While not officially announced by the NHC, latest hurricane hunter reports show Isaac is now of suffcient strength to be Hurricane Isaac and I believe the 10 a.m. update will reflect that.
Isaac is headed toward the mouth of the Mississippi River and the coast of Louisiana with winds of 75 mph and is moving at 7 mph. Isaac's forward motion has slowed considerably since the 5 a.m. update which doesn't bode well for Louisiana at all. Isaac is currently located about 120 miles from the mouth of the Mississippi River, so at this pace, it won't make landfall for another 12 hours or so.
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 700 AM CDT...1200 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 27.8 NORTH...LONGITUDE 88.2 WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 7 MPH...11 KM/H...AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT DAY OR TWO WITH SOME FLUCTUATIONS IN FORWARD SPEED. ON THE FORECAST TRACK...THE CENTER WILL BE NEAR OR OVER THE LOUISANA COAST TONIGHT OR EARLY WEDNESDAY. MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/H...WITH HIGHER GUSTS. STRENGTHENING IS FORECAST...AND ISAAC IS LIKELY TO BECOME A HURRICANE LATER TODAY. ADDITIONAL STRENGTHENING IS FORECAST UNTIL THE CENTER MOVES INLAND. TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 205 MILES...335 KM FROM THE CENTER.
HAZARDS AFFECTING LAND
----------------------
STORM SURGE...THE COMBINATION OF A STORM SURGE AND THE TIDE WILL CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY RISING WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE GROUND IF THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE...
* SOUTHEAST LOUISIANA AND MISSISSIPPI...6 TO 12 FT
* ALABAMA...4 TO 8 FT
* SOUTH-CENTRAL LOUISIANA...3 TO 6 FT
* FLORIDA PANHANDLE...3 TO 6 FT
* FLORIDA WEST COAST INCLUDING APALACHEE BAY...1 TO 3 FT
THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF ONSHORE WINDS. SURGE-RELATED FLOODING DEPENDS ON THE RELATIVE TIMING OF THE SURGE AND THE TIDAL CYCLE...AND CAN VARY GREATLY OVER SHORT DISTANCES. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE SEE PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES.
WIND...
TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE NORTHERN GULF COAST IN THE HURRICANE WARNING AREA THIS MORNING...WITH HURRICANE CONDITIONS EXPECTED BY THIS AFTERNOON. TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD NORTHWARD INTO THE FLORIDA BIG BEND AREA AND THE FLORIDA PANHANDLE IN THE TROPICAL STORM WARNING AREA THIS MORNING. TROPICAL STORM CONDITIONS ARE EXPECTED WITHIN THE TROPICAL STORM WARNING AREA IN LOUISIANA BY TONIGHT. TROPICAL STORM CONDITIONS ARE POSSIBLE ON THE COAST OF SOUTHWESTERN LOUISIANA AND THE UPPER TEXAS COAST BY TONIGHT OR EARLY WEDNESDAY.
RAINFALL...
ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF 7 TO 14 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 20 INCHES...IN SOUTHEASTERN LOUISIANA...SOUTHERN MISSISSIPPI... SOUTHERN ALABAMA...AND THE EXTREME WESTERN FLORIDA PANHANDLE. THESE RAINS COULD RESULT IN SIGNIFICANT LOWLAND FLOODING. TORNADOES...TORNADOES MAY OCCUR ALONG THE NORTHERN GULF COAST TODAY. SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO AFFECT THE FLORIDA COASTLINE AND PORTIONS OF THE NORTHERN GULF COAST FOR THE NEXT DAY OR SO.
------------------------------------
For us, the main threat is going to be heavy rain. Here's the latest from the Hydrometeorological Prediction Center:
------------------------------------
CONVECTIVE CHANCES SHOULD INCREASE THIS PERIOD FROM NC SOUTHWARD INTO NORTHERN GA..SC AS COLD FRONT SLIPS SLOWLY SOUTHWARD ACROSS THE REGION AND INTERACTS WITH PLUME OF VERY HIGH PWS FEEDING NORTHWARD INTO THE BOUNDARY IN DEEP LAYERED CONFLUENT REGION BETWEEN ISAACS CIRCULATION AND WESTERN PERIPHERY OF WESTERN ATLANTIC RIDGE. WITH PWS EXPECTED TO EXCEED 2.25 INCHES AND MODELS SHOWING INCREASING RIGHT ENTRANCE REGION JET DYNAMICS THAT COULD BE ENHANCED BY OUTFLOW FROM ISAAC...FEEL POTENTIAL FOR SOME SLOW E/W TRAINING BANDS OF HEAVY RAIN WILL BE POSSIBLE..ESPECIALLY FROM NE GA EWD INTO SRN NC..WHERE GENERALLY 1 TO 2 INCH PLUS RAINS WILL BE POSSIBLE WITH ISOLATED HEAVIER AMOUNTS OVER 4 INCHES OR SO GIVEN TROPICAL AIRMASS.
-----------------------------------
The NWS here in Atlanta is calling for 2-4" of rain between now and Friday with some isolated areas receiving more. The first band of rain is located between Atlanta and Macon and moving north. 2" has already fallen in some of those areas with more to come. Precipital water values are in the 2.2"-2.3" range (notice how thick the air feels?) so when it does rain, it will be a tropical rain and it comes down hard and fast. Ponding on the roadways will be an issue. Our 3 hour flash Flood Guidance shows that we can get about 3" or so before flooding becomes an issue.
Coordinates: 28.4667N 86.7833W Acft. Static Air Press: 843.0 mb (~ 24.89 inHg) Acft. Geopotential Hgt: 1,479 meters (~ 4,852 feet) Extrap. Sfc. Press: 999.1 mb (~ 29.50 inHg) D-value: - Flt. Lvl. Wind (30s): From 168° at 81 knots (From the SSE at ~ 93.1 mph) Air Temp: 17.5°C (~ 63.5°F) Dew Pt: 13.4°C (~ 56.1°F) Peak (10s) Flt. Lvl. Wind: 83 knots (~ 95.4 mph) SFMR Peak (10s) Sfc. Wind: 49 knots (~ 56.3 mph) SFMR Rain Rate: 2 mm/hr (~ 0.08 in/hr) (*) Denotes suspect data
We are getting feeder bands of rain in the Atlanta metro area right now and this band might stall out of the area for a while this afternoon as it interacts with a stationary front located over north Georgia. Expect this rain to continue most of the afternoon. Rainfall amounts over Georgia have already exceeded 3" in some locations so please be careful when driving on the streets and roads.
NORTHWESTWARD... SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...28.1N 88.5W ABOUT 80 MI...125 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 165 MI...260 KM SE OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...976 MB...28.82 INCHES
HURRICANE ISAAC TROPICAL CYCLONE UPDATE NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012 1120 AM CDT TUE AUG 28 2012 ...RECONNAISSANCE DATA INDICATE ISAAC FINALLY ACHIEVES HURRICANE STATUS... REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT MAXIMUM WINDS ASSOCIATED WITH ISAAC HAVE INCREASED TO 75 MPH...120 KM/H. ON THIS BASIS...ISAAC IS BEING UPGRADED TO A HURRICANE. SUMMARY OF 1120 AM CDT...1620 UTC...INFORMATION ----------------------------------------------- LOCATION...28.1N 88.6W ABOUT 75 MI...115 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 160 MI...250 KM SE OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...975 MB...28.79 INCHES
Ocean Springs [Jackson Co, MS] public storm surge at 11:15 AM CDT -- member of the public reported water covering high school parking lot in ocean springs about one half mile inland. it was relayed to NWS New Orleans that it was south of the ocean springs airport. Pascagoula [Jackson Co, MS] emergency mngr reports storm surge at 11:15 AM CDT -- multiple streets in Pascagoula closed due to inundation from storm surge associated with hurricane Isaac. Local Storm Report by NWS LIX: Ocean Springs [Jackson Co, MS] emergency mngr storm report 11:15 AM CDT -- multiple streets in ocean springs closed due to inundation from storm surge associated with hurricane Isaac.
COUNTIES UNTIL 230 PM EDT... AT 129 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SHOWERS WITH HEAVY RAIN FROM MONROE TO MADISON...MOVING NORTH AT 15 MPH. RAINFALL AMOUNTS FROM ABOUT 1.5 INCHES NEAR MONROE TO AROUND 3 INCHES NEAR MADISON HAVE OCCURRED SINCE THIS MORNING. ADDITIONAL RAINFALL AMOUNTS OF AROUND 1 INCH CAN BE EXPECTED OVER WALTON COUNTY AND AROUND ONE HALF INCH OVER MORGAN COUNTY THIS AFTERNOON. THIS INCLUDES THE AREAS AROUND RUTLEDGE...HARD LABOR CREEK STATE PARK... WINDSOR...HERNDONVILLE...YOUTH...EBENEZER... WALNUT GROVE...SOCIAL CIRCLE...LOGANVILLE...JERSEY...BETWEEN... PANNELL...MONROE...BOSTWICK AND NICHOLASVILLE. DRIVERS SHOULD USE CAUTION AS INTENSE RAINFALL WILL REDUCE VISIBILITIES. TEMPORARY STREET FLOODING AND PONDING OF WATER ON ROADWAYS IS LIKELY.
JACKSON COUNTIES UNTIL 245 PM EDT... AT 141 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SHOWERS WITH HEAVY RAIN MOVING INTO OCONEE...BARROW AND JACKSON COUNTIES...MOVING NORTH AT 15 MPH. RAINFALL AMOUNTS OF AROUND ONE HALF INCH HAVE OCCURRED THIS AFTERNOON. ADDITIONAL RAINFALL AMOUNTS OF AROUND 2 INCHES CAN BE EXPECTED ACROSS OCONEE...BARROW AND JACKSON COUNTIES...
...HURRICANE ISAAC MOVING NORTHWESTWARD TOWARD THE MOUTH OF THE MISSISSIPPI RIVER...FLOODING FROM STORM SURGE AND RAINFALL EXPECTED... SUMMARY OF 100 PM CDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...28.4N 88.7W ABOUT 55 MI...85 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 135 MI...220 KM SE OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...975 MB...28.79 INCHES
LOUISIANA...FLOODING FROM STORM SURGE AND RAINFALL EXPECTED... SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...28.7N 89.2W ABOUT 30 MI...45 KM SSW OF THE MOUTH OF THE MISSISSIPPI RIVER ABOUT 105 MI...170 KM SSE OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...975 MB...28.79 INCHES
NOAA BUOY 42040...LOCATED EAST OF THE MOUTH OF THE MISSISSIPPI RIVER...RECENTLY MEASURED SUSTAINED WINDS OF 63 MPH...100 KM/H...AND A GUST TO 83 MPH. And from this buoy right at the mouth of the Mississippi NDBC Station KMIS 29.296 N 88.842 W 4:35 pm CDT 2135 GMT 08/28/2012 Wind: SSE (150°), 56.9 kt (65 mph) Gust: 92.1 kt (106 mph) Air Temp: 80.6 °F Dew Point: 77.0 °F Visibility: 0.2 nmi
http://www.ssec.wisc.edu/data/1min/index.php?action=view_animation&req_method=nframes_enddate&enddate=20120828&endtime=1803&nframes=200&band=1&res=1&aniwidth=null&aniheight=null Oh... this is pretty cool too http://www.ssec.wisc.edu/~rabin/goes14/loop_srso.html
STORM SURGE AND FLOOD THREAT FROM HEAVY RAINS LIKELY TO CONTINUE THROUGH TODAY AND TONIGHT... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...29.2N 90.5W ABOUT 30 MI...50 KM SSE OF HOUMA LOUISIANA ABOUT 60 MI...95 KM SSW OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...969 MB...28.61 INCHES Isaac has been sitting in roughly the same spot since late yesterday. This is going to be really bad for Louisiana.
----------------------------------------------- DURING THE PAST HOUR...A SUSTAINED WIND OF 54 MPH WITH A GUST TO 70 MPH WAS REPORTED AT LAKEFRONT AIRPORT IN NEW ORLEANS...A SUSTAINED WIND OF 46 MPH WITH A GUST TO 69 MPH WAS REPORTED AT NEW CANAL STATION IN NEW ORLEANS...AND A SUSTAINED WIND OF 58 MPH WITH A GUST TO 73 MPH WAS REPORTED AT SHELL BEACH LOUISIANA. RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF 7 TO 14 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 20 INCHES...OVER MUCH OF LOUISIANA...SOUTHERN MISSISSIPPI...AND SOUTHWEST ALABAMA THROUGH FRIDAY MORNING. THESE RAINS COULD RESULT IN SIGNIFICANT LOWLAND FLOODING. RAINS ARE EXPECTED TO INCREASE NORTHWARD INTO ARKANSAS ON THURSDAY WITH AMOUNTS OF 3 TO 6 INCHES EXPECTED OVER SOUTHERN ARKANSAS BY FRIDAY MORNING. --------------------------------------- Isaac right now is stationary and has been for the last 3 or 4 hours.
http://hint.fm/wind/
------------------------ ...ISAAC LASHING SOUTHEASTERN LOUISIANA WITH STRONG SQUALLS... DANGEROUS STORM SURGE AND FLOOD THREAT FROM HEAVY RAINS LIKELY TO CONTINUE THROUGH TODAY AND TONIGHT... SUMMARY OF 800 AM CDT...1300 UTC...INFORMATION ---------------------------------------------- LOCATION...29.5N 90.5W ABOUT 15 MI...20 KM ESE OF HOUMA LOUISIANA ABOUT 40 MI...70 KM SW OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...970 MB...28.64 INCHES
------------------------------------------- MAIN PROBLEM IN THE SHORT TERM IS COVERAGE AND TIMING OF SHRA/TSRA. RICH MOISTURE FROM ISAAC CONTINUES TO STREAM EAST FROM THE CENTER OVER THE STATE WITH WEAK FRONTAL ZONE OVER NORTH GA GOING NOWHERE FAST. VERY FAVORABLE WAA (Warm Air Advection) PATTERN IN LOW LEVELS WILL ALLOW FAIRLY WIDESPREAD SHRA WITH SOME TSRA TO DEVELOP BY MIDDAY. RAINFALL COULD BE HEAVY WHERE IT OCCURS BUT ACCUMULATIONS AT ANY ONE SPOT SHOULD REMAIN NO GREATER THAN AN INCH WITH LOCALLY HIGHER AMOUNTS. TOTAL RAINFALL THROUGH FRIDAY SHOULD NOT EXCEED TWO INCHES AT ANY ONE SPOT. MODELS IN PRETTY GOOD AGREEMENT ON COVERAGE TODAY. AFTER FAIRLY QUIET NIGHT WITH LOSS OF INSOLATION...SIMILAR PATTERN EXPECTED THURSDAY WITH RICH MOISTURE AND NEARBY FRONT.
WITH HEAVY RAIN...DANGEROUS COASTAL STORM SURGE AND INLAND FLOOD THREAT EXPECTED THROUGH TONIGHT... SUMMARY OF 1200 PM CDT...1700 UTC...INFORMATION ----------------------------------------------- LOCATION...29.7N 90.8W ABOUT 10 MI...15 KM NW OF HOUMA LOUISIANA ABOUT 45 MI...75 KM WSW OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...973 MB...28.73 INCHES
http://www.daculaweather.com/images/2012_08/st_145pm_wed.png
A SIGNIFICANT STORM SURGE... SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...30.1N 91.1W ABOUT 30 MI...50 KM S OF BATON ROUGE LOUISIANA ABOUT 60 MI...95 KM W OF NEW ORLEANS LOUISIANA MAXIMUM SUSTAINED WINDS...60 MPH...90 KM/H PRESENT MOVEMENT...NW OR 315 DEGREES AT 5 MPH...7 KM/H MINIMUM CENTRAL PRESSURE...977 MB...28.85 INCHES ----------------------------- New radar estimates of more than 16"+ http://www.daculaweather.com/images/2012_08/st_735pm_wed.png
I need an explanation, where is our weatherman? Is he still in Cornhusker land?
Isn't weather fun! Yes, Isaac made a big circle around a high pressure center and decided to plop back in the Gulf. And guess what? This is what we have now. TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012 500 PM EDT MON SEP 03 2012 THE SMALL LOW PRESSURE SYSTEM LOCATED OVER THE CENTRAL ATLANTIC...WHICH DEVELOPED FROM AN UPPER-LEVEL TROUGH...HAS GRADUALLY ACQUIRED ENOUGH ORGANIZED DEEP CONVECTION TO BE CLASSIFIED AS A TROPICAL DEPRESSION. VISIBLE SATELLITE IMAGERY AND AN EARLIER ASCAT PASS INDICATED THAT THE LOW HAS A WELL-DEFINED CENTER AND RELIABLE WINDS OF AROUND 25 KT. THE INITIAL INTENSITY IS SET A LITTLE HIGHER AT 30 KT SINCE ASCAT HAS A KNOWN LOW BIAS AND BECAUSE THE RESOLUTION OF THE INSTRUMENT LIKELY CAN NOT RESOLVE THE SMALL RADIUS OF MAXIMUM WINDS. THE DEPRESSION IS FORECAST TO MOVE SLOWLY WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN PORTION OF A RIDGE OVER THE EASTERN ATLANTIC DURING THE NEXT 24 HOURS. AFTER THAT TIME...THE CYCLONE IS EXPECTED TO TURN NORTHWARD AS THE WESTERN PORTION OF THE RIDGE ERODES.
I'm also a part of the Spotter Network. http://www.spotternetwork.org/ Their training is a little more rigorous than the NWS class and very thorough. If you liked the NWS training, I think you'll like this too.