Comparison of Tropical Comparison of Tropical Cyclones Cindy (2005) and Cyclones Cindy (2005) and

Ivan (2004)Ivan (2004)

By: Michael L. Jurewicz, Sr.By: Michael L. Jurewicz, Sr.Northeast Regional Operational Workshop Northeast Regional Operational Workshop

(NROW)(NROW)Albany, NYAlbany, NY

November 1-2, 2005November 1-2, 2005

Very Different Results for the Very Different Results for the Northeastern U.S.Northeastern U.S.

• Cindy: Little or no significant impactCindy: Little or no significant impact– Mainly 1-3” rainfall amounts (locally 4-5”) Mainly 1-3” rainfall amounts (locally 4-5”)

across the Delmarva Region, PA, NJ, and across the Delmarva Region, PA, NJ, and Eastern NY within a 24 hour period Eastern NY within a 24 hour period

– Dry antecedent conditions going into the eventDry antecedent conditions going into the event

• Ivan: Major impactIvan: Major impact– Widespread 4-7” (locally up to 10”) rainfall Widespread 4-7” (locally up to 10”) rainfall

amounts from the Ohio Valley / WV, across PA, amounts from the Ohio Valley / WV, across PA, Southern / Eastern NY, and Northern NJ in a 12-Southern / Eastern NY, and Northern NJ in a 12-18 hour period18 hour period

– Already wet heading into this event Already wet heading into this event

Ivan’s TrackIvan’s Track

Ivan Rainfall TotalsIvan Rainfall Totals

Localized Multi-Sensor Localized Multi-Sensor EstimatesEstimates

Cindy’s TrackCindy’s Track

Cindy Rainfall TotalsCindy Rainfall Totals

Storm Total Estimates from Storm Total Estimates from KBGM WSR-88DKBGM WSR-88D

Both Cyclones Acquired Similar Both Cyclones Acquired Similar Structures during their ETStructures during their ET

• Increased frontal-wave structure with Increased frontal-wave structure with latitude at the surfacelatitude at the surface

• Upper-level jet cores were enhanced Upper-level jet cores were enhanced poleward of the cyclones poleward of the cyclones – Due to warm outflow, rising upstream heights, Due to warm outflow, rising upstream heights,

increased shearincreased shear

• Bands of stratiform +RA developed Bands of stratiform +RA developed north/west of the cyclonenorth/west of the cyclone– Located where best combination of low-level Located where best combination of low-level

fgen and elevated instability existed fgen and elevated instability existed

Schematic from CSTAR Schematic from CSTAR ResearchResearch

Frontal-waves:Frontal-waves: Cindy Ivan Cindy Ivan

Upper-level Jets:Upper-level Jets: Cindy Ivan Cindy Ivan

Stratiform Heavy Rain Stratiform Heavy Rain BandsBands Cindy Ivan Cindy Ivan

FGEN and Banded Heavy FGEN and Banded Heavy RainfallRainfall Cindy Ivan Cindy Ivan

Why Such a Disparity in Why Such a Disparity in Rainfall ?Rainfall ?

• Contrast in degrees of interaction Contrast in degrees of interaction with the Westerlies with the Westerlies – Time of year played a roleTime of year played a role– Ultimately affected each cyclone’s Ultimately affected each cyclone’s

ability to transport deep moisture ability to transport deep moisture northwardnorthward•Could either enhance / mitigate rainfall Could either enhance / mitigate rainfall

efficiencyefficiency

Ivan and its Proximity to Mid-Ivan and its Proximity to Mid-level Short-wave level Short-wave

Energy (Frame #1)Energy (Frame #1)

Ivan (Frame #2)Ivan (Frame #2)

Ivan (Frame #3)Ivan (Frame #3)

Cindy and its Proximity to Mid-Cindy and its Proximity to Mid-level Short-wave level Short-wave

Energy (Frame #1)Energy (Frame #1)

Cindy (Frame #2)Cindy (Frame #2)

Upper-level Jets:Upper-level Jets: Cindy Ivan Cindy Ivan

Low-level Jets and Total PWLow-level Jets and Total PW Cindy Ivan Cindy Ivan

Radar Composite from IvanRadar Composite from Ivan

Temperature / RH Cross-Temperature / RH Cross-section and Sounding analysis section and Sounding analysis

(Ivan)(Ivan)

Warm Cloud Layer of 4+ km

Radar Composite from Radar Composite from CindyCindy

Temperature / RH Cross-Temperature / RH Cross-section and OKX Sounding section and OKX Sounding

analysis (Cindy)analysis (Cindy)

Warm Cloud Layer of 2.5 to 3

km

Warm Cloud Depth of 2.5 to 3 km

Consequences of Influx of Consequences of Influx of Tropical Air (or lack thereof)Tropical Air (or lack thereof)

• In the case of Ivan:In the case of Ivan:– Stronger Upper-level jet (around 160 kt) lead to Stronger Upper-level jet (around 160 kt) lead to

more pronounced lower-level response (850 more pronounced lower-level response (850 mb flow of 45-50 kt) and more backed flow into mb flow of 45-50 kt) and more backed flow into the jet-entrance regionthe jet-entrance region

– Higher PW air / elevated freezing levels were Higher PW air / elevated freezing levels were transported northward into regions affected by transported northward into regions affected by stratiform rain bandsstratiform rain bands• Greater Rainfall Efficiency / Accumulation Rates Greater Rainfall Efficiency / Accumulation Rates

resultedresulted

Consequences of Influx of Consequences of Influx of Tropical Air (or lack thereof) - Tropical Air (or lack thereof) -

ContinuedContinued• In the case of Cindy:In the case of Cindy:

– Relatively weaker Upper-level jet (around 90 Relatively weaker Upper-level jet (around 90 kt) lead to less pronounced lower-level kt) lead to less pronounced lower-level response (850 mb flow of 30-35 kt) and less response (850 mb flow of 30-35 kt) and less backing of the flow backing of the flow

– Highest PW air / freezing levels were thus Highest PW air / freezing levels were thus shunted northeastward off the Mid-Atlantic shunted northeastward off the Mid-Atlantic coast; never reaching areas of NY / PA / NJ coast; never reaching areas of NY / PA / NJ affected by stratiform rain bandsaffected by stratiform rain bands• Lack of Tropical Rainfall RatesLack of Tropical Rainfall Rates

ConclusionsConclusions

• Tropical cyclones Cindy (2005) and Ivan Tropical cyclones Cindy (2005) and Ivan (2004) had several common elements(2004) had several common elements– Fairly similar paths from the Gulf Coast region Fairly similar paths from the Gulf Coast region

to the Mid-Atlantic statesto the Mid-Atlantic states– They took on some of the same structures They took on some of the same structures

during their ETduring their ET• Frontal-wave appearance at the surfaceFrontal-wave appearance at the surface

• Enhanced upper-level jet cores poleward of the Enhanced upper-level jet cores poleward of the cyclonescyclones

• Banded heavy rainfall north/west of the cyclone Banded heavy rainfall north/west of the cyclone centers, within low-level fgen maxima centers, within low-level fgen maxima

Conclusions (Continued)Conclusions (Continued)

• Despite these similarities, rainfall and Despite these similarities, rainfall and subsequent impacts were far differentsubsequent impacts were far different– Accumulation efficiency much greater Accumulation efficiency much greater

with Ivan due to influx of tropical air / with Ivan due to influx of tropical air / rainfall ratesrainfall rates

– Tropical rain rates were never ingested Tropical rain rates were never ingested into the banded rainfall over NY / PA / NJ into the banded rainfall over NY / PA / NJ with Cindywith Cindy

In the Interest of Keeping Up In the Interest of Keeping Up with Current Events : A Quick with Current Events : A Quick

Look at KatrinaLook at Katrina• A Band of Heavy Rain occurred A Band of Heavy Rain occurred

generally along its track during ETgenerally along its track during ET– 3-6” (locally up to 8”) of rain fell from 3-6” (locally up to 8”) of rain fell from

the Ohio Valley to Upstate NY / Northern the Ohio Valley to Upstate NY / Northern VT / Parts of Southern Ontario and VT / Parts of Southern Ontario and Quebec within a 24 hour periodQuebec within a 24 hour period

Katrina’s TrackKatrina’s Track

Katrina’s RainfallKatrina’s Rainfall

Storm Total Estimates from Storm Total Estimates from KTYX WSR-88DKTYX WSR-88D

Surface AnalysisSurface Analysis

Upper-level JetUpper-level Jet

Mid-level Vorticity / PV Mid-level Vorticity / PV CouplingCoupling

Low-level Jet and Theta-ELow-level Jet and Theta-E

FGEN and Banded Heavy FGEN and Banded Heavy RainfallRainfall

Radar Composite from Radar Composite from KatrinaKatrina

Temperature / RH Cross-Temperature / RH Cross-section and Sounding analysis section and Sounding analysis

(ALY)(ALY)

Warm Cloud Layer of 3.5 to 4

km

Warm Cloud Depth of 3.5

to 4 km

Final ThoughtsFinal Thoughts

• Katrina was, perhaps, a moderate example of a Katrina was, perhaps, a moderate example of a +RA event associated with ET Transition over the +RA event associated with ET Transition over the Northeastern U.S. (in between Cindy and Ivan)Northeastern U.S. (in between Cindy and Ivan)– Decent Westerly interaction (Some PV coupling / well Decent Westerly interaction (Some PV coupling / well

developed jet circulation) with 120 kt / 40-50 kt upper developed jet circulation) with 120 kt / 40-50 kt upper and lower-level jet coresand lower-level jet cores• Polar jet not quite as far south, or as strong as was the case Polar jet not quite as far south, or as strong as was the case

with Ivan (late August vs. mid to late September)with Ivan (late August vs. mid to late September)– Allowed tropical air / rainfall rates to be ingested into Allowed tropical air / rainfall rates to be ingested into

regions affected by more persistent, stratiform type regions affected by more persistent, stratiform type banding banding • Rapid system movement / dry antecedent conditions Rapid system movement / dry antecedent conditions

prevented an excessive flooding event prevented an excessive flooding event

Future PossibilitiesFuture Possibilities

• Magnitude of Heavy Rainfall with Transitioning Magnitude of Heavy Rainfall with Transitioning Tropical Cyclones seems contingent on 3 main Tropical Cyclones seems contingent on 3 main factors :factors :– Strength of remnant cyclone itselfStrength of remnant cyclone itself– Strength of synoptic-scale fronts / jetsStrength of synoptic-scale fronts / jets– Degree of interaction between the above mentioned Degree of interaction between the above mentioned

systems systems

• Modulating factors for any given area : Modulating factors for any given area : – Warm cloud depth / rainfall efficiencyWarm cloud depth / rainfall efficiency– Progressiveness of overall system Progressiveness of overall system

• Is there a way to categorize / package all of this Is there a way to categorize / package all of this information to better inform / serve the public ??information to better inform / serve the public ??