Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/27/23
Area Forecast Discussion
National Weather Service Charleston SC
948 PM EST Sun Feb 26 2023
.SYNOPSIS...
High pressure will extend across the region into Monday. A cold
front will move through the region Monday night into early
Tuesday. A stronger cold front could affect the area late week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
No major changes were made for the late evening update. Near
term guidance is still pointing to a foggy overnight period
across Berkeley and Charleston Counties with a potential for
dense fog. The development of dense fog closer to the coast
will likely have to wait until surface winds drop there a bit a
bit more, but ceilings are slowly lowering suggesting stratus
build-down is in progress.
The main forecast concern for tonight centers on fog over parts
of the Charleston Tri-County area. There are increasing signals
that marine stratus developing off the Charleston County coast
in the vicinity of a weak stationary front could slowly build
down and transition to fog overnight as it spreads onshore.
Guidance is essentially mixed on how widespread and dense the
fog will become with some of the favored statistical members
pointing to very little fog and stratus development, while most
of the high-res members, with support from the HREF, CONShort
and LAV data sets, showing a fairly significant dense fog event
evolving over parts of Charleston and Berkeley Counties
overnight. 1000 hPa condensation pressure deficits are not
progged to become overly low south of the Santee River with only
the NAM12 showing values low enough to support widespread dense
fog. However, the RAP and H3R are all pointing to dense fog
despite relatively high condensation pressure deficits in their
respective runs. This leads fairly low confidence on how the fog
situation will evolve overnight.
Given the trends noted in the higher-res data, the decision was
made to hit the fog forecast a bit harder, highlighting "areas
of fog" for areas roughly along/north of the I-26 corridor and
expanding into parts of James Island, Johns Island and West
Ashley, including Downtown Charleston. Opted to old off on any
mention of dense fog with low vsbys for now given the
uncertainties noted above, but it is very possible Special
Weather Statements and even a Dense Fog Advisory may be needed
overnight as trends become more apparent.
It will be a relatively warm night with lows only dropping into
the upper 50s/lower 60s, except mid 50s north of the front near
the Santee River.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Low amplitude short-wave ridging/larger scale subsidence will be
in place across the SE CONUS to start the period. Strong mid-level
short-wave and attending surface low pressure will be advancing
up into the Great Lakes region which will nudge a weakening
boundary through the Ohio Valley and toward the southeast late
Monday into Monday night. There may also be a secondary surface
low developing off the mid Atlantic coast Monday night that
helps to nudge a secondary boundary down through the region.
Ahead of the boundary on Monday, axis of lower level theta-e air
will be pivoting up into our region on increasing southwesterly
flow and may lead to the development of some modest instability
across the region. Recent CAM guidance does hint at the
possibility of some shower activity developing Monday afternoon
and into Monday night ahead of the secondary boundary. However,
forecast soundings appear fairly capped above 800 mb, enough so
that I`d prefer to leave our going dry forecast intact.
Otherwise, with increasing southwesterly flow, temperatures
should easily warm into the lower 80s and perhaps a touch
warmer in the GA counties. Current forecast max temps are below
record readings for February 27. Finally, deeper mixing will be
able to tap stronger winds aloft with gusts of 18 to 25 knots
becoming common during Monday afternoon. It will be close for
Lake Wind Advisory criteria to be met on Lake Moultrie, and
think gusts will remain largely under 25 knots. Thus, no
headline at this juncture.
Low amplitude mid level ridging and surface high pressure
rebuild across the region for Tuesday through Wednesday and we
should see a good amount of sunshine overall. Stretch of above
normal temperatures will persist with highs in the lower to
middle 80s for most areas, cooler along the coast.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Larger scale flow pattern will be rather progressive through
the midweek period with broad W/SW flow aloft, warm air
entrenched across the Deep South, and an active storm track from
the southern Plains into the Great Lakes. Early in the period,
trailing frontal system is still looking to stretch out from the
mid Atlantic into eastern Texas with some precipitation likely
developing along the boundary....some of which may try to sneak
into our area on Thursday/Thursday night.
Heading into the latter half of the week and into the weekend,
a stronger piece of short-wave energy will be digging a bit
further into the southern CONUS, spinning a strong surface low
that will pivot up through the Appalachian/Ohio Valley region on
Friday and driving a strong cold front through the SE CONUS
through Friday night. There remains a bit of uncertainty on the
exact track of this system. But the system does have the
potential to bring very gusty winds to our region (EURO/GFS peg
55-65 knots 1000 MB geostrophic winds across our area Friday and
>80 knot 500 MB winds), possible marine and land based wind
headlines, as well as the potential for severe weather. In fact,
SPC Day 6 Outlook has our region in a 15 percent probability
for severe storms. Will have to keep an eye on how this evolves
as we go through the week.
After FROPA, cooler weather returns heading into the weekend
with readings heading back down to near normal for early March.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
KCHS/KJZI: Low confidence on how fog and stratus will evolve
overnight. Guidance is mixed in showing marine stratus
gradually building down and transitioning to fog this evening
and overnight, which could impact both terminals. Some of the
more reliable near term guidance is favoring the foggier
scenario and with marine stratus already noted just offshore per
coastal webcams, the 00z TAFs will offer lower conditions
compared to the previous 18z TAF cycle. Still favored a
somewhat conservative solution limiting KCHS to MVFR with both
vsbys/cigs dropping below alternate minimums at KJZI. It is very
possible both terminals could drop to airfield minimums,
especially at KJZI. Trends will be watched closely and
amendments will be issued as needed. VFR should return to both
terminals by mid- morning with gusty winds dominating from mid-
morning through 00z Tuesday.
KSAV: VFR. Risk for fog and stratus will remain well to the
north of the terminal. Gusty winds will occur mid-morning
through 00z Tuesday.
Extended Aviation Outlook: Gusty southwest winds are anticipated
across the region for Monday afternoon through Monday night, and
a window of flight restrictions is possible at the terminals later
Monday night into Tuesday as a weak front moves through the
region. Periodic flight restrictions and gusty winds are
possible again Thursday and Friday as a strong system rolls
through the region.
&&
.MARINE...
Vsbys in the Charleston Harbor have tanked and reports from the
Charleston Pilot Boat indicate the fog is slowly expanding
offshore. A Marine Dense Fog Advisory has been issued until 9 AM
for Charleston Harbor and the South Santee-Edisto Beach
nearshore leg.
Tonight: Areas of marine stratus could transition to areas of
fog over parts of the South Santee-Edisto Beach Nearshore leg
and Charleston Harbor later this evening and overnight.
Confidence on how low vsbys will get remains low, but vsbys 1 NM
or less are a possibility. A Marine Dense Fog Advisory could be
needed. East to southeast winds will gradually transition to
southwest overnight with speeds less than 10 kt. From Edisto
Beach south over the remainder of the marine area, south to
southwest winds will prevail with winds 10 kt or less. Seas will
average 1-2 ft nearshore waters and 2-3 ft Georgia offshore
waters.
Monday: Gusty southwest winds develop across the coastal waters
Monday afternoon through Monday night. Solid Small Craft
Advisories are anticipated during this time but will hold off
issuing Advisory headlines for now given it`s more than 24 hours
out. However, some gale force gusts are possible across the
Charleston nearshore waters Monday night and have opted to hoist
a Gale Watch for that marine zone.
Tuesday through Friday: Winds and waves diminish for Tuesday
through midweek. But, winds and waves will be ramping up again
for Thursday through the rest of the work week, with gale force
gusts possible again on Friday.
&&
.CLIMATE...
A *preliminary* record high min as been set at KSAV with a low
of 64 observed so far. The record high min for the date is 63
set in 1939. The record will not be officially set until after
the climate day ends and official climate products, including
the record report, is issued early Monday morning.
Record High Temperatures:
February 26:
KCHS: 83/1996
KCXM: 80/1944
KSAV: 84/1996
February 27:
KCHS: 84/1962
KCXM: 83/1962
KSAV: 86/2021
Record High Minimum Temperatures:
February 28:
KCHS: 63/2021
KCXM: 64/2017
KSAV: 66/2021
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Dense Fog Advisory until 9 AM EST Monday for AMZ330-350.
Gale Watch from Monday evening through late Monday night for
AMZ350.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
509 PM CST Sun Feb 26 2023
...AVIATION UPDATE...
.DISCUSSION...(This evening through Sunday)
Issued at 440 PM CST Sun Feb 26 2023
-- KEY MESSAGES FOR THE ENTIRE 7-DAY FORECAST:
* By FAR the main forecast issue (and obviously the most imminent
one) is our first official (albeit low-end) threat for a few
strong/severe thunderstorms in 2023, with our main window of
opportunity 6 PM-2 AM. SPC`s latest Day 1 outlook clearly
focuses the official Marginal Risk near/especially south of the
NE/KS border, but we are not discounting the possibility of a
few stronger storms (with at least a small hail threat) farther
north into our Nebraska counties.
* Although not expected to be a significant/widespread concern,
there appears to be a decent chance for a good chunk of
especially the southeast half of our coverage area (CWA) to pick
up a quick 0.25-0.50" rain tonight (localized higher
possible/likely), which given the partially to mostly still-
frozen soils, could lead to at least minor/nuisance flooding (a
bit more than would normally see from fairly modest rain
amounts).
* As showers/storms vacate overnight, attention turns to strong
northwest winds (gradient winds/non-convective) on the back side
of the system. Although have very slightly toned-down our wind
forecast from previous, a good chunk of Monday AM will likely
feature widespread gusts of 40-50 MPH before winds gradually
ease down during the afternoon.
* Looking beyond these next 24 hours, a brief rundown of forecast
highlights include: 1) outside chance for a shot of light rain
and/or snow in our northern CWA Tuesday (not really in the
official forecast at all presently)...2) The possibility (far
from a sure thing!) of at least some light accumulating snow
mainly during the Wed night-Thurs time frame.
-- More details/further info building upon the Key Messages above
(see short-term specific paragraphs farther below for details
focused solely on the first 36 hours):
1) Changes worth noting from previous forecast (along with
greatest uncertainties):
- Honestly there have been truly "major" changes from the previous
forecast package, both in the short/longer term periods. On the
fairly minor side of things: 1) high temps nudged up very
slightly for Monday...2) Snow chances (PoPs) Wed night-Thurs
nudged up slightly (but still below "likely" percentages"),
although latest deterministic model data would currently suggest
that most of our CWA could easily stay dry/snow-free.
2) General overview of the large-scale/surface upper air pattern
along with longer-term precip potential (and any key model
differences):
Honestly, the latest ECMWF/GFS and its associated numerical
guidance are current in pretty remarkable throughout the ENTIRE
7-day, not only aloft but also at the surface in terms of frontal
timing/temps etc. Briefly summarizing the 7-day situation:
First the incoming vigorous shortwave/closed low plows across KS
into MO/southern IA overnight (sparking our rain/storm chances).
In it wake, we spend a few days in fairly broad/low amplitude
quasi-zonal to slightly southwesterly flow, during which time
we`ll have to watch for "sneaky" light precip chances (such as
what especially the ECMWF suggests in our north Tues daytime).
Then, the next primary larger scale shortwave trough approaches
and eventually passes mainly to our south across OK/TX during the
Wed night-Thurs time frame. Although this wave COULD produce some
accumulating snow (mainly of the light variety) within our domain,
the higher-confidence effect will be a one-day cool down (centered
on Thursday). In the wake of that system, Friday appears to be a
pretty high-confidence dry (and slightly warmer) day. Between Fri
night-Saturday, another weaker trough is progged to cross the
Central Plains out of the west-northwest, but at least for now,
our forecast remains void of mentionable (15+ percent) PoPs given
only weak/disorganized QPF signals. Finally, benign quasi-zonal
flow returns by Sunday, which for being a full week out currently
carries pretty high confidence in being dry and milder.
3) Brief temperature overview:
As a whole, these next 7 days will average out slightly above
normal (2 weeks out still showing decent signs of prevailing
somewhat colder per ECMWF ensemble and latest CPC 8-14 Day
outlook). But getting back to this upcoming week: Seasonably-mild
Mon-Tues with highs mainly most areas 50s. A cool-down starts Wed
with highs mainly 40s and then Thursday the outright-chilliest day
with highs 30s and Thurs night lows teens. This colder snap is
short-lived though as highs rebound well into the 40s Fri-Sat and
then a decent signal for widespread 50s (some 60s south?) Sunday.
--SHORTER TERM DETAILS FOCUSED SOLELY ON THE NEXT 36 HOURS/3
FORECAST PERIODS:
- CURRENT RECENT/CONDITIONS SO FAR TODAY:
At least for a short time longer, our CWA remains rain-free, as
showers/storms are already erupting not far to our southwest in
western KS. As expected, it`s been a seasonably-mild day (what an
INCREDIBLE turn-around from 48 hours ago!), with highs on track to
top out somewhere in the 50s most areas, with warmer 60s common
along/south of the state line and even our extreme southwest
corner (Rooks Co. area) flirting with 70. In the big picture,
water vapor satellite and short term model data clearly depict a
"powerhouse" trough churning east-northeast along the CO/NM border
toward KS. At the surface, the associated low pressure center has
deepened to around 990 millibars along the southern KS/CO border.
In response to the pressure falls today, southeast winds have
responded accordingly, currently averaging sustained 15-20
MPH/gusts 25+ MPH (likely 30+ far south). Skies have remained
mostly sunny through the day, with low stratus skirting more to
our east although high- level cirrus (including plentiful
convective blowoff) will steadily continue invading from the
west- southwest.
- THIS EVENING-OVERNIGHT:
The stage is set for a rainy (and in various places) stormy
evening overnight. Although the very first showers/storms could
enter our extreme southwestern CWA by 6 PM, the vast majority of
"action" will focus between 6 PM-2 AM as widespread
showers/embedded thunderstorms track across much of the CWA from
west-southwest to east-northeast. On the large scale, the heart of
the powerful mid level wave/closed low will track diagonally
across KS from southwest-northeast overnight, reaching northern MO
by 12Z/6AM. The associated surface low will follow suite, passing
just over or barely south of our far southern CWA a few hours
either side of midnight (around 985 millibars by then), and then
exiting to northwest MO/southwest IA by 6 AM. With the main
surface low and primary surface/low level instability axis passing
to our south, our CWA is clearly not "ground zero" for a severe
storm threat (and thus lies well north of the Enhanced/Moderate
Risk areas to our south. That being said, with 0-1 kilometer CAPE
up to around 500 J/kg expected to invade mainly our KS zones this
evening (and higher elevated CAPE in the 850-700 millibar layer)
perhaps up to 500-1000 J/kg up to roughly around I-80), there will
be enough instability for at least limited severe. Surface based
instability SHOULD remain weak enough (and nocturnal inhibition
strong enough) to preclude a QLCS tornado threat in our south, but
with very strong deep layer shear of 50+ knots and with at least a
brief period of strong low level shear of 30-40+ KT, especially
our KS zones (Marginal Risk area) will need watched for a damaging
wind threat (60+ MPH), especially if the northern fringes of the
MAIN squall line/linear complex surges into that area. Farther
north, while most of our Nebraska CWA is not officially in the
Marginal area, high-res models suggests enough aforementioned
elevated CAPE that a sneaky nickel-quarter size hail threat COULD
extend roughly as far north as I-80 if things come together just
right. On top of actual convective concerns, we are at least
modestly-concerned about localized, mainly minor flooding
overnight. Although "official" QPF forecast call for the highest
amounts to be only 0.25-0.50" and mainly in our southeast half,
some of the latest HRRR/NAMNest runs are bit more concerning
showing at least isolated stripes of 0.50-1.00" rain potential in
parts of our south/east and maybe central. While this would
normally not be of great concern during the warm season, the
ground is still partially to mostly frozen (we only have around 1"
of surface thaw here at our WFO this afternoon), so any heavier
rain could run off fairly quickly. For sure, the main concern is
brief/short term flooding of typical flood-prone areas, and we are
less concerned about river flooding/ice jam flooding given the
overall-modest train amounts and overall-low river levels.
Something to keep an eye on though. ALL convection should vacate
our far eastern CWA no later than 3-5 AM.
In addition to the convective/possible hydro issues, northwest
winds will start cranking up on the back-side of the departing low
late in the night (especially after 3-4 AM). Typically-reliable
higher res wind progs (such as from HRRR) suggest we SHOULD be
"safe" from Warning criteria gusts of 58+ MPH, gusts of 40-50 MPH
are certainly likely.
Lastly, and on the more mundane side, low temps overnight should
bottom out in the mid-upper 30s most areas (perhaps holding up
around 40 far southeast).
- MONDAY DAYTIME:
Aloft, the big trough will rapidly continue its eastward
departure, centered over the OH area by 00Z/6PM while the
associated surface low reaches southern MI. Locally, by far the
main story Monday will be fairly strong northwest winds,
particularly during the morning hours as the pressure gradient
remains tight on the backside of the departing low and diurnal
mixing at least partially taps into very strong low-level winds
for a time. Fortunately, models do not show full/efficient deep
mixing or we might be talking Warning level winds. Even so, the
entire CWA can expect sustained speeds of mainly 25-35 MPH/gusts
40-50 MPH for at least a few hours Monday morning. Fortunately,
winds will gradually back off in the afternoon, with late
afternoon/early evening sustained speeds only 10-20 MPH/gusts
15-25 MPH. Unless some lower clouds linger a bit in east-northeast
zones for a time, skies should be sunny/mostly sunny. Nudged up
high temps 1-2 degree most areas, ranging from around 50 far north
to low 60s in KS zones (mid 50s Tri Cities). Fortunately relative
humidity levels should hold up far enough to preclude fire weather
issues (along with the recent rainfall), but will need to watch
especially Rooks Co. in our far southwest for perhaps a few hours
of near-critical fire weather.
- MONDAY NIGHT:
High confidence dry, although mid-high level clouds will gradually
increase into especially our northern half (mainly post-midnight)
as a weak disturbance approaches from the west-southwest. Once the
late afternoon-early afternoon breezes subside, most of the night
will only feature winds of 5-10 MPH, gradually turning from
northerly to easterly. Not currently a strong signal for fog
issues, but this will bear watching, especially in places where
ground remains wet from tonight`s rain. Low temps were changed
very little, mainly mid-upper 20s most areas.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 508 PM CST Sun Feb 26 2023
Precipitation over NW KS will move into the TAF sites this
evening. Currently thinking SHRA, but there is a small chance for
VCTS this evening also. I TEMPO`d lower ceilings and vis with
heavier showers, but that could change if a TSRA moves into the
TAF sites. Ceilings are forecast to go IFR this evening and the
HRRR drops vis to IFR also so figure a TEMPO should cover those
conditions initially. The winds will shift from SE to NW tonight
and gusty winds and LLWS are likely behind the SFC low. The winds
will slowly taper off tomorrow and by evening will be NW
10-15kts.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Pfannkuch
AVIATION...Beda
Area Forecast Discussion
National Weather Service Grand Rapids MI
957 PM EST Sun Feb 26 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 939 PM EST Sun Feb 26 2023
The ongoing forecast looks good with no significant changes made.
A large area of moderate to heavy precipitation was developing in
eastern NE southward into KS. This was associated with the
developing surface wave in central KS. This feature deepens as it
tracks northeast tonight into Monday...expanding the precipitation
as is approaches MI. Surface temperatures were below freezing
across the CWA. The surface temperatures are predicted to climb
slowly Monday morning as the precipitation moves in. It still
looks like by the time the precipitation reaches Kalamazoo and
Battle Creek...surface temperatures should be a few degrees above
freezing based off the latest guidance. As a result we will not
expand the WSW further south at this time. However...we will need
to monitor the trends through the remainder of the night as it
will be a close call for possible impacts for the Interstate 94
corridor Monday morning. Further north for the Muskegon to Grand
Rapids to Lansing area...there will be a delay in when the surface
temperatures climb above freezing so it does look like impacts
will occur from the freezing rain...starting up Monday morning.
Northeast of Grand Rapids it may stay below freezing for most of
the day on Monday. Thus the impacts will last there longer and
they will be more widespread. However that region may see sleet
and snow mixing in at times which would limit the freezing rain
accretion duration. Still more than a quarter inch of freezing
rain is possible in that region.
&&
.DISCUSSION...(This evening through next Sunday)
Issued at 258 PM EST Sun Feb 26 2023
- Wintry Mix for Monday -
Tranquil weather tonight is followed by the leading edge of mixed
precip moving from southwest to northeast on Monday morning. The
Winter Weather Advisory issued early this morning follows the
timing and precip type forecast from a blend of the HRRR and
global models which have slowly converged towards a solution that
has shifted the axis of heavier freezing rain, on the order of
two tenths of an inch or more, to the north central and northwest
forecast area, with more sleet and snow and less icing across the
northeast.
An occluded low combines with a retreating cold high to set up a
period of overrunning warm air and surface cold advection on
easterly winds during the morning that will give a brief period of
icing along and just south of I-96. A short duration advisory will
cover that threat from Allegan to Ingham Counties. This area will
be dry-slotted and warm above freezing after the initial burst of
mixed precip. Further north, the threat will persist longer with
the dry slot lifting to the northern zones by late afternoon, but
wraparound showers of mixed precip persisting into the evening
across the far northeast where 2 to 5 inches of snow along with
some sleet and freezing drizzle are possible for Osceola and Clare
Counties.
South of I-96 we expect mostly rain with close to an inch of QPF.
This will cause some rises on local rivers and streams but at
this point we do not expect river flooding.
The DGZ loses saturation after 00Z so only light precip is
expected during the evening and impacts from any freezing drizzle
will be mitigated by the coating of what fell previously.
- Light snow or mix for Wednesday, colder end of the week -
A weak low pushes an area of f-gen across Lower Michigan on
Wednesday with some rain or snow, but marginal surface
temperatures should mean travel impacts will be minimal. A couple
inches of snow accumulation are possible in any persistent f-gen
forced mesoscale bands. Colder weather follows for the end of the
week and we will have to watch the southern stream low tracking
across the Ohio Valley on Friday. The GFS is currently a northern
outlier and brings significant snow to our forecast area while the
ECMWF and Canadian remain further south but the northern edge of
the precip shield clips SE Lower Michigan.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 630 PM EST Sun Feb 26 2023
A storm system will track into the TAF sites Monday morning
bringing a variety of hazards to the TAF sites. The thermal
profile supports a wintry mix in the morning...but as the warmer
air continues to advect in...the sites will transition to rain for
the afternoon. Wind shear will also be possible especially Monday
morning. A strengthening low level jet tracks in from the south
and will likely top 50 knots. This feature combined with the lower
surface wind speeds will generate the hazardous conditions. IFR
and lower conditions will spread in during the morning...and
persist into the afternoon. How quickly those conditions develop
is a little uncertain as the low levels will initially be dry as
the precipitation moves in.
&&
.MARINE...
Issued at 225 PM EST Sun Feb 26 2023
Gale Warning for Monday with east gales to 35 knots. There will be
a period of west winds to 30 knots in the cold advection on the
back side of the departing low Monday night into Tuesday, so a
Small Craft Advisory will be needed for that period.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory from 9 AM to 5 PM EST Monday for MIZ037-
043-050.
Winter Weather Advisory from 9 AM to 8 PM EST Monday for MIZ038-
044>046-051-052.
Winter Weather Advisory from 9 AM to 10 PM EST Monday for MIZ039-
040.
Winter Weather Advisory from 7 AM to 3 PM EST Monday for
MIZ056>059.
Winter Weather Advisory from 7 AM to noon EST Monday for
MIZ064>067.
LM...Gale Warning from 5 AM to 4 PM EST Monday for LMZ844>849.
&&
$$
UPDATE...MJS
DISCUSSION...Ostuno
AVIATION...MJS
MARINE...Ostuno
Area Forecast Discussion
National Weather Service Gray ME
756 PM EST Sun Feb 26 2023
.SYNOPSIS...
High pressure builds later tonight and Monday followed by a
complex system bringing snow to the region Monday night through
Tuesday. Another brief area of high pressure crosses Wednesday
followed by a broad area of low pressure that will bring
mountain snow, and rain or snow south of the mountains
Thursday. Behind this system will be another brief period of
high pressure Friday with potential for another system to track
near the East Coast next weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
750 PM...A band of more robust snow showers moving through SE NH
and southern York county should be offshore in the next hour.
this could produce a quick coating of snow. Otherwise fairly
clear should persist outside of the mtns and in srn NH
overnight. Temps may rise a few degrees with front pushing
through but will fall again after midnight, so no significant
changes.
Previously...Light snowfall is expected to gradually wind down
with not much in the way of additional accums into early this
evening across most of the area. However, locations just east of
a Lewiston to Brunswick line and toward the Midcoast could see
an inch or so of snow could occur over the next couple hours,
but potential seems to be diminishing as the latest volume scans
from GYX are showing a weakening trend in the reflectivity.
Will also keep a low-end chance of snow showers a little longer
into the evening across NH and southwestern ME as the HRRR and
NAMnest continue to suggest this as a possibility.
Otherwise, a dry north to northwest flow will take over this
evening and tonight as the low pressure and front continue to
exit to the east. This will end the snow shower potential for
most, except for the upslope snow showers toward and in the
mountains. However, these will also lessen in coverage during
the nighttime hours. Cloud cover will also gradually diminish
south of the mountains overnight, so temperatures should be able
to fall pretty quickly once enough clearing occurs. Forecast
lows are generally in the single digits, except some teens
across the south and along the coast. However, the normally
colder spots could approach zero.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/... Broad high pressure
builds in for Monday resulting in a dry day with partly sunny
skies, with clouds starting to increase in the late afternoon or
early evening hours ahead of our next storm system. Max temps
are expected to reach the mid to upper 20s for most of the
region and near 30 degrees across southern NH.
Going into the evening and nighttime hours, a complex low pressure
system will quickly moves across the Great Lakes and Ohio Valley
regions toward the Northeastern U.S, which is expected bring another
round of accumulating snow to the area. There will be some dry air
aloft to overcome initially, but with the column continuing to
moisten steadily increasing isentropic lift across the area, light
snow is expected to overspread the region from south to north from
late Monday evening into the overnight hours. Based on latest
guidance, snow should start reaching the surface across
southern NH give or take an hour or two either side of midnight,
and then slowly expanding to the north and east across
central/northern NH and western ME through the course of the
night. With a couple of inches possible during the overnight
hours and light snow expected to be ongoing as we approach
daybreak, a slick morning commute is certainly possible. More
details below.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Busy pattern continues with several short wave troughs moving
across or at least near the region this coming week into the
weekend.
The long term period starts off with what looks like a snowy
Tuesday for most, and a winter storm watch has been posted for
zones that at this time appear most likely to achieve 6"+ snow
accums. The bulk of the watch is across Maine, and this is where
several models have slightly better forcing for ascent due to a
low level trough and frontogenetic zone as the approaching short
wave trough "tugs" on well-offshore low pressure. Some ocean
enhancement may occur as well. The precipitation tapers off and
ends after midnight Tuesday night as the short wave trough
passes through. Both commutes on Tuesday will be affected by
slippery conditions.
The weather pattern remains busy as Midweek may bring another
significant precip producing system centered around Thursday.
This one, at least initially, looks a bit warmer so mixed
precipitation types will probably come more into play with this
next one.
There will be a really short break before the next short wave
trough approaches, which could bring another wintry system
Friday and/or Saturday.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Short Term...Light to occasionally moderate snow will continue the
possibility of MVFR ceilings with visibilities ranging from IFR to
MVFR. Precipitation will gradually wind down with visibilities
improving later this afternoon into this evening. Ceilings may take
a little longer to improve, but most sites should return to VFR by
late this evening. VFR expected at all sites during the day
Monday. Light snow will then overspread New England from south
to north Monday evening and Monday night resulting in IFR
visibilities and MVFR to IFR ceilings.
Long Term...IFR conditions are expected for much of the day
Tuesday in snow. Conditions improve to VFR Wednesday before
another system impacts the region Thursday with potential for
MVFR to IFR conditions in RA and/or SN starting Wednesday night.
&&
.MARINE...
Short Term...Weak low pressure moves across the waters this
afternoon into tonight bringing a round SCA conditions through
tonight. Conditions improve Monday as high pressure builds in, but a
low pressure moving off the Mid-Atlantic will bring increasing
easterly winds and deteriorating conditions Monday night.
Long Term...Low pressure passing south of the waters Tuesday
will bring increasing easterly flow and seas building to around
10 ft. Easterly winds will bring at least SCA conditions with
potential for a period of Gales along the outer waters. Winds
drop below SCA thresholds Tuesday night into Wednesday while
elevated seas likely bring SCA conditions through Thursday. An
increase in winds is likely on Friday.
&&
MONDAY
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Watch from late Monday night through Wednesday
morning for MEZ012>014-018>028-033.
NH...Winter Storm Watch from late Monday night through Wednesday
morning for NHZ004-006-008>010-015.
MARINE...Small Craft Advisory until 9 AM EST Monday for ANZ150-152.
Small Craft Advisory until 10 PM EST this evening for ANZ154.
&&
$$
NEAR TERM...Cempa/Combs
SHORT TERM...Combs
LONG TERM...Ekster
Area Forecast Discussion
National Weather Service Hanford CA
232 PM PST Sun Feb 26 2023
.SYNOPSIS...The first in another series of storm systems will
begin to impact the region late this afternoon. Rain, mountain
snow, and gusty winds will continue at times through Wednesday.
Dry weather is forecast on Thursday and Friday but freezing
temperatures are likely across much of the San Joaquin Valley both
mornings.
&&
.DISCUSSION...
The next storm system set to impact central California continues
to drop south out of the Gulf of Alaska. Warming and some peeks of
sun ahead of this approaching low pressure system are providing us
with temperatures this afternoon around 6 to 9 degrees higher
than yesterday`s cold and cloudy/rainy conditions. An area of
precipitation sliding southward ahead of the approaching upper
low is consolidating into a band about 70 miles to the north of
our area and will will begin to move into our area by around 4 PM.
HRRR model pushes this band through central California overnight,
bringing around one tenth of an inch or less of additional
rainfall to the west side of the San Joaquin Valley and as much as
three to four tenths of an inch on the east side. Snow levels are
progged around 2000 to 3000 ft overnight, above which several
inches of additional snow will accumulate, up to around 18 inches
in the higher elevations. A Winter Storm Warning is in effect for
the Sierra Nevada and foothills beginning at 4 PM. The
precipitation will begin impacting the Kern County mountains by
early Monday morning. Snow levels are progged to be at or below
the elevation of the major highway passes again, and accumulating
snow is expected to bring additional travel disruptions. A Winter
Storm Warning is in effect for the Kern County mountains beginning
at 4 AM Monday morning.
As the upper low swings inland Monday morning, the trough will
push into the California coast, and another round of precipitation
will move into central California. This will bring similar amounts
of rainfall in the San Joaquin Valley through Tuesday morning
along with around 2 feet of additional snow in the higher
elevations of the Sierra. Increased winds will accompany the
passing trough and create blowing snow impacts. A Blizzard Warning
will therefore be in effect for the higher Sierra beginning 10 AM
Monday morning. Winds are projected to gust up to 25-30 mph in the
San Joaquin Valley Monday, which could be enough to topple some shallow
rooted trees in saturated soils.
A third wave of precipitation Tuesday into Wednesday will bring
around one Quarter to one half inch of additional rainfall to the
Valley and up to 3 to 4 more feet of snow over the high Sierra.
Low snow levels continue through the period and the Winter Storm
Warnings continue for the Kern County Mountains and the Sierra
foothills through 4 PM Wednesday, in addition to the Blizzard
Warning for the higher Sierra Nevada.
Model ensemble solutions indicate a drier northwesterly flow by
Thursday and Friday behind the exiting systems, then another
winter storm system dropping into he region by Sunday. Blended
model guidance predicts overnight low temperatures will drop to
around the freezing mark in the San Joaquin Valley, with around a
75 to 95 percent chance of low temperatures at or below 32 degrees
early Thursday morning.
&&
.AVIATION...Mountain obscuring IFR conditions with precipitation
spreading north to south after 00Z Monday. Local MVFR/IFR in rain
across the San Joaquin Valley after 00Z Monday. Elsewhere VFR
conditions will prevail across the central CA interior for the
next 24 hours.
&&
.AIR QUALITY ISSUES...
On Monday February 27 2023, Fireplace/Wood Stove Burning Status
is: No Burning Unless Registered in Fresno and Madera Counties.
Burning Discouraged in Kern, Kings, Merced, and Tulare Counties,
and Kern (Greater Frazier Park Area) and Sequoia National Park and
Forest.
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
and/or to provide feedback.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 4 PM this afternoon to 4 PM PST
Wednesday for CAZ318-320-322.
Winter Storm Warning from 4 PM this afternoon to 10 AM PST
Monday for CAZ323>331.
Blizzard Warning from 10 AM Monday to 4 PM PST Wednesday for
CAZ323>331.
Winter Storm Warning from 4 AM Monday to 10 PM PST Wednesday for
CAZ332>336.
&&
$$
public...JEB
aviation....JEB
weather.gov/hanford
Area Forecast Discussion
National Weather Service Indianapolis IN
1003 PM EST Sun Feb 26 2023
.Forecast Update...
Issued at 957 PM EST Sun Feb 26 2023
The forecast remains on track with only minor adjustments made to
match observations. Current surface analysis shows a strong low near
the central plains and a weak high across the Mid-Atlantic. This
low will move towards the Great Lakes Region and lead to a
tightening pressure gradient late tonight into Monday. Expect
winds to begin increasing overnight as a result. GOES16 shows a
large area of high clouds associated with this system already
streaming into central Indiana. Clouds will continue to increase
in coverage and rain will begin later tonight as a warm front
lifts north.
&&
.Short Term...(This evening through Monday)
Issued at 220 PM EST Sun Feb 26 2023
- Wind Advisory Monday; Gusts to 50 MPH possible.
- Rain expected on Monday; Thunderstorms possible.
Surface analysis early this afternoon shows a large area of high
pressure in place from the deep south, across Indiana to the Great
Lakes and Ontario. Aloft, water vapor showed deep low pressure over
the American southwest (which will become a big player in our
weather on Monday), with ridging building across the plains states.
This was resulting in lee side subsidence across the Ohio Valley. A
tropical plume of moisture was streaming across TX within the ridge
and extended toward the Ohio and Tennessee River Valleys. GOES16
shows high clouds associated with this plume streaming across the
southern half of Indiana. Dew points across the area were in the
lower to mid 30s.
Tonight...
Increasing clouds will be expected tonight, with scattered rain
showers developing late. The previously discussed upper low across
the southwestern states is expected to make quick progress across
the plains toward Illinois overnight. Initially this evening the
ridging aloft to the west is expected to continue to build across
Indiana and the Ohio Valley leading to continued subsidence along
with warm air advection through the overnight period. However, As
the upper low pushes across the plains, associated surface
cyclogenesis is expected to occur over Kansas. The 295K Isentropic
surface shows the arrival of strong isentropic lift over Indiana
ahead of the approaching low, with specific humidities over 8
g/kg. Forecast soundings suggest a gradual saturation through the
night with a saturated column arriving near 12Z and pwats over 1
inch. Given the flow of the tropical plume arriving in the Ohio
Valley, this should result in increasing clouds along with the
development of showers late as the column becomes saturated as the
forcing dynamics increase with the approach of the Low pressure
system from the west. HRRR suggest showers arriving from the
southwest late tonight within the isentropic lift. Thus will
continue with a dry forecast this evening, but increasing pops
overnight especially after 09Z. Given the ongoing warm air
advection, expect steady or slowly rising temps overnight. Lows
temps within the 12 hour tonight period will be achieved during
the evening prior to the arrival cloud cover and warm air
advection as temps in the lower 50s will be common by sunrise on
Monday.
Monday...
An active weather day is in store on Monday. The previously
mentioned surface low is expected to track across northern Illinois
to Michigan through the day, deepening all the way. The past of this
system will keep Central Indiana within the warm sector. Due to the
deepening low, a strong low level jet is expected to pass across
Central Indiana with speeds in excess of 60 knots at 850mb. As
expected, the surface pressure gradient is sharp. Aloft, the
associated upper system also is expected to push across Indiana
through the day becoming negatively tilted through the process.
These features will result in favorable forcing dynamics as forecast
soundings remain deeply saturated though much of the day and pwats
remain over 1 inch. Forecasts soundings fail to show much in the
way of instability, and remain mainly saturated moist adiabatic.
Given the favorable forcing and moisture along with an approaching
surface cold front associated with the system, showers and perhaps a
thunderstorm will be expected. Due to the strong winds aloft and the
strong pressure gradient, any downburst could allow some of the
stronger winds aloft to mix downward. Thus for now the ongoing wind
advisory will continue as a windy day with high gusts appears
reasonable. Gusts on Monday could reach near 50 mph, causing tree
damage and possible power outages, and damage to unsecured objects.
Will use categorical pops, but given the expected clouds and rain
will try to keep highs contained to the lower 60s.
&&
.Long Term...(Monday night through Sunday)
Issued at 220 PM EST Sun Feb 26 2023
Tuesday and Wednesday...
Much quieter weather will ensue for the beginning of the Long Term
as weak high pressure builds in a modest CAA regime Monday night.
Any cold air intrusion will be brief as the Ohio Valley remains
in generally S-SW flow with broad troughing over the Inter-
Mountain West. A weak shortwave looks to develop along a mid level
jet Tuesday night that will further reinforce this southerly
flow, pushing temperatures well above normal by mid-week. Cannot
rule out light rain showers on Wednesday within a corridor of
isentropic lift and moisture return, but greatest QPF should
remain south within stronger dynamics as a secondary low develops
over the Mississippi Valley.
Thursday through Saturday...
The main focus on the long term will be on the impending development
of a deep low pressure system late next week. Currently, this lobe
of energy is over the northern Pacific, but will traverse down the
Western Coast, eventually entering a favorable cyclogenesis
environment over the desert SW. After which ensemble member are
widely varied on low track, but are fairly consistent on deep
cyclogenesis somewhere over the Great Lakes/Ohio Valley region.
Current thoughts are for this system to gradually trend northward
as snow depth to the north and mid week warmth help develop a
quasi-baroclinic zone, but many potential solutions, including
snow are still in play.
One feature to keep an eye on will be the placement of a potential
surface high over Ontario. The push of CAA along the CCB will
greatly impact the temperature gradient north of the warm front, and
if this high continues to trend eastward, less cold air could lead
to above freezing temperatures and therefor a cold rain instead
of snow. Still enough possibilities remain for an impactful winter
event, and should be closely monitored in the coming days.
&&
.Aviation...(00Z TAF Issuance)
Issued at 635 PM EST Sun Feb 26 2023
Impacts:
* VFR Conditions until late tonight.
* Lowering ceilings to MVFR and IFR arriving overnight with rain
* Strong winds start early Monday with LLWS
Discussion:
High pressure across the region will continue to provide VFR
conditions this evening.
Late tonight, a strong area of low pressure will begin to advance
toward Indiana from the plains. Ceilings will lower quickly with
MVFR ceilings expected at all sites by 05-07Z and becoming IFR
shortly after that. Some locations could see brief LIFR conditions
late tonight into tomorrow morning as showers and storms move
through.
Furthermore, a strong pressure gradient is expected to be present as
the deep upper low and associated surface low pass. Models show a 60-
65 kt low-level jet developing which will result in LLWS tomorrow as
the surface low passes due to both speed and direction.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 7 AM to 7 PM EST Monday for INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
Update...Melo
Short Term...Puma
Long Term...Updike
Aviation...Melo
Area Forecast Discussion
National Weather Service Midland/Odessa TX
514 PM CST Sun Feb 26 2023
...New AVIATION...
.SHORT TERM...
(This afternoon through Monday night)
Issued at 120 PM CST Sun Feb 26 2023
* Significant Windstorm Expected This Afternoon and Evening
An active afternoon and evening is ahead for Southeast New Mexico
and West Texas, as a potent trough and its attendant jet move over
the region. The aforementioned trough is currently located near the
AZ/NM state line, and per latest satellite imagery and RAP analysis
is beginning to develop a subtle negative tilt. Clouds from this
morning continue to clear from west to east, with a stout low-level
jet resulting in gusty southerly to southeasterly winds across the
Trans Pecos and Permian Basin, with southwesterly winds
overspreading western areas in association with a pre-frontal
trough. The gusty winds we see right now are likely the lightest
winds we`ll see until after midnight tonight, as the trough
translates east-northeastward, dragging an anomalously strong
Pacific front (for this time of year) through the region. This front
will produce a sharp westerly wind shift, with widespread wind gusts
expected to reach 50-70mph across the lower elevations, and up to 95-
105mph across the Davis, Guadalupe, and Delaware Mountains. Current
satellite imagery also indicates a swath of blowing dust advecting
northeastward out of northern Chihuahua, MX, and this dust will
overspread the region this afternoon and evening, with widespread
blowing dust expected and localized significant visibility
reductions possible, especially along the Pacific front as it moves
through the area.
In addition to the winds and dust, thunderstorms will also be
possible late this afternoon and early evening, mainly across the
eastern Permian Basin. Storms that develop would likely be high-
based to start with, with significant downward momentum yielding an
enhanced wind threat, though brief rainfall and large hail would be
possible. Storm motion would likely be upwards of 60kt to the east-
northeast, with greater potential for strong to severe thunderstorms
expected over the Rolling Plains northeastward into western and
central Oklahoma. One other variable this afternoon into this
evening is also widespread elevated fire weather conditions across
Southeast New Mexico and West Texas, with concern for fire starts
due to potential downed power poles/arcing power lines, as well as
lightning strikes over eastern areas. Any fires that begin could
spread quickly in the dry and windy conditions, and more on the fire
threat can be found in the Fire Weather Discussion below.
As the Pacific front moves east of the region tonight, cooler and
drier air will filter into the region, with winds gradually
diminishing as the gradient slackens and with a loss of mixing.
Continued westerly flow will will maintain mild overnight
temperatures with lows in the 30s and 40s. While winds will diminish
overnight, high winds will persist across the mountains, where the
High Wind Warning remains in effect through Monday evening. In a
post-frontal regime, highs Monday will top out cooler than today,
but still above normal for late February, in the middle 60s and
lower 70s for most. Monday evening, relief (albeit, brief) from the
high winds will arrive in the Guadalupe and Delaware Mountains as
winds diminish with the departure of the midlevel jet. Lows will
once again drop into the middle 30s and 40s for most, with the light
winds making for a pleasant night.
&&
.LONG TERM...
(Monday through Saturday)
Issued at 120 PM CST Sun Feb 26 2023
* Another high wind event forecast for west Texas and
southeastern New Mexico Thursday...
We will see a short period of short wave ridging before yet
another potent upper level system reloads over the desert
southwest and approaches west Texas and southeastern New Mexico
Wednesday and Thursday. Prototype cluster analyses of 500 hPa
ensemble height anomalies suggests to me to have two modes...one
mode where the system is slower in translating eastward over the
desert southwest and maintains closure whereas the second mode is
more progressive and opens the low into a wave over the southern
Rockies. Since the trend has been for systems to beat themselves
against a persistent southeastern US ridge and that the massively
negative NAO doesn`t seem to go anywhere anytime soon per ECMWF
and GEFS ensembles, we`ll stick with the more open solution,
keeping the bulk of precipitation (such as it will be) north of
the Permian Basin Wednesday night into early Thursday. Thursday
appears to be another windbag event, with the ECMWF Extreme
Forecast Index and SoT looking pretty gnarly. While not as
significant as the ongoing windbag event, wind gusts near
hurricane strength are likely over the Delaware/Guadalupe ranges
with high wind warning criteria met or exceeded across much of the
adjacent plains. And after that system passes, we`ll see some
quasizonal flow through next weekend. Meaning things should get a
little quieter for awhile. Don`t count on it lasting, though.
Regrading sensible weather, highs Tuesday and Wednesday will be
about 10 degrees above normal under southwesterly flow aloft.
Would be warmer but there could be extensive cirrus near us ahead
of this system. May see some showers across southeastern New
Mexico and the northern Permian Basin late Tuesday/early Wednesday
but QPF will be scant. Then another Pacific front plows through
the region Thursday morning, dropping highs to slightly below
early March normals. Winds should subside Thursday evening, and
with lighter winds and very good radiational cooling expected,
lows Friday morning will be a bit on the nippy side, ranging from
the lower 20s near Tatum, NM to the mid 30s along the Rio Grande.
From there, temperatures trend to near normal with no
precipitation expected.
bc
&&
.AVIATION...
(00Z TAFS)
Issued at 454 PM CST Sun Feb 26 2023
Very strong southwest winds are overspreading all terminals with
the strongest winds at the western most terminals. Gusts up to
50-60 kts are possible through the early evening. As the highest
winds initially hit, blowing dust may drop visibility to IFR.
Visibilities will slowly recover after initially falling. Winds
begin to decrease, becoming westerly, after sunset but remain
strong. Winds decrease further after midnight.
&&
.FIRE WEATHER...
Issued at 341 PM CST Sun Feb 26 2023
* At request of local officials have issued a Red Flag Warning
for Southeast New Mexico until 8 PM MST.
* Elevated fire weather conditions expected all week...
The ongoing high wind event will make for IA concerns in any
ignition this afternoon and evening with ERCs at or below the 50th
percentile. There will be some RH recovery overnight, mitigating
concerns some, but Monday looks to be another breezy day,
especially from southeastern New Mexico south to the Big Bend.
Drying continues Tuesday with winds a bit stronger. Wednesday and
Thursday look to be the windiest days, but RH recovery will be
better and therefore fine fuels may bounce back a bit before the
Pacific front slams the area. IA concerns, however, will be
present all week. Obligatory PSA: emphasize to people to not be
buttheads and keep those lit cigarettes in their vehicles, not
carelessly tossed out onto fuels which could start a wildland
fire. Also check to see that those hauling trailers are not
dragging chains, and for folks to avoid activities which may
generate sparks like welding or trash burning or parking running
vehicles in tall grass.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 39 72 41 77 / 10 0 0 0
Carlsbad 34 70 40 71 / 0 0 0 0
Dryden 46 82 46 85 / 0 0 0 0
Fort Stockton 42 75 43 81 / 0 0 0 0
Guadalupe Pass 35 59 40 63 / 0 0 0 0
Hobbs 31 67 39 70 / 0 0 0 0
Marfa 33 68 35 76 / 0 0 0 0
Midland Intl Airport 38 72 42 76 / 0 0 0 0
Odessa 39 72 44 76 / 0 0 0 0
Wink 36 72 39 77 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
TX...High Wind Warning until 10 PM CST /9 PM MST/ Monday for Davis
Mountains-Guadalupe Mountains Above 7000 Feet-Guadalupe and
Delaware Mountains.
High Wind Warning until midnight CST tonight for Andrews-Borden-
Central Brewster County-Chinati Mountains-Chisos Basin-
Crane-Davis Mountains Foothills-Dawson-Eastern Culberson
County-Ector-Gaines-Howard-Loving-Lower Brewster County-
Marfa Plateau-Martin-Midland-Pecos-Presidio Valley-Reeves
County Plains-Scurry-Van Horn and Highway 54 Corridor-Ward-
Winkler.
Wind Advisory until midnight CST tonight for Glasscock-Mitchell-
Reagan-Terrell-Upton.
NM...Red Flag Warning until 8 PM MST this evening for Chaves Plains-
Eddy Plains-Lea-Sacramento Foothills and Guadalupe
Mountains.
High Wind Warning until 9 PM MST Monday for Guadalupe Mountains
of Eddy County.
High Wind Warning until 11 PM MST this evening for Central Lea
County-Eddy County Plains-Northern Lea County-Southern Lea
County.
&&
$$
SHORT TERM...84
LONG TERM....72
AVIATION...91
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
932 PM CST Sun Feb 26 2023
.UPDATE...
Issued at 918 PM CST Sun Feb 26 2023
We just finished up a pretty sizable update to the forecast to
incorporate the latest trends that we are seeing from the early
arriving 00z guidance (so CAM heavy at this point). Main story here
is this continued the trend the previous discussion mentioned of an
eastward shift in the heaviest precipitation. This resulted in a
roughly 25% reduction in QPF across the board, even where the
heaviest precip is still expected in western WI. In addition, this
update keeps temps up in the mid 30s in western WI through the
afternoon, which also took a further hit out of the snowfall forecast
there, though the p-type in western WI continues in the afternoon
continues to sit on a knifes edge to falling as more snow or more
rain. After all of these updates, we did end up dropping a few more
counties from the advisory in MN. Douglas and Pope were dropped as
precip is looking unlikely to make it that far west and Kandiyohi,
Meeker, and Wright where the combination of less QPF and warmer temps
greatly reduced the icing forecast. In the metro, left Anoka and
Washington counties in the Advisory, though it`s the northern,
exurban areas of those counties that look to have the potential for
icing conditions.
&&
.DISCUSSION...(This evening through Sunday)
Issued at 310 PM CST Sun Feb 26 2023
KEY MESSAGES:
- Freezing rain and significant icing expected across most of western
Wisconsin late tonight and early Monday.
- Model consistency for impacts on the western edge of Monday`s
system remains very poor, but confidence is slowly beginning to
improve.
- Another round of light snow likely Tuesday night and Wednesday.
A vigorous and compact upper low over the southern Rockies will
begin to turn east northeast toward the mid Mississippi Valley
tonight as it encounters the strong mid level ridge over the
southeast. The trend today reversed yesterday`s trend by shifting the
storm back to the east. It seems most of the guidance is beginning
to converge on this idea with the 18Z NAM more in line with the 12Z
GFS and ECMWF. There is very little time left for any more large
swings, so confidence is increasing. The NBM forecast for this
afternoon is based primarily off of last night`s model runs, so some
significant manual edits were necessary to tamp down that solution
in favor of the current trend. There will need to be more work done
this evening to further refine QPF and resultant snow and ice
accumulations. This is especially true across east central Minnesota
and northwest Wisconsin where QPF may end up about half of what is
currently forecasted. Confidence remains high enough to maintain the
entire Winter Storm Warning in Wisconsin. No changes to headline
type was made, aside from dropping the advisory across parts of far
western Minnesota due to the drier solution.
Precipitation will lift north rapidly late tonight, engulfing
southern/eastern MN and WI by early Monday morning. Very warm air
aloft will ensure no snow, and it should melt all hydrometeors
completely to make sleet difficult to achieve too. What`s left is a
surface temperature forecast hovering around freezing to determine if
precipitation falls as plain rain or freezing rain. With a breezy
east-southeasterly flow mostly originating from the current chilly
airmass in place, not expecting temperatures to rise above freezing
before precipitation begins across central MN and western WI. There
may be a period of several hours freezing rain is occurring as
precipitation rates increase into early Monday morning. This aspect
of the forecast has remained pretty consistent and forecast ice grids
remain near 1/4 inch across most of west central WI.
By late Monday morning, temperatures should rise to the warm side of
freezing and end any further icing threat. By afternoon, the back
edge of precipitation will clear from southwest to northeast and
could mix with a little light snow before ending. With temps still
above freezing, snow accumulation will remain light.
Quick on the heels of the early week system, another will track east
into the northern Plains Tuesday into Wednesday. This one won`t have
as much moisture to work with and a narrower band of precipitation is
likely on its northern half. Frontogenetic bands tend to shift north
and south and there has been little consistency with the track, so
confidence remains low. The system could still drop a few inches of
snow anywhere across the Dakotas, Minnesota, and northern Wisconsin.
PoPs remain relatively low for now until greater consistency
develops, but some likelies are now in place across central MN.
High pressure builds in for the rest of the period and another shot
of colder air will return late week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 600 PM CST Sun Feb 26 2023
As noted in the main discussion, we continue to see western MN dry
out, to the point now where we kept the AXN TAF dry, with the back
end of the precip shield expected to be within 20 miles east or west
of RWF. With the HRRR bringing the precip shield just west of RWF,
did keep -RA mention going there. CIGS are expected to drop pretty
quick to between 400 and 800 feet as the precip moves in. Through
15z, the warm nose looks strong enough to keep p-types all liquid.
Between 15z and 18z this warm nose collapses, with the surface temps
driving a type of fzra/ra to determining whether it`s rain or snow by
18z. -FZRA is still expected to be the predominate p-type at STC,
with RNH/EAU warming above freezing and transitioning to -RA around
15z/16z. As the precipitation is ending, -SN chances increases,
especially at STC, but for MSP/RNH/EAU, temps are currently forecast
to stay too warm while precip is still in place in the afternoon to
drive much of a -SN threat.
KMSP...Some brief periods of -fzra are possible between 6z and 9z,
but by the time the main precip shield gets to MSP between 9z and
10z, it will be warm enough to keep this as a cold rain. For the last
6 hours of the TAF, it becomes a question of how quickly does the
stratus clear out. Right now, that looks to happen between 2z and 5z.
/OUTLOOK FOR KMSP/
Tue...VFR. Wind W 5-10 kts.
Wed...MVFR likely. Chc IFR/-SN. Wind NE 10-20 kts.
Thu...VFR. Wind N 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Winter Weather Advisory from 3 AM to 3 PM CST Monday for Benton-
Chisago-Isanti-Kanabec-Mille Lacs-Morrison-Stearns-Todd.
Winter Weather Advisory from 3 AM to 10 AM CST Monday for Anoka-
Sherburne-Washington.
WI...Winter Weather Advisory from 3 AM to 10 AM CST Monday for Pepin-
Pierce.
Winter Storm Warning from 3 AM to 6 PM CST Monday for Barron-
Chippewa-Polk-Rusk.
Winter Storm Warning from 3 AM to 10 AM CST Monday for Dunn-Eau
Claire-St. Croix.
&&
$$
UPDATE...MPG
DISCUSSION...Borghoff
AVIATION...MPG
Area Forecast Discussion
National Weather Service Morristown TN
951 PM EST Sun Feb 26 2023
...New UPDATE...
.UPDATE...
Issued at 942 PM EST Sun Feb 26 2023
Forecast is progressing as expected. A strong shortwave across the
Great Plains will quickly move northeast toward the Ohio Valley
and Great Lakes by Monday afternoon. A 140 kt upper jet across the
Great Lakes through the Mid-Atlantic will create an environment
favorable to intensification of a surface low across the Ohio
Valley. Strong gradient winds and a strong pressure gradient
across the mountains will result in windy conditions area-wide,
even for the valley, with mountain wave high winds across the
mountains and western foothills. Have updated and continued the
Wind Advisories and High Wind Warning.
JB
&&
.SHORT TERM...
(This evening through Monday Night)
Issued at 239 PM EST Sun Feb 26 2023
Key Messages:
1. Windy and warm conditions Monday along with numerous to
widespread showers and a slight chance of some isolated thunder.
Discussion:
A stationary boundary remains in place to our south and the
associated weak moisture convergence and saturated vertical profile
has lead to persistent low clouds blanketing the region. Some
light showers have been observed along and south of the I-40
corridor throughout the late morning and afternoon, with a few
surface observations reporting some light drizzle as well. Lack of
any large scale forcing has kept any QPF amounts little to none.
Nonetheless, the majority of radar returns have dissipated at this
point and most areas will remain dry until the increase of
showers ahead of a cold front tomorrow, though spotty light
rain/drizzle cannot be totally ruled out late this evening and
early Monday morning.
The main impact with Monday`s weather system remains the wind. A
strong pressure gradient will develop as surface low pressure
tracks from the Mississippi River Valley to the Great Lakes
region, in addition to the development of an anomalous LLJ.
Mixing heights upwards of 3500-4000ft and the strong pressure
gradient will result in widespread southwesterly wind gusts of
40-50 mph by late morning and towards the evening hours. The 12Z
HRRR and NAM3km both suggest that pockets of southwesterly flow at
850mb cloud amplify to as much as 60-70kts. While direction seems
unfavorable for any downslope or mountain wave enhancement as the
strongest flow settles in, I would not be shocked to see higher
elevations reach high wind criteria. As such, have upgrade the
previous wind advisory to a high wind warning in the GSMNP portion
of the East Tennessee mountains. Gusts upwards of 65 mph will be
possible.
Outside of wind impacts, showers will become numerous to
widespread by mid-day. Models have continued to trend with
shifting the better forcing a little further north, minimal
instability, and lackluster mid-level lapse rates. As such, SPCs
marginal risk has been shifted further north. A few isolated
rumbles of thunder remain a possibility. Temperatures will be well
above normal under the strong southwesterly flow.
&&
.LONG TERM...
(Tuesday through next Sunday) Issued at 239 PM EST Sun Feb 26
2023
Key Message:
Repeated rounds rainfall will potentially affect the area
Wednesday night through Friday, with a possible threat of
strong/severe storms Thursday into Friday.
Discussion:
A break from the rain and wind is expected on Tuesday with mostly
clear skies and warm temperatures across the area as surface high
pressure combines with a quick building mid-level ridge. These quiet
conditions will likely only last for Tuesday and Wednesday before
return to a rainy and stormy pattern for the second half of the work
week.
A frontal boundary will move into the area and should stall
out in the vicinity of the Tennessee Valley. This boundary will
become a focus for continued rainfall, moderate to heavy at times,
from Wednesday night through Friday when it gets forced out from a
strong low kicking out through the Ohio Valley on Friday. With quasi-
stationary boundaries like this one, the forecast models can
dramatically change QPF bulls-eye`s as time goes on, so there is not
very high confidence in exact rainfall amounts at this time. But
confidence is increasing that there will be rounds of moderate to
heavy rainfall between Wednesday night into Friday. At this time
expect widespread rainfall totals of over 2 inches between Wednesday
and Friday, with isolated higher amounts due to the
isolated/scattered nature of these showers. Some locations could see
over 4 inches of rain for the second half of the week. So flooding
will be the main weather concern, especially on Thursday night into
Friday after rainfall from the previous days.
In addition to the heavy rainfall and flooding potential, the strong
low kicking out through the Ohio Valley thursday into Friday will
bring with it a chance for strong to severe thunderstorms in the
eastern Tennessee Valley. Still some large discrepancies on the
exact location of the low and the most unstable atmosphere ahead of
it, but will keep monitoring the trends for the potential of severe
storms.
Once the system finally moves through we`ll move into a drier and
cooler pattern over the weekend with temperatures coming back down
to seasonal normals.
&&
.AVIATION...
(00Z TAFS)
Issued at 618 PM EST Sun Feb 26 2023
Poor flight conditions continue tonight into Monday as low clouds
and areas of drizzle will persist near TYS and TRI tonight with
MVFR and locally IFR cigs. Cigs lower at CHA later tonight with
IFR conditions as S/SE flow and increasing moisture result in
upslope conditions. SSW winds increase on Monday with gusts near
40 kt possible at all sites during the afternoon hours. These very
strong near-surface winds will present a hazard to aviation on
Monday afternoon. As convective showers move east across the
region, locally stronger gusts will be possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 56 73 50 73 / 0 70 10 0
Knoxville McGhee Tyson Airport, TN 53 72 49 68 / 10 80 10 0
Oak Ridge, TN 53 70 47 69 / 10 90 10 0
Tri Cities Airport, TN 50 70 47 65 / 20 80 20 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Wind Advisory from 10 AM to 7 PM EST Monday for Cherokee-Clay.
TN...Wind Advisory from 10 AM EST /9 AM CST/ to 7 PM EST /6 PM CST/
Monday for Anderson-Bledsoe-Bradley-Campbell-Claiborne-East
Polk-Grainger-Hamblen-Hamilton-Hancock-Hawkins-Jefferson-
Johnson-Knox-Loudon-Marion-McMinn-Meigs-Morgan-North Sevier-
Northwest Blount-Northwest Carter-Northwest Cocke-Northwest
Greene-Northwest Monroe-Rhea-Roane-Scott TN-Sequatchie-
Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan-
Unicoi-Union-Washington TN-West Polk.
High Wind Warning from 10 AM to 7 PM EST Monday for Blount Smoky
Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains.
VA...Wind Advisory from 10 AM to 7 PM EST Monday for Lee-Russell-
Scott VA-Washington VA-Wise.
&&
$$
SHORT TERM...KRS
LONG TERM....ABM
AVIATION...JB
Area Forecast Discussion
National Weather Service Pueblo CO
701 PM MST Sun Feb 26 2023
.UPDATE...
Issued at 655 PM MST Sun Feb 26 2023
Have let Winter Weather Advisories come down for the southwest
mountains and watching another increase in winds occuring along
the eastern slopes of the southeast mountains, though so far they
have not been as high as earlier NBM had suggested. High res
models such as HRRR and early time steps of the 00z NAMNest
suggest potential for high winds will continue through 1 AM in the
gap flow areas along the southern I-25 corridor region. Will let
High Wind Warnings continue with Pueblo and Eastern Fremont county
expected to come down around 9 PM. -KT
UPDATE Issued at 505 PM MST Sun Feb 26 2023
Based on latest high res model data and current forecast have
extended the High Wind Warning for the southern Sangre De Cristo
mountains until 08z in line with other high wind warnings along
the southern I-25 corridor. The stronger gusts will stay confined
to the lower eastern slopes where gusts up to 85 mph will be
possible as the storm system rapidly intensifies across western
KS. Have allowed all other scheduled High Wind Warnings to expire
along the lower Arkansas River Valley, San Luis Valley and for the
northern Sangres, Wets and Wet mountain Valley. Will need to watch
the Pikes Peak region closely for a brief window of high wind
gusts across the lower eastern slopes and western side of El Paso
county this evening. Cross-sections do not look particularly
favorable for mountain wave development and think the limited
coverage should preclude the need for a High Wind Warning, but
will be watching trends in observations and mesonet stations
closely in case these conditions change.
&&
.SHORT TERM...(This evening through Monday)
Issued at 252 PM MST Sun Feb 26 2023
Key messages:
1) Strong winds the main concern the remainder of this afternoon
into this evening.
2) Isolated thunder should push east by late this afternoon.
3) RED FLAG conditions over parts of the region tomorrow with gusty
winds continuing.
Impressive trough is moving over the region as I write. 3h P change
chart is impressive, showing 10-11 mb pressure drops and 5-6 mb
pressure rises behind the low. This indicates the surface cyclone is
rapidly intensifying. Radar shows bands of showers and snow showers
stretching SW-NE over the region, with some TSRA south of Baca
county moving into SW KS as of 2 pm. KSPD has been gusting to 55
knts for awhile now.
Rest of today into tonight...
I believe any convection should be out of the region by mid to late
afternoon. This convection will already enhance the strong winds
which are already over the region. The main concern is going to be
as the sfc system pushes east, the Isalobaric component (rapid
sfc pressure drop) of the wind is going to allow strong winds to
accelerate out of the mountains, and we will continue to have a
high wind threat linger over the east slopes of the mtns,
especially winds coming off Pikes Peak the wet mtns. For this
reason I have extended the warning for Pueblo county into the
evening hours and have added E Fremont into the warning. These
strong winds will then continue over the s tier of the plains into
late evening.
With the winds keeping up tonight, plains will remain relatively
warmer with low son the U20s to l30s. Valleys will radiate out as
winds will quickly decrease and expect lows in the single digits
mts/valleys.
Tomorrow...
Main concern if RED FLAG conditions. Gap flow winds are expected tot
be rather strong tomorrow and RH values will crash. For this reason
have issued a RED FLAG warning for the I-25 corridor from Pueblo
down to the border, and this warning extends eastward out to the KLHX
region. I would not be too surprised if this warning may need to be
expanded by later shifts.
Although it will be windy tomorrow, it will be relatively mild with
60s most of the plains with 50s El Paso. 40s in the SLV with teens
and 20s mtns.
.LONG TERM...(Monday night through Sunday)
Issued at 252 PM MST Sun Feb 26 2023
Good model agreement continues through the extended period with
better handling of the mid week storm. Ahead of this system,
winds and fire weather will be the primary concerns.
Monday night through Tuesday night...zonal westerly flow aloft
will lead to continuous light to moderate snowfall along the
Continental Divide. Several inches of new snow are expected,
especially for areas over the San Juan range and Central
Mountains.
The main concerns will be across the Plains. Enhanced mixing of
strong westerly flow aloft will lead to very windy conditions
across the Eastern Mountains, into the Plains. The strongest winds
are expected mainly along the lee slopes, east into the I-25
corridor. Gusts in excess of 55 mph are likely. Areas of blowing
dust are likely, and will produce areas of low visibility on areas
highways. Strong cross winds on north-south highways will also
cause dangerous travel conditions. In addition to the strong
winds, humidity values are expected to fall to near 15 percent.
This will give us critical fire weather conditions for portions of
the Plains. As far as highlights go, coordinated to Dodge City,
Amarillo and Albuquerque to hold off given the current busy
weather. High wind and fire weather highlights will likely be
issued either this evening as the busy weather settles, or
overnight on the mid shift.
Wednesday and Thursday...the next upper storm system is forecast
to track out of the Great Basin, across the Desert Southwest and
into the southern Texas Panhandle. Expect snow to increase
Wednesday across the Continental Divide, and persist through much
of Thursday. Snow could be heavy at times, especially for the San
Juan Range where southwesterly orographic flow is favored. Current
projections of 10 to 15 inches are possible over the San Juans,
with lesser amounts over the La Garita and Central Mountains.
Across the Plains, model guidance is developing a surface low near
Trinidad, and tracking it southeast. This will produce easterly
wrap around flow across the Plains late Wednesday night into
Thursday morning. Enhanced upslope flow into the southern I-25
corridor, east along the New Mexico border. A period of 6 to 12
hours of moderate snowfall may be possible over this area, with
several inches of snow possible. For areas along Highway 50 and
north, lighter snowfall is expected given the more southern track
of the surface low, and northerly downslope winds off the Palmer
Divide. Generally an inch or less of snow is likely. A few notes
about this storm system and precipitation chances on the Plains. A
slight shift in storm track and mean the difference of how much
and where snow falls. Speed will also play a factor, and the
current projections are pretty fast, which would limit snow
amounts. A slow down would possibly mean more snow. Stay tuned!
Friday through Sunday...another weak system in northwest flow will
track across Colorado on Friday night with a quick burst of snow
possible from the Palmer Divide, southeast across the Plains.
Beyond this system, flat ridging will give way to southwest flow
with periods of light snow possible along the Continental Divide
through the weekend. Mozley
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 252 PM MST Sun Feb 26 2023
Strong gusty winds will continue rest of the afternoon into early
evening, then let up somewhat tonight. Winds will once against become
strong from the west tomorrow by late morning over all the the 3 taf
sites, KPUB, KALS and KCOS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 1 AM MST Monday for COZ074-087-088-094-
099.
High Wind Warning until 9 PM MST this evening for COZ083-086.
Red Flag Warning from noon to 5 PM MST Monday for COZ228>232.
&&
$$
UPDATE...KT
SHORT TERM...HODANISH
LONG TERM...MOZLEY
AVIATION...HODANISH
Area Forecast Discussion
National Weather Service Tulsa OK
609 PM CST Sun Feb 26 2023
...New SHORT TERM...
.SHORT TERM...
(Through tonight )
Issued at 608 PM CST Sun Feb 26 2023
Made a quick update to add a Dense Fog Advisory for far SE OK over
the next several hours. Fog has become more widespread across
eastern OK this evening in the saturated cool air on the north
side of a sharp warm front down near the Red River. Guidance
indicates that far SE OK will see more widespread dense fog for
several more hours and thus an advisory was issued. The fog
elsewhere should be more transient. The forecast for later tonight
was left unchanged. A line of severe storms is expected to sweep
across the region after 9 PM (trended a tad later than earlier
progs). Some significant severe weather is possible, especially
across northeast Oklahoma, with the latest runs of the HRRR
simulating pockets of near 80 mph wind gusts punching into NE OK.
At least marginally severe winds are possible with the squall
line over into northwest Arkansas as well shortly after midnight.
There`s also some indication that gradient winds from the west
will pick up within an hour or two after the squall line and could
reach advisory intensity. Going wind advisory for the region
overnight should cover.
Lacy
&&
.LONG TERM...
(Tomorrow through Sunday)
Issued at 223 PM CST Sun Feb 26 2023
Gusty winds continue Monday with clearing skies and downslope wind
component pushing high temps above the bias correct blended
guidance. A similar warm pattern is in place Tuesday ahead of the
next cold front passing Tuesday night. A chance of rain will
spread across far southern locations Wednesday into Wednesday
night with this frontal boundary.
The next storm system has trended stronger in the latest
deterministic guidance and there is now stronger agreement in the
pattern. If this continues the precip chances for Thursday into
Friday will trend upward area wide. Cold air will be lacking with
this system however some snow potential may develop on the
backside of this system and beneath the cold mid level temps.
These details have time to be determined but the forecast will
trend in this direction.
&&
.AVIATION...
(00Z TAFS)
Issued at 515 PM CST Sun Feb 26 2023
IFR to MVFR conditions prevail this evening in advance of the severe line of
storms expected to impact the areas sites later this evening and overnight.
VFR conditions return late tonight into Monday. However, gusty west winds will
winds will continue.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 62 48 75 41 / 30 100 0 0
FSM 62 47 73 44 / 30 90 0 0
MLC 66 46 74 42 / 30 80 0 0
BVO 61 46 74 35 / 30 100 0 0
FYV 61 49 71 42 / 30 100 0 0
BYV 61 49 71 42 / 40 90 0 0
MKO 62 47 72 42 / 30 80 0 0
MIO 59 49 72 40 / 40 90 0 0
F10 63 48 73 42 / 30 90 0 0
HHW 68 49 73 42 / 20 80 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Wind Advisory until 6 AM CST Monday for OKZ049-053>076.
Dense Fog Advisory until 9 PM CST this evening for OKZ049-053.
AR...Wind Advisory until 6 AM CST Monday for ARZ001-002-010-011-019-
020-029.
&&
$$
SHORT TERM...30
LONG TERM....07
AVIATION...10