Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/03/25
Area Forecast Discussion
National Weather Service Charleston SC
1046 PM EDT Fri May 2 2025
.SYNOPSIS...
High pressure will prevail through tonight. A cold front will
affect the area this weekend, then potentially linger nearby
into early next week before high pressure builds in again from
the west.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Tonight: High pressure centered across the Atlantic and extending to
the Southeast Coast will gradually give way late while a large
trough digs south toward the ArkLaTex region. The trough will nudge
a cold front east with time, reaching the Southeast United States
after daybreak Saturday. Expect a slight uptick in southerly flow
well ahead of this feature, allowing for a slightly more mild night
under high clouds. Most areas are expected to remain dry, but there
is one exception well inland. Convection continues to occur along a
boundary across Central Georgia and the South Carolina Upstate.
While this activity could cool pool southeastward with time, drier
air depicted on soundings and weak instability locally will likely
limit activity from reaching far western zones. However, should
activity reach the area it would be in a weaker state, mainly
showers, with an arrival time around 2-3 AM. At this time, a precip-
free forecast remains, but the approaching boundary will need to be
monitored for he potential of including showers for a brief period
across inland zones overnight. In general, low temps should range in
the low-mid 60s inland to upper 60s/around 70 near the coast. A few
spots could dip into the upper 50s across the Francis Marion Forest
late night.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Saturday a closed low in the mid-levels will be positioned over the
Middle Mississippi Valley will set up an omega block pattern over
the CONUS, with ridging building into the Southern Plains and
another mid-level closed low over the west coast. This omega block
pattern will dominate the upper levels into early next week. At the
surface a cold front will slowly push into the local forecast area
Saturday evening and into Sunday before stalling in the vicinity
of the coastline.
Saturday will see the region`s first widespread shot at rain in a
while, however, despite forecast PWAT values of upwards of 1.5",
both the HRRR and the HREF are not overly impressive with the
coverage of showers and thunderstorms. The forecast features PoPs
generally 60-80% across the region Saturday night into Sunday at
this juncture, but these values will likely need to be adjusted as
additional short term guidance comes in. There is a low end
potential for a strong to severe thunderstorm, with shear values
around 30 to 40 knots. The limiting factor for severe storms will be
the lack of instability, with CAPE values only around 1000 J/kg. The
greatest chance for a strong to severe thunderstorm will be across
inland SC/inland GA where there are better instability values.
Showers and thunderstorms could linger into Sunday, with PoPs around
60% Sunday afternoon. While there is a chance for a strong to severe
thunderstorm again on Sunday, the chance is lower than on Saturday
due to even lower instability values.
High temperatures on Saturday will reach into the mid to upper 80s,
with around 80 at the direct coastline. Conditions will remain mild
overnight Saturday into Sunday due to cloud cover and possible
precipitation, only dropping into the 60s with around 70 at the
beaches. Slightly cooler conditions are expected on Sunday as the
cold front begins to push through, with upper 70s to low 80s
forecast. Overnight Sunday into Monday a cooler airmass will be
ushered in by the cold front, with lows in the 50s to mid 60s along
the beaches.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The omega block pattern begins to break down mid week as the closed
low over the Middle Mississippi Valley pushes eastward and exits the
CONUS off the New England coastline. The forecast through mid-week
will remain dry, with slight chance to chance PoPs returning through
the end of the week, as another cold front approaches the region.
Temperatures will return to near normal through the week.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected at CHS/JZI/SAV terminals through 00Z
Saturday. However, gusty south to southeast winds are expected to
develop at all terminals Friday afternoon, topping out near the 20-
25 kt range. Cloud cover and precip chances increase late in the TAF
period, but probabilities remain too low to include in the latest
TAF issuance.
Extended Aviation Outlook: Showers and thunderstorms are expected to
impact CHS/JZI/SAV Saturday afternoon into Monday morning as an
approaching cold front passes through the region.
&&
.MARINE...
Tonight: High pressure centered across the Atlantic will extend to
the Southeast Coast while a trough approaches the region late night.
A slight tightening of the gradient is possible, holding a
southeast/south wind across local waters in the 10-15 kt range
through much of the night. Seas will range between 1-3 ft, but
should gradually build to the 2-4 ft prior to daybreak (largest
across outer Georgia waters).
Saturday through Wednesday: Southerly winds could surge slightly
Saturday afternoon into Sunday as a cold front pushes through,
however conditions are expected to remain below Small Craft Advisory
criteria. East-southeasterly swell begins to mix in on Saturday and
into Sunday, expect seas to be from 3 to 5 ft over the weekend, and
then decrease to 2 to 3 ft for the rest of the period.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...DPB
SHORT TERM...CPM
LONG TERM...CPM
AVIATION...CPM/DPB
MARINE...CPM/DPB
Area Forecast Discussion
National Weather Service Gray ME
1041 PM EDT Fri May 2 2025
.SYNOPSIS...
Showers and some thunderstorms are possible this afternoon
along a cold front. This front slows, allowing for a renewed
chance of showers and thunderstorms Saturday. Some of these
thunderstorms may be strong to severe, capable of producing
gusty winds and small hail. The front eventually stalls over
the area continuing unsettled conditions into early next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1040 PM Update...Latest radar shows an area of showers with
embedded thunder tracking east across Rockingham County into
York County and will likely move offshore over the next hour or
two. There is another area of showers over the Hudson Valley
that may track across southern NH late tonight. Areas that have
received recent rainfall this evening have had fog develop and
have mainly adjusted fog coverage and PoPs with this update.
855 PM Update...Despite growing CIN over the area a couple of
thunderstorms have been able to maintain themselves over central
and SW New Hampshire as there is a few hundred J/kg of elevated
instability. Have increased PoPs to cover these thunderstorms
and added thunder to the forecast through the next couple of
hours.
Previously...
Breaks in the clouds this afternoon will allow for a
destabilization of the environment over New Hampshire and the
interior. A few thunderstorms are likely to develop this
evening across New Hampshire by 6pm or so. Storms will continue
through the rest of the evening, moving out of the area tonight.
Light southeasterly flow over the waters will help advect low
stratus and fog into Maine this evening, continuing through
tomorrow morning.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Tomorrow morning, skies lift up and any leftover fog starts to
mix out. Late morning clearing should allow for temperatures to
warm sharply through the day, especially away from the coast.
The clearer skies should allow for destabilization. Some forcing
moving in early tomorrow afternoon should help build some some
thunderstorms across New Hampshire. Convection could become
more organized across the south as CAPE, updraft helicity and
mid-level lapse rates become more favorable for strong to
severe thunderstorm development. The Storm Prediction Center
(SPC) has also issued a `Marginal Risk` for Southern New
Hampshire and York County ME, indicating a 5% chance for hail
and/or damaging winds over the aforementioned area. Storms
should move out of the area by sunset.
After the aforementioned convection crosses the region, a low
pressure system to the west may continue to bring more showers
into New England overnight, with showers potentially continuing
through the day on Sunday.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
1040 PM Update...No major changes with the latest NBM guidance.
There will be chances for showers most days next week as a cut-
off low slowly tracks across the Ohio Valley into the
Northeast. The highest chances for widespread soaking rainfall
will occur late Tuesday into Wednesday as the low makes its
closest pass to New England.
Previously...
Pattern Overview: A 500 mb low will be slowly meandering
eastward from the Ohio Valley through our area, departing mid-
week. This along with a series of fronts, keeps clouds and
showers in the forecast. There is some uncertainty toward the
end of the week as the Euro suite shows another 500 mb low
swinging in right behind the departing one, but the GFS shows
nicer weather returning.
Impacts and Key Messages:
* No significant weather impacts expected.
* The area will see beneficial rain as low pressure brings
rounds of showers through the weekend and at least the first
part next week.
Details: Sunday: A wave of low pressure rides along a stalled
frontal boundary draped across the area Sunday. The latest hi-
res model suite is still uncertain on just how far south the
boundary makes it before stalling, with the NAM Nest continuing
to be the outlier that isolates showers to the coast. The tail
end of the HRRR and the RRFS are in the camp of the boundary not
making it much past the mountains. Will go with a consensus
approach, keeping at least a chance of showers across the area,
with more likely probablilites south of the mountains. Global
models remain in good agreement that high pressure building into
the area overnight Sunday pushes the front along, but it may
not clear the coast until early Monday. These showers look light
with some embedded heavier showers, but generally areas could
see another 0.25-0.50 inches with Sundays shower activity.
Monday and Tuesday: As mentioned above, light showers may
linger across southern New Hampshire into Monday morning as high
pressure continues to push a frontal boundary out of the area.
Ultimately, this brief nose of high pressure looks to keep
Monday mostly dry, but our proximity to the meandering 500 mb
low likely keeps skies mostly cloudy across much of the area.
High temperatures may not make it out of the 50s with the
increased cloud cover, and as such low temperatures only bottom
out in the 40s. As high pressure slides eastward overnight
Monday and the first part of Tuesday, this will allow the
vertically stacked low pressure to begin moving toward our area.
There are some subtle differences in timing, but the trend has
seemed to hold steady with the more widespread showers holding
off till later on Tuesday. Skies remain cloudy through the day
so high and low temperatures remain very similar to Monday.
Wednesday-Friday: Low pressure moves overhead Wednesday, so
widespread showers look to continue into at least the first part
of the morning. How quickly showers exit is a point of
uncertainty in the model suites, but that is unsurprising at
this time range. Thursday and Friday are also a big question
mark as the Euro brings another upper level low into the area
right behind the one departing, and the GFS builds high pressure
in. For now the NBM probabilities seem reasonable with a chance
of showers through the day Thursday, then decreasing heading
into Friday.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Lowered restrictions are expected this afternoon as
showers and low stratus move through the area. These restrictions
will continue overnight as areas of fog build across New Hampshire
and Maine, bringing periods of IFR overnight. Some improvement is
possible across southern NH tomorrow morning as fog mixes out,
but restrictions lower tomorrow afternoon as storms develop and
move across the New Hampshire and Maine. Showery weather may
still keep restrictions lower through Sunday morning.
Long Term...Sunday will likely feature a mix of restrictions as
shower coverage diminishes through the day. Some improvement
may be seen Monday, but widespread MVFR ceilings are likely
through Tuesday. Tuesday night is when conditions go back
downhill again with a mix of restrictions likely as widespread
showers return. Improvement is expected again on Wedensday, but
the timing is more uncertain. Generally winds look light with
gusts less than 15kts.
&&
.MARINE...
Short Term...Winds and seas are expected to remain below SCA
criteria through Sunday morning. Winds will be out of the south,
with seas remaining below 5ft through Sunday. However, some
storms Saturday evening may bring some gusty winds over the
waters.
Long Term...Wind gusts and wave heights are below SCA criteria
in this forecast period as high pressure slides over the waters
on Monday. Winds are generally northeasterly through Monday with
a brief wind shift as a front moves over the waters on Sunday.
As high pressure moves over the waters Monday evening winds will
shift around more onshore through Wednesday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
NEAR TERM...Palmer/Schroeter
SHORT TERM...Palmer
LONG TERM...Baron/Schroeter
Area Forecast Discussion
National Weather Service Lake Charles LA
636 PM CDT Fri May 2 2025
...New AVIATION...
.KEY MESSAGES...
- A Severe Thunderstorm Watch has been posted for interior
Southeast Texas and portions of Central Louisiana though until
7:00PM CDT.
- SPC has placed Southeast Texas and central Louisiana in an Enhanced
risk for severe weather this afternoon and evening with the
rest of the area in a slight risk for the same period.
- Dry and slightly cooler air will move into the area Saturday
afternoon through Monday before a pattern change results in a
Slight Risk of excessive rain Tuesday
&&
.UPDATE...
Issued at 138 PM CDT Fri May 2 2025
Completed 18Z upper air data analysis illustrates the 1km capping
inversion has weakened with a nearly adiabatic lapse rate in the
sfc- 1km layer. Considering CIN is NIL, several cells will have
the potential to utilize present 4400J/Kg*K. Despite the lack of
shear aloft, strong updrafts supported by the CAPE and modest
7.0C/km sfc-3km lapse rate will be able to drive heavy rain /
hail cores. Thus primary severe threats likely to occur will be in
the categories of damaging wind and hail. This broadly aligns
with the 15Z RAP analysis earlier this morning which indicated
further destabilization through the the remaining afternoon
hours. Convective cells developing over SETX have increased
structural integrity into the early afternoon hours. A Severe
Thunderstorm Watch remains in effect for interior SETX and
portions of south Central Louisiana through 7PM CDT. Clustered
convective cells will have the potential to reach severe limits
through the late afternoon across the Watch area. Potential exists
for the watch to be expanded if early afternoon upper air
analysis indicates further destabilization and/or erosion of the
marine layer cap to the south and east- toward the lower Acadiana.
Kowalski / 30
&&
.SHORT TERM...
(Tonight through Sunday night)
Issued at 138 PM CDT Fri May 2 2025
A shortwave trough extends SW of the Great Lakes region this
afternoon with a relatively strong Jet Max across the Ozarks. This
wave will continue to amplify leading to large scale ascent
across the Southern Plains leading into the Lower Mississippi
Valley overnight. Weak low to mid level shear will help limit a
tornado threat through this evening. That said, a brief spin up is
not out of the question through mid evening hours. A cold front
boundary extending across the ARKLATEX region will laydown
convective showers / storms across the Gulf Coast overnight before
pushing offshore Saturday morning.
Behind the frontal boundary, winds will shift and pickup out of
the north. High pressure driving the dry airmass through the rest
of the weekend will lend milder highs, around 80F, and mostly
sunny skies across the CWA.
Kowalski / 30
&&
.LONG TERM...
(Monday through next Thursday)
Issued at 138 PM CDT Fri May 2 2025
The beginning of the work week will start of dry as the high
pressure airmass begins to modify across the SECONUS. Winds will
veer East during the afternoon and later increase, becoming
onshore southeasterlies by midnight Tuesday.
The midweek pattern is a bit unsettled with an non-stationary
Omega pattern draped across the CONUS. This results as the
aforementioned shortwave responsible for today`s convection,
wraps up into upper level closed low. Meanwhile an upstream
shortwave trough centered along the Southeast Alaskan fjords,
will amplify across the western CONUS through the weekend, also
forming a closed upper level low near the Four Corners region
Tuesday. Historically, these types of Omega blocks can lead to
persisting dry or wet conditions depending where the pattern
stalls. In this case, where this output has been supported by
global deterministic modeling over the past 48+ hours leads to
significant amount of Gulf moisture advection over SETX / SWLA
into the Southern Plains. As this moisture meets the quasi-
stationary frontal boundary Tuesday, WAA increases locally. Model
analysis and guidance indicates this boundary would be slow to
laydown over the TX / LA Gulf Coast through Thursday afternoon.
Hereafter surface troughing along the front appears to fill
through the end of the work week. Worth noting the onset of this
wet pattern now falls in the 5 day ERO outlook with a Marginal to
Slight Risk covering the entire forecast area on Tuesday.
Kowalski / 30
&&
.AVIATION...
(00Z TAFS)
Issued at 625 PM CDT Fri May 2 2025
Warm, moist airmass located over the northern Gulf states is
combining with a slow, southward moving cold front to bring about
widespread showery rainfall and isolated clusters of stronger
storms. Currently there are sub-severe thunderstorms near LCH and
AEX. Expect the same trend to continue into the evening and
overnight as the front sags southward. Showery rainfall with
periods of heavier rainfall, gusty winds and cells with hail and
frequent lightning.
North of the front, winds are variable but generally from the
north. A very slow turn from southerly winds to northwesterly
winds should take place throughout the TAF period. However, as the
front lingers nearby, winds can and will vary around the front
into the morning hours Saturday. Showery rainfall will continue
into the morning. As daytime heating commences, expect a round of
renewed convection.
The front should sag into the northern Gulf after 18Z resulting in
improving conditions thereafter.
11/Calhoun
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 79 53 78 / 80 30 0 0
LCH 66 82 57 81 / 80 30 0 0
LFT 67 81 58 80 / 70 60 0 0
BPT 66 84 58 83 / 90 30 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
SHORT TERM...30
LONG TERM....30
AVIATION...11
Area Forecast Discussion
National Weather Service Marquette MI
746 PM EDT Fri May 2 2025
.KEY MESSAGES...
- Light rain, potentially mixed with snow, will taper off
through this evening. The rest of the weekend will be dry.
- Warming pattern sets up this weekend into next week with highs
in the 60s and 70s, and lows in the 30s and 40s. RHs down to
30% or less possible over the interior west this weekend.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 251 PM EDT Fri May 2 2025
RAP analysis and GOES Satellite imagery reveal troughing extending
southwest from James Bay down to the southern Plains with multiple
embedded shortwaves. At the surface, a ~1000mb low pressure is
pushing northeast into central Quebec, while a weak inverted sfc
trough peels back into central Wisconsin. Broad synoptic lift,
upslope northerly flow, and CAA has kicked off light rain showers
across much of the CWA through this morning and early afternoon,
with light snow being reported earlier via the Herman, MI COOP
observer. Additionally, a recent ship observation from the Stewart
J. Cort reported a rain/snow mix while passing between the Keweenaw
and Isle Royale. Temperatures have struggled to crack 40 across much
of the northern lakeshore communities while temps hover near 50 in
Menominee county.
Through tonight, cloudy skies and light rain/drizzle will hang on a
bit longer, especially in the east-central UP where upsloping may
provide a slight boost to overall light QPF (<0.05"). Cant rule out
some light snow mixed in as temperatures slowly cool tonight.
Moreover, model soundings depict low-level moisture lingering across
portions of the Keweenaw and central/east UP where patchy fog could
develop.
Otherwise, skies will clear from west to east through daybreak as an
upper ridge and sfc high pressure nose into the Great Lakes. This
will introduce an extended period of much warmer and quieter
weather outlined below.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 251 PM EDT Fri May 2 2025
A stretch of quiet weather dominates the extended period, with high
pressure rolling into the U.P. starting Saturday. As the high moves
in, expect the remaining cloud cover to clear away, allowing sunny
skies to dominate by the afternoon hours. With warm air advection
occurring with the high pressure, expect temperatures to be much
more pleasant tomorrow, especially since the high will suppress
synoptic-scale flow across the area. That being said, with lake
temperatures over Lake Superior and Lake Michigan being around the
upper 30s and lower 40s respectively, expect a lake breeze to
develop near the lakeshores by the afternoon hours, bringing cooler
air to these areas. With the cool marine layer ceasing temperature
increases along the lakeshores, expect these areas to generally top
out in the 50s. Meanwhile, the interior west could see high
temperatures reach up to around 60, with the nearly calm winds
making it nearly a perfect day to enjoy a walk or hike. The one
concern we could see Saturday is RHs bottoming to around 30% in the
interior west by late in the afternoon. However, given that the HREF
shows only up to a 10% chance of this occurring, no fire weather
concerns are currently predicted at this time.
Going into Saturday night, expect the clear skies to allow
temperatures to plummet into the 30s across the interior areas,
although a light land breeze over the far west may keep things closer
to 40. Should the interior cool enough, given the recent
precipitation and wet conditions, we could see patchy fog form over
the area, particularly the south central.
Moving into Sunday, expect a very similar day in comparison to
Saturday. However, expect even warmer temperatures across the area
as warm air advection continues to funnel into the area as the high
begins to leave the area to the east; expect highs near the
lakeshores to increase into the 50s to low 60s as ENE to NE`rly
synoptic flow begins to take hold throughout the day, bringing the
lake breeze further inland over the central and east. However, in
the west, expect the highs to soar into the 70s, even as ENE to
NE`rly light flow moves through the area by the afternoon hours.
With conditions being a little drier over the interior west on
Sunday, we may see some widespread limited fire weather concerns
over the interior west by the afternoon given that RHs look to
approach 30% for a minimum. Taking this, the increasing winds, and
the warmer temperatures into account, we could flirt with a more
widespread limited to isolated-in-spots elevated fire weather event
in the interior west Sunday afternoon. The one saving grace is the
fairly recent precipitation keeping things fairly soggy across the
area. In addition, model guidance does seem to keep RHs a few
percent higher than compared to the previous forecast. That being
said, will continue to keep a close eye on the RH forecast. Expect a
pretty similar Sunday night in comparison to Saturday night,
although low temperatures are probably going to be a little bit
warmer as clouds will begin to build into the south central and east
late.
A low pressure lifting from the Ohio Valley into Lower Michigan
early next week is expected to bring scattered to mostly cloudy
skies across the area Monday into Tuesday. While guidance shows
remnant high pressure holding across the Upper Midwest early next
week, there is a non-zero chance that we could see some light rain
across the south central and east Monday into Tuesday (10 to 25%
chance according to the NBM). With the cloud cover moving overhead,
we may see high temperatures more muted on Monday in comparison to
Sunday, but we should still see up to the 50s along the lakeshores
to at least the 60s in the interior areas. In addition, limited fire
weather concerns could reappear on Monday, but with the increase in
cloud cover and slight increase in moisture, this isn`t as likely to
occur. The zenith of the warm air advection looks to reach us
Tuesday as 850mb around 10C translate to high temperatures of around
60 along the Great Lakes to the lower to mid 70s in the interior
west, especially as the cloud cover retreats from the U.P. from west
to east throughout the day as the low moves towards Ontario.
While model guidance does continue to spread next week, there is a
general agreement that a cold front (more than likely dry) will push
through the U.P. from the north around Wednesday. As this occurs,
expect temperatures to fall back down to below normal for early May,
with highs Wednesday only getting into the 50s to lower 60s. As high
pressure builds over the Upper Midwest late next week, expect clear
skies and warming temperatures to end the extended period. Looking
through next weekend to the week afterwards, the CPC shows us having
greater chances for both warmer than normal and drier than normal
conditions. This may be a concern through the rest of Spring as this
could create worsening fire weather conditions over the U.P.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 744 PM EDT Fri May 2 2025
Low level moisture has been slow to scatter out this evening with
IWD being the only one fluctuating between MVFR and VFR at this
time. Elsewhere, MVFR is lingering at CMX, while SAW is still
reporting LIFR cigs. The trend is toward clearing at both IWD and
CMX over the next several hours. However, the stratiform will be
slower to scatter out of SAW where IFR/MVFR is expected through the
night. In addition, will carry a brief period of MVFR fog early
tomorrow morning at CMX after skies clear out.
&&
.MARINE...
Issued at 251 PM EDT Fri May 2 2025
Outside of some southwest winds around 20 to 25 knots by Isle Royale
on Saturday, expect the light winds of 20 knots or less to continue
across Lake Superior this weekend as high pressure rolls through the
region. Even as a low lifts from the Ohio Valley into Lower Michigan
Monday and Tuesday, expect remnant high pressure ridging over the
Upper Midwest and Upper Great Lakes to keep the winds at 20 knots or
less Monday and Tuesday early next week. It won`t be until a cold
front pushes down from Canada around Wednesday that we could see
north to northeasterly winds of 20 to 25 knots back across Lake
Superior again. Light winds dominate the rest of the week behind the
cold front as high pressure sets up over the region.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...BW
LONG TERM...TAP
AVIATION...TDUD
MARINE...TAP
Area Forecast Discussion
National Weather Service New York NY
1100 PM EDT Fri May 2 2025
.SYNOPSIS...
A cold front slowly approaches and stalls nearby into Sunday.
A large cut-off low pressure system will bring unsettled
conditions to the area from the weekend through at least mid
week. High pressure may move in for the end of the week.
&&
.NEAR TERM /THROUGH SATURDAY/...
Forecast remains on track with only minor adjustments to account
for the latest observations. An area of showers and
thunderstorms over northwester PA is moving northeast and should
make its way into our forecast area by around midnight. Last few
scans on radar show some weakening, but isolated thunder cannot
be ruled out as it move through.
For tonight with the region clearly in the warm sector look for mild
and slightly humid conditions. Closer to the immediate shore,
especially early on in will be a bit cooler with an onshore wind.
Wind lighten during the night with well above normal temperatures
overall. Lows will mainly be in the lower half of the 60s across the
NYC / NE NJ metro, with mainly middle through upper 50s elsewhere on
a light S flow. Regarding precip chances there is some instability
indicated by mesoanalysis, especially just upstream and also revealed
in the mid levels via BUFKIT fx soundings. With the loss of daytime
heating any shower activity will be random due to a lack of forcing.
Cannot totally rule out a random shower / thundershower popping up
during the night with mainly slight chance PoPs.
During Saturday look for a good start to the day, with mainly
partial sunshine and it will warm up once again like the previous
day. With the cold front drawing closer the synoptic flow out of the
south should increase some. This will have coastal communities
cooler down a bit earlier in the day compared to the previous day.
There will be a rather large spread in temperatures by later in the
afternoon with inland locations towards and west of the NYC / NJ
metro getting into lower and middle 80s once again, and closer to
the coast residing in the 70s, and 60s closer to the immediate
coast. The Storm Prediction Center (SPC) has mainly the western
third of the CWA, mainly from the city and the Hudson River more or
less to the west in a marginal risk of severe weather to begin the
weekend on Saturday. The latest mandatory levels forecast of mass
fields indicate some ridging, mainly further aloft for eastern
portions of the region. This helps to explain why CAM guidance is
showing convection, especially organized quasi-linear convection
having difficulty moving further east later Saturday and Saturday
night. This results in going with a PoP profile that has likely and
categorical PoPs across the more NW portions of the area, with PoPs
trailing off further east and south. There are discrepancies in the
severe indices, especially with regard to CAPE later Saturday and
Saturday evening. The RAP and NAM 3km guidance indicated CAPE
approaching and exceeding 1000 J/kg, with other guidance showing
less CAPE with this all being location dependent. For now have gone
with enhanced wording of gusty winds and small hail with any
convection that initiates Saturday afternoon and evening. The
convection will attempt to initiate along a thermal pre-frontal
trough in the afternoon and evening. Since the cold front is progged
to stall just to the western border of the CWA, there remains how
far east any organized convection and steadier rainfall will get.
Thus have maintained chance to even slight chance PoPs along with
slight chance thunder further east across the area.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
Any convection should gradually dissipate Saturday night with the
region still being east of the cold front it will be rather mild and
a touch humid with cloud cover lingering. Look for minimum
temperatures to be similar to the previous night with mainly middle
50s to lower half of the 60s. Some patchy fog may even form, more so
where any convection occurred previously during the evening.
On Sunday look for clouds to linger with a S to SE onshore flow. Low
pressure becomes more or less vertically stacked back to our WSW.
This will gradually draw closer during the second half of the
weekend. Most guidance keeps the region primarily dry through the
morning and perhaps the start of the afternoon. By later in the day
PoPs increase as per NWP as moisture begins to lift north from the
south. Moisture begins to advect in off the ocean and rain chances
increase later in the day. There remains uncertainty as to how far
north and where the moisture advection access sets up. For this
reason, have chosen to begin main lower end PoPs earlier in the day,
then raise PoPs throughout the afternoon to mainly chance, and
likely across western areas. WPC has placed mainly the western half
of the area in a marginal risk of excessive rainfall for both
Saturday and Sunday. See the hydrology section for further details.
With thicker cloud cover overall and a bit more of an easterly
component to the near sfc winds, have temperatures mainly in the
upper half of the 60s, to the middle 70s across inland locations on
Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The extended period will be dominated by a large cut-off low
pressure system which will bring periods of rain, possibly with
embedded thunderstorms, from the weekend through at least the middle
of next week.
The large cut-off mid-level low spinning nearly stationary over the
Ohio Valley on Sunday night will allow for a surface frontal system
to develop downstream, just to our west. This frontal system will
likely set up and evolve in such a way that our area will be under a
deep southerly flow for the better part of next week. Meanwhile, a
mid-level ridge to the east will allow for a surface high pressure
system to prevent the progression of the cut-off low and enforce a
S to SE flow much of the period.
Global models have some agreement in allowing for a continuous
stream of moisture moving over the area allowing for periods of
widespread light to moderate rainfall Sunday night through Tuesday
night of next week. There still remains some uncertainty as to how
much of the ridging to the east is able to dry out parts of the
area, but at a minimum it should allow a gradient of the heaviest
and more persistent rainfall through the period with eastern areas
receiving less rainfall than western areas.
There may be enough instability during this timeframe to allow for
some embedded thunderstorms to develop as well, and given the deep
moisture profile under a southerly flow, heavy rain will be possible
in any storm or convective cells. WPC has the area in a marginal
risk for excessive rainfall for Monday through Wednesday morning
with a widespread 1-3 inches of rainfall over the area over the next
5 days with lesser amounts for eastern areas and higher amounts for
the west. Any thunderstorms may allow a locally higher rainfall
total of near 4 inches through the next 5 days.
The low pressure is expected to move out of the area sometime
Wednesday night through Friday morning. Models differ on the cut-
off`s reintroduction to the mean flow and as a result opted to keep
at least slight chance PoPs through the timeframe to account for the
uncertainty in its departure, though its possible that high pressure
builds into the area by Friday.
Despite ample cloud cover and rainfall, temperatures through the
timeframe should be fairly seasonable to slightly below average,
with highs each day generally in the 60s, possibly a bit warmer for
the NYC metro. Lows each night will remain in the 50s, courtesy of
the ample amounts of moisture.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
A cold front over the eastern Great Lakes will drop slowly SE
through Saturday, stalling near or just NW of the terminals
Saturday night.
An area of showers and thunderstorms over northeast PA moving
northeast looks to impact KTEB between 04-05Z. It does appear to
be weakening as it progresses NE and have included a VCSH for
this, but may have tempo SHRA or TSRA with unscheduled
amendment. KEWR is farther south and is less likely to see
impacts from these showers and thunderstorms, so may include
VCSH with unscheduled amendment here. It could affect KSWF and
KHPN between 05-06Z.
Mainly VFR through the TAF period with a brief period of IFR/MVFR
across the eastern terminals late tonight into daybreak Saturday
in low clouds/fog. With the current lack of any fog east of the
terminals (Rhode Island, Massachusetts, and the eastern
waters), there is just a low chance of these conditions
spreading farther west than is freakiest (as far west as KJFK,
KLGA, and KHPN). An isolated shower or thunderstorm is possible
during the time, but the best chance will be at KSWF from
20Z-24Z Saturday with the cold front.
Winds diminish to less than 10 kt this evening and in some
cases become light and variable. Occasional gusts of 15 to 20 kt
are possible through 01Z at KEWR. S winds will then ramp back
up Saturday morning and afternoon, with gusts of around 20 to 25
kt at most terminals.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
KJFK may be sustained for a time around 20kt late this
afternoon.
An isolated shower or thunderstorm is possible through the
period.
Low-level winds overnight may become light easterly.
There is a low chance of IFR/LIFR at KJFK and KLGA from 09Z-12Z
timeframe.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday Night: MVFR or lower in Showers/tstms across mainly the
metro terminals and points north and west.
Sunday: Chance of MVFR or lower in showers/tstms. Best chance
will be in the afternoon and nighttime hours.
Monday: Showers/tstms likely with MVFR or lower cond expected.
E-NE winds G20-25kt.
Tuesday: Showers/tstms likely with MVFR or lower cond expected.
SE winds G15-20kt.
Wednesday: Chance of MVFR or lower in showers.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Sub small craft conditions for the non-ocean waters tonight, with
the ocean waters experiencing small craft conditions much of the
time with gusts to 25 kt marginal small craft seas. By early
Saturday morning sub advisory conditions return briefly before small
craft conditions return out on the ocean for Saturday afternoon and
evening. There will be a chance of thunderstorms, more so on the
western waters Saturday evening. Sub advisory conditions will then
return early Sunday morning and should last through the day with a S
to SE flow at around 10 to 15 kt.
Generally sub-SCA conditions are expected after Sunday night, but
there may be occasional near-SCA gusts and wave heights on the ocean
nearing 5 feet Monday and then again on Tuesday.
&&
.HYDROLOGY...
WPC has placed mainly western portions of the area in a marginal
risk of excessive rainfall during Saturday and Sunday. At this time
mainly minor urban nuisance related flooding is expected in relation
to any thunderstorms that develop mainly across the western half of
the area as antecedent conditions are a bit drier than normal in
much of the area.
Long duration rainfall this weekend through midweek will likely
result in a widespread 1.5-3 inches of rainfall, possibly locally
higher in any thunderstorms. The higher rainfall amounts are
expected to be for the western half of the area. WPC has the area in
a marginal risk for excessive rainfall Monday through Wednesday
morning. While flash flooding isn`t expected, minor urban or poor
drainage flooding is possible at any point Saturday night through
Wednesday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ350-353.
Small Craft Advisory until 4 AM EDT Saturday for ANZ355.
&&
$$
SYNOPSIS...JE/MW
NEAR TERM...JE/JP/MW
SHORT TERM...JE
LONG TERM...MW
AVIATION...JP
MARINE...JE/MW
HYDROLOGY...JE/MW
Area Forecast Discussion
National Weather Service Pendleton OR
858 PM PDT Fri May 2 2025
.UPDATE...Northwest winds were increased across the Kittitas
Valley with this evening`s forecast update to better capture the
developing pressure gradient along the Cascades associated with
the incoming upper level trough Saturday afternoon/evening. The
presence of a vorticity max within the incoming trough should also
aid in wind gusts reaching advisory criteria. Further confidence
is gleaned from the NBM, which suggests a 60-80% chance of gusts
reaching 45 mph or greater. Thus, a Wind Advisory has been issued
for the Kittitas Valley from 1 PM to 9 PM Saturday.
Other minor edits were conducted regarding cloud cover,
temperatures,and humidities to better reflect current
observations. 75
&&
.PREV DISCUSSION... /issued 451 PM PDT Fri May 2 2025/
Updated for Aviation...
SHORT TERM...Today through Sunday...
1. Isolated thunderstorms both today and Saturday afternoon
2. Breezy daytime winds through the weekend
3. Return to dry conditions Sunday afternoon
Current short term 500 mb RAP shows the leading edge of the upper
level trough steadily pushing the upper level ridge off to the east.
Satellite shows the front to currently making its way onshore
bringing the beginning of the precipitation to the western portion
of OR & WA. Satellite also shows the beginning of some cumulus
formation in southern Deschutes County as well as ground
observations showing the winds to be increasing. Southwesterly flow
aloft will continue to flow into the region. Raw ensembles do show a
20% probability of thunderstorms beginning over the next few hours
through central OR steadily moving northeast into Jefferson, Wasco
Wheeler, Crook and Grant Counties. As the heat from the day
dwindles, models show the thunderstorms to settle and rain to
continue through the overnight period. Looking at the raw ensembles
data, 30-60% of the raw ensembles show that the 24 hour
precipitation for central OR and portions of the eastern mountains
will see 0.15-0.20 inches of rain, while N central and the lower
elevations show 40-60% chances of seeing 0.05-0.15 inches of rain.
Moving into Saturday, probabilities of thunderstorms decrease to
over the far eastern mountains and drop to 10-15% probabilities. As
for the rain amounts, there is a 40-70% probability of an additional
0.10-0.15 inches of rain for central, north central, foothills of
the Blues and the eastern mountains.
Not only is there the probabilities of thunderstorms, there is also
the probabilities of breezy winds along with the frontal passage.
Looking at the raw ensembles, there is a 30-50% probability of the
Simcoe Highlands (Goldendale, Centerville) and portions of the Gorge
seeing winds as gusty as 40 mph through the evening. Models show the
front to continue to pass over the region and increasing the
probability of winds again Saturday. The aforementioned areas will
have the same probabilities as today and then the Yakima/Kittitas
Valleys will see 30-60% probabilities of seeing 40 mph gusts with
some isolated areas seeing 60-80% probabilities (mostly along the
ridgetops) and then 30-45% probabilities along the southern Blue
Mountain foothills. Sunday as the trough will continue to move to
the east as the leading edge of another upper level ridge makes its
way towards the region.
Sunday models show the trough to steadily move east and drying out.
There will be lingering showers over the Wallowas Sunday morning
with some light snow falling above 3200 feet and rain below. Raw
ensembles show 40-70% probabilities of 0.10-0.15 inches of rainfall
over Wallowa County Sunday morning before the region dries out. The
remainder of Sunday will be dry across the CWA as the system
continues to move off to the east. Bennese/90
LONG TERM...Monday through Friday...Models are in excellent
agreement in having a ridge over the area through the first half of
the long term period then have some minor differences about some
weak disturbances in a southwesterly flow aloft Wednesday through
Friday as the ridge moves off to the east. The Extreme Forecast
Index indicates limited weather impacts next week. It does indicate
strong and gusty winds Monday afternoon focused on the eastern
mountains and the Grande Ronde Valley with a value of 0.94. The
other highlight is warm temperatures Tuesday through Thursday with
values of 0.72 to 0.81.
Monday morning will see a trough over Montana moving off to the
east. A ridge will be building offshore with a northerly flow over
the area. The ridge will remain in place through Tuesday afternoon.
It should be sunny and dry both days. Tight pressure gradients
between the departing trough and the building ridge will lead to
breezy northerly winds of 10 to 20 mph Monday afternoon. The Grande
Ronde Valley will reach 20 to 30 mph with gusts to near 40 mph. At
this time, it appears that conditions will remain below wind
advisory levels, but this will have to be watched this weekend.
Tuesday will see much lighter northeast winds under 10 mph over the
area. Temperatures Monday will be in the upper 60s to mid 70s with
60s in the mountains. Tuesday will warm to the mid 70s to lower 80s
with upper 60s to lower 70s in the mountains.
On Wednesday, an upper trough will descend out of the Gulf of Alaska
to the British Columbia and Pacific Northwest coast and this will
push the ridge off to the east. A warmer southwest flow will develop
and this will warm temperatures about 5 degrees to the lower to mid
80s with 70s in the mountains. There will be a marine push through
the Cascade gaps in the afternoon and winds will increase to around
20 mph in the Kittitas Valley and the Columbia Gorge. The trough
will send a weak front ashore in the evening and there will be a
slight chance of showers with barely measurable amounts of rain
along the Washington Cascade crest and the highest portions
of the northern Blue Mountains.
Thursday and Friday will see the southwest flow aloft continue. This
is a favored pattern for thunderstorms and the GFS has convective
afternoon showers over the eastern mountains, especially Wallowa
county each day. The ECMWF and Canadian have weaker convection
signals just on Friday afternoon. The NBM keeps the forecast dry
Thursday and has just a slight chance of showers over the Wallowa
and Elkhorn Mountains late Friday afternoon. Have followed the NBM
until the models get into better agreement on convection chances
late next week. Temperatures Thursday cool about 5 degrees to the
mid 70s to lower 80s with upper 60s to mid 70s in the mountains.
This will still be 6 to 9 degrees above normal. Temperatures
Wednesday warm back up 2 to 3 degrees. Perry/83
AVIATION...00Z TAFs...VFR conditions are expected, for the most
part, through the TAF period. The only possible exceptions will be
BDN and RDM which could see some MVFR Saturday morning.
Confidence is 50% at best, but enough to include in both
terminals. A trough and cold front is expected to move onshore
tonight and across the region on Saturday. These features will
bring the chances of SHRA, mainly overnight into the early morning
hours at all sites except YKM. Even YKM has low probabilities,
but low enough not to mention. Any SHRA should be over with by
midday or early afternoon. Then dry weather for the remainder of
the period.
Otherwise, gusty winds are expected at DLS through much of the
period, at RDM and BDN through tonight and at PDT and PSC Saturday
afternoon. Outside of these times, winds would generally be 10
kts or less.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 50 60 40 64 / 20 50 10 0
ALW 52 62 42 63 / 10 60 20 10
PSC 55 66 40 70 / 20 30 0 0
YKM 54 67 39 68 / 40 20 0 0
HRI 53 62 40 69 / 30 30 0 0
ELN 49 60 38 64 / 40 20 0 0
RDM 44 54 26 62 / 60 70 0 0
LGD 47 62 39 57 / 10 60 40 10
GCD 46 61 35 60 / 40 70 30 10
DLS 51 64 41 69 / 30 30 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...Wind Advisory from 1 PM to 9 PM PDT Saturday for WAZ026.
&&
$$
UPDATE...75
SHORT TERM...90
LONG TERM....83
AVIATION...77
Area Forecast Discussion
National Weather Service Tallahassee FL
837 PM EDT Fri May 2 2025
...New UPDATE...
.UPDATE...
Issued at 833 PM EDT Fri May 2 2025
No significant changes to the previous forecast appear necessary.
The HRRR runs so far this evening have an initial line of
thunderstorms knocking on the door of our western border counties
(Coffee, Geneva, and Walton) in the 6 am - 9 am CDT window.
&&
.NEAR TERM...
(Through Saturday)
Issued at 336 PM EDT Fri May 2 2025
Another round of fog development appears likely along/east of the
Apalachicola & Flint River Valleys during the early-morning hrs.
Some fog may once again become locally dense. Otherwise, expect
quiet weather with warm overnight lows in the low to mid 60s away
from the immediate coast. Attention then turns to the potential for
severe weather tomorrow as clusters of robust convection push
eastward across the Lower MS Valley. This activity is being forced a
cold front attendant to a digging shortwave trough from the Central
Plains. The latest Day 2 SPC Outlook expanded the Marginal Risk
(level 1 of 5) south and east to cover nearly the entire Tri-State
area, sans the Eastern FL Big Bend up to about Valdosta.
The environment will be somewhat favorable for isolated strong-to-
damaging wind gusts, small-to-medium-sized hail, and locally heavy
rain given modest shear/low-level jet amidst a moderately
unstable/anomalously moist airmass. Hi-resolution 12Z guidance shows
an initial convective wave pushing into the Western FL Panhandle
mid- to-late morning, followed by a second more widespread wave of
showers/thunderstorms in the afternoon from the Wiregrass Region.
Storms then appear to weaken some with eastward extent as we head
into the evening. Rain chances reflect expectations of better
convective coverage over the western half of the forecast area.
High temperatures also follow a similar pattern - low 80s: Central
Timezone counties; mid/upper 80s Eastern Timezone counties.
&&
.SHORT TERM...
(Saturday night through Sunday night)
Issued at 336 PM EDT Fri May 2 2025
As the slow moving trough/cutoff low continues to crawl eastward
throughout the short term, we`ll quickly see forcing for ascent
departing to the northeast Saturday evening into Sunday morning.
Placed under the base of the trough, we won`t see much forcing
for ascent on Sunday afternoon, especially as drier dew points
move in across the region from the north. Thus, activity is
expected to quickly wind down Saturday night into Sunday morning.
Skies will gradually clear out during the day on Sunday. Some
light redevelopment may occur over the FL Big Bend into southern
Georgia as the front fully moves through.
Expect daytime highs generally in the low to mid 80s with overnight
lows generally in the upper 50s to mid 60s.
&&
.LONG TERM...
(Monday through Thursday)
Issued at 336 PM EDT Fri May 2 2025
Once the cold front moves through the region on Sunday, ridging is
expected to build over the region as the slow moving cutoff low
spins to our north, leading to generally benign conditions through
midweek. Afternoon showers and/or thunderstorms along the sea breeze
will be possible, but limited in spatial extent due to large scale
subsidence. Thursday and into the weekend, another trough looks
to approach the region from the west leading to unsettled
conditions going into the weekend. We`ll have to keep an eye out
for any severe weather, but for now it looks like the region could
possibly be lined up for some much needed rainfall. Stay tuned.
Expect daytime highs generally in the mid 80s to low 90s with
overnight lows generally in the upper 50s to mid 60s.
&&
.AVIATION...
(00Z TAFS)
Issued at 714 PM EDT Fri May 2 2025
VFR conditions will prevail through this evening. During the
overnight hours, patchy fog and low stratus may develop, affecting
the ECP, DHN, and TLH terminals, bringing conditions to MVFR or
IFR levels. The fog will lift soon after daybreak. For the DHN and
ECP terminals, the fog will make way for a line of showers and
thunderstorms. Isolated damaging wind gusts and small hail will be
possible with these storms, along as frequent lightning and heavy
downpours, which could lower vsbys to MVFR. The storms will move
east through the day, eventually affecting all terminals but may
not reach VLD until after 00z Sunday.
&&
.MARINE...
Issued at 336 PM EDT Fri May 2 2025
Gentle to occasionally moderate southerly breezes continue
before becoming more southwesterly ahead of an approaching cold
front tomorrow night. Showers and thunderstorms become likely
Saturday afternoon and night, slowly exiting the area Sunday
evening. Winds behind the front become more westerly to northerly
Sunday, but become more variable as the front stalls near or just
south of our waters early next week. Seas will remain around 1 to
3 feet through the period.
&&
.FIRE WEATHER...
Issued at 336 PM EDT Fri May 2 2025
Fog tomorrow morning gives way to increasing chances for showers and
thunderstorms through the afternoon, especially along/west of the
Apalachicola & Flint River Valley. Some storms may be strong to
severe. A widespread wetting rain also appears likely. High
afternoon dispersions are forecast along the I-75 corridor thanks to
high mixing heights amidst brisk southwesterly flow.
Axis of greatest precipitation shifts to the eastern half of the Tri-
State area as the attendant cold front pushes through on Sunday.
Expect high afternoon dispersions nearly areawide. The airmass then
dries out heading into Monday as post-frontal northwesterlies take
over. Relative humidity values bottom out in the 30s away from the
immediate coast.
&&
.HYDROLOGY...
Issued at 336 PM EDT Fri May 2 2025
Generally an inch and a half or less of rainfall is expected across
the region over the next week, there are currently no flooding
concerns. Isolated higher amounts are possible within downpours,
which may leads to localized nuisance flooding in poor drainage
areas. A trough next week could look to increasing rainfall
accumulations across the FL Panhandle and SE Alabama, we could see
flooding concerns in these areas should next weekend`s system bring
significant rainfall.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 63 85 65 81 / 0 30 70 50
Panama City 69 80 66 81 / 10 70 80 20
Dothan 64 79 61 79 / 10 80 70 10
Albany 65 85 63 81 / 10 60 80 30
Valdosta 65 87 65 82 / 0 30 70 60
Cross City 64 85 65 81 / 0 20 60 80
Apalachicola 69 79 68 79 / 0 40 80 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 5 AM EDT /4 AM CDT/ Saturday for
FLZ108-112-114-115.
GA...None.
AL...None.
GM...High Rip Current Risk until 4 AM CDT Saturday for GMZ735.
&&
$$
UPDATE...DVD
NEAR TERM...IG3
SHORT TERM...Oliver
LONG TERM....Oliver
AVIATION...Montgomery
MARINE...Oliver
FIRE WEATHER...IG3
HYDROLOGY...Oliver