550  
WTNT34 KNHC 071453  
TCPAT4  
 
BULLETIN  
TROPICAL STORM ISAIAS ADVISORY NUMBER 4  
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092026  
1000 AM CDT WED OCT 07 2026  
 
...HURRICANE AND STORM SURGE WATCHES ISSUED FOR PORTIONS OF THE  
NORTHERN GULF COAST FOR STRENGTHENING ISAIAS...  
 
 
SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION  
-----------------------------------------------  
LOCATION...22.4N 93.6W  
ABOUT 260 MI...420 KM WNW OF PROGRESO MEXICO  
ABOUT 540 MI...870 KM SSW OF THE MOUTH OF THE MISSISSIPPI RIVER  
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H  
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 8 MPH...13 KM/H  
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES  
 
 
WATCHES AND WARNINGS  
--------------------  
CHANGES WITH THIS ADVISORY:  
 
A STORM SURGE WATCH HAS BEEN ISSUED FROM THE MOUTH OF THE  
MISSISSIPPI RIVER EASTWARD TO YANKEETOWN, FLORIDA.  
 
A HURRICANE WATCH HAS BEEN ISSUED FOR THE NORTHERN GULF COAST FROM  
BAY ST. LOUIS, MISSISSIPPI TO INDIAN PASS, FLORIDA.  
 
A TROPICAL STORM WATCH HAS BEEN ISSUED FOR THE NORTHERN GULF COAST  
FROM THE JEFFERSON/PLAQUEMINES PARISH LINE, LOUISIANA TO WEST  
OF BAY ST. LOUIS, AND FROM EAST OF INDIAN PASS TO AUCILLA RIVER,  
FLORIDA.  
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:  
 
A STORM SURGE WATCH IS IN EFFECT FOR...  
* MOUTH OF THE MISSISSIPPI RIVER TO YANKEETOWN  
 
A HURRICANE WATCH IS IN EFFECT FOR...  
* BAY ST. LOUIS TO INDIAN PASS  
 
A TROPICAL STORM WATCH IS IN EFFECT FOR...  
* JEFFERSON/PLAQUEMINES PARISH LINE TO WEST OF BAY ST. LOUIS  
* EAST OF INDIAN PASS TO AUCILLA RIVER  
 
A STORM SURGE WATCH MEANS THERE IS A POSSIBILITY OF LIFE-  
THREATENING INUNDATION, FROM RISING WATER MOVING INLAND FROM THE  
COASTLINE, IN THE INDICATED LOCATIONS DURING THE NEXT 48 HOURS.  
FOR A DEPICTION OF AREAS AT RISK, PLEASE SEE THE NATIONAL WEATHER  
SERVICE STORM SURGE WATCH/WARNING GRAPHIC, AVAILABLE AT  
HURRICANES.GOV.  
 
A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE  
WITHIN THE WATCH AREA. A WATCH IS TYPICALLY ISSUED 48 HOURS  
BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE  
WINDS, CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR  
DANGEROUS.  
 
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE  
POSSIBLE WITHIN THE WATCH AREA, GENERALLY WITHIN 48 HOURS.  
 
INTERESTS IN THE YUCATAN PENINSULA OF MEXICO AND ELSEWHERE  
AROUND THE U.S. NORTHERN GULF COAST SHOULD CLOSELY MONITOR THE  
PROGRESS OF THIS SYSTEM.  
 
ADDITIONAL WATCHES AND WARNINGS COULD BE REQUIRED FOR A PORTION OF  
THE U.S. NORTHERN GULF COAST LATER TODAY.  
 
FOR STORM INFORMATION SPECIFIC TO YOUR AREA, INCLUDING POSSIBLE  
INLAND WATCHES AND WARNINGS, PLEASE MONITOR PRODUCTS ISSUED BY YOUR  
LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.  
 
 
DISCUSSION AND OUTLOOK  
----------------------  
AT 1000 AM CDT (1500 UTC), THE CENTER OF TROPICAL STORM ISAIAS WAS  
LOCATED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT NEAR  
LATITUDE 22.4 NORTH, LONGITUDE 93.6 WEST. ISAIAS IS MOVING TOWARD  
THE EAST-NORTHEAST NEAR 8 MPH (13 KM/H). A CONTINUED  
EAST-NORTHEASTWARD MOTION IS EXPECTED TODAY, FOLLOWED BY A TURN  
TOWARD THE NORTHEAST AND NORTH ON THURSDAY AND FRIDAY. ON THE  
FORECAST TRACK, ISAIAS IS EXPECTED TO PASS TO THE NORTH OF THE  
YUCATAN PENINSULA ON THURSDAY AND APPROACH THE U.S. NORTHERN GULF  
COAST ON FRIDAY.  
 
MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 45 MPH (75 KM/H)  
WITH HIGHER GUSTS. RAPID STRENGTHENING IS FORECAST OVER THE NEXT DAY  
OR TWO, AND ISAIAS IS EXPECTED TO BECOME A HURRICANE BY THURSDAY.  
 
TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 45 MILES (75 KM)  
FROM THE CENTER.  
 
THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB (29.53 INCHES)  
BASED ON AIR FORCE DROPSONDE DATA.  
 
 
HAZARDS AFFECTING LAND  
----------------------  
KEY MESSAGES FOR ISAIAS CAN BE FOUND IN THE TROPICAL CYCLONE  
DISCUSSION UNDER AWIPS HEADER MIATCDAT4 AND WMO HEADER WTNT44 KNHC.  
 
STORM SURGE: THE COMBINATION OF A DANGEROUS STORM SURGE AND THE  
TIDE WILL CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY  
RISING WATERS MOVING INLAND FROM THE SHORELINE. THE WATER COULD  
REACH THE FOLLOWING HEIGHTS ABOVE GROUND SOMEWHERE IN THE INDICATED  
AREAS IF THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE...  
 
OCEAN SPRINGS, MS TO INDIAN PASS, FL...5-7 FT  
MOBILE BAY...5-7 FT  
MOUTH OF THE MISSISSIPPI RIVER, LA TO OCEAN SPRINGS, MS...3-5 FT  
INDIAN PASS, FL TO AUCILLA RIVER, FL...3-5 FT  
AUCILLA RIVER, FL TO YANKEETOWN, FL...2-4 FT  
LAKE PONTCHARTRAIN...1-3 FT  
 
THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST NEAR AND TO  
THE EAST OF THE LANDFALL LOCATION, WHERE THE SURGE WILL BE  
ACCOMPANIED BY LARGE AND DANGEROUS WAVES. 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  
NATIONAL WEATHER SERVICE FORECAST OFFICE.  
 
FOR A COMPLETE DEPICTION OF AREAS AT RISK OF STORM SURGE  
INUNDATION, PLEASE SEE THE NATIONAL WEATHER SERVICE PEAK  
STORM SURGE GRAPHIC, AVAILABLE AT  
HURRICANES.GOV/GRAPHICS_AT4.SHTML?PEAKSURGE.  
 
WIND: HURRICANE CONDITIONS COULD BEGIN IN THE HURRICANE WATCH AREA  
LATE FRIDAY, AND TROPICAL STORM CONDITIONS COULD BEGIN IN THE  
WATCHES AREAS MIDDAY FRIDAY.  
 
GUSTY WINDS ARE POSSIBLE IN PORTIONS OF THE YUCATAN PENINSULA  
ON THURSDAY.  
 
RAINFALL: TROPICAL STORM ISAIAS IS EXPECTED TO PRODUCE RAINFALL  
AMOUNTS OF 2 TO 4 INCHES THROUGH THURSDAY ACROSS COASTAL PORTIONS OF  
THE BAY OF CAMPECHE WITH ISOLATED HIGHER AMOUNTS POSSIBLE IN THE  
STATES OF CAMPECHE AND WESTERN YUCATAN.  
 
FROM FRIDAY THROUGH THE WEEKEND, THE SYSTEM IS EXPECTED TO PRODUCE  
RAINFALL AMOUNTS OF 3 TO 6 INCHES, WITH LOCALIZED TOTALS UP TO 10  
INCHES, ACROSS THE CENTRAL U.S. GULF COAST EXTENDING FROM FAR  
SOUTHEASTERN LOUISIANA TO THE FLORIDA PANHANDLE. RAINFALL AMOUNTS OF  
1 TO 3 INCHES, WITH LOCALIZED AMOUNTS UP TO 5 INCHES, ARE POSSIBLE  
ACROSS MUCH OF THE SOUTHEAST AS FAR NORTH AS THE TENNESSEE VALLEY  
AND THE CAROLINAS. FLASH AND URBAN FLOODING, ALONG WITH ISOLATED  
RIVER FLOODING, WILL BE POSSIBLE.  
 
FOR A COMPLETE DEPICTION OF FORECAST RAINFALL ASSOCIATED WITH  
TROPICAL STORM ISAIAS, PLEASE SEE THE NATIONAL WEATHER SERVICE STORM  
TOTAL RAINFALL GRAPHIC AVAILABLE AT  
HURRICANES.GOV/GRAPHICS_AT4.SHTML?RAINQPF AND THE FLASH FLOOD RISK  
GRAPHIC AT HURRICANES.GOV/GRAPHICS_AT4.SHTML?ERO  
 
SURF: SWELLS ARE EXPECTED TO AFFECT THE WESTERN AND NORTHERN  
PORTIONS OF THE YUCATAN PENINSULA BEGINNING ON THURSDAY AND SPREAD  
NORTHWARD TOWARD THE GULF COAST LATE THIS WEEK. THESE SWELLS ARE  
LIKELY TO CAUSE LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS.  
PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE.  
 
A DEPICTION OF RIP CURRENT RISK FOR THE UNITED STATES CAN BE FOUND  
AT: HURRICANES.GOV/GRAPHICS_AT4.SHTML?RIPCURRENTS  
 
 
NEXT ADVISORY  
-------------  
NEXT INTERMEDIATE ADVISORY AT 100 PM CDT.  
NEXT COMPLETE ADVISORY AT 400 PM CDT.  
 

 
FORECASTER BLAKE  
 
 
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