Weekly Weather Briefing:Weekly Weather Briefing:IsaacIsaac

08/30/201208/30/2012

www.srh.noaa.gov/shv/briefingwww.srh.noaa.gov/shv/briefing

Brandi RichardsonBrandi RichardsonMeteorologistMeteorologist

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana

Preview Current ObservationsCurrent Observations

Center east of LaSalle ParishCenter east of LaSalle Parish Motion is north-northwestwardMotion is north-northwestward

Official Isaac ForecastOfficial Isaac Forecast Slightly east of Wednesday’s forecast trackSlightly east of Wednesday’s forecast track Becoming a Depression todayBecoming a Depression today Impacts looking more on the minimal sideImpacts looking more on the minimal side Model DataModel Data Several models still on a more westward trackSeveral models still on a more westward track

Needs to take a strong northwestward turnNeeds to take a strong northwestward turn

Through WednesdayThrough Wednesday

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana

Current ObservationsCurrent Observations

Power Outages

Numerous reports of

wind damage

Radar ImageryRadar Imagery

Observed RainfallObserved Rainfall

0.85

0.64

0.05

0.40

0.03

0.06

0.57

Official NHC Track ForecastOfficial NHC Track Forecast

Wednesday morning

Latest trackforecast(shifted

a hair eastward)

Official Rainfall ForecastOfficial Rainfall Forecast

Locally higher totals may be possible

3-5

”

2-3

”

1-2”

TodayToday

TonigTonightht

Official Forecast Official Forecast Impacts: Impacts: FloodingFlooding S AR, Extreme N Central LAS AR, Extreme N Central LA

Greatest risk for floodingGreatest risk for flooding Today PM-Fri AMToday PM-Fri AM

SW AR, Parts of NW LASW AR, Parts of NW LA De Queen/Nashville – De Queen/Nashville –

Bienville/JonesboroBienville/Jonesboro Today early PM-Fri AMToday early PM-Fri AM

Central LACentral LA Natchitoches/Coushatta – Natchitoches/Coushatta –

Columbia/JenaColumbia/Jena TodayToday

Flash

Flo

odin

g

Fla

sh F

loodin

g

Possib

le

Possib

le

Official Forecast Official Forecast Impacts: Impacts: WindsWinds1 PM 1 PM TodayToday Tropical Tropical

Storm force Storm force windswinds

N Central LA N Central LA ~35-40 mph~35-40 mph Today, Today,

decreasing this decreasing this afternoonafternoon

SW AR/SE OK SW AR/SE OK 25-30 mph25-30 mph TonightTonight

E TXE TX 20-25 mph 20-25 mph TodayToday

3 PM 3 PM TodayToday

Official Forecast Official Forecast Impacts: Impacts: TornadoesTornadoes

Thu AM – Fri AM

N Central N Central LA/S AR LA/S AR Most at riskMost at risk Quick spin-Quick spin-

upsups Not much Not much

lead timelead time

ElsewhereElsewhere Can’t rule it Can’t rule it

out, but very out, but very low risklow risk

Watches/Warnings/Watches/Warnings/AdvisoriesAdvisories

Flash Flood Flash Flood WatchWatch

Now - 7 Now - 7 PM PM

TonightTonight

Topical Topical Storm Storm

WarningWarningFlash Flood Flash Flood

WatchWatchNow - 7 PM Now - 7 PM

TonightTonight

UncertaintyUncertainty

Current Current motion motion makes makes

these model these model tracks less tracks less probableprobable

Still several Still several models models

indicating a indicating a move towards move towards

the NWthe NW

The Rest of the ForecastThe Rest of the Forecast

HH

7 PM Friday

The Rest of the ForecastThe Rest of the Forecast

HH7 PM Saturday

The Rest of the ForecastThe Rest of the Forecast

HH

1 PM Monday

Summary Current ObservationsCurrent Observations

Center just east of LaSalle ParishCenter just east of LaSalle Parish Three-hour motion is due-NThree-hour motion is due-N

Official Isaac ForecastOfficial Isaac Forecast Slightly east of Wednesday’s forecast trackSlightly east of Wednesday’s forecast track Becoming a Depression todayBecoming a Depression today Impacts looking more on the minimal sideImpacts looking more on the minimal side Model DataModel Data Several models still on a more westward trackSeveral models still on a more westward track

Needs to take a strong northwestward turn to verifyNeeds to take a strong northwestward turn to verify

Through WednesdayThrough Wednesday Ridge is squeezed southeastward around Isaac and Ridge is squeezed southeastward around Isaac and

back into the Desert SWback into the Desert SW Region remains under the influence of the ridgeRegion remains under the influence of the ridge

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana

NEXT CONFERENCE CALL:

Thursday September 6, 2012 @ 10 AMThursday September 6, 2012 @ 10 AM

www.srh.noaa.gov/shv/briefingwww.srh.noaa.gov/shv/briefing

National Weather Service Shreveport, LouisianaNational Weather Service Shreveport, Louisiana