Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/04/24
Area Forecast Discussion
National Weather Service Columbia SC
816 PM EDT Thu Oct 3 2024
.SYNOPSIS...
An upper ridge across the southeast today will gradually shift
to the east and south overnight into Friday. Surface high
pressure over the Northeast and Mid-Atlantic will build into the
area for the weekend. Temperatures remain near or above
seasonable values through the weekend.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Key Message(s):
- Patchy fog possible towards daybreak, especially north and
east of Columbia.
Skies are mainly clear across the forecast area this evening but
latest satellite imagery shows clouds moving in from the south
and west. Expect mostly clear to partly cloudy skies to develop
later tonight. The cloudiness will help to dampen fog chances
Friday morning. The best chance of patchy fog will be north and
east of Columbia in addition to normally fog prone locations.
It is not expected to be as widespread as last night. Lows
tonight will be in the mid-60s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Key Messages:
- Quiet and warm weather expected to continue
The mid and upper level flow will become more zonal across the
Southeast through Saturday. At the surface, high pressure over
New England and the Mid-Atlantic will settle in across the
region over the weekend. A weak shortwave will push through
west/southwest flow and mainly to our west, bringing an increase
in cloudiness particularly on Friday. Although the s/w is very
present, the airmass looks to be rather stable with little omega
and increasing PW values to around 1.5" to produce any light
rain showers. There will be little change in airmass into
Saturday but upper level flow will become more westerly with
winds at H5 becoming north to northeast. This should bring in
drier air but also keep daytime temperatures in the low to mid
80s. Overnight lows will remain unseasonably mild with lows in
the lower to middle 60s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Key Messages:
- Relatively high confidence in a quiet period as the storm track
remains north and south of the region
- Cooler temperatures after Tuesday with a change in airmass
Deterministic and ensemble guidance is in good agreement
early next week that conditions should remain rather quiet. An
upper trough will situate to our north, while the Gulf of Mexico
starts to get a bit more active. This trough should line up
nicely with the disturbance to our south and help to keep it out
of our area, instead impacting portions of Florida Sunday
through Monday. Highs should be in the mid to upper 80s with
lows in the mid 60s. Otherwise, the next big shift comes Monday
into Tuesday, with the passage of a cold front which may feature
a few showers, but confidence remains low on any showers at this
time. The new airmass will be cooler and drier, with daytime
temperatures in the 70s and PWATs falling below 0.5". Strong
high pressure is forecast to build into the region behind the
cold front Wednesday through the remainder of the week. The
drier and cooler airmass will provide pleasant overnight
temperatures, just below normal in the lower to middle 50s.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR conditions expected for most of the period. MVFR fog
possible late tonight and early Friday morning.
Surface and upper ridge over the area. The upper ridge will
shift southeast as a mid level trough approaches from the west.
Satellite is showing low and mid level clouds near Savannah and
mid level clouds approaching from west central GA. The latest
HRRR indicates clouds near Savannah will spread north overnight,
while the clouds in GA will push east. Guidance has backed off
on the fog late tonight with NBM restrictions mainly north of
and east of CAE where less clouds are expected. Raised tempo
visibility restrictions to MVFR at sites. Mid level ceilings
developing after 12z Friday with winds east-northeast 5 to 10
knots.
&&
.HYDROLOGY...
Key Message:
- Flood warnings continue along the Congaree and Wateree Rivers
although rivers have crested. River levels will continue to
fall through Friday and into the weekend.
While the rivers are receding, it will take a few more days for
the rivers across the Midlands and CSRA to return to more
normal flows. Those working around area rivers and creeks are
urged to monitor levels and use caution near flooded areas. With
such high flows during the flood event there is lots of debris
in the area lakes and rivers that may be unseen hazards.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$
Area Forecast Discussion
National Weather Service State College PA
1027 PM EDT Thu Oct 3 2024
.SYNOPSIS...
* Valley fog redevelops overnight; clouds and a stray shower
possible over east-central PA later Friday and Friday night
* A great start to the first weekend of October; rain showers
return from NW->SE later Sunday through Sunday night
* Drying out and cooling down next week with frost risk
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
Fog has begun to fill in the West Branch and tribs N of UNV.
The valley fog should continue to expand. Thus far, not bad or
widespread enough for a fog advy. Lower clouds moving up from
the S are not solid as of yet. 00Z NAM continues to be the most
aggressive model at cloud coverage/spread northward. Thus far,
it`s too aggressive. We`ll keep with the going fcst of overcast
not quite getting up to I-80 by sunrise.
SEG the cold spot at 51F at 02Z. Low temps will range from
mid/upper 40s in the northern tier to mid 50s along the MD
border (+5-10F above the historical average for early October).
When clouds arrive/develop in the S, they might help temps go up
a couple degs, and almost certainly level them off.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH SUNDAY/...
Valley fog and low clouds to start the day on Friday. Model
guidance indicates a shortwave trough rotating through the lower
Great Lakes tomorrow afternoon/evening coinciding with a surge
of low level moisture in advance of a weak sfc cold front. These
features will combine to drive low POPs over the northern and
eastern portions of the CWA through Friday night.
Warm advection preceding the cold front should push temps into
the low to mid 70s Friday afternoon with the largest anomalies
over the Allegheny Plateau, where the most sunshine is expected.
High pressure and an associated low-pwat airmass is progged to
build southeast into PA Saturday, providing the region with
mostly sunny skies. Ensemble mean 850mb temps in the 7-9C range
support highs ranging from the mid 60s over the N Mtns, to the
mid 70s in the Lower Susq Valley. Have undercut NBM dewpoints
Sat afternoon based on model soundings, which show very dry air
above a weak inversion.
Fair and seasonable weather appears likely into the second half
of this weekend, as surface high pressure builds across the
state. We`ll continue to slightly undercut NBM min temps
Saturday night, when conditions favor efficient radiational
cooling directly under the surface high. This will also be
favorable for morning fog across typical fog prone areas across
the Commonwealth through the weekend.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Increasing clouds ahead of the next chance of showers are
expected Sunday night as a cold front approaches central
Pennsylvania. This forecast continues to outline the best
chances for rainfall in the overnight period into Monday morning
across the northern tier and the Laurel Highlands. Rainfall is
expected to continue with a east/northeasterly progression
throughout the Monday morning hours. Instability continues to
look fairly limited to the earliest hours Sunday night across
the western highlands along with the Lower Susquehanna Valley,
so have retained SChc of thunderstorms in this period. Storm
chances decrease closer to daybreak on Monday, so have limited
precipitation mentions to just showers this forecast cycle.
Enhanced westerly flow in the wake of the cold front will allow
for lingering showers across mainly NW PA throughout the day on
Monday. Guidance does outline high pressure beginning to build
into the area late Monday and into the mid-week allowing for
drier conditions to prevail for the bulk of central PA although
have retained low-end SChc PoPs across NW PA on Wednesday with
enhanced westerly flow continuing throughout the period.
High pressure influencing the area will allow for clear/mostly
clear skies which does promote undercutting NBM MinTs Tuesday
and Wednesday nights. The combination of clear skies, light
winds,and cooler temperatures start to bring the first concerns
of frost into the forecast across N PA. Have introduced frost
mentions on Tuesday night given a slightly more favorable set-
up for frost formation while limiting mentions on Wednesday
night due to more uncertainty, but given similar environmental
set-up, subsequent forecast packages may need to introduce
frost mentions for this period.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Mainly clear skies with calm winds and prevailing VFR conditions
are present over the airspace for the start of the 00Z TAF
package. The area had the chance to dry out some today with
plenty of sunshine throughout the day, so fog will not be as
quick to form as last night.
After 06Z Friday, fog concerns begin entering the forecast
area again, with the highest probabilities in HREF guidance
lighting up at AOO (09-13Z Friday) and UNV (10-13Z Friday) with
lower- level cloud decks being the main concern. There is some
spread in model guidance with GLAMP being less keen on any
restrictions throughout the period; however, given a combination
of previous GLAMP model cycles, RAP model soundings, and HREF
probs, have outlined a period of MVFR/IFR conditions throughout
this timeframe. There is moderate (40-50%) confidence in
restrictions at AOO/UNV with lower confidence on low-level
moisture manifesting further east at IPT/MDT/LNS overnight.
Any valley fog formation begins to mix out ~14Z Friday with VFR
conditions expected outside of the Lower Susquehanna Valley
through 18Z Friday with moderate (~60%) confidence. Guidance
does suggest a lower-level (~2-4kft) cloud deck making way into
LNS/MDT for a period of MVFR ceilings early in the day before
scattering back towards VFR in the 18-20Z Friday timeframe.
Outlook...
Sat-Sun PM...Patchy AM Valley Fog; otherwise, VFR prevails.
Sun PM-Mon...SHRA moves in west-to-east, some TSRA possible.
Tue-Wed...VFR, no sig wx.
&&
.CLIMATE...
Total precipitation for the month of September was 1.11 inches
at Williamsport (-3.65" below average) which ranks as the 11th
driest on record.
The average temperature for the month of September was 63.1
degrees at Bradford (+4.2F above average) which ranks as the
warmest September on record.
Harrisburg (MDT) consecutive days streak of measurable rain
ends at 9 with only a trace recorded yesterday 10/2. This ties
the record for longest such stretch set from April 7-15, 1893
and matched May 15-23, 1893 and July 28-August 5, 1971.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Steinbugl
NEAR TERM...Dangelo/Steinbugl
SHORT TERM...Fitzgerald/Steinbugl
LONG TERM...NPB/Bowen
AVIATION...NPB/Bowen
CLIMATE...Steinbugl/Banghoff
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
629 PM CDT Thu Oct 3 2024
.KEY MESSAGES...
- Warm And Mostly Dry
- Very Light Rain Possible Northeast Missouri Early Friday
- Windy Saturday, Elevated Fire Weather Concerns
&&
.DISCUSSION...
Issued at 355 PM CDT Thu Oct 3 2024
Strongest PV anomaly is currently centered over Hudson Bay with
general troughing across the far north-central CONUS. This is
placing the strongest jet streak from the eastern Dakotas into the
western Great Lakes Region. There is an AVA regime that extends from
the Northern Rockies toward the Sand Hills Region of Nebraska where
subsidence has been developing a surface anticyclone. A thermal
boundary that is tied to the system in Canada has a pretty far reach
and was being pushed by the anticyclone toward the area, but a weak-
short wave promoting just enough dCVA over the Southern Plains has
generated cyclogenesis across the Central Plains, with surface
pressure trough extending into the middle Mississippi River Valley.
This has turned low-level flow southerly today, providing WAA,
allowing temperatures to reach the upper 80s and lower 90s across
much of the area. This has also stalled the thermal boundary, and is
currently stationary from north-central Kansas to east-central Iowa.
With the dry airmass that has been in place, there has not been any
precipitation production through this afternoon. A few cumulus
clouds did try developing in an area of weak convergence, but dry
air did not allow any clouds to live for any extended periods of
time. Clear skies did allow for deeper boundary layer mixing today,
and provided wind gusts to near 20 MPH at times. These should
diminish with sunset. Heading into the overnight hours, surface
pressure falls will extend toward the northeast, while H5 short-wave
trough axis moves across northern Missouri. This trough axis is no
longer in phase with the stronger PV anomaly troughing well to the
north. In our far northeast, there is an increasing signal for
increased kinematic support, especially heading into the early
morning hours of Friday. GFS and RAP solutions have displayed
increasing Q-vector convergence, with strongest lift being focused
from southeast Iowa into west-central Illinois, but does clip our
far northeastern CWA. The CAMs has been showing decent development
and have not backed off on trends over the past 12 hours of model
runs. Further, coarser scale ensemble suites have also showed
increasing probabilities for measurable precipitation along this
corridor of increased convergence (some suites showing over 80
percent for at least 0.01 inches of QPF). Even the 12z HREF mean has
shown a few hundredths of an inch of QPF in our far northeast.
Therefore, will place slight chance and chance POPs for our
northeastern counties starting late tonight through early Friday.
Surface dewpoints at the moment are quite low, but an axis of
moisture may be advected through the evening closer to the
Mississippi River Valley that increases the moisture content. Model
soundings do show drier air still aloft, which may eat into any
developing showers, especially for our counties. The greater axis of
moisture will be northeast of our area. HREF mean MUCAPE values are
around 750 J/kg, perhaps allowing a brief thunderstorm to develop.
But the lack of wind shear will prevent organized activity (if
anything develops at all). For the most part, the mode may just be
general showers. Elsewhere in the forecast area, a mostly clear and
dry conditions Thursday evening and Friday are forecast.
Friday, the thermal boundary is progged to remain stalled somewhere
in our northern CWA. The weaker H5 short-wave axis moves east of our
area, and the previously mentioned surface cyclone/surface pressure
falls becomes less defined as area of weak subsidence attempts to
wash it out. The anticyclone over the Central Plains may slide
further toward the southeast if enough subsidence from the backside
of the stronger PV anomaly is also able to slide southeastward. This
may slide the thermal boundary further southeast as well, which will
keep our northern counties cooler, mainly in the upper 70s, while
areas south of Interstate 70 reach the mid to upper 80s. We may see
a few cumulus clouds develop along the area of convergence, but the
lack of moisture advection should help keep plenty of sunshine
around the area. As the pressure gradient weakens, winds will not be
overly strong on Friday afternoon. Without the stronger WAA,
temperatures Friday are not forecast to be as warm as they were on
Thursday. Saturday, another stronger trough moving across Canada is
expected to dig into the Northern Plains and provide mid-level
height falls through much of the Central CONUS, as well as breaking
down ridging over the southwest CONUS. While stronger jet dynamics
remain further north, it does appear we will see a period of
stronger pressure falls, and surface trough extending into our
forecast area. This pushes a strong cold front across the Northern
Plains, heading toward the southeast. Ahead of this, low-level flow
turns south-southwesterly and provides another shot of WAA into the
forecast area. This is expected to boost temperatures back into the
upper 80s and lower 90s across the forecast area, and most ensemble
suites inner-quartile ranges are clustered in this range. In
addition, especially with current drought conditions and dry soils,
clear skies are expected to promote fairly deep boundary layer
mixing, which will help augment temperatures, and also increase the
wind gusts. Current model soundings are suggesting the top of the
mixed-layer to hit near 38 kts. For Saturday afternoon, have
increased the wind forecast closer to the NBM 90th percentile, to
capture wind gusts between 25-30 MPH most of the afternoon, with a
few pockets of 30-35 MPH. At the current moment, RH values are
expected to be around 30 percent, though if mixing is even more
robust then currently expected, could drop lower during peak heating
hours. As of now, this is not quite at thresholds needed for
headlines. With that being said, elevated fire weather concerns will
be present on Saturday, mainly being aggravated by extended drought
conditions and dry soils across the region. Over the next 24 hours,
forecast trends will continue to be monitored to see if thresholds
near closer to headline criteria. Despite the strong convergence and
slightly increased flow, the moisture is not expected to be there
for precipitation on Saturday. Ensemble probabilities are less than
10 percent for measurable rain, therefore, will call for a dry
forecast through the remainder of the weekend.
Next week, temperatures should be slightly cooler with the passage
of the weekend cold front and system. General ridging is expected,
and very little in the way of moisture return, thus forecast will
remain dry. For the most part, ensemble probabilities for
measurable rainfall are generally less than 10 percent for much of
the latter part of the 7 day forecast. The GEFS and even
deterministic GFS has painted a few stripes of light QPF through
parts of eastern Kansas Tuesday into Wednesday, but no signal
reaches our forecast area. Temperatures will generally be in the mid
70s, as this is where most of the inner-quartile range amongst
ensemble suites is clustered for afternoon high temperatures.
Morning lows will generally be in the 50s, a few locations northward
may see mid to upper 40s. There is not a great signal for any kind
of drought relief through next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 628 PM CDT Thu Oct 3 2024
VFR conditions are expected to remain for the duration of the TAF
period. Winds will eventually shift to the north and remain fairly
weak with an occasional gust to 15 mph late tomorrow
morning/afternoon.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.
&&
$$
DISCUSSION...Krull
AVIATION...Collier
Area Forecast Discussion
National Weather Service Melbourne FL
952 PM EDT Thu Oct 3 2024
...New UPDATE...
.UPDATE...
Issued at 952 PM EDT Thu Oct 3 2024
Isolated onshore moving showers have developed along the southern
Brevard and Treasure Coasts this evening. Here, model guidance
continues to suggest increasing coverage of showers and occasional
storms overnight. In particular, the HRRR shows run to run
consistency in developing a heavier band of precipitation along
the coast from Melbourne southward which will be capable of
producing rainfall accumulations of 1 to 3 inches. Highly
localized amounts up to 6 inches remain possible. Northern
counties remain dry overnight. Low temperatures will mostly range
the mid 70s, falling into the low 70s across rural areas.
&&
.PREVIOUS DISCUSSION...
Issued at 331 PM EDT Thu Oct 3 2024
KEY MESSAGES...
- Locally heavy rainfall is forecast tonight along the Treasure
coast with add`l potential for heavy rain late weekend into
next week over east central Florida.
- Increased risk of rip currents and rough surf this weekend into
next week.
Tonight...A very moist airmass south of the Cape will combine with
increased easterly flow and coastal convergence to produce a heavy
rain threat focused on south Brevard, Indian River, Saint Lucie
and Martin counties. HRRR ensemble model guidance is showing mean
rainfall amounts of 1-3" along the coast with highly localized
amounts of 6"+ possible. Be especially cautious during nighttime
flooding.
Friday-Saturday (previous)...Reduced moisture across the northern
extent of east central Florida during this period will work to
temporarily decrease rain chances for the first half of the
weekend. East- northeasterly flow will persist, at times becoming
gusty closer to the coast, as high pressure tries to press south
along the northeast Florida coast. Temperatures slip a bit, only
reaching the upper 80s each afternoon and falling into the 70s
overnight. Where 2" PW can outlast the drier air, namely along a
line from Leesburg to Lake O and Stuart, PoPs max out around 30-40
percent each afternoon.
Sunday-Wednesday (modified)...A shift in the pattern begins
Sunday as high pressure loses its influence on the southeast U.S.
and a warm front becomes stationary across south-central FL. An
area of possible tropical development will continue to be
monitored in the Gulf of Mexico. NHC/WPC are depicting an
elongated trough with possible low pressure over the SW Gulf
moving E/NE then turning SE Tue-Wed.
What models primarily agree on is a quick return of deep moisture
across central and south FL from Sunday into next week. This will
result in more cloud cover, higher coverage of rain, and a few
lightning storms. Instability does not appear as impressive
through the extended period, owing to the tradeoff between more
clouds/less diurnal heating. However, the threat of heavy rain and
instances of localized flooding are expected to increase next
week. In fact, the Weather Prediction Center has already outlined
central and south FL in a Marginal Risk for excessive rainfall on
Monday and this may be extended to Tue as well. Key features to
monitor, which will determine areas with the highest QPF, include
where the deepest moisture advects across the FL peninsula and the
location of the frontal boundary. The GFS shows several convective
clusters moving across the peninsula with very heavy rain but
mostly north of the frontal boundary. It is along the front itself
that episodes of heavy rainfall would be most likely early to mid
week.
Finally, long period swells from distant Hurricane Kirk will make
the surf zone increasingly hazardous this weekend into next week.
producing a High risk of rip currents, rough surf and minor beach
erosion. The swells are forecast to peak at 4 ft/15 sec periods
Sun night and Monday with potential for runup to the dune lines or
seawalls (especially around high tide times). While a High Surf
Advisory is not anticipated, a Coastal Flood Advisory is possible
given the energy these long period swells will impart onto the
beaches.
&&
.AVIATION...
(00Z TAFs)
Issued at 743 PM EDT Thu Oct 3 2024
Dry at all terminals to start the 00Z TAF. Overnight showers and
occasional storms are then forecast to develop along the coast
from TIX southward. Have included a mention of VCSH/VCTS for now
due to low confidence in overall coverage, but will continue to
monitor trends for potential TSRA TEMPOs at the Treasure Coast
terminals where coverage could be greatest late tonight. VCSH/VCTS
at all terminals tomorrow afternoon for routine diurnal showers
and storms. Light east winds overnight increase to 7-10 kts
tomorrow.
&&
.MARINE...
Issued at 331 PM EDT Thu Oct 3 2024
Convection will increase this eve and overnight over the Atlc
waters mainly south of the Cape and push onshore over the
intracoastal waters. Long period swells from distant Hurricane
Kirk will reach the local waters this weekend, especially from
Sunday into early next week. High pressure on Friday-Saturday
breaks down later in the weekend as a surface front lifts north
across the waters into early next week. Onshore flow around 12-15
kt Fri/Sat increases to 15 kt (with gusts up to 20 kt) Sun/Mon.
Seas build gradually, 4-5 ft Fri (6 ft offshore), 4-6 ft Sat/Sun
(7 ft offshore), eventually reaching 5-7 ft Mon (8 ft offshore).
Scattered showers and lightning storms stay in the forecast,
increasing in coverage late weekend into next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 75 88 75 86 / 10 30 10 40
MCO 75 89 74 88 / 10 30 10 30
MLB 77 88 76 87 / 20 30 10 20
VRB 77 88 76 88 / 40 30 10 20
LEE 75 90 74 88 / 10 30 10 30
SFB 75 89 74 88 / 10 30 10 40
ORL 76 89 76 88 / 10 30 10 30
FPR 76 88 76 87 / 40 40 10 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
UPDATE...Law
AVIATION...Law
Area Forecast Discussion
National Weather Service Phoenix AZ
405 PM MST Thu Oct 3 2024
.UPDATE...
Updated Aviation
&&
.SYNOPSIS...
Temperatures upwards of around 15 degrees above normal and high
temperatures near or breaking daily records will be common through
early next week, under mostly sunny skies. An Excessive Heat Warning
is in effect through Monday evening for portions of the region.
Please protect yourself from the heat.
&&
.DISCUSSION...
The heat wave continues as unseasonably hot, record-breaking
temperatures persist across the Southwest. So far this afternoon,
Phoenix has reached 107 degrees, breaking the previous record high
of 105 degrees last set in 2020. This is now the 10th consecutive
day where a daily record high in Phoenix has been either tied or
broken. Record highs will continue remain in jeopardy through at
least the first half of next week.
This unseasonable heat is all thanks to a strong ridge of high
pressure that remains parked over the Desert Southwest. Latest RAP
analysis showed the upper level ridge centered near southern
California this afternoon with 500 mb heights over the region around
588 dm. This ridge of high pressure will continue to promote dry
conditions and well above normal temperatures through the rest of
this week and into early next week. The ridge strengthens heading
into this weekend as global ensembles show 500 mb heights climbing
to around 592-593 dm. Given this, it not`s out of the question that
we could squeeze another 110 degree temperature in this year for
Phoenix. High temperatures reaching 110 this late in the year is
pretty unfathomable at this point given the lowering sun angle,
length of day, and considering the previous latest 110+ on record
prior to this year for Phoenix was Sep 19, 2 weeks ago from today.
The average (1991-2020) last occurrence of 110 degrees in Phoenix is
August 26th, so we are now well beyond the average. At this point,
the last 110 degree day this year is closer to the average last
occurrence of 100 degrees, which is October 5th. NBM probabilities
for breaking record highs in Phoenix will remain in excess of 90%
through Monday while widespread Major and areas of Extreme HeatRisk
persist. Thus, the Excessive Heat Warning has now been extended
through Monday.
Going into the middle part of next week, a weak trough is expected
to setup near the southern California coast. This will help drop
heights over the region some and thus lead to a slight downtrend in
temperatures for the mid to latter part of next week. Despite this
downtrend, temperatures will continue to remain above normal as the
NBM shows good agreement and very little spread that highs will
continue to remain in the triple digits. Guidance also show an
increase in moisture going into the middle part of next week. This
could be enough to promote some shower activity across the Arizona
high terrain while the lower deserts are favored to remain dry.
There are indications that by the end of next week we could be
seeing deeper troughing across the eastern Pacific that could help
further push temperatures down, but we will have to wait and see how
this trends given that it`s more than a week out at this point.
&&
.AVIATION...Updated at 2305Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major weather issues will exist through Friday evening under
mostly clear skies. Confidence is very good that wind patterns will
follow a pattern nearly identical to the past 24 hours with west
winds shift to an easterly component late evening, then back to
west early Friday afternoon.
Southeast California/Southwest Arizona including KIPL and KBLH:
No weather issues will exist through Friday evening under clear
skies. Wind patterns will be nearly identical to the past 24 hours
with extended periods of nearly calm conditions common.
&&
.FIRE WEATHER...
Dry and abnormally hot conditions will persist through early next
week, with lower desert highs ranging between 103-111 each
afternoon. MinRH values will range between 5-15% each afternoon,
while MaxRH readings are expected to be between 20-35%, with locally
higher values in Yuma and Imperial Counties. There will be a very
slight increase in moisture by the middle of next week that may keep
MinRH values from falling into the single digits, but most areas
will still see 10-15% readings in the afternoon. Winds will follow
familiar diurnal trends, with occasional afternoon gusts near 15-25
mph.
&&
.CLIMATE...
Record highs through the next week:
Date Phoenix Yuma El Centro
---- ------- ---- ---------
Oct 3 105 in 2020 108 in 1952 108 in 1952
Oct 4 105 in 2020 109 in 1952 106 in 1952
Oct 5 105 in 2020 108 in 1917 106 in 2020
Oct 6 105 in 1917 108 in 1980 106 in 1964
Oct 7 104 in 1991 108 in 1987 105 in 1991
Oct 8 104 in 1987 107 in 1996 106 in 1996
Oct 9 103 in 1996 106 in 1996 104 in 1996
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Monday for AZZ530>544-546-
548>551-553>555-559.
CA...Excessive Heat Warning until 8 PM PDT Monday for CAZ562-566-567-
569-570.
&&
$$
DISCUSSION...Smith
AVIATION...18
FIRE WEATHER...Benedict/RW
CLIMATE...18
Area Forecast Discussion
National Weather Service Raleigh NC
910 PM EDT Thu Oct 3 2024
.SYNOPSIS...
Weak high pressure will extend into the region from the northeast
through Friday. A cold front will move east across the area late
Saturday. Weak high pressure will arrive on Sunday. A much stronger
cold front will move across the eastern U.S. on Monday. A much
cooler and drier air mass will spread across the area through the
middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 910 PM Thursday...
Minimal changes needed with the evening update. Tweaked hourly
grids, but any chance of a passing shower should be over. Previous
discussion follows.
As of 210 PM Thursday...
1016 mb high pressure over the central Appalachians extends into NC
between a trough pinned to the mountains and a low pressure well off
the east coast. An upper level ridge blankets the Southeast,
resulting in a strong subsidence inversion at 750mb (per 12Z GSO
raob). There is ample moisture below the inversion, with slowly
eroding stratus over the western Piedmont even as of 18z. There is
no change in the airmass tonight, so fog and stratus should once
again develop, though the SREF and HRRR tend to favor the northern
Piedmont/coastal plain.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 150 PM Thursday...
The mid and upper level ridge across FL and the Bahamas on Friday
morning will shift east and fold over on Friday night into Saturday.
A progressive northern stream trough will move across the Great
Lakes on Friday and into New England on Friday night. Meanwhile a
mid-level weakness across the Deep South on Friday morning will
shift east with a couple of vort maxes moving across the Carolinas
late Friday afternoon/evening and Friday night before elongating and
shifting to the coast by daybreak Saturday. At the surface, high
pressure centered off the New England coast will extend southwest
into the mid-Atlantic with a very light low and mid level flow. A
weak surface disturbance off the coast near Cape Fear Friday morning
will drift west into southern NC during the morning. Deep layer
moisture on Friday morning is a little above normal with PW values
of around 1.25 inches with moisture increasing a bit to around 1.5
inches or 140% of normal by Friday night.
Friday morning will begin with a fair amount of early morning fog
and a little bit of stratus. As the fog and stratus lifts during the
mid morning hours, high and then mid clouds will increase from the
west and southwest, resulting in a limited amount of sunshine.
Mostly cloudy skies are expected across central NC by mid to late
afternoon and continue into the evening hours. As the mid and upper
level disturbances shift east, a few sprinkles or showers may move
across the area. Guidance PoPs are very low, generally less than 5
or 10% but a handful of CAMS suggest there is a chance of a shower
across the western Piedmont from 19 to 23Z where there is a hint of
instability and perhaps another area of showers across the Sandhills
and southern Coastal Plain from 20 to 01Z. Rain chances are very
limited and the vast majority of central NC will not experience any
precipitation. Afterwards, the high and mid clouds will shift east
by late Friday night resulting in partly to mostly clear skies by
daybreak Saturday.
Highs on Saturday should range in the upper 70s to lower 80s. Highs
could over perform if clouds are a little thinner and more sunshine
is experienced. Lows on Friday night should range between 60 and 65
with perhaps a few upper 50s near the VA border. -Blaes
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 150 PM Wednesday...
Mid and upper level trough will shift off the New England Saturday.
Meanwhile a plume of upper level moisture will be shifting south
through the morning and afternoon, resulting in clearing skies from
north to south through the afternoon. After that, ridging across the
eastern US takes over late Saturday and Sunday before another wave
of upper level moisture moves across the region Monday and Tuesday
associated with a strong upper level low over eastern Canada. Upper
levels will remain dry Wednesday and Thursday with NW flow.
At the surface, a weak cold front will move through the area
Saturday and early Sunday. Ensemble guidance is showing the front to
be dry as it moves across the region, with most of the moisture
staying to the south and east. After that, another high pressure
building across the Central Plains will shift across the MS valley
bringing a stronger dry cold front across the region Monday/Monday
night. Again this is expected to be dry as the front moves across NC
bringing a taste of fall to the region Tuesday Wednesday and
Thursday.
Temperatures will be above average Saturday through Monday with
highs generally in the upper 70s to low 80s. After the front moves
through sometime Monday, expect refreshing fall like temps with
highs in the low to mid 70s Tuesday and upper 60s to low 70s
Wed/Thurs. Lows will begin to drop Monday night with low in the low
50s to low 60s. Radiational cool will be strong each night after
with lows in the upper 40s to low 50s.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 750 PM Thursday...
VFR conditions will likely hold through this evening, but there is a
chance for sct-bkn MVFR clouds and patchy MVFR vsbys in fog early
Fri morning, mainly 09z-13z. Confidence is not high, however, as the
trend of model guidance has been for lower chances of low cigs and
vsbys, and there may be enough stratocu at 3-5kft across the
northern terminals to hinder low cloud development. But given that
areas of sub-VFR conditions occurred last night under similar
conditions, the risk is not zero. The highest chances for sub-VFR
cigs/vsbys during that 09z-13z window will be at INT/GSO. VFR
conditions should return by 14z, although with very light winds
across the area through this TAF period, INT/GSO may see MVFR cigs
persist until 17z. Rain chances will remain very low.
Looking beyond 00z Sat, VFR conditions should hold over the area
through early next week, with low rain chances. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Blaes
NEAR TERM...Green/BLS
SHORT TERM...Blaes
LONG TERM...CA
AVIATION...Hartfield
Area Forecast Discussion
National Weather Service Topeka KS
624 PM CDT Thu Oct 3 2024
.KEY MESSAGES...
-Summer-like heat is occurring today, and expected again on Saturday.
-Fire weather concerns are increasing Saturday with a trend toward
lower RH and higher winds.
-Deep layer moisture looks to remain lacking, keeping the long-
term forecast dry.
&&
.DISCUSSION...
Issued at 213 PM CDT Thu Oct 3 2024
Temperatures are off to the races today with some locations already
exceeding the 90 degree mark early this afternoon. At 19Z, surface
obs show low pressure over central KS and an inverted trough
extending into far southeast Nebraska and central Iowa. Conditions
north of the trough axis are in the low and mid 70s with breezy
northeast winds. South of the boundary, winds are southwest and
temperatures are unseasonably warm. Water vapor and mid-level RAP
analysis show a low-amplitude trough axis moving toward the Great
Lakes. As that trough continues eastward, the surface low will slide
south, and the cooler/drier air mass north of the area will advect
southward tonight. Temperatures tomorrow will be cooler than today
but still above climatological averages (the current average high in
Topeka is 75 degrees).
A progressive northern stream mid-level pattern will bring a deeper
trough axis across the Pacific Northwest and into south-central
Canada tomorrow and Saturday. Warm southerly low level flow
returning ahead of that next system combined with efficient boundary
layer mixing will allow for another very warm day Saturday. Have
trended slightly lower with dew points, given mixing, and higher
with winds. These conditions will set the stage for higher fire
weather potential -- see the fire discussion below for more
information. A cold front associated with Saturday`s system will
move through the CWA that evening. A surface ridge builds in behind
the boundary, helping to cool temperatures back toward the upper 70s
and low 80s for highs Sunday and Monday.
Looking longer term, there has not been much change to the forecast.
Temps warm slightly through midweek. The overall pattern still looks
to lack a system with efficient moisture return to produce
precipitation. Thus, the next seven days currently remain dry.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 624 PM CDT Thu Oct 3 2024
Timing of a southward moving frontal boundary puts it through
MHK around 02Z and by 04Z at TOP and FOE. Winds shift from the
southwest to the north. Winds then veer to the northeast around
10kts after 12Z Friday. VFR conditions are forecast to continue.
&&
.FIRE WEATHER...
Issued at 214 PM CDT Wed Oct 3 2024
Fire weather conditions are becoming more of a concern on
Saturday. With dry weather continuing, hot and windy conditions
could create the potential for difficult to control fire
behavior, should any fires get going. Minimum afternoon relative
humidity will be range from around 20 percent in northern and
north-central KS, to around 30 percent in far eastern KS.
Sustained south-southwest winds around 20 mph with gusts near 30
mph are expected through the afternoon. Winds will then
abruptly shift to the north behind a cold front during the
evening hours. To be cautious, burning should be avoided.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Teefey
AVIATION...53
FIRE WEATHER...Teefey