9/16/20 Early AM update: Sally close to landfall geographically, but not temporally, NHC increases intensity

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Hurricane Sally continues to defy all odds and rapidly intensify under the most unlikely of situations. The storm did finally reduce the dry air entrainment, but it is sitting over not-as-warm-as-earlier waters that are also more shallow, and can be cooled easier by rain and wind. And it is doing so in an atmospheric environment with more shear now than at any point during the past 36 hours.

It is 2020ing its heart out right now.




The latest from the NHC

SUMMARY OF 130 AM CDT

LOCATION…29.9N 87.8W
ABOUT 60 MI…95 KM SSE OF MOBILE ALABAMA
ABOUT 55 MI…90 KM SW OF PENSACOLA FLORIDA
MAXIMUM SUSTAINED WINDS…105 MPH…165 KM/H
PRESENT MOVEMENT…NNE OR 30 DEGREES AT 2 MPH…4 KM/H
MINIMUM CENTRAL PRESSURE…968 MB…28.59 INCHES
EYE DIAMETER 30 NM
64 KT……. 35NE 20SE 0SW 25NW.
50 KT……. 70NE 40SE 30SW 50NW.
34 KT…….110NE 110SE 80SW 80NW.
12 FT SEAS..120NE 120SE 90SW 90NW.

FORECAST MAP




DISCUSSION AND OUTLOOK

At 130 AM CDT (0630 UTC), the center of Hurricane Sally was located an Air Force Reserve Hurricane Hunter aircraft and NOAA Doppler weather radars near latitude 29.9 North, longitude 87.8 West. Sally is moving toward the north-northeast near 2 mph (4 km/h). A north-northeastward to northeastward motion at a slightly faster forward speed is expected later today and tonight, followed by a faster northeastward motion on Thursday. On the forecast track, the center of Sally will approach the northern Gulf Coast this morning, and make landfall in the hurricane warning area later today. Sally is then expected to move inland across southeastern Alabama tonight.

Recent data from An Air Force Reserve reconnaissance aircraft and the Mobile Alabama Doppler weather radar indicate that Maximum sustained winds have increased to near 105 mph (165 km/h) with higher gusts. Some further strengthening is possible before Sally makes landfall. Rapid weakening is expected after landfall occurs.

Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). A sustained wind of 81 mph (130 km/h) with a gust to 110 mph (178 km/h) was recently reported in Sally’s northern eyewall by NOAA buoy 42012, located about 50 miles southeast of Mobile, Alabama. A sustained wind of 72 mph (117 km/h) and a gust to 90 mph (144 km/h) were recently measured by the NOAA C-MAN observing station on Dauphin Island, Alabama.

The minimum central pressure recently reported by the Hurricane Hunters was 968 mb (28.58 inches).

HAZARDS AFFECTING LAND

RAINFALL: Sally is forecast to produce 10 to 20 inches of rainfall with isolated amounts of 30 inches along and just inland of the central Gulf Coast from the Florida Panhandle west of the Apalachicola River to the Alabama/Mississippi border. Historic, life-threatening flash flooding is likely. In addition, this rainfall will lead to widespread moderate to major flooding on area rivers.

Sally is forecast to turn inland today and track across the Southeast producing rainfall of 4 to 8 inches, with isolated maximum amounts of 12 inches, across portions of southeastern Mississippi, southern and central Alabama, central and northern Georgia, and the western Carolinas. Significant flash and urban flooding is likely, as well as widespread minor to moderate flooding on some rivers.

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…

Dauphin Island AL to Okaloosa/Walton County FL Line…4-7 ft
Pensacola Bay and Choctawhatchee Bay FL…4-7 ft
Mobile Bay…3-5 ft
Okaloosa/Walton County Line to Walton/Bay County line FL…2-4 ft
Mouth of the Mississippi River to MS/AL Border including
Lakes Pontchartrain, Maurepas and Borgne…1-3 ft
MS/AL Border to Dauphin Island AL…2-4 ft
Walton/Bay County line to Chassahowitzka FL including Saint Andrew
Bay…1-3 ft

The deepest water will occur along the immediate coast in areas of onshore winds, 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 spreading onshore within the hurricane warning area in Florida and Alabama. Tropical storm conditions will continue in portions of the warning areas through tonight.

TORNADOES: A few tornadoes may occur through today across portions of the Florida Panhandle and southern Alabama.

SURF: Swells from Sally will continue to affect the coast from the Florida Big Bend westward to southeastern Louisiana 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.




TECHNICAL DISCUSSION

Observations from an Air Force Hurricane Hunter aircraft and WSR-88D Doppler radar data indicate some strengthening. The eye has become a little better defined on the radar, and the central pressure has fallen to 972 mb. The eye has also become evident on recent IR imagery. Using a blend of flight-level and SFMR-observed surface winds, along with the Doppler velocities, gives a current intensity estimate of 75 kt. Given the recent trends, the official forecast allows for some more intensification
before landfall, which is likely to occur in less than 12 hours. Rapid weakening will occur after the center moves inland, and the system should become a remnant low in a couple of days. This is consistent with the model guidance.

Radar and aircraft center fixes indicate that the motion is now north-northeastward, or 020/2 kt. Sally should move north-northeastward, and then northeastward, with a gradual increase in forward speed, along the northwestern side of a weak mid-level high pressure area for the next couple of days. Then, as the system approaches the westerly flow at higher latitudes, the cyclone should turn toward the east-northeast with a slight further increase in forward speed until becoming a dissipating remnant low
near the southeast U.S. coast in 2-3 days. The official forecast is close to the latest corrected dynamical model consensus, HCCA, prediction.

KEY MESSAGES

1. Historic, life-threatening flash flooding due to rainfall is likely through Wednesday along and just inland of the coast from the Florida Panhandle west of the Apalachicola River to the Alabama/Mississippi border. Widespread moderate to major river flooding is forecast across the Florida Panhandle and southern Alabama. Significant flash and urban flooding, as well as widespread minor to moderate river flooding, is likely across inland portions of Mississippi and Alabama, and into Georgia and the western Carolinas this week.

2. Life-threatening storm surge is expected along portions of the coastline from Alabama to the western Florida Panhandle, including Mobile Bay.

3. Hurricane conditions are expected this evening and overnight within portions of the Hurricane Warning area along the Mississippi and Alabama coastlines and the western Florida Panhandle.




Live camera on the coast in Gulf Shores

“LIVE from The Beach Club Resort & Spa!” on youtube. Located:

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It looks like the stream recently died…. Likely due to power loss.



Author of the article:


Nick Lilja

Nick is former television meteorologist with stints in Amarillo and Hattiesburg. During his time in Hattiesburg, he was also an adjunct professor at the University of Southern Mississippi. He is a graduate of both Oregon State and Syracuse University that now calls Houston home. Now that he is retired from TV, he maintains this blog in his spare time.