SPC Sep 18, 2020 2000 UTC Day 1 Convective Outlook

SPC Sep 18, 2020 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0238 PM CDT Fri Sep 18 2020

Valid 182000Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE
NORTH-CENTRAL OR VICINITY...

...SUMMARY...
A couple thunderstorms capable of strong to marginally severe wind
gusts and small hail are possible across north-central Oregon
between about 1 to 7 PM PDT.

...20Z Update...

...OR vicinity...
Recent radar imagery shows a band of showers and thunderstorms
extending from about 40-45 miles northwest of Salem to 30 miles
southeast Eugene. This band is along the leading edge of a compact
vorticity maximum moving into the central/southern OR coast.
Instability will remain limited, but the strong forcing for ascent
and moderate deep-layer vertical shear could contribute to the
potential for a few stronger storms capable of damaging wind gusts.

..Mosier.. 09/18/2020

.PREV DISCUSSION... /ISSUED 1055 AM CDT Fri Sep 18 2020/

...OR vicinity...
A shortwave trough off the OR coast will slowly advance inland
across the Pacific Northwest. The belt of strong mid-level flow
attendant to this trough should become centered across central CA
and northwest NV later this afternoon. Scattered thunderstorms will
most likely be displaced farther north in the zone of ascent east of
the trough from western to north-central OR. A narrow corridor of
sufficient deep-layer shear for mid-level updraft rotation
overlapping with meager buoyancy may occur across north-central OR.
A supercell is possible in this region, most likely capable of
strong to marginally severe wind gusts and small hail.

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SPC Day 2 Fire Weather Outlook

SPC Day 2 Fire Weather Outlook

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook Image
Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0138 PM CDT Fri Sep 18 2020

Valid 191200Z - 201200Z

The main forecast change for this update was the addition of an
elevated risk area along the central High Plains. Recent reports
from local WFOs indicate that fuels are receptive across this
region, and morning guidance has come into better agreement
regarding the potential for reduced RH values into the 15-20% range
along the lee of the Rockies as well as 15-20 mph winds to the east
over the Plains. While there will likely be displacement of the
lowest RH values and the strongest winds, a region of overlap
appears probable, and given the receptive fuels, should support
elevated fire weather conditions.

..Moore.. 09/18/2020

.PREV DISCUSSION... /ISSUED 0204 AM CDT Fri Sep 18 2020/

...Synopsis...
The upper-level trough within the Northwest is expected to
accelerate northeastward on D2/Saturday. The mid-level jet will move
from the northern Great Basin into the central Rockies. A deep
surface cyclone will develop in the Canadian Prairie with an
attendant lee trough southward into the central High Plains. The
Pacific front will continue to progress south and east during the
day.

...Southern Great Basin into the central Rockies...
Moderate to strong mid-level flow will remain across portions of the
Great Basin into Wyoming. Deep boundary-layer mixing ahead of the
advancing boundary will combine with an increasing surface pressure
gradient to promote 15-20 mph winds. RH will likely fall to 10-20%.
Winds will be strongest in Wyoming beneath the mid-level jet.
However, faster eastward progression of the front as well as cloud
cover should limit the potential for and duration of critical
conditions.

...Central High Plains Vicinity...
With the deepening lee trough, enhanced southerly winds are probable
from the Colorado/Kansas border into the Nebraska Panhandle. With
surface trajectories emanating from a surface high pressure system
within the Great Lakes, there is some potential for RH to fall below
what guidance suggests. Winds in some areas may reach 15-20 mph and
promote locally elevated conditions where fine fuels remain
receptive to fire spread and RH falls to 20-25%.

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

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SPC Sep 18, 2020 1730 UTC Day 2 Convective Outlook

SPC Sep 18, 2020 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook
Day 2 Outlook Image
Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1211 PM CDT Fri Sep 18 2020

Valid 191200Z - 201200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe thunderstorms are not currently expected across the
contiguous United States on Saturday.

...Synopsis...
Upper pattern is expected to be relatively progressive on Saturday
as the trough/ridge/trough orientation shifts eastward. The western
upper trough is forecast to extend south-central BC into the western
Great Basin early Saturday before continuing eastward/northward
throughout the day, reaching the northern High Plains by the end of
the period. Cooler mid-level temperatures, increased mid-level
moisture, and persistent forcing for ascent associated with this
upper trough will contribute to isolated thunderstorms from the
northern/central Rockies into the northern High Plains. Majority of
this activity is expected to be displaced north of the stronger
mid-level flow, limiting vertical shear and likely precluding severe
thunderstorm development.

Upper troughing will spread across the Plains ahead of the western
trough while the eastern troughing gradually drifts eastward,
deepening late in the period as shortwave trough moves through its
base over the Upper Great Lakes. 

Surface pattern across much of the eastern CONUS will be dominated
by an expansive area of high pressure. Lee troughing is anticipated
across the northern and central High Plains ahead of the approaching
western CONUS trough, but limited low-level moisture should temper
any thunderstorm potential.

Isolated thunderstorms also appear possible across parts of the FL
Peninsula, ahead of a weakening frontal zone, and along portions of
the Gulf Coast, associated with deepening Tropical Depression 22.

..Mosier.. 09/18/2020

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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
1111 AM CDT Fri Sep 18 2020

Valid 181700Z - 191200Z

...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN NEVADA AND
WESTERN UTAH...
...CRITICAL FIRE WEATHER AREA FOR WESTERN NEVADA...

The ongoing forecast remains on track with only minor adjustments
made to account for recent trends in ensemble guidance as well as
ongoing precipitation across central NV. Recent VAD observations
from northern CA and western NV show increasing mid-level flow
associated with the approach of an upper-level wave. Meanwhile,
satellite imagery shows extensive cloud cover overspreading central
CA and NV, which introduces some uncertainty into how widespread
sustained conditions will be due to the potential for limited
diurnal heating. However, the observed strengthening of mid-level
winds noted above, along with relatively shallow (1500 ft or less)
nocturnal inversions under steep lapse rates (per 12 UTC soundings),
support the idea that sustained winds over 20 mph with higher gusts
remain likely.

...Dry Thunderstorms...
Although a thunderstorm or two is possible across northern to
northeastern NV and western ID today, recent MRMS estimates show
accumulating rainfall already ongoing over central to northeastern
NV. This suggests that thunderstorms that do develop in this region
will have attendant rainfall, and that fuel receptiveness may be
somewhat reduced by prior light precipitation.

..Moore.. 09/18/2020

.PREV DISCUSSION... /ISSUED 0102 AM CDT Fri Sep 18 2020/

...Synopsis...
A strong upper-level trough will continue to move inland from the
Pacific Northwest today. Mid-level flow will increase south and east
of this feature. A surface low will deepen within the northern
Rockies into southern Alberta/Saskatchewan which will bring an
associated Pacific front into the Northwest and northern Great Basin
by late afternoon.

...Nevada/Utah...
A combination of a strengthening surface gradient ahead of the front
and enhanced southwesterly flow aloft will promote elevated to
critical fire weather conditions in parts of southern Nevada and
adjacent western Utah. With these areas expected to see relatively
less cloud cover during the afternoon, confidence is higher in 20+
mph surface winds along with 5-15% RH. In western Nevada, in the lee
of the Sierra, strong downslope flow underneath the mid-level jet is
expected. Winds of 20-30 mph and 10-15% RH are possible, though
there is some continued uncertainty as to how long these conditions
will overlap. Some precipitation is possible ahead of the front in
north-central Nevada. Though lightning is possible with this
activity, very limited buoyancy keeps confidence in the need for dry
thunder highlights low.

...Southern Idaho/southern Wyoming...
Elevated fire weather conditions are possible in southern Idaho and
Wyoming. These conditions are expected to remain rather brief and
localized with the front/clouds moving in and weaker mid-level flow,
respectively. RH could still fall as low as 5-20% with 15-20 mph in
these locations.

...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

Severe Thunderstorm Warning

Severe Thunderstorm Warning

This is an automatic message WUUS52 KGSP 141812
SVRGSP
NCC175-SCC007-045-073-077-141845-
/O.NEW.KGSP.SV.W.0018.190414T1812Z-190414T1845Z/

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

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for…
Southern Transylvania County in western North Carolina…
Northwestern Greenville County in Upstate South Carolina…
North central Anderson County in Upstate South Carolina…
Pickens County in Upstate South Carolina…
Northeastern Oconee County in Upstate South Carolina…

* Until 245 PM EDT.

* At 211 PM EDT, a severe thunderstorm was located near Clemson,
moving northeast at 45 mph.

HAZARD…60 mph wind gusts and quarter size hail.

SOURCE…Radar indicated.

IMPACT…Minor hail damage to vehicles is expected. Expect wind
damage to trees and power lines.

* Locations impacted include…
Easley, Clemson, Pickens, Central, Liberty, Norris, Six Mile,
Rosman, Salem and Jocassee Gorges.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

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 700 PM EDT for Upstate South
Carolina.

LAT…LON 3460 8293 3507 8301 3527 8261 3526 8262
3526 8260 3517 8259 3515 8258 3475 8253
TIME…MOT…LOC 1811Z 223DEG 54KT 3468 8285

TORNADO…POSSIBLE
HAIL…1.00IN
WIND…60MPH

$$

Carroll