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Bill SammlerWarning Coordination Meteorologist
National Weather Service –Wakefield, VA
Eastern Shore Weather and
Climate
About The NWS►The National Weather
Service is:►A Federal Government Agency►Part of the Dept. of Commerce►Nat’l Oceanic and Atmospheric
Admin. (NOAA) is our Parent Agency
►A 4700 Employee Agency Dedicated to Saving Lives and Protecting Property
►WFO Wakefield is 1 of 122 local offices nationwide (including Puerto Rico & Guam)
“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”
NWS Field Office Structure
NWS in the Mid‐Atlantic
• Provide climate, water, weather forecasts and warnings to protect life and property and enhance the economy
• 76 billion observations
• 1.5 million forecasts
• 50,000 warnings
A Typical Year Brings:
– 6 Hurricanes– 1,000 Tornadoes– 5,000 Floods– 10,000 Violent Thunderstorms– Drought Conditions– 500 Deaths; 5,000 Injuries;
$14 Billion in Losses
NOAA’s National Weather Service
Weather ForecastingMost only see the “Tip of the Iceberg”
NWS TechnologyWSR-88D Doppler Radar
AWIPS Data Ingest
Advanced Weather Interactive Processing
System (AWIPS)
Automated Surface Observation
System (ASOS)
Weather Versus ClimateWeather Versus Climate
Weather is what you get Now:• Temperature• Moisture• Air Pressure• Wind Speed/Direction
Climate is what happened in the past, and what you might expect in the Future:• Based upon recent past• Defined by the World Meteorological Organization (WMO)• 30 year average of daily weather
Weather is what you get Now:• Temperature• Moisture• Air Pressure• Wind Speed/Direction
Climate is what happened in the past, and what you might expect in the Future:• Based upon recent past• Defined by the World Meteorological Organization (WMO)• 30 year average of daily weather
What is the 2nd Biggest Influence on All Weather and Climate?
The Oceans!!!
Ocean Temperature Changes
El Nino and La Nina• El Nino and La Nina are Pacific OCEAN Phenomena– SSTs Warmer (El Nino) or Colder (La Nina) than Normal
• El Nino and La Nina Produce Significant Short‐term Climate/Weather Anomalies
• The Stronger the Ocean Signal, the Stronger and More Predictable the Atmospheric Response
El Nino and La Nina
La Nina
El Nino
El Nino/La Nina ImpactsEl Nino LA Nina
Geography and VA Weather
• Summer– Water Warm/LandWarm/Hot
• Bay/Ocean Become Moisture Sources
• Sea Breezes• Tstms Develop Along Mtns and Sea Breeze Fronts
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Sea Breeze
Copyright 1992, USA TODAY. Reprinted with permission.
Land heats up more quickly than water
Cold air begins to push inland creating a breeze off the ocean
Rising warm air cools and moves over the ocean to replace cold air that moved inland
Sea/Bay Breeze Example
June 29, 2001
Thunderstorms
Bay/Ocean Convergence Zone
Geography and VA Weather
• Fall– Water Warm/Land Cooling
• Bay/Ocean Still Provide Moisture
• Cold Fronts Can Be Dramatic (Wind)
• Growing Season and Tornado Season End Later
Dates of First/Last Freezes
First Fall Freeze
Last Spring Freeze
Geography and VA Weather
• Winter– Water Cold/Land Cold (Usually)
• Less Snow Near Coast due to Water Temps– Wind Direction Key– Mtns Help “Hold In” Cold Air Inland (Damming)
• Late Winter Warming Can Be Slowed Near Ocean
Cold Air Damming
H
Nor’eastersWell organized low pressure intensifies over Gulf Stream and collides with cold air from the north
November 2009 Nor’Easter (Nor’Ida)
How many East Coast lowsper season?
How many East Coast lowsper season?
• Typically in a winter season (10/15‐ 3/31) we have between 11‐15 coastal winter storm events (Cione, 1993; Sanders, 1980)
• Most of these storm events occur from December through February with January being the month with the most storm events.
• Most of these storms do their intensifying from Cape Hatteras northward
January 4th 2018 BlizzardStorm Evolution 7am Wed – 7 am Fri
AKQ Snow Amounts
PHI Snow Amounts
Blizzard Definition• Sustained wind or frequent gusts
greater than or equal to 35 mph
• Falling and/or blowing snow
• Frequently reducing visibility to less than 1/4 mile
for three hours or more.
Accomack Observations
Tangier Isl. Observations
RPLV2 Observations
Unusual TidesCambridge, MD Ocean City, MD
Unusual TidesWachapreague, VA
MLLW
Unusual TidesKiptopeke, VA
MLLW
Early March Nor’Easter/Wind
Storm
Surface Low Evolution
March 1‐5 Winds
Chesapeake Bay Bridge Tunnel
Rappahannock Range Light
Geography and VA Weather
• Spring– Water Cold/LandWarming
• Warming Near Coast can be Slowed
• Sea Breezes• Back Door Fronts• Reduced Severe Thunderstorms Near Bay/Ocean (early)
Back Door Cold Front
April 7, 2001
Hurricanes/Tropical Systems
Tropical Cyclone Climatology
Tropical Cyclone Probabilities – By Month
All Tropical Systems 1899 – 2016
(passing within 100 miles of Norfolk, VA)
Hurricanes 1899 - 2016(passing within 100 miles of
Norfolk, VA)
How many hurricanes havetracked into the Bay?
How would such an event compareto past disasters?
Help observe precipitation in your community !!
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www.cocorahs.org
4” diameter plastic rain gauge and 10 minutes a day!
It’s fun and easy. We need your help!
Around 7 am
Gauge measures to the hundredth of an inch
CoCoRaHS observers help provide a much better post‐storm analysis picture!
Without CoCoRaHS data With CoCoRaHS data
Volunteers take their readings once a dayObservers can easily transmit their observations using mobile devices
7.12”, 24-hour amount - May 6, 2008, New Braunfels, Texas
Your observation can make a difference!
“All but 0.02” fell between 3:30 and 5:30PM.”Station TX-CML-17
Radar image of the isolated storms
How can I join the network?
Sign-up on the CoCoRaHS web page:www.cocorahs.org
Obtain a 4” plastic rain gauge
Set-up the gauge in a “good”location in your yard
Start observing precipitation and report on-line
Five easy steps
View the on-line “training slide show” or attend a
training session
