 2.4 KT AT 2:19 PM SATURDAY AFTERNOON.

Non-Routine Advisory Products High Surf Advisory - issued when significant wave heights of 15 feet or greater are expected - research underway to see if criteria should be modified to include wave period. (i.e. 14 ft swell with a 19 second period has a much larger impact on the coast than a 16 ft swell with a 9 second period)

Non-Routine Advisory Products High Surf Warning - issued when significant wave heights of 20 feet or greater are expected

Non-Routine Advisory Products Marine Weather Statement - issued as a “heads up” for hazardous weather - large-scale Pacific storms approaching the California coast - unusually high surf and/or rip currents - organized areas of non-severe thunderstorms - other hazardous weather (dense fog, etc.)

Non-Routine Warning Products Special Marine Warnings A severe local storm warning informing mariners of short term hazards not covered by existing forecasts and warnings. Usually for convective storms. - waterspouts - funnel clouds - severe thunderstorm (i.e., ¾ inch hail or winds >34 kts) Rare in California, but can occur.

Forecast dissemination Dissemination methods - NOAA Weather Radio - Internet - Coastal Waters (out to 60 nautical miles) http://www.weather.gov/sanfrancisco - Offshore Waters (60-250 nautical miles and beyond) http://www.opc.ncep.noaa.gov - Others (info at http://www.wrh.noaa.gov/mtr/marine.php) Radiofax PORTS EMWIN/EDIS NOAA Weather Wire Services

NOAA Weather Radio transmitters Big Rock Ridge – marine radio KDX 54

Forecast dissemination http://www.weather.gov/sanfrancisco Local NWS Website http://www.weather.gov/sanfrancisco

Forecast dissemination Digital (Graphical) Forecast

Questions? Contact info: Mark Strobin 831-656-1710 mark.strobin@noaa.gov