RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Jan 28 10:56:01 UTC 2020.
No Mesoscale Discussions are in effect as of Tue Jan 28 10:56:01 UTC 2020.
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0112 AM CST Tue Jan 28 2020
Valid 301200Z - 311200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe storms are not expected across the U.S. mainland Thursday.
...Southwest through central Texas...
A shortwave trough now approaching the Pacific Northwest coast will
move southeast, reaching the northern Mexico and southwest TX area
early Thursday before continuing east through TX during the day. A
preceding Gulf frontal intrusion will limit moisture return through
TX. However, steep lapse rates and ascent attending the shortwave
trough will result in at least weak MUCAPE (100-300 J/kg) with the
base of the convective layer near 700 mb. A few showers and
thunderstorms may spread from southwest through central TX during
the day and into the evening. However, coverage will likely remain
sparse due to limited moisture return and instability.
..Dial.. 01/28/2020
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0251 AM CST Tue Jan 28 2020
Valid 311200Z - 051200Z
...DISCUSSION...
Friday (Day 4) Model consensus is that a southern-stream shortwave
trough will deamplify as it phases with a northern-stream trough and
continues east northeast through the Southeastern States. A warm
front will move north into southern FL accompanied by weak
instability, but the front will remain south of the corridor of
stronger vertical shear accompanying the deamplifying shortwave
trough. While some risk for severe storms could evolve from this
potential scenario as storms develop in vicinity of the warm front,
current indications are that instability will probably remain too
marginal for a more substantial threat.
Saturday-Sunday (days 5-6) The boundary across FL will transition to
a cold front as cyclogenesis commences off the Atlantic seaboard in
association with the progressive southern-stream shortwave trough.
The front will move off the FL Peninsula during the day, and while a
few thunderstorms may develop along this boundary, instability is
expected to remain too weak for a substantial severe threat. Later
Saturday through Sunday the Gulf frontal intrusion will result in
stable conditions inland.
By days 7-8 (Monday-Tuesday) richer Gulf moisture will begin
returning through east TX and the lower MS Valley ahead of the next
shortwave trough. While a severe threat might evolve from east TX
into the Southeast States during this period, too much uncertainty
exists regarding timing and amplitude of these waves to introduce a
categorical severe risk area at this time.
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0104 AM CST Tue Jan 28 2020
Valid 281200Z - 291200Z
...NO CRITICAL AREAS...
...Synopsis...
A pair of mid-level shortwave troughs and associated surface lows
will traverse the south-central and southwest CONUS, respectively,
throughout the period. Elsewhere, surface high pressure is expected
to dominate much of the rest of the CONUS, with cooler temperatures
prevailing.
As the south-central surface low continues to track eastwards, a
cold front will continue to progress across southern/eastern Texas.
25+ mph sustained north-northwesterly surface winds will accompany
the post-cold frontal environment across far western/southwestern
TX. While 20% RH values will be found near the Texas/Mexico border
by afternoon, most areas across the Texas side of the border will
experience RH above 20%, that in tandem with marginally receptive
fuels, will preclude an elevated delineation.
Elsewhere, across the southeast, 30-40% RH will prevail by afternoon
peak heating across southern Georgia into the eastern Florida
Panhandle and northern Florida Peninsula. The lack of a stronger
surface wind field, along with marginally receptive fine fuels, also
precludes an elevated delineation for parts of the southeast, though
localized fire starts will remain possible during the afternoon.
..Squitieri.. 01/28/2020
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0105 AM CST Tue Jan 28 2020
Valid 291200Z - 301200Z
...NO CRITICAL AREAS...
...Synopsis...
A mid-level trough will amplify across the Inter-mountain West, as a
downstream mid-level shortwave ejects into the Atlantic Day
2/Wednesday. A deepening surface low across northwest Mexico will
encourage a broad region of relatively strong northerly surface flow
across portions of southern California into the Southern Colorado
River Basin during the afternoon. Otherwise, relatively cool
conditions are expected across most of the lower 48.
Southerly flow will be prevalent ahead of the aforementioned low
across West Texas, with boundary layer mixing encouraging RH to drop
to 20% by afternoon peak heating. The strength of the low-level flow
and marginally receptive fuels suggests that the wildfire-spread
threat appears low enough to withhold an elevated delineation.
20-30 mph sustained northerly surface flow and 20% RH will occur
across southern California into the Lower Colorado River Basin
during the afternoon. Locally stronger gusts and lower RH values are
possible in terrain favoring areas, especially with the offshore
component of flow across portions of the southern Transverse Ranges
in southern California. At the moment, the biggest negative factor
for adding an elevated area continues to be the marginally receptive
fuels, though localized fire spread may occur wherever patchy, more
receptive fine fuels coincide with the stronger winds/lower RH.
..Squitieri.. 01/28/2020
...Please see www.spc.noaa.gov/fire for graphic product...
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