2 years 3 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 PM CDT Mon May 15 2023
Valid 161200Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY AFTERNOON
AND EVENING ACROSS PARTS OF CENTRAL AND EASTERN KENTUCKY...EASTERN
TENNESSEE...SOUTHWESTERN INTO SOUTH CENTRAL VIRGINIA...WESTERN AND
CENTRAL NORTH CAROLINA....UPSTATE SOUTH CAROLINA AND ADJACENT
NORTHEASTERN GEORGIA...
...SUMMARY...
Clusters of thunderstorms may form and gradually consolidate across
parts of the Tennessee Valley and Cumberland Plateau through the
Appalachian Piedmont Tuesday afternoon and evening. Some of these
storms may initially be accompanied by a risk for severe hail,
before strong wind gusts become the more prominent potential severe
hazard.
...Synopsis...
A vigorous short wave impulse digging around the western through
southwestern periphery of a mid-level low, now digging into northern
Quebec, may contribute to elongation of the low and/or amplification
of larger-scale, positively tilted mid-level troughing across much
of the Northeast during this period. As this occurs, it appears
likely to be accompanied by a significant surface cold front, which
is forecast to surge south of the St. Lawrence Valley and upper
Great Lakes region, into the northern Mid Atlantic coast, upper Ohio
and Mississippi Valleys by 12Z Wednesday. A stalled, or slower
moving, and weaker preceding front, initially extending across the
Mid Atlantic coast into the lower Ohio Valley and southern Great
Plains, may advance southward into the Tennessee Valley and through
the southern Mid Atlantic coast, in response to the progression of a
weak frontal wave.
Upstream of the broadly confluent mid-level regime evolving east of
the Mississippi Valley, models indicate that mid-level ridging will
build across British Columbia, with an embedded high evolving, in
the wake of a significant short wave perturbation digging into the
Canadian Prairies. It appears that the latter feature will be
accompanied by lower/mid-tropospheric cyclogenesis, and another cold
front which may advance across the international border to the east
of the northern Rockies by 12Z Wednesday.
...Lower Ohio/Tennessee Valleys into Mid Atlantic...
Along and ahead of the initially stalled or slow moving surface
front, a seasonably moist boundary-layer across the lower Ohio and
Tennessee Valleys is forecast to destabilize with daytime heating,
while also advecting across the Appalachians, toward the Mid
Atlantic, during the day. Despite the presence of only modestly
cool mid-level temperatures, with generally weak lapse rates, this
moisture may become supportive of mixed-layer CAPE on the order of
1000-2000 J/kg (with larger CAPE remaining west of the Appalachians)
along the frontal zone.
Beneath a corridor of strengthening westerly flow in the 850-500 mb
layer (on the order of 30-50 kt), it appears that the environment
will become potentially supportive of organized convective
development. Initiation of storms may be aided by a couple of
perturbations progressing through the evolving and amplifying
larger-scale cyclonic mid-level flow, with convection tending to
grow upscale and perhaps gradually consolidate into one
east-southeastward propagating cluster and associated surface cold
pool, accompanied by potentially damaging wind gusts.
..Kerr.. 05/15/2023
Read more2 years 3 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 PM CDT Mon May 15 2023
Valid 161200Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY AFTERNOON
AND EVENING ACROSS PARTS OF CENTRAL AND EASTERN KENTUCKY...EASTERN
TENNESSEE...SOUTHWESTERN INTO SOUTH CENTRAL VIRGINIA...WESTERN AND
CENTRAL NORTH CAROLINA....UPSTATE SOUTH CAROLINA AND ADJACENT
NORTHEASTERN GEORGIA...
...SUMMARY...
Clusters of thunderstorms may form and gradually consolidate across
parts of the Tennessee Valley and Cumberland Plateau through the
Appalachian Piedmont Tuesday afternoon and evening. Some of these
storms may initially be accompanied by a risk for severe hail,
before strong wind gusts become the more prominent potential severe
hazard.
...Synopsis...
A vigorous short wave impulse digging around the western through
southwestern periphery of a mid-level low, now digging into northern
Quebec, may contribute to elongation of the low and/or amplification
of larger-scale, positively tilted mid-level troughing across much
of the Northeast during this period. As this occurs, it appears
likely to be accompanied by a significant surface cold front, which
is forecast to surge south of the St. Lawrence Valley and upper
Great Lakes region, into the northern Mid Atlantic coast, upper Ohio
and Mississippi Valleys by 12Z Wednesday. A stalled, or slower
moving, and weaker preceding front, initially extending across the
Mid Atlantic coast into the lower Ohio Valley and southern Great
Plains, may advance southward into the Tennessee Valley and through
the southern Mid Atlantic coast, in response to the progression of a
weak frontal wave.
Upstream of the broadly confluent mid-level regime evolving east of
the Mississippi Valley, models indicate that mid-level ridging will
build across British Columbia, with an embedded high evolving, in
the wake of a significant short wave perturbation digging into the
Canadian Prairies. It appears that the latter feature will be
accompanied by lower/mid-tropospheric cyclogenesis, and another cold
front which may advance across the international border to the east
of the northern Rockies by 12Z Wednesday.
...Lower Ohio/Tennessee Valleys into Mid Atlantic...
Along and ahead of the initially stalled or slow moving surface
front, a seasonably moist boundary-layer across the lower Ohio and
Tennessee Valleys is forecast to destabilize with daytime heating,
while also advecting across the Appalachians, toward the Mid
Atlantic, during the day. Despite the presence of only modestly
cool mid-level temperatures, with generally weak lapse rates, this
moisture may become supportive of mixed-layer CAPE on the order of
1000-2000 J/kg (with larger CAPE remaining west of the Appalachians)
along the frontal zone.
Beneath a corridor of strengthening westerly flow in the 850-500 mb
layer (on the order of 30-50 kt), it appears that the environment
will become potentially supportive of organized convective
development. Initiation of storms may be aided by a couple of
perturbations progressing through the evolving and amplifying
larger-scale cyclonic mid-level flow, with convection tending to
grow upscale and perhaps gradually consolidate into one
east-southeastward propagating cluster and associated surface cold
pool, accompanied by potentially damaging wind gusts.
..Kerr.. 05/15/2023
Read more2 years 3 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 PM CDT Mon May 15 2023
Valid 161200Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY AFTERNOON
AND EVENING ACROSS PARTS OF CENTRAL AND EASTERN KENTUCKY...EASTERN
TENNESSEE...SOUTHWESTERN INTO SOUTH CENTRAL VIRGINIA...WESTERN AND
CENTRAL NORTH CAROLINA....UPSTATE SOUTH CAROLINA AND ADJACENT
NORTHEASTERN GEORGIA...
...SUMMARY...
Clusters of thunderstorms may form and gradually consolidate across
parts of the Tennessee Valley and Cumberland Plateau through the
Appalachian Piedmont Tuesday afternoon and evening. Some of these
storms may initially be accompanied by a risk for severe hail,
before strong wind gusts become the more prominent potential severe
hazard.
...Synopsis...
A vigorous short wave impulse digging around the western through
southwestern periphery of a mid-level low, now digging into northern
Quebec, may contribute to elongation of the low and/or amplification
of larger-scale, positively tilted mid-level troughing across much
of the Northeast during this period. As this occurs, it appears
likely to be accompanied by a significant surface cold front, which
is forecast to surge south of the St. Lawrence Valley and upper
Great Lakes region, into the northern Mid Atlantic coast, upper Ohio
and Mississippi Valleys by 12Z Wednesday. A stalled, or slower
moving, and weaker preceding front, initially extending across the
Mid Atlantic coast into the lower Ohio Valley and southern Great
Plains, may advance southward into the Tennessee Valley and through
the southern Mid Atlantic coast, in response to the progression of a
weak frontal wave.
Upstream of the broadly confluent mid-level regime evolving east of
the Mississippi Valley, models indicate that mid-level ridging will
build across British Columbia, with an embedded high evolving, in
the wake of a significant short wave perturbation digging into the
Canadian Prairies. It appears that the latter feature will be
accompanied by lower/mid-tropospheric cyclogenesis, and another cold
front which may advance across the international border to the east
of the northern Rockies by 12Z Wednesday.
...Lower Ohio/Tennessee Valleys into Mid Atlantic...
Along and ahead of the initially stalled or slow moving surface
front, a seasonably moist boundary-layer across the lower Ohio and
Tennessee Valleys is forecast to destabilize with daytime heating,
while also advecting across the Appalachians, toward the Mid
Atlantic, during the day. Despite the presence of only modestly
cool mid-level temperatures, with generally weak lapse rates, this
moisture may become supportive of mixed-layer CAPE on the order of
1000-2000 J/kg (with larger CAPE remaining west of the Appalachians)
along the frontal zone.
Beneath a corridor of strengthening westerly flow in the 850-500 mb
layer (on the order of 30-50 kt), it appears that the environment
will become potentially supportive of organized convective
development. Initiation of storms may be aided by a couple of
perturbations progressing through the evolving and amplifying
larger-scale cyclonic mid-level flow, with convection tending to
grow upscale and perhaps gradually consolidate into one
east-southeastward propagating cluster and associated surface cold
pool, accompanied by potentially damaging wind gusts.
..Kerr.. 05/15/2023
Read more2 years 3 months ago
000
ABPZ20 KNHC 151714
TWOEP
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Mon May 15 2023
For the eastern North Pacific...east of 140 degrees west longitude:
Tropical cyclone formation is not expected during the next 7 days.
Today marks the first day of the eastern North Pacific hurricane
season, which will run until November 30. Long-term averages for
the number of named storms, hurricanes, and major hurricanes are
15, 8, and 4, respectively.
The list of names for 2023 is as follows:
Name Pronunciation Name Pronunciation
-------------------------------------------------------------
Adrian AY-dree-uhn Max maks
Beatriz BEE-a-triz Norma NOOR-muh
Calvin KAL-vin Otis OH-tis
Dora DOR-ruh Pilar Pee-LAHR
Eugene YOU-jeen Ramon rah-MOHN
Fernanda fer-NAN-dah Selma SELL-mah
Greg greg Todd tahd
Hilary HIH-luh-ree Veronica vur-RAHN-ih-kuh
Irwin UR-win Wiley WY-lee
Jova HO-vah Xina ZEE-nah
Kenneth KEH-neth York york
Lidia LIH-dyah Zelda ZEL-dah
This product, the Tropical Weather Outlook, briefly describes
significant areas of disturbed weather and their potential for
tropical cyclone formation during the next seven days. The issuance
times of this product are 5 AM, 11 AM, 5 PM, and 11 PM PDT. After
the change to standard time in November, the issuance times are
4 AM, 10 AM, 4 PM, and 10 PM PST.
A Special Tropical Weather Outlook will be issued to provide
updates, as necessary, in between the regularly scheduled issuances
of the Tropical Weather Outlook. Special Tropical Weather Outlooks
will be issued under the same WMO and AWIPS headers as the regular
Tropical Weather Outlooks.
A standard package of products, consisting of the tropical cyclone
public advisory, the forecast/advisory, the cyclone discussion, and
a wind speed probability product, is issued every six hours for all
ongoing tropical cyclones. In addition, a special advisory package
may be issued at any time to advise of significant unexpected
changes or to modify watches or warnings.
NHC has the option to issue advisories, watches, and warnings for
disturbances that are not yet a tropical cyclone, but which pose
the threat of bringing tropical storm or hurricane conditions to
land areas within 48 hours. For these land-threatening "potential
tropical cyclones", NHC will issue the full suite of advisory and
watch/warning products. Potential tropical cyclones share the
naming conventions currently in place for tropical depressions,
being numbered from a single list (e.g., "One-E", "Two-E",
"Three-E", etc.).
The Tropical Cyclone Update is a brief statement to inform of
significant changes in a tropical cyclone, to post or cancel
watches or warnings, or to provide hourly position updates between
intermediate advisories when the storm center is easily followed by
radar. The Tropical Cyclone Update is also used in lieu of or to
precede the issuance of a special advisory package. Tropical
Cyclone Updates, which can be issued at any time, can be found
under WMO header WTPZ61-65 KNHC, and under AWIPS header MIATCUEP1-5.
All NHC text and graphical products are available on the web at
https://www.hurricanes.gov. More information on NHC text products
can be found at https://www.hurricanes.gov/aboutnhcprod.shtml,
while more information about NHC graphical products can be
found at https://www.hurricanes.gov/aboutnhcgraphics.shtml.
You can also interact with NHC on Facebook at
https://www.facebook.com/NWSNHC. Notifications are available
via Twitter when select NHC products are issued. Information
about our east Pacific Twitter feed is available at
https://www.hurricanes.gov/twitter.php.
$$
Forecaster Kelly/Cangialosi
NHC Webmaster
2 years 3 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0258 PM CDT Sun May 14 2023
Valid 142000Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID
MISSISSIPPI VALLEY...
...SUMMARY...
Thunderstorms capable of producing damaging wind gusts and hail are
possible later this afternoon into this evening across parts of the
mid Mississippi Valley.
...20Z Update...
The Marginal Risk area has been trimmed from the south and expanded
slightly eastward, based on the progression of an arc of convection
associated with a compact cyclone moving across east TX. Otherwise,
no changes have been made to the severe probabilities. Scattered
strong to potentially severe thunderstorms remain possible across
parts of the mid MS Valley into this evening, with a threat of
locally damaging wind gusts and isolated hail. A more isolated
severe threat remains evident across northeast TX, and from eastern
KS into western MO. See MCD 792, MCD 793, MCD 794, and the previous
outlook discussion below for more information.
..Dean.. 05/14/2023
.PREV DISCUSSION... /ISSUED 1130 AM CDT Sun May 14 2023/
...Mid-Mississippi Valley including Missouri/Illinois...
Thunderstorms are expected to develop/increase this afternoon
initially across northern/eastern Missouri near a weak surface low
and a southeastward-extending front, with additional/more isolated
warm sector development across eastern Kansas and central/southern
Missouri. Over time, storms should build southeastward along the
low-level theta-e/CAPE axis into southern Illinois. Winds aloft are
only modestly strong. Nevertheless, the combination of a moist and
moderately unstable airmass and linear forcing mechanisms along the
front may be sufficient for a few bowing structures posing a risk of
locally damaging winds and hail.
...East Texas...
Within a moist environment, a belt of moderately strong
low/mid-level southerly winds will tend to persist and shift
north-northeastward today on the eastern periphery of a weak low.
Weak mid-level lapse rates along with cloud cover and existing
precipitation will tend to limit overall destabilization, but a few
stronger storms capable of water-loaded downbursts could materialize
this afternoon across eastern Texas.
Read more2 years 3 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0215 PM CDT Sun May 14 2023
Valid 151200Z - 161200Z
...NO CRITICAL AREAS...
The previous forecast (see below) remains on track, with no changes
or additions made.
..Squitieri.. 05/14/2023
.PREV DISCUSSION... /ISSUED 0155 AM CDT Sun May 14 2023/
...Synopsis...
In the wake of a departing midlevel trough, a belt of strong
deep-layer west-northwesterly flow will extend from northern Canada
east-southeastward into the northeastern United States. Along the
southern periphery of this enhanced flow, a dry air mass will be in
place from the Upper MS Valley eastward into the Great Lakes and
Northeast. Boundary-layer heating/mixing through this corridor could
yield 20-30 percent RH, which combined with breezy/gusty westerly
surface winds, could support locally elevated fire-weather
conditions over parts of the Upper MS Valley and Northeast (where
fuels are modestly dry). However, the wildfire threat appears too
localized for Elevated highlights at this time.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more2 years 3 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 PM CDT Sun May 14 2023
Valid 151200Z - 161200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE OZARKS
AND VICINITY...
...SUMMARY...
Isolated severe storms appear possible on Monday afternoon and
evening across the Ozark region and vicinity. Locally damaging winds
and isolated hail are expected to be the primary hazards.
...Ozarks and vicinity...
A convectively enhanced midlevel shortwave trough is forecast to
move from eastern OK into parts of the Ozarks on Monday, around the
periphery of a weakening upper ridge over the Southeast. Meanwhile,
an outflow-reinforced surface boundary is expected to become draped
somewhere across southern MO/northern AR during the afternoon, with
a weak surface low potentially developing along the front in
response to the approaching shortwave. Rich low-level moisture and
diurnal heating will support MLCAPE increasing into the 1000-2000
J/kg range (locally higher) by late afternoon with minimal capping.
Scattered thunderstorm development is expected Monday afternoon in
the vicinity of the front as the shortwave approaches the region.
With modest deep-layer flow/shear in place, multicell clusters
appear to be the most likely mode, though a marginal supercell
cannot be ruled out where shear may be locally enhanced near the
boundary. Locally damaging outflow/downburst gusts may be the most
likely hazard, though isolated hail cannot be ruled out, despite
generally weak midlevel lapse rates.
...Northwest...
Scattered thunderstorms are expected Monday afternoon and evening
across much of the Northwest, in association with a weakening
mid/upper-level low that is forecast to become nearly stationary
near the Pacific Northwest coast. With generally modest instability
and deep-layer shear across the region, the organized
severe-thunderstorm threat appears limited at this time, though
small hail and gusty winds will be possible with the strongest
storms.
..Dean.. 05/14/2023
Read more2 years 3 months ago
MD 0789 CONCERNING TORNADO WATCH 223... FOR CENTRAL TO SOUTHEAST IOWA
Mesoscale Discussion 0789
NWS Storm Prediction Center Norman OK
0331 PM CDT Sat May 13 2023
Areas affected...Central to southeast Iowa
Concerning...Tornado Watch 223...
Valid 132031Z - 132230Z
The severe weather threat for Tornado Watch 223 continues.
SUMMARY...The tornado threat continues across parts of WW 223.
Confidence in the severe threat is highest across parts of
central/northwest IA as well as south-central/southeast IA for the
next few hours.
DISCUSSION...Regional radar imagery over the past couple of hours
has shown a broken band of discrete convection across northwest IA
as well as more discrete convection across central/southeast IA.
Despite a favorable thermodynamic and kinematic environment for
supercells (MLCAPE over 1000 J/kg and 40-50 knots of effective bulk
shear per latest RAP analyses), convection thus far appears to not
be fully realizing the available environment based on the relatively
short lifespan of individual cells and rather anemic appearance of
most convection in IR imagery. This is likely due to fairly weak
low-level forcing for ascent with a notable diminishment of cumulus
depth and westward retrograde of the warm front noted in surface obs
across central IA. Despite this limitation, a few brief tornadoes
have been reported since 18 UTC, and the KDMX VWP continues to
sample 0-1 km SHR on the order of 100-150 m2/s2. Given the
aforementioned environmental characteristics, a conditional tornado
threat continues across the entire watch area.
Over the next couple of hours, a relatively higher severe threat
will likely be focused within two corridors to the northwest and
southeast of the Des Moines area. Within these corridors, visible
satellite imagery has shown persistent agitated cumulus and multiple
attempts at more robust convection. This supports recent RAP
analyses that depict locally enhanced low-level convergence and
ambient vorticity along the frontal boundary that may be conducive
for tornadogenesis with any stronger updraft. Recent hi-res guidance
continues to hint that the greatest potential for long-lived
tornadic supercells resides across south-central IA, which matches
environmental trends (higher buoyancy and stronger baroclinicity
along the warm front) and recent radar/satellite observations.
..Moore.. 05/13/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DVN...DMX...EAX...FSD...
LAT...LON 41489446 41689472 42009506 42309534 42639551 42809541
42899506 42779454 42389404 41949339 41739279 41559216
41369180 41089158 40679172 40589204 40599254 40769304
40979355 41079378 41489446
Read more2 years 3 months ago
MD 0789 CONCERNING TORNADO WATCH 223... FOR CENTRAL TO SOUTHEAST IOWA
Mesoscale Discussion 0789
NWS Storm Prediction Center Norman OK
0331 PM CDT Sat May 13 2023
Areas affected...Central to southeast Iowa
Concerning...Tornado Watch 223...
Valid 132031Z - 132230Z
The severe weather threat for Tornado Watch 223 continues.
SUMMARY...The tornado threat continues across parts of WW 223.
Confidence in the severe threat is highest across parts of
central/northwest IA as well as south-central/southeast IA for the
next few hours.
DISCUSSION...Regional radar imagery over the past couple of hours
has shown a broken band of discrete convection across northwest IA
as well as more discrete convection across central/southeast IA.
Despite a favorable thermodynamic and kinematic environment for
supercells (MLCAPE over 1000 J/kg and 40-50 knots of effective bulk
shear per latest RAP analyses), convection thus far appears to not
be fully realizing the available environment based on the relatively
short lifespan of individual cells and rather anemic appearance of
most convection in IR imagery. This is likely due to fairly weak
low-level forcing for ascent with a notable diminishment of cumulus
depth and westward retrograde of the warm front noted in surface obs
across central IA. Despite this limitation, a few brief tornadoes
have been reported since 18 UTC, and the KDMX VWP continues to
sample 0-1 km SHR on the order of 100-150 m2/s2. Given the
aforementioned environmental characteristics, a conditional tornado
threat continues across the entire watch area.
Over the next couple of hours, a relatively higher severe threat
will likely be focused within two corridors to the northwest and
southeast of the Des Moines area. Within these corridors, visible
satellite imagery has shown persistent agitated cumulus and multiple
attempts at more robust convection. This supports recent RAP
analyses that depict locally enhanced low-level convergence and
ambient vorticity along the frontal boundary that may be conducive
for tornadogenesis with any stronger updraft. Recent hi-res guidance
continues to hint that the greatest potential for long-lived
tornadic supercells resides across south-central IA, which matches
environmental trends (higher buoyancy and stronger baroclinicity
along the warm front) and recent radar/satellite observations.
..Moore.. 05/13/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DVN...DMX...EAX...FSD...
LAT...LON 41489446 41689472 42009506 42309534 42639551 42809541
42899506 42779454 42389404 41949339 41739279 41559216
41369180 41089158 40679172 40589204 40599254 40769304
40979355 41079378 41489446
Read more
