Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/17/24
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
819 PM CDT Sat Mar 16 2024
.KEY MESSAGES...
- Light snow showers (15-20%) possible east of the Missouri River
tonight through Sunday morning. No accumulations expected.
- Temperatures bottom out Sunday with highs only in the upper 20s to
the mid 30s.
- Warm dry southwest winds on Monday will create elevated fire
danger concerns.
- Mainly dry through Wednesday with above average temperatures.
Increasing precipitation chances Thu-Sat with near average
temperatures.
&&
.UPDATE...
Issued at 817 PM CDT Sat Mar 16 2024
Conditions have improved enough to allow the Red Flag Warning to
expire. Will keep small POPs in place through the evening hours
across the eastern CWA where some flurries or light snow showers
remain possible. No changes made to winds or temperatures at this
time.
&&
.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 153 PM CDT Sat Mar 16 2024
As of 1PM, skies were overall clear with fair weather cumulus clouds
pushing southeast with sustained winds of 20-30mph with some areas
gusting up to 40mph. As we head into this evening, winds will still
be on the gusty side, as a tighter pressure gradient continues from
the low positioned over Ontario, with forecasted gusts ranging from
30-35kts around 00Z. Once we lose daytime heating/mixing, winds will
diminish a bit overnight, however, CAA of -4 to -9C/12hr and 2 to
4mb/6hr pressure rises continues through the overnight and will help
maintain a "steeper" LLLR, mainly James River Valley and east
(closer to the low). Sustained winds of 10-15kts and gusts of 20-25
kts possible. Sunday afternoon with daytime mixing they do increase
a bit with gusts up to 30kts or so.
With north/northwest flow aloft over the area, a band of mid level
shortwave energy (wrapped around the low) sinks southward over the
central and eastern CWA tonight. This should be just enough lift for
possible light precip as GFS RH does show the air saturating from
850-925mb through Sunday morning with several Rap soundings across
the northeastern CWA showing this moistening of the column along
with omega from ~800mb-sfc. Several of the Cams back this up
indicating some vertical bands of light precip moving in from ND
here and there as this mid level energy continues over the area. So
with I blended in HRRR/RAP/ECAM along with NBM to show this. Any
precip that should fall will be minimal in the form of rain/snow or
snow. Prob of 0.01 per HREF runs between 10-40% with these bands.
Prob of over 0.05" is 20% or less.
This incoming high is bringing colder air with it as
850mb temps at 12Z Sunday are about 10 degrees cooler ranging from -
7 to -15C and 925mb temps -4 to -10C, coldest over northern and
northeastern SD/western MN. Even by Sunday afternoon, 925mb temps
still range in the single digits below zero east of the Mo river.
With this, overnight lows could be tricky for the James River Vally
and east as they should be lower than ensemble forecast, but we will
be dealing with some clouds from this low along with some wind, so
hesitant to go any lower than guidance. Similar to Sunday as temps
seem a little on the warm side so knocked them down a couple of
degrees. We do have a higher sun angle this time of year, so did not
want to drop them too much. Low confidence exists on temps tonight
and Sunday.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 153 PM CDT Sat Mar 16 2024
Still facing the gradual diminishment of western CONUS
ridging/eastern CONUS troffing during the front end of the out
periods. Beyond Wednesday, there remains too much dissonance in the
various (ensemble clusters) model camps regarding care of the upper
flow pattern`s evolution from Thursday onward. At some point between
Thursday and Saturday, models agree that there should be an upper
level trof working west to east across the central/northern plains
region. They just don`t agree on timing/track all that much right
now. Ensemble PoPs continue to paint a general 20 to 50% chance of
precipitation from Thursday through Saturday, with Thursday and
Saturday holding the higher end chances.
Not much has changed in 24 hours regarding temperatures. There is
still quite a bit of (box and whiskers) spread in potential
temperature outcomes next week from Wednesday onward. There is a
subtle cooling trend seen in the ensemble temperature data from
Thursday onward. Looking at 3-hrly probabilities of 2m temperature
being below 34 degrees during those periods containing PoPs, there
continues to be a note-worthy signal for conditions cold enough to
support snow for p-type.
While still under north-northwest flow aloft on Monday, the boundary
layer will take on a southwesterly wind configuration, with warm/dry
air advecting into the CWA. Grassland Fire Danger is already in the
High to Very High category, with a little bit of extreme category
showing up in western Corson County. Similar to what happened on
Friday, stronger mixing/gusting winds should start to materialize by
late Monday afternoon, and moreso across the northern half of the
CWA. Afternoon humidity is forecast to drop to 30 percent or less,
CWA-wide on Monday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 623 PM CDT Sat Mar 16 2024
Terminals KABR,KATY,KPIR,KMBG
VFR conditions will prevail across the area tonight and through
the day Sunday. Northwest winds in the 15 to 30 knot range may
lose their gustiness for a time overnight before increasing again
on Sunday.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Parkin
SHORT TERM...MMM
LONG TERM...Dorn
AVIATION...Parkin
Area Forecast Discussion
National Weather Service Bismarck ND
934 PM CDT Sat Mar 16 2024
.KEY MESSAGES...
- Breezy northwest winds, with a 20 percent chance of snow,
through tonight mainly central and eastern North Dakota.
- Cooler temperatures expected Sunday. Breezy northwest winds
lingering across portions of the south and the James River
Valley.
- Much warmer, dry, and breezy to windy conditions expected
Monday.
- Unsettled weather pattern middle through end of the upcoming
week bringing daily snow chances and cooler temperatures.
&&
.UPDATE...
Issued at 935 PM CDT Sat Mar 16 2024
Isolated to scattered snow showers continue across central North
Dakota this evening. Other than the brief quarter mile vsby at
Rolla this afternoon, most areas that received snow remained in
the 3-6SM range, but a few areas did drop down to 1-3SM
briefly. As of 9:30 PM, there were some scattered snow drifts
on the NDDOT website from the Turtle Mountains into the Devils
Lake Basin. Some of the areas far north that saw the snow
earlier, already looked to be at least partially dry. However,
any wet areas that do not dry off tonight will likely ice up so
there will probably be some patchy icy spots tonight over
eastern portions of central ND, mostly from the Turtle Mountains
south through the James River Valley.
Currently, RAP analysis shows the snow squall parameter
maximized over eastern Stutsman, Lamoure and Dickey counties and
dropping south. Although snow squall parameters lined up this
afternoon/evening overall they were pretty weak. Potential
instability and low level moisture were modest at best and there
wasn`t a strong low level focus for ascent. Lapse rates were
steep and winds were strong so there was a convective nature to
the precip and enough winds lower visibilities in the heavier
snow shower, but stronger more focused convective snow showers
didn`t really develop. There should be enough forcing though to
keep a mention of light snow through the evening hours, with
chances likely tapering overnight as high pressure builds from
the northwest.
Sky cover and PoPs were updated based on latest radar and
satellite imagery and a blend of short term guidance through the
early overnight hours.
.UPDATE...
Issued at 620 PM CDT Sat Mar 16 2024
Isolated to scattered snow showers continue from north central
ND into the James River Valley. Current obs and webcams show
minimal impacts so far. However, Rolla did drop down to a
quarter mile briefly as a heavier snow shower moved over.
Currently, the strongest reflectivities are over eastern Foster
and northeast Stutsman counties and moving south southeast.
Latest RAP analysis shows better parameters for snow squalls
moving into the far northeast CWA in the next 1-2 hours and then
sliding through the JRV around mid evening. Will continue to
monitor. Made some minor adjustments to sky cover based on
latest satellite imagery. Otherwise no significant changes to
the going forecast.
&&
.DISCUSSION...
Issued at 340 PM CDT Sat Mar 16 2024
Cyclonic unsettled flow aloft will allow snow showers to become
abundant through the evening, and possibly lingering into the
overnight hours. Still of note is an increased snow squall
parameter in some of the higher res guidance mainly in the
northeast and east of Highway 3. Looking closer into this, there
is increased 0-2 KM moisture in these areas through tonight.
Winds in the lower levels are increased as well with some weak
convergence at times, yet start to diminish tonight. Instability
is present, although on the to modest end. There is decent
lapse rates, with surface based CAPE generally less than 75
J/KG. Thus looking at individual components of the snow squall
parameter cannot rule out an isolated burst of heavy snow,
especially in the northeast and areas east of Highway 83 where
decreasing theta-e will be found through the night. Otherwise
look for some breezy west northwest winds to linger across the
east through tonight. Low temperatures will be in the teens with
some lower 20s. Perhaps some clouds and isolated snow showers
lingering through Sunday morning. Clouds then diminish in
coverage through the day, with cooler temperatures expected.
Some breezy northwest winds may also linger, mainly in the south
and east. These winds then diminish Sunday night and become
southerly. Lows Sunday night will once again be in the teens to
lower 20s.
With a passing surface low and building ridge aloft, Monday is
expected to overall be warm and dry. A light and variable wind
in the morning will become a breezy southwest wind, switching to
a breezy to windy west northwest wind later in the day. These
winds could perhaps approach advisory level, although a quick
glance at the ECMWF EFI shows low confidence in this. However, with
warming temperatures in the 50s to lower 60s, afternoon
humidity values could drop into the 20s. This could lead to
perhaps some near critical fire weather conditions, especially
south of Interstate 94, and even more specifically in
southwestern ND where afternoon high temperatures could be in
the 60s. Ridge starts to flatten on Tuesday perhaps allowing a
weak front to push across the area. This will cool down
temperatures, although they could remain above normal. Mainly
dry conditions are also expected through Tuesday.
This flattening of the ridge could open the door for more active
weather starting mid week. The chance for at least 1 inch of
snow in the NBM Wednesday through Thursday is in the range of 40
to 80%, with the chances for at least 6 inches less than 20%.
There remains uncertainty on timing and strength of the
disturbance that pushes through. This is also seen in the
temperature spreads in the NBM, although most still indicate
cooler than recent pattern. Late in the week into next weekend
could also remain cooler and potentially active. The spread in
ensembles provides the NBM to keep in chance pops for snow each
day, while temperature spreads remain somewhat wide yet still on
the cooler side. Of note is currently the NBM has higher chances
for at least 1 inch and 6 inches of snow in a 48 hour period
over the upcoming weekend compared to the mid week event. This
could be from some ensembles showing a deeper wave moving across
the US. This is currently about 50% of ensembles, so the finer
details will still need to be worked out and monitored.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 935 PM CDT Sat Mar 16 2024
Low VFR to MVFR ceilings are possible at KMOT, KBIS and
especially KJMS this evening through Sunday morning. Scattered
snow showers could produce short periods of MVFR to IFR
visibilities at these TAF sites this evening and possibly
lingering into the overnight hours. VFR ceilings are expected to
prevail across western ND including KXWA and KDIK through the
00Z TAF period.North to northwest winds sustained around 20-25
knots gusting to around 30-35 knots early this evening will
diminish but will remain breezy across the forecast area around
10 to 15 knots western ND and 15 to 20 knots central ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...TWH
DISCUSSION...TWH
AVIATION...TWH
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
645 PM CDT Sat Mar 16 2024
...New AVIATION...
.SHORT TERM...
(Tonight through Sunday night)
Issued at 255 PM CDT Sat Mar 16 2024
A cut-off low over the Desert Southwest will promote southwesterly
flow aloft over Deep South Texas through the short term period. A
shortwave moving moving overhead tonight will provide additional
forcing. At the surface, southeasterly flow has allowed warm and
humid air to return to the region this afternoon, this will support
CAPE values reaching >1500 J/kg this evening, as well as PW values
around 1.5”. The combination of the moisture, instability and
forcing look to provide an environment favorable for convection,
especially the western half of the CWA. Model soundings from the 18z
run of the RAP are showing shear and thermodynamic profiles that
could support the development of severe thunderstorms over the
western most counties. The Storm Prediction Center’s day one
convective outlook has a Slight risk over northwestern portions of
Zapata and Jim Hogg counties, and a Marginal Risk over the
remainder of of Zapata and Jim Hogg counties, as well as Starr,
Brooks, and northwestern portions of Hidalgo and Kenedy counties.
The primary threat is expected to be damaging hail and wind, however
a very limited tornado threat is also possible. Additionally, some
heavy rain is possible with these storms, and the Weather Prediction
Center has a marginal risk for excessive rainfall for parts of
Zapata, Jim Hogg, Brooks, Kenedy and Hidalgo counties.
A general thunderstorm threat continues further east, however
stronger CIN and lower CAPE values are forecast closer to the coast,
which will limit the severe potential. A cold front currently
situated over South/Central Texas is expected to move through Deep
South Texas Sunday. Additional isolated to scattered showers and
thunderstorms are possible through the day Sunday. Rain chances
decrease, behind the front Sunday night, however potential for some
light rain or an elevated thunderstorm looks to stick around as a
weak overrunning setup looks take hold.
Low temperatures tonight are expected to drop into the upper 60s to
low 70s. Temperatures are expected to climb back to the low 80s
Sunday, ahead of the front. Sunday night, temperatures are expected
to fall to the upper 50s to mid 60s behind the front.
&&
.LONG TERM...
(Monday through next Saturday)
Issued at 255 PM CDT Sat Mar 16 2024
The long term forecast pattern will start off with a Rex Block being
set up between a cut-off low over the Desert Southwest and a ridge
over the Pacific Northwest that will last through the mid-week. This
will allow for an active pattern to persist over Deep South Texas and
the Rio Grande Valley as a series of shortwaves will move through
the area due to the southwesterly flow aloft. However, with this
active pattern there is a great potential for much needed rainfall
to occur. PWAT values through the period remain high in the range of
1.6 to 1.8 through Thursday, before they drop off on Friday.
The downside to this active weather pattern is that there is the
potential for more severe weather to occur. Mid-week looks to be a
key time for the long term forecast period as storms coming off the
Mexican plateau move towards Zapata, Starr, and Hidalgo counties.
The primary threat with these kind of storms are the large hail.
Overrunning showers or isolated thunderstorms are possible for Monday
and Tuesday. With the onshore flow, there will be plenty of moisture
to help fuel these developing storms.
&&
.AVIATION...
(00Z TAFS)
Issued at 637 PM CDT Sat Mar 16 2024
Low probability of convection at the regional airports overnight
but if convection does develop expect strong to severe
thunderstorms with towers over 40K feet. Otherwise, ceilings to
develop and lower overnight with MVFR to IFR conditions. IFR
expected around sunrise and gradually lift through the morning in
advance of a slow moving cold front. Ceilings may remain in MVFR
category or briefly lift to VFR before lowering back down as the
weak front moves south of the region. Convection is expected to
become scattered Sunday as the front moves into the region. Light
southeast to east winds tonight and Sunday in advance of the
front. A northwest to northeast breeze gusting 15-20 knots is
possible late Sunday.
&&
.MARINE...
Issued at 255 PM CDT Sat Mar 16 2024
Tonight through Sunday Night...Showers and thunderstorms are
possible over the Gulf waters and Laguna Madre tonight through
tomorrow night. The best rain chances are tonight, with
probabilities decrease through the day Sunday, and only limited rain
Chances by Sunday night. Otherwise, generally favorable conditions
are expected to continue through the short term. Light to moderate
southeasterly flow will continue tonight and into the day Sunday,
however a cold front late Sunday morning into Sunday afternoon will
slowly shift wind more northeasterly. Winds look to begin increasing
late Sunday night into early Monday morning, and adverse conditions
requiring a Small Craft Advisory or Small Craft Should Exercise
Caution headline are possible near the end of the period.
Monday through Next Saturday...A hazardous start on Monday with
elevated winds and seas that will require a Small Craft Advisory
with 30 knot winds possible for the nearshore Gulf waters and Laguna
Madre. However conditions will start to improve moving into Tuesday.
Winds turn towards the east then southeast during the week leaving a
favorable pattern through next Saturday. Showers and thunderstorms
are possible through Thursday, with gusty winds and hail possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 71 83 67 73 / 20 30 20 30
HARLINGEN 69 85 64 72 / 30 30 20 20
MCALLEN 71 86 66 72 / 40 30 30 30
RIO GRANDE CITY 68 82 63 71 / 50 20 30 50
SOUTH PADRE ISLAND 69 74 67 70 / 20 30 10 20
BAYVIEW/PORT ISABEL 69 79 65 72 / 20 30 10 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...60-BE
LONG TERM....64-Katz
AVIATION...59-GB
Area Forecast Discussion
National Weather Service Indianapolis IN
1203 AM EDT Sun Mar 17 2024
.KEY MESSAGES...
- Becoming Partly Cloudy Tonight
- Colder Tonight and Sunday
- Hard freeze likely Sunday Night and Monday night
- Isolated rain/snow showers possible Monday, mainly in the
afternoon
&&
.SHORT TERM (This evening through Sunday)...
Issued at 259 PM EDT Sat Mar 16 2024
Synopsis:
Surface analysis early this afternoon shows high pressure centered
over KS/OK/AR with a ridge axis stretching east to KY. Low pressure
was found north of the Great Lakes with a moderate pressure gradient
in place across WI and MI. These two systems were resulting in
southwest flow across Central Indiana. A cold front was found across
Lake Michigan, southern WI and west into IA. GOES16 showed mostly
clear skies across Indiana, however an area of clouds was found in
the wake of the front over WI, IA and MI within the cyclonic flow
and an associated upper level disturbance. Radar mosaics show only
some some very light rain fall with this front over SW MI. Aloft,
water vapor showed a deep low over Ontario, with northwest flow
spilling south across the northern plains to Indiana and the Ohio
Valley.
Tonight...
Overall expect increasing clouds this evening and cooler
temperatures associated with passage of the cold front.
Models suggest the cold front to the north will push southeast
across Central Indiana this evening. An upper level disturbance
embedded within the cyclonic flow aloft will also accompany the cold
front. This will provide enough lift along with cold air advection
in the wake of the front to result in some mid level saturation
passing in the wake of the front. This effect can already be seen on
GOES16 as previously discussed. Time heights and forecast soundings
both depict mid level saturation as these features pass. Best
saturation will be found across the northeast parts of the forecast
area, closest to the cyclonic flow, with lesser moisture and fewer
clouds to the southwest. Thus overall, increasing clouds late this
evening, and then clearing late overnight as the clouds are expected
to depart.
Strong cold air advection will remain in play in the wake of the
front. 850MB temps are suggested to fall toward -6C by 12Z, and
this cold air advection pattern will persist into Sunday. Thus lows
in the middle 30s will be expected.
Sunday...
Dry but colder weather is expected on Sunday. The deep low
pressure system over Ontario is expected to move to Quebec, while a
strong area of Canadian high pressure sets up over Saskatchewan.
This strong high will extend its influence south along the high
plains and east through the Mississippi valley. This will set up a
classic northerly transport of cold Canadian air across the upper
midwest to the Ohio Valley for Sunday. Forecast soundings suggest a
dry column through day, however some afternoon CU will be possible
as convective temperatures in the 40s are reached. This should be
rather minimal during the late afternoon hours. Thus Partly Cloudy
should work for the day. The moderate pressure gradient will remain
in place across Central Indiana also. This will result in gusty
northwest winds up to 25 mph through the daytime heating hours.
As cold air advection continues through the afternoon, 850mb temps
are suggested to fall toward -8C to -9C. Thus highs only in the
middle to upper 40s will be expected.
&&
.LONG TERM (Sunday night through Saturday)...
Issued at 259 PM EDT Sat Mar 16 2024
Sunday night through Monday night...
The long term period begins with a deep upper trough moving into the
region from the northwest bringing much colder air. Cold air
advection will lead to below normal temperatures through Monday
night. Early onset to greenup will likely be impacted by sub-
freezing temperatures and probable hard freeze Sunday night/Monday
morning and again Monday night/Tuesday morning. Widespread mid-upper
20s are expected for minimums across central Indiana both nights.
Breezy conditions are likely going to make it feel even colder. Wind
chills could fall into the teens both nights. Forecast confidence in
temperatures is high since guidance is in great agreement showing
little variability.
Dry conditions are likely Sunday night as surface ridging is in
place. By Monday morning, it appears there is at least a low chance
for an isolated snow shower or flurries. Low-level dry air and lack
of forcing limit confidence in precipitation chances during the
morning, but steepening low-level lapse rates within the cold air
advection regime should promote isolated light rain/snow showers
during the afternoon. RAP soundings show impressive 0-3km lapse
rates near 9 c/km and sufficient low-level instability for at least
isolated coverage. Only slight POPs were added at this time, mainly
across N/NE counties, due to some uncertainty with low-level dry
air/limited moisture over the area. Snowfall accumulations or
impacts are unlikely due to warm ground temperatures.
Tuesday onward...
As western high-latitude ridging and blocking pattern break down mid-
week, a quasi-zonal split flow regime will develop. The most
uncertain part of the forecast in the long term period is onset of
warming, which in some ensemble clusters is more rapid than others
(i.e., non-EPS weighted clusters). Regardless of specific
temperatures in the Tuesday-Wednesday time period, a warming trend
will be ongoing by then.
These split flow patterns are notorious for confining the deepest
moisture to low latitudes and it appears only modest moisture will
return with warm advection late week. Ensemble clusters are split
into the EPS-weighted drier pattern with dominate southern stream
wave, and GEFS-weighted wetter more amplified northern stream wave.
Thus, mid-range/chance probabilities are assigned for late Thursday
into Friday. Regardless, this will be a light precipitation event
per even the wettest outlier ensemble members.
&&
.AVIATION (06Z TAF Issuance)...
Issued at 1203 AM EDT Sun Mar 17 2024
Impacts:
- Gusty winds again Sunday
Discussion:
Post-frontal winds will gradually subside through early morning
before becoming gusty again with the diurnal mixing cycle tomorrow.
VFR conditions will prevail. Forecast confidence is high.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Puma
LONG TERM...Melo
AVIATION...BRB
Area Forecast Discussion
National Weather Service North Platte NE
626 PM CDT Sat Mar 16 2024
.KEY MESSAGES...
- Cooler and breezy conditions on Sunday with highs falling
slightly below normal into the 40s.
- Elevated to near critical fire weather conditions through
Tuesday due to dry conditions with breezy winds at times.
- Temperatures rebound back into the above-normal range generally
in the 50s and 60s Monday through the end of the week.
- A weather pattern shift is expected heading into the weekend
which may bring an increased threat for precipitation across
the area, though specific details remain uncertain at this
time.
&&
.SYNOPSIS...
Issued at 230 PM CDT Sat Mar 16 2024
Recent GOES-16 WV and RAP 500-mb analysis showed a meandering closed
low pressure system spinning over the Desert Southwest. Further
northwest of this feature, upper-level high pressure was pushing
onshore over the Pacific Northwest with troughing over the Gulf of
Alaska into the north Pacific. A closed off upper-level low pressure
system was centered over central Ontario with a trough extending
south into the Ohio River Valley. This system is vertically stacked
with surface low pressure noted and an attendant cold front
extending west-southwest, advancing southward across central Nebraska.
High pressure was dipping southward out of central Canada into
Montana and North Dakota. Efficient mixing and pressure rises
behind the front with the surface pressure gradient (SPG)
tightening between the two surface features has led to gusty
north- northwest winds today. Outside of some mid to high clouds
passing by, mostly sunny skies prevail across western and north
central Nebraska this afternoon. As of 2 PM CT, temperatures
ranged from 46 degrees at Gordon to 54 degrees at North Platte
with recent peak wind gust observations of 30 to 40 miles per
hour.
&&
.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 230 PM CDT Sat Mar 16 2024
Sunday and Sunday Night... Colder air will begin to work into
the area as dry and breezy northwest flow continues Sunday into
Sunday night. High temperatures on Sunday will struggle to climb
out of the 40s with the exception being far southwest Nebraska
where low to mid 50s will be felt. The dry airmass behind the
front will lead to lowest humidity falling to 20 to 25 percent
combining with north to northwest wind gusts of 25 to 35 mph
will result in elevated to near- critical fire weather
conditions. Despite the cooler temperatures and minimum RH not
reaching critical values of 15 to 20 percent precluding any
headlines, any fire starts Sunday afternoon could spread quickly
given the gusty winds. The previously mentioned surface high
pressure will continue to push southward through the day on
Sunday, centering over central Nebraska overnight. Much colder
low temperatures in the teens settle in as a result under clear
skies.
Monday and Monday Night...As we head into Monday, the upper-level
ridge will build further into the western CONUS with surface high
pressure continuing southward into the southern Plains. High
temperatures rebound back into the 50s to low 60s with clear skies
prevailing across western and north central Nebraska. With such warm
and dry air in place, afternoon humidities will bottom out into the
18 to 25 percent range, especially for areas along and east of
Highway 83. However, being in close proximity to the surface high
pressure will result in lighter winds with gusts of 25 miles per
hour or less expected. Given this, fire concerns will be
marginal with elevated conditions anticipated during the day.
Surface low pressure will drop southward out of Manitoba into
the Great Lakes region with an attendant cool front forecast to
sweep through the area overnight. While the temperature
advection will be weak, a combination of a tightening SPG and
strong mechanical mixing behind the front will result in winds
strengthening out of the northwest overnight Monday into early
Tuesday morning with widespread gusts of 20 to 30 miles per hour
are expected.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 230 PM CDT Sat Mar 16 2024
The upper-level pattern for the start of the long term will be
defined by an Omega Block, not too much different than today.
The stubborn closed low will continue across the Desert
Southwest with high pressure centering over the Pacific
Northwest and the Great Basin. On either side of these features,
troughing will be evident across the Gulf of Alaska into the
north Pacific and over the eastern third of the CONUS. As the
upper-level ridge continues to build across the western CONUS,
dry conditions with unseasonably warm temperatures in the 50s
and 60s will continue through mid-week. However, confidence
wanes some in regards to temperatures given the spread amongst
model solutions increasing on Wednesday and Thursday due to
colder air intruding from the north. This is highlighted by
large standard deviation values, specifically for next Thursday.
Given this is around the 5 to 6 day mark in the forecast, do
expect the spread to narrow some with subsequent forecasts, thus
will stick to the NBM solution with this forecast issuance.
Elevated fire weather conditions will be possible through mid-
week with breezy winds at times, though subtle increase in low-
level moisture will lessen overall concerns.
On Thursday, quasi-zonal flow aloft will set up with the upper-
level low currently across the Desert Southwest finally makes
way across the southern Plains. Beyond this, considerable
differences amongst model solutions exists on the overall
synoptic flow heading into the weekend which is apparent when
looking at upper-level spaghetti charts. Most guidance does
hint at the potential for a threat of precipitation returning
across the region, however, specific details regarding
precipitation type, amounts, and locations remains unresolved given
being nearly 7 days out. Given such low confidence on this
weekend`s precipitation chances, cannot argue with the NBM`s
forecast of slight chance/chance (20 to 35%) PoPs. Will need to
continue to monitor trends in the coming days with this system.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 626 PM CDT Sat Mar 16 2024
Expect mostly clear skies over the next 24 hours with a few high
clouds possible around 25000 FT AGL. Winds will be from the
north at around 10 KTS tonight. By mid morning, wind speeds will
increase with gusts to around 25 KTS in the afternoon on Sunday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Viken
SHORT TERM...Viken
LONG TERM...Viken
AVIATION...Buttler
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
715 PM CDT Sat Mar 16 2024
.KEY MESSAGES...
- West to northwest winds with strong gusts of 30 to 40 mph are
expected to continue through the early evening, diminishing
overnight.
- Relatively cooler temperatures are expected Sunday and Monday
with periods of wind chills in the teens to twenties and
flurries.
- Temperatures warm back into upper 40s to lower 50s Tuesday
onward with the next chance for region-wide precipitation
toward the end of next week.
&&
.DISCUSSION...
Issued at 256 PM CDT Sat Mar 16 2024
Through Sunday Night:
The winds that are currently out of southwest will continue to
rotate to the west and eventually northwest this evening. Winds
are gusting between 35 to 40 mph. Strongest gusts are expected
to slowly diminish through the evening, but there is lower
confidence on the exact timing for when they taper off. With the
surface front entering northern Illinois at the time this
discussion was published, cold air advection behind the front
will keep the stronger gusts around through at least sunset.
Relative humidities are hovering in the 40 percent range, though
it would not be surprising if there are some localized spots
that may drop into the upper 30s this afternoon. The enhanced
risk for brush fires remains through at least sunset, but
humidity should recover overnight.
The cold air moving down behind the front will drop temperatures
on Sunday morning below freezing, with only the city remaining
with a chance to stay above freezing. Though winds will
diminish, they will still be enough to create wind chills in the
teens and twenties into Sunday morning. The next upper level
wave will move southward from Canada later on Sunday morning
with a strengthening upper level jet helping to provide an area
of enhanced lift. Steepening low-level lapse rates within the
cold air advection regime would provide the potential for snow
showers Sunday afternoon and early evening. However, the main
issue that models have struggled with this wave over several
runs is the low level moisture field. The HRRR and the RAP have
been noticeably colder and more moist, while most other models
have struggled to find enough moisture to suggest any precip at
all. The forecast was updated to keep the slight chance for a
snow shower (maybe more graupel then snow), but it would like be
for a short duration, with light flurries perhaps being the
more dominant precip type. Additionally, if it does snow,
pavement temperatures will likely remain above freezing limiting
the threat for any accumulation. As Sunday night approaches and
the main front moves south and east of the area, persistent
northwest winds with lake induced instability and equilibrium
levels to 8000 ft offer the potential for lake effect snow over
Northern Indiana. While the best chances remain to the east,
Porter County has the best chance (15 to 25 percent) for light
lake effect snow accumulations into Monday morning.
Monday through Saturday:
As the upper level trough finally moves to the east, high
pressure will start to grow over the Southern Plains. Northerly
flow will help keep temperatures cool through Monday with
another chilly night where wind chills could once again drop
down to the high teens and low 20s. Models are still suggesting
a weak short wave trough moves over on Tuesday, but moisture
profiles look far too dry to result in any precipitation. Low
level winds will switch around to the southeast midweek
allowing a bit more warm air advection and help bring
temperatures back up into the seasonal norm, if not slightly
above.
Ensemble models are suggesting the an upper level low that is
currently over desert southwest will slowly eject eastward by
the middle of the week. Most models show this wave weakening as
it moves east, but are disagreeing with its track. Euro
favoring a southern movement has a drier forecast, whereas the
GFS has it moving just north enough with modest moisture
advection to provide another chance for rain late Thursday into
Friday with even a chance of snow mixed in Thursday night.
DK
&&
.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 715 PM CDT Sat Mar 16 2024
Gusty west to northwest winds are expected through the TAF
cycle. Occasional gusts to around 30kt are possible at times.
SCT to BKN VFR deck this evening should trend more toward
FEW/SKC overnight, before another BKN VFR deck bubbles up
Sunday. WDLY SCT -SHSN or possibly some -GS (graupel) are
possible during the afternoon. Dry air near the surface may
result in mostly virga, and it is this uncertainty that has led
to only running with PROB30. Otherwise, no big weather impacts
expected at the terminals.
- Izzi
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Gale Warning until 7 PM CDT this evening for Winthrop Harbor
IL to Gary IN.
Small Craft Advisory until 10 PM CDT Sunday for Winthrop
Harbor IL to Gary IN.
Small Craft Advisory until 1 PM CDT Monday for Gary to Burns
Harbor IN-Burns Harbor to Michigan City IN.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
907 PM CDT Sat Mar 16 2024
.KEY MESSAGES...
- Elevated fire weather conditions through early next week.
- Winds diminish slightly tonight and Sunday, however gusts
upwards of 35 mph will remain possible at times.
- Light precipitation chances return for the end of the work
week.
&&
.DISCUSSION...
Issued at 257 PM CDT Sat Mar 16 2024
It`s been an interesting day of weather following the passage of a
cold front early this morning. Early morning temperatures in the low
50s cooled quickly to the upper 30s and low 40s after daybreak
following the frontal passage, but have warmed back into the mid 40s
early this afternoon. Northwesterly winds have taken center stage
today, with the highest gusts in the 35-40 mph range. Despite
minimum RH values between 30-40 percent, fire weather concerns
remain at critical levels this afternoon due to very dry fuels and
continued strong northwesterly winds. A Red Flag Warning continues
through 8 PM this evening. Additional fire weather headlines are
possible Sunday, though winds are expected to be slightly less
intense (sustained winds 15-20 mph & gusts up to 35 mph). Of course,
it`s also forecast to be much colder.
Winds have strengthened in response to a tight pressure gradient
associated with a potent ~990s mb surface low moving southeast out
of Ontario into the eastern Great Lakes. A reinforcing shot of cold
air will advect southward into the Upper Midwest tonight. Lows will
dip into the upper teens/low 20s overnight, which will combine with
breezy winds to produce wind chills in the single digits around
daybreak. There is a low chance that a few flurries fly from Sunday
afternoon through midday Monday, though any occurrence would be
rather inconsequential. RAP forecast soundings depict marginal
saturation in the DGZ around 5kft, in tandem with some low-level
forcing. For now, we`ve opted to keep any appreciable PoPS out of
the grids, but will leave the door open for introducing flurries
should forthcoming CAMs illustrate this trend further. Colder, below
normal air sticks with us through the early part of the week, as
highs are forecast to top out in the 30s Sunday and Monday.
Hopefully the record warmth as of late did not fool anybody into
putting the cold weather gear away just yet!
A fast moving clipper will slide into the Great Lakes Tuesday, with
the best chance for precipitation to the east of Minnesota and
western Wisconsin. While the forecast is expected to remain dry, we
are forecasting a notable one-day warm up, as a wing of warm
advection on the southwest flank of the clipper moves overhead.
Latest NBM guidance seems to have good handle on this warm up, with
highs in the mid to upper 40s possible over much of the area. We`ll
need to keep an eye on the wind projections for Tuesday, as the
close proximity to the progged surface low may yield advisory level
winds (and potential fire weather concerns) through the afternoon.
The brief warm up will give way to cooler temperatures back in the
upper 30s/low 40s by Wednesday and Thursday.
We can use one word to describe the end of the work week into next
weekend: active. While there remains a significant amount of
uncertainty in the evolution of several upper-level features
across the global guidance, the combined suite of solutions
brings higher probabilities for measurable precipitation than
we`ve seen in some time. Beginning Thursday, a shortwave is
forecast to move into the Northern Plains amid large scale zonal
flow aloft. Forecast thermal profiles tend to support snow as
the dominant p-type across the region. NBM PoPs in the 30-50%
range seem fair at this distance, for what appears to be
scattered snow showers. Following this wave, ensembles
advertise a relatively deep trough digging over the western
CONUS next weekend, with the potential for a more significant
storm system to develop in response. Again, a large amount of
variability exists among the guidance this afternoon, but the
active pattern with potential precipitation chances bears
watching.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 650 PM CDT Sat Mar 16 2024
VFR conditions throughout with stratus. Overall expect cloud
bases above 3000 ft, but could have it drop down to MVFR levels
at times Sunday morning at KAXN, KSTC, and KRNH.
KMSP...VFR conditions throughout with steady northwest winds at
15G25kts overnight and through Sunday. Winds will start to
decrease around Sunday evening. Expect a broken stratus deck but
bases should be above 3000 ft.
/OUTLOOK FOR KMSP/
MON...VFR. Wind NW 5-15 kts.
TUE...VFR. Wind NW 10-15G25-30kts.
WED...VFR. Winds NW 10-15kts.
&&
.FIRE WEATHER...
Issued at 904 PM CDT Sat Mar 16 2024
The fire weather threat for Sunday will be less than it was on
Saturday.
Saturday was a windy and dry day, with most locations
having RH values bottom out near 30 percent, and wind gusts
near 35 to 45 mph. On Sunday, winds will be a bit less, with
gusts of 25 to 35 mph, and humidity will be a bit higher, with
values of 30 to 40 percent.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Strus
AVIATION...JRB
FIRE WEATHER...JRB
Area Forecast Discussion
National Weather Service Marquette MI
1055 PM EDT Sat Mar 16 2024
.KEY MESSAGES...
- Lake effect snow tonight into Monday, especially over the
western U.P. near Lake Superior. Highest snow amounts of 5-9
inches possible across mainly the western counties. Elsewhere
in the northwest wind snow belts, 2-5 inches is possible.
- A prolonged gale event on Lake Superior continues into Sunday
night.
- Blustery northwest to north winds continue through Sunday.
- The snow, combined with blustery winds, will result in some
hazardous driving conditions.
&&
.UPDATE...
Issued at 1054 PM EDT Sat Mar 16 2024
Water vapor imagery and RAP analysis show a mid-level low centered
btwn Lake Superior and James Bay. Upper MI is firmly under the
influence of this feature with deep cyclonic flow across the area.
Deep moisture is also present across the area, including upstream
per 00z CWPL sounding. With 850mb temps continuing to fall, lake
enhanced snowfall has been increasing into Upper MI, especially in
the area btwn Painesdale and Rockland e into Baraga County and
western Marquette County. This is an area where low-level
convergence is more focused attm.
With abundant deep moisture/deep cyclonic flow and 850mb temps
continuing to fall, bottoming out at -14 to -17C on Sun, it`s a good
setup for lake enhanced snowfall thru Sun. Fairly sharp inversion
setting up at 4-5kft on Sun as seen on 00z CWPL sounding will be a
limiter with time, keeping snow accumulations from being much
higher. Given trends this evening, opted to expand advy into
southern Houghton/Baraga counties where mdt to locally hvy snow is
currently falling. Slight veering of winds should gradually shift
best convergence/heaviest snowfall to the sw during the night. To
the e, included northern Schoolcraft into the advy and bumped up
starting time of advy for Alger/northern Schoolcraft given radar
trends.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 221 PM EDT Sat Mar 16 2024
With the initial cold front now having passed most of the U.P.,
blustery northwesterly winds are being seen across the area,
particularly over the Keweenaw where Houghton has already gusted up
to 43 mph as of 1 PM EDT. Meanwhile, the radar has shown scattered
snow showers developing in the western U.P., with a quick burst of
heavy snow having already occurred at the office in Negaunee
Township. As more organized precip (rain/snow) activity leaves the
far eastern U.P. this afternoon, isolated to scattered snow showers
look to take its place late this afternoon. As cold air advection
continues to cycle over us into the overnight hours, lake-effect
snowfall begins to pick up across the northwest snow belts as the
DGZ finally gets to around 13C, especially over the west. The
snowfall eventually becomes lake-enhanced late tonight as a
secondary cold front drops down from northern Ontario. With
temperatures continuing to fall the rest of today through tonight,
forcing gradually moving into the DGZ, and the moisture profile
slowly moistening with time due to the incoming secondary cold front
late tonight, I`m thinking we could see fluffy snowfall
accumulations of 3 to 5 inches across the western U.P. near Lake
Superior tonight, with some isolated spots possibly getting up to 6
or 7 inches. Meanwhile, over the rest of the northwest snow belts
tonight, it`s very likely (80 to 90% chance) that snowfall
accumulations will be around 2 inches or less, although a spot or
two could reach up to 3 inches. With the blustery conditions
continuing tonight, some patches of blowing snow will likely (70%
chance) be seen near the Lake Superior shoreline. Therefore, the
main hazards tonight will be slick road conditions, reduced
visibilities, and quickly accumulating snowfall at times. This could
increase accidents across the area if people don`t drive carefully.
Therefore, be sure to drive slower, use your low-beam headlights,
and give some extra space between the car in front of you and
yourself.
&&
.LONG TERM /SUNDAY THROUGH SATURDAY/...
Issued at 332 PM EDT Sat Mar 16 2024
The extended forecast period is largely dominated by a broad ridge
extending up the west coast and downstream troughing extending down
the east coast. Both the ridge and trough will ebb and flow as
shortwaves ride down into the trough through the first half of the
week, but will help support cooler air over the region. We finally
see an evolution in the pattern late in the week as zonal flow sets
up over the region. In terms of sensible weather, expecting this
pattern to promote gusty winds and snow chances for much of the
coming week.
Sunday, the surface low currently analyzed just south of James Bay
will be drifting over the Ontario/Quebec border. Another shortwave
rotating around this feature will drop through the Great Lakes
during the day, with another surge of synoptic forcing and CAA.
Blustery and chilly NW flow, with 850mb temperatures falling to
around -12 to -15C, will keep lake effect snow going Sunday and at
least through Sunday night in the NW wind snow belts. Model
soundings show inversion heights around 5k feet, some lift within
the DGZ, and, depending on the model, prolonged access to the DGZ.
Thus, we could be looking at fairly decent snowfall rates at times,
with the HREF generally point to snowfall rates up to a 0.25-
0.5in/hr Sunday and through the first half of Sunday night. There
are some hints at higher embedded snowfall rates up to an inch
(around a 20% chance). Ensembles continue to favor several more
inches of snow in the NW wind belts during this time, with a 50-90%
chance of exceeding another 3 inches and ensemble means showing a
widespread 3-6 inches along the wind belts of the western UP, across
the highlands of Marquette and Baraga counties, and across Alger
county. There is a small chance (20%) that some isolated areas in
the western UP, where terrain enhancement can occur, to pick up
totals in excess of 6 inches.
Blustery winds will accompany the snow. Within the boundary layer,
model soundings suggest winds upwards of 35 mph will be possible.
These stronger winds will be most probable near Lake Superior, but
the deeper mixing from daytime heating could support winds of 25 mph
region-wide before waning Sunday night. Given a dry, fluffy snow
character with SLRs closer to 20:1 looking reasonable, blowing and
drifting snow will be possible. Outside of the northwest lake effect
snow belts, some flurries will be possible, but Sunday should mostly
be dry and with blustery winds. Daytime highs Sunday and Monday
appear mostly to be in the upper 20s to low 30s. Overnight lows
Sunday night will be in the teens and low 20s.
The heaviest of the LES tapers off through the second half of Sunday
night as soundings begin to dry out and inversion heights lower.
Weak surface ridging into Monday will see winds backing more W/SW,
and with drier air working in, LES should wrap up entirely over most
of the area. However, through the first half of the week, Upper
Michigan remains within northwest flow aloft and at the whim of any
shortwave/clipper system pressing southeast out of Canada. The first
such system will dive into the region Monday night and Tuesday.
There`s some uncertainty in where the surface feature will track and
Upper Michigan`s relative position to it. But this would be the next
shot for snow. Inverted surface trough may linger overhead into
Wednesday thanks to another punch of cold air aloft. This would
extend the post system lake enhanced/effect snow potential. Beyond
this, a surface high will track into the region, creating a mostly
dry period on Thursday apart from lingering LES potential across the
eastern UP. Friday into the weekend, we will generally be under
zonal flow aloft with a closed upper low centered over northern
Ontario. This will continue to leave us sensitive to hit and miss
snow chances as poorly-timed shortwaves rotate around this.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 752 PM EDT Sat Mar 16 2024
An increasingly favorable lake enhanced snow regime will be setting
up off of Lake Superior during this fcst period under nw to nnw low-
level winds. At IWD, expect initial VFR to fall to MVFR by late
evening and then to IFR overnight thru Sun aftn. Some brief periods
of LIFR will be possible late tonight thru at least Sun morning. At
CMX, initial MVFR will fall also fall to IFR overnight thru Sun
aftn. Some periods of LIFR will likely occur at times overnight thru
Sun. At SAW, nw wind direction initially won`t be favorable for much
in the way of -shsn. Expect VFR this evening to become MVFR
overnight. Slight veering of winds more to the NNW Sun morning will
support an increase in -shsn at SAW, leading to vis also falling to
MVFR. Some periods of IFR will be possible on Sun at SAW. Expect
gusty winds to 20-35kt at all terminals throughout this fcst period
with the stronger gusts at CMX.
&&
.MARINE...
Issued at 332 PM EDT Sat Mar 16 2024
Colder air moving into the region is leading to blustery WNW winds
this afternoon, with gales to 35 knots mainly across the central and
eastern portions of the lake so far. Tonight, expecting winds to
further increase to near 40 kts across the east half of the lake
while turning more to the NW. The strongest gusts will be along and
east of a line from Passage Island, to Copper Harbor, to Marquette.
Internal probabilistic tools suggest near 100% chance of gales north
and east of the Keweenaw tonight and into Sunday evening. The same
guidance suggests 25-50% chance of high end gales north of the
Keweenaw.
Pressure gradient relaxes beginning Sunday afternoon, allowing for
the slow lightening of winds with gales falling off Sunday night. By
Monday morning, winds are mostly expected to be less then 30 kts,
with further weakening through the day. Expecting these light winds
to persist through Tuesday morning. Another system moving through
the region then will leave behind another punch of colder air and
tighter pressure gradient. Winds at the moment appear close to 30kts
with the strongest over the east half through Wednesday evening. A
few gale force gusts are not out of the question. Winds decrease
Wednesday night, coming in at or below 20 knots the rest of the
week.
With the higher winds and colder temperatures expected over the next
several days, we could see some moderate freezing spray late
tonight through Monday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory until 2 AM EDT /1 AM CDT/ Monday for
MIZ002>004-009-084.
Winter Weather Advisory until 2 AM EDT Monday for MIZ006-085.
Lake Superior...
Gale Warning until 2 PM EDT /1 PM CDT/ Sunday for LSZ240>242-
263.
Small Craft Advisory from 2 PM EDT /1 PM CDT/ Sunday to 11 AM
EDT /10 AM CDT/ Monday for LSZ240>242.
Gale Warning until 2 AM EDT Monday for LSZ243>251-264>267.
Lake Michigan...
Small Craft Advisory until 8 AM EDT Monday for LMZ221-248-250.
&&
$$
UPDATE...Rolfson
SHORT TERM...TAP
LONG TERM...LC
AVIATION...Rolfson
MARINE...LC
Area Forecast Discussion
National Weather Service Reno NV
1242 PM PDT Sat Mar 16 2024
.SYNOPSIS...
Mostly dry conditions and warmer temperatures are in the forecast
for the region through the middle of week with the exception of
southern Mono County seeing a low potential for light snow showers
this evening. Better precipitation chances and cooler temperatures
look to return to the area later in the week and going into the
weekend.
&&
.DISCUSSION...
The Rex Block upper air pattern continues today with an upper air
high over southern BC and an upper air low over northwestern AZ as
seen in the latest RAP analysis. Forecast models pretty much keep
the CWA between the two upper air features going through the rest of
today, Sunday, and into Monday with the high projected to slowly
make its way south towards the CWA while the low stays mostly over
AZ. By Tuesday, model guidance has the aforementioned high crossing
into northern Washoe county during the morning hours then moving
through the CWA into CA which will start pushing the upper air low
east out of AZ. The ECMWF shows a slightly quicker eastward
progression with the upper air low than the GFS at this time. On
Wednesday, forecast guidance shows the CWA underneath an upper air
ridge axis in the morning before the ridge moves eastward through
the day. On Thursday, an upper air trough looks to move towards the
Pacific Coast with the ECMWF continuing to be a bit quicker than the
GFS in the pattern progression allowing a southwesterly flow over
the CWA by the evening hours. The GFS starts to show the
southwesterly flow over the CWA beginning on Friday as its trough
moves close to the CWA while the ECMWF predicts its trough axis
reaching over the CWA late Friday. While long term models show some
disagreement in the upper air trough placement in the western CONUS
on Saturday, they do appear to agree with some shortwave
disturbances within the general flow over the CWA. Will continue to
monitor for better agreement going forward, but an early look at
next weekend`s upper air pattern appears to signal for some
precipitation chances for the CWA.
At the surface, the region looks stay mostly dry through the weekend
with relatively lighter winds with the exceptions of breezy
conditions in the higher elevations. An exception to the
precipitation potential is seen this evening though as there is a
slight chance of light snow showers (10-20%) in southern Mono County
due to a low in southern CA allowing for some wraparound
precipitation in its outer bands. Minimal new snowfall accumulation
is expected should the area see these showers. Going into next week,
dry conditions look to mostly persist on Monday through Wednesday.
However, the NAM shows some CAPE values around 500 J/kg in the
Sierra crest on Monday afternoon which may allow for a rumble of
thunder should precipitation occur in western portions of the CWA,
but precipitation chances at this time look to be on the low side.
Temperatures across the region look to be on a gradual warming trend
through the weekend and into the middle of next week with portions
of northwestern NV reaching the middle to upper 60s during the day
on Monday and then possibly even the lower 70s on Tuesday and
Wednesday.
For Thursday and going into the weekend, the region expects to see
daytime high temperatures cool down a few degrees on Thursday and
Friday due to cloud cover increasing with precipitation chances
rising which will hinder diurnal heating potential. Better
precipitation chances (between 15-40%) are seen on Friday for areas
along and west of the CA-NV border with some portions of the Sierra
Mountains seeing around a 30-50% probability of an inch or greater
of new snowfall. Northwestern NV sees some slight chances for
precipitation (around 15%) during the afternoon hours though a good
portion of Churchill and Mineral Counties look to stay on the dry
side. Slightly better precipitation chances (around 10-50%) are seen
currently on next Saturday with western portions of the region
seeing the higher probability and the eastern portions seeing the
lower portion of the probability range. The latest NBM shows the
Sierra Mountains with a 40-50% probability of measurable snow next
Saturday with portions to the east seeing very low chances as the P-
type could be light rain or a light rain/snow mix. Breezy to gusty
west-southwesterly winds are also seen to return to the region going
into the weekend with next Saturday seeing the potentially coolest
daytime high temperatures in the next seven days.
-078
&&
.AVIATION...
* A 15-25% chance of isolated light snow showers late this afternoon
near KBAN/KMMH, with VIS/CIGs briefly lowering to MVFR near any
showers. The eastern Sierra and the White Mountains will see
terrain obscurations with CIGs BKN030-050 this afternoon. Snowfall
amounts will be light between a trace and 1 inch in heavier cells.
* A ridge building over the West Coast will gradually warm
temperatures area-wide and bring mainly dry conditions this
afternoon through Wednesday. The only exception will be slight
chances for showers/thunder in Mono Co. and mainly west of the
crest Monday and Tuesday. Light winds, VFR conditions (except near
showers), and good flying weather will be the norm through the
first half of next week.
-Johnston
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
Area Forecast Discussion
National Weather Service San Angelo TX
640 PM CDT Sat Mar 16 2024
...New AVIATION...
.SHORT TERM...
(This evening through Sunday)
Issued at 242 PM CDT Sat Mar 16 2024
A low pressure system will continue sitting across the western
U.S. and swing embedded disturbance across our area. As a result,
the overall trend on radar imagery (as of 245 PM CDT) has been
scattered rain showers that occasionally intensify. One or two
thunderstorms did develop, and they briefly produced small hail.
We expect this trend to continue with what`s left of the activity
as it dissipates over the next hour or two (by 5 PM CDT).
Then for tonight, after midnight, the HRRR shows a batch of
thunderstorms developing south of I-10. Some of this activity may
be a bit stronger and may be capable of producing large hail (1"
in diameter). In fact, the Storm Prediction Center has this area
outlooked for a Marginal Risk of severe weather with large hail
being the main hazard. The better coverage for these stronger
thunderstorms will probably be further to the south of Kimble,
Sutton, and Mason Counties. A brief period of locally heavy rainfall
cannot be ruled out completely.
Afterwards, this area of rain will weaken and move northward through
Sunday morning. The I-10 corridor and the Concho Valley are the most
likely locations that will see the best coverage. Small hail and
lightning will be the main concerns with most of this activity at
this point. Patchy fog will also develop overnight similar to what
we saw today.
&&
.LONG TERM...
(Sunday through Friday)
Issued at 445 AM CDT Sat Mar 16 2024
The wet, gloomy, and cloudy pattern looks to continue through
Monday. Cold high pressure moving through the central Plains should
keep northeast surface winds in place, while an upper-level low over
the the Desert Southwest will continue to generate cloud cover
across west Texas. However, rain chances should start to diminish
as the best mid-level energy to generate precipitation should remain
confined across the Permian Basin and Edwards Plateau. The surface
high should settle along the Gulf Coast by Tuesday. This should
allow southwest surface winds to start ushering in warmer
temperatures by Tuesday. The forecast picture gets a bit murky for
Wednesday and Thursday as the upper low could become swept up into
the predominant flow and push across Texas. This would generate
additional rain and thunderstorm chances for the area, although
rainfall amounts still look low at this time. By the weekend,
shortwave ridging should set up across west Texas, allowing for
skies to clear out and rain chances to end and temperatures to warm
into the low 80s.
&&
.AVIATION...
(00Z TAFS)
Issued at 632 PM CDT Sat Mar 16 2024
The ongoing IFR to LIFR conditions will prevail through the
overnight hours tonight and into Sunday morning. Rain showers,
thunderstorms, and some patchy fog will cause all terminals to see
low ceilings and some reduced visibilities through the TAF period.
Marginal Risk of severe weather remains in place across the KBBD
and KJCT terminals, with some hail possible with the isolated
thunderstorms that can develop through the period. Otherwise,
expect fog to redevelop overnight (area wide) adding to the IFR to
LIFR conditions.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 49 61 44 62 / 30 40 20 0
San Angelo 50 59 45 62 / 50 60 20 10
Junction 53 64 45 63 / 70 70 20 10
Brownwood 52 62 45 62 / 40 40 20 0
Sweetwater 49 57 44 60 / 20 40 20 0
Ozona 52 59 45 59 / 70 90 40 30
Brady 53 60 46 59 / 60 50 20 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...41
LONG TERM....SK
AVIATION...TP
Area Forecast Discussion
National Weather Service Las Vegas NV
731 PM PDT Sat Mar 16 2024
.SYNOPSIS...Isolated to scattered showers will continue to
spiral around a low pressure system over Arizona through tonight.
The low pressure center will continue to meander over Arizona
through Tuesday. This will lead to the continued chance for showers
and slight chance for thunderstorms around the higher terrain. As
the low slowly weakens through mid-week temperatures will return to
above normal.
&&
.UPDATE...Scattered showers and isolated thunderstorms developed
this afternoon under the center of a closed low that continues to
sit over western Arizona. As the sun set and the limited instability
diminished, radar showed this precipitation dwindling in the past
hour. Further north in Lincoln and Nye COunty, a band of light rain
continued to rotated west around the edge of the low as vorticity
advection allowed for precipitation to persist past sunset. No
impacts were reported this afternoon with any of the precipitation
other than a few outflows that gusted to around 30MPH in southern
Mohave County. Precipitation was light and convection was limited.
The overnight forecast looks good and only minor updates were
needed. THe precipitation associated with cold core dynamics will
continue to diminish in Clark and Mohave counties, ending in the
next hour or two. The band of precipitation in Lincoln County will
continue to rotate cyclonically through southern Nye, southwest Inyo,
and central San Bernardino counties through the night. Precipitation
amounts will be light and no significant impacts are expected.
Outside of this precipitation, it should be a quiet night. Clouds
will keep overnight lows fairly warm as they have the past few
nights. Not expected fog at this time and none of the ensembles show
probabilities over 15% for reduced visibilities. Current RH values
remain around 50&-70% and precipitation today has been light so its
not overly saturated at the surface (which is confirmed on forecast
soundings through the night). However, forecasting fog in the
desert is tough- models struggle since its rare. The overall set up
doesn`t suggest fog will develop anywhere, but it will be something
to watch either way for tonight as winds will be light and if any
one spot clears out of the clouds enough- they would quickly drop
to around the dewpoint and saturate.
-Nickerson-
&&
.PREVIOUS DISCUSSION...100 PM PDT Sat Mar 16 2024
.DISCUSSION...Through next Saturday.
Widespread area of light showers that was over Las Vegas early this
morning has moved south across San Bernardino County early this
afternoon. That area will continue to drift south into Riverside
County this afternoon. As it does so, scattered showers and even a
few thunderstorms will develop under the cold pool aloft, which is
more probable over Mohave County. Those thunderstorms will be
capable of producing brief heavy rain and hail. HRRR suggests the
convective showers and thunderstorms under the upper low will
dissipate this evening. However, conveyor belt of moisture wrapping
around the north-side of the low will keep some light showers moving
west across Lincoln, Nye, Clark and Inyo County this evening and
overnight. Any additional accumulations of snow in our mountains
will be an inch or less so decided to cancel the winter headline.
Latest guidance keeps this pesky cutoff low meandering over Arizona
through Tuesday. Even as the low slowly fills, there will be a
slight chance (10-20%) to low-end chance (30%) for showers and a few
thunderstorms to develop primarily over the higher terrain of
northwest Arizona, southern Nevada, and eastern California each day.
Once the low finally opens up and starts moving east Wednesday, the
Great Basin and Mojave Desert will lie under a ridge of high
pressure Thursday and Friday. More uncertainty next weekend with
timing and depth of trough approaching the area.
Temperatures will rise to above normal values mid-late week while
some breezes likely increase with the approaching trough.
&&
.AVIATION...For Harry Reid...CIGs are expected to improve through
the rest of the afternoon and evening, reaching BKN 8-10kft by the
late afternoon. Isolated showers or thunderstorms may develop this
afternoon, but confidence is low in storms reaching the terminal.
Clouds will continue to clear becoming SCT 10kft by Sunday morning.
Northeasterly winds with speeds of less than 10 knots will shift to
the southwest after sunset, taking a more westerly direction in the
early morning hours. Winds switch back to the northeast tomorrow
morning, following a diurnal pattern. Speeds remain less than 10
knots throughout the forecast period.
For the rest of southern Nevada, northwest Arizona and southeast
California...Rain bands move out of San Bernardino and Mohave
counties this afternoon. Isolated showers or thunderstorms may
develop this afternoon, but confidence is low in storms reaching any
of the terminals. Afterwards, dry conditions are anticipated at all
TAF sites tonight and tomorrow. For the rest of today and tonight,
winds remain under 10 knots at all TAF sites except for KBIH, where
northerly winds between 10 and 15 knots are possible. Tomorrow
afternoon, winds increase out of the north along the Colorado River
including KIFP and KEED, with speeds reaching over 10 knots. Diurnal
winds with speeds under 10 knots are expected elsewhere. Ceilings
will improve through the rest of the day and tonight. Mid and high
clouds remain tomorrow.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
DISCUSSION...Pierce
AVIATION...Meltzer
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