SPC MD 62

SPC MD 62

MD 0062 CONCERNING FREEZING RAIN FOR NORTHEASTERN IL...CENTRAL/NORTHERN IN...WESTERN OH
MD 0062 Image

Mesoscale Discussion 0062
NWS Storm Prediction Center Norman OK
1201 AM CST Sat Jan 18 2020

Areas affected...Northeastern IL...Central/Northern IN...Western OH

Concerning...Freezing rain 

Valid 180601Z - 181000Z

SUMMARY...Greatest freezing rain potential will extend from
northeastern Illinois into western Ohio. Freezing rain rates could
exceed 0.05"/hr.

DISCUSSION...Well-defined warm conveyor has evolved from
MO-IL/IN-Lower MI. Strong isentropic ascent ahead of a pronounced
short-wave trough will continue through the night and a broad
corridor of precipitation should gradually shift from west to east
across the Mid-MS/OH Valley region. Strong warm advection has
gradually raised surface temperatures above freezing across much of
MO into central IL and substantial boundary-layer warming is
expected to change freezing rain to rain by 12z across much of IN.
Forecast soundings support this with strong warming at 850mb as
50-60kt LLJ strengthens across the OH Valley. Freezing rain threat
should linger across northeast IN into western OH through 12z.

..Darrow.. 01/18/2020

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

ATTN...WFO...ILN...IWX...IND...LOT...ILX...

LAT...LON   41878783 41718654 41428588 40648359 39718382 39708629
            40408767 41878783 

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SPC Jan 18, 2020 0600 UTC Day 1 Convective Outlook

SPC Jan 18, 2020 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1148 PM CST Fri Jan 17 2020

Valid 181200Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible from south Texas into the
central Gulf Coast states today. The risk for severe weather is low.

...Synopsis...
A mid-level trough will progress eastward through the mid- and
upper-Mississippi Valley regions into the Great Lakes region today.
This feature is expected to lose amplitude with time. At the
surface, a strong cyclone will lift into the upper Midwest/Lower
Great Lakes during the afternoon and evening. An attendant cold
front will move southeastward, reaching into the northern/central
Gulf of Mexico by the end of the period. A warm-frontal boundary
will be positioned within southern Alabama/Mississippi into the
western Florida Panhandle.

With the strongest upper-level forcing for ascent remaining to the
north, only isolated thunderstorm development along/near the frontal
boundaries is expected. Boundary-layer dewpoints in the low- to
mid-60s F within the warm sector will support only modest buoyancy.
With the exception of areas near the warm front, deep-layer and
low-level shear will be relatively weak. A conditional threat for
marginal supercell structures during the afternoon/early evening may
develop in portions of the western Florida Panhandle that receive
greater surface heating. Should that occur, a brief tornado would be
possible with storms interacting with the warm front. However, given
the uncertainties regarding surface-based destabilization and narrow
window of potential, no severe probabilities will be added at this
time.

..Wendt.. 01/18/2020

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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
0139 PM CST Thu Dec 19 2019

Valid 201200Z - 211200Z

...NO CRITICAL AREAS...

Locally elevated fire-weather conditions are possible in a couple of
locations: 1) across portions of west Texas where northerly surface
flow will increase to 10-15 mph and RH values falling to around 20%
and 2) across coastal ranges of San Diego County, where an offshore
pressure gradient will foster areas of 20 mph winds with higher
gusts amidst 20% RH values.  The marginality of these conditions and
fuel states in each region preclude any elevated delineations at
this time, though these regions will be re-evaluated in later
outlooks.

..Cook.. 12/19/2019

.PREV DISCUSSION... /ISSUED 0122 AM CST Thu Dec 19 2019/

...Synopsis...
High pressure and mostly light winds will dominate most of the CONUS
on Friday. Some dry conditions will be present in portions of
Arizona and New Mexico, but northerly winds will be light and fuels
are not all that dry. Therefore, no fire weather areas are
warranted.

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

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SPC Dec 18, 2019 Day 4-8 Severe Weather Outlook

SPC Dec 18, 2019 Day 4-8 Severe Weather Outlook

Day 4-8 Outlook
Day 4-8 Outlook Image
Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0357 AM CST Wed Dec 18 2019

Valid 211200Z - 261200Z

...DISCUSSION...
...Day 4-5/Sat-Sun - FL and portions of the Southeast...

Medium range guidance is in somewhat better agreement compared to
this time yesterday with regards to the evolution of the southern
stream upper low/trough over the southern Plains on Saturday.
Differences still exist in timing and intensity of this feature, but
in general, the low is expected to track eastward across the Gulf
Coast states toward FL through the weekend. Strong shear will
develop ahead of the upper low from FL into parts of GA/SC. Strong
surface high pressure and east/northeasterly low level flow will
limit rich boundary layer moisture across the region initially.
However, a surface low is expected to develop near the northern Gulf
Coast and track eastward through the weekend, allowing moisture to
return northward while increasing low level shear. As a result, some
severe potential is possible this weekend. However, uncertainty in
the track and intensity of the surface low, as well as concerns over
the quality of thermodynamics, precludes inclusion of severe
probabilities at this time. 

The remainder of the period will see an amplified upper ridge shift
from the western U.S. to the eastern U.S. by early next week. The
upper ridge will remain across the eastern half of the U.S. through
the end of the period, while a large-scale trough develops over the
West. As the trough develops over the West, expect chances for
thunderstorms to increase across portions of AZ/NM into the Plains
around Days 7/8-Tue/Wed, however, severe potential appears low.

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SPC Dec 18, 2019 0830 UTC Day 3 Severe Thunderstorm Outlook

SPC Dec 18, 2019 0830 UTC Day 3 Severe Thunderstorm Outlook

SPC 0830Z Day 3 Outlook
Day 3 Outlook Image
Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0223 AM CST Wed Dec 18 2019

Valid 201200Z - 211200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not expected on Friday.

...Synopsis...

The upper trough over the mid-section of the country will become
increasingly bifurcated on Friday. The northern branch of the trough
will shift east from the northern Plains to the Great Lakes. Further
south, an upper low will only slowly shift east from NM to the
southern Plains, while becoming cutoff from northern stream flow.
Strong surface high pressure will continue to dominate across much
of the CONUS, keeping Gulf moisture offshore. A weak trough will
develop across the southern Plains in response to the upper low, and
a cold front will track east/southeast across the region, but with
scant moisture and little instability to work with, thunderstorms
are not expected. 

Elsewhere, a shortwave impulse will track eastward toward the
Pacific Northwest coast, bringing a weak cold front near the coast
Saturday morning. This will result in continued precipitation near
the coast, but modest lapse rates and poor instability will preclude
thunderstorm activity.

..Leitman.. 12/18/2019

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SPC Tornado Watch 700 Status Reports

SPC Tornado Watch 700 Status Reports

WW 0700 Status Updates
WW 0700 Status Image

STATUS REPORT ON WW 700

SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 ENE LCH
TO 40 ESE ESF TO 30 NNW MCB TO 75 NW PIB.

WW 700 WILL BE EXTENDED FOR PORTIONS OF THE ONGOING WATCH THROUGH AT
LEAST 02 UTC PER LOCAL NWS OFFICE COORDINATION.

..SMITH..12/16/19

ATTN...WFO...JAN...SHV...LCH...LIX...


STATUS REPORT FOR WT 700 

SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS 

LAC001-009-019-023-033-037-039-053-063-077-091-097-105-117-121-
125-170000-

LA 
.    LOUISIANA PARISHES INCLUDED ARE

ACADIA               AVOYELLES           CALCASIEU           
CAMERON              EAST BATON ROUGE    EAST FELICIANA      
EVANGELINE           JEFFERSON DAVIS     LIVINGSTON          
POINTE COUPEE        ST. HELENA          ST. LANDRY          
TANGIPAHOA           WASHINGTON          WEST BATON ROUGE    
WEST FELICIANA       


MSC005-007-029-037-049-051-077-085-089-113-121-127-147-157-163-
170000-

MS 
.    MISSISSIPPI COUNTIES INCLUDED ARE

AMITE                ATTALA              COPIAH              
FRANKLIN             HINDS               HOLMES              
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SPC Tornado Watch 700 Status Reports

SPC Tornado Watch 700

WW 700 TORNADO AR LA MS TX CW 161640Z - 170000Z
WW 0700 Image

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 700
NWS Storm Prediction Center Norman OK
1040 AM CST Mon Dec 16 2019

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Far southern Arkansas
  Louisiana
  Western and central Mississippi
  Far eastern Texas
  Coastal Waters

* Effective this Monday morning and evening from 1040 AM until
  600 PM CST.

* Primary threats include...
  Several tornadoes and a couple intense tornadoes likely
  Widespread damaging winds likely with isolated significant gusts
    to 75 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...Several supercells are expected to develop and progress
east-northeast across the Sabine and Lower Mississippi Valleys this
afternoon. Tornadoes and damaging winds are anticipated, with the
peak tornado risk across portions of northern and central Louisiana
into western Mississippi.

The tornado watch area is approximately along and 100 statute miles
east and west of a line from 25 miles west of Lafayette LA to 70
miles north northeast of Monroe LA. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU0).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 24040.

...Grams

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