don’t be surprised by the expected!

National Weather Service


Don’t be Surprised byDon’t be Surprised bythe Expected!the Expected!

Sometimes warnings are issued Sometimes warnings are issued without prior notice.without prior notice.

How can you be prepared?How can you be prepared?

By monitoring forecasts and By monitoring forecasts and discussions.discussions.


Tiered Approach of NWSProducts

Certainty of event

Watches

Warnings /Advisories

Outlooks


OutlooksOutlooks

1. Long Range -- Usually 2 days or 1. Long Range -- Usually 2 days or more.more.• E.g. Hurricane crossing Puerto Rico.E.g. Hurricane crossing Puerto Rico.• Winter Storm forming over the Gulf of Winter Storm forming over the Gulf of

Mexico.Mexico.2. Provides opportunity to make 2. Provides opportunity to make contingency plans.contingency plans.3. Outlooks discuss the uncertainty of 3. Outlooks discuss the uncertainty of longer range predictions.longer range predictions.


Outlooks Outlooks Outlooks are issued as Special Weather Outlooks are issued as Special Weather

Statements (SPS) for weather events.Statements (SPS) for weather events. Hazardous Weather Outlook (HWO) – issued Hazardous Weather Outlook (HWO) – issued

daily to cover 7 days – mainly for EMA daily to cover 7 days – mainly for EMA planning. planning.

It is used to highlight potential forIt is used to highlight potential for• High Winds High Winds • Excessive HeatExcessive Heat• Wind ChillWind Chill• Winter StormsWinter Storms• Severe Weather ThreatSevere Weather Threat• Flood PotentialFlood Potential


WatchesWatches

This means that hazardous or severe This means that hazardous or severe weather is a possibility, NOT a weather is a possibility, NOT a certainty. certainty. A "WATCH" is a long range prediction A "WATCH" is a long range prediction and is typically issued from 3 to 48 and is typically issued from 3 to 48 hours before the hazard is expected. hours before the hazard is expected.

If the storm becomes imminent or If the storm becomes imminent or more certain, the watch will be more certain, the watch will be upgraded to a "WARNING". upgraded to a "WARNING".


WatchesWatches

Flood (FFA) - issued a few to 24 hours in advance.Flood (FFA) - issued a few to 24 hours in advance.Severe Thunderstorm (WCN) - 3 to 6 hours in Severe Thunderstorm (WCN) - 3 to 6 hours in

advance.advance. Tornado (WCN) - 3 to 6 hours in advance.Tornado (WCN) - 3 to 6 hours in advance. Winter Storm (WSW) - 12 to 48 hours in advance.Winter Storm (WSW) - 12 to 48 hours in advance. High Wind (NPW) - 12 to 48 hours in advance.High Wind (NPW) - 12 to 48 hours in advance. Lake Effect Snow (WSW)- 12 to 48 hours in Lake Effect Snow (WSW)- 12 to 48 hours in

advance.advance. Wind Chill (NPW)- 12 to 48 hours in advance.Wind Chill (NPW)- 12 to 48 hours in advance. Excessive Heat (NPW)- 12 to 48 hours in advance. Excessive Heat (NPW)- 12 to 48 hours in advance.


WarningsWarnings

Issued for life-threatening weather Issued for life-threatening weather events.events.Issued when the hazardous weather is Issued when the hazardous weather is imminent, or occurring.imminent, or occurring.Lead times vary depending on the Lead times vary depending on the type of hazardous weathertype of hazardous weather A rule of thumb: the more localized a A rule of thumb: the more localized a weather hazard, the less lead time. weather hazard, the less lead time.

A WARNING is generally issued when a dangerous weather event is expected, imminent or occurring


WarningsWarnings Flash Flood (FFW)- 1 to 3 hoursFlash Flood (FFW)- 1 to 3 hours Flood – County (FLW)- 1 to 6 hoursFlood – County (FLW)- 1 to 6 hours Flood – River points (FLW)- 6 to 12 hours.Flood – River points (FLW)- 6 to 12 hours. Tornado (TOR)- 0 to 20 minutesTornado (TOR)- 0 to 20 minutes Severe Thunderstorm (SVR)- 0 to 20 Severe Thunderstorm (SVR)- 0 to 20

minutesminutes Blizzard or Winter Storm (WSW)- 6 to 36 Blizzard or Winter Storm (WSW)- 6 to 36

hourshours Lake Effect Snow (WSW)- 6 to 24 hours.Lake Effect Snow (WSW)- 6 to 24 hours. High Wind (NPW)- 6 to 24 hours.High Wind (NPW)- 6 to 24 hours. Wind Chill (NPW)- 6 to 24 hours.Wind Chill (NPW)- 6 to 24 hours. Excessive Heat (NPW)- 6 to 24 hours. Excessive Heat (NPW)- 6 to 24 hours.


AdvisoriesAdvisories

0 to 24 hours (Occurring, imminent 0 to 24 hours (Occurring, imminent or high probability).or high probability).

Event considered an inconvenience Event considered an inconvenience but could threaten life and property but could threaten life and property if proper precautions are not taken.if proper precautions are not taken.

Issued for winter weather, wind, Issued for winter weather, wind, flooding, and fog.flooding, and fog.


Advisories Advisories

Wind (NPW) - 6 to 24 hoursWind (NPW) - 6 to 24 hours

Flood Advisory (FLS) - 0 to 12 hoursFlood Advisory (FLS) - 0 to 12 hours

Wind Chill (NPW)- 6 to 24 hoursWind Chill (NPW)- 6 to 24 hours

Excessive Heat (NPW)- 6 to 24 hoursExcessive Heat (NPW)- 6 to 24 hours

Dense Fog (NPW)- 6 to 24 hoursDense Fog (NPW)- 6 to 24 hours

Lake Effect Snow (WSW)- 6 to 24 hoursLake Effect Snow (WSW)- 6 to 24 hours


Statements Statements

Statements are issued to provide updates on Statements are issued to provide updates on on-going or expected weather hazards. on-going or expected weather hazards. • Short Term Forecasts (NOW) Short Term Forecasts (NOW) • Flash Flood (FFS) Flash Flood (FFS) • Flood (FLS) Flood (FLS) • Special Weather (SPS) Special Weather (SPS) • Severe Weather (SVS) Severe Weather (SVS) • River (RVS) River (RVS) • Drought (ESF) Drought (ESF) • Flood Potential (ESF) Flood Potential (ESF) • Public Information (PNS)Public Information (PNS)


Short Term Forecasts (NOW)Short Term Forecasts (NOW)

Issued for all types of hazardous weather.Issued for all types of hazardous weather.

Focuses on the next 1 to 6 hours of the event.Focuses on the next 1 to 6 hours of the event.

Thunderstorms, rain, snow and ice, fog, high Thunderstorms, rain, snow and ice, fog, high winds.winds.

Also used to provide forecasts of the beginning Also used to provide forecasts of the beginning and ending of precipitation events.and ending of precipitation events.

The short term forecast will have the latest The short term forecast will have the latest information on an on-going weather event!information on an on-going weather event!

The primary product to get the latest weather information during an ongoing (non-severe) weather event.


Short - Term ForecastShort - Term Forecast

CAN PREDICTCAN PREDICT0 to 1 hour - 0 to 1 hour -

Development and Development and movement of t-stormsmovement of t-storms

1 to 3 hours - Movement 1 to 3 hours - Movement of thunderstorm of thunderstorm systemssystems

3 to 12 hours - 3 to 12 hours - Movement of fronts Movement of fronts and upper level and upper level disturbancesdisturbances

CAN’T PREDICTCAN’T PREDICT0 to 1 hour - Exact 0 to 1 hour - Exact

location of tornado, location of tornado, downburst or haildownburst or hail

1 to 3 hours - Movement 1 to 3 hours - Movement of individual of individual thunderstormsthunderstorms

3 to 12 hours - 3 to 12 hours - Movement of Movement of thunderstorm systemsthunderstorm systems

Length vs. Accuracy


MiscellaneousMiscellaneous

State Forecast Product (SFT) State Forecast Product (SFT)

Record Report (RER) Record Report (RER)

Local Storm Report (LSR) Local Storm Report (LSR)

Precip/Temp Table (HYD, RTP) Precip/Temp Table (HYD, RTP)

Public Zone Forecast (ZFP) Public Zone Forecast (ZFP)

Climate message (CLI and CLM)Climate message (CLI and CLM)


MiscellaneousMiscellaneous Civil Emergency Message (CEM) Civil Emergency Message (CEM) Civil Danger Warning (CDW)Civil Danger Warning (CDW) Local Area Emergency (LAE)Local Area Emergency (LAE) Shelter in Place (SPW)Shelter in Place (SPW) Evacuation Warning (EVI)Evacuation Warning (EVI) Hazardous Material Warning (HMW)Hazardous Material Warning (HMW) Law Enforcement Warning (LEW)Law Enforcement Warning (LEW) 911 Telephone Outage (TOE)911 Telephone Outage (TOE) Earthquake Report (EQR)Earthquake Report (EQR) Earthquake Warning (EQW)Earthquake Warning (EQW)


Winter Storm CriteriaWinter Storm CriteriaMid Point Value Mid Point Value


Winter Storm Criteria Winter Storm Criteria


SeverethunderstormWatch/Warning

wind >/= 58 mph (50 kts) or hail greater >/= 3/4 inchWatch- conditions favorable for severe thunderstorms, warning-conditions imminent oroccurring.

TornadoWatch/Warning

Watch- conditions favorable for tornadic development Warning- tornado indicated by radar or reported

Flash FloodWatch/Warning

Flash Flood- flooding of smaller streams and rivers with a responsetime of less than 6 hrs Watch- conditions favorable for rapid flooding, flooding is apossibility Warning- rapid flooding imminent or occurring..

River FloodWarning

Flooding expected on larger rivers and streams that respond inmore than 6 hours.

Criteria for Severe Weather


Zone ForecastsZone Forecasts

Forecast zones are Forecast zones are areas of similar areas of similar weatherweather

Zones can be grouped Zones can be grouped if weather is same in if weather is same in the zonesthe zones

Zones are generally Zones are generally county-by-county.county-by-county.

1 to 3 days


Zone and State ForecastsZone and State Forecasts

CAN PREDICTCAN PREDICT12 to 48 hours - 12 to 48 hours - Movement and Movement and Development of large Development of large storms, general storms, general impact and threatened impact and threatened areas areas

CAN’T PREDICTCAN’T PREDICT12 to 48 hours - Exact 12 to 48 hours - Exact timing or location of timing or location of storm, intensification, storm, intensification, impact and dissipationimpact and dissipation

Length vs. Accuracy


Extended ForecastsExtended Forecasts

3 to 7 days3 to 7 days

Broad brushBroad brush

Not too many detailsNot too many details

General idea of what’s comingGeneral idea of what’s coming


Long Range OutlookLong Range Outlook

CAN PREDICTCAN PREDICT6 to 10 days - 6 to 10 days - General global General global patterns, patterns, temperature and temperature and precipitation with precipitation with respect to normal respect to normal

CAN’T PREDICTCAN’T PREDICT6 to 10 days - Exact 6 to 10 days - Exact temps and temps and precipitation precipitation amounts, timing of amounts, timing of global pattern global pattern changeschanges

Length vs. Accuracy


Forecast DiscussionsForecast Discussions

Used by forecasters to give reasoning Used by forecasters to give reasoning behind the forecastbehind the forecastOften uses contractions and jargonOften uses contractions and jargonCan be a wealth of informationCan be a wealth of informationAt times includes information about At times includes information about equipment outages (radar), equipment outages (radar), hydrology, marine, fire weatherhydrology, marine, fire weather

If you’re feeling technical...


Forecast DiscussionsForecast DiscussionsAREA FORECAST DISCUSSIONAREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV NATIONAL WEATHER SERVICE CHARLESTON WV 1029 AM EST WED JAN 10 20071029 AM EST WED JAN 10 2007 .SHORT TERM /REST OF TODAY/... .SHORT TERM /REST OF TODAY/... ALLOWED THE ADVISORY TO EXPIRE. COVERAGE/INTENSITY OF ALLOWED THE ADVISORY TO EXPIRE. COVERAGE/INTENSITY OF SNOW SHOWERS IS DECREASING ON 88D LOOP. EXPECT THIS TO SNOW SHOWERS IS DECREASING ON 88D LOOP. EXPECT THIS TO CONTINUE WITH PASSAGE OF H850 THERMAL TROUGH AND CONTINUE WITH PASSAGE OF H850 THERMAL TROUGH AND APPROACH OF SURFACE HIGH...CUTTING OFF NW FLOW. STILL A APPROACH OF SURFACE HIGH...CUTTING OFF NW FLOW. STILL A FEW ONGOING FLURRIES IN CENTRAL MOUNTAIN COUNTIES. SEE FEW ONGOING FLURRIES IN CENTRAL MOUNTAIN COUNTIES. SEE SOME CU DEVELOPMENT WEST OF THE MOUNTAINS...AS NEUTRAL SOME CU DEVELOPMENT WEST OF THE MOUNTAINS...AS NEUTRAL TO WEAK COLD ADVECTION WILL CONTINUE INTO THE AFTERNOON TO WEAK COLD ADVECTION WILL CONTINUE INTO THE AFTERNOON FOR A BIT. TWEAKED TEMPERATURES DOWN A DEGREE OR TWO UP FOR A BIT. TWEAKED TEMPERATURES DOWN A DEGREE OR TWO UP NORTH BASED ON MORNING SOUNDINGS AND LAMP...READINGS TO NORTH BASED ON MORNING SOUNDINGS AND LAMP...READINGS TO THE SOUTH LOOK GOOD. THE SOUTH LOOK GOOD. .PREV DISCUSSION... /ISSUED 603 AM EST WED JAN 10 2007.PREV DISCUSSION... /ISSUED 603 AM EST WED JAN 10 2007/ AVIATION /12Z-12Z/... / AVIATION /12Z-12Z/... SNOW SHOWERS CONTINUE THIS MORNING WITH 3 MAIN BANDS SNOW SHOWERS CONTINUE THIS MORNING WITH 3 MAIN BANDS NOW SET UP...ONE NEAR BKW THAT HAS BEEN MOVING THROUGH NOW SET UP...ONE NEAR BKW THAT HAS BEEN MOVING THROUGH WITH VARYING RESTRICTIONS FOR VISIBILITY. A SECOND BAND IS WITH VARYING RESTRICTIONS FOR VISIBILITY. A SECOND BAND IS NORTH OF CRW AND LOOKS AS IF IT WILL REMAIN NORTH OF THE NORTH OF CRW AND LOOKS AS IF IT WILL REMAIN NORTH OF THE SITE. A THIRD BAND IS NOW MOVING THROUGH LHQ TO EKN AND IS SITE. A THIRD BAND IS NOW MOVING THROUGH LHQ TO EKN AND IS IMPACTING PKB/CKB/EKN. BASED ON SATELLITE...THIS BAND IMPACTING PKB/CKB/EKN. BASED ON SATELLITE...THIS BAND SHOULD EXIT PKB AROUND 13Z...AND PULL OUT OF CKB AROUND SHOULD EXIT PKB AROUND 13Z...AND PULL OUT OF CKB AROUND 14Z AND EKN AROUND 15Z. 14Z AND EKN AROUND 15Z.


0

10, 20

30, 40, 50

60, 70

80, 90, 100

POP (%) Uncertainty CoverageNone used

Slight Chance

Chance

Likely

None used

None used

Isolated, few

Scattered

Numerous

None used

Interpreting ProbabilityInterpreting Probability


Internet productsInternet products

Tour our websites for additional text and graphical Tour our websites for additional text and graphical products at:products at:

www.weather.govwww.weather.govNew forecast digital database available for all users.New forecast digital database available for all users.


Accessing the National Digital Forecast Accessing the National Digital Forecast Database (NDFD) at the local levelDatabase (NDFD) at the local level


A New Forecasting ProcessA New Forecasting Process


Traditional Forecasting ProcessTraditional Forecasting Process

• Schedule DrivenSchedule Driven• Product OrientedProduct Oriented• Labor IntensiveLabor Intensive

National CentersNational CentersGenerate Graphical ProductsGenerate Graphical Products

National CentersNational Centers Model GuidanceModel Guidance

Field OfficesField OfficesType Text ProductsType Text Products

TODAY...RAIN LIKELY. SNOW LIKELY ABOVE 2500 FEET. SNOW ACCUMULATION BY LATE AFTERNOON 1 TO 2 INCHES ABOVE 2500 FEET. COLDER WITH HIGHS 35 TO 40. SOUTHEAST WIND 5 TO 10 MPH SHIFTING TO THE SOUTHWESTEARLY THIS AFTERNOON. CHANCE OF PRECIPITATION 70%.

MARYLAND EASTERN SHOREEASTONPTCLDY CLOUDY PTCLDY PTCLDY SUNNY PTCLDY60/52 63/54 65/47 55/40 55/37 50/33POP 20 POP 20 POP 20 POP 20 POP 10 POP 10

U.S. Drought U.S. Drought MonitorMonitor

Excessive Heat Excessive Heat ProductsProducts

Threats Threats AssessmentsAssessments


User-Generated ProductsUser-Generated Products

New Forecasting ProcessNew Forecasting Process

• InteractiveInteractive• CollaborativeCollaborative• Information Information

OrientedOriented

NWS Automated ProductsNWS Automated Products

TextText

GraphicGraphic

DigitalDigital

VoiceVoice

TODAY...RAIN LIKELY.

SNOW LIKELY ABOVE

2500 FEET. SNOW

ACCUMULATION BY

LATE AFTERNOON 1 TO

2 INCHES ABOVE 2500

FEET. COLDER WITH

HIGHS 35 TO 40.

SOUTHEAST WIND 5 TO

10 MPH SHIFTING TO

THE SOUTHWESTEARLY

THIS AFTERNOON.

CHANCE OF

PRECIPITATION 70%. National Digital National Digital ForecastForecast

Database Database

Local Digital Local Digital ForecastForecast

Database Database

Field Field OfficesOffices

National National CentersCentersCollaborateCollaborate

Data and Science FocusData and Science Focus

National CentersNational Centers Model GuidanceModel Guidance

GridsGrids



From Text to 3DsFrom Text to 3Ds: : Digital, Detailed and DisplayableDigital, Detailed and Displayable

TraditionalTraditional ProcessProcess

New Forecast ProcessNew Forecast Process

MARYLAND EASTERN SHORE

EASTON

PTCLDY CLOUDY PTCLDY PTCLDY SUNNY PTCLDY 60/52 63/54 65/47 55/40 55/37 50/33POP 20 POP 20 POP 20 POP 20 POP 10 POP 10



National Digital Forecast Database National Digital Forecast Database Gives Customers What They WantGives Customers What They Want

More weather More weather data data

Higher resolution Higher resolution forecastsforecasts

Visual displays of Visual displays of probabilityprobability

User-defined User-defined products create products create business business opportunitiesopportunities

Different Different Products for Products for

Different Different CustomersCustomers


The public, emergency The public, emergency managers and city managers and city planners use planners use Internet graphic Internet graphic products for detailed products for detailed forecastsforecasts

Commercial weather Commercial weather companies & emergency companies & emergency managers use grids to managers use grids to generate tailored generate tailored productsproducts

Radio stations & public Radio stations & public read text forecastsread text forecasts


Overview of Access MethodsOverview of Access Methods

Complete dataset in GRIB2 via FTP/HTTPComplete dataset in GRIB2 via FTP/HTTP

Selected datasets via Web Services.Selected datasets via Web Services.

Graphical and text products and services on Graphical and text products and services on NWS websitesNWS websites

File names/details available at: File names/details available at: http://http://www.nws.noaa.gov/ndfd/technical/technical.htmwww.nws.noaa.gov/ndfd/technical/technical.htm

Experimental services available nowExperimental services available now

http://www.nws.noaa.gov/ndfd/technical/technical.htm

http://www.nws.noaa.gov/ndfd/technical/technical.htm


1) Detailed Gridpoint forecasts

2) Traditional Text forecasts

3) General Digital Forecast

4) Graphical Digital Forecast

Digital ForecastsDigital Forecasts


NWS Detailed “Gridpoint” NWS Detailed “Gridpoint” ForecastsForecasts

• Click on a specific location on map and get a specific Click on a specific location on map and get a specific forecast for a 5 mile radius of that location. forecast for a 5 mile radius of that location. •Forecast temperature, snowfall amount, rainfall, fog Forecast temperature, snowfall amount, rainfall, fog amount differ between the hills and valleys.amount differ between the hills and valleys.

– Valleys often foggier and colder on clear, calm nights than Valleys often foggier and colder on clear, calm nights than the hills.the hills.

– More snow falls on the hills versus valleys.More snow falls on the hills versus valleys.– Afternoon temperatures colder on hills versus valleys.Afternoon temperatures colder on hills versus valleys.

•New “gridpoint” forecasts will reflect these New “gridpoint” forecasts will reflect these differences!!differences!!

Forecasts include: Forecasts include: – Text forecast out to 7 daysText forecast out to 7 days– Forecasts graphsForecasts graphs– Hourly tabular forecast informationHourly tabular forecast information


Hourly Weather GraphsHourly Weather Graphs


Traditional Text Forecasts still Traditional Text Forecasts still availableavailable


Graphical Zone ForecastsGraphical Zone Forecasts


Graphical Forecast MapsGraphical Forecast Maps


Daily High TemperaturesDaily High Temperatures


Wind ForecastsWind Forecasts


Cloud CoverCloud Cover


WeatherWeather


SnowfallSnowfall


Graphical Forecasts Graphical Forecasts NationalNational

don’t be surprised by the expected!

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