| |
LU9DCE > ALERT 26.11.19 07:08z 154 Lines 8880 Bytes #999 (0) @ WW
BID : 3449_LU9DCE
Read: GUEST
Subj: Storm Prediction Center 26 11
Path: HB9ON<IW0QNL<OK0NBR<OK2PEN<N3HYM<N7HPX<LU9DCE
Sent: 191126/0701Z 3449@LU9DCE.TOR.BA.ARG.SOAM LinBPQ6.0.19
__ _ _ ___ ____ ___ ____ ____ ____ ____
( ) / )( \/ _ \( \ / __)( __) ( _ \( _ \/ ___)
/ (_/\) \/ (\__ )) D (( (__ ) _) ) _ ( ) _ (\___ \
\____/\____/(___/(____/ \___)(____) (____/(____/(____/
ESTACION DE PACKET RADIO - BUENOS AIRES (GF05OM)
BOLETINES INFORMATIVOS PROGRAMADOS (BIP)
SLACKWARE LINUX - HELLOCODELINUX@GMAIL.COM
+----------------------------------------------------------------------------+
MD 2153 CONCERNING HEAVY SNOW FOR PORTIONS OF THE FRONT RANGE AND
I-25 CORRIDOR
Mesoscale Discussion 2153 NWS Storm Prediction Center Norman OK
0842 PM CST Mon Nov 25 2019
Areas affected...Portions of the Front Range and I-25 corridor
Concerning...Heavy snow
Valid 260242Z - 260845Z
SUMMARY...Snowfall rates will increase tonight along the Front Range
and I-25 corridor. Snowfall rates of 1-2 inches per hour are likely
with 3+ inches per hour possible under the heaviest bands.
DISCUSSION...Snow has been falling within a region of frontogenesis
and upslope flow across the Front Range and adjacent I-25 corridor
since 20-21z with snowfall reports of 3-5+ inches per NWS BOU/CYS.
An upper-level shortwave trough is amplifying over the Intermountain
West with the upper low now located over northern Utah with
substantial IR cloud-top cooling ahead of it. As this wave further
amplifies and shifts eastward, lapse rates will steepen with stronger
forcing for ascent and intensifying isentropic lift and frontogenesis
over the Front Range and adjacent High Plains. This will result
in heavy snow with snowfall rates of 1-2 inches per hour between
03-10z with locally higher snowfall rates of 3+ inches per hour.
..Nauslar/Grams.. 11/26/2019
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BOU...CYS...
LAT...LON 40290561 40810566 41300569 41490524 41480448 41320398
40810403 40030413 39680422 39320460 39330543 39510562 40290561
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156
PM CST Mon Nov 25 2019
Valid 261200Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE LOWER/MID MS VALLEY...
...SUMMARY... Isolated to scattered severe storms with a threat
for damaging winds and a few tornadoes will be possible across parts
of the lower to mid Mississippi Valley this afternoon and tonight.
...Synopsis... A powerful mid-latitude cyclone will strengthen
further today as it acquires a negative tilt and ejects northeastward
from the southern/central Rockies across the Plains, eventually
reaching the Upper Midwest and Great Lakes region by the end of the
period. A very strong mid/upper-level jet (100+ kt at 500 mb and
175+ kt at 250 mb) will likewise develop from the southern/central
Plains across the mid MS Valley by Tuesday night. Pronounced
large-scale forcing for ascent preceding the mid/upper-level trough
will encourage a surface low to deepen as it develops northeastward
from the central High Plains to the Upper Midwest by late tonight. A
cold front attendant to this low will sweep quickly eastward across
the southern Plains through the day. This front should reach parts
of the OH/TN Valleys into the Southeast by early Wednesday morning.
...Lower to Mid Mississippi Valley... South-southwesterly low-level
winds will continue to transport Gulf moisture northward this morning
across parts of central/east TX and the lower MS Valley. Latest
short-term guidance is in reasonable agreement that low to mid
50s surface dewpoints should extend as far north as northern
MO and southern/central IL by this evening. Greater low-level
moisture characterized by mid 60s to near 70 F surface dewpoints
will likely remain confined farther south to parts of AR/LA/MS and
east TX. At least two corridors of isolated to scattered severe
thunderstorms may occur today/tonight: one in close proximity to the
mid-latitude cyclone from MO northeastward into eastern IA and IL,
and the other from AR to the Mid-South, possibly extending as far
south as southern/central MS.
Convection should develop along/ahead of the front across MO by late
afternoon/early evening as strong ascent overspreads this region.
Even though low-level moisture should be somewhat more limited with
northward extent, temperatures should rapidly cool at mid-levels as
the upper trough approaches. MLCAPE of 250-750 J/kg should develop by
the time convective initiation occurs, with some guidance suggesting
MLCAPE may reach near 1000 J/kg. Very strong shear owing to rapidly
increasing wind speeds through the cloud-bearing layer suggest
supercells will be possible initially, with both a damaging wind and
isolated tornado threat. Isolated large hail may also occur early in
the convective life cycle given the modestly steepened lapse rates
and very cold temperatures aloft. A small bowing cluster should
develop by late evening and quickly race northeastward into parts
of IL, with mainly a damaging wind risk possibly continuing into
early Wednesday morning as far east as western IN.
A somewhat separate area of convection may form across the open
warm sector in AR and the lower MS Valley by late afternoon owing
primarily to low-level warm air advection and weak confluence along
a pre-frontal trough. Very strong effective shear (60+ kt) and
500-1000 J/kg of MLCAPE will support supercell structures with any
storms that can form in this regime. Isolated instances of damaging
winds and a couple tornadoes should be the main threats with this
convection. There is some uncertainty with overall coverage through
early evening, particularly with southward extent across LA and
southern/central MS, as these areas will remain displaced to the
south of the stronger large-scale ascent. Still, some increase in
thunderstorm coverage with an isolated severe threat may occur late
in the period (early Wednesday morning) as the surface cold front
approaches and a 35-50+ kt southwesterly low-level jet remains over
this region.
..Gleason/Nauslar.. 11/26/2019
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234
AM CST Tue Nov 26 2019
Valid 271200Z - 281200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY... Showers and a few/embedded thunderstorms are expected
over parts of the Northeast/Great Lakes, portions of the central
Gulf Coast region, and the California/Nevada vicinity on Wednesday.
...Discussion... A high-amplitude upper flow field is progged
across the U.S. Wednesday, as a pair of upper cyclones -- one east
and one west -- affect the CONUS through the period.
The first low -- a large vortex initially centered over Oregon
vicinity -- is expected to dig slowly southward across northern
California through the period. The second feature is forecast
to move rapidly eastward with time, from the Upper Midwest to New
England. As this low advances, while the other lingers near the
West Coast, an enlarging/amplifying ridge will gradually evolve
across the central and southeastern portions of the country.
At the surface, a low will track eastward largely in tandem
with the parent upper cyclone, while a trailing cold front moves
rapidly eastward across the eastern third of the country and then
offshore/into the western Atlantic. In the west, a broad/weakening
low is expected to drift across the Oregon/California/Nevada area
through the period.
Rain -- with a few embedded/occasional thunderstorms -- is forecast
to spread from the Upper Great Lakes region across the Northeast/New
England through the period, as the surface low and associated upper
system traverse this same area. Meanwhile, showers -- and a few
thunderstorms over the Gulf Coast states -- should be ongoing early
in the period along the trailing from the Ohio Valley to the mouth
of the Mississippi. The frontal convection should diminish with
time, as large-scale subsidence/ridging aloft increases.
In the West, showers and embedded/occasional lightning will also
affect a large region from Oregon/Idaho across the Great Basin
and into California, in conjunction with the digging upper low.
Finally, rain/rain showers are progged to spread northeastward out
of Mexico into the Southwest, and eventually expand into parts of
the central and southern Plains, through the end of the period.
...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5%
- None Hail: <5% - None
..Goss.. 11/26/2019
+----------------------------------------------------------------------------+
It has been observed that one's nose is never so happy as when it is thrust
into the affairs of another, from which some physiologists have drawn the
inference that the nose is devoid of the sense of smell.
-- Ambrose Bierce, "The Devil's Dictionary"
//////////////////////////////////////////////////////////////////////////////
Read previous mail | Read next mail
| |
