Chapter 7- Synoptic climatology

Instantaneous climatological conditions

•a snap shot of what the climate is like at some point in time

Typically used in meteorological forecasting to show current weather conditions

Chapter 7- Synoptic climatology

Instantaneous climatological conditions

•a snap shot of what the climate is like at some point in time

Typically used in meteorological forecasting to show current weather conditions

Synoptic- Of or relating to meteorological or climatological data obtained nearly simultaneously over a relatively large area of the atmosphere.

Synoptic- Of or relating to meteorological or climatological data obtained nearly simultaneously over a relatively large area of the atmosphere.

Air mass locations, designations and tracks

Mid latitude cyclonic storm tracks

Cyclogenesis in the mid-latitudes

Cyclonic stormsCyclonic storms• • Associated with Low pressure systemsAssociated with Low pressure systems• • Lows moved by Upper level high velocity winds Lows moved by Upper level high velocity winds

- - JetstreamJetstream

• • usually involve air masses with different properties usually involve air masses with different properties - - one warm the other coldone warm the other cold- - one humid the other dryone humid the other dry

Cyclone (L)-Anticyclone (H) relationships to Upper Air flow and vertical motion

Fronts (1:2)Fronts (1:2)• • Transition zone between air massesTransition zone between air masses

• • Cold Front (can move very fast)Cold Front (can move very fast)- - colder air mass moving faster than warmer aircolder air mass moving faster than warmer air- - lifts warm air up in front of itlifts warm air up in front of it- - may form something called a "dry line"may form something called a "dry line"

> > associated with strong thunderstorm developmentassociated with strong thunderstorm development

- - described according to air mass which isdescribed according to air mass which isapproaching and relative motionapproaching and relative motion

• • Warm Front (typically moves more slowly)Warm Front (typically moves more slowly)- - warmer air mass moving faster than cooler airwarmer air mass moving faster than cooler air- - warm air rides up over cold dense airwarm air rides up over cold dense air- - usually a wider band of "active" weatherusually a wider band of "active" weather

Fronts (2:2)Fronts (2:2)

Sectors in mid-latitude cyclonic storms

Air sectors and air flow associated with a mid-latitude cyclonic storm from map view and 3D view

Air sectors and air flow associated with a mid-latitude cyclonic storm from map view and 3D view

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Factors influencing mid latitude cyclones

blocking highs- High pressure systems that do not move force other weather producing features like MLCS to be deflected around them or to stack up behind them

persistent jetstream patterns- these force MLCS to track over the same region over and over

Factors influencing mid latitude cyclones

blocking highs- High pressure systems that do not move force other weather producing features like MLCS to be deflected around them or to stack up behind them

persistent jetstream patterns- these force MLCS to track over the same region over and over

Case study- 1993 flooding in upper mid-West

Jetstream track was across the north central US

Multiple Mid-latitude Cyclones came through the upper midwest one right after another

Rossby waves in the Jetstream stood still, were not present, or were timed to coincide exactly with making the storms track across the upper midwest

Resulted in tremendous amounts of rainfall

Some locations received 250% of their annual precipitation in 4 months!

Case study- 1993 flooding in upper mid-West

Jetstream track was across the north central US

Multiple Mid-latitude Cyclones came through the upper midwest one right after another

Rossby waves in the Jetstream stood still, were not present, or were timed to coincide exactly with making the storms track across the upper midwest

Resulted in tremendous amounts of rainfall

Some locations received 250% of their annual precipitation in 4 months!

Synoptic set up of 1993 floods