SPC MD 201

MD 0201 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NORTHEASTERN KS…FAR SOUTHEASTERN NE…NORTHERN MO…AND SOUTHERN/CENTRAL IA

MD 0201 Image


Mesoscale Discussion 0201
NWS Storm Prediction Center Norman OK
0948 PM CST Thu Feb 23 2017

Areas affected...Northeastern KS...far southeastern NE...northern
MO...and southern/central IA

Concerning...Severe potential...Watch unlikely 

Valid 240348Z - 240615Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated marginally severe hail may occur with elevated
thunderstorms through the early overnight hours. Watch issuance is
unlikely.

DISCUSSION...A band of elevated convection located over far
southeastern NE as of 0330Z is associated with forcing for ascent
attendant to a shortwave trough over the central Plains and a
strengthening low-level jet over MO/IA. These thunderstorms will
very likely remain elevated to the north of a frontal boundary as a
surface low across southeastern KS translates northeastward across
MO toward western IL overnight. Although near-surface moisture will
be meager, sufficient low-level moisture centered around 850 mb per
the 00Z Topeka, KS sounding combined with steep mid-level lapse
rates in excess of 8 degrees C/km will generally support MUCAPE of
250-1000 J/kg, decreasing with northward extent into central IA.
Effective shear on the order of 40-60 kt will support updraft
organization, and isolated instances of marginally severe hail may
occur through the early overnight hours if thunderstorms can remain
relatively discrete. With time, clustering of thunderstorms cores
will likely occur as they move northeastward into an increasingly
marginal thermodynamic environment in central/northern IA.

..Gleason/Hart.. 02/24/2017

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

ATTN...WFO...LSX...DVN...DMX...EAX...OAX...TOP...

LAT...LON   39189605 39419667 40809630 41399589 42459369 42639224
            42439137 41659092 40839089 39619344 39129518 39189605 

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SPC MD 181

MD 0181 CONCERNING TORNADO WATCH 33… FOR PORTIONS OF WESTERN/SOUTHERN LA AND FAR EAST TX

MD 0181 Image


Mesoscale Discussion 0181
NWS Storm Prediction Center Norman OK
1115 AM CST Tue Feb 14 2017

Areas affected...Portions of western/southern LA and far east TX

Concerning...Tornado Watch 33...

Valid 141715Z - 141845Z

The severe weather threat for Tornado Watch 33 continues.

SUMMARY...The risk for damaging wind gusts and perhaps a couple of
tornadoes continues across Watch 33, though the severe potential
presently appears to be becoming increasingly isolated/conditional.

DISCUSSION...The latest mosaic radar imagery indicates a broken
squall line advancing eastward across portions of the lower Sabine
Valley vicinity, and this activity will continue to spread eastward
during the next few hours. Cloud tops accompanying the broader
convective system have been warming based on infrared satellite
imagery, implying an overall weakening convective trend.
Furthermore, surface pressure tendencies ahead of this activity are
small in magnitude. This is likely a reflection of the deeper ascent
accompanying a deamplifying midlevel cyclonic perturbation lagging
well to the northwest of richer Gulf moisture serving as inflow to
the convective system.

Nevertheless, the latest visible satellite imagery and surface
observations suggest that a more substantially modified Gulf air
mass continues advancing inland ahead of the aforementioned
activity. This air mass is preceded by a marine boundary extending
around 30-60 miles north of the southern LA coast. Diurnal surface
heating east of the ongoing convection -- especially where
mid/high-level cloud canopies are thinning -- may support sufficient
destabilization amidst this moisture for a conditional severe risk
persisting into the afternoon.

The LCH VAD wind profile indicates around 45-50 kt of 0-6-km bulk
shear with sufficient low-level directional shear for around 200
m2/s2 of 0-1-km SRH. As such, damaging winds and perhaps some
tornado potential could conditionally accompany deeper convective
elements embedded within the squall line -- especially if more
vigorous updrafts were to become separated within the line.

..Cohen.. 02/14/2017

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

ATTN...WFO...LCH...SHV...

LAT...LON   29549223 29869397 30849412 31429386 31589350 31429295
            30429235 29549223 

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SPC MD 175

MD 0175 CONCERNING HEAVY SNOW FOR MAINE

MD 0175 Image


Mesoscale Discussion 0175
NWS Storm Prediction Center Norman OK
0610 AM CST Mon Feb 13 2017

Areas affected...Maine

Concerning...Heavy snow 

Valid 131210Z - 131815Z

SUMMARY...Heavy snowfall will continue across much of south-central
to eastern Maine this morning with snowfall rates of 1 to 2 inches
per hour possible within the most concentrated bands. Blizzard
conditions will also be possible near the coast of Maine from
Augusta to Eastport and inland to about 80 statute miles.

DISCUSSION...An upper-level low will move quickly offshore from near
Cape Cod today as a surface low rapidly deepens about 180 statute
miles to the southeast of the eastern tip of Maine. This surface low
will bomb out to about 972 mb by midday as a Nor'easter continues
across northern New England including the eastern half of Maine. As
this occurs, deep-layer vertical motion to the north of the
upper-level low will become very strong maintaining and even
increasing snowfall rates over the next 2 to 4 hours. This
enhancement of large-scale ascent is already becoming evident on IR
imagery with rapid and expansive cloud top cooling evident over
southern Maine. The heaviest snowfall is expected to occur along a
corridor from near Augusta northeastward through the Bangor vicinity
to the Canadian border to the north of Eastport where snowfall rates
could reach 2 inches per hour within the heaviest bands. Blizzard
conditions will also be possible along this corridor where
tightening surface pressure gradients will create wind speeds from
25 to 35 mph with gusts to 45 mph.

..Broyles.. 02/13/2017

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

ATTN...WFO...CAR...GYX...

LAT...LON   46396821 46176747 45426703 45016692 44556733 43706961
            43867052 44687085 45586992 46396821 

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SPC MD 175

MD 0175 CONCERNING HEAVY SNOW FOR MAINE

MD 0175 Image


Mesoscale Discussion 0175
NWS Storm Prediction Center Norman OK
0610 AM CST Mon Feb 13 2017

Areas affected...Maine

Concerning...Heavy snow 

Valid 131210Z - 131815Z

SUMMARY...Heavy snowfall will continue across much of south-central
to eastern Maine this morning with snowfall rates of 1 to 2 inches
per hour possible within the most concentrated bands. Blizzard
conditions will also be possible near the coast of Maine from
Augusta to Eastport and inland to about 80 statute miles.

DISCUSSION...An upper-level low will move quickly offshore from near
Cape Cod today as a surface low rapidly deepens about 180 statute
miles to the southeast of the eastern tip of Maine. This surface low
will bomb out to about 972 mb by midday as a Nor'easter continues
across northern New England including the eastern half of Maine. As
this occurs, deep-layer vertical motion to the north of the
upper-level low will become very strong maintaining and even
increasing snowfall rates over the next 2 to 4 hours. This
enhancement of large-scale ascent is already becoming evident on IR
imagery with rapid and expansive cloud top cooling evident over
southern Maine. The heaviest snowfall is expected to occur along a
corridor from near Augusta northeastward through the Bangor vicinity
to the Canadian border to the north of Eastport where snowfall rates
could reach 2 inches per hour within the heaviest bands. Blizzard
conditions will also be possible along this corridor where
tightening surface pressure gradients will create wind speeds from
25 to 35 mph with gusts to 45 mph.

..Broyles.. 02/13/2017

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

ATTN...WFO...CAR...GYX...

LAT...LON   46396821 46176747 45426703 45016692 44556733 43706961
            43867052 44687085 45586992 46396821 

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SPC MD 85

MD 0085 CONCERNING TORNADO WATCH 10… FOR SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI

MD 0085 Image


Mesoscale Discussion 0085
NWS Storm Prediction Center Norman OK
0255 AM CST Sat Jan 21 2017

Areas affected...Southeast Louisiana and southern Mississippi

Concerning...Tornado Watch 10...

Valid 210855Z - 211100Z

The severe weather threat for Tornado Watch 10 continues.

SUMMARY...Severe weather including a tornado threat will persist
across southeast Louisiana and southern Mississippi during the
overnight.  The greatest threat for tornadoes in the short term is
expected to be from the vicinity of BTR and eastward from Hammond,
LA to Hattiesburg, MS with the increase in supercell development.

DISCUSSION...Recent surface analyses /06-08Z/ indicated a developing
mesolow, now located near BTR, with the strongest pressure falls
from BTR to MCB, while this region and into southwest and
south-central MS also has the coldest cloud tops and greatest
lightning coverage/density.  The mesolow is expected to track to the
east-northeast along a northward-developing warm front through
southern MS to central AL (near or just south of a TCL-BHM line) per
trends in mesoanalyses and HRRR forecasts.  Forcing for ascent
associated with a progressive and compact shortwave trough moving
into Louisiana at this time will sustain a low-level mass response
across and downstream from WW 10.  This response is being observed
per backed southerly low-level winds with an associated increase in
low-level moistening and warm air advection.  These factors will
further aid in the development of additional thunderstorms east of
the main BTR-MCB storm complex into southeast MS and southwest AL
through the overnight.  

Further strengthening of vertically veering wind profiles and
increasing deep-layer ascent per an apparent coupled jet structure
with the progressive trough suggest supercells should increase in
coverage and intensity across WW 10.

..Peters.. 01/21/2017

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

ATTN...WFO...BMX...MOB...JAN...LIX...LCH...

LAT...LON   29449124 30539175 31379168 31879103 32518987 32928915
            32928835 31048845 29848835 29078862 28828910 28718955
            28858997 28779109 29179122 29449124 

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SPC Center Public Severe Weather Outlook (PWO)

Public Severe Weather Outlook

PWO Image

PUBLIC SEVERE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0937 PM CST FRI JAN 20 2017

...Severe thunderstorms expected over parts of the  overnight...

* LOCATIONS...
  Southern Louisiana
  Southern Mississippi
  Southwestern Alabama

* HAZARDS...
  A few intense tornadoes
  Scattered damaging winds
  Isolated large hail up to baseball size

* SUMMARY...
  Scattered severe storms are expected to continue developing this
  evening across southwestern Louisiana, and spread across the
  lower Mississippi Valley and into Alabama and the Florida
  Panhandle tonight through Saturday morning. A few tornadoes,
  some of which could be strong, large hail and damaging winds
  will all be possible.

Preparedness actions...

Tornadoes at night can be particularly dangerous because they 
are usually fast-moving and difficult to see. Stay tuned to
NOAA Weather Radio, weather.gov, or other media for watches and
warnings. A tornado watch means that conditions are favorable
for tornadoes to form during the next several hours. If a tornado
warning is issued for your area, move to a place of safety,
ideally in a basement or interior room on the lowest floor of a
sturdy building.

&&

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from SPC Convective Outlooks http://bit.ly/1Mw5lDA

Dense Fog Advisory issued January 20 at 11:48PM CST until January 21 at 10:00AM CST by NWS

NOAA-NWS-ALERTS-KS125838E68A50.DenseFogAdvisory.125838E82540KS.TOPNPWTOP.f629d35aa0ad8646bb59674a52043b6d w-nws.webmaster@noaa.gov 2017-01-20T23:48:00-06:00 Actual Alert Public Alert for Brown; Clay; Cloud; Douglas; Jackson; Jefferson; Marshall; Nemaha; Pottawatomie; Republic; Riley; Shawnee; Wabaunsee; Washington (Kansas) Issued by the National Weather Service Met Dense Fog Advisory Expected Minor Likely SAME 2017-01-20T23:48:00-06:00 2017-01-21T10:00:00-06:00 NWS Topeka (Northeastern Kansas) Dense Fog Advisory issued January 20 at 11:48PM CST until January 21 at 10:00AM CST by NWS Topeka …DENSE FOG ADVISORY IN EFFECT UNTIL 10 AM CST SATURDAY… THE NATIONAL WEATHER SERVICE IN TOPEKA HAS ISSUED A DENSE FOG ADVISORY…WHICH IS IN EFFECT UNTIL 10 AM CST SATURDAY. * VISIBILITY…AREAS OF DENSE FOG WILL REDUCE VISIBILITIES BELOW A QUARTER MILE. * IMPACTS…REDUCED VISIBILITIES FROM DENSE FOG WILL CREATE HAZARDOUS DRIVING CONDITIONS. A DENSE FOG ADVISORY MEANS VISIBILITIES WILL FREQUENTLY BE REDUCED TO LESS THAN ONE QUARTER MILE. IF DRIVING…SLOW DOWN… USE YOUR HEADLIGHTS…AND LEAVE PLENTY OF DISTANCE AHEAD OF YOU. WMOHEADER UGC KSZ008>012-020>024-026-038>040 VTEC /O.NEW.KTOP.FG.Y.0003.170121T0548Z-170121T1600Z/ TIME…MOT…LOC
Brown; Clay; Cloud; Douglas; Jackson; Jefferson; Marshall; Nemaha; Pottawatomie; Republic; Riley; Shawnee; Wabaunsee; Washington FIPS6 020013 FIPS6 020027 FIPS6 020029 FIPS6 020045 FIPS6 020085 FIPS6 020087 FIPS6 020117 FIPS6 020131 FIPS6 020149 FIPS6 020157 FIPS6 020161 FIPS6 020177 FIPS6 020197 FIPS6 020201 UGC KSZ008 UGC KSZ009 UGC KSZ010 UGC KSZ011 UGC KSZ012 UGC KSZ020 UGC KSZ021 UGC KSZ022 UGC KSZ023 UGC KSZ024 UGC KSZ026 UGC KSZ038 UGC KSZ039 UGC KSZ040