SPC Severe Thunderstorm Watch 238

WW 238 SEVERE TSTM NM OK TX 251800Z - 260100Z
      
WW 0238 Image
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 238
NWS Storm Prediction Center Norman OK
100 PM CDT Sat May 25 2019

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Eastern New Mexico
  Oklahoma Panhandle
  West Texas including the Panhandle

* Effective this Saturday afternoon and evening from 100 PM until
  800 PM CDT.

* Primary threats include...
  Widespread large hail and isolated very large hail events to 3
    inches in diameter likely
  Scattered damaging wind gusts to 70 mph likely
  A tornado or two possible

SUMMARY...Thunderstorms will continue to increase in coverage this
afternoon over parts of eastern New Mexico and west Texas, with
large hail expected in the strongest cells.  The risk of a tornado
or two will also increase later this afternoon.

The severe thunderstorm watch area is approximately along and 55
statute miles east and west of a line from 10 miles west northwest
of Elkhart KS to 70 miles southwest of Lubbock TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
3 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
24030.

...Hart

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SPC Severe Thunderstorm Watch 238 Status Reports

WW 0238 Status Updates
      
WW 0238 Status Image
STATUS FOR WATCH 0238 HAS NOT BEEN ISSUED YET
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SPC MD 787

MD 0787 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN NEW MEXICO AND WEST TEXAS
MD 0787 Image

Mesoscale Discussion 0787
NWS Storm Prediction Center Norman OK
1212 PM CDT Sat May 25 2019

Areas affected...Eastern New Mexico and west Texas

Concerning...Severe potential...Watch possible 

Valid 251712Z - 251915Z

Probability of Watch Issuance...60 percent

SUMMARY...Storms are developing along the dryline in eastern NM/west
TX with storm coverage increasing throughout the afternoon. Severe
hail/wind are the main threats.

DISCUSSION...Storms will continue to initiate along the dryline this
afternoon with a moist airmass in place (60-70 F surface dewpoints)
and strong insolation. Per water vapor imagery, a mid-level
shortwave trough is also likely contributing to storm initiation
along the dryline. Storms will be developing in a conducive severe
environment characterized by 2000-3000+ J/kg of MLCAPE and 40-45
knots of effective bulk shear. Large hail and damaging winds will be
the primary threats given the high/strong CAPE/shear, although the
tornado risk will increase this afternoon/evening as the LLJ
strengthens and storms move into an environment with better
low-level veering wind profiles.

..Nauslar/Hart.. 05/25/2019

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

ATTN...WFO...LUB...AMA...MAF...ABQ...

LAT...LON   32020288 32660227 33320195 34210193 35260197 36140210
            36470227 36570255 36150329 35160385 34020414 32860408
            32120381 32060358 32020288 

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SPC MD 786

MD 0786 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF IN INTO WESTERN OH
MD 0786 Image

Mesoscale Discussion 0786
NWS Storm Prediction Center Norman OK
1207 PM CDT Sat May 25 2019

Areas affected...portions of IN into western OH

Concerning...Severe potential...Watch possible 

Valid 251707Z - 251830Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorms will increase this afternoon across parts of
Indiana into Ohio. Damaging wind gusts will be the main concern, but
hail is also possible with the strongest cells.

DISCUSSION...Thunderstorms were increasing early this afternoon
across central IN ahead of an eastward advancing MCV. A very moist
airmass with dewpoints in the mid 60s to near 70 F and strong
heating with temperatures already in the low to mid 80s has resulted
in MLCAPE in the 500-1500 J/kg range. Some additional
destabilization is possible into the afternoon hours, but in the
absence of steeper midlevel lapse rates, instability will generally
be weak to moderate. Nevertheless, strong vertical shear will
support organized, intense convection. Damaging wind gusts will be
the main concern given the steep low level lapse rates, high PW
values and rather quick storm motion. Deep layer flow will remain
generally unidirectional, but speed shear could be adequate for some
supercell structures with an attendant hail risk, in addition to
bowing segments. A watch may be needed shortly for the MCD area.

..Leitman/Hart.. 05/25/2019

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

ATTN...WFO...PBZ...RLX...CLE...ILN...IWX...IND...LOT...

LAT...LON   40508713 40628677 41088483 41468315 41678115 41138079
            40278111 39548173 39098251 39078449 39188582 39288676
            39518733 39908737 40508713 

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SPC MD 785

MD 0785 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR WESTERN NY...WESTERN PA...FAR EASTERN OH...NORTHERN WV AND WESTERN MD
MD 0785 Image

Mesoscale Discussion 0785
NWS Storm Prediction Center Norman OK
1153 AM CDT Sat May 25 2019

Areas affected...western NY...western PA...far eastern OH...northern
WV and western MD

Concerning...Severe potential...Watch possible 

Valid 251653Z - 251900Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms will increase in coverage and intensity over
the next couple of hours. Strong to locally damaging wind gusts are
possible with the strongest storms, though hail is also possible. A
watch may be needed in the next few hours across this region.

DISCUSSION...Widely scattered thunderstorms were developing early
this afternoon on the nose of eastward surging boundary layer
moisture from northwest PA/eastern OH into WV. A warm front was
lifting northeast across NY/PA/VA just ahead of this convection.
Dewpoints in the mid 60s to near 70 F will spread eastward with time
today and convection should increase in coverage and intensity as
continued strong heating and destabilization occurs in strong deep
layer west/southwesterly flow. Forecast RAP soundings indicated
steepening low level lapse rates, with 30-40 kt southwest winds
around 760-700 mb at the top of the mixed boundary layer, suggesting
strong to locally damaging wind gusts will be possible. While
midlevel lapse rates are unimpressive, around 6.5-7 C/km at best,
vertical shear will support rotating updrafts and a few supercell
structures are possible. This will bring an attendant risk for
severe hail with the strongest storms. While forecast LCLs are
relatively high at around 3kft, any storm that interacts with the
warm front or through favorable cell/outflow interactions, could
produce a tornado or two given modestly favorable low level
hodographs and effective SRH around 150-200 m2/s2. Convective trends
will continue to be monitored and a watch may be needed in the next
few hours.

..Leitman/Hart.. 05/25/2019

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

ATTN...WFO...BUF...CTP...LWX...PBZ...RLX...CLE...

LAT...LON   42268012 43077936 43237887 43127821 42657783 41637782
            40377808 38997901 38537950 38408048 38818177 39208192
            39778157 40878088 41848039 42268012 

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SPC May 25, 2019 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
1128 AM CDT Sat May 25 2019

Valid 251630Z - 261200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE TEXAS AND OKLAHOMA PANHANDLES...WESTERN OKLAHOMA...AND SOUTHERN
KANSAS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE
UPPER OHIO VALLEY...

...SUMMARY...
Severe thunderstorms are likely this afternoon into tonight from the
Texas and Oklahoma Panhandles into western/northern Oklahoma and
Kansas. Other severe storms are expected across the upper Ohio River
Valley and Allegheny Plateau, and possibly other portions of the
Midwest.

...OH Valley...
Morning satellite imagery shows a well-defined shortwave trough
moving rapidly eastward across IL.  Strong heating is occurring
ahead of this feature across much of IN/OH.  Surface dewpoints in
the upper 60s and afternoon high temperatures well into the 80s will
yield a corridor of MLCAPE values around 1500 J/kg.  Present
indications are that thunderstorms will intensify this afternoon
across central IN and track into much of OH.  Meanwhile, more
isolated strong storms will form across parts of western NY/PA. 
Strong flow aloft and steep low-level lapse rates suggest a risk of
damaging wind gusts in the strongest cells across this region today.
 A few storms may also become supercells with a risk of hail or
perhaps a tornado.

...Southern/Central Plains...
Fast southwesterly flow aloft persists across west TX into adjacent
parts of OK/KS today, with only subtle large-scale forcing
mechanisms noted.  One such feature is apparent in water vapor
imagery near the Big Bend region.  This shortwave trough will affect
west TX by mid afternoon.  Ample low level moisture is in place
across this area with dewpoints in the mid 60s as far west as
eastern NM.  Current indications are that storms will initially form
near the diffuse dryline along the NM/TX border, with other activity
developing northeastward into parts of southwest KS through the
afternoon.  Forecast soundings indicate that supercell structures
will be the prominent mode - at least initially.  Very large hail
and damaging wind gusts are the main risks.  This evening, the risk
of tornadoes is expected to increase as the low level jet
strengthens somewhat over the eastern TX Panhandle and western OK.

Storms will spread east-northeastward across much of KS this
evening, and into parts of MO tonight.  These storms will maintain a
risk of hail and damaging wind gusts.

...Northern Great Basin...
A strong upper trough is present today over northern CA and western
NV, with  a shortwave trough rotating northeastward across NV. 
Rather fast flow aloft extends across much of the Great Basin, with
scattered afternoon thunderstorms expected.  Several 12z CAM
solutions indicate a risk of a few stronger updrafts tracking from
northern UT into parts of southeast ID and western WY.  Forecast
soundings suggest sufficient CAPE above inverted-v profiles -
favorable for gusty/damaging wind gusts.  CAM guidance also suggests
a few bowing structures are possible.

..Hart/Nauslar.. 05/25/2019

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SPC May 25, 2019 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
1220 PM CDT Sat May 25 2019

Valid 261200Z - 271200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE PLAINS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OH
VALLEY AND MIDDLE ATLANTIC...

...SUMMARY...
Severe thunderstorms are expected across the Plains Sunday while
isolated strong/severe storms should develop from the Ohio Valley
into the Middle Atlantic.

...Plains...

Strong mid-level speed max off the CA coast is forecast to dig into
the base of western US trough, over the northern Baja Peninsula, by
the start of the day2 period. This feature will then eject into the
High Plains by late afternoon where it should encourage a
substantial amount of convective overturning along the western
fringe of a very moist/buoyant air mass. Extensive thunderstorm
activity is expected across parts of the southern High Plains day1
but uninhibited inflow across far west TX should easily replenish
moisture into eastern NM/TX South Plains as LLJ strengthens
northward into the central High Plains region. Air mass recovery is
expected as far north as the northern High Plains where surface dew
points should rise through the 50s, and perhaps near 60F across
western SD by late afternoon. Strong heating in the immediate lee of
the higher terrain should allow parcels to reach their convective
temperatures ahead of the aforementioned short wave. As a result,
scattered supercells are expected to develop from the Trans Pecos
region of west TX, north across eastern NM/CO into eastern WY.
Substantial shear in conjunction with the ejecting short wave
suggest a long-lived convective event that should spread east across
KS/NE during the overnight hours. Very large hail, tornadoes, and
perhaps severe wind gusts can be expected.

...OH Valley/Middle Atlantic...

Southern Rockies mid-level speed max is forecast to eject across KS
later this evening before translating into the Mid-MS Valley by
sunrise Sunday. This feature is expected to aid large-scale forcing
for ascent downstream across the OH Valley by mid day such that
scattered convection should grow upscale and spread/develop toward
the Middle Atlantic by mid afternoon. Forecast shear profiles
suggest deep westerly flow regime will support supercell development
along with an attendant threat for hail/wind.

...MAXIMUM RISK BY HAZARD...
Tornado:  10%     - Enhanced
Wind:     30%     - Enhanced
Hail:     30% SIG - Enhanced

..Darrow.. 05/25/2019

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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
1154 AM CDT Sat May 25 2019

Valid 251700Z - 261200Z

...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL NEW MEXICO...

The eastern extent of the elevated area across eastern NM has been
trimmed slightly based on morning surface observations, the
potential for isolated to scattered thunderstorms this afternoon,
and less receptive fuels across this region due to spring greenup.
No changes have been made to the critical area in central NM. See
the previous discussion below for more information.

..Gleason.. 05/25/2019

.PREV DISCUSSION... /ISSUED 0145 AM CDT Sat May 25 2019/

...Synopsis...
A stationary mid-level shortwave trough will amplify across the
southwest CONUS, with stronger flow aloft overspreading the Four
Corners region into the High Plains during the day. At the surface,
lee troughing will prevail across the central High Plains, with a
dryline propagating eastward by mid-afternoon. Downslope flow
associated with boundary layer mixing, and isallobaric flow
associated with lee-troughing, will both contribute to very dry,
windy surface conditions supportive of wildfire spread potential.
Across the southeast U.S, a large scale upper-level ridge will
remain in place, that combined with surface high pressure, will
promote large scale subsidence, with negligible precipitation
accumulations, and warm/dry surface conditions. 

...New Mexico...
By mid-afternoon, widespread 15-20 mph sustained southwesterly
surface winds will be in place across much of New Mexico, coincident
with 10-15% RH, where an elevated delineation has been made. A
critical delineation has also been maintained in central New Mexico,
where confidence remains high that surface winds will exceed 20 mph
for several hours during the afternoon, atop fuels that will be at
least modestly supportive of fire spread. Otherwise, more quiescent
fire conditions may be expected during the evening hours as boundary
layer stabilization will result in calmer winds and increasing RH.

...Southern Georgia into far northern Florida, far southwest South
Carolina and far southeast Alabama...
Hot, dry conditions will prevail across the area during the
afternoon, where rainfall accumulations have been relatively absent
for several days. Fuels are beginning to become supportive of fire
spread, and with little precipitation accumulations expected in the
near future, this trend is expected to continue. The aforementioned
upper-level ridge and surface high will temper the threat for
surface winds exceeding 15 mph, which would otherwise support very
favorable conditions for wildfire spread. Nonetheless, the warm, dry
conditions, combined with 10-15 mph surface flow originating from
weak sea-breezes, may promote at least locally elevated conditions
to the region.

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

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