Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/14/24
Area Forecast Discussion
National Weather Service Hastings NE
629 PM CDT Fri Sep 13 2024
.KEY MESSAGES...
- Above-normal temperatures expected to persist through at least
next week with highs in the 80s.
- We could see a few sprinkles late tonight (after midnight)
lasting into Saturday morning, but most locations will remain
dry or just see scattered trace amounts.
- Small chances for showers and thunderstorms begin Sunday night
through Monday night (20-30%) as large western upper trough
nears our area.
- Better chances for showers and thunderstorms are expected off
and on Tuesday night through Friday (30-50%) with upper storm
system nudging further east and closer to our region. Warm for
this time of year (80s) all of next week on the warm side of
the large upper trough.
&&
.DISCUSSION...
Issued at 359 PM CDT Fri Sep 13 2024
Tonight through the Sunday...
The remnants of Hurricane Francine will continue to spin around
the Arkansas to Alabama area moving very little, but gradually
weakening with time. Some of the high clouds from Francine have
made their way as far northwest as Iowa today and could sneak
back west into some of our eastern counties later tonight into
Saturday morning. We could see a few isolated sprinkles late
tonight into Saturday morning, but most locations should remain
dry.
Several runs of the HRRR model indicate that there could be
patchy shallow fog development early Saturday morning just to
our east across southeastern Nebraska, but will keep fog mention
out of our forecast for now as the winds will remain just a
little stronger across our forecast area preventing fog
formation.
The warm weather will continue this weekend and beyond with
Saturday probably being one of the cooler days of the 7 day
forecast, but only by a few degrees. Highs Saturday will be
in the lower 80s for most locations with mainly mid 80s expected
for most of the rest of the week.
Monday through Friday...
A large upper trough will deepen across the western United
States at the start of the week and then remain through the
week being reinforced by several different shortwaves as the
week progresses. The first chances for thunderstorms begin
Sunday night. However, the better chances for thunderstorms
will probably hold off until mid to late week as the upper
trough tries to edge further east (Tuesday Night/Thursday night
into Friday). At this point the NBM precipitation chances are
only 30-50 percent, but I expect these will go up for at least
certain time frames as timing of the embedded shortwaves becomes
more clear.
The entire region will continue to see above normal temperatures
(highs in the 80s) with warm/moist flow expected ahead of this
upper trough. Given the strength of this upper trough we may
even have to watch out for the possibility of some severe
weather late week somewhere in the central plains, but too early
to pinpoint just when and where.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 622 PM CDT Fri Sep 13 2024
For KGRI/KEAR Airports:
Southeasterly winds are expected through the TAF period,
diminishing to around 5 kts overnight then increasing again to
around 10 kts during the day Saturday. Some mid- and high level
clouds are expected through the period, mainly at 5k to 7k ft
AGL for the mid-level clouds and 20k to 25k for the high level
clouds. Most cloud cover will remain VFR, although models do
indicate a 20-30% chance of MVFR conditions between 11Z and 15Z
Saturday morning. A few sprinkles may be possible along with the
lower cloud deck but confidence remains low regarding that.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Wesely
AVIATION...Hickford
Area Forecast Discussion
National Weather Service Goodland KS
637 PM MDT Fri Sep 13 2024
.KEY MESSAGES...
- Above normal temperatures will continue through the end of
next week.
- The weather pattern becomes a bit more active Monday through
Tuesday with increasing wind and only 20%-30% chances for
showers/thunderstorms.
&&
.UPDATE...
Issued at 632 PM MDT Fri Sep 13 2024
Introduced some slight chance pops for portions of SW Nebraska
as some showers and storms may develop in the next hour or two.
Latest radar trends show two boundaries approaching each other
near the Cheyenne/Rawlins border. This area is also favored
according to RAP 700-500 mb to have some moisture available
which is seen with a strip of cloud cover. 23Z run of the HRRR
as well supports some convection developing. Should this occur
perhaps some gusty winds would be the primary hazard with any
shower or storm. RAP 700-500mb moisture does move the favored
moisture out of the CWA by 03Z so a relatively short time range
for rainfall will occur. Have also added in some silent pops for
northeast portions of the area around sunrise as mid level
moisture does increase again. May have to watch for some patchy
fog across eastern portions of the area (Graham/Norton counties)
around sunrise as moisture advection in the form of an easterly
winds occurs.
&&
.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 135 PM MDT Fri Sep 13 2024
Tonight...there is some disagreement between the models as to how
much or little moisture will be available to continue the previous
forecast mention of showers/thunderstorms across the northeastern
and eastern parts of the forecast area this evening. The GFS model
is showing more moisture being available in the 850-500mb layer when
compared to just about every other model. Per coordination with
surrounding offices, we`re going to remove the prior forecast of 20%
chances for thunderstorms. Low temperatures are forecast to be in
the lower 50s to around 60.
Saturday-Saturday night...there is perhaps just enough moisture in
the 700-500mb layer to support the previous forecast mention of a
20% chance for thunderstorms across the northwest corner of the
forecast area in the afternoon. High temperatures are forecast to be
in the middle 80s with low temperatures in the middle 50s to lower
60s.
Sunday-Sunday night...500mb flow backs to the southwest, ahead of a
large and deepening low pressure area forecast to be over central
California around 12z Monday. South/southeasterly winds will begin
to increase and reach the breezy to perhaps windy category during
the day, continuing for many through the night. High temperatures
rise a few degrees into the upper 80s to lower 90s. Low temperatures
are forecast to be in the middle 50s to middle 60s. With increasing
moisture in the 700-500mb layer periodically moving across the area
from the southwest, there will be a 20-30% chance for thunderstorms
during the night. Additionally, there are signs from the GFS/NAM
boundary layer relative humidity forecasts that the northeast 1/2-
1/3 of the forecast area could have stratus and perhaps some fog
move in from the southeast after midnight.
Monday-Monday night...any morning stratus should burn off before
afternoon. High temperatures are forecast to be in the middle 80s to
lower 90s with low temperatures in the upper 50s to middle 60s.
Presently, the large upper level low in central California in the
morning is forecast to be over northwest Utah/southeast Idaho by 12z
Tuesday with upper level ridging over the plains states. Presently,
despite NAM/GFS 700-500mb forecasts of modest moisture being
available for showers/thunderstorms for some during the afternoon
and overnight hours, the currently forecast has them limited to east
of Highway 25 in the afternoon then again after midnight. I expect
this to change as we get closer in time. Southerly winds gusting 25
to 35 mph are forecast for the daytime and overnight hours.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 109 PM MDT Fri Sep 13 2024
An eye on storm potential Tuesday afternoon into evening. A broad
mid-level trof W against a E CONUS blocking pattern, subsequent S
flow maintenance pumping higher thetaE air northward keeps moisture
prevalent over the region early in the week. An eye on the steering
flow and whether moisture associated with Ileana, presently off Baja
Mexico, get usurped northward. With greater moisture availability
out ahead of an anticipated sharpening dryline, Tuesday could see
the potential for severe weather.
So for Tuesday, a disturbance rotates through the broad H5 trof N
invoking a localized negative-tilt and mid to upper level diffluence
across the N Plains. Yet this and accompanying jet max retrogrades
westward into the Rockies with occlusion. Main surface low over MT
with a secondary low across NE CO parent with a dryline, this will
be the focus for our area with shower and thunderstorm chances. An
enhancement in dry southwesterlies rearward, with higher
dewpoint air and favorable instability out ahead, there is
potential focus for active weather along a possible dryline
bulge in the southwest NE vicinity. Uncertain bulk shear
outcomes, perhaps with boundary layer decoupling shear profiles
enhance in support of sustained up- drafts and storm
development. Better focus looking to be N&E of the Goodland-
Imperial region. Expect daytime strong southerly winds 20- 25
mph sustained with gusts 30-50 mph diminishing overnight. Along
with the dryline, will need to watch locations west of the line
for <25% RH as to fire weather concerns. Per local research,
wind speeds and 0-2 km lapse rates signal the possibility for
some blowing dust yet with daytime heating lapse rates will
likely deepen beyond 2 km throwing doubt. Still deserves
monitoring especially with any storm development.
Wednesday onward, between a series of retrograding westward tropical
disturbances over the E CONUS within the broader, wobbling, blocking
pattern subsequent against a continued broad trof across the W CONUS
through which disturbances rotate, there`s a lot of uncertainty with
the forecast. Consensus would point to a quiet midweek period with
rising mid-level heights and suppressed activity ahead of series of
disturbances ejecting northward across the region towards late week
into the weekend. Signals of perhaps the stagnant pattern breaking
down, evolving eastward would yield better precipitation chances in
the future beneath favorable cyclonic, diffluent flow. Chances are
slight for now given the uncertainty.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 445 PM MDT Fri Sep 13 2024
VFR conditions remain forecast for the period. A slim,
conditional chance of showers or storms does exist near the Red
Willow/Norton/Furnas vicinities through 02Z with a front as the
source of lift. However with meager mid level moisture I would
put the chance at less than 5% of occurring so will leave out of
the TAF but will watch closely. Another LLJ develops this
evening leading to another night of LLWS at each terminal. Winds
will become easterly as some moisture begins to stream back into
the area. May need to watch for some stratus or fog at KMCK
around sunrise but current guidance suggest it will stay a row
or two of counties away from the terminal. Will reevaluate for
the 06Z TAF issuance.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
UPDATE...Trigg
SHORT TERM...99
LONG TERM...Sipprell
AVIATION...Trigg
Area Forecast Discussion
National Weather Service North Platte NE
641 PM CDT Fri Sep 13 2024
.KEY MESSAGES...
- Isolated to scattered thunderstorms possible each evening through
the weekend with temperatures holding at near or slightly above
normal levels
- Stronger winds return Monday and Tuesday, but humidity should
remain well above critical fire weather thresholds
- Cool front may bring widespread thunder activity later Tuesday
into Wednesday
&&
.SYNOPSIS...
Issued at 359 PM CDT Fri Sep 13 2024
Nebraska lies on the periphery of an upper trough digging into the
northern Rockies and Plains, with the accompanying low spinning over
Saskatchewan. Meanwhile, the remains of Francene are centered over
the Mississippi Delta and an upper ridge holds over the Great Lakes.
This pattern places Nebraska in primarily southwest flow aloft. At
the surface, a deeper low is stacked under the primary upper low
just north of the MT/Sask border, and a cool front stretches from
there to a secondary low stationed in the Sandhills. As of 20z, the
front lines up roughly along Hwy 83, with mainly dry northwest low
level flow behind it and relatively moist south/southeast flow out
ahead. The cumulus field has been building along and ahead of the
front, with the greatest convergence noted in north central Neb from
near BBW to ANW.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 359 PM CDT Fri Sep 13 2024
This evening into tonight... The main forecast challenge concerns
potential thunderstorms ahead of the cool front. Kept schc PoP from
previous forecast, but trimmed coverage to be mainly confined to
north central Neb. Very little model guidance suggests development
to the south, which appears to have a stronger cap in place per SPC
RAP Meso. Moisture transport at H85 also indicates greater advection
and convergence to the north on the eastern gradient of stronger
shear and instability. Nonetheless, surface dew point depressions
remain 25+ and overall CAPE/lapse rates are marginally supportive of
stronger convection. Any thunder should be isolated in coverage, or
scattered at best, with 00-06z being the most conducive timeframe.
Investigated the potential for fog and/or stratus with generally
light southeast low level flow in place overnight. Think the greater
potential lies east of the forecast area where isentropic upglide is
steeper within the moist layer and SREF probabilities are greater.
Can`t completely rule out patchy fog in the the usual spots in the
Platte River and lower Loup Valleys, but confidence in significant
impacts is low. Left fog mention out of the forecast for now. As for
min temps, stayed near the middle of the relatively small NBM
envelope, which trend toward the warmer numerical guidance. Felt it
seemed reasonable given consistent southerly low level flow
overnight and (very) weak warm air advection compared to last night.
Values range from near 50F along the Pine Ridge to upper 50s far
southwest and central.
Tomorrow... The Western US upper trough lifts somewhat,
transitioning the flow aloft to more broad southwest or bordering on
quasi-zonal for Nebraska. The surface cool front may retreat west
into the panhandle, which will allow for more widespread
south/southeast low level flow to continue. Temp advection at H85
weakens further and becomes negligible across most of the Sandhills.
Again used guidance near the NBM median for highs in the mid 80s,
which closely reflects today`s conditions. CAMS suggest a greater
potential for convective development tomorrow afternoon ahead of the
front. Some solutions hint at a small linear system or complex
following the Hwy 20 corridor. Increased chc PoP across the northern
Sandhills, which will likely lie toward the nose of higher CAPE with
supportive deep layer shear. A ribbon of nearly 2000 j/kg MUCAPE
stretches across western Neb, while mid-level lapse rates approach 8
C/km during the afternoon. Timing of the most widespread precip
doesn`t seem to correspond with the best severe parameters though,
with greater potential occurring after 00z when instability and
shear decrease.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 359 PM CDT Fri Sep 13 2024
For the start of the new week, the upper trough amplifies again as a
closed low follows the NW Pac coast and emerges onto the Great
Basin. Longer range guidance pushes the low back north from there,
placing it in Montana by midweek. This pattern places Nebraska
squarely in southwest flow and nearly meridional midweek. Another
cool front approaches the forecast area as the upper low passes to
the west, and then a surface low may sit over the Sandhills toward
late week. All in all, low level flow will be steady out of the
south and be nearly uninterrupted from the Gulf. A steepening
pressure gradient and strengthening H85 flow should result in
stronger winds Monday and Tuesday. At this time, humidity should
hold well above critical thresholds. Despite the limited threat of
official red flag conditions, the environment may still be conducive
for rapid fire spread, especially in areas with thick cured fuels.
Dew points should rise into the 60s, helping to aid additional daily
thunder chances. The best potential for precip comes late Tuesday
into Wednesday with the cool front passage and a stout mid-level
shortwave rounding the trough. Temperatures also remain near or
above normal levels through midweek with highs generally in the
mid/upper 80s and lows in the 60s.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 641 PM CDT Fri Sep 13 2024
VFR conditions will continue to prevail across all of western
and north central Nebraska tonight and Saturday. An area of
cloud ceilings around 7000 FT AGL will continue this evening at
KLBF, KANW, KBBW and KONL and should gradually become FEW-SCT
overnight. Isolated showers and storms are possible tonight,
mainly east of the KLBF and KVTN terminal and have not included
a mention attm.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Snively
SHORT TERM...Snively
LONG TERM...Snively
AVIATION...Roberg
Area Forecast Discussion
National Weather Service Midland/Odessa TX
640 PM CDT Fri Sep 13 2024
...New AVIATION...
.SHORT TERM...
(This afternoon through Saturday night)
Issued at 147 PM CDT Fri Sep 13 2024
Per latest water vapor imagery and RUC analysis, the remnants of
Francine continue to churn slowly northward across the Lower
Mississippi Valley, with an associated fetch of moisture streaming
northward around a ridge of high pressure centered over the Great
Lakes. To the north and west of the region, a trough continues
slowly drifting eastward across the Great Basin, while to the
southwest, Tropical Storm Ileana is taking shape over Baja
California Sur. Over Southeast New Mexico and West Texas, low-
amplitude ridging has developed, aiding our continued warming
trend, which will result in our hottest temperatures of the week
this afternoon. Highs are on target to top out in the middle to
upper 90s for most, with lower 100s along the Pecos and Rio Grande
Valleys as well as across the northeastern Permian Basin. The
rainfall received last week has aided in increasing soil moisture,
which seems to be our saving grace from getting as hot as we
otherwise would. That said, Midland`s forecast high today is 99F,
and the record for today stands at 102F set back in 1930, so the
record will be safe for another year. Otherwise, subsidence will
maintain dry conditions areawide, which will continue through
tonight as lows drop into the 60s and 70s across the area.
Saturday will see the beginning of a slow, gradual cooldown as the
aforementioned ridge over our area dampens and shifts eastward,
with decreasing thicknesses allowing for temperatures at least a
couple degrees cooler than today for most. Highs across the plains
will generally be in the middle to upper 90s, with upper 80s and
lower 90s in the mountains, and 100s much more localized along
portions of the river valleys and the far northeastern Permian
Basin. Saturday afternoon, a fetch of subtropical moisture will
begin to edge into southern portions of the area, and given
decreasing subsidence and ample insolation, thunderstorm chances
return for areas mainly along and south of I-10. While potential
remains low (10-30%) and storms will largely be isolated in
nature, the best chance will be across the Big Bend, gradually
decreasing northward across the Davis Mountains to the I-10
corridor. That said, storms that develop will be capable of
producing lightning strikes and gusty winds, as well as brief
downpours. Thus, those with outdoor plans tomorrow afternoon will
need to stay weather aware, and have a plan for shelter if
lightning or thunder are observed. Storms that develop will
diminish fairly quickly after sunset, with a quiet night then
ahead with lows in the 60s and 70s for most, and 50s across the
Davis Mountains and Marfa Plateau.
JP
&&
.LONG TERM...
(Sunday through Thursday)
Issued at 147 PM CDT Fri Sep 13 2024
Our area remains a rock stuck in a hard place. To the east, the
remnants of Francine remain nearly stationary over the Southeast
with a strong upper-level high pressure over the Great Lakes
region. To the west, persistent large-scale troughing remains in
place and blocked by the Great Lakes high. The southern Great
Plains is somewhere in the middle with a modest ridge axis in
place from northeastern Mexico into east Texas. Unfortunately,
little change is expected to close out the weekend and through
most of next week.
Temperatures each afternoon remain nearly stationary day to day
with above normal temperatures in the 90s for the majority of
locations. Night-time temperatures remain above normal in the
upper 60s and lower 70s as well. Skies should continue to be
mostly sunny or mostly clear with only occasional passing clouds
each day.
Rain chances are slim to none with little exception. One exception
is possible early next week. A shortwave trough within the
longwave trough over the western CONUS quickly digs then lifts
across the central Rocky Mountains. Are region remains far removed
from the greatest forcing with this passing system, but with
convective temperatures likely to be breached, even nebulous
forcing may be enough for a slight chance of rain. Until the
western trough begins its march to the east towards the end of
next week, we remain largely high and dry.
-Chehak
&&
.AVIATION...
(00Z TAFS)
Issued at 635 PM CDT Fri Sep 13 2024
VFR conditions will continue the next 24 hours. Winds will
remain southerly to southeasterly tonight with intermittent gusts
expected to continue this evening before diminishing. Some
variability is possible late tonight as winds become lighter,
particularly at CNM and PEQ, though winds once again settle out of
the southeast areawide on Saturday. High clouds will gradually
increase from south to north through the period, with a scattered
cumulus deck around 7-8kft forecast to develop after 18Z. There
is a low potential (10-20%) for thunderstorms Saturday afternoon,
mainly impacting PEQ and FST, though low probability and
uncertainty in timing precludes mention at this time. Potential
impacts would include erratic gusty winds and lightning strikes.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 74 98 70 97 / 0 0 0 0
Carlsbad 68 97 68 96 / 0 0 0 0
Dryden 74 97 72 96 / 0 20 0 0
Fort Stockton 73 96 69 95 / 0 10 0 0
Guadalupe Pass 70 90 67 87 / 0 0 0 0
Hobbs 68 96 67 93 / 0 0 0 0
Marfa 59 90 56 89 / 0 20 10 10
Midland Intl Airport 74 97 70 94 / 0 0 0 0
Odessa 73 96 73 94 / 0 0 0 0
Wink 72 99 72 97 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
TX...None.
NM...None.
&&
$$
SHORT TERM...84
LONG TERM....91
AVIATION...84
Area Forecast Discussion
National Weather Service Marquette MI
804 PM EDT Fri Sep 13 2024
.KEY MESSAGES...
- Low chances (15-40%) for showers and storms Saturday afternoon
through Sunday, mainly over the west half. Otherwise, the prolonged
dry stretch will continue into much of next week.
- Extended stretch of above to well above normal temperatures continues
through the forecast period with highs mainly in the upper 70s and
80s.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 301 PM EDT Fri Sep 13 2024
GOES-16 Day Cloud Phase RGB imagery shows clear skies over the
UP today with some low stratus over the northern portions of
western Lake Superior and some high cirrus streaming towards the
western UP associated with the remains of Hurricane Francine.
RAP analysis shows a 590 dam ridge over much of Michigan
contrasted by troughs of 577 dam associated with Francine`s
remnants over Arkansas and 555 dam over southern Saskatchewan.
By 12Z Sunday morning, global model agreement is good in
troughing remaining over the southeast with the ridge shifting
over the Lower Great Lakes while the Canadian Prairie troughing
lifts north. This leaves the UP under mainly stable SW flow
aloft, leading to continued above-normal temperatures and a lack
of precipitation. GFS LAMP guidance has trended downwards
throughout the day in the probabilities of fog overnight, though
the 12Z HREF is more confident in fog with around 50%
probability of visibility falling to 1/2SM by 12Z. Interior UP
Tds today have mainly followed the 10th percentile of the NBM,
casting doubt on the availability of moisture for fog overnight.
This forecast will reflect no fog, but it would not be
surprising if a repeat from previous nights occurred again given
the stagnant airmass.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
Issued at 349 PM EDT Fri Sep 13 2024
The weather story of Upper Mi will remain essentially unchanged this
weekend into next week as anomalously strong ridging generally
remains anchored from eastern Canada through the Great Lakes and
northeast U.S. leading to mostly dry weather and above to well above
normal temperatures through the period.
Models indicate that a shortwave now over the Northern Plains could
combine with remnants of Francine over the Central and Lower MS
Valley region as it lifts northeast up the backside of the amplified
ridge into the Upper Great Lakes on Saturday. Weak forcing/
instability along with positive theta-e advection associated with
this feature could lead to isolated to scattered showers late
Saturday into Sunday morning over mainly the western half of the
U.P. With fcst soundings revealing a few hundred j/kg of elevated
CAPE a rumble or two of thunder can`t be ruled out either. A few of
the models have another weak shortwave rippling through the mid-
level ridge on Monday, but with 500 mb heights already expected to
rebound after the weekend shortwave and fcst soundings showing
drying at mid-levels I`d venture to guess that Monday`s shortwave
won`t have much impact other than maybe an increase in mid and high
clouds.
As the mostly dry weather continues into the middle and latter end
of next week under amplified ridging, wildfire concerns could mount
as fuels dry out. Fortunately, through much of the week it looks
like minimum RH values will stay above elevated thresholds (40 pct
or higher) and winds will stay generally light with gusts 15 mph or
less to keep fire weather concerns at a minimum.
As for temps, 850 mb temps of 15C to as high as 18C under mostly
sunny to partly cloudy skies should yield max temps most days
ranging from the upper 70s to mid 80s across much of the forecast
area. These readings are generally 10-15F above seasonal normals for
mid-September.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 804 PM EDT Fri Sep 13 2024
VFR will be the prevailing flight category, but will now add mention
of at least MVFR fog at CMX early Saturday morning. Light
southeasterly winds continue.
&&
.MARINE...
Issued at 349 PM EDT Fri Sep 13 2024
Light winds of 20 knots or less will continue across the lake this
weekend through next week as high pressure ridging holds on over the
Great Lakes. However, some shortwaves could bring isolated to
scattered showers and maybe an isolated thunderstorm to western
portions of Lake Superior Saturday through Sunday and possibly again
on Monday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...GS
LONG TERM...Voss
AVIATION...TDUD
MARINE...Voss
Area Forecast Discussion
National Weather Service New York NY
1038 PM EDT Fri Sep 13 2024
.SYNOPSIS...
High pressure remains in control through early next week. An area
of low pressure and associated frontal system may impact the
area mid to late week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
No significant changes to the forecast for this update.
A mid level shortwave trough passes off the New England coast
this evening with a really weak surface reflection moving
across the area. However, this will be the start of an
anomalously strong upper high(+2SD) from the Great Lakes into
Canada to build east and into the area this weekend. Thus,
surface high pressure centered east of the area will be replaced
by a strengthening high across eastern Canada into the Northeast.
12Z HRRR and HREF solutions point to a chance of low clouds and
patchy fog again late tonight, mainly across LI and SE CT.
Model soundings show the moisture to be extremely shallow and
may be more of ground fog.
Another night of light winds and good radiational cooling with
lows right around normal, mainly in the upper 50s to lower 60s.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
Any lingering low clouds and fog in the morning will quickly mix
out. Strengthening surface high pressure across eastern Canada
will build south along the New England coast through Sunday. This
will mean a continuation of dry and warm conditions with the potential
for some patchy morning low clouds and fog again in the morning
Sunday.
Highs will generally be in the lower 80s Saturday, with a bit
cooler conditions on Sunday due to an easterly flow cooling the
boundary layer a bit. Highs are forecast to be in the upper 70s
to lower 80s, warmest to the north and west of NYC. Lows Sunday
morning will again be in upper 50s to lower 60s, but closer to
the mid 60s for the NYC metro. Light southeast winds on Saturday
will be replaced by a slightly stronger east flow on Sunday,
most noticeable along the coast.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Tranquil weather will continue through Tuesday night with deep
layered ridging aloft and high pressure at the surface centered off
the Northeast Coast, which slowly drifts east Monday night through
mid-week. The high will protect the region from a slowly approaching
frontal system to the south with an associated slowly strengthening
low pressure system that treks north Sunday night through Monday
night.
Aloft, strong ridge will gradually shift offshore Tuesday through
mid to late week. An upper level trough to the west slowly
approaches the local region during this time, with the operational
ECMWF weaker with this feature compared to the operational GFS and
Canadian models.
At the surface, this translates to a departure of high pressure
farther offshore Tuesday through Friday and a slowly approaching
frontal system from the west. By Wednesday through Friday, rain
showers are forecast. Highest chances relatively speaking are for
more SW parts of the region Wednesday through Wednesday night with
otherwise mostly slight chance POPs.
Temperatures are forecast to remain near normal for daytime highs
but generally above normal for late night to early morning lows.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
High pressure remains centered to our north and east through
Saturday.
VFR much of the period. Possible low stratus and mist
development at coastal terminals late tonight into early
Saturday morning. Confidence in coverage and occurrence remain
low, but maintained a TEMPO for IFR cigs 9Z to 13Z Sat for the
city, KISP, and KGON. LIFR cannot be ruled out during this time
either. Skies clear by mid morning.
Light and variable at most terminals overnight. Flow becomes
light E/SE by mid-morning tomorrow.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
IFR or lower conditions possible Sat AM with possible low
stratus and mist development.
OUTLOOK FOR 03Z SUNDAY THROUGH WEDNESDAY...
Saturday Night-Tuesday: Mainly VFR, but a chance of MVFR or
lower fog/clouds for each late night/early morning.
Wednesday: MVFR or lower with SHRA possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
High pressure will continue to promote a weak pressure gradient with
light winds through tomorrow with sub-advisory conditions. East
winds winds increase a little on Sunday, but remaining below
advisory thresholds.
Seas are forecast to build to 4 to 5 ft seas Monday and continue
into the middle of next week as a low pressure system remains well
south of the area.
&&
.HYDROLOGY...
No hydrologic concerns through next week.
&&
.TIDES/COASTAL FLOODING...
With an approaching full moon for next week on September 17th,
astronomical levels will be rising leading up to that date. With the
continuous easterly flow, this will help build seas and allow for
some piling of water. Winds are expected to remain generally
light, near 10 kt or less. While some of the guidance is showing
waters level increasing, there is general consensus of keeping
them below minor coastal flooding benchmarks. However, this will
likely depend on the development of low pressure off the Carolina
coast early next week.
There is a low risk of rip current development at the ocean
beaches Friday and Sunday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JP/DW
NEAR TERM...DW/MW
SHORT TERM...DW
LONG TERM...JP
AVIATION...MW
MARINE...JP/DW
HYDROLOGY...JP/DW
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Phoenix AZ
405 PM MST Fri Sep 13 2024
.UPDATE...
Updated Aviation
&&
.SYNOPSIS...
Temperatures will continue to cool across the region through early
next week, eventually falling to below normal by Monday. Going into
this weekend, moisture will increase across much of Arizona with
shower and thunderstorm chances expected by Sunday and lasting into
Monday focused across south-central and eastern Arizona. Dry and
mild conditions are then expected starting next Tuesday, lasting
through much if not all of next week.
&&
.DISCUSSION...
A dry, tranquil Friday afternoon is underway as dry west/southwest
flow aloft persists over the region, promoting clear skies across
most of the Southwest CONUS. Near to slightly above normal
temperatures today with highs around 100-105 degrees will cool to
around 99-102 for Saturday before more significant cooling takes
hold later this weekend into next week. Attention this weekend turns
to increasing tropical moisture into the region associated with
Tropical Storm Ileana, which is currently centered over the southern
tip of the Baja peninsula.
Tropical Storm Ileana will help push moisture northward into Arizona
starting this evening and through the weekend, though forecast
soundings indicate that this moisture will primarily be confined to
the low/mid levels with dry air remaining above about 700 mb. As
this moisture increases into the state, a weak shortwave is expected
to move through southern California and into northern Arizona late
Saturday into Sunday. This weak trough may provide enough forcing to
take advantage of the increasing moisture and spark some elevated
showers and isolated thunderstorms going into Sunday morning across
south-central Arizona, which is supported by today`s 18Z HRRR run.
The greatest chances for rain will occur Sunday and into the first
half of Monday as a potent Pacific trough dives down along the West
Coast and into northern California by Sunday evening before pushing
through the Great Basin Monday. Global ensembles support PWAT values
increasing Sunday to around 1.5", which is around 150% percent of
normal for this time of year. Given the expected strong low and mid
level moisture and relatively cool air aloft over much of south-
central Arizona on Sunday, forecast MUCAPEs of 1000-1500 J/kg are
likely over the lower deserts. Despite the large-scale forcing
likely being fairly limited over our area as the trough mostly stays
to our north Sunday into Monday, the available instability should be
plenty to spark off showers and storms Sunday afternoon initially
over any higher terrain areas. A rather quick southwesterly steering
flow upwards of 25-35 kts Sunday into Monday will mean any storms
will be moving at a good clip and thus will limit the residence time
of any storms dumping heavy rainfall over a given area. However, any
training of storms could be enough to cause heavier rainfall amounts
of greater than one inch, potentially leading to some localized
flooding issues. A few strong to severe storms can also be expected
on Sunday given the expected good instability and bulk shear between
25-35 kts.
Dry air is expected to remain focused to the west of Maricopa County
through the first part of Monday with PWATs generally along and west
of the Lower Colorado River Valley remaining under an inch during
this time. A few rounds of showers and storms are likely to impact
locations across south-central Arizona into eastern Arizona through
Monday afternoon before the drier air surges northeastward through
the area by Monday evening. The best timeframe for rain still looks
to fall between Sunday afternoon and Monday afternoon with any
stronger storms likely occurring during the daytime hours when
DCAPEs will be maximized. The latest WPC`s QPF amounts have trended
upwards a bit closer to 0.50-0.75" across the lower elevations of
south-central Arizona with amounts quickly dropping off across
western Maricopa County and points to the west. The greatest totals
look to remain across favored orographic features north and east
of Phoenix with amounts in excess of 1" possible across northeastern
Maricopa County and southern Gila County and thus could lead to some
burn scar flooding issues. If we end up seeing some training storms
across the area, some places could see locally heavier 1-2"+
amounts.
While dry conditions will persist across the western CWA, a cold
front will push through southern California during the latter part
of Monday, which will act to increase winds across southeast
California, particularly Imperial County. ECMWF EFI indicates
anomalously strong winds increasing across southeast California
during this time with EPS members suggesting gusts reaching wind
advisory thresholds for portions of Imperial County.
High temperatures will continue to slowly drop across south-central
Arizona over the next few days with readings finally dropping into
the upper 90s by Sunday. Highs over the western deserts will not
change all that much through Sunday with readings staying around 100
degrees each day. The main push of cooler air will not arrive until
early next week with highs finally dropping down well into the 90s
on Monday across the western deserts and on Tuesday over the south-
central Arizona lower deserts. Well below normal temperatures are
expected during the middle part of next week with highs bottoming
out on Tuesday and Wednesday in the upper 80s and lower 90s.
Forecast lows will also plummet starting Monday night with lows into
the 50s across the western deserts to the 60s across much of the
south-central lower deserts. The below normal temperatures next week
are likely to persist through at least the rest of the work week,
but model guidance eventually shifts the weather pattern toward weak
ridging and near normal temperatures by next weekend.
&&
.AVIATION...Updated at 2305Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Uncertainty with respect to timing of wind shifts will be the only
weather issue through Saturday evening under a gradual increase in
FEW-SCT midlevel decks. W/SW winds should prevail through the
evening with the switch to easterly likely slightly later than
experienced the past couple days. While a switch back to W will
occur at some point Saturday afternoon, confidence is very low
whether this will occur earlier in the afternoon, or be delayed
until late afternoon. There may be a prolonged period from late
morning through mid afternoon of highly variable directions, though
speeds should remain below 10kt.
Southeast California/Southwest Arizona including KIPL and KBLH:
No weather concerns will exist through Saturday afternoon under
clear skies. Winds will favor a SE component at KIPL and S at
KBLH though periods of variability or nearly calm conditions should
exist overnight.
&&
.FIRE WEATHER...
The weather pattern will shift through the weekend as moisture
increases and a weather system approaches the region. Much lighter
winds are expected today and Saturday with more of a southerly
component quite common and any gusts generally less than 20 mph.
MinRHs will improve to around 15% this afternoon and then 20-25% on
Saturday. By Saturday night, rain chances will begin across portions
of southern Arizona before chances for showers and storms greatly
increase across all of south-central Arizona on Sunday. CWR increase
to between 30-50% across much of south-central Arizona Sunday
through the first part of Monday before drier conditions push
through the area by Monday night. Below normal temperatures are
expected beginning Monday with MinRHs gradually lowering back into
the teens by Wednesday.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Smith/Kuhlman
AVIATION...18
FIRE WEATHER...Kuhlman