Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/23/25
Area Forecast Discussion
National Weather Service Aberdeen SD
646 PM CDT Sat Mar 22 2025
.KEY MESSAGES...
- Winds will increase out of the northwest tonight over central SD
to the James River, and early Sunday morning east of the James
River. Gusts of 35 to 45 mph are expected, with a Wind Advisory
is in effect during much of the daytime hours Sunday.
- 20 to 40 percent chance of rain showers through early Sunday
morning. Generally, accumulations of less than one tenth of an
inch expected.
- Widespread 30 to 50 percent chances of precipitation Monday. This
is expected to be mainly rain, with some isolated instances of a
rain/snow mix over the Leola Hills early Monday morning. Chances
of more than one tenth of an inch of liquid precipitation is 30
percent or less, with the highest chances across north central
South Dakota.
&&
.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 312 PM CDT Sat Mar 22 2025
An upper level shortwave trough will track across the Northern
Plains tonight and Sunday, leaving northwest flow in its wake Sunday
night.
At the surface, a low pressure system will be centered over the
western CWA this evening, then will track eastward to over Minnesota
by Sunday morning. Seeing some echoes across parts of the southern
CWA this afternoon, but temperatures/dew point depressions are 40
degrees or so in those locations, so likely not seeing any
precipitation reach the ground. In association with the upper level
shortwave energy, the rain shower potential will increase tonight
through early Sunday morning on the north and west side of the low
as it tracks eastward. Rainfall amounts at any one location will be
minimal, likely no more than one tenth of an inch. Any rain chances
will come to end by mid morning Sunday as the low moves away from
the region. However, will see a tightened pressure gradient on the
back side of the low on Sunday, with sustained wind speeds of 20 to
35 mph, and gusts of 40 to 45 mph expected through the daytime
hours. Therefore, have issued a Wind Advisory for the entire CWA
Sunday morning through Sunday evening. Will continue to monitor for
elevated grassland fire danger concerns, but right now it looks as
though relative humidity values will stay above criteria. Wind
speeds will die down Sunday night as high pressure drops over the
region.
Low temperatures tonight will be in the upper 20s and lower 30s.
High temperatures on Sunday will range from the lower 40s across
west central Minnesota and far northeastern South Dakota, to the
lower 50s along and west of the Missouri River. Lows Sunday night
will be mainly in the 20s.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 312 PM CDT Sat Mar 22 2025
Clusters are consistent on a +PNA pattern for early next week with
the ridge pushing a bit east by the midweek as a large low will hang
out just off the Pacific Coast. This ridge will continue east and
over the central and northern parts of the country by Thursday, as
Clusters still agree well on the position and intensity. We start to
see Clusters diverge a bit from each other Friday (Day 6) as more of
a -PNA pattern sets up over the CONUS, however, timing, location,
and intensity vary on the incoming trough. Day 7 and onward Clusters
really diverge on the overall pattern. With northwest flow aloft, a
weak low will push southeast over the Northern Plains and Upper
Midwest Monday/Tuesday. GEFS/ENS do show light moisture entering the
northwestern CWA early Monday morning, and spreading east and
southeast over the CWA through the day into the evening. GEFS is a
bit more aggressive on this system than ENS at this point. As this
system pushes southeast, it will weaken. Latest NBM pops have
shifted a big west and chances not as high as the previous run,
ranging from from 30-50% mainly along and west of the Mo River, with
the highest pops over Corson County. Pops spread east/southeast with
the system towards the evening, with pops only around 15-25% over
portions of northern and northeastern SD. Ptype could be a bit of
rain/snow early in the morning, mainly over the Leola Hills, and
changing to rain by mid morning as it warms up. Wetting rain chances
looks to be quite slim as prob of 24 QPF>0.10" is 25-30% over north
central SD. High pressure moves in Tuesday over the western CWA with
still a 15-25% pop chances over the far eastern CWA as this area
will be on the north to northwest side of the low. The high will be
dominant Wednesday and Thursday keeping the area dry. With the
incoming trough for the end of the week, models are locking on to a
low that will sweep across the area ~Friday through Saturday. As
mentioned, it is still too early to nail down specifics at this time
but Ptype looks to be rain then changing to a mix of rain/snow or
all snow on the backside of the system.
Winds do increase behind the early week system Tuesday afternoon,
with gusts between 25-35kts, highest over north central SD, before
diminishing towards the evening. With the ridge to our west then
overhead, we will see a gradual warmup in temperatures each day
through Thursday. Highs will range in the 50s to around 60 Monday,
warming into the 60s to mid 70s by Thursday! Cooler air filters in
with the system starting Saturday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 646 PM CDT Sat Mar 22 2025
Terminals KABR,KATY,KPIR,KMBG
VFR ceilings will continue, with MVFR ceilings moving in from ND
overnight. These ceilings are most likely at MBG/ABR/ATY, and may
only temporarily move across PIR. The main concern will be
increased winds with gusts of 30-40kts late tonight through the
day Sunday. Winds will shift out of the northwest and increase
behind the surface low currently set up near the MO River. Winds
over western SD have already increased, with RAP gusting to 44kts
at 2252Z.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 7 AM CDT /6 AM MDT/ to 7 PM CDT /6 PM MDT/
Sunday for SDZ003>011-015>023-033>037-045-048-051.
Red Flag Warning until 8 PM CDT /7 PM MDT/ this evening for
SDZ033-035>037-045-048-051.
MN...Wind Advisory from 7 AM to 7 PM CDT Sunday for MNZ039-046.
&&
$$
SHORT TERM...Parkin
LONG TERM...MMM
AVIATION...06
Area Forecast Discussion
National Weather Service Burlington VT
1023 PM EDT Sat Mar 22 2025
.SYNOPSIS...
As a cold front exits the region to the southeast, lingering
snow showers, gusty winds, and much cooler air will set in
tonight. Winds subside Sunday with much drier and continued
cooler air as temperatures struggle to get out of the low 30s. A
period of unsettled weather is on tap for the upcoming work
week with a series of fronts bringing rain and snow to the
region on Monday with scattered rain and showers possible
through much of next week.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 1020 PM EDT Saturday...A surface cold front located along
a line between Hartford and Poultney Vermont is exiting the
region to the southeast leaving behind lower clouds and gusty
winds between 25 and 35 mph. Rain showers have switched over to
snow showers across the Adirondacks and northern/central Greens
as dramatically lower temperatures fill in behind the front.
Additional snowfall between a dusting an inch is expected in the
Adirondacks and northern Greens as moisture behind the front
decreases overnight. Temperatures are already in the upper teens
to low 20s in northern New York with temperatures continuing to
fall into the 20s across the entirety of Vermont. Temperatures
tonight will bottom out in the low to mid teens, locally upper
single digits in northern New York and the Adirondacks, with mid
to upper teens across the Champlain Valley and NEK. Clouds are
beginning to clear across the St. Lawrence Valley which should
promote efficient radiative cooling by Sunday morning.
Sunday will be dry and cold with strong cold air advection
behind departing cold front. Winds will be gusty out of the
northwest early in the morning, but die down as surface high
pressure ridging builds over the area. Dewpoints will plummet
in the afternoon and relative humidities will drop towards
critical levels between 20-30% as confidence increases from Hi-
Res models. As the dewpoints drop though, winds will calm down.
This in combination with precipitation from tonight will
hopefully preclude any major fire weather issues. Maximum
temperatures Sunday afternoon will only range through the 30s,
this will feel quite chilly after the recently mild weather.
On Sunday night we will see an increase in clouds as our next
system slides to our northwest out of the Great Lakes
region. Temperatures Sunday night will be in the teens to lower
20s, so as the precipitation to start should fall in the form of
snow. As the system matures Sunday evening, the low will become
centered over its upper-level trough in the Great Lakes Region resulting
in a weakening system overall. Furthermore, based on hi-res NAM
and HRRR guidance, an area of dry air looks to develop across
the northern New York Sunday night which could further limit
the amount of precipitation that falls.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 311 PM EDT Saturday...The active weather pattern
continues as we head into next week, with a surface front
associated with a low over the Great Lakes lifts into the region
Monday morning. A period of snowfall is expected as the front
lifts across, which will likely occur during the Monday morning
commute and make for some slick and snow-covered roads given
antecedent cold weather although conditions should rapidly
improve heading into the afternoon given the higher sun angle
this time of year. Temperatures look to quickly warm across most
of the region, climbing above freezing towards the late morning
and snow transitioning to rain or a rain/snow mix. The
exception to this will be across eastern Vermont, where
temperatures will struggle to warm, holding onto the cold and
snow longer. Total snow accumulations will be light, with just a
dusting across the lower elevations and a few inches above
1500ft elevation or so. Colder air will filter in Monday
evening, bringing additional chances for snow, especially at the
higher elevations.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 311 PM EDT Saturday...Cool and unsettled conditions will
continue for much of the week as an upper level trough settles
over the Northeast. Periods of showers can be expected as a
series of shortwave troughs and troughs push through the region.
Temperatures throughout the week will feel quite springlike and
seasonable, with high temperatures generally in the 40s to near
50 and low temperatures in the 20s and 30s.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Strong cold front moving through Champlain
Vly at 00z with rapidly falling temperatures and strong WNW
winds 15-20G30kts through 06z then NW 12-18G25kts thru 10-12z
then NW10-12G20kts thru 16-18z then NW around 10 kts.
Some light rain showers quickly changing to -SHRASN with FROPA
but reduced vsby to 3 miles likely only across KSLK,KMPV and
KEFK through 03-04z. Mainly VFR but some MVFR with
precipitation. BKN skies becoming SCT before daybreak and mainly
SKC between 12-16z. Outlook...
Sunday Night: VFR. Chance SHSN.
Monday: Mainly MVFR and IFR, with areas VFR possible. Likely RA,
Likely SN, Chance SHRA.
Monday Night: Mainly VFR, with areas MVFR possible. Chance SHRA,
Slight chance SHSN.
Tuesday: Mainly VFR, with areas MVFR possible. Slight chance
SHRA, Slight chance SHSN.
Tuesday Night: Mainly VFR, with areas MVFR possible. Slight
chance SHSN.
Wednesday: Mainly VFR, with areas MVFR possible. Slight chance
SHSN.
Wednesday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Thursday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Danzig
NEAR TERM...Danzig
SHORT TERM...Kremer
LONG TERM...Kremer
AVIATION...SLW
Area Forecast Discussion
National Weather Service State College PA
1048 PM EDT Sat Mar 22 2025
.SYNOPSIS...
Surface high pressure over the Great Lakes will build into
Pennsylvania tonight and Sunday, then a weak wave of low
pressure will track just south of the state Sunday night. An
upper level trough will remain over the area through the middle
of the week, with a possible clipper tracking south of
Pennsylvania Tuesday night.
&&
.NEAR TERM /THROUGH SUNDAY/...
Surface high pressure building in from the Grt Lks will result
in fair weather and diminishing winds overnight. NBM min temps
Sunday AM range from the upper teens over the N Mtns, to the mid
and upper 20s over the Lower Susq Valley, which is 5-10F below
climo.
Fair and seasonable weather with light wind is anticipated
Sunday, as the surface high drifts over the region. Model RH
profiles indicate early sunshine will fade behind increasing
high clouds later in the day ahead of a wave of low pressure
approaching from the Ohio Valley.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Model guidance indicates a weak surface low will pass south of
PA Sunday night. Warm advection precip will spread west to east
across CPA Sunday night. QPF amounts are still projected to be
on the light side between 0.10-0.25 inches. As for ptypes,
model soundings support light rain over most of Central PA.
However, wet snow appears likely over the N Mtns, where a light
snow accum of up to 1 inch is possible.
The surface wave and bulk of the precip should shift east of the
forecast area by 12Z Monday. Subsidence associated with an
arriving dry slot should result in breaking clouds Monday with
deep mixing leading to gusty WSW winds. Bufkit soundings support
afternoon wgusts of 30-35kts, which is considerably higher than
NBM guidance. Mixing down 800mb temps yields expected maxtemps
Monday ranging from around 50F over the NW Mtns, to the low 60s
across the Lower Susq Valley.
High temperatures will be about 10 degree chillier on Tuesday,
although it should be a dry day before a weak clipper system
approaches for Tues night.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Medium range guidance indicates upper level troughing will
remain over the region thru Thu, likely resulting in seasonably
cool and mainly dry conditions. A shortwave rotating through the
base of trough could produce a few rain/snow showers Tue night.
Much of the recent guidance tracks a weak clipper low south of
PA, thus the highest POPs are focused over the southern
counties. The best chance for a light snow accumulation is over
the high terrain of Somerset County.
Confidence in dry weather is fairly high Wed PM through
Thursday, as most guidance indicates surface ridging builds into
PA from the Ohio Valley.
The departure of the upper trough and surface high pressure
passing off of the East Coast will likely result warmer
and mostly dry conditions next Friday and Saturday. However, a
slow-moving warm front lifting through the E Grt Lks could
produce a few showers, mainly over the N Mtns. EPS 2m temp
plumes show a wide spread next Saturday associated with uncertainty
regarding how far north the warm front gets. Based on mean
850mb temps around 10C, any valley locations south of the front
could potentially reach the 70s, while clouds and potential
showers could result in markedly cooler conditions north of the
eventual frontal location.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
High pressure has started to influence central Pennsylvania
which will lead to a sharp decrease in cloud cover over the next
2-3 hours, which is fairly well represented in the bulk of
model guidance. High (~80-90%) confidence in VFR conditions
prevailing VFR at all airfields outside of BFD/JST through 00Z
Monday, as cloud cover has generally eroded and all model
guidance continues to indicate ceilings above 2500ft AGL. At
BFD/JST, there recent model guidance does indicate that lower
ceilings ~2000-3000ft AGL will linger on through at least 01Z
which moderate confidence (~50-60%) on these ceilings lifting
before 01Z. Main alternative solution is that ceilings hold on
slightly longer into the 01-02Z Sunday timeframe; however, lower
confidence (~20%) solution at this time given RAP model
soundings. After 02Z Sunday, high confidence (~80-90%) on VFR
conditions continuing at BFD/JST through 00Z Monday.
Breezy winds will continue overnight with model guidance in
fair agreement on winds slowly decreasing throughout the
overnight period, with high confidence in winds below 10kts ~12Z
Sun. High clouds begin working into central Pennsylvania west-
to-east towards the end of the TAF package; however, some added
moisture as winds shift southeasterly could allow for increasing
clouds across southern airfields (LNS/MDT, mainly). The best
chances based on a consensus of GLAMP/HREF/RAP model guidance
for sub- VFR conditions comes after 00Z Monday.
Outlook...
Sun Night...Chc for rain increases Sun night. Snow may mix in
at onset in the colder spots. Restrictions possible.
Mon...Rain with restrictions possible. Mixing with snow
possible across the north and west as precip tapers to showers.
Tue...Restrictions possible especially N/W with slight chc for
lingering rain and snow showers.
Wed...Restrictions possible especially N/W with slight chc of
rain and snow showers.
Thu...VFR with mainly dry conditions.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Fitzgerald
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Evanego
LONG TERM...Fitzgerald/Bauco
AVIATION...NPB
Area Forecast Discussion
National Weather Service Dodge City KS
514 PM CDT Sat Mar 22 2025
.KEY MESSAGES...
- Warming trend continues today, with afternoon highs in the
upper 60s to mid 70s.
- Cold front passes through southwest KS tonight, but with
little fanfare other than breezy north-northwest winds.
- Dry conditions and above normal temperatures will persist
through the forecast period.
&&
.DISCUSSION...
Issued at 200 PM CDT Sat Mar 22 2025
Water vapor satellite imagery and RAP upper air analysis at
midday reveals nearly zonal flow is in place above the central
plains, with a vorticity max digging southeastward from the
northern Intermountain West into the northern/central plains.
Ahead of this feature, a lee cyclone centered over western SD
continues to deepen, which is resulting in elevated southerly
winds across southwest KS with gusts in the 30-35 mph range.
However, these winds will begin to weaken by mid-afternoon as a
secondary lee cyclone develops in southeastern CO and diminishes
the pressure gradient across our area. As this happens, winds
will begin to acquire a slight westerly component, and this
newfound downsloping trajectory will foster afternoon highs
ranging from the mid 70s southwest to the upper 60s northeast.
Overnight, the aforementioned vorticity max will eject onto the
northern/central plains, sending a modest but dry cold front
through southwest KS. Northerly winds will increase in its wake,
and lows will drop into the low/mid 30s northwest to the mid 40s
southeast.
Sunday morning, northerly winds in the wake of the cold front
will be fairly strong, sustained in the 15-25 mph range gusting
up to 35 mph, but will gradually weaken throughout the day as
weak surface high pressure builds into the area. Nevertheless,
cold advection will promote much cooler temperatures Sunday
afternoon, with afternoon highs in the low to mid 60s. Early
next work week, medium range ensembles agree upper level ridging
will build across the western CONUS, and take its sweet time
moving eastward. This synoptic pattern will facilitate a
continuation of the warm and dry conditions across the central
plains.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 513 PM CDT Sat Mar 22 2025
The only impacts to aviation will be winds this period. Gusty
southerly winds in the very late afternoon will cease gusting as
we approach sunset or 01z. And then about 6-8 hours of weaker
winds under 12 knots before momentum transfer returns with
northwest winds the next cold front bringing sustained speeds of
about 22 - 24 knots and gusts commonly 30 - 34 knots after about
07 or 8z (2 or 3 AM). The gusty winds should wane in the
afternoon, but still be gusting to around 25 knots through 23z.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Springer
AVIATION...Russell
Area Forecast Discussion
National Weather Service Grand Rapids MI
722 PM EDT Sat Mar 22 2025
.KEY MESSAGES...
- Rain, Snow, Wind Sunday to Monday
- Cooler Until More Active Weather Late Next Week
&&
.DISCUSSION...
Issued at 345 PM EDT Sat Mar 22 2025
- Rain, Snow, Wind Sunday to Monday
Strong warm advection Sunday in advance of an approaching,
digging upper trough causes widespread precipitation to break out
by late in the day-- once a lingering dry air mass is overcome.
The arrival of the precip at the warmest part of the day when sfc
temps are expected to be in the upper 40s supports all rain as
p-type as it begins but sfc dew point temperatures in the 20s and
evaporative cooling could result in some snow mixing in across
the higher elevations north of Interstate 96.
Some impacts from snow may occur near and north of Big Rapids
later Sunday night into Monday morning once the cold air with
this system rushes in. The sfc low is shown to deepen while moving
from nrn WI to the Straits of Mackinac, with H8 air around -9C
pouring in. As the upper low closes off over Lake Superior, the
system comma head will become better defined and drop south into
the NW CWFA. This combined with some lake enhancement will create
some accumulations, particularly in the higher elevations near
and north of Big Rapids where up to 4" of wet snow is possible.
Roads could be slick for the Monday morning commute.
Snow showers are expected over the rest of the area too late
Sunday night and Monday although slightly milder sfc temps and
less QPF should limit accumulations/impact potential south of Big
Rapids.
Gusty west winds will also accompany this system late Sunday
night and Monday, with fcst soundings and HRRR guidance suggesting
gusts of 40-45 mph in the tight pressure gradient on the south
side of the deep sfc low. A period of gales is possible on Lake
Michigan.
- Cooler Until More Active Weather Late Next Week
Upper trough remains anchored over the GrtLks region through mid
week and below normal temps will continue before height rises
and warm advection occur later in the week. We could see another
flare up of rain and/or snow showers occur later tuesday into
Tuesday night with a secondary shortwave and sfc trough/front
dropping through the northwest flow.
High temps should be back up near 60 by next Friday and possibly
even 70 by Saturday, although spread is fairly large in both
temps and QPF by that time.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 718 PM EDT Sat Mar 22 2025
High clouds are expected through 15z or so, then a gradual
decrease in ceilings as a cold front approaches. Southeast winds
will increase after sunrise and be gusty as the front approaches.
Rain will move in from the southwest after 20z and cigs will fall
to at least MVFR and perhaps IFR around 00z.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Meade
AVIATION...04
Area Forecast Discussion
National Weather Service Houston/Galveston TX
318 PM CDT Sat Mar 22 2025
...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE...
.SYNOPSIS...
Issued at 238 PM CDT Sat Mar 22 2025
This weekend finds us in advance of a cold front set to come
through late tomorrow night into Monday morning. The emphasis here
is very much on "front", and not at all on "cold". As we look at
the rest of the weekend and a new week ahead, here are the key
points on the forecast:
- There will be some shower and thunderstorm potential both ahead
of the front on Sunday afternoon and along the front Sunday
night into Monday morning. This activity is not expected to be
widespread thanks to a strong cap in place, but a strong to
severe storm or two is on the table north of the Houston metro,
if a storm can really burst through that cap.
- Little to no colder air makes its way into the area as onshore
flow returns almost immediately after the front passes. Look for
highs in the 80s to persist deep into next week.
- The early part of the new week will feature fair weather, but
unsettled weather is expected to return in the back half of the
week. Look to Thursday and Friday for the next solid chance of
rain and thunderstorms.
&&
.SHORT TERM...
(This evening through Sunday Night)
Issued at 238 PM CDT Sat Mar 22 2025
We`ve got ourselves a classic onshore flow setup this afternoon,
with high pressure in place over the northeastern Gulf, while a
low pressure center develops in the lee of the Colorado Rockies.
Between those clowns and jokers, we are stuck with the increasing
humidity from winds right off the Gulf. Another sign of the
deepening moisture pool? You can see on a satellite image, or
above your head if you`re outside - or, if you`ve got a phone and
are outside, you can see on both at the same time! - cloud streets
streaming inland from the coast.
Another result of the increasingly humid airmass will show up
tonight, in considerably warmer temperatures. Any crispness from
last night will be gone, and the cold overnight lows of two nights
ago is a distant memory. Instead, we`ll be experiencing lows that
get snagged somewhere in the 60s. At the Gulf coast, expect
mid-60s, which really is only about 5 degrees above average. Way
up around Crockett, lows in the lower 60s will be about as close
to average high temps as they are to average low temps! On top of
that, we may be looking at some fog potential. This may be
disrupted by winds staying around or above 5 mph through the
night, however. This may move the focus for fog to the coastal
waters for some patchy sea fog - more on that in the marine
section below.
Starting from the higher floor of temperatures, we`ll keep on
warming right through Sunday. Take today, tack about 5 degrees on,
and that`ll give you a pretty good expectation for tomorrow. Will
that boost in heat and humidity give us enough to spark some
afternoon showers and storms? Wellllll, don`t get too excited for
anything like that. We have got some real solid capping in place,
and it`ll be tough to be able to overcome that from daytime
heating. The best potential for that looks to be east of Houston,
from the Trinity Valley eastward out of our forecast area.
But...the HREF joint probability for getting CAPE above 500 J/Kg
and CINH below 25 J/Kg kind of implies tomorrow could be a bit
more active than deterministic CAMs indicate. But ultimately, the
best potential is probably going to come Sunday night with the
front. It`s certainly not an impressive front, so even here I`d
expect nothing more than a broken line of showers and storms. And
if the HRRR is right, maybe it`ll just be a smattering of
sprinkles and light showers?
&&
.LONG TERM...
(Monday through next Friday)
Issued at 238 PM CDT Sat Mar 22 2025
Heading into Monday, global models continue to indicate the stalled
progression of the cold front along the immediate coast, with
scattered showers along the boundary lingering as late as early
Monday afternoon. That being said, the prospect for any significant
rainfall and/or strong thunderstorms will not be on the table by
this point. Lingering precipitation should clear out of the area as
surface high pressure establishes itself over the Southern Plains,
giving us a short lived period of offshore flow/dry advection before
its eastward trajectory reestablishes an onshore regime during the
overnight period. Highs on Monday are expected to reach the low to
mid 80s for most of the area, though some variation based on the
exact timing and extent of lingering showers is possible.
Steady onshore flow through midweek will result in a period of warm
and humid but otherwise uneventful weather with high pressure
generally remaining in place over the Southeastern CONUS. Through
Wednesday, look for highs in the mid to upper 80s and overnight lows
generally in the 60s. Increasing surface dew points, while not at
the point where this could be considered a summer-like pattern just
yet, will being a noticeably humid feeling when stepping outdoors
as southerly winds increase moisture transport off the Gulf.
Our next period of active weather looks to arrive on Thursday as a
robust midlevel trough approaches from the Baja California region,
providing a source of enhanced lift that will invigorate widespread
showers and thunderstorms across SE TX on Thursday night and Friday.
Right now, this doesn`t present an immediate flash flooding or
severe weather threat, but still warrants monitoring as the
environment continues to indicate the potential for some locally
heavy rain. Given increasing cloud cover and rainfall, highs on
Thursday and Friday should remain confined to the upper 70s/low
80s.
&&
.AVIATION...
(18Z TAF Issuance)
Issued at 1218 PM CDT Sat Mar 22 2025
Going into the afternoon, starting to see the development of
southerly winds 10-15 G20-25 along with cloud streets on the edge
of SCT/BKN at 035-050 for most terminals (GLS on the coast is
still nearly SKC). Expecting this through sundown, at which point
gusts should drop off and while cloud cover should decrease
briefly, cloud bases will come down, and eventually get ourselves
an MVFR CIG around or shortly after 05Z.
In the extended at IAH, we are getting close to having to deal
with SHRA or even TSRA mentions. If strong cap breaks, could see
isolated to scattered SHRA/TSRA 19-22Z, but thinking this will
mainly be safely east of the airport and held off on even a
PROB30 mention at this point. Future cycles can re-evaluate this,
and will eventually have to deal with incoming front as well.
&&
.MARINE...
Issued at 238 PM CDT Sat Mar 22 2025
Onshore flow will remain in place through the end of the weekend,
with a brief period of easterly winds arriving as a weak cold front
approaches the coast early on Monday. This boundary will also bring
with it scattered showers and storms, though severe storms are not
expected along the coast/offshore. Onshore flow returns later on
Monday, and should remain below caution thresholds through mid-week.
A storm system will move into the area later on Thursday, bringing
our next chance of widespread showers and storms that will persist
into Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 64 85 63 84 / 0 10 40 10
Houston (IAH) 65 83 67 85 / 10 30 40 30
Galveston (GLS) 67 78 67 75 / 10 20 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...Luchs
LONG TERM....Cady
AVIATION...Luchs
MARINE...Cady
Area Forecast Discussion
National Weather Service Huntsville AL
831 PM CDT Sat Mar 22 2025
...New NEAR TERM, SHORT TERM, LONG TERM...
.NEAR TERM...
(Tonight)
Issued at 831 PM CDT Sat Mar 22 2025
Surface high pressure to our south will promote clear skies and
light winds tonight across the TN Valley. This will allow temps to
drop into the high 30s and low 40s. Despite the cooler temps frost
is not anticipated due to the lingering dry air. Over the course
of the night the surface high pressure to our south will translate
east over the Florida Peninsula. In response, winds will veer to
the south by daybreak.
&&
.SHORT TERM...
(Sunday through Wednesday)
Issued at 831 PM CDT Sat Mar 22 2025
Throughout the day on Sunday mid level troughing will push through
the Great Lakes Region. At the surface, this will translate to a
low pressure system and associated cold front pushing across the
eastern CONUS. The constricting pressure gradient will increase
southerly winds throughout the day with gusts of 25-30 MPH
forecast. The strong southerly flow will advect in warm, moist
air from the Gulf allowing temps to rise into the mid 70s with dew
points reaching the 50s.
The passage of the cold front Sunday evening will provide enough
lift to support rain and storm chances. The environment will be
supportive of some strong to severe storms with with CAMs
indicating 50-60 KTS of bulk shear and 500-1000 J/KG of CAPE. Storms
look to enter NW AL between 6-7 PM as multicell clusters with the
potential to become more linear as they push east. Main hazards
look to be damaging winds, hail, and a low chance for a tornado.
The HRRR continues to support a higher end scenario where we
remain surfaced based areawide through a majority of the event
with SBCAPE values above 500 J/KG. This would increase our severe
threat and favor the potential for embedded supercells. Most other
CAMs show NW AL being surfaced based and storms quickly becoming
elevated as they move east. This seems like the most likely
scenario however we will keep an eye on model trends over the next
24 hours. For now, our highest confidence in seeing severe storms
remains in NW AL.
Storms will be exiting the area around sunrise however NW flow
aloft looks to remain through the duration of the short term
forecast. Without any dominant surface features the start of the
work week will feature rather benign weather as temps warm into
the 60s and 70s each day.
&&
.LONG TERM...
(Wednesday night through Saturday)
Issued at 831 PM CDT Sat Mar 22 2025
A broad upper trough across the Great Lakes will bring a cold front
south through the area on Wednesday morning. This will not bring
precipitation. Temperatures will reach the upper 60s to lower 70s for
highs Wed and Thu with lows in the upper 30s to lower 40s. The
surface and 850 mb highs will shift off the coast of the Carolinas
by Friday allowing a southerly flow to develop. Temperatures will
warm well into the 70s Friday and Saturday with lows in the 50s to
around 60. An upper low/trough in northern Mexico will be pivoted
northeast thru Texas and the lower MS Valley Saturday into Saturday
night as additional shortwaves cross the central Rockies into the
central Plains. Timing differences still could play a role in the
arrival of showers and thunderstorms with this system, but for now
keep suggested blended guidance with generally low chances (30-40%)
Saturday into Saturday night.
&&
.AVIATION...
(00Z TAFS)
Issued at 420 PM CDT Sat Mar 22 2025
VFR flight weather conditions are forecast. Light and variable
wind through tonight will become south-southwest with gusts over
25kt expected by 17-18Z. A band of SHRA and TSRA will enter far
northwest AL at the very end of the period (~23-00Z), but should
remain northwest of KMSL through that time.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...RAD
SHORT TERM....RAD
LONG TERM....17
AVIATION...17
Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
600 PM CDT Sat Mar 22 2025
.KEY MESSAGES...
- Showers and a few thunderstorms will develop late tonight
through Sunday afternoon. Storm total rainfall will range from
0.25 to 0.50 across much of central Illinois...with higher
amounts in excess of 0.50 focused along/south of I-70.
- Seasonable temperatures will be observed for the next several
days before readings surge well above normal by the end of next
week.
&&
.SHORT TERM...(Tonight through Sunday)
Issued at 244 PM CDT Sat Mar 22 2025
A short-wave trough evident on 19z/2pm water vapor imagery over
the Northern Rockies will track eastward over the next 24 hours,
pushing a weak cold front into central Illinois on Sunday. As the
nocturnal LLJ increases well ahead of the system, WAA will lead to
the development of showers along a trailing warm front across
Missouri and southern Illinois tonight. The showers will gradually
spread northward into the southern KILX CWA well after midnight,
but may not arrive along the I-74 corridor until after dawn
Sunday. Instability will initially be quite paltry: however, the
HRRR shows MUCAPEs of 200-400J/kg along/west of I-55
late...supporting isolated thunder mention toward daybreak.
Showers will overspread the entire area Sunday morning, then will
mostly shift eastward into Indiana by afternoon. While the primary
area of rain will be long gone, the approach of the upper short-
wave will provide enough lift to trigger scattered showers/thunder
even into the afternoon. Once the wave departs, any showers will
come to an end and dry conditions will return by Sunday evening.
Storm total rainfall will mostly range from 0.25 to 0.50, but will
approach 1 inch in a few spots south of I-70 where showers will
be most persistent into the afternoon. Given the extensive cloud
cover and showers, the NBM guidance is way too warm for highs on
Sunday, so have undercut those numbers considerably...resulting in
highs mostly in the lower to middle 50s.
Barnes
.LONG TERM...(Monday through Next Saturday)
Issued at 244 PM CDT Sat Mar 22 2025
Zonal flow will dominate the CONUS for the next several days
before a deep upper low comes onshore along the West Coast and
induces downstream ridging across the Plains/Midwest by the end of
the week. Temperatures will therefore remain near normal for this
time of year before readings surge well above normal into the 70s
by Friday/Saturday. While minor rain chances will develop Monday
night into Tuesday, the more significant rainfall will hold off
until Thursday/Friday as the upper ridge and a corresponding warm
front push eastward into the region.
Barnes
&&
.AVIATION... (For the 00z TAFs through 00z Sunday Evening)
Issued at 600 PM CDT Sat Mar 22 2025
Light/variable winds this evening will increase from the
southeast overnight as low pressure moves into the upper Midwest.
As this system approaches, ceilings are forecast to lower to IFR,
with MVFR visibility in -RA, from the southwest Sunday morning.
These conditions will likely continue into mid afternoon before
-RA and low clouds break up. Winds to gradually veer west by late
afternoon, 25-30 kt gusts common through the day.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
643 PM CDT Sat Mar 22 2025
.KEY MESSAGES...
- Blustery southeast winds of 35 to 45 mph tomorrow morning will
turn westerly tomorrow evening and continue through Monday
morning. A few gusts in excess of 45 mph cannot be ruled out.
- Showers will pass through the region tomorrow morning through
afternoon. A few showers may produce wind gusts in excess of
45 mph, particularly during the afternoon.
- Monday morning will feel cold with wind chills in the teens.
- A trend toward warmer temperatures, but also chances for
rain, will commence toward the end of the week.
&&
.DISCUSSION...
Issued at 228 PM CDT Sat Mar 22 2025
Through Wednesday:
Regional water vapor imagery augmented by RAP mesoanalysis data
shows short-wavelength upper-level ridging sliding into the Upper
Mississippi River Valley. Meanwhile, surface observations
depict a surface pressure ridge sliding into the Great Lakes.
The net result is a cool, but otherwise pleasant, mid-March
afternoon with mostly sunny skies and light winds. As the
surface pressure ridge slides eastward overnight, continued
light winds and clear skies will set the stage for a chilly
night with overnight lows in the low to mid 30s.
Tomorrow, the vigorous upper-level shortwave trough currently
evident over Montana will dive southeastward into the Great
Lakes accompanied by a sub-1000mb surface low moving eastward
into upper Lower Michgian. Increasing WAA ahead of the low
should allow for showers to blossom across the region tomorrow
morning through early afternoon, though an initial wedge of dry
air may delay the onset of precipitation reaching the ground
until late morning. In fact, forecast soundings depict some
45-50kt of flow dipping as low as 2500 to 3000ft AGL, which if
dry air is more prevalent, may attempt to mix to the surface
from mid-morning to early afternoon. For now, gently nudged
forecast winds and gusts upward to the 35 to 40 mph range. With
that said, it would not be surprising if winds end up
overperforming during daylight hours tomorrow with a few gusts
tagging 45 mph. This is especially true during the late
afternoon as a narrow ribbon of 0-3km CAPE >200 J/kg ahead of
the cold front may allow for a few low-topped showers, which may
efficiently mix stronger winds downward.
Tomorrow night, the surface low is expected to stall near the
Mackinac Straights and may even deepen further toward the lower
990 mb range. With a west-to-eastward oriented isallobaric
gradient over the Lower Great Lakes (peak pressure falls over
Lower Michigan), westerly winds behind the cold front may
steadily increase throughout the night and increase further
after daybreak Monday, with peak gusts of 35 to 45 mph appearing
increasingly probable. As a result, tomorrow night through at
least Monday morning looks blustery and chilly with wind chills
falling into the teens. Winds will be gradual to ease throughout
the day on Monday, which will make the highs in the the upper
40s to lower 50s feel a touch cooler.
Tuesday should offer a brief break in the action as the surface
pressure gradient relaxes and the back edge of upper-level
cyclonic flow shifts eastward toward southern Ontario. A low-
amplitude upper-level shortwave may ripple through the area
during the afternoon and evening, which should at a minimum lead
to increasing clouds but may also support a few showers across
the area. Ensemble model guidance is spread on exactly when and
where the low-amplitude feature will track, so for now, will
maintain broad chance wording (30 to 40% PoPs) centered on the
Tuesday night through early Wednesday timeframe.
Thursday Onward:
Toward the end of next week, ensemble model guidance shows a
strong signal for rapidly building upper-level heights ahead of
a strong storm system stalling near the Pacific Northwest.
Ensemble 850mb temperature distributions are remarkably narrow
by the Friday to Saturday timeframe near +10C or so, which
should translate to highs climbing to the upper 60s if not lower
70s. At the same time, additional incoming/merging Pacific
storms may cause at least partial upper-level shortwave
"shedding" into the central US, which should encourage the
development of a storm system or two in the general region at
some point next weekend. With that in mind, the general idea is
that both temperatures, as well as chances for rain, will
increase toward the end of next week. Conceptually, would have
to think there may be a brief period of cooler temperatures
toward the very end of the month as well behind whatever storm
system(s) develop next weekend.
Looking well ahead, ensemble model guidance exhibits an
emerging signal for a substantial warm-up during the first week
of April ahead of what may be a series of spring storm systems.
The EPS is by far the most aggressive with such a signal with
mean MUCAPE increasing >500 J/kg. As a result, the first week of
April may emerge as a timeframe to watch for a threat for
severe weather somewhere within the broad Midwestern region.
Borchardt
&&
.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 643 PM CDT Sat Mar 22 2025
Key Messages:
- Short window for LLWS at RFD early Sunday morning.
- Widespread rain moves in Sunday morning into the afternoon
with associated CIG/VSBY reductions to IFR/MVFR, ending with a
narrow band of gusty showers.
- Strong SSE winds gusting to 30-35kt develop Sunday morning,
trending S to SSW in the afternoon then turning W and
increasing >35 kt Sunday evening.
Winds will continue to ease this evening, eventually settling
into a light SE direction overnight as high clouds increase in
coverage ahead of our next weather system. A brief window for
LLWS will be possible during the pre-dawn hours Sunday toward
RFD as a 45-50kt low-level jet moves overhead prior to surface
gusts developing.
Widespread rain will then lift into the area Sunday morning, by
13-14Z at RFD and 15-16Z at the Chicago area terminals. Expect
steadily decreasing CIGS and VSBYS through the morning, with IFR
CIGS and MVFR VSBYS in steady rain expected by early afternoon.
On the back edge of the rain a broken line of gusty convective
showers is expected to move through. The thunder threat
continues to look low (<15% chance).
Winds are also expected to quickly increase Sunday morning once
mixing commences, with gusts in the 30-35kt range expected
through the day, beginning out of a SSE direction then gradually
veering SSW in the afternoon (during the 19-21Z timeframe).
Winds then turn westerly and increase behind a cold front and
aforementioned gusty showers late afternoon/early evening. Wind
gusts in excess of 35 kt are likely during this time, with 40+
kt gusts possible.
Petr
&&
.MARINE...
Issued at 228 PM CDT Sat Mar 22 2025
A deepening low pressure system is expected to move through the
Upper Great Lakes tomorrow afternoon and stall near the Mackinaw
Straights tomorrow night. As the system nears, southeasterly
winds will increase tomorrow morning with frequent gusts up to
30 kt and a few gale force gusts to 35 kt. Tomorrow afternoon, a
cold front will sweep across the region causing winds to turn
westerly and increase to gales in excess of 35 kt. Gale force
winds should continue through mid-Monday morning before easing
by Monday evening.
A Gale Watch is in effect for the Illinois and northwestern
Indiana nearshore waters from tomorrow afternoon through Monday
morning.
Borchardt
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Gale Watch from Sunday afternoon through Monday morning for
the IL and IN nearshore waters.
Small Craft Advisory until 7 PM CDT this evening for the IN
nearshore waters.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Springfield MO
606 PM CDT Sat Mar 22 2025
.KEY MESSAGES...
- Showers and a few thunderstorms likely (50-90%) tonight into
Sunday morning. There is a slight chance (15%) for a few
isolated strong to severe thunderstorms capable of producing
large hail (up to the size of golf balls), especially west of
Highway 95 and south of Highway 32.
- Drier and above normal temperatures late this weekend into
early next week with daily elevated fire danger through
Tuesday.
- Next system to move through sometime late next week into the
weekend bringing 30-60% rain and thunderstorm chances. There
is a good deal of uncertainty in the timing of this system.
&&
.SHORT TERM /THROUGH SUNDAY/...
Issued at 245 PM CDT Sat Mar 22 2025
Current water vapor imagery depicts a shortwave trough diving
into the northern Plains. A subtle, smaller shortwave can be
noted ejecting off the Rockies over the central Plains. This is
better noted in RAP analysis, especially at 700 and 850 mb. This
will be the main weather maker for us tonight. In the meantime,
mostly clear skies is on track to lead to highs in the middle
to upper 60s. Lower 20s dewpoints currently in place are leading
to observed relative humidities below 25%. The good news is that
southerly winds have calmed down a bit in the 8-12 mph range.
Nevertheless, elevated fire risk is still present for the rest
of the afternoon thanks to the dry air in place.
Slight (2 of 5) Risk for severe thunderstorms tonight:
As the very subtle shortwave traverses over our region,
southerly winds will increase and surge near-surface moisture
northward. At the same time, stronger westerly winds within the
shortwave will advect an elevated mixed layer--characterized by
7-8 C/km mid-level lapse rates--overtop the moisture. and
create enough elevated instability for thunderstorms to develop.
The increased low-level southerly flow will strengthen a low-
level jet across east OK and west AR to 35-45 kts. The nose of
the jet will edge into the corners of MO/AR/OK. This is where
thunderstorms are expected to develop, where warm air advection
and convergence is maximized. The timing of this looks to be
around the 6-9 PM timeframe. The storms will then overspread SW
MO through the rest of the evening and into the overnight hours.
A few of these storms will have the potential to become strong
to severe as effective shear will be 50-60 kts which is more
than enough for supercells. Given somewhat weaker surface
moisture and a nocturnal inversion, these storms will likely be
elevated. Shear profiles above the inflow layer consist of
mostly straight hodographs with even some slight backward
curvature. This, along with the steep mid-level lapse rates,
will pose the risk large hail up to the size of golf balls.
HREF soundings and updraft helicity swaths continue to point to
the potential for splitting and left-moving supercells. These
generally have a higher hail risk, so we can`t rule out larger
stones, but with skinny CAPE profiles, we expect much of the
hail to be on the smaller end (up to quarters to golf balls).
Additionally, the best chance for these storms looks to be along
and south of Highway 60 where 1-3 km helicity values are much
higher. As you go north of the highway, winds become static
within the 2-6 km layer, further decreasing the severe hail
threat.
There is a very conditional scenario for a very low-end tornado
threat in the extreme SW corner of MO (2% chance). This
scenario is dependent on if moisture return is greater and
quicker than most models forecast. This would bring the chance
for storms in extreme SW MO to become surface based and tap into
strong low-level shear to pose a tornado risk. CAM verification
maps, however, are showing moisture return to be happening
slower than predicted, so at the moment, this scenario has an
even lower chance of panning out.
Lastly, redevelopment of thunderstorms is possible as a cold
front moves through early Sunday morning in the 5 to 11 AM
timeframe. The chance and confidence on this is lower due to a
capping inversion likely in place, though there is still a
30-50% chance of scattered showers and thunderstorms occuring
during this time.
Dry conditions to follow the storm system:
After the cold front passes, high temperatures will be slightly
cooler in the lower to middle 60s with dry air and 15-20 mph
NW`ly winds. This will continue to pose an elevated fire weather
risk, though cooler temperatures should keep RHs above 25% for
much of the area.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 245 PM CDT Sat Mar 22 2025
Drier and above normal temperatures through mid next week:
The longwave pattern will stall with a trough over the NE CONUS
and a ridge across the west CONUS for much of next week. This
will place our area on the western fringes of a northwesterly
jet. This will allow warmer temperatures to slowly filter into
the region, though dry air will still be in place through at
least Tuesday (see the Fire Weather section below for more
details). Highs will be in the middle to lower 70s Monday and
Wednesday, in the lower to middle 70s Tuesday and Thursday, and
in the middle to upper 70s Friday into next weekend. Lows look
to stay steady in the 40s through Wednesday night before
increasing into the 50s Thursday night into the weekend.
The Extreme Forecast Index is showing some signal for well above
normal temperatures Friday and Saturday. NBM spreads tend to
agree with the 75th percentile in the middle to upper 80s while
the current forecast is in the middle to upper 70s. Therefore,
there is a 25% chance that we could see high temperatures
greater than the middle to upper 80s come next week. This will
mainly be determined by how strong the upper-level ridge gets as
it moves across our area. The GEFS has a much warmer solution
than the EPS and GEPS (which falls in line with known model
biases).
30-60% chance of rain and thunderstorms late next week:
Within the large-scale ridge translating over our region, a
weak shortwave is progged to slip underneath the apex of the
ridge. If this occurs, the energy within the shortwave would be
able to tap into the warmer and moist conditions building under
the ridge, bringing multiple chances for rain and thunderstorms
Thursday into the weekend (30-60% chance). There is still a
great deal of uncertainty in timing and intensity of the ridge
and subsequent shortwave, so details cannot be gleaned, but it
could be a nice relief from the dry conditions early this week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 603 PM CDT Sat Mar 22 2025
VFR conditions will prevail until around 03z when an area of
thunderstorms will likely develop near the sites. This
thunderstorm threat will last for a few hours with a few severe
storms with large hail. Another round of showers and
thunderstorms could move through SGF around 08-10z however
confidence is lower with that second round. Surface winds will
be out of the southeast with a gradual change to the southwest
and then west Sunday morning. Ceilings will likely drop close to
MVFR Sunday morning before clearing. Lastly, low level wind
shear is likely at SGF and JLN tonight.
&&
.FIRE WEATHER...
Issued at 245 PM CDT Sat Mar 22 2025
Areas of elevated fire danger linger through early next week.
Below are some fire weather parameters through Tuesday:
Monday:
High Temperatures: 62-70 F
Minimum Relative Humidity: 15-30%
Sustained Winds: W 8-12 mph
Wind Gusts: 10-20 mph
Tuesday:
High Temperatures: 71-77 F
Minimum Relative Humidity: 20-35%
Sustained Winds: NW 10-15 mph
Wind Gusts: 20-25 mph
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.
&&
$$
SHORT TERM...Price
LONG TERM...Price
AVIATION...Burchfield
FIRE WEATHER...Price
Area Forecast Discussion
National Weather Service Sacramento CA
153 PM PDT Sat Mar 22 2025
.SYNOPSIS...
Chances for light showers (mainly over the mountains) will
continue through this evening. Otherwise, warm and mostly dry
weather is expected this weekend and into next week. Active
weather returns by mid to late next week with breezy southerly
winds.
&&
.DISCUSSION...
A weak disturbance is passing by to the north, with northwest flow
bringing in some moisture. The main impact across the area is
cloud cover, though some very light showers have been observed at
a few spots in the northern mountains. The HRRR model shows a few
isolated showers also spreading into the northern Sierra this
afternoon and evening, but rainfall amounts look limited to a few
hundredths of an inch. The cloud cover has kept temperatures
relatively cool, with highs on track to be about 1 to 4 degrees
below normal. There will be a big change coming, though, as
upper-level ridging builds over Northern California by Sunday and
continuing into early next week. Temperatures will be 10 to 20
degrees above normal (Sun-Tues) with widespread Minor HeatRisk
across the Valley on Monday and Tuesday. Valley temperatures are
forecast to be in the mid to upper 70s and low 80s on Sunday, with
highs in the low 80s on Monday. The National Blend of Models
continues to project Tuesday to be the warmest day of the week
with a 75 to 95% chance of high temperatures greater than 80
degrees across the Valley.
Northerly winds will be breezy at times on Sunday with gusts 15 to
25 mph along the I-5 corridor in the Sacramento Valley.
&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...
Temperatures will begin to cool down by Wednesday, but there
remains quite a bit of uncertainty remaining on how much. This is
due continuing differences on the speed of the ridge exiting to
the east, with a cool upper low approaching. As a result the
spread of possible NBM high temperatures is unusually wide for
Wednesday and also into Thursday, depending if the upper-level
ridge lingers a bit longer. Probabilities of 80 degrees or higher
are between 20 and 60% across the Central Valley, highest over the
northern/central Sacramento Valley and the northern San Joaquin
Valley. The current NBM projects Wednesday highs in the low 70s to
around 80 for the Valley and Delta. Thursday into Saturday highs
will be a several degrees below normal again, with good confidence
in a shortwave trough moving through.
The Ensemble Forecast Index (EFI) continues to highlight elevated
values of Convective Available Potential Energy (CAPE) on
Wednesday late afternoon and evening across the entire Valley,
suggesting unusually unstable conditions for this time of year. A
weak trough located off the coast of Central California may allow
for moisture advection from the south which would aid in creating
a conducive environment for thunderstorm development. The NBM has
trended a little higher in thunderstorm probability, but generally
this is around 15-20% and remains limited to Shasta and Tehama
counties, with less than a 10% chance elsewhere in the Valley.
This will be watched closely to see if the threat expands further.
The Wednesday through early Friday system will bring chances for
light, low-impact precipitation mainly over the mountains.
Forecast amounts have changed little, between 0.25 and 0.60
inches over the Sierra, up to an inch over the mountains of Shasta
County. The Valley could see a few hundredths of an inch around
Sacramento up to a third of an inch for Redding. There is still
some uncertainty regarding exact amounts based on the trajectory
of this system. This will be a fairly warm system as well, with
snow levels starting above 8000 feet on Wednesday before lowering
to around 5000 feet by Thursday. This will allow for a light
dusting of snow with up to an inch or two along higher terrain.
Little to no impacts are expected at this time. Gusty southerly
winds are also expected with this system on Wednesday and
Thursday. Forecast gusts are between 20 and 30 mph through the
Valley with up to 45 mph over the Sierra and northeast foothills.
More unsettled and potentially wetter weather arrives for the
weekend, but strength and timing are uncertain at this point.
&&
.AVIATION...
VFR conditions expected to continue over the next 24 hours. Light
north winds are anticipated through the Sacramento Valley today,
but north winds near or around 12 kts with gusts to 15 kts
expected across the northern San Joaquin Valley until 07Z Sunday.
Periodic gusts up to 20 kts over the Sierra through 20Z Sunday.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$