Windy.com Temps | Gusts | WU KORD KPWK

CLICK for this month's BIG night sky ...

RADAR FULL MAP SCREEN

NEXRAD

STORMTRACK

Cardinal SAT

CHGOWX.COM



MOBILE DEVICE? Turn sideways. Weather conditions directly above are near Lakefront. Top tabs refer to O'Hare (official).

Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.

ARLINGTON HEIGHTS WEATHER

Wednesday, September 25, 2024

SPC Sep 25, 2024 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
1143 AM CDT Wed Sep 25 2024

Valid 251630Z - 261200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
GULF COAST INTO THE SOUTHERN/CENTRAL APPALACHIANS AND FLORIDA
PENINSULA...

...SUMMARY...
Isolated severe storms are possible this afternoon from parts of the
Southeast and central/southern Appalachians to the Texas/Louisiana
Gulf Coast. Some tornado threat may develop across the Florida
Peninsula by this evening, in association with Tropical Cyclone
Helene.

..Southeast and southern Appalachians...
The influence of the upstream mid/upper-level trough and moisture
streaming north from the Gulf of Mexico and Helene will lead to
widespread precipitation across parts of the Southeast and southern
Appalachians. This will tend to limit available buoyancy in some
areas, but strong to locally severe storms may occur. Favorable
deep-layer winds/shear exist, especially across the southern
Appalachians vicinity where a few semi-discrete supercells could
occur aside from more prevalent quasi-linear convective bands.
Locally damaging wind gusts and perhaps a tornado could accompany
the strongest storms, before low/mid-level lapse rates and buoyancy
become increasingly weak with time, and an outflow-reinforced
effective front sags southward across the region.

...Texas Gulf Coast/Middle Gulf Coast...
Somewhat stronger diurnal destabilization will be possible from
parts of central/east Texas into Louisiana, and perhaps into
Mississippi, with MLCAPE potentially increasing above 1500 J/kg.
Isolated to widely scattered thunderstorm development will be
possible near a southward-moving cold front. Effective shear will
generally range from 25-35 kt, and a few modestly organized storms
are possible. Isolated damaging gusts could accompany the strongest
storms within this regime.

...Florida Peninsula and Keys...
Hurricane Helene's wind field is forecast to be rather large,
especially on the east side of the circulation, associated with a
strengthening Helene through the afternoon and tonight. Reference
the National Hurricane Center for the latest Helene details. This
scenario will result in modestly strengthening low-level shear/SRH
across the Florida Peninsula during the day, but more so into the
evening and overnight after the peak diurnal instability cycle.
Instability will likely remain rather weak overall, and details
regarding the intensity of any outer rain bands remain uncertain.
However, some tropical-cyclone tornado threat could evolve across
parts of the Florida Peninsula and Keys, mainly into tonight.

...Eastern Washington/northern Idaho/northwest Montana...
While buoyancy is expected to remain quite weak, relatively steep
mid-level lapse rates will support thunderstorm potential late this
afternoon through early evening from eastern Washington into
northern Idaho and northwest Montana, in advance of the approaching
shortwave trough. Strong deep-layer flow/shear could support a
locally severe storm or two with gusty winds and possibly some hail.

..Guyer/Lyons.. 09/25/2024


Read more CHECK UPDATE ZOOM GRAPHIC


http://dlvr.it/TDgkx9
SUNRISE AND SUNSET TIMES IN UTC (if you're not logged in to Google)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)