# Presentation: 498637

## The Climate-Weather Link and U.S. Hazards PredictionByEd O’LenicNOAA-NWS-Climate Prediction CenterIAEM 50th Anniversary Conference and ExhibitColumbus Convention Center and Hyatt Regency HotelColumbus, OhioOctober 13, 2002

## Sources of Variability

- Tropical intra-seasonal oscillations (MJO)
- El Nino/Southern Oscillation (ENSO)
- Trend, Pacific Decadal Oscillation (PDO)

- Time Scales of Variability

-   Intra-Seasonal – within season
-   Inter-Annual – year-to-year
-   Decadal – decade-to-decade

## Solar radiation => Temperature gradients => Motions

- The sun is the source of all energy in the atmosphere-ocean-land system.
- The pole-to-equator temperature difference, created by sunshine heating the atmosphere-ocean-land system unevenly, drives large-scale atmospheric motions.
- Motions act to destroy temperature differences & balance in-coming vs. out-going radiation.
- Tropical disturbances, e.g., El Nino, La Nina, MJO, PDO are particularly effective at changing this large-scale difference, or _gradient _(difference/distance).
- This changes the location and strength of the major jet streams, which affects the weather.
- Temperature gradients also cause disturbances on smaller space and time scales, monsoons, cyclones, fronts, squall-lines, thunderstorms, clouds, etc...
- The oceanic circulation is important, too, but that’s a whole other lecture.

## Climate Versus Weather

- _Top Graph:_  Observed daily average
- Temperature (T), May 2000-April 2001
- (jagged curve, an example of  “weather”),
- and 30-year average (1971-2000) of daily
- average T (also called the “normal”,
- (smooth curve) the standard definition of
- “climate”) at Albany, New York.  Note the
- large day-to-day variability indicated by
- the red (above-normal) and blue (below
- normal) daily T events.
- _Bottom Graph:_  Result of subtracting
- the normal from the daily average T
- in the top graph and then performing a
- 31- day running average.  Note the
- expanded scale on the lower graph.
- The extended periods of above and below
- normal  31-day average T are, examples
- of short-term climate variability.  Green
- line is the average of the departures over
- May 2000-April 2001.

## Storms

-   LARGE-AMPLITUDE HORIZONTAL TEMPERATURE GRADIENTS IN MIDDLE LATITUDES (CYCLONES),
- 				OR
-   OCEAN SURFACE TEMPERATURES EXCEEDING
- 26 1⁄20 C AND WEAK LARGE-SCALE VERTICAL WIND SHEAR IN THE TROPICS AND SUB-TROPICS (TROPICAL STORMS).

## Coastal Population Rising

- The population in regions subject to strong coastal
- storms is rising rapidly.  Many of
- these people have
- little or no know-
- ledge of the
- potential for
- disaster in these
- areas.

## Insured Losses of U.S. Disasters, 1950-94

- Hurricanes and winter storms rank among the most expensive U.S. disasters

## The Great Snow and Wind Storm of Thanksgiving, 1950

- Unnamed wind storm:  November 23-December 2, 1950.  An intense, slow-moving extra-tropical storm along the U.S. East Coast was accompanied by sustained gale-force winds for several days, wind gusts to hurricane-force (including a gust to 110 mph on a sky scraper in New York City), wind-driven flooding near the coast (including 12 feet of flood water at La Guardia Airport), heavy snow in Western Pennsylvania.  East Coast and Great Lakes shipping was severely impacted.  Record low temperatures were observed in the South, including 3 degrees F at Atlanta, Georgia.  The insured loss from the storm was ~$6-7 B (in recent dollars).

## U.S. Hazards Assessmenthttp://www.cpc.ncep.noaa.gov/products/predictions/threats

**                          ****U.S. Hazards Assessment**
**Temperature/Wind                           Precipitation**

-    **Soil/Wildfire                                     Composite**

- U.S. Hazards Assessmenthttp://www.cpc.ncep.noaa.gov/products/predictions/threats

## U.S. Hazards Assessmenthttp://www.cpc.ncep.noaa.gov/products/predictions/threats

- A Hazards conference call is held each Wednesday at 2PM Eastern Time.

**Hazards Briefing Sequence**
**Satellite/Radar**
**IR Anim: **_[Global](http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ir_anim_monthly.html)_**, **_[North America](http://www.cpc.ncep.noaa.gov/products/precip/CWlink/na_new.html)_
- _[Water Vapor](http://www.cpc.ncep.noaa.gov/products/precip/CWlink/wv_anim_synoptic.html)__[ Anim](http://www.cpc.ncep.noaa.gov/products/precip/CWlink/wv_anim_synoptic.html)_
- _[US Radar](http://weather.noaa.gov/radar/mosaic/DS.p19r0/ar.us.conus.shtml)_
**Climate Monitoring**
**SST Anim: **_[Glbl](http://www.cpc.noaa.gov/products/analysis_monitoring/enso_update/gsstanim.html)_**, **_[Pac](http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.html)_**, **_[Atl](http://www.cpc.noaa.gov/products/hurricane/12wksst.html)__[/E Pac](http://www.cpc.noaa.gov/products/hurricane/12wksst.html)_
**7d SST: **_[Pac](http://www.cpc.ncep.noaa.gov/products/predictions/threats/briefs/brief01.html)_**, **_[Atl](http://www.cpc.noaa.gov/products/hurricane/atlsst_lastweek.html)__[/E Pac](http://www.cpc.noaa.gov/products/hurricane/atlsst_lastweek.html)_
- _[EQPAC T-Depth Plot](ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52yx/ocean/wkxzteq_last.html)_
**EQPAC T-Depth Anim: **_[Wk](ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52yx/ocean/wkxzteq.html)_**, **_[Mon](ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52yx/ocean/monxzteq.html)_
**Obs P: **_[1/7d](http://www.cpc.ncep.noaa.gov/products/precip/realtime/us_precip.html)_**, **_[30d](http://www.cpc.ncep.noaa.gov/products/predictions/threats/briefs/brief04.html)_**, **_[90d](http://www.cpc.ncep.noaa.gov/products/predictions/threats/briefs/brief05.html)_
**ENSO Bull: **_[Text](http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/)_**, **_[Fig 1](http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/advfig1.gif)_**, **_[Fig 2](http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/advfig2.gif)_
- _[Sea Level](ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52yx/ocean/monsl.html)__[ Anim](ftp://ftpprd.ncep.noaa.gov/pub/cpc/wd52yx/ocean/monsl.html)_
**Z Loops: **_[NH](http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_nh_anim.html)_**, **_[Globe](http://www.cpc.ncep.noaa.gov/products/intraseasonal/z200anim.html)_
- _[CDC OLR](http://www.cdc.noaa.gov/map/images/olr/olr.alt.anom.gif)__[ Anom](http://www.cdc.noaa.gov/map/images/olr/olr.alt.anom.gif)_
**Cities Temp**
**Cities Precip**
**Forecasts**
**NCEP Ensembles**
**NCEP Global Modeling Branch**
**CPC D+8 and Week 2 Forecasts**
**Long Range: Mon, Seas**
**Medium Range: 6-10 Day, 8-14 Day**
**Ensemble Spaghetti Charts**
**3-5 Day Prcp Prbs**
**3-5 Day Temp Fcst**
**Heat Index**
**Blocking: Obs & Fcsts**
**Predictability**
**Indices**

## Linkage between weather and climate

- Weather

- Short-term Climate
- Variability

- Decadal Climate
- Variability

- Trends of unknown origin, Trends in ENSO & AO, Global Warming, Thermohaline Circulation, Ultra-slow oscillations

- ENSO, MJO, PDO (tropics)                   AO, PNA, Storm Tracks, Droughts, ...(extra-Tropics)

- Jet streams, tropical storms, Extreme events, floods, diurnal cycle, ...

- Reacts to changes in heat budget
- through changes to planetary-scale
- temperature gradient, which affect
- weather.

- Reacts to changes in the
- global heat budget

- Reacts to changes in heat
- budget, temperature gradient.

**Notes:**
Weather, short-term climate variability and decadal climate variability all interact with each other.  

## El Niño / Southern Oscillation - ENSO

- El Nino _warms_ the global tropics, strengthening the pole-equator temperature difference.
- El Niño causes drought in normally wet regions and floods in normally dry regions.
- La Nina _cools_ the global tropics, weakening the pole-equator temperature difference.
- La Niña causes floods in normally wet regions, makes dry regions drier.

## El NINO/Southern Oscillation

## El Nino Global Precipitation Impacts

## ENSO Impacts

## U.S. ENSO Impacts

- ENSO Impacts illustrate the basis of the climate-weather link.

- El Nino 1997-98

## El Nino summer: Few Atlantic Storms

## La Nina summer: Many Atlantic Storms

## Observed and Annual Cycle of Precipitation near SFO

- El Nino-related
- Above normal
- rainfall

## The Madden-Julian Oscillation (MJO): A disturbance in tropical cloudiness, rainfall, wind and pressure

- Consists of a cloudy, rainy, strong low-level westerly wind phase and a non-cloudy, dry, low-level easterly wind phase.
- Move from eastward from the Indian Ocean around the globe in 30-60 days.  Disturbances are ~1500 km wide.
- Most active during ENSO-neutral years (especially just prior to El Niño).
- Affects the frequency of extreme weather events, such as floods, in winter, and tropical cyclones and monsoons, in summer.
- Low-level westerly wind bursts during cloudy phase warm the ocean, reverse easterlies, contribute to onset of El Nino.

## Intra-Seasonal Variability of Hurricanes Green~above-average cloudiness and rainfallBrown~below-average cloudiness and rainfall

- Intra-Seasonal Variability of Hurricanes Green~above-average cloudiness and rainfallBrown~below-average cloudiness and rainfall

- Madden-Julian Oscillations (MJO) – 30-60 day disturbances in tropical cloudiness

- Intra-Seasonal Variability of Hurricanes

## When the MJO maximum in tropical rainfall shifts eastward from Indonesia to the central tropical Pacific, the jet stream over the North Pacific gradually extends eastward towards the west coast of the U.S. and intensifies.  This pattern favors the occurrence of heavy precipitation events, along the Pacific Northwest coast.

## TROPICAL CYCLONES 

- Hurricane Floyd
- 2029 UT (0429 EST)
- Sep 14, 1999

## U.S. Hazards Assessment

## MAJOR REGIONS OF TROPICAL STORM ACTIVITY

## Atlantic Tropical Storm Climatology

## Eastern North Pacific Tropical Storm Climatology

## Atlantic Tropical Storms, 1967-2000

- Andrew

- Category 5

- Low numbers of
- storms does not imply
- weak storms

## Extra-Tropical Cyclones

- GOES water vapor 8.1 microns Feb 14, 2002

## North Atlantic Oscillation (NAO)

- The North Atlantic Oscillation is the pattern most-closely associated with _winter_ weather over North America, the Atlantic and Europe.  The pattern at right shows how the pattern differs from the 30-year average.  Red is for abnormally high pressure, blue is for abnormally low pressure.  The pattern shown is the _positive_ phase.  The reverse pattern is the _negative_ phase.

## NAO Phases/Impacts

## NAO Index, Monthly Mean, 1950-2002

## AO-ENSO Relationships –JFM Temperature Anomaly (0C) by AO and ENSO Phase

## Global Temperature Trends

## IPCC Estimate of Impact of Global Warming on Storm Activity

## Summary

- Climate = average of weather but controls “statistics” of weather.  This is the basis of the climate-weather link.
- U.S. Hazards Assessment emphasizes C-W Link.
- Tropical disturbances, MJO, ENSO cause much of the observed intra-seasonal to inter-annual variability in storms in low and middle latitudes.
- MJO is related to intense rain events in NW U.S.
- El Nino brings enhanced storminess and damage to the California coast.
- Tropical storm frequency shows large variability on decadal and longer time scales.
- - AO phase is related to strong U.S. winter cyclones.
- IPCC estimates storm strength and frequency will rise.
- 	http://www.wmo.ch/index-en.html