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Time to start a new thread. Sally updates will be here. 

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BULLETIN
Tropical Storm Sally Intermediate Advisory Number 4A...corrected
NWS National Hurricane Center Miami FL       AL192020
200 PM EDT Sat Sep 12 2020

Corrected header

  • DEPRESSION BECOMES A TROPICAL STORM...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...25.6N 81.6W
ABOUT 35 MI...60 KM SSE OF NAPLES FLORIDA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Watch is in effect for...
* Ochlockonee River to Okaloosa/Walton County Line

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area within the next 48 hours.

Interests elsewhere along the northern Gulf Coast should monitor the progress of this system. Tropical storm or hurricane watches, and storm surge watches, could be issued for a portion of that area 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 200 PM EDT (1800 UTC), the center of Tropical Storm Sally was located near latitude 25.6 North, longitude 81.6 West. The depression is moving toward the west near 7 mph (11 km/h), and a turn toward the west-northwest is expected later today or tonight. A west-northwestward or northwestward motion is then expected during the next couple of days.  On the forecast track, the center is forecast to move over the southeastern and eastern Gulf of Mexico later today and Sunday, and then move over the north-central Gulf of Mexico Sunday night and Monday.

Maximum sustained winds have increased near 40 mph (65 km/h) with higher gusts.  Additional strengthening is expected over the next couple of days, and Sally is forecast to become a hurricane by late Monday.

Tropical-storm-force winds extend outward up to 80 miles (130 km) south and southeast of the center, just to the south of the Florida Keys.

The estimated minimum central pressure is 1004 mb (29.65 inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Wind gusts to tropical-storm force are possible across the southern portion of the Florida peninsula today, especially over the Florida Keys. Tropical storm conditions are possible in the watch area in the Florida Panhandle by Sunday night.

RAINFALL:  Sally is expected to produce total rainfall of 3 to 6 inches with isolated 8 inch amounts over the Florida Keys through tonight with 2 to 4 inches and isolated maximum amounts of 6 inches across southern Florida and the western Florida coast to the Tampa Bay metro area.  This rainfall will produce flash and urban flooding across southern Florida and prolong high flows and ongoing minor flooding on rivers across Central Florida.

Sally is expected to produce through Tuesday rainfall of 3 to 6 inches with localized amounts of 8 inches along the Gulf Coast from the Florida Peninsula to southeast Louisiana and 2 to 4 inches farther inland over far southern Alabama, Mississippi and southeast Louisiana.  This is expected to be a slow-moving system that will likely continue to produce heavy rainfall and considerable flooding near the central Gulf Coast through the middle of next week. Flash, urban and rapid onset flooding along small streams and minor to isolated moderate flooding on rivers is likely.

SURF:  Swells are expected to spread northward along the west-central coast of Florida and the Florida Panhandle during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.  Please consult products from your local weather office.

TORNADOES: A tornado or two is possible today and tonight over southern Florida.


NEXT ADVISORY
-------------
Next complete advisory at 500 PM EDT.

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Do we have enough going on?

Oof. That 8" light brown is right over me.

Me too! I've got to say, I've lived in this area for 32 years now and have never seen flooding on a catastrophic scale. Just gonna keep my fingers crossed that the trend continues.

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TROPICAL STORM SALLY FORECAST/ADVISORY NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL192020
2100 UTC SAT SEP 12 2020 (5pm)

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A STORM SURGE WATCH IS IN EFFECT FROM

  • THE MOUTH OF THE MISSISSIPPI RIVER TO THE ALABAMA/FLORIDA BORDER...INCLUDING LAKE PONTCHARTRAIN...LAKE MAUREPAS...LAKE BORGNE...AND MOBILE BAY.

A HURRICANE WATCH IS IN EFFECT FROM

  • GRAND ISLE LOUISIANA TO THE ALABAMA/FLORIDA BORDER...INCLUDING LAKE PONTCHARTRAIN...LAKE MAUREPAS...AND METROPOLITAN NEW ORLEANS.

THE TROPICAL STORM WATCH HAS BEEN EXTENDED WESTWARD FROM

  • THE OKALOOSA/WALTON COUNTY LINE TO THE ALABAMA/FLORIDA BORDER.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A STORM SURGE WATCH IS IN EFFECT FOR...

  • * MOUTH OF THE MISSISSIPPI RIVER TO THE ALABAMA/FLORIDA BORDER
  • * LAKE PONTCHARTRAIN...LAKE MAUREPAS...AND LAKE BORGNE
  • * MOBILE BAY

A HURRICANE WATCH IS IN EFFECT FOR...

  • * GRAND ISLE LOUISIANA TO THE ALABAMA/FLORIDA BORDER
  • * LAKE PONTCHARTRAIN AND LAKE MAUREPAS INCLUDING METROPOLITAN NEW ORLEANS

A TROPICAL STORM WATCH IS IN EFFECT FOR...

  • * ALABAMA/FLORIDA BORDER TO OCHLOCKONEE RIVER FLORIDA

 

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5 pm Saturday Update

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BULLETIN
Tropical Storm Sally Advisory Number   5
NWS National Hurricane Center Miami FL       AL192020
500 PM EDT Sat Sep 12 2020

  • SALLY MOVING SLOWLY AWAY FROM EXTREME SOUTH FLORIDA
  • STORM SURGE AND HURRICANE WATCHES ISSUED FOR PORTIONS OF THE NORTHERN GULF COAST...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...25.7N 81.9W
ABOUT 30 MI...45 KM SSW OF NAPLES FLORIDA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

A Storm Surge Watch is in effect from the Mouth of the Mississippi
River to the Alabama/Florida Border, including Lake Pontchartrain,
Lake Maurepas, Lake Borgne, and Mobile Bay.

A Hurricane Watch is in effect from Grand Isle Louisiana to the
Alabama/Florida border, including Lake Pontchartrain, Lake
Maurepas, and metropolitan New Orleans.

The Tropical Storm watch has been extended westward from the
Okaloosa/Walton County Line to the Alabama/Florida Border.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Watch is in effect for...

  • * Mouth of the Mississippi River to the Alabama/Florida Border
  • * Lake Pontchartrain, Lake Maurepas, and Lake Borgne
  • * Mobile Bay

A Hurricane Watch is in effect for...

  • * Grand Isle Louisiana to the Alabama/Florida border
  • * Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans

A Tropical Storm Watch is in effect for...

  • * Alabama/Florida Border to Ochlockonee River Florida

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 within the next 48 hours.

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 500 PM EDT (2100 UTC), the center of Tropical Storm Sally was located near latitude 25.7 North, longitude 81.9 West.  Sally is moving toward the west near 7 mph (11 km/h), and a turn toward the  west-northwest is expected tonight.  A west-northwestward or northwestward motion is then expected during the next couple of days.  On the forecast track, the center is forecast to move over the southeastern and eastern Gulf of Mexico tonight and Sunday, and then move over the north-central Gulf of Mexico Sunday night and Monday.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Strengthening is expected over the next couple of days, and Sally is forecast to become a hurricane on Monday.

Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center.

The estimated minimum central pressure is 1004 mb (29.65 inches).


HAZARDS AFFECTING LAND
----------------------
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...

  • Mouth of the Mississippi River to Ocean Springs, MS including Lake Borgne...6-9 ft
  • Ocean Springs, MS to MS/AL Border...4-6 ft
  • MS/AL Border to AL/FL Border, including Mobile Bay...2-4 ft
  • Lake Pontchartrain and Lake Maurepas...2-4 ft
  • AL/FL Border to Chassahowitzka, FL, including Pensacola Bay, Choctawhatchee Bay, and Saint Andrew Bay...1-3 ft 

The deepest water will occur along the immediate coast near and to the right of the landfall location, where the surge will be accompanied by large and damaging 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.

WIND:  Hurricane conditions are possible within the hurricane watch area by early Tuesday, with tropical storm conditions possible within the watch area by Monday.

Wind gusts to tropical-storm force are possible across the southern portion of the Florida peninsula through this evening, especially over the Florida Keys.  

RAINFALL:  Sally is expected to produce additional rainfall amounts of 2 to 4 inches over southern Florida and the Florida Keys through tonight.  Rainfall amounts of 2 to 4 inches with isolated amounts of 6 inches are expected along the west coast of Florida through Sunday.  This rainfall will produce flash and urban flooding across southern Florida and prolong high flows and ongoing minor flooding on rivers across central Florida.

Sally is expected to produce rainfall amounts of 5 to 10 inches across the Florida Panhandle, and 6 to 12 inches with isolated amounts of 18 inches over the Central Gulf Coast from Sunday into the middle of next week.  Sally is expected to be a slow moving system that will continue to produce heavy rainfall and considerable flooding near the central Gulf Coast through the middle of next week. Flash, urban and rapid onset flooding along small streams and minor to moderate flooding on rivers is likely.

SURF:  Swells are expected to spread northward along the west-  central coast of Florida and reach the Florida Panhandle and the northern Gulf Coast during the next couple of days.  These  swells are likely to cause life-threatening surf and rip current conditions.  Please consult products from your local weather office.

TORNADOES:  A tornado or two is possible through tonight over south  Florida.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.
 

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5 AM Sunday Update

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BULLETIN
Tropical Storm Sally Advisory Number   7
NWS National Hurricane Center Miami FL       AL192020
500 AM EDT Sun Sep 13 2020

  • SALLY STRENGTHENING
  • HURRICANE AND STORM SURGE WARNINGS ISSUED FOR PORTIONS OF THE NORTHERN GULF COAST...


SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...27.0N 84.0W
ABOUT 115 MI...190 KM W OF PORT CHARLOTTE FLORIDA
ABOUT 345 MI...550 KM ESE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

A Storm Surge Warning has been issued from Port Fourchon Louisiana
to Mississippi/Alabama Border.

A Hurricane Warning has been issued from Grand Isle Louisiana
northeast to Ocean Springs Mississippi, including New Orleans, 
Lake Pontchartrain and Lake Maurepas.

A Hurricane Watch has been issued from east of Morgan City
Louisiana to west of Grand Isle.

A Tropical Storm Warning has been issued from east of Ocean Springs
Mississippi to Indian Pass Florida.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...

  • * Port Fourchon Louisiana to the Mississippi/Alabama Border
  • * Lake Pontchartrain, Lake Maurepas, and Lake Borgne

A Hurricane Warning is in effect for...

  • * Grand Isle Louisiana to Ocean Springs Mississippi
  • * Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans

A Storm Surge Watch is in effect for...

  • * Mississippi/Alabama Border to the Alabama/Florida Border

A Hurricane Watch is in effect for...
* East of Ocean Springs to the Alabama/Florida Border

A Tropical Storm Warning is in effect for...
* East of Ocean Springs to Indian Pass

A Tropical Storm Watch is in effect for...
* Indian Pass to Ochlockonee River Florida

A Storm Surge Warning means there is a danger of life-threatening 
inundation, from rising water moving inland from the coastline, 
during the next 36 hours in the indicated locations. For a depiction 
of areas at risk, please see the National Weather Service Storm 
Surge Watch/Warning Graphic, available at hurricanes.gov.  This is a 
life-threatening situation.  Persons located within these areas 
should take all necessary actions to protect life and property from 
rising water and the potential for other dangerous conditions.  
Promptly follow evacuation and other instructions from local 
officials.

A Hurricane Warning means that hurricane conditions are expected 
somewhere within the warning area.  A warning is typically issued 
36 hours before the anticipated first occurrence of 
tropical-storm-force winds, conditions that make outside 
preparations difficult or dangerous.  Preparations to protect life 
and property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

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 Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, in this case within 12 to 24 hours.

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 500 AM EDT (0900 UTC), the center of Tropical Storm Sally was located near latitude 27.0 North, longitude 84.0 West. Sally is 
moving toward the west-northwest near 13 mph (20 km/h), and a west-northwestward or northwestward motion is expected through Monday. A decrease in forward speed and a turn toward the north- northwest is forecast on Tuesday. On the forecast track, the center of Sally will move over the southeastern and eastern Gulf of Mexico today, move over the north-central Gulf of Mexico tonight and Monday, and approach the north-central Gulf Coast within the hurricane watch area late Monday and Tuesday.

Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 50 mph (85 km/h) with higher gusts.  Further strengthening is expected over the next couple of days, and Sally is forecast to become a hurricane on Monday, with some additional strengthening possible through early Tuesday.

Tropical-storm-force winds extend outward up to 90 miles (150 km)from the center.

The estimated minimum central pressure is 1001 mb (29.56 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Sally 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...

  • Mouth of the Mississippi River to Ocean Springs including Lake Borgne...7-11 ft
  • Port Fourchon to Mouth of the Mississippi River...4-7 ft
  • Ocean Springs to MS/AL Border...4-7 ft
  • Lake Pontchartrain and Lake Maurepas...4-6 ft
  • MS/AL Border to AL/FL Border including Mobile Bay...2-4 ft
  • AL/FL Border to Chassahowitzka including Pensacola Bay, 
  • Choctawhatchee Bay, and Saint Andrew Bay...1-3 ft

The deepest water will occur along the immediate coast near and to the right of the landfall location, where the surge will be
accompanied by large and damaging 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.

WIND:  Hurricane conditions are expected within the warning area starting late Monday, with hurricane conditions possible within the hurricane watch area by early Tuesday. Tropical storm conditions are possible within the watch area by Monday, and within the warning area late Monday.

RAINFALL:  Tropical Storm Sally is expected to produce additional rainfall amounts of 1 to 3 inches with isolated amounts of 6 inches across southern and central Florida through Monday. This rainfall will produce flash and urban flooding and prolong high flows and ongoing minor flooding on rivers across Central Florida.

Tropical Storm Sally is expected to produce rainfall amounts of 6 to 12 inches with isolated amounts of 20 inches over portions of the Central Gulf Coast between the western Florida Panhandle and far southeast Louisiana from Monday into the middle of the week. Rainfall of 4 to 8 inches is possible farther inland over portions of Mississippi and Alabama. Sally is expected to be a slow moving system resulting in significant flash flooding near the Central Gulf Coast through the middle of the week. Flash, urban and rapid onset flooding along small streams, and minor to isolated major flooding on rivers is likely. 

SURF:  Swells will spread northward along the west-central coast of Florida and reach the Florida Panhandle and the northern Gulf Coast during the next couple of days.  These swells are likely to cause life-threatening surf and rip current conditions.  Please consult products from your local weather office.
 

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While northwesterly shear has been affecting Sally, the global
models suggest that the shear will decrease later today as it moves
under a narrow ridge.  Models all respond to these changing
conditions by showing intensification, but they disagree on the rate
of change
.  It is an extremely tricky forecast because of how this
might happen close to landfall, but guidance is generally 5-10 kt
higher than the last cycle so the intensity forecast has been raised

by those amounts up through landfall.  It is worth noting that rapid
intensification is a possibility if the system develops a more solid
inner core on Monday, and stronger solutions like the HWRF model
can't be dismissed.

 

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As far as excessive rainfall goes...

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In terms of the latest model guidance, the GFS and to a lesser  extent the ECMWF are west with their QPF maxima compared to the official NHC track, whereas the CMC is east of the track with the highest totals across Alabama and the NAM farther south.  The 00Z UKMET appears to be the global model that is closest to the preferred track, and this also has support from the ensemble 
biased corrected model.  
The best estimate for expected rainfall during this period is in the 4 to 8 inch range with isolated totals to 14 inches.  It is worth noting that the UKMET, ECMWF, and the NAM are indicating 24-hour rainfall maxima in excess of 12 inches, but given uncertainty in the ultimate track of the storm by this time, the WPC QPF is remaining slightly lower than the model consensus.  If the models continue to show extreme rainfall amounts with future forecast cycles, then upward adjustments to the QPF would eventually be needed.  If westwards trends in the guidance continue, similar to what the ECMWF and GFS are indicating, a westward adjustment to the QPF max may become necessary in later updates.  

 

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