Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/28/23
Area Forecast Discussion
National Weather Service La Crosse WI
549 PM CST Mon Feb 27 2023
.DISCUSSION...(This evening through Monday)
Issued at 109 PM CST Mon Feb 27 2023
Key Messages:
- Mixed Precipitation Exiting to the Northeast this Afternoon.
- Rain/Snow Mix Likely Tuesday Night Into Wednesday Morning.
- Deepening Surface Low Takes Aim at Upper Midwest for the Latter
Half of the Week.
Today`s Rain & Freezing Rain:
Anomalously moist air mass dropped near 1.5 inches of liquid across
parts of the forecast area this morning. Evident in balloon launches
this morning at the Chanhassen and Davenport forecast offices
beating record PWATs. This has caused rises on local, flashier
rivers, such as the Turkey and Kickapoo. Water vapor imagery and
radar show pronounced dry slot that has eroded precipitation across
from southwest to northeast through the late morning.
Midweek Mixed Precipitation:
A weak mid level wave passes the forecast area Tuesday night into
Wednesday morning, with mixed precipitation impacts expected.
Isentropic upglide within the warm wing perks above 15 ubar/s during
the evening on the 280-290K surfaces. The RAP (27.15Z) suggests
sufficient upper level ice nucleation for much of the area, while
HRRR (27.12Z) and NAM 3 km (27.12Z) remove nucleation in forecast soundings
and frequently flirt below the 0C isotherm. High resolution
ensemble (27.12Z) FRAM guidance suggests a glaze of patchy ice
from freezing rain is possible. Various deterministic guidance
(27.12Z) bifurcates the 925mb 0C isotherm across the forecast
area from east to west as the wave passes. Have continued with a
Rain/Snow mix at the current forecast hour, but as high
resolution models pick up on this passing wave, temporal and
spatial specifications should be sorted.
Snow Likely in Southern Parts of Forecast Area:
The active pattern is expected to continue for the latter half of
the week as an anomalously strong surface low deepens across the
southern Plains into the Mississippi River Valley. At the current
forecast hour, local impacts remain in our south with highest
confidence for measurable snowfall sticking to Grant County. EPS
(27.12Z) confidence (60-80%) suggests a tight gradient of greater
than three inches of snow (10:1 Snow-to-liquid ratios) from the
IA/IL/MO border northeast to Milwaukee. GEFS (27.12Z), lacking as
tight of a gradient comparatively, paints southwest to northeast
>3 inch snowfall (10:1 Snow-to-liquid ratios) increased
confidence (60-90%) from southeast Iowa to Milwaukee. GEFS
solution results in increased snowfall for Boscobel, with most
members forecasting snowfall and 90th percentile of a couple feet.
EPS similarly has most members forecasting snowfall at EPS, with
90th percentile reaching above 1 foot. Lack of consensus on mid
level perturbation in 27.00z cluster analysis emphasizes effect of
surface track on snowfall amounts. Increased consensus expected
in future forecasts.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 548 PM CST Mon Feb 27 2023
LIFR/IFR ceilings will continue at KRST through 28.06z and then
transition to VFR as the cyclonic flow aloft wanes and drier air
moves into the region. The MVFR visibilities will persist through
28.03z and then become VFR.
KLSE will see a brief period of rain and snow through 28.02z. It
may briefly reduce visibilities to MVFR. Ceilings will remain MVFR
through 28.09z and then become VFR for the same reason as listed
for KRST.
&&
.HYDROLOGY...
Issued at 115 PM CST Mon Feb 27 2023
An area of low pressure passing through northern Illinois early this
afternoon brought ample amounts of rainfall across parts of
northeastern Iowa, southeast Minnesota, and southwest Wisconsin.
Record precipitable water values were observed for 12Z RAOBs at
both Chanhassen and Davenport, 0.87 and 1.19 inches, respectively.
Observed rainfall amounts across northeast Iowa range from around
1 to 1.5 inches. This has led to rises in rivers, with forecasts
along the Turkey River climbing into Minor Flood Stage. Smaller
tributaries in NE Iowa appear to have peaked and levels are
receding there. With precipitation moving out this afternoon,
rivers should begin to crest and then begin to fall tonight into
tomorrow morning.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Storm Warning until 6 PM CST this evening for WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...JAR
AVIATION...Boyne
HYDROLOGY...JAR
Area Forecast Discussion
National Weather Service Binghamton NY
937 PM EST Mon Feb 27 2023
.SYNOPSIS...
Winter storm will impact the region this evening through
Tuesday, with accumulating snow and a light wintry mix. High
pressure then builds into the region Tuesday night into
Wednesday morning with dry weather returning. Another winter
storm will impact the region toward the end of the week.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
With the late evening update temperatures were adjusted in
several spots. Also, radar is showing some sleet trying to
advance further northwest into the Finger Lakes and the Southern
Tier. Modeled QPF remains rather steady, so no major changes
with snowfall totals. Although it may take till sometime Tuesday
morning for these values to be realized.
Only minor updates with the early evening update to the ongoing
forecast mainly to account for wetbulbing at snow onset. Some
mixing is already occurring in Steuben county with sleet but the
mix line is hard time moving further east. Little change in the
latest RAP/HRRR guidance.
315 PM update...
Looking at the national mosaic radar display, precipitation from
this incoming low pressure system is over western Pennsylvania and
New York. Tracking this band of precipitation, it will move in
earlier than expected. Incorporating the NAMNest and HRRR helped
speed up the timing of the onset of this precipitation. While this
precipitation is falling as rain further east, conditions are quite
dry here. This rain will evaporate before reaching the ground but
should help cool conditions, enough for snow to begin this evening.
Strong forcing and plenty of moisture accompanies this system.
Moderate to heavy snowfall is possible this evening and into the
early overnight hours. Snowfall rates will approach 1.5"/hr,
especially along and east of I-81. With these higher snowfall rates,
most of the expected snowfall will occur through the early overnight
hours. Late this evening, a shallow, elevated warm nose develops
west of I-81, which supports a wintry mix of snow, sleet, and
freezing drizzle. After midnight, snow becomes lighter. Model
soundings unzip from the top Tuesday morning. As a result the DGZ
dries out and as the snow tapers off, drizzle and freezing drizzle
become more likely. A light glaze of ice cannot be ruled out, but
this will be on top of already fallen snow.
Southeasterly winds will become gusty this evening. Blowing snow
will lead to reduced visibilities and hazardous driving conditions.
With the initial snow being drier, drifting in open areas would also
be possible. While temperatures will fall into the mid 20s to low
30s tonight, wind chills will fall into the teens.
Generally, snowfall totals were not changed too much from the
previous forecast. There was more confidence with higher snowfall
totals in Oneida, Madison, and Chenango Counties, so the Advisory
was upgraded to a Warning there. Oneida had previously met the
criteria while Madison and Chenango have low end warning amounts.
Totals were derived from WPC and NBM QPF and NBM SLRs. As the
primary low splits from the secondary coastal low that develops
early Tuesday morning, moisture decreases over the Southern Tier, so
less snowfall is expected in the eastern portions of the Southern
Tier, despite some higher snowfall totals to the north and south of
this region. A light glaze of ice will also be possible across the
region due to the wintery mix tonight and freezing drizzle on the
backside of this system.
Wintry precipitation begins to taper off from the southwest
beginning in the late morning hours as high pressure begins to build
into the region. This system completely moves out by the end of the
afternoon. Tuesday night will be dry with skies clearing.
Temperatures Tuesday will be in the upper 30s to low 40s for areas
that will be precip-free in the afternoon. Elsewhere, temps will
only climb into the mid 30s. Overnight lows will be in the upper
teens to mid 20s.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
2 PM Update...
High pressure will be over the region Wednesday morning, but it
quickly slides to our east by early Wednesday afternoon. This
allows for warm southerly flow to push high temperatures into
the mid to upper 40s. Isentropic lift will generate scattered light
rain showers along a warm front across Central NY during the
afternoon and evening. Another wave will push through Wednesday
night into early Thursday morning and spread more showers across
the area.
Thursday will be cooler as NW flow starts pushing colder air
behind an exiting cold front Thursday afternoon and Thursday
night. Highs will top out in the upper 30s to low 40s across
Central NY and further south in the Twin Tiers and into the
Poconos highs will be in the mid to upper 40s. However, the
coldest air doesn`t arrive until late Thursday night into Friday
morning, as overnight lows dip into the teens across the north
and mid to upper 20s in NE PA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Confidence continues to increase that a winter storm will
impact the region the end of the work week and into the upcoming
weekend. Forecast models still have some differences on the
track of the system, with the 12Z guidance now favoring a more
westerly track now. For our region, this would allow for a
warmer air push, as has been the story most of this winter. So
an all snow scenario looks more unlikely with this update, but
still not out of the question. The energy that will eventually
become this storm is still out in the Pacific Ocean and will not
come on shore until tomorrow. Once upper air observations can
sample it, this should help the models come into better
agreement with the forecast solution. For now, have stuck close
to the NBM solution for PoPs and temperatures and also have kept
precipitation types as just rain and snow at this time, due to
the uncertainty. It is very possible that this system will bring
a mixed bag of precipitation to the air, similar to the last
several systems.
Another feature that needs to be monitored is the development
of a high pressure system over eastern Canada, which would feed
cold air into the Northeast US as well as keep the low tracking
through the Mid-Atlantic. Current runs have a weaker high
pressure system, allowing the low`s track to pull further west,
which would favor another mixed precipitation event for most of
the region except for the far northern forecast area.
As the system exits on Saturday, CAA advection on NW flow will
push into the region with the chance for some lake effect snow
showers on Saturday. High pressure/ridging returns on Sunday and
should persist into next week.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A winter storm will bring restrictions across all terminals
through the TAF period.
Snow has moved in from the SW, dropping ELM/BGM/ITH to IFR
with AVP bouncing between IFR and MVFR as showers move overhead.
RME and SYR will see snow fall begin within the next hour or so
and thus conditions fall to IFR. IFR to Below Alternate Mins
are expected to last through the overnight hours and into the
morning as heavy snow will transition to a wintry mix across
these terminals. ELM and AVP will transition around midnight,
while BGM and ITH will see the wintry mix move in around
sunrise. SYR and RME will keep snow through the period.
Conditions are expected to gradually improve through the
morning as the system moves eastward with an Fuel Alt cloud deck
sticking around through the afternoon.
Winds will be gusty tonight, out of the SSE between 20-30kts,
which will cause blowing snow and help keep visibilities in the
IFR to Below Fuel Alt range.
Outlook...
Tuesday night...Lingering restrictions, but gradually improving
conditions to MVFR or VFR.
Wednesday...Mainly VFR.
Wednesday Night through Thursday...Some restrictions with rain
showers.
Friday through Saturday...Restrictions likely with snow and
wintry mix.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Winter Storm Warning until 7 PM EST Tuesday for PAZ040-048-072.
Winter Weather Advisory until 1 PM EST Tuesday for PAZ038-043-
044-047.
Winter Weather Advisory until 7 PM EST Tuesday for PAZ039.
NY...Winter Storm Warning until 7 PM EST Tuesday for NYZ009-036-037-
045-046-057-062.
Winter Weather Advisory until 1 PM EST Tuesday for NYZ015>017-
022>025-055.
Winter Weather Advisory until 7 PM EST Tuesday for NYZ018-044-
056.
&&
$$
SYNOPSIS...BJT
NEAR TERM...BTL/BJT/MWG
SHORT TERM...MPK
LONG TERM...JTC/MPK
AVIATION...JTC
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
1002 PM CST Mon Feb 27 2023
.UPDATE...
Issued at 938 PM CST Mon Feb 27 2023
No big changes to the going forecast we did make some minor
changes to pops Tuesday morning and winds Tuesday through Tuesday
night.
Currently, High pressure is situated over western ND and a weak
dry cold front is dropping southeast through the state. The
surface high will track east into central and eastern ND by 12 UTC
Tuesday. As the surface high moves east there will be a period of
light winds over a good portion of central ND. Skies are already
mostly clear so a period of good radiational cooling can be
expected. Low level moisture is quite shallow but NBM probs have
increased a bit from earlier this evening. Will add a bit of
patchy fog over central ND late tonight into Tuesday morning.
Latest short term models are a little slower to lift precipitation
into ND Tuesday. We blended some of the latest short term pop
guidance with the our current pops Tuesday morning to slow the
arrival down just a bit. Winds were also blended with some of the
latest short term guidance Tuesday and Tuesday night, toning down
winds just a little. Overall, minimal changes were needed this
evening.
UPDATE Issued at 544 PM CST Mon Feb 27 2023
Mostly sunny skies across western and central ND late this Monday
afternoon. A weak frontal boundary will drop southeast through
the forecast area this evening with building high pressure from
the west. winds should diminish fairly quickly over the west and
south central, but may hold up a bit over the north central into
the James River Valley. Overall, no significant changes to the
going forecast. Made some minor adjustments to sky cover this
evening. No changes to the current headlines and updated text
products will be transmitted shortly.
&&
.SHORT TERM...(Tonight)
Issued at 249 PM CST Mon Feb 27 2023
Quiet weather this evening with some fog possible overnight
highlights the short term period.
The upper levels this afternoon were characterized by active flow
across the northern United States and into Canada, with a shortwave
crossing nearly zonal flow over Saskatchewan and Manitoba, while a
shortwave digs through a deeper trough over the west coast into
northern California. Today`s southern Canadian wave has brought
gusty winds across the Northern Plains with isolated gusts up to
around 40 mph observed this afternoon. Behind a front that had
passed earlier, mostly clear skies are observed with mild
high temperatures.
Tonight temperatures will dip to near zero across the north and to
10 above across the south as the cold surface high crosses the
region. With the light winds some fog may develop, however with dry
air associated with the surface high the coverage is uncertain and
high-res guidance is in disagreement about when to develop any fog.
Will leave this messaging for the future shifts when further details
emerge.
.LONG TERM...(Tuesday through Monday)
Issued at 249 PM CST Mon Feb 27 2023
Snow and blowing snow Tuesday and Wednesday, especially across
much of southern North Dakota, highlights the long term period.
The aforementioned west coast trough will continue to dig through
mid-week with an upstream upper level jet intensifying the
trough. A speed max is expected to eject through this trough
Tuesday and Wednesday, deepening a mid-level low over the Dakotas.
The combination of moderate isentropic lift and lower level
frontogenesis should develop areas of moderate to possibly heavy
snow across southern North Dakota. This low amplitude open wave
shortwave lends itself to uncertainty in north-south placement of
the possible frontogenetic snow banding necessary for reaching 6
or more of snow. Current probabilities have highest values in the
south central through southeast, along and south of the I-94
corridor. However these probabilities, topping out at 50-60
percent, leave a lot of room for shifting of what may be a
spatially narrow band even with lead time crossing the 24 hour
mark. With this in mind, a Winter Weather Advisory has been issued
for snow and blowing snow, with heavy emphasis on the fact that
heavier snow accumulations are possible for some areas. The
location of these heavy rates may not fully present themselves
until this system really develops on Tuesday, which may
necessitate a shorter lead time Winter Storm Warning decision as
the snow bands develop. Additionally, a tightening pressure
gradient may combine with the heavy snowfall rates to produce
significantly reduced visibilities, depending on the overlap of
these rates and winds to around 45 mph. Those with travel plans
should stay up to date with the forecast and potential warnings as
conditions may deteriorate even worse than currently forecast if
these multiple factors line up.
Colder temperatures will follow this system as a surface high
quickly builds in, leading to forecast highs on Wednesday from
around 10 north central to near 20 southwest. Milder air moves back
in starting Thursday as modest ridging takes place over the region.
Starting later this weekend into next week, there is moderate
agreement in the 500mb ensembles developing western CONUS troughing
with southwest flow over the Northern Plains. This brings
precipitation chances back into the forecast, with slight chance
PoPs in the day 7 period at this time.&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1152 AM CST Mon Feb 27 2023
VFR expected through the day today at all terminals. Winds up to
30 kts continue this afternoon and then taper off this evening.
Fog may develop across areas of the north after 08Z, but with high
uncertainty regarding impacts at KXWA-KMOT. Left fog out of TAFs
with this issuance but this may need to be added if things change.
Snow with low ceilings is expected to spread from the south during
the day Tuesday, but impacts will likely wait at KDIK-KBIS until
around or after 18Z.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 938 PM CST Mon Feb 27 2023
VFR conditions early, patchy fog possible late tonight into Tuesday
morning, snow moves in from the south impacting southern TAF
sites after 18 UTC.
VFR conditions are expected through this evening and into the
early overnight hours at all terminals. Latest HRRR and to a
greater extent RAP continues indicate fog may develop across the
area around or after 08 UTC. NBM probabilities of vsbys <3mi and
cigs <1kft are not as aggressive and HRRR/RAP but have indicated
some uptick since early evening. Given the consistency of the
RAP/HRRR and increase in NBM probabilities we did mention patchy
fog in the gridded forecast but at this time vsby/cig reductions
at any one TAF site remain uncertain. Will hold off on adding fog
at this time, but fog may still need to be added if things
change. Snow is expected to spread from the south during the day
Tuesday, but MVFR-IFR cigs and vsbys in snow should hold off until
around or after 20 UTC.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from noon CST /11 AM MST/ Tuesday to
noon CST /11 AM MST/ Wednesday for NDZ033>037-040>048-050-051.
&&
$$
UPDATE...TWH
SHORT TERM...AE
LONG TERM...AE
AVIATION...TWH
Area Forecast Discussion
National Weather Service Billings MT
840 PM MST Mon Feb 27 2023
.UPDATE...
Satellite imagery shows a period of clearing skies over the west
half of our cwa, in an area of weak shortwave ridging ahead of
moist Pacific SW flow which is already spreading high clouds to
south central MT. This area of clearing will move west to east
through our cwa over the next several hours, while the west sees
increasing clouds. The next few hours may provide an opportunity
for viewing the northern lights.
Otherwise, a quiet weather night as we await the Pacific moisture,
which should spread some mountain snow to our west beginning
overnight. Fog is possible in our far southeast (mainly Carter
county) late tonight...a result of a shift to easterly winds and
some boundary layer moistening from snow melt earlier today. HRRR
is consistently showing visibility reductions in this area from
roughly 10-16z tomorrow morning. Have added mention of patchy fog
accordingly, and have adjusted sky cover per trends. Otherwise,
forecast is in good shape.
JKL
&&
.DISCUSSION...
Tonight through Tuesday night...
The main highlight in the short-term is the shortwave moving
through tomorrow and tomorrow night. As it does, there will be a
surface low that develops over northeast Wyoming and northwest
South Dakota. This will lead to an inverted surface trough and
upslope flow into the far southeast. Currently have a a couple of
inches across mainly Fallon County, with the northern part of
Carter County, north of Ekalaka. The best axis for precipitation
is from Baker southeast toward Buffalo, SD. For much of the rest
of the area, cannot rule out some light snow accumulations, but
amounts will be less than an inch. Winds will increase some, the
most across near the surface low, but overall should be gusting
in the 20s and 30s. Temperatures will remain a little below
normal.
Through the rest of the day today, wave that brought snow
overnight last night will push out of the area. There will still
be some light snow accumulations in mainly Carter County, but will
generally just be a dusting. With the instability, the snow could
be briefly heavy. ANother weak wave will move through, that could
produce a little more light snow, but anything will be generally a
dusting. Reimer
Wednesday through Monday...
Wednesday will be the coldest day of this work week with high
temperatures generally in the upper 20s across the region. Any
remaining snow showers out east will move out of the region
through the day. Temperatures will then warm Thursday back into
the mid to upper 30s across the region as a shortwave ridge moves
through. Thursday will also see increase winds along the western
foothills, as our local wind guidance currently shows a 65% chance
for 50 mph and 40% chance for 58 mph winds in Livingston. By
Friday, windy conditions will move through the lower elevations
with a passing shortwave aloft. This disturbance will bring snow
chances (50-70% chance for snow) back to the mountains during the
day.
All eyes then turn to Sunday as a pattern change is expected to
begin with more widespread snow to start next week and colder
than normal temperatures. Right now, most of our region has a
40-50% chance for accumulating snow Sunday through Monday. High
temperatures also look like they will be in the low 20s across
much of the region through the week. While that may not seem that
cold, our normal highs for Monday (3/6) across the region are 46
in Billings, 45 in Sheridan and Livingston, and 42 in Baker.
Arends
&&
.AVIATION...
VFR conditions will generally prevail through 12z Tuesday. There
could be some localized MVFR after 12z Tuesday around KLVM, with
some snow showers. Patchy fog is expected after 09z Tuesday over
southeast MT, near and east of K4BQ, and possibly near KSHR. Any
fog would dissipate by 19z Tuesday. In addition, after 12z Tuesday expect
conditions to be decreasing mainly around KBHK southeast into
South Dakota. Expect mountain obscuration to be prevalent.
Reimer/RMS
&&
.PRELIMINARY POINT TEMP/POPS...
Tue Wed Thu Fri Sat Sun Mon
-----------------------------------------------------------
BIL 021/041 019/030 017/039 026/039 021/040 023/039 022/031
02/J 22/S 00/B 11/N 10/B 13/S 54/S
LVM 019/035 014/029 012/037 021/031 015/035 019/034 017/030
14/J 22/S 00/N 22/S 11/B 24/S 44/S
HDN 014/039 014/028 009/039 021/039 013/039 015/037 017/031
02/J 31/E 10/B 12/S 10/B 12/S 55/S
MLS 014/033 015/023 011/037 024/036 017/037 016/035 017/028
05/S 41/E 00/B 01/B 00/U 01/B 33/S
4BQ 019/038 017/028 016/038 025/038 018/039 020/041 021/033
13/J 31/E 10/B 11/B 00/U 01/B 33/S
BHK 011/031 012/021 009/035 020/034 013/034 015/033 014/026
08/S 81/E 10/B 00/N 00/U 01/B 23/S
SHR 013/037 009/027 009/036 017/033 009/033 013/035 013/029
12/J 22/S 20/U 13/S 20/B 01/B 45/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect from 5 AM Tuesday to 5 AM
MST Wednesday FOR ZONES 33-37.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Corpus Christi TX
940 PM CST Mon Feb 27 2023
...New UPDATE...
.UPDATE...
Issued at 935 PM CST Mon Feb 27 2023
Satellite imagery shows, and coastal visibility sensors confirm,
dense fog spreading inland from the near shore waters into the
coastal regions of the Middle Texas coast. Issued a Dense Fog
Advisory for the bays and near shore waters along with the coastal
areas until 16Z Tuesday. High surface moisture has moved inland
with the sea breeze as dewpoint temperatures are in the mid 60s
from HBV to BEA. HRRR and SREF models show high likelihood the
dense fog will move inland into the coastal plains during the
overnight hours. Dense Fog Advisory is in effect for the inland
coastal plains from 06-15Z Tuesday.
&&
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 350 PM CST Mon Feb 27 2023
Key Messages:
- Patchy to areas of fog/dense fog tonight
- Very warm temperatures on Tuesday
A Pacific front has made it`s way across South Texas today, with
the boundary currently reaching the coast and extending from a
line beginning just to the south of Port Lavaca running westward to
Rockport to Kingsville. Dry conditions have developed in it`s
wake, with RH values in the 50s right along it, decreasing to the
teens over portions of the western Brush Country. Clearing skies
have also followed. This boundary will be briefly stalling along
the coast this afternoon, before retreating northward this evening
and overnight as a warm front. Current north to northeasterly
winds are progged to become onshore overnight as the front lifts
back up. This will in turn allow for moisture to increase across
the area. Tonight, the primary concern will be the possibility for
patchy to areas of fog to develop, due to the combination of light
southerly winds, enough low-level moisture and dry mid-levels.
Some areas, mainly across the inland Coastal Plains, could
experience dense fog reducing visibilities to less than a 1/4 of a
mile at times. Lows tonight will range from the mid 50s across
the northern CWA to the mid 60s along the coast.
Tuesday will be even warmer with highs potentially reaching into
the mid 90s over portions of the Brush Country and Rio Grande
Plains. ECMWF and GFS ensemble members indicate an 80-90%
probability of these areas experiencing high temperatures above
90s degrees. Other than that, expecting cloudy to mostly cloudy
skies in the morning, becoming partly cloudy by the afternoon
under a moderate southerly breeze. Tuesday night will be warmer
than tonight, with lows in the mid to upper 60s areawide. A
developing 35-40 knots LLJ may limit the fog potential tomorrow
night.
&&
.LONG TERM...
(Wednesday through next Sunday)
Issued at 350 PM CST Mon Feb 27 2023
- Hot temperatures mid-week
- Strong Cold Front Thursday evening
Temperatures will continue to heat up through the middle of the
week with very dry air in the low levels and 850 temps approaching
25C. We`re starting to wonder if when the calendar flips from
February it`s just going to May? We`ll approach record highs on
Wednesday, and likely break some on Wednesday...Laredo could be by
5 degrees or more. NBM probabilities currently show a 96 percent
chance of topping 100 along the Rio Grande. While not as high,
ECMWF ensembles are not far off this and GEFS is only marginally
lower...still around 60%. Have 90s forecast for a good portion of
the area, with 80s along the immediate coast and toward the
Victoria Crossroads.
Records: Wed Thur
Corpus Christi 92 98
Victoria 89 95
Laredo 100 96
After the hear on Thursday, a fairly robust cold front will move
through as a closed low in the mid-levels dives into North Texas.
Frontal timing has been fairly consistent with timing mainly
Thursday evening. An isolated shower or thunderstorm is possible
in the northern Coastal Bend, but most of the moisture will remain
north of the area. Strong winds develop behind the front and will
likely lead to at least an elevated, possibly critical fire
weather risk in the overnight period as the air dries very
quickly. Overnight lows into the 50s and maybe even some 40s. High
temperatures drop to near or slightly below normal for Friday
with highs mainly in the 70s. A general warming trend is expected
this weekend, but a weak reinforcing ridge may settle in before
onshore flow returns late Sunday.
&&
.AVIATION...
(00Z TAFS)
Issued at 600 PM CST Mon Feb 27 2023
Boundary stalled along the coast this afternoon and is drifting
inland with a weak sea breeze. Low level moisture will gradually
move inland this evening. Expecting sea fog developing over the
near shore waters this evening will move inland with IFR vsbys
affecting CRP/VCT by 04-05Z. HRRR model and SREF probabilities for
LIFR increase after midnight for the coastal plains with dense
fog/LIFR conditions likely east of a BKS-PEZ line through 15Z
Tuesday. SREF and HRRR show the stratus and low clouds/fog moving
westward through the Brush Country with a higher likelihood of
reaching COT by 09Z. Will show TEMPO for possible IFR ceilings/MVFR
vsbys reaching LRD around daybreak. Conditions will improve by
mid morning for the Brush Country and late morning for the coastal
plains. VFR conditions will occur in the afternoon with light to
moderate southerly winds.
&&
.MARINE...
Issued at 350 PM CST Mon Feb 27 2023
A generally weak to moderate onshore flow can be expected across
the coastal waters tonight. Weak warm moist air will likely lead
to sea fog tonight into Tuesday morning. Winds will increase to
more moderate levels Tuesday night, with exercise caution
conditions possible. Onshore flow will increase to strong levels
Wednesday and Thursday, with a Small Craft Advisory possible. A
cold front will push across the waters Thursday night/Friday
morning. Offshore flow will strengthen to 20 to 30 knots behind
the front with occasional gusts to gale force possible. Winds will
weaken and shift more northeasterly through the weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 64 86 68 87 / 0 0 0 0
Victoria 59 84 68 84 / 0 0 0 0
Laredo 64 94 68 97 / 0 0 0 0
Alice 62 89 67 93 / 0 0 0 0
Rockport 66 79 68 79 / 0 0 0 0
Cotulla 58 95 67 94 / 0 0 0 0
Kingsville 64 87 67 93 / 0 0 0 0
Navy Corpus 66 83 68 77 / 0 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Dense Fog Advisory until 9 AM CST Tuesday for TXZ231>234-241>244-
246-247.
Dense Fog Advisory until 10 AM CST Tuesday for TXZ245-342>347-
442-443-447.
GM...Dense Fog Advisory until 10 AM CST Tuesday for GMZ231-232-236-
237-250-255.
&&
$$
SHORT TERM...ANM
LONG TERM....PH
AVIATION...TMT/89
Area Forecast Discussion
National Weather Service Des Moines IA
544 PM CST Mon Feb 27 2023
...Updated for the 00z Aviation Discussion...
.DISCUSSION.../Tonight through Monday/
Issued at 158 PM CST Mon Feb 27 2023
Key Messages:
-- Breezy winds subsiding into tonight
-- Near to above normal temperatures into this weekend
-- Light rain or snow chances later Tuesday afternoon into early
Wednesday over northern Iowa
-- Another precipitation window possible late this week
Details: Visible satellite imagery shows clouds over much of Iowa
with a clearing line nearing the Loess Hills of western Iowa as
the surface low and trough lift northeast and begin to move over
Lake Michigan. As the low moved away, the rain came to an end with
gusty winds following behind in the subsidence. Fog concerns for
tonight are low at this point despite the rainfall and winds that
will lessen, particularly after midnight over western Iowa.
However, drier air will be arriving as shown by forecast soundings
with no surface saturation and far from saturation in the low
levels. So, widespread dense fog is unlikely with possibly light
fog in a few sheltered locations.
For this week into this weekend, temperatures will be near if not
above normal for late February/early March. The flow over our region
becomes more zonal and fast tonight into the middle of this week
with a shortwave trough tracking through the area Tuesday
afternoon into Tuesday night. This will bring a fair amount of QG
convergence/forcing to the region, but moisture return is
marginal. Deep layer saturation will only last for a short period
of time after the initial low level dry air is overcome.
Therefore, only light precipitation is expected over the northern
half of Iowa with snow the main type near the Minnesota border
with little if any accumulation and rain elsewhere over the north
half. As the light precipitation ends toward Wednesday morning
and the mid-levels dry, there will be lingering low level
saturation. The 12z NAM is deeper in its saturation depth and
would suggest drizzle or freezing drizzle depending on time and
air temperature whereas the 15z RAP and 12z HRRR would be dry
with a shallow saturated layer if any. This will be something to
watch since if it came to fruition Wednesday morning, may impact
the morning commute.
Attention then focuses on a strong shortwave trough that cycles
through the Deep South into the Ohio Valley late this week into
this weekend. Gulf of Mexico moisture will surge poleward into the
middle Mississippi River Valley and perhaps into portions of Iowa
Thursday night into Friday. As mentioned by the midshift, the 00z
deterministic and now the 12z deterministic minus the GFS give
only a glancing blow of precipitation to southern Iowa. However,
ensemble members have quite the variability in their QPF placement
in this timeframe with the GEFS having the most members farther
north with a few in each of the CMC and ECMWF also similarly
farther north. With the latest available cluster analysis showing
three clusters or solutions that are evenly weighted, will not
deviate from the going forecast. Winds will likely increase in
this period, particularly over southeastern Iowa, given the
closer proximity to the eventual path of a surface low pressure.
&&
.AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/
Issued at 542 PM CST Mon Feb 27 2023
IFR to MVFR stratus will gradually clear from west to east this
evening and overnight. VFR conditions will follow through most of
Tuesday. A few rain/snow showers may occur over northern sites
during the afternoon. Any cigs should remain mostly VFR despite
any precipitation. Breezy to gusty norhtwest wind this evening
will diminish overnight then become east/southeast on Tuesday.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Ansorge
AVIATION...Donavon
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
505 PM CST Mon Feb 27 2023
...AVIATION UPDATE...
.DISCUSSION...(This evening through Monday)
Issued at 221 PM CST Mon Feb 27 2023
Key Messages:
*Breezy winds today calming down this evening
*Small chance for some light snow tomorrow morning
*Next system comes through on Thursday bringing some colder temps
and a chance for some snow
Overall a fairly quiet and straight forward forecast. Transitioning
to quasi zonal flow aloft today as the upper level trof departs to
the east. Breezy to borderline windy northwest winds this morning
have continued this afternoon but are starting to come down and will
continue to do so this evening. Winds will then go light and
variable overnight as they shift around to the southeast by tomorrow
midday. Highs are still on track to be generally in the 50s today.
A quick moving shortwave aloft will pass through the area tomorrow.
Thanks to its lift and some WAA, we could see some light snow fall
northeast of the Tri-Cities tomorrow morning. Though not every model
is latching on to this possibility as there could be too much dry
air at the surface, so confidence is not the highest at the moment.
Tomorrow will also be slightly cooler with lighter winds and highs
near 50. Wednesday will be dry and slightly cooler still with highs
in the 40s and 50s.
Our next system comes on Thursday as potential closed low aloft
moves through the Southern Plains. The bulk of the precip will be to
our south with Kansas standing the best chance at seeing some snow
accumulations. Thursday will also be the coldest day of the week
with highs only in the 30s. Snow will be the main precip type,
though some rain may be mixed in there down in Kansas areas later
in the day on Thursday.
Dry conditions return by Friday onward. Temperatures climb back up
into the 40s on Friday and Saturday with 50s and 60s again by Sunday.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday)
Issued at 445 PM CST Mon Feb 27 2023
The winds will taper off this evening and look to go VRB
overnight. The pickup out of the SE tomorrow morning and will
become southwesterly near the end of the TAF as a cold front will
be moving through the area. Debated about adding some BR, but a
few of the models are showing some moisture at the SFC and with
the recent rains adding to the soil moisture I decided to throw
in a hint of BR. the HRRR and RAP show some light BR, but the NAM
brings it in heavy, so decided at least a mention with the light
winds overnight.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Shawkey
AVIATION...Beda
Area Forecast Discussion
National Weather Service Goodland KS
650 PM MST Mon Feb 27 2023
.UPDATE...
Issued at 650 PM MST Mon Feb 27 2023
A Red Flag Warning for Critical fire weather conditions has been
issued for Cheyenne county Colorado, Wallace, Greeley and Wichita
counties in Kansas Tuesday afternoon from 1 PM MST (2 PM CST)
through 5 PM MST (6 PM CST). This was based on the better
performing guidance collected over the last two years when Red
Flag Warnings were in effect, close to the previous forecast and
in line with surrounding offices.
Also monitoring the potential for some blowing dust along
Interstate 70 from Flagler to about Colby and Oakley in the
17z-20z timeframe Tuesday. This is using the GFS model 0.5-1km
winds over 44kts and 0-2km lapse rates around 10C/km. The GFS has
a near perfect/perfect track record of blowing dust when these two
parameters are met. This corridor is also where surface wind gusts
are the highest in that timeframe. Will await the 00z GFS to see
if it supports the 18z run before inserting blowing dust into the
forecast.
UPDATE Issued at 520 PM MST Mon Feb 27 2023
A stationary frontal boundary is forecast to set up from roughly
Wray to Goodland and Russell Springs a few hours before and after
sunrise Tuesday morning. NAM/GFS boundary layer rh forecasts show
saturation while the HRRR shows some stratus. Visibility forecasts
are advertising some patchy fog along the front. As a result,
patchy fog was manually added to the forecast in these areas.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 255 PM MST Mon Feb 27 2023
Overview: Westerly flow aloft (over the Rockies and adjacent High
Plains) will back to SW in this period, as an upper level low..
presently situated along the northern coast of British Columbia..
digs southward through the PAC NW (Tue-Tue night) into southern
CA/NV (Wed).
Through Tonight: Low-level flow will shift to the E and veer to
the SE-SSE late tonight, on the eastern periphery of a developing
lee trough/cyclone in eastern CO -- presumably associated with a
SW-NE oriented shear axis approaching from the west. Aside from
mid-upper level cloud cover that may develop over portions of the
area (mainly north of I-70) this evening into tonight, expect
otherwise clear skies.. with lows ranging from the lower to upper
20s.
Tuesday: The aforementioned lee surface trough/cyclone --
manifesting as a WNW-ESE oriented trough at the 850 mb level --
will progress eastward across the Tri-State area during the late
morning and early afternoon. In spite of a modest MSLP-H85 height
gradient, deep (7,000-10,000 ft AGL) vertical mixing in the wake
of the H85 trough will foster the development of strong westerly
winds Tue afternoon. Forecast soundings via the GFS indicate at
least ~30-35 knot flow will be present throughout the mixed layer
-- perhaps as much as 40-45 knots in portions of the area (mainly
in eastern CO and areas south of I-70 in northwest KS). With the
above in mind, expect sustained westerly winds generally ranging
from 25-35 mph with gusts up to 50 mph, except in areas situated
south of I-70 in eastern CO and western KS -- where sustained
winds may reach 30-45 mph and occasional gusts up to 60 mph are
possible. Expect highs ranging from the upper 40s (northeast CO
where some snowpack persists) to upper 50s and lower 60s
elsewhere.
Tuesday night: Winds will shift to the NW around sunset Tue
evening.. as modest (~1010 mb) high pressure builds into the
region from the W and NW.. becoming light and variable during the
late evening and overnight. Expect colder lows ranging from the
upper teens to mid-upper 20s.. coldest in eastern CO.
Wednesday: Below average confidence, especially w/regard to
temperatures. A relatively robust/pronounced lee cyclone will
develop in eastern CO on Wed.. in response to height falls as an
upper level low digs southward through the Intermountain West and
upper level flow backs to the SSW atop the Rockies. Low-level
(SFC-H85) height/wind/thermal fields will highly depend upon the
precise evolution of the lee cyclone. A temperature gradient will
likely exist over the region.. warmer in the southwest, colder in
the northeast. At this time, expect increasing cloud cover
throughout the day.. with highs ranging from the upper 30s to
lower 50s. Drizzle and/or fog cannot be ruled out over portions of
the area.. mainly in northeast CO and adjacent border counties of
KS/NE.
.LONG TERM...(Wednesday night through Monday)
Issued at 104 PM MST Mon Feb 27 2023
At 00Z Thursday, flow aloft is out of the southwest as an upper
level low center is situated over southern California and Nevada.
The low continues an east-southeastward track up through Thursday
night when it turns northeastward as it crosses the Red River. A
surface low center traverses through New Mexico, the Texas
Panhandle, to the DFW/OKC area throughout the day on Thursday. Out
of this system, expect snow chances for the Tri-State Area with
up to a few inches of snow accumulation for southern portions.
Flow shifts northwesterly before backing to the west as a shortwave
trough slides southeast over the Continental Divide Friday
afternoon/evening. We`ll again see a brief chance for some snow for
portions of the Tri-State Area Friday night as the shortwave moves
through the area. Upper-level ridging builds into the area over the
weekend and flow becomes westerly to southwesterly by the start of
the week. In this same timeframe, another upper low center sets up
off the coast of the Pacific Northwest.
Snow chances for the area from Wednesday evening through the day
Thursday with accumulations up to a few inches possible, highest
totals with the event currently expected over southern portions of
the area, generally south of I-70. North-northeasterly winds gusting
up to 30-35 mph are also possible. High temperatures only climb into
the 30s on Thursday. Low temperatures Friday morning will be in the
teens to low-20s before warming into the upper-30s to upper-40s.
Another brief chance for light snow across western portions of the
area Friday night. Similar temperatures on Saturday compared to
Friday. Warmer temperatures expected for the start of the week
with highs on Sunday in the 50s to low-60s and on Monday in the
mid-40s to upper-50s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 255 PM MST Mon Feb 27 2023
GLD: VFR conditions will prevail through the TAF period. Breezy
(15-25 knot) NW winds will decrease to 12-17 knots by late
afternoon -- becoming light/variable at or around sunset this
evening. Winds will gradually shift from E to SE overnight..
further veering to the S and increasing to 15-20 knots late Tue
morning. Winds will abruptly shift to the W and strengthen to
25-35 knots late Tue morning (~18Z).. with gusts up to ~40 knots
possible during the afternoon.
MCK: VFR conditions will prevail through the majority of the TAF
period. A period of MVFR ceilings (1500-2500 ft AGL) cannot be
ruled out late Tue morning (12-18Z).. though confidence is low
with regard to whether or not stratus will develop. Breezy (20-30
knot) NW winds will decrease to 15-20 knots by late afternoon --
becoming light/variable around or shortly after sunset this
evening. Winds will gradually shift from E to SE overnight..
further veering to the SSE and increasing to 15-20 knots late Tue
morning. Winds will abruptly shift to the W and strengthen to
20-30 knots early Tue afternoon (~18-20Z Tue).. with gusts up to
~35 knots possible.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Red Flag Warning from noon MST /1 PM CST/ to 5 PM MST /6 PM CST/
Tuesday for KSZ027-041-042.
CO...Red Flag Warning from noon to 5 PM MST Tuesday for COZ254.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...Vincent
LONG TERM...CC
AVIATION...Vincent
Area Forecast Discussion
National Weather Service Green Bay WI
908 PM CST Mon Feb 27 2023
Updated aviation portion for 06Z TAF issuance
and new information added to update section
.UPDATE...
Issued at 901 PM CST Mon Feb 27 2023
Steady snows were tapering off over far northeast WI, so have
allowed the Winter Storm Warning to expire. Patchy light snow and
freezing drizzle will persist for a few more hours before
departing. Have issued a Special Weather Statement to highlight
the potential for wet roads to freeze as temperatures fall
overnight.
UPDATE
Issued at 602 PM CST Mon Feb 27 2023
Have allowed the headlines to expire across NC/C/EC WI. Light snow
or mixed precipitation (EC WI) will taper off in the next couple
hours, with additional accumulations of an inch or less. Moderate
snow continues across far northeast WI, where an additional 1 to 2
inches appears likely through 8 pm or 9 pm. Will let the remaining
Winter Storm Warning in far NE WI continue through the 9 pm
expiration.
Once the snow tapers off, attention will turn to the potential for
wet roads to freeze as temperatures drop overnight. Will likely
issue a Special Weather Statement within the next couple hours.
&&
.SHORT TERM...Tonight and Tuesday
Issued at 257 PM CST Mon Feb 27 2023
Do not plan to make any changes to current headlines based on
current trends and keep current headlines in place to expiration.
As of 2 pm CST, had officially 2.7 inches at WFO GRB before snow
changed back over to light freezing rain. Just a little bit
further north in southern Marinette and Oconto counties roughly 2
to 5 inches with snow still falling there. Roughly along and south
of a line from Kewaunee to GRB to CWA...surface TWs have climbed
to the freezing mark with light rain or freezing rain being
reported generally east of Highway 41 with mixed precipitation
finally changing over to snow to the west as colder air working in
from the west. Expect light liquid precipitation to quickly
change over to snow, with snow expected for most areas for the
evening commute.
Latest IR and low-level WV imagery showing more consolidation in
the deformation cloud shield over the forecast area northwest of
the upper-level circulation moving into southwest lower Michigan.
This is in response to another weak upper-level impulse over
northern Wisconsin that is forecast to phase with the primary
upper-level circulation. CAM guidance seems to generally capture
this interaction with an uptick in low to mid-level vertical
motion accompanying lingering robust frontogenetic forcing for
the rest of this afternoon. Latest RAP soundings now indicate
that the elevated warm layer is collapsing rapidly with just a
shallow surface-based,slightly above freezing warm layer. Radar
trends last hour also indicate that the lower CC values indicative
of mixed precipitation is quickly disappearing with radar returns
now indicating transition back to snow over nearly all of the
forecast area except the far southwest counties. Latest CAMS
indicated that this last burst of light to moderate snow over
eastcentral Wisconsin will persist into the early evening. Expect
to see an additional inch or two over eastcentral sections.
Meanwhile north and west of the Fox Valley, precipitation type has
been mostly snow all day. Expect an additional 2 to 4 inches with
the heaviest amounts across the southern half of Oconto,
Marinette and Door counties where mesoscale forcing has been
strongest. Would not be surprised to see some storm total amounts
reaching 8 or 9 inches before precipitation diminishes by 9 pm
there.
Bottom line...will maintain WWY for EC Wisconsin and the Winter
Storm Warning for central Wisconsin until the 6 pm expiration,
and the Winter Storm Warning for northeast Wisconsin until 9 pm
where the snow will taper off later.
Suite of short-term/CAM model guidance fairly uniform in shifting
strongest forcing and associated precipitation shield east of the
forecast area by 03Z with clouds persisting overnight. As weak
subsidence and drier air work into the area on Tuesday, expect to
see skies to become partly cloudy with daytime highs rebounding
nicely into the upper 30s.
.LONG TERM...Tuesday Night Through Monday
Issued at 257 PM CST Mon Feb 27 2023
A chance for light to moderate snow at the start of the long term
forecast, followed by relatively quiet weather.
Isentropic lift and a mid-level shortwave combine to produce a
decent period of lift Tuesday night into Wednesday morning.
Moisture is lacking at the start, so may take a bit of time to
saturate the column, but models are in overall agreement on most
of the area seeing at least a small amount of precipitation.
Temperatures support nearly all snow, with a little rain possibly
mixing in across the lakeshore or Fox Valley. Models are still
undecided in specific timing and QPF, as this looks like a quick
event. Less confident in QPF/snowfall amounts at this time, with a
dusting to one inch in the current forecast based on the blended
model solution. Although, would not be surprised if some areas
received up to two inches.
Surface high pressure will result in dry weather on Thursday.
Friday looks mainly dry as well, however a system is forecast to
move from the southern Plains to the Ohio River Valley. Right now,
guidance suggests this system will miss the GRB forecast area.
Changes in the track could bring some light precipitation into the
southeast forecast area. Dry weather is also expected this
weekend as another high pressure moves across the Upper Midwest.
Temperatures will be near normal through the work week, and then
warm a bit next weekend early next week.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 901 PM CST Mon Feb 27 2023
Lingering light snow and freezing drizzle will taper off at the
beginning of the TAF period, but MVFR/IFR ceilings will persist
until clearing arrives late tonight/early Tuesday. Expect VFR
conditions for most of Tuesday and Tuesday evening, though
increasing clouds and a chance of light snow or flurries may
arrive at the western TAF sites toward the end of the TAF period.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.........Kieckbusch
SHORT TERM.....ESB
LONG TERM......KLJ
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Wilmington NC
1007 PM EST Mon Feb 27 2023
.SYNOPSIS...
A dry cold front will push through tonight before shifting back
north through the area Wednesday. Another cold front will
approach the area Thursday followed by a more potent frontal
system Friday. Drier and cooler high pressure will then return
for the weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
No major changes with the latest update.
Band of thicker clouds and a few light showers/sprinkles will
skirt mainly northern portions of the forecast area as a
weakening cold front approaches from the west. Strong low-
level jetting though ahead of the front will continue to allow
for breezy conditions much of the night, as well as for
unusually mild temperatures. In fact, the KLTX VAD Wind Profile
is picking up on 45 to 50 kt winds at around 1k feet above the
surface.
On Tuesday, a mild start, plenty of sun, mainly westerly winds,
and lack of strong cold advection will help temps get back well
above normal to near 80 most places, likely shy of record highs
however.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Low amplitude subtropical ridging, extending from the Caribbean,
will dominate the areas weather this period. Some slight
increase in amplitude in the upper ridging Thu in response to
an upper low moving out of the SW States. Generally WSW-W flow
aloft will dominate. Just from this alone means temps will run
above to well above normal. Generally dry thru the period with
occasional bouts of clouds during this period, ie. Tue night
into Wed when an old sfc front returns north. The exception for
not being dry is during Thu, when a cold front drops south and
stalls across or just north of the area...and will be
accompanied with enough moisture for low chance Pops in the form
of showers, no thunder at this time.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Progressive weather features sfc and aloft to dominate Thu
night thru Sat. Subtropical ridging will be in control early on
as it flexes it`s muscle and pushes the stalled front back north
as a warm front by daybreak Fri. At the same time, the upper
low and accompanying sfc counterpart, exits the SW States Thu
night, and progged to track to the lower Great Lakes by late Fri
night. The best dynamics remain with it but it`s wind fields
sfc and aloft become quite expansive. Will definitely be on the
RR of the upper jet with plenty of ie. 7H UVVs. The cold front
reaches western portions of the FA Fri aftn and off the ILM CWA
Coast late Fri night as it slows down due to it becoming more
oriented parallel to the flow aloft. Peak POPs FRi into Fri
night will stay below 50 given moisture profile thru the atm
column somewhat drying out. Will indicate threat for strong to
possibly severe tstorms, or even from just showers if
instability is limited, given model soundings indicating winds
in excess of 50+ kt at 925mb Fri aftn into the early evening.
Sfc winds will peak Fri aftn into the early evening given the
tightened sfc pg and winds just off the deck tapped and brought
down as gusts to 35 to 45 mph. Best shot of possible wind adv
threat will be the coastal counties at this time.
The cold front should be offshore Sat daybreak with some CAA
with temps continuing to run above normal. However, a secondary
surge late Sat aftn and night, will finally bring temps back
down to reality Sat night thru the remainder of the long term
period. Sfc high pressure and NW flow aloft to dominate.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
High confidence in VFR through the 00Z TAF period across SE NC
and NE SC. Main concerns are the gusty SW to W winds and low-
level wind shear later this evening and much of the overnight
before conditions improve by daybreak.
Extended Outlook...Another period of strong southwest winds
appears possible Friday as strong low pressure moves by to the
north. Model blends suggest surface winds 25 knots with gusts
over 40 knots will be possible Friday afternoon.
&&
.MARINE...
Through Tuesday...
Warm front lifts north across the waters this evening. Low
level jet then progged to increase to 45-50kt by 06Z. With
little to no instability offshore these gusts will not make it
to the surface, but occasional marginal gales should, the Gale
Warning itself looking more marginal than it did in previous
model runs. Saw little value in changing headlines with this
package esp since neighbors didn`t either. Flow veers from SW to
W and abates on Tuesday but an SCA will likely be needed after
Gale Warning is lowered for seas if not a continuation of
advisory- level gusts.
Tuesday Night through Saturday...
A relaxed sfc pg to dominate Tue night thru Wed. Wind
directions may be challenging as a weak frontal boundary
returns just north of the area. Seas this short period will
likely be at their lowest when compared to the remaining period.
The sfc pg does slowly tighten south of this boundary Wed night
and more-so by late Thu night. Seas, will respond mainly at 1st
from a 10+ second period NE-E swell then combined with
increasing wind wave. Seas could reach SCA thresholds before
winds late Thu but usually from a lone long period NE swell
direction is difficult. The main active wind and seas day(s)
will come from late Thu night thru Sat morning where a tightened
sfc pg and 925mb 50+ kt winds will result in SSE-SSW winds
easily eclipsing SCA thresholds and likely reaching Gale
conditions. May see double digit seas at 1 point Fri aftn and
persisting well into the evening. High surf adv thresholds for
south facing land configuration a possibility, ie Brunswick and
Horry Counties. Cold front pushes off the coast and just
offshore early Sat, then finally gets kicked well offshore late
Sat. SCA conditions to continue into sat but with winds only
veering to the WSW-W followed with a diminished trend.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...Gale Warning until 4 AM EST Tuesday for AMZ250-252-254-256.
&&
$$
SYNOPSIS...DCH
NEAR TERM...RJB/MBB
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...RJB/MBB
MARINE...DCH/MBB
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
907 PM CST Mon Feb 27 2023
.UPDATE for snowfall forecast late Tuesday into Wednesday...
Issued at 859 PM CST Mon Feb 27 2023
A winter weather advisory has been issued for several counties across
central Minnesota, with chances for snow now near 100 percent. A
band of snow ahead of a shortwave trough will move across the region,
with snowfall amounts ranging from 2 to 5 inches, and locally higher
amounts possible. This band of snow is driven primarily by low level
frontogenesis at the beginning, and get extra forcing later on as
the upper level divergence associated with the shortwave trough
moves across the same region. For that reason, the residence time of
falling snow is several hours, and precipitation and snowfall amounts
have increased based on the 18Z HiRes models and 21Z Rap. The 00Z
HRRR and NAMNest confirm these trends, so have issued a Winter
Weather Advisory. Overall this system will be weakening as it moves
across the region, but areas in west/central Minnesota could see over
6 inches of snow, while areas in eastern Minnesota and western
Wisconsin will have a much less chance of seeing higher amounts.
&&
.DISCUSSION...(This evening through Monday)
Issued at 315 PM CST Mon Feb 27 2023
KEY MESSAGES:
- Another round of snow likely to bring 1-4 inches of accumulation
for Central Minnesota, and 1-2 inches for Western Wisconsin
Tuesday night through Wednesday.
- Quiet conditions for weekend coupled with a warm-up in
temperatures.
- Potential storm system developing early next week.
This Afternoon through Tonight: Light rain and freezing rain is
exiting Minnesota and western Wisconsin early this afternoon. Precip
amounts of a quarter to three quarters of an inch of rain are common
across areas from the Twin Cities south and eastward. Some of that
did accumulate as freezing rain, with Eau Claire reporting just over
a quarter inch of ice and between 0.10"-0.15" of ice across portions
of eastern Minnesota, including the Twin Cities metro. Temperatures
have been a bit slower to climb above freezing than forecast, but
most are finally at or just above freezing as of 1:30pm. This has
helped alleviate any further freezing rain concerns, so went ahead
and cancelled remaining winter headlines. The back edge of the cloud
cover associated with this system is just starting to make its way
into far western Minnesota. Expect clearing to continue overnight
with temperatures falling into the mid teens to low 20s. Winds are
turning more northwesterly and increasing in speed a bit, so
hopefully this will speed up the evaporation of today`s rain and
keep a widespread refreeze from being much of a concern. However,
slick spots will be possible overnight into the morning before
temperatures warm above freezing again by late morning.
Tuesday into Wednesday: After a brief break from precip Tuesday
morning, a shortwave will approach the Dakotas and Minnesota by the
afternoon. PW values won`t be as high as they were today (MPX 12z
had a whopping 0.88"), but there will still be plenty of moisture in
place with forecast sounding PWs around 0.3-0.4". A band of snow
will develop and move from southwest to northeast across the Dakotas
and Minnesota ahead of the associated surface low late Tuesday
afternoon and continue to spread across central Minnesota and
western Wisconsin through Wednesday afternoon. The heaviest snow
looks to occur between midnight and 6am Wednesday, with snowfall
totals of 1-3" expected across the forecast area. While a few of our
far west central Minnesota counties may see closer to 4", the
heaviest snowfall looks to stay over the eastern Dakotas where fgen
will be maximized. Amounts decrease as you head across eastern and
southern Minnesota and western Wisconsin where amounts of a trace up
to an inch are expected. Some hi-res models indicate that snow may
stick around a bit longer into Wednesday, so bumped up PoPs through
the 18z-00z timeframe.
Snow chances will decrease from west to east before sunrise Thursday
as a shortwave continues to proceed away from the region. Skies will
gradually transition from mostly cloudy to partly cloud by the
afternoon. Forecasted highs in the low 20s south and west of the I-
94 corridor near 30 degrees mainly east of I-35. Aloft, upper-level
flow deepens a positively tilted trough pattern over the Rockies that
will begin to fill as it progresses towards the Central U.S. by
Friday morning. At that time, the trough will dig into the Southern
Plains and force upper-level ridging over the Great Lakes region.
As of now, this system looks to track to our southeast thus keeping
our region precipitation free. Friday`s skies will be partly sunny
with temperatures in the upper 20s and low 30s.
The weekend is shaping up to be quiet as upper-level ridging will be
in wake of the aforementioned low Saturday morning. A weak mid-level
shortwave looks to develop behind the ridge which could generate
some additional cloud cover but otherwise we will remain dry. Winds
will shift to southerly and provide some WAA to aid our temperatures
into the low to mid 30s on Saturday with partly sunny skies and mid
to upper 30s on Sunday under partly cloud skies.
Early next week looks to host our next potential for some
precipitation to the area. Overall, guidance indicates a subtle
shortwave to develop late Sunday night into Monday over the Western
U.S. and progress eastward. However, significant timing differences
exist between guidance members. Therefore, decided to stick with the
NBM guidance at 20-30 PoPs for the entire region. The warm air
advection pattern will continue into next week and encourage highs
to reach the upper 30s to low 40s and low temperatures ranging in
the 30s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 521 PM CST Mon Feb 27 2023
A few sites at MVFR to start the period before quickly improving to
VFR across the board as the cloud layer associated with the departing
system push eastwards. CIGS will scatter out with a few high clouds
lingering around for the bulk of the period before we see our next
CIGS moving after 00z tomorrow as light snow begins for the area,
with MVFR/IFR possible beyond the end of the current period. Winds
begin northwesterly at 5-10kts shifting westerly early on, eventually
becoming easterly/northeasterly by late tomorrow.
KMSP...No additional concerns. -SN and MVFR CIGS are possible by the
last few hours of the period, but were omitted for now.
/OUTLOOK FOR KMSP/
WED...MVFR LIKELY, CHC -SN/IFR. Wind NE 10-20G25-30kts.
THU...VFR. Wind NE 5-10kts.
FRI...VFR. Wind ENE 5-10kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Winter Weather Advisory from 5 PM Tuesday to noon CST Wednesday for
Chippewa-Douglas-Kandiyohi-Lac Qui Parle-Pope-Stevens-Swift.
Winter Weather Advisory from 9 PM Tuesday to 3 PM CST Wednesday for
Benton-Isanti-Kanabec-Mille Lacs-Morrison-Sherburne-Stearns-
Todd.
WI...None.
&&
$$
UPDATE...JRB
DISCUSSION...Dye/RMD
AVIATION...TDH
Area Forecast Discussion
National Weather Service San Francisco Bay Area
419 PM PST Mon Feb 27 2023
.SYNOPSIS...A variety of weather hazards continue this afternoon
with on and off moderate rain, high elevation snow, gusty winds,
small hail and isolated thunderstorms. Cold, unsettled weather
conditions persist into midweek before slightly drier and warmer
weather returns for the second half of the week. Unsettled
conditions return for the upcoming weekend.
&&
.DISCUSSION...as of 2:02 PM PST Monday...This morning and
afternoon have been rocking & rolling with a variety of weather
variables. The cold front moved through this morning, but we
continue to have very active weather behind it. Reports from
social media and our partners have included: moderate to heavy
rain downpours, thunderstorms with small hail, gusty winds of 30
to 50 mph, some roadway flooding at lower elevations, icy roads at
higher elevations (ie Mt Hamilton), light snow accumulations as
low as 1500-1700 ft elevation with moderate accumulations above
3000 ft.
Our Winter Weather Advisories remain in effect for mountain areas
above 3000 ft elevation through 4 pm Thursday. Keep in mind that
we could still see light snow down to around 2000 ft and those
reports down to 1500-1700 ft are likely due to the convective
showers pulling down cold air aloft so that we see snow at those
lower elevations. However, the accumulations at those lower levels
should be light and below Advisory criteria.
As we continue throughout today, the slight chance (15-25%) of
thunderstorms persists as showers continue to move across our CWA.
One of the biggest hazards will be driving today. The combination
of rain (light or heavy), snow, hail, and intermittent gusts
during showers means that roads will be slick. The potential for
spinouts and accidents increases in this kind of weather so please
drive slowly or avoid driving during shower activity in your area.
Have been leaning on the HRRR model as it has had better timing
than the hi-res NAM today. The HRRR shows that shower activity
will lessen (not completely disappear, but not as widespread)
between 8 pm tonight to 2 or 3 am Tuesday morning. At that time,
looks like another pulse of showers will move into the North Bay
then spread into the rest of the Bay Area after 4 am. QPF range
for Tues-Wed will be around a third of an inch in lower elevations
up to an inch in higher elevations for North Bay/East Bay/SF
Peninsula while South Bay/Santa Cruz/Central CA will range around
half inch at lower elevations to 2 inches or more in the Big Sur
coastal mountains. The one exception is the southern Salinas
Valley where rain amounts could be less than a third of an inch.
The risk for thunderstorms and small hail remains around 15 to 25
percent on Tuesday, but should be mainly around the Golden Gate,
Delta region in the East Bay and northward. SPC continues to keep
mainly our North Bay in their Convective Outlook for Tuesday.
The low pressure system bringing all this unsettled weather into
Wednesday morning will exit into SoCal and the Great Basin on
Wednesday afternoon. Behind that, a weak ridge builds over NorCal.
That ridging will give us a dry break, but we are expecting fairly
clear nights which means a very cold Wednesday night into early Thursday
morning. Those overnight lows are forecast to dip down into the
upper 20s and low 30s for much of our CWA. Coastal areas,
including SF county, are forecast to stay 35-40 degrees. This will
be very impactful to the unsheltered population or anyone without
power as they try to stay warm during those cold conditions. For
perspective: Santa Rosa and Napa airports have an 85-95% chance
that overnight lows will be at 32 degrees or colder on Thursday
morning. SFO and OAK have a less than 10% chance of 32 or colder.
Livermore and Concord range 65-85% chance while San Jose has a 90%
chance. Salinas and Watsonville have a 50-60% chance of getting to
freezing on Thursday, but Monterey is less than 20%.
Airmass gradually warms after Thursday, but overnight lows will
only recover to the upper 30s for most areas in our CWA. The next
thing on our radar, pun intended, is that another low pressure
system drops southward into NorCal this coming weekend with more
wet weather.
&&
.AVIATION...as of 04:15 PM PST Monday...For the 00Z TAFs. A cold
front has passed through the area, and in its wake, scattered
showers will continue through the evening. Showers are dropping
mainly moderate rainfall with MVFR cigs/vsby. While showers may
diminish in coverage tonight, another round of rain returns in the
early morning hours, towards 12z. Light to moderate rain will
continue through Tuesday with varied VFR/MVFR cigs/vsbys.
Southerly winds will also increase by mid morning ahead of the
next weak front arriving in the evening. Winds will veer to the
southwest in the afternoon and eventually northwest at night.
Winds will be gusty, generally 20-30 kt.
Vicinity of KSFO...Intermittent rain showers around the bay and
breezy to gusty winds, with gusts 20-25 kt. Some clearing observed
on satellite and webcams, but SCT/BKN clouds likely persist
through tonight. Chance showers continue tonight and increase in
coverage by around 10z-12z, continuing through the end of the TAF
period. Another round of gusty S to SW winds Tuesday, likely
remaining below 30 kt.
KSFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Bands of heavy rain continue to pass over
the area, bringing periods of MVFR/IFR. Showers will diminish
tonight, but increase again towards 12z through the end of the TAF
period. VFR/MVFR cigs and vsbys Tuesday.
&&
.MARINE...as of 03:55 PM PST Monday...Spotty chances for rain
continue throughout the waters, with a slight chance for
thunderstorms through today which will produce gale force gusts.
Winds will diminish slightly tonight and through Tuesday, but
remaining breezy. Winds increase again on Wednesday as another
system approaches. Building northwesterly swell of 12 to 16 feet
at 12 to 14 seconds to arrive through this afternoon into Tuesday
morning.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...Winter Weather Advisory...CAZ504-514-515-517-518
GLW...SF Bay until 9 PM
GLW...Mry Bay until 9 PM
GLW...Pt Arena to Pt Reyes 0-10 nm until 9 PM
GLW...Pt Reyes to Pigeon Pt 0-10 nm until 9 PM
GLW...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM
GLW...Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 PM
GLW...Pt Arena to Pigeon Pt 10-60 nm until 9 PM
GLW...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 9 PM
&&
$$
PUBLIC FORECAST: JBB
AVIATION: Lorber
MARINE: Murdock
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Area Forecast Discussion
National Weather Service New York NY
1000 PM EST Mon Feb 27 2023
.SYNOPSIS...
A storm system impacts the area overnight into Tuesday. Behind
the storm, high pressure builds in from the west Tuesday night
into Wednesday morning. A frontal system will then move through
the area Wednesday night into Thursday. Another storm system
will impact the area Friday into Saturday, with high pressure to
follow into early next week.
&&
.NEAR TERM /THROUGH TUESDAY/...
There has been no changes to winter weather headlines.
As anticipated a steadier snow filled in across the area with
numerous reports of accumulations beginning even on some roadways,
especially to the north and west of the NYC metro. Highest
report thus far is 2.5 inches at Monroe in Orange County NY.
Temperatures have also dropped close to freezing along the coast
and a couple degrees below well inland. However, there is a back
edge to this initial shot moving into the NYC metro, NE NJ, and
the Lower Hudson Valley. This dry punch will allow for some
lighter precipitation and perhaps some sleet and/or rain. This
should be short-lived though with the upper trough approaching
from the west. Precipitation is forecast to fill back in 1-2
hours behind this dry slot.
This is somewhat disjointed system with the initial warm
advection followed by the energy with the upper trough.
Temperatures are marginal as well and there remains some
uncertainty with the extent of mixing at the coast. The latter
of which will have an impact on totals. Additionally, latest
CAMs, HRRR and NEST, show this 1-2 punch. So for the time plan
to stay with the current snowfall totals across the region. The
marginal temperatures will restrict the greatest accumulations
inland where warnings are in place, and to to grassy surfaces,
untreated and secondary roadways across LI and NYC metro, where
advisories are in place.
A strong primary low will continue lifting towards upstate NY
from the Ohio Valley, but will weaken and decay overnight as a
secondary low develops off the Delmarva. The secondary low
should then become the dominant low on Tuesday as it shifts
south and east of Long Island.
After 06z, guidance has continued to hint at some warm air
aloft (700-800 mb) trying to move through portions of the NYC
metro and southern Long Island.
One of the biggest uncertainties with this event is how long
this warmer air aloft will last and how far north and east it
will reach. However, there are several high-resolution models
that keep the warm advection at bay. There is a chance at some
loss of ice nucleation for a time overnight as well, so there
may be some sleet even if the temperatures aloft stay below
freezing. Given the larger pattern and strong warm advection
aloft, think some warming aloft will occur, changing the snow to
a mixture of sleet and snow near the coast. The other factor to
consider is the easterly flow and marginal surface
temperatures. Temperatures over Long Island and NYC metro may
never fall below freezing, and could even stay around 33-34
degrees much of the night. Some locations closest to the coast
could even be a degree or two higher. These factors will likely
cut into snowfall accumulations. Across interior NE NJ, the
Lower Hudson Valley, and southern CT snow is expected through
day break Tuesday.
The intensity of the precipitation will diminish by sunrise
Tuesday, but light snow is still expected inland with a mix
down towards the coast. There will be a transition to cold rain
across the NYC metro and Long Island. Surface temperatures
should rise into the middle 30s the rest of the morning and then
potentially upper 30s in the afternoon. Loss of deeper
saturation aloft will be a main factor in the precip changing
over to a cold rain from south to north through the day.
Lift and drier air should continue to work around the low south
and east of Long Island through the day which should bring an
end to precip from west to east. It will likely take until late
day for light snow or a light rain/snow mix to end completely
across southeast CT. Any additional snow accumulation during the
day Tuesday across the interior will be light and mainly in the
morning.
Snowfall forecast of 5 to 7 inches across the warning area with
generally 3 to 5 inches in the Advisory area. Amounts across
the southern Boroughs and southern Long Island (south of the
LIE) will be lower, generally closer to 2 to 3 inches. If the
warming aloft is less and surface temps end up a bit colder,
these amounts could be slightly higher, especially closer to the
coast. At the same time, if warmer air moves in aloft and at
the surface, then amounts could be lower near the NYC metro and
Long Island. There is higher confidence in amounts across
interior NE NJ, Lower Hudson Valley and southern CT. The snow
will be wet and relatively low ratio, except the interior which
likely ends up closer to 10:1.
&&
.SHORT TERM /TUESDAY NIGHT/...
The low pressure will move well south and east of the area
Tuesday night with high pressure building in from the west. A
progressive upper ridge axis will translate east over the area
through the night leading to clearing skies. Dry conditions are
expected with lows ranging from the upper teens to around 20
degrees well north and west to the 20s and low 30s elsewhere.
There will likely be some light NW flow as the high builds in,
but the snowpack inland could lead to slightly colder
temperatures.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Southern branch of the polar jet like most of this season will
remain the dominant stream across the lower 48 this period, but
a fast flow will keep the pattern active. Another late week
storm system eerily reminiscent of the early week storm will
bring another bout of precipitation to the area Friday into
Saturday. The ECMWF and Canadian have come much farther north
with this system the last 48h, nearly lining up with the GFS,
but just south. While this system is looking warmer with more
rain versus wintry precipitation, there is a blocking 50/50 low
that will keep a colder northern branch airmass in place across
eastern Canada and New England. The question is the southern
extent of this airmass and how much cold air will be available
for the system. A secondary low develops across the Mid Atlantic
and takes a hard right turn just south of the area Friday
night, while the primarily low tracks up into eastern Great
Lakes. The ptype forecast could be a challenging one. At this
time, forecast includes a change to rain at the coast Friday,
with a mix inland. A strong pressure gradient to the north will
also produce a strengthening east flow Friday into Friday night
with gales to possibly storm force gusts in the offshore waters.
Before then, high pressure over the area Wednesday exits quickly
to the east as a weak frontal system bring rain showers to the
area. Another high with somewhat colder air builds in late
Thursday into early Friday before exiting ahead of the next
storm system.
Temperatures warm back up to above normal levels Thursday with
highs getting into the 50s and lows in the 30s to around 40
Thursday morning. Following a cold frontal passage Thursday
afternoon/evening, more seasonable temperatures return to the
area Friday into Saturday. However, the late week storm track
will be a big factor in the temperature forecast.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Low pressure impacts the region with wintry weather, changing to
rain along the coast toward Tuesday morning, and into
northeastern New Jersey during the morning, continuing through
tonight and into Tuesday morning, before tapering off and ending
during the afternoon. Conditions IFR to LIFR and at times
VLIFR.
A gusty, 20-25kt, E/SE flow into the overnight, and then back
to E/NE late overnight and into Tuesday morning with the winds
diminishing and gusts ending. Winds then back to N and NW.
Timing of the wind shifts and strength of the winds and gusts
will be dependent on the movement of low pressure through the
region.
Runway Accumulations:
KJFK/KISP: 2-4 inches (wet and slushy)
KLGA/KEWR/KTEB: 3-5 inches (wet and slushy)
KHPN/KBDR/KGON: 4-6 inches (wet and heavy)
KSWF: 6-8 inches (wet and heavy)
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Precipitation type and changeover timing may be off by a few hours.
There is a low chance of VLIFR conditions for a time tonight in
heavier snow.
There is uncertainty with the timing of the wind shifts and strength
of the winds and gusts, which will be dependent on the movement of
low pressure through the terminals.
OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
Tuesday Night...VFR.
Wednesday...VFR. Slight chance of rain in the afternoon into the
evening.
Thursday...MVFR or lower conditions in rain.
Friday-Saturday...MVFR or lower conditions in rain/snow, ending
Saturday afternoon, then becoming VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
No changes made to the marine headlines. Increasing E flow will
bring winds on the ocean to around gale force and to SCA levels
on the non-ocean waters tonight into Tuesday morning as the
pressure gradient tightens due to low pressure developing south
of the waters. Winds should relax through the morning on
Tuesday, but SCA conditions may persist longest on the eastern
LI Sound and eastern LI Bays. Ocean seas will remain elevated
through the middle of the week with SCA likely needed.
Otherwise sub-SCA conditions can be expected Wednesday and
Thursday. Following a cold frontal passage Thu aft/eve, there
could be a marginal SCA in a NW flow. An approaching storm will
then bring the potential for an easterly gale Friday night into
Saturday morning, especially for the ocean waters.
&&
.HYDROLOGY...
No hydrologic impacts are expected through next weekend.
&&
.TIDES/COASTAL FLOODING...
A Coastal Flood Advisory remains in effect for the south shore
back bays of Nassau county for the early Tuesday morning high
tide cycle.
A strengthening easterly flow ahead of an approaching storm system
Monday afternoon and night, with near gale-force gusts, will produce
a storm surge of 2-3 ft. This will bring the potential for minor
coastal flooding along vulnerable locations. The highest
probability for exceeded these benchmarks will be across the
south shore back bays of Nassau county, where an advisory
remains in effect. Elsewhere, water levels should remain below
minor flooding benchmarks and no additional headlines are
planned at this time.
Another storm system at the end of the week brings the
potential for another round of coastal flooding. It`s too early
to be specific with details due to uncertainty with the storm
track.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Storm Warning until 3 PM EST Tuesday for CTZ005>008.
Winter Storm Warning until 10 AM EST Tuesday for CTZ009>012.
NY...Winter Storm Warning until 1 PM EST Tuesday for NYZ067>070.
Winter Weather Advisory until 1 PM EST Tuesday for NYZ071>075-
078>081-176>179.
Coastal Flood Advisory from 1 AM to 4 AM EST Tuesday for
NYZ179.
NJ...Winter Storm Warning until 1 PM EST Tuesday for NJZ002-004-103.
Winter Weather Advisory until 1 PM EST Tuesday for NJZ006-
104>108.
MARINE...Small Craft Advisory until 9 AM EST Tuesday for ANZ331-335-338-
345.
Small Craft Advisory until 1 PM EST Tuesday for ANZ332-340.
Gale Warning until 9 AM EST Tuesday for ANZ350-353-355.
&&
$$
SYNOPSIS...DS/DW
NEAR TERM...DS/DW
SHORT TERM...DS
LONG TERM...DW
AVIATION...MET
MARINE...DS/DW
HYDROLOGY...DS/DW
TIDES/COASTAL FLOODING...//
Area Forecast Discussion
National Weather Service Blacksburg VA
927 PM EST Mon Feb 27 2023
.SYNOPSIS...
A frontal system will move rapidly through the area tonight.
accompanied by brief showers and followed by very gusty west
winds overnight and through Tuesday morning as deep low pressure
skirts by to our north. High pressure will briefly build over
the region Wednesday before another system drifts into the
region Thursday and stalls resulting in multiple waves of rain
and possibly thunderstorms. Heavy rain is possible Thursday and
Friday with temperatures remaining above normal.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 915 PM EST Monday...
High Wind Warning and Wind Advisory remain in effect...
Band of moderate to heavy showers was east of Danville and
Lynchburg and extended from the Chesapeake Bay to central North
Carolina at 9:00PM. The warm front was slowly lifting north
across southern Virginia and the New River Valley with winds
becoming gusty from the southwest following the front. This
boundary will likely accelerate or be overtaken by the
approaching cold front. Based on the HRRR and HREF, expecting
the cold front to reach the Blue Ridge by 06Z/1AM. Have
refreshed the probability of precipitation based in the latest
radar trends and Hi-Res guidance.
This guidance had the winds turning to the west and wind speeds
consistently increasing overnight, peaking around 1:00AM with
gusts of 40 to 60 mph. In the foothills and piedmont maximum
winds will occur between 1AM and 6AM behind the front.
Temperatures behind the cold front are warmer than some
locations north of the warm front this evening. Have some spots
close to the lows already. No changes to non-diurnal temperature
trends.
As of 620 PM EST Monday...
A push of rainfall is moving through the region this evening.
This will be relatively short-lived, perhaps raining for about
30 minutes to and hour as it quickly moves to the east. Main
surface front is still over Central Kentucky, but will see
increasing southwest winds as it approaches tonight and may
even see some warming as the weak wedge erodes under a strong
pre-frontal jet. Still expect strong west winds behind the
front, especially in the higher terrain.
As of 215 PM EST Monday...
Fast progressive westerly flow remains in place across the
U.S. with a series of embedded vigorous disturbances continuing
to track from the Pacific west coast eastward across the
continental U.S. One such system will track across the forecast
area tonight bringing a brief round of showers followed by
strong and gusty winds overnight. Wind gusts of 50 to 60 mph are
possible across the higher terrain of the Blue Ridge from
Watauga northeast toward Fancy Gap, which has prompted the need
to upgrade the earlier issued Wind Advisory for this region to a
High Wind Warning for tonight and early Tuesday. Much of the
remainder of the CWA along and west of the Blue Ridge will be
under a Wind Advisory for the same time frame. Look for
sustained 15-25 mph winds at the lower elevations east to 25-35
mph across the higher elevations with higher gusts. Winds will
diminish fairly quickly Tuesday afternoon as the rapid
progression of systems from west-to-east continues allowing high
pressure to build in for Tuesday night and Wednesday.
QPF with this evening`s activity is expected to be light and
will diminish with eastward extent, especially east of the Blue
Ridge. Amounts are expected to average around 1/4 inch, with
less east of the Blue Ridge. An isolated rumble of thunder is
possible across southeast WV but surface based instability is
limited at best. The strong gusty gradient winds will be the
main headline for the next 12-18 hours.
With respect to temperatures, no significant change of air mass
accompanies this current weather system. This is another
Pacific-based air mass that has acquired continental
characteristics as it traveled across the U.S. with no source
of Canadian or Arctic air at all. Thus, with a wedge in place
across much of the area today holding temperatures down into the
40s and 50s, it will actually be warmer in most areas Tuesday
with more sunshine and westerly downslope flow east of the Blue
Ridge.
/Confidence Levels in Forecast Parameters/
- Moderate to High Confidence in Temperatures,
- Moderate Confidence in Precipitation Probabilities,
- Moderate to High Confidence in Wind Direction and Speed.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 230 PM EST Monday...
Multiple rounds of potentially heavy rain expected Wednesday
night through Thursday night...
Tuesday night into Wednesday an axis of high pressure will move
into, over, and then east of the region. The result will be winds
trending light and variable Tuesday night, then becoming southwest
and increasing during the day Wednesday. This southwest trajectory
will help bring a return of moisture into the region. This will be
realized in an increase in cloud cover across the area Wednesday
afternoon. Temperatures will also be high on average across the area
Wednesday as compared to those of Tuesday.
Wednesday evening and overnight, a southern stream shortwave trough
is expected to progress eastward from the Mid-Mississippi Valley
into the Tennessee Valley. Showers associated with this system will
gradually spread across the area Wednesday night from west to east
with the best coverage across the southern half of the region.
Guidance is leaning toward the potential of some isolated
thunderstorms late Wednesday night across the far southwest portion
of the forecast area. For now, confidence is not high enough to
include any in the forecast. By mid-day Thursday, the bulk of the
precipitation associated with the system is expected to be east of the
area with only some lingering isolated/scattered showers, again the
best coverage across the southern sections.
On the heels of the Wednesday night system will be yet another
southern stream system moving this time through the Lower
Mississippi Valley Thursday night. In advance of this system,
guidance is showing good consensus on the development of a warm
front in advance of the upper low moving north towards, and the
into, the area late Thursday afternoon through Thursday night. A
generous swath of moisture is expected coincident to this warm
front. Rainfall totals from Wednesday night through Thursday night
are expected to range from around one inch across the northeast
portion of the region to one inch and one-half to one and three-
quarters inches across the far southwest portions of the region.
Temperatures during this portion of the forecast will trend milder,
reaching values around twenty degrees above normal by Thursday.
Confidence in the above weather scenario is moderate to high.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 1245 PM EST Monday...
A cold front will with showers, and perhaps a few storms, will
cross the area Friday, followed by drier and cooler weather for the
weekend...
On Friday morning, an area of low pressure is expected to be heading
northeast through the Arklatex region, arriving across the eastern
Great Lakes/Mid-Atlantic region by late Friday night. As it
progresses, so too will its associated surface low, and that
feature`s appended warm front, then cold front. The warm front will
already be either heading north through the area Friday morning, or
will be north of the area Friday morning. Look for a broad swath of
rain to accompany this feature. By the afternoon, especially late
afternoon, look for the precipitation to turn showery in advance of
the approaching cold front. This front is expected to reach far
western sections by the late afternoon, and eastern section by the
early evening. Showers are expected to be robust with this front,
with perhaps some isolated storms across mainly the southern half of
the region. Guidance forecast LI values are slightly negative in
this area along with a few hundred J/kg of CAPE during the afternoon
in areas mainly south of Route 460.
Friday night, lingering showers are expected across eastern sections
during the evening hours. As winds shift north, look for a brief
period of isolated upslope rain/snow showers across far western
Greenbrier County.
Prior to the wind shift after the frontal passage, winds will
gradually veer through the day and trend stronger and gustier as the
warm front lifts north and the cold front approaches from the west.
As we head into and through the weekend, surface high pressure will
work its way into the area from the west. Concurrently, weak
disturbances on the west side of the departing eastern Great Lakes
upper low may dip south through the Ohio Valley. These features may
help maintain partly cloudy to mostly cloudy skies across southeast
West Virginia, along with isolate rain/snow showers.
By Monday, the center of the surface high will be shifting east of
the area, allowing winds to trends southwest. We will see slightly
milder temperatures Monday, with the potential for increasing
clouds in the west.
Temperatures during this portion of the forecast are expected to
trend from fifteen degrees above normal on Friday to near normal by
Sunday. Monday will be just a few degrees above normal.
Confidence in the above weather scenario is moderate.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
As of 630 PM EST Monday...
Strong weather system will move through the region overnight.
Expect gusty west winds to develop across the higher terrain in the
west this evening then spread east overnight. A High Wind Warning is
in effect for Watauga, Grayson, Ashe, Alleghany, and Carroll with a
Wind Advisory for areas east to along the Blue Ridge.
Ceilings...MVFR overnight in the west and low end VFR east with
brief MVFR-IFR possible in rain showers.
Visibilities...VFR for the most part. Brief MVFR visibilities
possible in showers and low clouds.
Winds...Southwest this evening 10-20 mph and gusty, especially west
becoming west to west-northwest 15-30 mph with gusts to 50-55 mph
west and 15-20 mph with gusts to 45 mph east overnight through
Tuesday morning. Winds diminish quickly Tuesday afternoon.
Extended Aviation Outlook...
High pressure will provide mostly VFR conditions by Tuesday
afternoon through most of Wednesday.
A series of low pressure systems will track into the region along a
lingering frontal boundary Thursday through Friday. Widespread rain
and sub-VFR ceilings are expected for an extended period Thursday
through Friday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...High Wind Warning until 9 AM EST Tuesday for VAZ015-016.
Wind Advisory until 9 AM EST Tuesday for VAZ007-009>014-
017>020-022>024-032>035.
NC...High Wind Warning until 9 AM EST Tuesday for NCZ001-002-018.
Wind Advisory until 9 AM EST Tuesday for NCZ003-019.
WV...Wind Advisory until 9 AM EST Tuesday for WVZ042>044-507-508.
&&
$$
SYNOPSIS...PM/WP
NEAR TERM...AMS/BMG/RAB
SHORT TERM...RAB
LONG TERM...DS
AVIATION...BMG