SPC Sep 23, 2021 1630 UTC Day 1 Convective Outlook

SPC Sep 23, 2021 1630 UTC Day 1 Convective Outlook

SPC 1630Z Day 1 Outlook
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1125 AM CDT Thu Sep 23 2021

Valid 231630Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC INTO SOUTHERN NEW ENGLAND...

...SUMMARY...
Isolated strong to severe storms associated with a marginal threat
for a brief tornado and occasional wind damage should continue today
into tonight across parts of the Mid-Atlantic and southern New
England.

...Mid-Atlantic into Southern New England...
A band of showers and storms is ongoing across parts of the
Mid-Atlantic along and just ahead of a surface cold front. A zone of
large-scale ascent associated with low-level warm advection and
modest convergence along the front will continue through tonight,
while making slow eastward progress as a closed upper low moves
gradually northward across the Great Lakes region into southeastern
Ontario. Low-topped convection should continue to train northward
this afternoon and evening within the larger belt of precipitation
across the Mid-Atlantic.

The environment ahead of this activity should remain marginally
favorable for isolated strong to severe storms. Visible satellite
imagery shows a fair amount of cloud cover ahead of the line, which
should slow diurnal heating and steepening of low-level lapse rates
though the afternoon. Still, a moist low-level airmass characterized
by mid 60s to low 70s surface dewpoints combined with modest
diabatic heating should support generally 500-1250 J/kg of MLCAPE,
with greater instability across DE/NJ compared to southern NY and
vicinity.

The strongest and largely meridional winds are expected to remain
behind the surface cold front, with only about 30-35 kt of
deep-layer shear present across the warm sector. Even so, some
enhancement to the low-level wind field is present ahead of the band
of storms, and a brief embedded circulation capable of producing a
tornado or two remains possible. Otherwise, occasional strong to
damaging winds should be the main threat through the rest of the day
as the band of convection develops slowly eastward towards the
Atlantic Coast. This marginal severe threat may continue through
tonight across parts of southern New England where sufficient
boundary-layer moisture can support weak instability and the
potential surface-based storms.

..Gleason/Bentley.. 09/23/2021

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SPC Day 1 Fire Weather Outlook

SPC Day 1 Fire Weather Outlook

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook Image
Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1113 AM CDT Thu Sep 23 2021

Valid 231700Z - 241200Z

Only minor modifications were made to the outlook in the central
High Plains based on observational and model trends. See the
previous discussion for more details.

..Wendt.. 09/23/2021

.PREV DISCUSSION... /ISSUED 1232 AM CDT Thu Sep 23 2021/

...Synopsis...
Early morning surface observations show a cold front along the
US/Canada border. This feature will begin to shift southward through
the day as the parent surface low shifts eastward into the Canadian
Prairies in tandem with a passing upper-level trough. The passage of
this dry cold front, along with weak surface pressure falls
along/ahead of the boundary, will support increasing winds and
heightened fire weather concerns across parts of the Plains. Further
west where fuels are somewhat drier, weak surface flow will limit
most fire weather threats, though localized concerns may evolve in
northern California.

...Southern Plains...
Modest zonal flow across the central Rockies will yield some lee
troughing across the central High Plains ahead of the approaching
cold front. Weak surface pressure falls are already noted in morning
observations and support this general idea. The resulting mass
response will yield increasing southerly winds from northwest TX
into KS. An unseasonably dry air mass in place across TX and OK
(where dewpoint values are near the 10th percentile for this time of
year) and offshore flow along the Gulf Coast will support little
moisture return and RH values in the teens and low 20s this
afternoon. With ERC values continuing to climb close to the 90th
percentile, elevated conditions appear likely.

...Central High Plains...
Winds are forecast to increase to 15-20 mph in the wake of the cold
frontal passage this afternoon. While temperatures will see some
moderation, dry air advection from the north and a slight downslope
component will support RH reductions into the teens and low 20s.
While wind gusts up to 20-30 mph are possible during peak heating,
the potential for sustained 20+ mph winds appears low. Recent fuel
reports from the field suggest that fuels are generally receptive
and should support a elevated fire weather conditions.

...Northern California...
Building surface high pressure over the Pacific Northwest will
induce northerly downslope winds through the northern Sacramento
Valley. Winds may reach up to 15 mph by late afternoon, and RH
values in the teens are expected. While elevated conditions are
possible, the spatial extent and duration of this threat appears too
limited for highlights.

...Please see www.spc.noaa.gov/fire for graphic product...

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Severe Thunderstorm Warning

Severe Thunderstorm Warning

This is an automatic message WUUS52 KGSP 150312
SVRGSP
NCC045-071-109-SCC021-091-150400-
/O.NEW.KGSP.SV.W.0024.190415T0312Z-190415T0400Z/

BULLETIN – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
1112 PM EDT Sun Apr 14 2019

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for…
Eastern Lincoln County in the Piedmont of North Carolina…
Southeastern Cleveland County in the Piedmont of North Carolina…
Gaston County in the Piedmont of North Carolina…
Northwestern York County in Upstate South Carolina…
Northeastern Cherokee County in Upstate South Carolina…

* Until midnight EDT.

* At 1112 PM EDT, severe thunderstorms were located along a line
extending from near Shelby to 19 miles west of Gastonia to 6 miles
east of Gaffney, moving east at 35 mph.

HAZARD…60 mph wind gusts.

SOURCE…Radar indicated.

IMPACT…Expect damage to trees and power lines.

* Locations impacted include…
Gastonia, Shelby, Kings Mountain, Mt Holly, Belmont, Cherryville,
Bessemer City, South Gastonia, Clover and Dallas.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

These storms are also producing extremely heavy rainfall. Flooding of
drainage ditches and low lying areas may occur. Small streams will
rise rapidly. Do not drive through areas where water is flowing over
the road.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

A Tornado Watch remains in effect until 500 AM EDT for the Piedmont
of North Carolina…and Upstate South Carolina.

LAT…LON 3535 8097 3530 8100 3527 8102 3517 8100
3515 8101 3514 8105 3510 8103 3509 8106
3495 8165 3515 8157 3530 8163 3555 8106
3555 8096 3550 8096 3549 8095 3545 8094
3543 8096 3539 8095 3537 8099 3536 8092
TIME…MOT…LOC 0312Z 248DEG 32KT 3526 8153 3518 8150 3504 8155

TORNADO…POSSIBLE
HAIL…<.75IN WIND...60MPH $$ HG

Severe Thunderstorm Warning

Severe Thunderstorm Warning

This is an automatic message WUUS52 KGSP 150215
SVRGSP
SCC045-059-083-150300-
/O.NEW.KGSP.SV.W.0022.190415T0215Z-190415T0300Z/

BULLETIN – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
1015 PM EDT Sun Apr 14 2019

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for…
Northwestern Laurens County in Upstate South Carolina…
East central Greenville County in Upstate South Carolina…
Central Spartanburg County in Upstate South Carolina…

* Until 1100 PM EDT.

* At 1015 PM EDT, a severe thunderstorm was located 14 miles
southeast of Greenville Downtown, or 4 miles southeast of Five
Forks, moving east at 40 mph.

HAZARD…60 mph wind gusts.

SOURCE…Radar indicated.

IMPACT…Expect damage to trees and power lines.

* Locations impacted include…
Spartanburg, Simpsonville, Five Forks, Fountain Inn, Woodruff,
Pacolet, Cowpens, Roebuck, Pacolet Mills and Reidville.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

This storm is also producing extremely heavy rainfall. Flooding of
drainage ditches and low lying areas may occur. Small streams will
rise rapidly. Do not drive through areas where water is flowing over
the road.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

A Tornado Watch remains in effect until 500 AM EDT for Upstate South
Carolina.

LAT…LON 3463 8224 3482 8228 3503 8180 3499 8177
3493 8176 3493 8174 3491 8172 3483 8179
3461 8185
TIME…MOT…LOC 0215Z 250DEG 35KT 3476 8216

TORNADO…POSSIBLE
HAIL…<.75IN WIND...60MPH $$ HG

Severe Thunderstorm Warning

Tornado Warning

This is an automatic message WFUS52 KGSP 150116
TORGSP
SCC007-150145-
/O.NEW.KGSP.TO.W.0010.190415T0116Z-190415T0145Z/

BULLETIN – EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Greenville-Spartanburg SC
916 PM EDT Sun Apr 14 2019

The National Weather Service in Greenville-Spartanburg has issued a

* Tornado Warning for…
Central Anderson County in Upstate South Carolina…

* Until 945 PM EDT.

* At 916 PM EDT, a severe thunderstorm capable of producing a tornado
was located 10 miles southwest of Anderson, or near Lake Hartwell,
moving northeast at 35 mph.

HAZARD…Tornado.

SOURCE…Radar indicated rotation.

IMPACT…Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.

* This dangerous storm will be near…
Anderson, Northlake, Anderson Airport and Homeland Park around 930
PM EDT.
Belton around 940 PM EDT.

Other locations impacted by this dangerous thunderstorm include Sandy
Springs, Sadlers Creek State Park and Broadway Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT…LON 3437 8284 3444 8286 3447 8287 3449 8291
3448 8292 3449 8293 3475 8252 3467 8246
3462 8245 3459 8242 3456 8242 3454 8239
3451 8237 3435 8281
TIME…MOT…LOC 0116Z 238DEG 31KT 3446 8281

TORNADO…RADAR INDICATED
HAIL…<.75IN $$ HG

Severe Thunderstorm Warning

Tornado Warning

This is an automatic message WFUS52 KGSP 150041
TORGSP
NCC089-175-SCC045-077-150115-
/O.NEW.KGSP.TO.W.0009.190415T0041Z-190415T0115Z/

BULLETIN – EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Greenville-Spartanburg SC
841 PM EDT Sun Apr 14 2019

The National Weather Service in Greenville-Spartanburg has issued a

* Tornado Warning for…
Southeastern Transylvania County in western North Carolina…
South central Henderson County in western North Carolina…
Northwestern Greenville County in Upstate South Carolina…
Northwestern Pickens County in Upstate South Carolina…

* Until 915 PM EDT.

* At 841 PM EDT, a severe thunderstorm capable of producing a tornado
was located 11 miles northwest of Pickens, or 5 miles northeast of
Jocassee Gorges, moving northeast at 40 mph.

HAZARD…Tornado.

SOURCE…Radar indicated rotation.

IMPACT…Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.

* This dangerous storm will be near…
Table Rock State Park around 850 PM EDT.
Caesars Head State Park and Dupont State Forest around 900 PM EDT.
Jones Gap State Park and Pleasant Ridge State Park around 910 PM
EDT.

Other locations impacted by this dangerous thunderstorm include
Sunset, Pumpkintown, Little River In Transylvania County, Connestee
and Crab Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT…LON 3532 8258 3509 8239 3489 8283 3501 8293
3501 8291 3502 8292 3503 8292 3505 8290
3504 8296
TIME…MOT…LOC 0041Z 237DEG 35KT 3502 8281

TORNADO…RADAR INDICATED
HAIL…<.75IN $$ HG