Basic Meteorology for Emergency Managers:Proactive Decision-Support for Severe Weather Events

http://okfirst.ocs.ou.edu

Dr. Kevin Kloesel and Mr. Dale MorrisOklahoma Climatological Survey

University of OklahomaNorman, OK

1. Training and Decision-Support Program for Public Safety in Oklahoma (OK-FIRST)

2. Severe Weather Products Available Nationally

3. Training and Other Weather Data Resources

Goals Of This Presentation

• Improve communication with local NWS offices.• Anticipate NWS warnings for better implementation.• Eventually develop better decision-support systems.

What is OK-FIRST?

An initiative by OCS to develop an all-hazard decision-support system for Public Safety Agencies (Emergency Management, Fire, and Police).

Provides instruction on how to use and apply the weather data.

Provides access to customized environmental information and products:

Oklahoma Mesonet (115 station automated network)NEXRAD (~20 products from 15 radars + mosaics)National Weather Service text and graphic products

OK-F RST!1

OK-FIRST Decision-Support SystemInstructional material integrated into the decision-support pages aids interpretation of weather patterns and radarsignatures.

Radar-Derived Rainfall Accumulation

The OK-FIRST “Curriculum”A week-long computer literacy and data interpretation workshop held at the University of Oklahoma/Oklahoma Weather Center

Two-day “Assistant’s Workshops”

Two-day Refresher Courses

Combination of lecture materials and hands-on laboratory case-study exercises.

Completion of course provides an individual with certification to use the OK-FIRST system.

Often held regionally.Participants must attend at least one refresher every 18 months to maintain certification.

Basic meteorology, system usage, and severe weather concepts for other officials besides the certified participant.

Comprehensive glossary of weather terminology.

Learning modules for basic metr.

(e.g. fronts, seasons) Graphical examples of radar,

NWS, and surface map products.

Case studies of severe weather, flooding, and other events with online exercises and solutions.

One spotter was assigned to a location west of Moore. As the storms moved in, our spotter coordinator decided -- due to her OK-FIRST display -- to move the spotter a couple of miles south.

It was this spotter who gave us first knowledge of the large wall cloud that eventually spawned the tornado that destroyed/severely damaged a dozen homes and apartment buildings. The spotter’s call -- along with a warning from NWS Norman -- caused us to activate our warning system, and we provided our residents about 10 minutes of warning. There were NO injuries or fatalities from the storm.

The spotter later told us (numerous times) that had the EOC not moved him, he would not have been in the proper location to see the wall cloud!

This scenario is EXACTLY what OK-FIRST was designed to do! It certainly worked here!!!

— Gayland Kitch, City of Moore Emergency Management

Impacts in Local Communities

Lincoln County Emergency Management

Ben SpringfieldMay 3, 1999

Tanger Mall was cleared of people before the storm arrived.Rural citizens were informed by updates broadcast on scanner and took shelter.Patients at Stroud Hospital were moved into hallways before debris filled the rooms.

Impacts in Local Communities

Independent EvaluationEvaluator’s Summary Finding

“The project changed the behavior of local public safety officials and their approach to decision-making. OK-FIRST [has] had a positive influence on the types of decisions they make, how they make those decisions, and when they are willing to make those decisions. They are able to provide assistance to support a wide range of government and public service functions – from providing information to schedule public works projects to deciding to cancel the little league tournament scheduled for the weekend. Thus, the benefits that can accrue from the application of the skills developed through OK-FIRST can be far ranging and varied.”

— Dr. Thomas James, Institute for Public Affairs

Building OK-FIRST-like Systems in Your State

• Federal Grant Opportunities

• State Offices of Emergency Management, Departments of Public Safety

• Assistance from OK-FIRST

• Don’t forget to involve local NWS personnel (Warning Coordination Meteorologist)

Proactive Decision-Support for Severe Weather

• There are literally thousands of available weather products – results in bookmark clutter.

??

?What products do I use in what situation?

Proactive Decision-Support for Severe Weather

• Before the Event• The remainder of this talk

• During the Event• NWS Warnings & Severe Weather Statements• Radar Products

Tornadoes: Reflectivity, Storm-relative VelocityHail: Reflectivity, Vertically-Integrated LiquidWinds: Reflectivity, Velocity

• After the Event (documentation/training)• Local Storm Reports• Other databases, news reports, etc.• Archived warning/radar products

Before The Event Products

• Use for situational awareness

• Use to alert sister agencies for heads-up

• Use to pre-deploy resources

• Products issued from 7-10 days prior to the event to hours before the event.

U.S. Hazards Assessment

• NWS Climate Prediction Center (http://www.cpc.ncep.noaa.gov)

• 7-10 day outlook

• Issued weekly on Tuesdays

• Covers fire weather, winter weather, flooding, severe weather, and drought

Convective Outlooks

• NWS Storm Prediction Center (http://www.spc.noaa.gov)

• 1,2,3 day outlook

• Categorical and Probabilistic Outlooks

• Accompanying discussion

• Day 1 Outlook outlines areas for severe thunderstorm development 6 to 30 hour outlook

issued 5 times daily: 06Z (the initial Day-1 outlook, valid from 12Z to 12Z) 13Z and 16Z (the "morning updates," valid until 12Z)

20Z (the "afternoon update, " valid until 12Z)

01Z (the "evening update," valid until 12Z)

Convective Outlooks

• Day 2 Outlook issued twice daily: 08Z and 18Z valid for 24 hours beginning at 12Z the following day

• ¾” hail

• 50 knot (58 mph) wind

• tornado

What Makes Severe?

Convective Outlook Terminology

• Focused on the ingredients for severe weather• The stability/instability of the atmosphere• Mechanisms to release the instability • Mechanisms to generate upward motion

Atmospheric moisture + Atmospheric moisture + vertical motion = explosive vertical motion + Precipitation wind shear? = Severe Weather

Stability

• The tendency for air when slightly displaced vertically to return to its original position

• Related to the change of temperature with height (lapse rate) and warm air rising/cool air sinking

• Terms related to stability = CAPE, Cap, Lifted Index

Vertical Temperature Profiles

• Balloon observations

• Twice daily in the U.S.

• 0000 & 1200 UTC (6 AM/PM in winter) (7 AM/PM in summer)

Dew Point

DeepMoisture

Temperature

surface~5,000 ft

~18,000 ft

~30,000 ft

CAPE = 1207

CAPE = 2183

Lifted Index= -6

Sounding Indices

“Positive” Factors• CAPE = Convective Available Potential Energy

• Related to updraft strength

• CAPE above 1000 moderately unstable CAPE above 2500 very unstable CAPE above 3500 extremely unstable

• LI or LIFT = Lifted Index

• Somewhat crude method to measure instability (500 mb only)

• LI over 0 stable LI 0 to -3 marginal LI -3 to -6 moderate LI -6 to -9 very unstable LI below -9 extremely unstable

sfc

~5kft

~18kft

~30kft

CAPE = 1207

TemperatureInversion(T incr. w/ height)also known as Cap

SW WindsAir from Mexican Plateau

“~Negative” Factors

sfc

~5kft

~18kft

~30kft

Cap (Warm Air Aloft) 850 mb (~5,000 ft) temperature

Notice the “ridge” in the Central Plains and the “troughs” in the east and west. The trough is where you observe low 500mb heights (low thickness values and cold temps.). The ridge is where the highest thickness values (and highest temps.) are observed.

Ridges and Troughs

TROUGH‘TROF’ TROUGH

RIDGE

Experience and physics tells us we have cold (dense) air at the poles, and warm (less dense) air in the tropics.

Cold air takes up less space (more dense) than warm air.

The Earth is constantly trying to reach an equilibrium (moving warm air poleward and cold air equatorward).

Ever-changing ingredients stirred by troughs and ridges bring the changing weather conditions that we observe on Earth.

Ridges and Troughs

Air Mass Classification

Temp

Moisture

continental DRY

maritimeMOIST

polar or(arctic)COLD

tropicalWARM

cP (or cA)COLD & DRY

mP COLD & MOIST

cT WARM & DRY

mT WARM & MOIST

Air Mass Classification Based on temperature (cold/warm) and moisture

(moist/dry) characteristics of source region

Ridges, Troughs, Fronts:Why Do We Care?

Area between trough and downstream ridge is preferred area for large-scale rising motion

Ridges, Troughs, Fronts:Why Do We Care?

Surface winds converge

along/ahead of fronts/drylines= rising motion

OKZ039-044-045-TXZ086-089-090-081247-ARCHER TX-CLAY TX-COTTON OK-JEFFERSON OK-STEPHENS OK-WICHITA TX-INCLUDING THE CITIES OF...DUNCAN OK...WICHITA FALLS TX347 PM CDT SUN APR 7 2002

.TONIGHT...AN 80 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS. SOME THUNDERSTORMS MAY BE SEVERE. TEMPERATURES STEADY OR SLOWLY RISING INTO THE LOWER 60S. SOUTHEAST WINDS AROUND 15 MPH..MONDAY...MOSTLY CLOUDY WITH A 20 PERCENT CHANCE OF SHOWERS ANDTHUNDERSTORMS. HIGHS IN THE LOWER 70S. SOUTHWEST WINDS 10 TO 15 MPH..MONDAY NIGHT...MOSTLY CLOUDY. LOWS IN THE UPPER 40S. WEST WINDS 10TO 15 MPH BECOMING NORTH EARLY IN THE MORNING..TUESDAY...PARTLY CLOUDY. HIGHS IN THE UPPER 70S..TUESDAY NIGHT...MOSTLY CLEAR. LOWS IN THE MID 40S..WEDNESDAY...PARTLY CLOUDY. HIGHS IN THE MID 70S..THURSDAY...MOSTLY CLOUDY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS.LOWS IN THE LOWER 50S AND HIGHS IN THE MID 70S..FRIDAY...MOSTLY CLOUDY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS.LOWS IN THE MID 50S AND HIGHS NEAR 80..SATURDAY AND SUNDAY...PARTLY CLOUDY WITH A CHANCE OF SHOWERS ANDTHUNDERSTORMS. LOWS IN THE MID 50S AND HIGHS IN THE MID 70S.

$$

Zone Forecast

Good first look, but other products providemuch more specific information

AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE NORMAN OK342 PM CDT SUN APR 7 2002

SEVERE POTENTIAL...MAIN THREAT WILL BE S OF OUR CWA...BUT AREA SW OF KSPS IS ALSO A BIG CONCERN. IF SURFACE WARM FRONT AND ASSOCIATED CLEARING/ DESTABILIZATION IN WARM SECTOR PULL N INTO OUR TX ZONES...THREAT OF TORNADOES WILL INCREASE ACCORDINGLY. ALSO CONCERNED ABOUT HAIL THREAT FROM ELEVATED STORMS FARTHER NE INTO MUCH OF CWA THRU TONIGHT AS LL MOISTURE INCREASES BENEATH MID-LEVEL COOLING. CENTRAL OK PROGGED TO DESTABILIZE OVERNIGHT TO MUCAPES OF OVER 1200 J/KG. THEN THERE'S MONDAY. TIMING WILL BE CRITICAL...BUT IF ANY CLEARING/ HEATING OCCURS...AREAS E OF N-S SURFACE FRONT AND NE OF SURFACE LOW WILL DESTABILIZE ENOUGH FOR A THREAT OF COLD-CORE CONVECTION AND ASSOCIATED LARGE HAIL.

FLASH FLOODING...CURRENT PLAN IS TO CONTINUE WATCH TONIGHT IN SE AS IS. PRECIP HAS BEEN LIFTING N OF WATCH AREA TODAY BUT CONTINUES TO REDEVELOP S-WARD TO NEAR RED RIVER...IN AREA OF FAVORABLE WARM ADVECTION. THIS IS LIKELY TO CONTINUE OVERNIGHT...WITH GREATEST THREAT OF EXCESSIVE RAINFALL IN SATURATED AREAS OF SE OK.

Forecast Discussion

HAZARDOUS WEATHER OUTLOOKNATIONAL WEATHER SERVICE NORMAN OK1204 PM CDT SUN APR 7 2002

.THUNDERSTORM OUTLOOK...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOONAND TONIGHT FOR EXTREME SOUTHWEST PORTIONS OF WESTERN NORTH TEXAS.THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTOMONDAY MORNING ACROSS THE REMAINDER OF WESTERN NORTH TEXAS ANDPORTIONS OF WESTERN AND SOUTHERN OKLAHOMA.

.LOCATION...THE MODERATE RISK IS SOUTHWEST OF A LINE FROM CROWELL TO ARCHERCITY. THE SLIGHT RISK IS GENERALLY WEST AND SOUTH OF A LINE FROMALVA...TO CHICKASHA...TO MADILL.

.TIMING...ALTHOUGH THUNDERSTORMS ARE ALREADY OCCURRING...THE THREAT OF SEVERETHUNDERSTORMS IN THE MODERATE RISK AREA IS EXPECTED FROM AROUND 3 PMTHROUGH MID EVENING. IN THE SLIGHT RISK AREA THE THREAT OF SEVERETHUNDERSTORMS WILL EXIST THROUGHOUT THE REST OF THIS AFTERNOON ANDTONIGHT.

Hazardous Weather Outlook

.DISCUSSION...SHOWERS AND THUNDERSTORMS HAVE BEEN WIDESPREAD ACROSS OKLAHOMA ANDNORTH TEXAS THROUGH MUCH OF THE MORNING HOURS AND WILL PERSIST ACROSSPARTS OF THE AREA THROUGHOUT THIS AFTERNOON. THESE THUNDERSTORMS ANDTHE ASSOCIATED CLOUDINESS WILL CONTINUE TO KEEP THE AIRMASS COOL ANDRELATIVELY STABLE. HOWEVER...SKIES MAY PARTIALLY CLEAR LATER THISAFTERNOON ACROSS PORTIONS OF WESTERN AND SOUTHWESTERN OKLAHOMAAND WESTERN SECTIONS OF NORTH TEXAS. IF THIS CLEARING OCCURS...ADDITIONAL SURFACE HEATING COMBINED WITH INCREASING AMOUNTS OFLOW LEVEL MOISTURE WILL ALLOW THE ATMOSPHERE TO BECOME INCREASINGLYUNSTABLE...ESPECIALLY ACROSS THE MODERATE RISK AREA.

.OTHER HAZARDOUS WEATHER...HEAVY RAINFALL IS EXPECTED TO FALL SUNDAY AFTERNOON INTO MONDAYMORNING IN SOUTHEAST OKLAHOMA WHERE A FLASH FLOOD WATCH IS IN EFFECTTHROUGH TONIGHT. PLEASE REFER TO THE LATEST VERSION OF THIS PRODUCT/WGUS64 KOUN OR OKCFFAOKC/ FOR MORE INFORMATION REGARDING THE FLASHFLOOD THREAT.

Hazardous Weather Outlook

Mesoscale Convective Discussion

SPC MESOSCALE DISCUSSION 0324 FOR RED RIVER REGION OF OK/TXCONCERNING...SEVERE THUNDERSTORM POTENTIAL...

WW WILL LIKELY BE ISSUED SHORTLY FOR PORTIONS OF NORTH CENTRALTX/SRN OK ALONG THE RED RIVER.

PARTIAL CLEARING IS AIDING DESTABILIZATION NORTH OF SLOWLYRETREATING WARM FRONT ACROSS NORTH CENTRAL TX THIS AFTERNOON. SEVERE THUNDERSTORMS HAVE DEVELOPED ALONG/NORTH OF THE BOUNDARYFROM STONEWALL COUNTY TO THROCKMORTON COUNTY...WITH GRADUAL NWDDEVELOPMENT EXPECTED OVER THE NEXT FEW HOURS. THERE IS SOMECONCERN THAT NEAR SFC-BASED SUPERCELLS WILL SPREAD NORTH OF WARMFRONT WITH VERY LARGE HAIL...AND POSSIBLY A FEW TORNADOES. FARTHERNORTH INTO OK...ELEVATED INSTABILITY WILL INCREASE AHEAD OF LARGESCALE FORCING WITH LOW LEVEL WARM ADVECTION EXPECTED TO ENHANCEELEVATED DEEP CONVECTION/LARGE HAIL THREAT.

Surface Maps and Radar Reflectivity