Mobile, AL...Pensacola, FL...Panama City, FL...Ferry Pass, FL...Prichard, AL...
MARGINAL
12,059
543,202
Pascagoula, MS...Enterprise, AL...Moss Point, MS...
Probabilistic Tornado Graphic
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
5 %
11,842
1,449,362
Mobile, AL...Pensacola, FL...Panama City, FL...Ferry Pass, FL...Prichard, AL...
2 %
12,049
543,175
Pascagoula, MS...Enterprise, AL...Moss Point, MS...
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
5 %
23,812
1,958,186
Mobile, AL...Pensacola, FL...Panama City, FL...Ferry Pass, FL...Prichard, AL...
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
SPC AC 151250
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Tue Sep 15 2020
Valid 151300Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
SOUTHERN ALABAMA AND THE FLORIDA PANHANDLE...
...SUMMARY...
A few tornadoes may occur across portions of southern Alabama and
the Florida Panhandle through tonight, in association with Hurricane
Sally.
...Synopsis...
In mid/upper levels, ridging will continue to prevail over most of
the western CONUS, with the height axis extending from parts of NV
and UT to BC. Downstream, initially fairly flat, west-northwest
flow aloft gradually will assume broadly cyclonic curvature as a
series of shortwaves traverses the northern stream, and a major
cyclone digs southeastward from Nunavut to western Hudson Bay.
At the surface, 11Z analysis showed a diffuse cold frontal zone from
the lower Savannah River Valley area across northwestern GA and
northern/central AL, to north-central portions of LA, through a
frontal wave in north-central TX, southwestward to the Rio Grande
Valley between DRT-LRD. The front is expected to decelerate and
gradually lose definition along most of that length through the
period. Hurricane Sally (below) will be the most crucial feature
for this forecast.
...Central Gulf Coast -- Hurricane Sally...
The tornado threat will very slowly increase with time and northward
extent today and tonight. See SPC tornado watch 489 and related
mesoscale discussions for near-term details.
Streamlines and implied near-surface trajectories have been
persistently offshore and traveling through the northern part of
Sally's outer precip swath, substantially limiting destabilization
inland. This condition will continue, but also, erode from the
south slowly, as the offshore component gradually weakens and
surface winds become coast-parallel, then slightly onshore. Despite
that veering, low-level vector shear and hodograph size should
strengthen, especially in the watch area, as the more-intense winds
above the surface begin to spread overland. Gradual destabilization
along the immediate coast is expected through the day, ahead of a
long-lasting and prominent inner band of convection that has hosted
several persistent cells if varying magnitudes of horizontal
cyclonic shear. This regime will shift inland largely in step with
the very slow northward component of Sally's translation vector, but
also may expand somewhat late in the period (late tonight) near or
after landfall.
Please refer to the latest NHC advisories for the latest track/
intensity forecasts and tropical watch/warning information regarding
Sally.
..Edwards/Broyles.. 09/15/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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