SPC Apr 17, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 PM CDT Thu Apr 16 2026

Valid 170100Z - 171200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING
ACROSS PARTS OF EASTERN NEW YORK INTO WESTERN NEW ENGLAND...PARTS OF
THE OZARK PLATEAU INTO MID SOUTH...AND THE PECOS VALLEY/RIO GRANDE
VALLEY VICINITY...

...SUMMARY...
Widely scattered areas of scattered strong to severe thunderstorm
development are expected to generally wane through mid to late
evening.

...01Z Update...

...Parts of Upstate New York into western New England...
Forcing for ascent accompanying a weak frontal wave is maintaining
an area of scattered stronger storms now overspreading areas to the
northwest of Albany NY, in the presence of strong deep-layer shear.
Instability sampled in the evening sounding from Albany is rather
weak, but profiles might still be supportive of at least some risk
for localized severe wind and hail into mid/late evening as forcing
overspreads parts of southern Vermont, New Hampshire and adjacent
Maine.

...Ozark Plateau into Mid South...
The primary east-southeastward propagating organized storm cluster
appears to be in the process of weakening, as southeasterly near
surface updraft inflow across middle Tennessee becomes less
unstable. However, renewed thunderstorm development persists along
and to the cool side of the trailing convective outflow across the
Missouri Bootheel vicinity, with additional attempts along a diffuse
zone of differential surface heating extending westward across
northern Arkansas. This is occurring beneath warming and more
strongly capping lower/mid-tropospheric air, but given inflow of
potentially sizable CAPE, in the presence of moderate westerly
shear, there remains at least some risk for supercell development
capable of producing large hail this evening.

...West Texas...
Potential for sustained severe thunderstorm development appears low
along the retreating dryline across parts of northwest Texas into
the South Plains overnight.

..Kerr.. 04/17/2026


Read more CHECK UPDATE ZOOM GRAPHIC


http://dlvr.it/TS4gPw

SPC Apr 16, 2026 2000 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Thu Apr 16 2026

Valid 162000Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NEW YORK
INTO SOUTHERN VERMONT...AND THE OZARKS INTO THE MID-SOUTH...

...SUMMARY...
Scattered severe thunderstorms are possible this afternoon over New
York into southern Vermont with damaging gusts and perhaps a tornado
or two the primary threats. Very large hail and severe gusts are
possible with the stronger storms over the Ozarks into the
Mid-South.

...20Z Update...
The SLGT in the Ozarks/Mid-South was expanded northward into central
MO, where an isolated supercell with a risk of very large hail and
damaging gusts has emerged along the northern periphery of a remnant
cold pool. Farther south within Severe Thunderstorm Watch 127,
several discrete/splitting supercells continue to pose a risk of
very large hail (recent report of 2.75 inches) and locally damaging
wind gusts. With time, this activity may congeal into a loosely
organized cluster, with an increasing risk of damaging wind gusts.
The MRGL risk was also expanded slightly westward into southwest OK,
where boundary-layer cumulus is gradually deepening. Any isolated
storms that can form here will pose a risk of large to very large
hail and severe downbursts. Finally, the MRGL was expanded slightly
westward in southwest TX toward Fort Stockton. While convective
initiation is still in question here, deepening boundary-layer
cumulus along the higher terrain could result in an isolated storm
or two, with a risk of very large hail.

..Weinman.. 04/16/2026

.PREV DISCUSSION... /ISSUED 1124 AM CDT Thu Apr 16 2026/

...Ozark Plateau into the Mid-South...
Recent visible satellite imagery shows some ACCAS across
south-central MO, indicative of low/mid-level warm advection amid
the steep lapse rate environment in place. These steep lapse rates
are forecast to continue spread eastward, while low-level moisture
advection brings low 60s dewpoints northeastward into the region as
well. This will result in a moderate to strongly buoyant airmass
(i.e. MLCAPE from 1500 to 2000 J/kg) by the early afternoon.
Additionally, moderate mid to high level flow will remain in place,
resulting in long hodographs and overall environmental conditions
that are very favorable for supercells capable of large to very
large hail. Latest guidance continues the earlier trends of
developing storms in this area, which match observational
expectations as well. Large to very large hail (1 to 3 inches in
diameter) is possible with any updrafts that mature into supercells.
Low-level flow is weak, keeping tornado probability low but none
zero. Given the modest pocket of mid-level dry air present,
supercells will likely become outflow dominant with time,
supporting the potential for damaging gusts across the region
(particular eastern areas) as well.

...NY/VT/NH southeastward into the central Appalachians...
Recent surface analysis places a low over the eastern
Ontario/southern Quebec border vicinity, with modest surface
troughing extending southeastward from this low across central Lower
MI. Airmass across much of NY is characterized by dewpoints in the
low 60s. Dewpoints should stay in the low 60s throughout the day
despite modest mixing amid diurnal heating. This should result in
airmass destabilization ahead of the modest surface trough, with a
general increase in large-scale ascent beginning during the
afternoon as well. Little to no convective inhibition is
anticipated, supporting the potential for more cellular development
over the warm sector initially, before a more expansive convective
line develops along the eastward-progressing surface trough. Ample
mid to high-level flow will favor storm organization, including a
risk for large hail and a tornado with the more intense discrete
cells. The wind risk will tend to focus with linear structures that
evolve over time. An isolated threat for wind damage and perhaps
hail will extend southward into PA/WV and the Cumberland Plateau,
where a few stronger storms may yield those hazards.

...Edwards Plateau into the TX Big Country and western north TX...
A strongly buoyant and weakly capped airmass is expected to develop
along the dryline extending southwestward from western OK through
the Edwards Plateau. Although neutral to weak shortwave ridging is
expected throughout much of the morning into the late afternoon,
some limited ascent (associated with a weak shortwave trough moving
out of northern Mexico) may begin to spread across the dryline by
early evening. This combined with dryline circulations may be enough
to initiate isolated to widely scattered thunderstorms. Low-level
flow will be weak, but moderate to strong westerly flow aloft will
result in wind profiles very favorable for supercells capable of
large to very large hail. Any storms that develop should weaken
quickly with the onset of nocturnal cooling.


Read more CHECK UPDATE ZOOM GRAPHIC


http://dlvr.it/TS4WxV

SPC Apr 16, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0734 AM CDT Thu Apr 16 2026

Valid 161300Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NEW YORK INTO
SOUTHERN VERMONT AND OVER THE NORTHERN HALF OF ARKANSAS...

...SUMMARY...
Scattered severe thunderstorms are possible this afternoon over New
York into southern Vermont with damaging gusts and perhaps a tornado
or two the primary threats. Large to very large hail is possible
with stronger storms over the northern half of Arkansas.

...Northeast southward into the central Appalachians and Cumberland
Plateau...
Water-vapor imagery this morning shows an upper trough over the
mid/upper MS Valley moving east towards the Northeast. A belt of
strong west-southwesterly 500-mb flow (50-65 kt) will overspread
much of the Northeast today in conjunction with the
eastward-migrating shortwave trough. Visible-satellite imagery
shows scattered to broken cloud cover to the south of a west-east
oriented frontal zone extending east from a surface low analyzed
over Lake Huron. Heating of an adequately moist boundary layer
(surface dewpoints in the 56-62 deg F range) will result in weak to
locally moderate buoyancy by midday into the mid afternoon (500-1250
J/kg MLCAPE). Large-scale ascent associated with the approaching
disturbance and convergence in the vicinity of the frontal zone will
lead to scattered storm development this afternoon. Ample mid to
high-level flow will favor storm organization, including the
possibility for a few supercells and an organized band of storms. A
risk for large hail and a tornado could accompany the more intense
cells, whereas the wind risk will tend to focus with linear
structures that evolve. An isolated threat for wind damage and
perhaps hail will extend southward into PA/WV and the Cumberland
Plateau, where a few stronger storms may yield those hazards.

...Mid South...
Satellite imagery shows the trailing portion of the upper shortwave
trough over the western Great Lakes is moving east across OK this
morning. This upper feature and associated mid-level cold pocket
(-16 to -18 deg C at 500 mb) will move across the MO Ozarks and AR
this afternoon. A reservoir of lower 60s deg F surface dewpoints
and strong heating in wake of early day showers and isolated
thunderstorms will favor robust CAPE profiles and elongated mid to
upper portions of the hodograph. Latest guidance shows several
cells developing within a weakly capped airmass by mid afternoon.
The stronger storms will likely become supercells yielding a risk
for large to very large hail (1 to 3 inches in diameter). Modest
low-level flow will tend to limit low-level mesocyclone intensity
and the lessen the overall tornado risk. A couple of smaller
clusters may evolve during the early evening with an isolated wind
threat potentially ensuing before this activity weakens by mid
evening.

...Edwards Plateau into the TX Big Country and western north TX...
Moderate to strong potential instability is forecast to develop
beneath steep lapse rates, along and east of a dryline. Although
neutral to weak shortwave ridging is expected today, some of the
latest model guidance shows isolated to widely scattered storm
development by late afternoon on the northwestern rim of richer
low-level moisture arcing from the Edwards Plateau into western
north TX. Strong heating will likely erode appreciable remaining
convective inhibition by 20-22 UTC. Strong west-southwesterly
100-kt 200-mb flow will elongate hodographs amidst a moderately
buoyant airmass. Widely spaced/isolated supercells will mainly
yield a large hail threat late this afternoon into the early
evening.

..Smith/Dean.. 04/16/2026


Read more CHECK UPDATE ZOOM GRAPHIC


http://dlvr.it/TS4G4h

SPC Apr 16, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0109 AM CDT Thu Apr 16 2026

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
ACROSS PARTS OF WESTERN AND CENTRAL NEW YORK INTO SOUTHERN
VERMONT...

CORRECTED FOR TYPOS AND WORDING

...SUMMARY...
A few severe thunderstorms are possible this afternoon in a corridor
across western through central New York (state) and adjacent
southern Vermont.

...Discussion...
A significant mid-level trough and embedded low now digging across
the Pacific Northwest is forecast to split as it continues inland
through this period. One perturbation, perhaps including a
continuing cyclonic circulation, is forecast to turn eastward across
the northern Rockies through the central Canadian/U.S. border area.
Another perturbation is forecast to dig southeastward across the
Great Basin into early Friday. It appears that the larger-scale
evolving troughing will be preceded by a significant cold frontal
surge to the lee of the northern U.S. Rockies, through much of the
northern and central Great Plains by 12Z Friday.

Downstream, initially prominent mid-level ridging centered near the
southern Atlantic Seaboard is forecast to become increasingly
suppressed, as one short wave trough, approaching southwestern
portions of the Great Lakes region early today, turns eastward then
southeastward across the lower Great Lakes vicinity into northern
Mid Atlantic. It appears that this will be trailed by another
perturbation, which is forecast to progress east of the Ozark
Plateau through the lower Ohio and Tennessee Valleys, before digging
across the southern Appalachians, downstream of short wave ridging
building across and east of the mid/upper Mississippi Valley.

...Mid South into lower Great Lakes and Northeast...
The primary and trailing short wave troughs advancing to the east of
the Mississippi Valley are forecast to be preceded by the remnants
of overnight convection across parts of the lower Great Lakes, Ohio
Valley, and Mid South at the outset of the period. The impacts of
associated cloud cover and outflow on destabilization within the
warm sector of a broad, but weak, surface low migrating northeast of
the lower Great Lakes during the day remain unclear. However,
various model output, including convection allowing guidance,
suggest that destabilization and strengthening shear along a warm
frontal zone (as it strengthens with differential heating) may
become a focus for organized strong thunderstorm development across
New York state by afternoon. It appears that this may include an
evolving cluster, perhaps preceded by more discrete thunderstorm
activity, in an environment conducive to evolving supercell
structures, with potential to produce severe hail, wind and a risk
for a couple of tornadoes.

Additional thunderstorm activity may eventually develop and
strengthen, accompanied by at least a risk for strong to severe wind
gusts by late afternoon, in a corridor of stronger daytime heating
ahead of a developing cold front spreading into the upper Ohio
Valley/Allegheny and Cumberland Plateau.

Farther west/southwest, there is not a well-defined signal in the
latest model output, but a corridor of differential surface heating
along weakening trailing convective outflow across the Mid South
vicinity could become a focus for supercell development. It
currently appears that this potential could peak across north
central into northeastern Arkansas by late this afternoon, aided by
moderate boundary-layer destabilization and stronger mid-level
forcing for ascent associated with a cyclonic vorticity center
migrating across the region.

...Southern Great Plains...
Moderate to strong potential instability is forecast to develop
beneath steep lapse rates, along and east of a dryline which likely
will be retreating westward across the high plains by early this
evening. While this will be conditionally supportive of severe
thunderstorm development, forcing to support initiation of sustained
thunderstorms remains unclear, aside from, perhaps, the higher
terrain near/east of the Texas Big Bend. Beneath moderate to strong
southwesterly mid/upper flow, this could include an isolated
supercell or two which could propagate across the Rio Grande River,
before weakening in the presence of increasing inhibition this
evening.

..Kerr/Lyons.. 04/16/2026


Read more CHECK UPDATE ZOOM GRAPHIC


http://dlvr.it/TS3qml