St. Petersburg, FL...Mobile, AL...Clearwater, FL...Largo, FL...Palm Harbor, FL...
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk
Area (sq. mi.)
Some Larger Population Centers in Risk Area
St. Petersburg, FL...Clearwater, FL...Largo, FL...Palm Harbor, FL...Bradenton, FL...
SPC AC 221727
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1127 AM CST Tue Jan 22 2019
Valid 231200Z - 241200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY
AFTERNOON INTO WEDNESDAY NIGHT NEAR NORTHEASTERN GULF COASTAL
Strong storms may impact northeastern Gulf coastal areas Wednesday
afternoon through Wednesday night, perhaps accompanied by at least
some risk for severe weather.
Downstream of large-scale mid/upper ridging, which is forecast to
continue to build within the mid-latitude westerlies over the
eastern Pacific, models indicate that large-scale troughing will
continue to evolve over interior North America through this period.
This latter regime will include at least one impulse of Arctic
origins digging toward the central Canadian/U.S. border area, and
another of mid-latitude Pacific origins digging inland of the
Pacific Northwest coast into the Rockies.
Preceding these features, a pair of short waves (comprising
significant troughing now crossing portions of the central Plains
and southern Rockies) will remain progressive, turning northeastward
and eastward, across the Great Lakes into Quebec, and across the
lower Rio Grande Valley toward the Appalachians. The northern
impulse may be accompanied by appreciable deepening of the primary
associated surface cyclone, while the southern impulse supports
secondary surface frontal wave development to the lee of the
southern Appalachians late Wednesday through Wednesday night.
Within the evolving pre-frontal warm sector across the eastern Gulf
Coast states into the southern Mid Atlantic, southward through the
eastern Gulf of Mexico and Florida Peninsula, considerable
intensification of south to southwesterly lower/mid tropospheric
flow is forecast, including speeds on the order of 40-70+ kt at 850
With the mid-level thermal trough forecast to generally lag to the
west/northwest of the warm sector through the period, relatively
warm layers aloft, coupled with rather modest low-level moisture
return off a still modifying Gulf boundary layer, appears likely to
confine any appreciable boundary layer destabilization to the
eastern/northeastern Gulf of Mexico. However, guidance indicates
that surface dew point increases to the lower/mid 60s, accompanied
by weak boundary layer destabilization, is at least possible into at
least portions of northeastern Gulf coastal areas. There remains
some spread among the various model output concerning where, perhaps
as far west as southeastern Louisiana coastal areas by midday
Wednesday, and perhaps as far east as the Tampa Bay area by 09-12Z
Given at least weak boundary layer destabilization near/inland of
coastal areas, in the presence of strong low-level and deep layer
shear, the environment probably will become conducive to organized
severe weather potential, generally associated with convection
spreading inland off the Gulf of Mexico. This may include an
evolving pre-frontal squall line, perhaps preceded by isolated
discrete supercell development, accompanied by a risk for a tornado
or two, in addition to potentially damaging wind gusts.
...MAXIMUM RISK BY HAZARD...
Tornado: 2% - Marginal
Wind: 5% - Marginal
Hail: <5% - None
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z