Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/03/22
Area Forecast Discussion
National Weather Service Charleston SC
909 PM EST Wed Feb 2 2022
.SYNOPSIS...
A cold front will move through the area late in the week
followed by an offshore low pressure system bringing unsettled
weather for much of the weekend. Drier weather will then
prevail late in the weekend into early next week as high
pressure moves into the region.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
This evening, KCLX has detected a persistent band of light
showers over the Savannah River with isolated returns around the
SC coast. The updated forecast will maintain SCHC PoPs across
portions of the GA and SC Coastal Plain into the late night
hour. In addition, a patch of very low stratus and fog has
pushed over Charleston County from the near shore waters. A
couple of locations near the coast have reported some light fog
or mist this evening. Based on the satellite trends, the mention
of patchy fog over the nearshore waters and adjacent coast will
remain into the late night hours. Temperatures under the mostly
cloudy/cloudy sky and steady east winds have been slow to cool
this evening. Low temperatures are expected to range in the mid
50s tonight.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Thursday: One last "quiet" weather day is expected. While there will
be an uptick in moisture, expect land areas to remain dry. High
temperatures will likely be in the 70s but could be disrupted by
extensive cloud cover, leading to slightly cooler temps. Low
temperatures will be in the upper 50s to low 60s.
Friday and Saturday: A cold front will pass through the region on
Friday and into Saturday morning as an upper level trough travels
eastward across the U.S. PWATs will gradually increase early Friday,
remaining above 1.5" through at least early Saturday. With plentiful
moisture across the region and decent isentropic lift due to the
passage of shortwave energy, showers are likely to persist much of
Friday and into Saturday morning. For timing, inland areas should
see showers beginning around daybreak Friday, with coastal counties
seeing showers by mid-day. While there could be a few rumbles of
thunder, instability will be lacking so have decided to leave any
mention of thunderstorms out at this time. By daybreak Saturday,
most areas should be dry for a few hours before another low pressure
offshore edges closer to the area and showers slowly develop across
coastal areas.
Otherwise, high temperatures will be in the 70s on Friday then about
20 degrees lower on Saturday. Lows on Friday night will be in the
40s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Overnight Saturday, a coastal low will shift across the coastal
waters, advecting plentiful moisture onshore. With shortwave energy
and isentropic lift, another round of showers will be possible into
Sunday morning. There is still a bit of uncertainty in the timing
and the extent of QPF will largely depend on how quickly the coastal
low shifts eastward and away from the area. In regards to p-type,
there are some indications that some areas could see freezing rain
or a snow/sleet mix. Due to the vast model differences, have decided
to leave out any mention and maintain only rain showers in the
forecast. Thereafter, high pressure will build into the region and
the area should be dry through mid-week.
High temperatures will be in the 50s to 60s each day. Lows will be
coldest Sunday morning and then warm slightly each day.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Prior to the 0Z TAFs, KCLX detected a cluster of light showers
over KSAV. HRRR indicates that the light showers will drift
north, possibly reaching the vicinity of KJZI and KCHS by 3Z.
Otherwise, conditions will feature steady ESE winds and VFR
ceilings. The combination of a 3-4 mb pressure gradient and
mixing between 2.5-3 kft should yield gusty south winds Thursday
afternoon, with gusts ranging from 18 to 24 kts. The wind gusts
are expected to end around sunset.
Extended Aviation Outlook: Periodic flight restrictions will be
possible at all terminals through the weekend due to low clouds and
showers. VFR should then return on Monday.
&&
.MARINE...
Tonight: It is possible that rounds of sea fog could occur near
the coast through most of the night. At this time, the forecast
will mention patchy fog into the late night hours.
Easterly winds will continue to veer to the southeast
into the evening. Wind speeds overnight should generally top
out in the 10-15 knot range, though a solid 15 knots is likely
in the outer portions of the Charleston County waters and the
outer Georgia waters. Seas will remain elevated through the
period thanks to the onshore flow, averaging 3 to 5 feet.
Thursday through Monday: Southerly flow will prevail on
Thursday and Friday ahead of an approaching cold front. Then,
switch to east northeast for the rest of the period. Seas will
gradually increase, with winds picking up late Thursday. Small
Craft Advisories will likely be needed through at least Friday
night. Thereafter, there are hints of another round of SCA`s
over the weekend.
With a moist air mass in place, sea fog will be possible Thursday
night into Friday night. Although, winds could ultimately be too
strong to support any development.
&&
.TIDES/COASTAL FLOODING...
Minor coastal flooding is expected along coastal Charleston/Colleton
Counties during the morning high tide on Thursday. With strong
northeast winds through the weekend, additional coastal flooding
could occur with the late Saturday night high tide.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...NED
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Corpus Christi TX
531 PM CST Wed Feb 2 2022
.AVIATION...
A cold front moving through the Hill Country will move into South
Texas this evening and through the area by shortly after
midnight. Showers will be possible ahead of and then in the wake
of the front. Strong north winds will also develop behind the
front and persist through the day Thursday. MVFR to IFR conditions
develop this evening and continue through the end of the period
as well. There is a chance that some freezing precipitation could
occur...mainly for northern terminals (COT/VCT) late in this
forecast. This will depend on moisture lingering long enough to be
around after temps drop. Confidence is not high enough at this
time to include in the TAFs, but this may need to be added with
future forecast issuances.
&&
.PREV DISCUSSION... /Issued 427 PM CST Wed Feb 2 2022/
SHORT TERM (Tonight through Thursday Night)...
Arctic front as of 4 PM stretched from near Eagle Pass to La Grange
and is on track to reach our northern tier of counties just before
sunset. An axis of rich PWATs around 1.5" was draped over the
Coastal Plains and Victoria Crossroads with an area of shallow
convection just north of our area. This axis is likely to see an
uptick in showers and eventually some thunderstorms, especially as
the front enhances convergence this evening and overnight. FROPA
timing was bumped up to around midnight at Corpus Christi in line
with the faster HRRR which has been performing well so far. Decent 6-
hr pressure rises of 6-9mb will follow the front and aid in
northerly gusts as high as 40 mph along the coast where a Wind
Advisory has been issued.
Precip overall should be enhanced the most along the front, and
then tapering in coverage by early Thursday morning as isentropic
downglide ensues. Despite widespread post-frontal stratus, this
drying is much more pronounced among the latest hi-res and global
models. PoPs consequently were tapered back to slight chance
across the Coastal Plains Thursday morning and afternoon. However,
farther west models are keying on a renewed area of isentropic
ascent and elevated Fn forcing. This should result in a band of
stratiform rain that eventually mixes with and changes to sleet
and some freezing rain as the afternoon wears on. Soundings over
the northern Brush Country Friday afternoon reveal enough wet-bulb
cooling beneath the stratus to support a deepening freezing layer
up to 2000 ft thick at times, so this would certainly yield some
sleet provided enough saturation remains aloft within a
considerable warm nose.
Even though surface temps should remain above freezing for most/all
of Thursday, opted to hoist a Winter Weather Advisory area wide as
temps will be cooling below freezing before sunset over our northern
counties, and then elsewhere overnight all the while this band of
saturated ascent moves slowly E-NE. This Advisory was chosen over a
Warning as wintry accumulations should not be widespread, but rather
more spotty/localized. Coordination with WPC and evaluation of
HREF icing potential favors some spots seeing a very light glaze
of ice tomorrow night through early Friday morning. Am inclined to
believe we`ll see more sleet than freezing rain, especially as
temps have been trending colder and this sub-freezing layer
deepens.
Wind chills by Thursday evening will likely flirt with 15 degrees or
slightly colder area wide, so a Wind Chill Watch was also issued
through Friday morning. Low temps by Fri morning are looking a bit
more marginal for a Hard Freeze Watch, so opted for just a freeze
headline region wide with a few spots across our northern tier
potentially dropping to 25 or lower for a few hours.
LONG TERM (Friday through Wednesday)...
A cold start to the long term as temperatures fall into the mid to
upper 20s across South Texas. Residual moisture in wake of the front
with PWATs remaining above normal (>0.8") and low to mid-level bands
of energy ahead of an approaching trough, could lead to lingering
light bands of wintry mix Friday morning. Soundings still indicate
saturation occurring below the DGZ, limiting ice crystal
availability, with a warm nose below resulting in all liquid
droplets. These liquid droplets, some supercooled, will enter a
deeper low-level cold layer allowing enough time for droplets to
freeze into ice pellets/sleet as it reaches the below freezing
surface. Little to no sleet accumulation is expected over most
areas, but it is worth noting the potential for some higher local
sleet accumulations if bands persist over the same area. At this
time, greatest concern lies from the Brush Country to the northern
Victoria Crossroads but bands could shift further south and east
through the morning as the trough aloft shifts eastward. Drier air
filters in in the afternoon as the favorable lift dynamics aloft
shifts eastward, resulting in dry conditions to dominate Friday
afternoon through at least Sunday night.
A reinforcing surge of high pressure pushes through Monday as a
positively tilted trough with an amplified mid-level trough
progresses across Texas Monday through Tuesday. This is only
expected to result in increase cloud cover and stronger winds over
waters as moisture remains extremely limited with PWATs generally
0.5" or less. However, this will need to be closely monitored over
the next several days as an earlier return of onshore flow and
therefore increasing moisture, will result in rain chances. At this
time, only included slight chances of rain over the southern portion
of the CWA Sunday night into Monday. Onshore flow is expected to
return Wednesday as surface high pressure shifts eastward over the
northern Gulf of Mexico.
Temperatures will finally go above freezing Friday afternoon with
highs in the upper 30s, struggling to exceed 40. Freezing nights
with temperatures from the mid 20s to low 30s are expected to
continue Friday night and Saturday night. Following nights will
remain cold with lows in the 30s to around 40 as offshore flow
continues. Highs on Saturday "warm" into the mid 40s to low 50s,
then increase into the mid 50s to around 60 Sunday through Tuesday,
widespread 60s on Wednesday as onshore flow returns. A Freeze
Warning will be likely Friday night and Saturday night with a Hard
Freeze potential over the northern tier counties on Friday night.
Wind chills in the teens Friday morning has led to a Wind Chill
Watch. Additional Wind Chill Advisories and Warnings will likely be
needed Friday night and Saturday night.
MARINE...
Some sea fog may develop this evening before a strong cold front
sweeps south. This front should reach the northern coastal waters
around midnight, then exit the southern open waters before 6 AM.
Scattered to numerous showers and a few thunderstorms are expected
along and ahead of this front, before tapering in coverage through
the day on Thursday. Weak to moderate onshore flow ahead of the
front will become strong overnight with Gale force gusts likely
through the day on Friday. A Gale Warning continues through
Friday afternoon for the coastal waters. Areas of light rain will
linger over the Gulf waters Thursday night with a possibility of
rain mixing to freezing rain or sleet early Friday morning over
the bays and possibly into the near shore waters.Chances for rain
will diminish through Friday night as drier air filters in. Strong
north winds will continue through Friday night, becoming moderate
Saturday. Winds will become weak to moderate out of the northeast
Saturday night into Sunday. Northeast winds will strengthen to
moderate Sunday afternoon then to moderate to strong Sunday night
through Monday as a reinforcing surge of high pressure pushes
through the waters. Winds decrease to weak to moderate Tuesday
then become onshore by Wednesday as high pressure shifts off to
the east.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 42 44 29 39 28 / 70 30 20 20 10
Victoria 38 39 25 37 26 / 80 50 30 20 0
Laredo 42 42 30 41 30 / 60 50 20 10 0
Alice 41 44 29 39 26 / 70 30 30 20 10
Rockport 42 43 30 40 29 / 80 40 20 30 10
Cotulla 38 39 26 41 26 / 80 80 20 10 0
Kingsville 41 45 30 40 27 / 70 30 20 20 10
Navy Corpus 44 45 30 40 32 / 70 40 20 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Freeze Watch from Thursday afternoon through Friday morning For
the following zones: Aransas Islands...Bee...Calhoun
Islands...Coastal Aransas...Coastal Calhoun...Coastal
Kleberg...Coastal Nueces...Coastal Refugio...Coastal San
Patricio...Duval...Goliad...Inland Calhoun...Inland
Kleberg...Inland Nueces...Inland Refugio...Inland San
Patricio...Jim Wells...Kleberg Islands...La Salle...Live
Oak...McMullen...Nueces Islands...Victoria...Webb.
Freeze Watch from Friday evening through Saturday morning For
the following zones: Aransas Islands...Bee...Calhoun
Islands...Coastal Aransas...Coastal Calhoun...Coastal
Kleberg...Coastal Nueces...Coastal Refugio...Coastal San
Patricio...Duval...Goliad...Inland Calhoun...Inland
Kleberg...Inland Nueces...Inland Refugio...Inland San
Patricio...Jim Wells...Kleberg Islands...La Salle...Live
Oak...McMullen...Nueces Islands...Victoria...Webb.
Winter Weather Advisory from noon Thursday to noon CST Friday
For the following zones: Aransas Islands...Bee...Calhoun
Islands...Coastal Aransas...Coastal Calhoun...Coastal
Kleberg...Coastal Nueces...Coastal Refugio...Coastal San
Patricio...Duval...Goliad...Inland Calhoun...Inland
Kleberg...Inland Nueces...Inland Refugio...Inland San
Patricio...Jim Wells...Kleberg Islands...La Salle...Live
Oak...McMullen...Nueces Islands...Victoria...Webb.
Wind Advisory from 3 AM Thursday to 6 AM CST Friday For the
following zones: Aransas Islands...Calhoun Islands...
Coastal Aransas...Coastal Calhoun...Coastal Kleberg...
Coastal Nueces...Coastal Refugio...Coastal San Patricio...
Kleberg Islands...Nueces Islands.
Wind Chill Watch from late Thursday night through Friday morning
For the following zones: Aransas Islands...Bee...Calhoun
Islands...Coastal Aransas...Coastal Calhoun...Coastal
Kleberg...Coastal Nueces...Coastal Refugio...Coastal San
Patricio...Duval...Goliad...Inland Calhoun...Inland
Kleberg...Inland Nueces...Inland Refugio...Inland San
Patricio...Jim Wells...Kleberg Islands...La Salle...Live
Oak...McMullen...Nueces Islands...Victoria...Webb.
GM...Gale Warning from 3 AM Thursday to 6 PM CST Friday For the
following zones: Bays and Waterways from Baffin Bay to Port
Aransas...Bays and Waterways from Port Aransas to Port
O`Connor...Coastal waters from Baffin Bay to Port Aransas
out 20 NM...Coastal waters from Port Aransas to Matagorda
Ship Channel out 20 NM...Waters from Baffin Bay to Port
Aransas from 20 to 60 NM...Waters from Port Aransas to
Matagorda Ship Channel from 20 to 60 NM.
&&
$$
PH/83...AVIATION
Area Forecast Discussion
National Weather Service Indianapolis IN
947 PM EST Wed Feb 2 2022
.Forecast Update...
Issued at 947 PM EST Wed Feb 2 2022
Radar was showing a broad area of light radar returns embedded with
some slightly stronger echoes near and northwest of a 925 millibar
frontogenesis axis from just west of Louisville to near Richmond and
Dayton. The mixed precipitation has changed to snow from roughly
near and northwest of a Muncie to Indianapolis to Washington line
late this evening with cold advection advancing from the north and
temperatures below freezing at most locales.
Model time sections, upward vertical motion progs, the HRRR and
radar and satellite trends all support lowering PoPs from northwest
to southeast until after 09z when another wave along the front to
the southeast helps generate accumulating snow. For the rest of the
evening and early overnight, weak but effective nose of warm air
aloft will keep southeastern sections in a freezing rain and sleet
mix. This will result in extremely slick untreated roadways and
sidewalks. After that, look for the large area of snow, currently
over the Ozarks to spread northeast into central Indiana after 09z
with 1 to 2 inches of additional snowfall over areas near and north
of Interstate 70 and additional ice amounts around 0.05 inches over
southeastern Indiana.
&&
.Short Term...(This evening through Thursday night)
Issued at 228 PM EST Wed Feb 2 2022
...SIGNIFICANT WINTER STORM CONTINUES THROUGH THURSDAY...
As of early this afternoon, the rain/snow transition was located
along a rough line from north of Terre Haute through Lebanon and
south of Kokomo with all snow to the northwest. Synoptically, the
surface low pressure is moving into southern Indiana from southern
Illinois with the surface winds across much of central Indiana north
of I-70 now northerly. For the latest thoughts on the mesoscale
environment, please see the Mesoscale portion of the discussion
above, further information below will be on the overall system and
impacts.
No major changes have been made to the forecast with the forecast
amounts still lining up closely with previous forecasts. The main
area of concern still is across the southern counties and the
transition of precipitation type tonight into tomorrow. Model
soundings continue to slightly waffle on how strong the warm nose
will get today into tonight and how quickly that erodes late tonight
into tomorrow morning.
Current thoughts are the 18Z RAP handles it well with the nose
between 900mb and 775mb with peak temperature around 2.5C this
evening which will erode to 0 by tomorrow morning with slower
transitions across the far southeastern counties. This warm nose
will be enough for a period of freezing rain tonight before all
sleet then snow later in the day. Across the I-70 corridor and to
the north, all snow should be the main P-type after the transition
today.
The stronger surface low is expected to move through the lower
Tennessee Valley with the second wave of precipitation late tomorrow
morning into the afternoon hours. An impressive 850mb fgen band
will be spread across the I-70 corridor tomorrow which should be
able to efficiently squeeze out 4-6 inches of snow in a fairly broad
band with a likely more narrow band of higher amounts. The system
then will exit after 00Z with conditions improving afterwards.
Snow amounts remain near previous forecasts with some potential
lower amounts across the northern counties. The bulk of the
moisture advection and forcing looks to remain south of the forecast
area which may limit the overall snow amounts, but do think that the
additional 700mb forcing should be enough to push the amounts into
the 10+ inch range. Significant icing may only occur across the
extreme southeastern portions of the forecast area, but the impacts
of snow/sleet on top of the frozen slush will cause dangerous to
impossible travel conditions at times through Thursday night. Will
be fine-tuning the snow ratios as the colder air moves in causing a
more light/fluffy snow tomorrow compared what`s ongoing.
A secondary but significant concern will be the gusty winds tomorrow
with periods of northerly gusts of 30-40 mph at times. This will
cause blowing snow concerns especially across the northern counties
where the snow will be more light/fluffy compared to the southern
counties. There may be power loss issues across the southern
counties where any ice accumulates ahead of the stronger winds.
&&
.Long Term...(Friday through Wednesday)
Issued at 228 PM EST Wed Feb 2 2022
Highlights:
--Arctic air Friday through Saturday with below zero wind chills
Friday night
--Dry and with a slight warmup early next week
On Friday, central Indiana will experience much colder air as high
pressure from the Canadian Plains builds beneath strong CAA. The
full brunt of the Arctic air wont arrive until Friday night as the
high pressure becomes co-located with a deep upper level trough;
suppressing the atmospheric layer. This in combination with
efficient diurnal cooling and a significant snow depth will push
temperatures near zero with wind chill values around -10 to -15
Saturday morning.
The overall synoptic pattern over the Ohio Valley will return to
broad NW flow with strong ridging over the western US. This will
keep conditions cool and dry through the remainder of the weekend
with no moisture return expected
A slight warm up will ensue early next week, associated with the
emergence of a low level wave. As the wave approaches, the low
level winds will begin to shift to the S/W, advecting a warmer air
mass over the region. Current expectations are for highs in the mid
30s to low 40s. Although this wave will provide some lift, moisture
still remains low, eliminating chances for rain at this time.
Confidence in zero precipitation early next week is low, as
ensembles are varied on the levels of low level moisture.
&&
.Aviation...(00Z TAF Issuance)
Issued at 601 PM EST Wed Feb 2 2022
IMPACTS:
-MVFR and worse flying conditions in both ceilings and
visibilities through the TAF period.
-Snow through most of the TAF period at KLAF and KHUF.
Mix of all possibly precipitation types at KIND changing
to all snow after 03z Thursday. Rain, mixing with freezing
rain and sleet at KBMG after 02z and mixing with snow
after 10z.
-Winds from 010-030 degrees 12 to 17 knots with gusts to near
30 knots.
DISCUSSION:
Prolonged significant Winter storm will result in continued snow
at Lafayette and Terre Haute, a mix at Bloomington and a mix
changing to snow at KIND. The widespread precipitation will be
accompanied by north and northeast winds that will gust to near
30 knots at times and also be poor overall flying conditions
including blowing snow.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 1 AM EST Friday for INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
Update...MK
Short Term...White
Long Term...Updike
Aviation...MK
Area Forecast Discussion
National Weather Service Lubbock TX
527 PM CST Wed Feb 2 2022
.AVIATION...
Light snow currently affecting all TAF sites is expected to come
to an end within the next hour or so. Visbys will likely improve
with the ending of snowfall but CIGS will likely remain in MVFR
category. An upper level storm system approaching the area will
lead to additional snowfall spreading over the area after 06Z
tonight. Flight conditions will deteriorate with the onset of
additional snowfall with IFR possible at times. This second round
of snowfall is expected to end mid to late morning at all TAF
sites but CIGS will remain as MVFR through at least 00Z tomorrow.
&&
.PREV DISCUSSION... /issued 218 PM CST Wed Feb 2 2022/
SHORT TERM...
GOES-East water vapor imagery this afternoon depicts an amplifying,
positively-tilted trough digging into the Desert Southwest with a
series of compact shortwave perturbations embedded within the
broader flow, with the main vorticity lobe located over the Mojave
Desert. Another ill-defined shortwave perturbation was also detected
over northern Chihuahua, trailing the developing baroclinic leaf
across the southern Great Plains. At the surface, the strong CAA
continues as the cA airmass continues to infiltrate the region.
Surface temperatures are currently ranging between the upper teens
to upper 20s across the extreme southern TX PH into the southern
South and Rolling Plains, respectively; with the wet-bulb zero
line located well to the south and east of the CWA. A report of
0.5" of sleet was noted in Aspermont as of 1845Z, and confirms the
recent trends in WSR-88D imagery with slight reductions in rhoHV
coupled with enhanced ZH in the mid-levels, indicating that the
warm nose (>=0 deg C) aloft is almost below freezing. Further
south, the 18Z observed RAOB from WFO MAF indicated a more-
pronounced warm nose with 850-700 mb southwesterly winds at around
20 kt. The expectation is for the warm nose to erode entirely
across the southern portions of the CWA over the next few hours
due to wet-bulb cooling within the drier mid-levels as large-scale
forcing for ascent increases ahead of the approaching shortwave
trough, with RADAR echoes continuing to fill in on higher
elevation scans per recent WSR-88D data out of Lubbock.
The frontogenetically-forced band of wintry precipitation over the
southeastern portions of the CWA will continue to intensify as the
positively-tilted trough amplifies and pivots eastward. As the
vertical thermodynamic profiles fall below freezing entirely around
22-23Z (while also saturated with respect to water, and therefore
supersaturated with respect to ice), the corridor of strong theta-e
advection as observed by the 18Z MAF RAOB and indicated on forecast
RAP soundings will result in a favorable environment for dendritic
growth across the southeastern Rolling Plains. Mixing ratios within
the dendritic growth zone (DGZ) may approach 2.0-2.2 g/kg and
temperatures near 30-31 deg F beneath the DGZ, favoring the
potential for large aggregates (snowflakes clumping together) which
may result in short-fused period where hourly snowfall rates
approach up to 1.0" per hour before the FGEN band propagates
eastward. Total snow accumulations of 5-7 inches are still expected
across the southeastern Rolling Plains, and a Winter Storm Warning
remains in effect for Kent, King, and Stonewall Counties through
04/00Z. Further west, light snow has been reported southwest of
Lubbock by NWS employees, and light snow associated with the western
periphery of the FGEN band and moist, isentropic ascent ahead of the
ejecting shortwave trough(s), will continue across the Caprock
throughout the remainder of the afternoon and evening.
A lull in snowfall is also forecast to occur tonight, as the FGEN
band moves eastward prior to the arrival of the ejecting shortwave
trough with dry air intrusion in the mid-levels. However, moistening
of the 300-320 K theta surfaces will increase quickly after midnight
from southwest-to-northeast, with widespread, light snowfall
expected to re-develop area-wide. Hourly snowfall rates will be low
overnight across the Caprock, owing to an increasingly unfavorable
environment for dendritic growth due to the colder temperatures
throughout the vertical profile and as vapor densities decrease as
the mid-level jet streak arrives, therefore resulting in the
generation of smaller polycrystalline habits (i.e. plate-like to
perhaps columnar-like compared to aggregates as mentioned in the
previous paragraph). Total snow accumulations of 1-4 inches are
expected across areas within the Winter Weather Advisory across the
Caprock and Rolling Plains. The Winter Weather Advisories and Winter
Storm Warning will continue through 04/00Z (6 PM CST Thursday),
though earlier cancellations are not out of the question due to the
progressiveness of the approaching trough, which is forecast to
remain open with no closed low developing.
Temperatures will crater into the single-digits to lower teens
across the region tonight as north-northeasterly winds persist at
around 20 mph. The combination of the blustery winds and very cold
temperatures will result in wind chill values ranging between 5 to
15 deg F below zero. A Wind Chill Advisory will initially be in
effect at midnight CST for the extreme southwestern Texas Panhandle
and northern South Plains, before extending south and east to
include the rest of the South Plains and the majority of the Rolling
Plains, and will expire at noon CST Thursday. Very cold conditions
will continue into the daytime tomorrow, with highs struggling to
rise above the teens area-wide with blustery winds out of the north.
Sincavage
LONG TERM...
Cold 1040 millibar surface high pressure ridge will span the area
Thursday night into Friday, with surface northerly flow gradually
tapering. Wind speeds will be key for possible need of another
Wind Chill Advisory for Thursday night into Friday morning, with
wind speed of 10 mph or higher required criteria. At this point
appears wind speeds very well will be 10 mph or higher at least
Thursday evening before tapering and ambient air temperatures
Thursday night will be single digits most of the area. We will
defer issuance of this possible Wind Chilly Advisory until
confidence in wind speeds improves.
Otherwise, dry air on Friday with more sunshine and light winds
should allow modest warming, at least near if not slightly above
freezing for most of the area. The upper level low pressure trough
should pass east early in the day. Leftover snowpack will have a
say in high temperatures for Friday, and at this point best guess
is much of the area will have at least a light accumulation on the
ground to start the day. Another cold night will follow Friday
night, single digits to lower teens, before better warming into
the 40s Saturday as westerly flow aloft increases. Another upper
trough will dip across the area Sunday along with renewed light
northerly flow. This will limit warming potential Sunday with
highs expected to be similar to Saturday, still around 10 degrees
less than normal.
Better warming and continued dry weather expected early to middle
of next week as we remain generally under northwest flow but
absent of strong frontal systems. Temperatures should recover back
to if not a little warmer than normal during much of the work
week. RMcQueen
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 PM CST Thursday for TXZ038-043-044.
Winter Weather Advisory until 6 PM CST Thursday for TXZ021>037-
039>042.
Wind Chill Advisory from midnight tonight to noon CST Thursday
for TXZ021>024-027>030.
Wind Chill Advisory from 3 AM to noon CST Thursday for TXZ025-
026-031>037-039>041.
&&
$$
01
Area Forecast Discussion
National Weather Service Mobile AL
539 PM CST Wed Feb 2 2022
.AVIATION...
00Z issuance...Patches of rain over the area diminish in coverage
overnight. Showers and thunderstorms are expected to develop over
the area on Thursday with the highest coverage during the
afternoon hours generally along and west of I-65. IFR to MVFR
ceilings near the coast spread inland overnight with LIFR
conditions possible late tonight into mid Thursday morning.
Southeasterly winds around 10 knots become southerly 15 to 20
knots on Thursday. /29
&&
.PREV DISCUSSION... /issued 416 PM CST Wed Feb 2 2022/
NEAR TERM UPDATE /Now Through Thursday/...Latest Hi-Res model data
indicate that it is likely that the showers that are currently most
numerous over the western half of our forecast area will lift to the
north and decrease across the region late this afternoon and early
this evening (before returning from the west late tonight into
Thursday). Will maintain the High PoPs over the western half of
forecast area late this afternoon and into the early evening,
although a few sprinkles of light rain will also be possible further
east as well. There could also be a few rumbles of thunder near the
coast this evening, but this potential is rather low as deep
convection is not anticipated. PoPs will lower somewhat, for a while
anyway, this evening before increasing from the west late tonight
and then especially during the day on Thursday. Moderate to strong
southeasterly flow (gusting up to around 25 knots at times) will
continue this afternoon, bringing warmer air in from out over the
Gulf.
Looking ahead, still looks to be an active day Thursday, especially
during the afternoon and evening hours as showers and thunderstorms
move in from the west. Instability, which was rather limited today,
improves on Thursday, especially over portions of southeast
Mississippi and southwestern Alabama. SBCAPE values trend higher to
400-900 J/kg with some pockets of instability up to near 1300 J/kg
possible. Plenty of favorable shear will be present over the area on
Thursday as the 850 mb jet increases from 30-35 knots in the morning
to closer to 45 to 50 knots (perhaps a little more depending on what
model you choose) in the afternoon. Bulk shear increases to 35-45
knots over the western third of the area Thursday morning (recalling
that 30-40 knots favors bowing thunderstorm structures) then these
shear values spread further east to include much of the remainder of
the area in the afternoon. 0-3 km helicity values of 250-350 m2/s2
will be present through much of the day as well. Limiting factor
could be only minimally supportive mid level lapse rates, highest
values only around 6 C/KM. SPC has our entire forecast area
outlooked with a Marginal Risk of severe weather on Thursday
(afternoon and evening), but there is some potential for this to be
upgraded to a Slight Risk (particularly over the western half of our
forecast area, approx along and west of I-65). We will continue to
monitor and coordinate this potential. Straight line winds will be
the most likely threat with the broken line of thunderstorms as they
move east across the region, but we have noted that recent runs of
the HRRR indicate Sig Tor Parameters of 1.0 to 1.5 along with nicely
curved hodographs in the lowest levels, so there could be a low end
tornado potential as well.
High rainfall rates will accompany the thunderstorms on Thursday,
especially along and west of I-65, where up to 2 inches of rainfall
(locally double that amount) could be possible through Thursday
afternoon, which could lead to isolated flash flooding issues. We
will monitor for the need of a Flash Flood Watch for this area, but
will hold off for now since its difficult to assess just where the
heavier rains will occur. A High Surf Advisory is in effect through
the period for large breaking waves of 5 to 8 feet in the surf zone,
and a High Risk of Rip Currents is also in effect. Wind gusts
occasionally to near 30 mph are possible mainly near the coast
during the daytime hours both today and again on Thursday, but below
Wind Advisory criteria. Another concern is the potential for minor
coastal flooding over northern Mobile Bay (primarily along the
Causeway) during the time of high tide tonight, but have continue to
hold off on issuance of a Coastal Flood Advisory as observed tide
heights have been running consistently a bit below forecast levels
and forecast levels themselves have come down slightly from earlier
and are expected to be just below minor coastal flood criteria.
Finally, it appears that conditions will become favorable for dense
fog to develop late tonight and persist through Friday morning as
higher dewpoints overspread the cold waters of Mobile Bay and
Mississippi Sound. A Marine Dense Fog Advisory has been issued for
these areas. The dense fog potential will likely increase on
Thursday and Thursday night across a wider area across the coastal
waters and and spread inland as well, therefore the Dense Fog
Advisory area will likely need to be expanded on Thursday.
Mild temperatures will continue in the near term as the front
approaches from the west. Lows tonight are expected to mainly be in
the lower 60s. On Thursday, even with overcast conditions the strong
onshore flow out of the south will allow daytime highs to rise into
the lower 70s across the entire area. /12
SHORT TERM /Thursday night Through Saturday night/...An upper
level shortwave trough centered over the CO/NM/OK/TX border moves
east against an upper trough stretching along the East Coast. This
upper ridge slows the eastward progression of the upper trough such
that by Sunday morning, the trough has moved to the East Coast and
the ridge has pushed over the open Atlantic. Some guidance has been
advertising the upper trough organizing into a closed low as it
moves over the ArkLaTex, with a bit slow transit, but this has been
inconsistent between models and run to run the last several days. A
strong cold front has begun moving over the northwestern quarter of
the forecast area by 00z Friday, and south of the forecast area by
18z Friday. Timing of the fropa has been relatively consistent the
last few days, with a few hours plus or minus difference.
There are several items to discuss in the Short Term. The first is a
lingering chance of strong to severe storms along and southeast of I-
65 as the front crosses the area. With marginal instability (MLCapes
starting the evening around 500-700J/kg) and wind shear (Bulk Shear
values of 40-60kts) decrease with the loss of any daytime heating.
Mid and upper level jet support moves off, so am expecting the risk
of any strong to severe storms to diminish in the evening. Low level
helicities are good, with 0-1km helicities ranging from 150-300
m^2/s^2, so may see a few low topped spinners mixing in.
Second, looking at water issues, low/mid level flow has become more
parallel to the front, easing any over-running enhancement to
rainfall production except of areas southeast of I-65, and even this
quickly decreases. Still will have to monitor for water issues in
poor drainage areas, especially if some localities see training
cells.
Third, with continues warm moist air overflowing cooler Gulf waters
near the coast (SSTs in the upper 50s to low 60s over open waters,
low to mid 50s in protected waters), dense advection fog may be an
issue over our coastal counties and near shore waters ahead of the
slowly advancing front.
Fourth, looking at the possibility of any freezing/frozen
precipitation on the backside of the retreating rain shield Friday
night, guidance has been consistently ending the rain before any
portion of the forecast area sees a sufficiently cooler boundary
layer for freezing/frozen precipitation.
Lastly, looking at temperatures, as the cooler air overspreads the
forecast area behind the front, Thursday night will see a gradient
in low temperatures, with mid to upper 30s well northwest of the
Alabama River to low to mid 50s well southeast of I-65. Friday will
see the same nw-se gradient, with highs ranging from the mid 40s
well northwest of the Alabama River to mid to upper 50s well
southeast of I-65. Friday and Saturday nights will see a return of
freezing temperatures to the forecast area, with upper 20s to upper
30s expected Friday night and mid 20s to mid 30s expected Saturday
night. /16
EXTENDED TERM /Sunday Through Wednesday/...An upper level
shortwave will quickly sweep across the Southeast on Sunday.
Southwesterly flow aloft then sets up in its wake as a positively
tilted longwave trough begins to dig across the central CONUS.
Ensembles are in decent agreement with the base of this upper
trough cutting off over the Desert Southwest while the remainder
of the upper trough moves east early next week with shortwaves
embedded within. In regards to deterministic guidance, there is
still quite a bit of uncertainty with the overall strength and
progression of this upper trough. At the surface, high pressure
builds into the region from the northwest on Sunday as a surface
low tracks along the Eastern Seaboard. There are indications of a
cold front sagging south on Monday in association with the upper
trough, but current guidance has the front dissipating before it
reaches the local area. Overall, surface high pressure looks to
dominate for much of the period which will maintain dry
conditions. The passing shortwaves will also help to reinforce
cooler air into the region. Highs on Sunday and into early next
week range from the mid to upper 50s. Lows are expected to mainly
be in the 30s inland (potentially a few areas of upper 20s in
northern portions of the CWA) to lower 40s along the immediate
coast. /14
MARINE...Strong southeasterly winds with high seas will continue
through Thursday as a cold front approaches from the west. These
winds and seas will bring hazardous conditions for small craft and a
SCA remains in effect. Some gusts to near gale force could be
possible over the open Gulf waters. Winds and seas will be locally
higher near showers and thunderstorms that accompany the frontal
passage. The front moves across and then east of the marine area
Thursday night with a strong northerly flow and higher seas
persisting in it`s wake through Friday night before gradually
diminishing. In advance of the front, conditions will become
favorable for periods of dense sea fog over the near shore Gulf
waters and area bays and sounds. /12
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...High Rip Current Risk through late Friday night for ALZ265-266.
High Surf Advisory until noon CST Friday for ALZ265-266.
FL...High Rip Current Risk through late Friday night for FLZ202-204-
206.
High Surf Advisory until noon CST Friday for FLZ202-204-206.
MS...None.
GM...Small Craft Advisory until midnight CST Thursday night for
GMZ630>636.
Dense Fog Advisory from midnight tonight to 9 AM CST Friday for
GMZ630>632.
Small Craft Advisory until 6 AM CST Saturday for GMZ650-655-670-
675.
&&
$$
This product is also available on the web at:
http://weather.gov/mob
Area Forecast Discussion
National Weather Service Pueblo CO
640 PM MST Wed Feb 2 2022
.UPDATE...
Issued at 630 PM MST Wed Feb 2 2022
Cancelled highlights for most of the plains and El Paso County
this round, as HRRR keeps bulk of accumulating snow south in NM
and the TX Panh. Held onto adv/warnings elsewhere for another hr
or so, as patch of snow in ern Fremont county and over the
Wets/Sangres has been slow to dissipate. Still expect most if not
all highlights for snow will be down by mid-evening.
Given at least partial clearing in spots as subsidence and drier
air spread over the region, suspect min temps may be too warm by a
few degf at many locations, and will likely be dropping overnight
temps with subsequent updates. May also add some zones to wind
chill advisories, as a few mountain locales could see readings of
minus 25-35f overnight.
UPDATE Issued at 530 PM MST Wed Feb 2 2022
Parade of highlight cancellations has begun, as snow has pretty
much ended over the central mountains and upper Arkansas Valley,
so ended the advisory for these areas. Given radar/ob trends on
the plains, suspect we`ll be ending a bigger chunk of highlights
after 01z.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 237 PM MST Wed Feb 2 2022
Key Messages:
1) Snow winding down tonight
2) Very cold minimum temperatures and wind chill threat tonight
Current...The upper low pressure trough axis is located from central
WY into northern AZ, and satellite imagery clearly show the drying
air and clearing skies pushing into northwestern CO as of 2 PM.
Meanwhile, across southeast and south central CO, light to moderate
snow continues to fall under overcast skies with temps hovering in
the 9 to 18 degree range for much of the area.
Tonight...Models agree that the upper trough axis slides east into
central CO tonight, and this should effectively bring a rapid
decrease in snowfall from the northwest to the southeast between 9
PM and midnight, then lingering show showers across the east after
midnight as the upper system continues pushing east. All the current
warnings and advisories will remain in place tonight since
additional snow will fall, but some of the highlights may be dropped
early by the following shift.
The clearing skies, fresh snow cover and extremely cold air already
in place will make for an extremely cold night, and it will not take
much by way of wind to produce dangerous wind chills. Therefore,
decided to issue a Wind Chill Advisory for the San Luis Valley,
northern El Paso County, and Kiowa, Prowers and Baca counties
starting at 9 PM and lasting through 9 AM tomorrow. That is not to
say that it will not be cold elsewhere; it will be cold everywhere,
but those areas will have the highest threat of dangerous, life-
threatening cold conditions. Temps will drop to 10 below to 5 above
for most areas tonight, while the San Luis Valley plummets to 10
below to 15 below zero.
Tomorrow...The storm system pushes east to reach western Kansas and
the OK and TX Panhandles through the day, and save for some isolated
snow showers lingering over the southern mts, much of the forecast
area should see plenty of sun by the afternoon. However, it will
still be a very cold day with high temps only forecast to warm into
the upper teens to mid 20s. Moore
.LONG TERM...(Thursday night through Wednesday)
Issued at 237 PM MST Wed Feb 2 2022
Key Messages...
1) Very cold temps Thursday night.
2) Warming trend set up Friday through Tuesday.
3) Models differ on precipitation, but currently dry conditions are
expected to continue.
Thursday Night-Friday...
With the departure of the previous system and the upper-level trough
moving out of our area, the weather is expected to improve into this
weekend. With clouds clearing out and relatively light winds
expected, radiative cooling combined with the cold air mass already
in place will make Thursday night another bitterly cold experience.
Sub-zero temperatures are anticipated across most of the forecast
area, both mountains and plains. The coldest temps will be over
Kiowa and Prowers Counties, with lows around -10, as well as the San
Luis Valley which could get as low as -20. Conditions are expected
to quickly improve on Friday, with clear skies and high temperatures
warming into the high-20s over the higher terrain and high-30s over
the plains.
Saturday-Sunday...
Moderate northwest flow aloft will set in over the weekend, becoming
more northerly on Sunday. The dry trend in the models solutions
continues, and warming high temperatures will set in over most of
the area. High temperatures over the plains will increase into the
30s over the higher terrain on Saturday, and may hit low-50s over
the plains. Sunday will be similar, if 4-5 degrees cooler out east.
Winds will be a bit breezier from the northwest at the surface
during the afternoon hours. Model solutions begin to noticeably
diverge at this point, with the GFS being a bit more optimistic on
precipitation chances than the EC. The GFS produces a bit of a
stronger disturbance in the upper-level flow as the base of a
positively-tilted trough passes far to the east, bringing a bit of
moisture and isolated snow showers to our southern mountains. The
EC, on the other hand, does not bring in any moisture with this wave
passage and keeps our CWA completely dry. The NBM has some isolated
POPs over the Sangres and San Juans, so stuck with that for now.
Monday-Wednesday...
Upper-level ridging will set in over the area Monday-Tuesday. Model
solutions have slowly begun to converge on the behavior of the
shortwaves embedded within zonal flow for the first half of next
week, but still differ slightly on timing and moisture. Monday will
be dry, warming almost 10 degrees in places compared to Sunday. The
next disturbance to the flow will come Tuesday afternoon as a
shortwave passes a bit north of our area. However, this system still
seems to be lacking in moisture and any precipitation is not
expected at this time. Otherwise, Tuesday will be calm and warmer
than the previous few days by several degrees. Northerly flow and
another disturbance are set up in the model solutions over the
Wednesday-Thursday timeframe, which should increase chances for
precipitation leading into the end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 237 PM MST Wed Feb 2 2022
KALS: Heavier snow bands and LIFR conditions have persisted for most
of the day, but should dissipate over the next few hours, with snow
lightening. However, low stratus clouds are expected to maintain
over the terminal well into the overnight hours. Looking at the
overnight into early morning hours tomorrow, depending on whether
the clouds are able to clear out a bit and radiative cooling can
take over, there could be a transition from low stratus to fog early
tomorrow morning.
KCOS: Light snow will continue over the terminal the rest of today,
limiting flight category to IFR through about 03Z this evening. Snow
will lighten into the early overnight hours, with MVFR improving to
VFR by 06Z. Otherwise, low-level clouds and some stratus will
persist in the area, slowly thinning out into tomorrow morning.
KPUB: Light snow and limited vis will persist with IFR conditions
through around 02Z this evening, with low level clouds slowly
decreasing overnight into tomorrow. Will have to keep an eye on the
potential for fog very early tomorrow morning.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight MST tonight for
COZ069>071-086-088.
Winter Storm Warning until midnight MST tonight for COZ065>068-
072>080-083-087.
Wind Chill Advisory until 9 AM MST Thursday for COZ069>071-084-
095-096-098-099.
&&
$$
UPDATE...PETERSEN
SHORT TERM...MOORE
LONG TERM...GARBEROGLIO
AVIATION...GARBEROGLIO