Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/22/24
Area Forecast Discussion
National Weather Service Denver/Boulder CO
820 PM MDT Fri Jun 21 2024
.KEY MESSAGES...
- Scattered to likely showers and thunderstorms through this
evening with heavy rainfall the main threat. Burn scars would be
most susceptible to flash flooding.
- Hotter and drier this weekend into early next week.
&&
.UPDATE...
Issued at 803 PM MDT Fri Jun 21 2024
Fairly uncertain forecast for the rest of the evening. Outflow
boundary has slowly been drifting south towards the Denver metro
over the past couple hours, but hasn`t provided enough lift for
any showers. Meanwhile, a second stronger outflow is moving across
northern Larimer county and has produced some showers/storms,
mainly north of the Wyoming border. Finally, some gusty
showers/storms are moving across Grand and Jackson counties.
Forecast guidance has struggled to resolve these features well.
Main adjustment this evening was to blend towards HRRR winds
through the night wind a push of gusty NW winds entering the metro
at some point this evening. Best chance of PoPs is across the high
country but can`t rule out a brief shower or storm for the metro
and plains. Otherwise, confidence is too low to make any
significant changes.
&&
.SHORT TERM /Through Saturday/...
Issued at 253 AM MDT Fri Jun 21 2024
Current radar shows scattered thunderstorms developing in the
Foothills moving eastward into the adjacent plains. Still some weak
capping evident over the central part of the plains with lacking Cu
development on satellite and MLCIN < -25 to -50 J/kg on SPC
mesoanalysis. Moisture is plentiful this afternoon with surface
observations showing dewpoints in the upper 50s/low 60s for the east
and northeast plains. Scattered thunderstorms move eastward onto the
plains. If it warms or moistens a little more, the cap could break
and support more organized convection and a few severe storms. Hail
up to 1.5", local heavy rainfall, and gusts to 60 mph possible in
the severe storms. The higher chance for seeing a few stronger to
severe storms will be closer to northern border where there is
slightly higher instability, less of a cap, and more moist. A small
percentage of high-res CAMs show potential for another round of
showers/storms late evening. However, with lacking agreement among
models, it is pretty low confidence.
Colorado remains under an upper level ridge on Saturday. Subtle
height rises and weak synoptic subsidence build into the region and
the plume of above normal moisture shifts south. This will support a
drier day than the previous few days. Instability will likely be
marginal, if any (< 400 J/kg CAPE). This could support low coverage
showers and storms in the afternoon starting on the higher terrain.
Based on model soundings, it will be tough for any shower/storm to
maintain itself for long once it moves eastward onto the adjacent
plains. Profiles show mid-level moisture, but fairly dry at the
surface more likely resulting in a brief gust or light shower. High
temperatures will be a degree or two warmer than Friday with highs
in the upper 80s to around 90 for the urban corridor/plains, 70s for
the Foothills, and 50s/60s for the mountains.
&&
.LONG TERM /Saturday night through Thursday/...
Issued at 253 PM MDT Fri Jun 21 2024
This entire period will be dominated by an upper level ridge of
high pressure stretching across the Central/Southern Rockies and
Desert Southwest. There will likely be enough moisture trapped
under the ridge for isolated to scattered late day showers and
storms, but mostly over the higher terrain.
Sunday will feature hotter temperatures as we have light westerly
flow aloft and further warm advection. This will support high
temperatures pushing into the mid 90s across the I-25 Corridor and
plains.
Monday will likely be one of the hottest days of the next week,
with continued weak downslope flow, warm advection, and a dry
airmass. 700 mb temperatures near 19-20C suggest high
temperatures will soar into the 95 to 100 degree range across the
plains and I-25 Corridor. Initial Heat Risk guidance would suggest
a Heat Advisory may be needed for Monday. With just enough
moisture and high lapse rates, would expect another round of late
day convection with scattered coverage in the mountains, but
isolated in the lower elevations with gusty outflow winds the main
threat.
There is a little uncertainty whether the hot temperatures will
stick around into Tuesday and Wednesday or if a little relief
occurs with a backdoor cool front. A shortwave moving across the
northern U.S. typically brings enough of a push to help. But some
models have trended weaker with that wave, but overall we think it
should still be enough to bring a couple degrees of cooling. That
said, above normal temperatures and highs in the lower 90s are
still likely for the plains. Convection could also see a bit of an
uptick with the trapped moisture under the ridge combined with
slightly better moisture behind the backdoor cool front.
Ensembles point to a weak wave or moisture surge from the south
on Thursday which could keep more convection in the forecast for
another day. Then, hotter and drier conditions may reestablish
themselves by Friday under the domination of high pressure.
&&
.AVIATION /00Z TAFS through 00Z Saturday/...
Issued at 544 PM MDT Fri Jun 21 2024
VFR through the TAF period. A couple things to note in the near
term. A weak outflow boundary is situated near FNL-GXY and is
slowly sinking south. This could bring a brief/weak wind shift to
DEN/BJC this evening. High-resolution models support this but are
also struggling with convection (and the lack of convection) to
the north. Similarly, another round of weaker showers is possible
later this evening but confidence in this is also pretty low at
the time. Will need to watch trends this evening to see if
either/both of these features will be more impactful than the
current TAF suggests.
Quiet weather is expected overnight with generally light drainage
flow. Winds will remain weak tomorrow and shift towards the
north/northeast in the afternoon. High-based, gusty showers will
be possible in the later afternoon hours. Overall coverage looks
fairly low at this time.
&&
.HYDROLOGY...
Issued at 253 AM MDT Fri Jun 21 2024
There will be a threat of flash flooding with the convection this
afternoon and evening. Precipitable water values are quite high
and the storms should produce heavy rainfall. However, the
thunderstorms will be moving at 20-30 mph to the northeast which
will lessen the threat of flooding. The alpine burn scars should
be most susceptible to the flash flooding threat as well as areas
of training thunderstorms.
No threat for flash flooding over the burn areas Saturday.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Hiris
SHORT TERM...Mensch
LONG TERM...Barjenbruch
AVIATION...Hiris
HYDROLOGY...Barjenbruch
Area Forecast Discussion
National Weather Service Billings MT
649 PM MDT Fri Jun 21 2024
.UPDATE...
Have cancelled all counties from a Severe Thunderstorm Watch.
A few factors greatly hindered our convection today: the low
stratus w/ capping, dry mid level air in our west, and a lack of
forcing. That said, there is a very weak mid level wave
approaching our west, and as a result we have seen some weak
convection develop just recently near the Crazy Mountains and
south of Billings. The potential for showers and non-severe storms
will continue thru the evening, and even a bit overnight in our
east, but the severe risk is greatly diminished at this point. JKL
&&
.DISCUSSION...
Through tonight...
Severe Thunderstorm Watch has been issued through 02Z for
Wheatland, Golden Valley and Musselshell Counties. Watch may be
extended further S later this afternoon. Good setup for severe
weather with strong trough overhead, surface CAPES of 1000-2000
J/kg, Bulk Effective Shear 35 to 50 kt and PWAT`s around 1 inch
with higher values over SE MT. Main threats are wind gusts to 70
mph and large isolated hail of 2 to 3 inches in diameter. A
tornado or two cannot be ruled out, but 0-1 km SRH has been
decreasing with successive HRRR runs, so this is a very isolated
threat. Watch may be extended S into Yellowstone and nearby
counties later this afternoon as low clouds scatter out.
Watch also issued for Sheridan County and Big Horn County til 03Z
given an uptick in activity there. Main threats are damaging
wind gusts to 70 mph and large hail with diameter up to 2 inches.
Arthur
Saturday through Thursday...
Upper level ridging will settle in over the Northern Rockies on
Saturday, resulting in hot and dry conditions with several
locations nearing record highs. High temperatures will be in the
90s for much of the region with locations along the river valley
most likely to hit 100 degrees (40-80% chance). A brief shortwave
will flatten out the ridging Sunday evening, bringing the chance
for isolated showers and thunderstorms. Westerly flow and ridging
will rebuild into the new week with high temperatures in the upper
80s and low to mid 90s. Latest ensemble runs show a broad trough
dipping into the PNW on Thursday. With this, high temps closer to
normals are forecasted and an increase in the chance for
precipitation (20-40%).
Matos/TS
&&
.AVIATION...
Isolated showers and thunderstorms will impact the area thru the
evening, and even a bit overnight in the east, but the risk of
severe thunderstorms has greatly diminished. Local MVFR is
possible in any stronger showers or storms. Fog is possible
overnight, especially east of the foothills, though there is only
a 10-20% chance of fog impacting a TAF site. VFR will prevail on
Saturday. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
Sat Sun Mon Tue Wed Thu Fri
-----------------------------------------------------------
BIL 056/085 058/098 062/091 057/085 057/091 061/089 060/080
21/U 01/U 11/U 00/U 00/U 11/B 23/T
LVM 051/085 053/094 056/089 051/087 052/091 055/087 053/077
21/U 01/N 11/N 00/U 01/U 13/T 34/T
HDN 054/085 057/101 061/092 055/086 056/093 059/092 058/082
41/U 01/G 21/U 10/U 00/U 11/U 33/T
MLS 056/082 058/096 065/088 058/083 057/090 061/090 060/083
50/U 00/U 20/U 10/U 10/U 11/U 32/T
4BQ 056/083 058/098 066/091 058/084 057/093 061/094 061/085
40/U 00/U 10/U 10/U 10/U 11/U 22/T
BHK 055/081 055/093 063/087 054/083 053/088 057/089 058/085
41/U 00/U 10/U 10/U 11/U 11/U 32/T
SHR 051/083 054/096 061/094 054/085 055/091 058/092 055/084
52/T 00/U 11/U 10/U 00/U 11/U 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Charleston SC
939 PM EDT Fri Jun 21 2024
.SYNOPSIS...
Tropical low pressure will move onshore along the Northeast
Florida and Southeast Georgia coast tonight. High pressure will
then become the primary feature this weekend and into next
week.
&&
.NEAR TERM /THROUGH SATURDAY/...
The observed 0Z KCHS sounding observed CAPE between 2000 to 2500
J/kg and PWAT values around 2.2 inches. Recent radar trends
indicate greater coverage over portions of the Charleston Tri-
County area late this evening. The forecast update will indicate
higher PoPs along the I-26 corridor through midnight.
As of 930 PM, regional radar indicated that the center of a
well defined tropical low was 10 to 15 miles off the coast, near
the FL/GA line. The center of the low is tracking towards the
FL/GA coast; NHC indicates that probs of a tropical cyclone
formation have decreased to 40 percent.
KCLX detected scattered to numerous showers across the forecast
area, greatest near the coast. Recent runs of the HRRR indicate
that the coverage of the inland showers will decrease through
the rest of this evening. Recent SPC Mesoscale Analysis
indicates CAPE values will remain above 1500 J/kg through
midnight. This lingering instability should support scattered
shower coverage this evening. After midnight, PW values will
surge up to 2.2 to 2.4 inches, especially near the center of
the tropical low. HREF indicates that a band of numerous to
widespread showers with embedded thunderstorms will develop
near and just north of the low center late tonight into early
Saturday morning. The combination of lingering instability and
high PWAT should produce a corridor of moderate to even heavy
rainfall south of the Savannah River. In fact, HREF indicates
the probabilities of the 3 hour QPF exceeding 1 inch may peak
at 70% with 30% chance of 3 inches.
QPF was increased to over an inch in spots, primarily between
McIntosh and Chatham Counties. Given the thick cloud cover and
rounds of rain expected overnight temperatures were kept
generally in the mid 70s. However the heavy rainfall over
southeast GA could result in wet bulb cooling, resulting in some
locations getting into the low 70s.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
Saturday and Saturday night: Aloft, the forecast area will sit
on the eastern extent of the upper ridge. At the surface, the
main feature of interest will be the remnant circulation of the
tropical disturbance that pushed inland along the northeast
Florida and southeast Georgia coast. This circulation and the
envelope of deep moisture associated with it will linger near
the Georgia coast and will be the focus for thunderstorm
activity likely ongoing at the start of the day. The highest
rain chances and greatest coverage of thunderstorms is expected
to be across the Georgia coastal waters, southeast Georgia, and
up along the Savannah River into southeast South Carolina. Rain
chances peak in the 60 percent range, but could certainly need
to be higher depending on how things evolve overnight. This will
yield the possibility of some locally heavy rainfall, given the
presence of the circulation, deep moisture, and potential for
training storms. For this highlighted area, rainfall amounts of
0.50-1.00" will be common, with potential for locally higher
amounts. Overnight, while the focus for nocturnal convection
should shift offshore, we could still see some showers and
storms periodically attempt to push onshore. Though the highest
chances are positioned over the waters, we do maintain 30-40
percent chances along the entire coast overnight. The presence
of clouds and the expected convection should keep temperatures
down a bit along the coast, with upper 80s common there.
However, further inland we could see some low 90s. Overnight,
lows will be typical of summertime with low to mid 70s.
Sunday through Monday: On Sunday, the remnant circulation should
completely dissipate or at least shift off to the northeast.
This should begin the transition to a more typical summertime
pattern as the subtropical high takes hold with a lee trough
inland across central Georgia and the Carolinas. Convection
should become more diurnal each day, favoring the afternoon and
evening time period. Temperatures will begin to increase as
well, with Sunday highs in the mid to upper 90s inland and low
90s elsewhere. Then by Monday, look for mid to upper 90s across
the entire forecast area. The result for Monday will be heat
index values rising to around 105 for much of the forecast area.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Aloft, the pattern will transition to weak and broad troughing
for much of the upcoming week. At the surface, the pattern
should be typical of summertime with subtropical high pressure
in control. Rain chances will be diurnal, with the highest
chances in the afternoon and evening and then transitioning
offshore to the coastal waters during the overnight periods. The
most notable part of the forecast will be highs in the mid to
upper 90s Tuesday and Wednesday, with a few inland locations
possibly hitting triple digits. For Thursday, mid 90s should be
more common then coming down to the low to mid 90s by Friday.
Depending on how dew point values work out, there could be some
heat index values into the 105-110 degree range Tuesday-
Thursday, primarily along the coastal corridor. If this comes to
fruition, Heat Advisories could be needed.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Prior to the 0Z TAFs, KCLX detected shower activity near or over
each terminal. Short duration restrictions are possible with the
occurrence of showers this evening. The potential for MVFR
conditions will be highlighted with a TEMPO from 0-4Z for KCHS
and KJZI. A band of at least moderate showers with embedded
thunderstorms is forecast to develop across the SE GA coast late
tonight with the landfall of a tropical low. The axis of this
convection will likely remain just south of KSAV. However, KSAV
will remain close enough that it may experience period of MVFR
conditions with showers between 5-9Z, highlighted with a TEMPO.
HREF thunder probs increase significantly toward daybreak Sat
across SE GA. In addition, forecast soundings and MOS indicate
MVFR ceilings with restrictions to visibility during showers and
thunderstorms. It appears that MVFR conditions will linger at
KSAV through much of the day, ending around 20Z.
Extended Aviation Outlook: Mostly VFR. However, convection will
bring brief flight restrictions, mainly each afternoon and
evening.
&&
.MARINE...
Tonight: Winds are certainly over performing a bit across the
coastal waters this afternoon with tropical low pressure
located just to the southeast of the Georgia offshore waters.
Enhanced winds will linger into this evening then diminish a bit
overnight as the low moves inland along the far northeast
Florida or southern Georgia coast. Winds/seas will diminish
first over the South Carolina waters, including Charleston
Harbor, and the Georgia waters late. However, there is uncertainty
on how quickly winds/seas will diminish, especially over the
South Carolina waters. The Small Craft Advisory has been
extended until 6 PM for the Charleston Harbor, 8 PM for the
South Santee- Edisto Beach nearshore waters and into the
overnight for the two Georgia marine legs. The highest seas will
occur early this evening, 4-6 ft nearshore and 6-8 ft over the
Georgia offshore waters.
Saturday through Wednesday: South to southwest flow mainly in the
10-15 knot range should prevail across the local waters through
the weekend and into the middle of next week. The exception
will be Sunday night into Monday when winds are expected to
increase a bit as the gradient tightens, with 15-20 knots more
common. Seas should average 2-4 feet through the period, though
perhaps up to 5 feet at times in the outer waters as winds surge
a bit.
Rip Currents: Onshore winds and lingering swell energy will help
to keep the rip risk elevated Saturday and again Sunday. For
Saturday, depending on the peak winds and the amount of swell
that arrives at the beaches, the local rip current calculator
results in a borderline high risk. Current approach is to
maintain the moderate risk for Saturday and allow the overnight
shift to re-evaluate.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until midnight EDT tonight for AMZ354.
Small Craft Advisory until 4 AM EDT Saturday for AMZ374.
&&
$$
NEAR TERM...NED/SVS
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...
Area Forecast Discussion
National Weather Service Hastings NE
602 PM CDT Fri Jun 21 2024
.KEY MESSAGES...
- Slight risk (level 2 of 5) for severe thunderstorms for
portions of central Nebraska this evening. Main timeframe is
5pm to midnight.
- Only low chances for thunderstorms (10-20%) Saturday through
Tuesday. Rain/t-storm chances increase again mid to late next
week.
- Heat returns early next week. High temperatures around 100
degrees are expected on Monday, and heat index values may
exceed 105 degrees in some spots.
&&
.DISCUSSION...
Issued at 318 PM CDT Fri Jun 21 2024
As of 3pm, radar shows a few thunderstorms already developing
over SW Nebraska, moving northeast. The expectation is that this
will continue to develop into a few clusters, impacting areas
north of Highway 6, mainly in the 5pm to midnight timeframe.
Convective parameters are not "off the charts" by any means, but
are at least marginally supportive of some supercell features
(1500 J/kg MLCAPE and around 35kt effective shear). Hail and
wind will be the main threats, but some localized flooding is
also possible. The 18Z HRRR shows some isolated maxima of 3.00"
of rain along the Hwy 92 area, but that is certainly on the
higher end compared to the 12Z HREF.
Northwesterly winds arrive on Saturday as a cold front moves
through the area. There is a low chance for a few showers or
storms to redevelop in our southeastern zones along this front,
but near-term models largely keep this to safely our southeast.
For many areas, tomorrow is expected to be the coolest day
through next week. Upper level riding moves into the area early
next week, allowing temperatures to climb into the 90s on
Sunday, and to near 100 degrees on Monday. There are low chances
for thunderstorms each of these days, but midlevel capping will
keep storms pretty isolated.
A series of upper shortwaves will break down the ridge and bring
us increasing thunderstorm chances from the middle to end of
next week. Temperatures return closer to climatology (upper 80s
and low 90s) for Wednesday/Thursday. Thursday through Friday
appears to be the next best chance for rain for most of the
area.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 1240 PM CDT Fri Jun 21 2024
Watching current radar trends along with HRRR output, decided to
shrink the VCTS timing for GRI as HRRR doesn`t bring the current
convection near GRI until 03z. There are a few pop-up showers
ahead of the convection that will have to be watched, otherwise
3-7z is best chance to see something. EAR I shrank the backside
by an hour as convection looks to be east of the TAF site by
then.21z HRRR generally keeps the convection north of I-80 this
evening. Southerly winds should taper off this evening and will
pickup and become NW around mid-day tomorrow as a cold front
will move through the area. The models are hinting at a MVFR
ceiling tomorrow morning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Mangels
AVIATION...Beda
Area Forecast Discussion
National Weather Service Gray ME
1032 PM EDT Fri Jun 21 2024
.SYNOPSIS...
A cold front will stall over Southern New England tonight
through Sunday as waves of low pressure ride along it. This
will result in near seasonable temperatures and rounds of
scattered showers and thunderstorms. Another front will then
cross on Monday with additional unsettled weather before high
pressure builds towards the middle of next week bringing warmer
weather.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1030 PM...Based on latest meso models and current radar lowered
POPS for much of the CWA through about 09-10Z, but kept the chc
POPS going along the boundary in the N, although these will
likely remain light showers overnight. Also did the usual
tweaking of T/Td based on current obs as well. Temps and Tds
generally lower than forecast, although there will be little in
the way of temp movement overnight except N of the boundary in
the Jackman-Rangeley area.
725 PM...Notable changes were mainly to POPS to keep things
drier across all all bu the N zones through this evening, except
far SW NW where showers have the highest chc of occuring this
evening. There is still a slight chance across much of the
area, but nothing significant for the rest of the CWA. I did
pull thunder out of the forecast for much of tonight
reintroducing toward daybreak as the weak low moves into srn New
England, but anything that does occur would be elevated until
after some warming occurs in the far S. Otherwise
temps/winds/sky adjusted to better line up with current obs.
The back door cold front continues to make progress
southwestward this afternoon, and is currently making its way
into southwest New Hampshire. Scattered showers continue to
develop along and behind the front, with clearing limited to
northeastern areas of the CWA. Temps have warmed into the mid
80s ahead of the front, allowing for some scattered
thunderstorms this afternoon, particularly in Cheshire county. A
strong storm can`t be ruled out either there, but most of the
strong to severe threat looks to remain to the south and west.
The front stalls to our southwest tonight, with rounds of
showers and storms moving along and to the north of the front.
The high res guidance continue to waiver on where the main
threat for the heaviest rainfall will be. The two main areas of
focus look to be across far southern NH near the Mass border,
with a second area through the higher terrain of New Hampshire
and into western Maine. There is some concern for the risk of
localized flash flooding tonight in these two areas, but it will
be highly dependent on whether or not convection begins to
train over the same areas overnight. As mentioned, the high res
guidance solutions continue to vary, but there is concern from
the general set up of a stalled front on the periphery of a
ridge.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
The risk for isolated flash flood concerns continue into
tomorrow as the front begins to slowly move northward as a warm
front again. Rounds of showers and storms continue through the
area around the periphery of the ridge. The flood threat again
would come from heavy showers and storms training over the same
areas over time. The whole day won`t be a washout, with breaks
of sun still likely through the day. There is also the risk for
some stronger storms across southwestern NH, which will be
located near the warm front by the afternoon hours.
There continues to be discrepancies in the high res guidance
tomorrow as well. The 3km NAM and HRRR keep much of the area
socked in with drizzle, showers, and highs in the low 60s. Other
guidance is not as dreary, with temps making it into the 70s
with more breaks of sun. This forecast rides the middle ground,
but acknowledges that some areas are likely to be cooler, and
others warmer, but tries to avoid a 10-15 degree bust for any
one spot.
The warm front makes slow progress through the forecast area
tomorrow night, continuing the concerns for localized flooding,
especially in areas that see most of the rainfall tonight and
tomorrow. The speed of the front will determine how much more
rainfall we see, but the current thinking is through the bulk of
it would be pushed north of the border by daybreak on Sunday as
another MCS rides along the ridge. However, any slowing of the
front would bring a greater heavy rainfall risk into our area,
so we`ll need to monitor this progress closely over the next
day.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Overview: Relatively progressive flow across the northern CONUS
with a broad 500mb trough across the region that will bring
shortwave trough passage and periods of storms through the week.
Potential for more prolonged ridging towards the end of next
week. This will bring periods of active weather with
thunderstorms and temperature swings from near normal to above
normal.
Impacts: Localized heavy rain is possible Sunday across Northern NH
and the Western Maine mountains. In addition, severe weather could
be possible across southern areas on Sunday dependent on how much
clearing occurs. Another round of possible strong thunderstorms is
possible towards mid-week.
Forecast Details: Sunday the stationary boundary becomes a warm
front and surges north of the area bringing the region back into the
warm sector, especially southern areas. Where the boundary sets up
and stalls will be a possible focus area for localized heavy rain as
strong moisture convergence is expected along the boundary and
forcing increases as a surface low develops along the boundary.
Threat for severe weather will increase as a robust mid-level
shortwave and associated cold front pushes through the area sometime
late Sunday. The big question is how robust the marine layer will
be in place and if it cane burn off in time. Monday the shortwave
trough swings through with the potential for much cooler weather and
showers, but this depends on the timing of the trough. Some
guidance is slowing the progression of the mid-level low which could
allow rain shower activity to linger into Monday evening. Tuesday
looks to have the highest potential for being the driest day of the
week as a shortwave ridge moves over the area with a rebound in the
temperatures back into the 80s. Wednesday could be warm once again
as a return to southwest flow is still expected ahead of the next
approaching trough from the Great Lakes. A period of storms is
possible in the Wednesday night into Thursday timeframe as the next
cold front swings through the area. Timing on this front still has
timing spread of 12 hours or so in the model guidance. Potential for
much cooler weather and Canadian high pressure by Friday next
week.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Scattered showers bring brief restrictions to New
Hampshire terminals into this evening, with mainly MVFR to VFR
ceilings elsewhere. Ceilings then lower to MVFR and IFR
overnight, with showers at times. Showers continue at times
tomorrow, with ceilings likely improving to MVFR tomorrow
morning. There are low PROBs for thunderstorms across southern
and western NH terminals during the afternoon. Ceilings lower
again tomorrow night to IFR in most spots, with showers and a
low PROB for a thunderstorm overnight.
Long Term...Showers and thunderstorms could bring temporary MVFR to
IFR conditions on Sunday with the highest threat across the
airfields of New Hampshire. Showers and storms could be possible
into Monday morning before drier weather returns Monday night
through at least Wednesday morning with VFR conditions
anticipated.
&&
.MARINE...
Short Term...Northeasterly flow continues behind a cold front
through tomorrow, with conditions remaining below SCA levels.
Patchy dense fog is possible tomorrow night as a warm front
lifts across the waters.
Long Term...Southerly winds increase over the waters on Sunday ahead of
an approaching cold front. Seas and winds could reach SCA level by
Sunday afternoon and last through the Monday morning. Cold front
swing through on Monday with a return to offshore through Tuesday
before winds increase along with seas once again by Wednesday from
the south again as another cold front approaches the region.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
SYNOPSIS...
NEAR TERM...Cempa/Clair
SHORT TERM...Clair
LONG TERM...Dumont
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service North Platte NE
641 PM CDT Fri Jun 21 2024
.KEY MESSAGES...
- There is a risk for severe thunderstorms tonight, generally from
Interstate 80 north.
- There will be a continued threat for excessive rainfall today and
tonight, mainly over portions of north central Nebraska.
- Drier conditions are expected this weekend with temperatures
approaching the century mark in SW Nebraska Monday.
&&
.SYNOPSIS...
Issued at 339 AM CDT Fri Jun 21 2024
H5 analysis from earlier this evening had high pressure anchored
over the central Appalachians. Further west, a trough of low
pressure was present from southern Washington state, south into
central portions of the California coast. Donwstream of this
feature, numerous embedded shortwaves were present from the Four
Corners, northeast into the central and northern Rockies.
Earlier this evening, a strong shortwave approached the Nebraska
Panhandle and is currently lifting into southern South Dakota
from Cherry County overnight. This feature, coupled with a
stationary front, draped over northern portions of Nebraska, led
to strong to severe thunderstorms earlier tonight. Tornadoes,
strong straight line winds and heavy rain were reported over
north central Nebraska. As of 3 AM CDT, thunderstorms have
decreased in areal coverage with light to moderate rainfall
occurring over portions of north central Nebraska.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 339 AM CDT Fri Jun 21 2024
The before mentioned shortwave, will slowly migrate northeast
into southern, then southeastern South Dakota this morning.
Precipitation will eventually end this morning across northern
Nebraska. In the wake of exiting convection, a frontal boundary,
currently draped from far southwestern into portions of south
central Nebraska will migrate north. The high res models
overnight seem to have the front located correctly while the
NAM12 and GFS solns have this feature too far north currently.
That being said, believe the front will migrate slightly north
today from its current position in line with the HRRR and NAM
Nest forecast today. By this afternoon, this feature will be
roughly from Ogallala to south of O`Neill. This frontal boundary
will combine with a second shortwave, set to push into
northeastern Colorado and the Nebraska Panhandle this afternoon,
and will be the focal point for thunderstorm development this
afternoon. As for the threat for severe storms the greatest
threat will be along and north of the frontal position. ATTM
this threat is greatest along and north of a line from Ogallala,
to North Platte, to Ericson. Decent deep layer shear this
afternoon along with surface dew points INVOF the front in the
upper 60s will provide ample support for severe storms this
afternoon and evening. Large hail and damaging winds will be the
main threats, however, as was the case earlier today, probably
can`t rule out a tornado INVOF the warm frontal boundary. With
the frontal boundary forecast to be slightly further south,
trended precipitation chances upward for this evening.
Thunderstorms this evening will force a cold front south of the
area overnight. This will shift the threat for thunderstorms
south and east of the forecast area for Saturday. Highs Saturday
will run 5 to 10 degrees cooler compared to Today`s forecast
highs.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 339 AM CDT Fri Jun 21 2024
Ridging will build into the western CONUS then central plains
Sunday into Monday. The latest guidance is indicating a good
potential for readings toping 100 degrees south of I-80 for
Monday. Based on forecast H85 temps, this looks plausible. A
northern stream disturbance will lead to cooler readings Tuesday
and Wednesday. Temps will then rebound upward Wednesday and
Thursday, as the ridge becomes re-established across the high
plains. The latest GFS is indicating decent potential for triple
digit heat once again in SW Nebraska for Thursday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 641 PM CDT Fri Jun 21 2024
Aviation weather concerns remain for western and north central
Nebraska terminals through the period, including gusty winds,
low ceilings, thunderstorms, and fog. Scattered storms are
ongoing east of the KLBF and KVTN terminals. A frontal passage
tonight will cut off precipitation, but winds will switch to
north/northwesterly. stratus and fog with ceilings below OVC010.
Fog will also develop after 06Z across north central Nebraska.
&&
.HYDROLOGY...
Issued at 339 AM CDT Fri Jun 21 2024
Based on rain totals of 3-5 inches along the highway 20
corridor from Ainsworth to O`Neil earlier tonight and forecast QPF`s
of 1 to 3 inches in these areas today into tonight, will hoist a
flood watch from now until 12z Saturday. This watch will include
Brown, Rock, Keya Paha, Holt and Boyd counties. Currently, the gauge
reading on the Elkhorn River at Atkinson is around 6 FT, which is
1.5 FT below the flood stage of 7.5 FT. Will need to monitor this
this morning. If this approaches flood stage, we may need to hoist a
flood advisory for the Elkhorn River in Holt county.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Saturday morning for NEZ006>010.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...Roberg
HYDROLOGY...Buttler
Area Forecast Discussion
National Weather Service Marquette MI
701 PM EDT Fri Jun 21 2024
.KEY MESSAGES...
- Patchy fog develops tonight, continuing into Saturday.
- Wet pattern continues tonight, becoming widespread rain
Saturday into early Sunday.
- The heaviest rainfall should stay south of the UP, but there
is still a marginal chance (5% chance) for locally heavy rain
resulting in minor flooding impacts across southern Upper
Michigan.
- Another round of showers/thunderstorms possible Sunday and
Monday night into Tuesday.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 353 PM EDT Fri Jun 21 2024
Current RAP analysis this afternoon highlights the mid level trough
out over the Canadian Prairie Provinces with a weak shortwave over
the UP and a deteriorating sfc high pressure over the Upper Great
Lakes. Sfc obs show the warm front has lifted into southern WI
already and WAA light showers light up the radar data across much of
the central and eastern UP. This round of showers continues moving
east across the UP with the weak shortwave, diminishing over the
east this evening. A brief dry period is likely in the north half of
the UP following this round of showers into tonight while isolated
to scattered showers continue over the south-central as an
additional weak shortwave traverses the UP supported by WAA. Showers
then increase from the south late tonight into Saturday ahead of the
main shortwave on Saturday. Given the ample moisture and light
easterly winds mainly below 10 mph, some patchy fog is expected to
develop tonight and continue into Saturday. Some rumbles of thunder
can`t be ruled out in the south-central through tonight, however
instability is lacking (6/21 12Z HREF mean MUCAPE stays around
100J/kg over Menominee County) and the frontal boundary will stall
out over central WI tonight so strong storms are not expected. Lows
are expected in the 50s with cooler temps in the Keweenaw and
eastern Lake Superior shores.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 304 PM EDT Fri Jun 21 2024
Deterministic and ensemble guidance packages continue to highlight
the potential for multiple rounds of showers and thunderstorms in
the extended forecast period as Upper Michigan sits primarily under
near-zonal to northwest flow aloft. During this period, daytime
temperatures will start off cool, but trend back into the 70s and
80s for the first half of the work week.
Beginning Saturday, surface low will lift northeast along a warm
front into the Great Lakes as a shortwave presses east through
Minnesota. This will support a deepening surface low Saturday
afternoon into early Sunday as the low transits Wisconsin and lower
Michigan. Precip along and north of the boundary will build into the
region through the day as PWATS remain 1.75-2 inches. Recent NBM and
LREF guidance suggests a high (>75%) chance of exceeding 1 inch of
rain across the southern half of the forecast area, with 30-60
percent chance across the north half. While most deterministic
guidance suggests a widespread 0.5-2 inches through Sunday morning,
GEFS and EC ensemble means suggesting the same supports the higher
confidence in a potential notable and widespread rainfall event.
This generally matches the EC EFI and SOT, which paints much of the
south half with 0.8-0.9 EFI and 2 for SOT, indicating a potential
extreme rainfall event outside of climatology. It should be noted
though, that even if widespread 1-2 inches of rain does occur,
recent RFC flash flood guidance suggests 2+ inches of rain in 1-6
hours would be needed to raise flash flooding concerns. Given that
this is not the case with this event, flash flooding is not a
concern. With that being said though, given recent rainfall, I`d
expect some ponding of water in low lying locations and some
additional river rises through the next few days if we do experience
this rainfall. Additionally, rainfall amounts will be dependent on
where the low tracks and where the warm frontal boundary stalls
across Wisconsin, which a general clustering analysis of the EC and
GEFS ensembles still suggests a range of locations. Model soundings
suggest a mostly capped atmosphere across the area, with some
elevated instability noted across the south. With this in mind, some
embedded thunderstorms can`t be completely ruled out, but strong or
severe thunderstorms aren`t expected at the moment. Daytime highs
Saturday should be in the 60s to near 70F while overnight lows dip
into the 50s to upper 40s across the forecast area.
Precip should end Sunday morning from west to east as the low pulls
away and weak mid-level ridging transits the area. This break
appears to be short-lived though, given the clipper-like shortwave
pressing southeast across Ontario/Lake Superior in the
afternoon/evening. The GFS and NAM suggest the morning rain should
end early enough to enable small daytime destabilization through the
day, which would support thunderstorms to accompany the
afternoon/evening wave. At the moment, strong or severe weather
aren`t anticipated.
High pressure over the area Monday should keep the region dry while
upstream, a ridge rolling impulse moves east through the
Dakotas/Minnesota and a surface low tries to develop. By Monday
night, precip chances increase for Upper Michigan as a cold front
extending south of a low moving through Manitoba and the low moving
through southern Minnesota press closer. These swing into the Great
Lakes on Tuesday. Ahead of the front, daytime temps could warm into
the 80s across much of the region Tuesday. High pressure and dry
conditions builds in Wednesday into Thursday. Beyond this, guidance
differs greatly on the timing and position of the next wave.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 701 PM EDT Fri Jun 21 2024
Next round of showers will move in overnight and will bring
deteriorating conditions with them. IWD will be MVFR tonight and
then IFR Saturday. CMX will be VFR until later tonight when fog
could develop and take them down to MVFR. By late Saturday
afternoon, rain moves in there with LLWS and MVFR condtions at
times. SAW will be VFR until later tonight when rain moves in and
then drops to MVFR. By late Sat afternoon, heavier rain and IFR/LIFR
conditions move in.
&&
.MARINE...
Issued at 304 PM EDT Fri Jun 21 2024
A deepening low pressure system will gradually lift into the region
tonight and Saturday, before exiting into Ontario Sunday morning. As
this transit occurs, expect winds to shift to northeasterly/easterly
across Lake Superior tonight before becoming northerly Saturday
night and northwesterly by Sunday morning. Light winds of 20kts or
lower are mostly expected in this event, although northeast winds
going down into the Duluth Harbor Saturday may climb to near 25 kts
at times. Additionally, as winds shift to the north Saturday night,
expecting an increasing to 25-30 knots across central and eastern
Lake Superior as the peak pressure gradient force shifts through.
Winds lighten to 20kts or less Sunday and predominately remain there
until at least Tuesday. At this point, expecting southerly winds to
increase to near 25 kts ahead of a transiting cold front.
Thunderstorms will be possible, mainly Sunday afternoon/evening and
then again on Tuesday. Winds may be erratic near these, but at the
moment, strong or severe thunderstorms are not expected.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Jablonski
LONG TERM...JTP
AVIATION...07
MARINE...JTP
Area Forecast Discussion
National Weather Service Nashville TN
855 PM CDT Fri Jun 21 2024
...New UPDATE...
.UPDATE...
Issued at 849 PM CDT Fri Jun 21 2024
Clouds will clear out tonight and we will see quiet conditions.
Temperatures are warm currently in the 80s which is about 2-5
degrees warmer than yesterday this time. Temperatures will remain
warm tonight falling into the low to mid 70s. A little bit of
patchy fog will be possible in the normal fog areas towards
daybreak but most areas won`t see anything. Another hot one is in
store for tomorrow with highs in the mid to upper 90s.
&&
.SHORT TERM...
(Rest of today through Saturday)
Issued at 1108 AM CDT Fri Jun 21 2024
Another hot and humid summer day across the midstate today with
current temperatures in the mid 80s to low 90s and dewpoints in
the mid 60s to low 70s. Anticipate highs to reach the upper 80s
to around 90 on the Plateau this afternoon with mid to upper 90s
elsewhere. HRRR has been consistently showing a few popup showers
or storms during the afternoon, so I added a very slight chance
pop for that potential. Tomorrow looks even hotter as the upper
ridge remains in place and 850mb temps heat up a tad, so expect
highs to be a degree or two above today`s readings. It`s possible
Nashville could squeak up to the 100 degree mark during the
afternoon, but right now I`m forecasting it to stay just below. A
few areas could also reach our Heat Advisory criteria of 105+
heat index values, but with most areas staying below that I`m not
planning on an advisory at this time. Also not anticipating any
popups tomorrow due to the strength of the upper ridge, but as
always in our summertime regime one or two could occur.
&&
.LONG TERM...
(Saturday Night through next Friday)
Issued at 1108 AM CDT Fri Jun 21 2024
On Sunday, a weak frontal boundary will sink down from the north,
bringing some widely scattered showers and storms by late
afternoon and especially Sunday evening/night. Models accordingly
cool down highs for Sunday, but with the late day frontal arrival
they are likely overdoing things and temps will likely be similar
to Saturday. Forecast soundings aren`t impressive with only weak
shear and CAPE for late Sunday, but a strong storm or two could
occur mainly with gusty winds.
Drier airmass moves in behind the front on Monday into Tuesday,
but 850mb temps actually warm up into the 21-24C range - so it
highs will actually go up across Middle Tennessee with a better
likelihood for a few areas to hit the 100 degree mark. Low level
moisture begins returning from the west on Tuesday so precip
chances will be on the rise Wednesday into Thursday while
temperatures decline thanks to clouds/precip. Guidance shows a
more substantial cold front moving through the region by late
week, with a return to dry conditions and at least somewhat of a
"cooldown" into the mid 80s to low 90s.
&&
.AVIATION...
(00Z TAFS)
Issued at 623 PM CDT Fri Jun 21 2024
VFR conditions will prevail over the next 24 hours. Winds will be
light and variable. Patchy fog may develop over portions of the
Cumberland Plateau, which may impact KSRB and KCSV. But confidence
was not high enough to include in the TAF.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 74 99 75 98 / 0 0 0 20
Clarksville 72 96 73 94 / 0 0 10 30
Crossville 67 89 68 89 / 0 10 10 20
Columbia 72 96 72 96 / 0 0 0 20
Cookeville 69 91 70 91 / 0 10 10 20
Jamestown 68 90 70 89 / 0 10 10 30
Lawrenceburg 71 95 71 95 / 0 0 0 10
Murfreesboro 71 97 72 97 / 0 0 0 20
Waverly 72 95 73 94 / 0 0 10 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......Mueller
SHORT TERM...Shamburger
LONG TERM....Shamburger
AVIATION.....Clements
Area Forecast Discussion
National Weather Service New York NY
1143 PM EDT Fri Jun 21 2024
.SYNOPSIS...
A cold front to the north of the region, slowly retreats back
north as a warm front this weekend. A cold front approaches late
Sunday, moving across Sunday night into Monday, followed by
high pressure on Tuesday. Another frontal system will approach
on Wednesday and move slowly across from Wednesday afternoon
into Thursday. High pressure will return for Thursday night into
Friday.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
Region remains on NE edge of southern ridging, with subtle
convectively induced vorts moving through flow. A cold front
over central New England sinks south towards the region this
eve, likely stalling just north of the forecast area late in the
day into night.
Much of the area is now dry, with a cluster of showers/weak
thunderstorms moving into the Lower Hudson Valley. This activity
is expected to continue to weaken as it moves eastward.
Otherwise, very warm and muggy conditions overnight, with lows
in the lower to mid 70s.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY/...
Upper ridge continues to sink south through the weekend, with
deep layer flow aloft backing from W to SW. At the surface, cold
front retreats north tonight and remains fairly stationary
across central and SE New England through the weekend.
Heat continues to build through the weekend, with 850mb temps
rising into the upper teens on Sat and 20-21C on Sun. Gusty SW
flow and deep mixing will have surface temps similarly
increasing each day away from the coast. High in the mid to
upper 90s likely for NE NJ, NW NYC, and surrounding portions of
LoHuD, with widespread upper 80s to lower 90s for remainder of
the area. A strengthening S/SW flow will limit south coastal LI
and SE CT in the lower to mid 80s each day. High temperatures
on Sunday could touch or break daily records across NYC/NJ
metro.
850mb TDs climb slightly Sat into Sun as well, indicating a
slight upward trends in surface Td`s as well, but still likely
some Td mixout in the afternoon during peak heating. This
expands the threat for 95 to 100 heat index into northern New
London/Middlesex and NW LI for the weekend, continuing from
today. Isolated 105 HI possible for NE NJ and immediate
surroundings Sat and Sun, but too low coverage/confidence for
upgrade to excessive heat at this time. T/Td trends will be
monitored thru the weekend for possible upgrade. Blend of
deterministic NBM and HRRR for T and Td seems to be verifying
well.
Focus for tstms Sat aft/eve looks less clear than today as warm
front pushes farther north into northern New England. Isolated
convective initiation possible along sea- breeze and off higher
terrain to the NW (drifting east) in moderate to strong
instability but still weak shear/mid level lapse rate
environment. More widespread convective development possible
along backdoor cold front moving westward across SE New England,
but this appears to stall east of the area, but could clip far
SE CT. For now, have capped pops at high chance for interior,
to slight/low chance for the coast, based on the above. Isolated
wet microburst potential with any convective development along
and north of these boundaries in moderate to strong instability
and weak shear/mid-level lapse rate environment.
A seemingly better chance for organized convection late Sun
into Sun Eve with lead shortwave ahead of digging Great Lakes
shortwave and pre-frontal trough approaching from the west. This
approaching system will strengthen wind fields and deep layer
shear over the region, likely promoting better organizing of
upstream convection and longer lived updrafts. Question is
timing of this convection into our area. Moderate to strong
instability is likely once again across NYC and pts N&W Sun
afternoon, but late day/evening timing of convection would not
maximize potential. Marginal severe threat from SPC looks
reasonable based on mismatch btwn shear/and peak instability
timing, and strong synoptic S/SW flow disrupting any clear focus
outside of elevation.
Low and localized flash flood threat both days with isolate to
scattered convective coverage on Sat, and likely better forward
progression of convection on Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Key Points:
* Heat wave comes to an end Sunday night-Monday with a cold frontal
passage.
* One more hot day expected ahead of another frontal system on
Wednesday.
* A slow moving frontal system could bring locally heavy rainfall
from late Wednesday into Thursday.
NBM was generally followed, with some adjustments mainly to to
temperatures and dewpoints per 12Z GFS and 00Z ECMWF guidance.
The heat wave should come to an end as an upper trough/closed low
and associated cold front approach the area Sunday night into
Monday. A few tstms with gusty winds possible Sunday evening via pre-
frontal deep layer unidirectional shear (mid layer SW-W flow 35-50
kt) and leftover steep lapse rates from daytime heat. Brief heavy
rain could also be possible with any storms.
Front clears the area daytime Mon, with any 90-plus temps shunted
just south into central NJ, and heat index values close to
actual temps.
Tue should be a bit warmer with high pressure and downslope W-NW
flow in control. High temps will range from 85-90 in most places,
with similar heat index values as afternoon dewpoints should be no
higher than the upper 50s/lower 60s. Wed will be a little warmer and
more humid still, with high temps 90-95 from NYC north/west and the
heat index approaching or just surpassing 95 for one day as
afternoon dewpoints increase to the lower/mid 60s.
A slow moving frontal system should bring an end to this shorter
spell of heat, with chances for tstms from late day Wed into Thu.
More on this in the Hydrology section.
Locally heavy rainfall possible with PW approaching 2 inches and
some potential for training cells along the slow moving frontal
boundary. Attm Fri looks dry with temps near or just above
the seasonal avg.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
High pressure remains across the Western Atlantic as a front
lingers north of the region.
Mainly VFR. Much of the area is now dry, with a cluster of
weakening showers/thunderstorms moving through the Lower Hudson
Valley. This cluster should continue to weaken, but could
result in brief MVFR conditions. Some patchy fog/stratus may
develop tonight for eastern terminals, but confidence in this is
too low to include in the TAF at this time.
Winds gradually lighten tonight, with similar flow and speeds
expected Saturday. Showers and thunderstorms are possible again
Saturday afternoon/evening. Thunders will likely be isolated and
confidence was too low to include in the TAF anywhere except
KSWF. PROB30 for SHRA was included elsewhere.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low confidence in any showers/thunderstorms making it to the NYC
terminals tonight. If they were going to make it that far east,
timing would be between 05z and 07z.
OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
Saturday Night: Mainly VFR. Showers and thunderstorms possible
in the early evening hours.
Sunday: Mainly VFR. Showers and thunderstorms becoming likely late
day into the night. S-SW wind gusts 15-20 kt.
Monday: Mainly VFR. Chance of showers and thunderstorms, mainly in
the morning.
Tuesday: VFR.
Wednesday: MVFR or lower at times with showers and thunderstorms
possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Conditions will remain below SCA levels through at least Saturday.
Marginal SCA conditions possible for ocean waters leading to NY
Harbor and surrounding near-shore waters with afternoon coastal
jet development and seas of 3 to 5ft.
Higher confidence in SCA for winds and seas on the ocean water
Saturday Night into Sunday as S-SW flow strengthens. Gusts
up to 30kt possible Sunday aft. Nearshore non- ocean waters may
see advisory gusts conditions as well Sunday aft.
SW flow 20-25 kt on the ocean with a few higher gusts to 30 kt
Sunday night will maintain significant wave heights of 6-8 ft
during that time frame, lowering only to 5-7 ft daytime Mon as
SW flow 15 kt continues. These seas should then gradually
diminish below 5 ft Mon night as a cold front passes and winds
shift offshore.
Conditions fall below small craft late Monday night into
Tuesday morning.
&&
.HYDROLOGY...
Isolated thunderstorms may produce brief heavy downpours that
could lead to brief nuisance flooding, but the threat for more
significant flooding this evening has ended.
Low and localized flash flood threat on Saturday with any slow
moving isolated to scattered tstm activity across interior.
Low flash flood threat late Sunday into Sunday Night with
possible scattered convection development along/ahead of pre-
frontal trough/cold frontal passage.
Another chance for locally heavy rain may come from late Wed into
Thu with another frontal system. PW again increases close to 2
inches and deep layer SW flow could favor training of cells, but
this remains inherently uncertain 5-6 days out.
&&
.TIDES/COASTAL FLOODING...
A moderate rip current risk should continue at the ocean
beaches on Saturday via combo of 3-ft SW wind waves and 2-ft
long period SE swell. A high risk is likely for Sunday as S-SW
flow increases to 20- 25 kt and 5-ft S wind waves increase to
6-8 ft in the afternoon.
Will only mention the high risk in the SRF and HWO and hold off
on rip current statement issuance, to avoid any confusion with
the moderate risk for Saturday.
&&
.CLIMATE...
Here are current record high temperatures thru Sunday...
Saturday, June 22:
NYC: 98(1988)
LGA: 99(1988)
JFK: 94(2012)
EWR: 101(1988)
ISP: 94(2012)
BDR: 93(1949)
Sunday, June 23
NYC: 96(1888)
LGA: 95(1965)
JFK: 94(2010)
EWR: 97(1965)
ISP: 91(1999)
BDR: 91(2010)
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT Sunday for CTZ005>009.
NY...Heat Advisory until 8 PM EDT Sunday for NYZ067>075-176-178.
Heat Advisory from noon Saturday to 8 PM EDT Sunday for NYZ078-
177.
NJ...Heat Advisory until 8 PM EDT Sunday for NJZ002-004-006-103>108.
MARINE...None.
&&
$$
SYNOPSIS...BG/NV
NEAR TERM...DR/JT/NV
SHORT TERM...NV
LONG TERM...BG
AVIATION...JT
MARINE...BG/NV
HYDROLOGY...BG/NV
TIDES/COASTAL FLOODING...
CLIMATE...
Area Forecast Discussion
National Weather Service Pueblo CO
931 PM MDT Fri Jun 21 2024
.KEY MESSAGES...
- A Flash Flood Watch remains in effect until Midnight tonight
for the San Juan Mountains. More localized flash flooding
possible across the remainder of the mountains through
midnight.
- A few strong to severe thunderstorms possible over the
mountains and valleys today with hail up to 1 inch and wind
gusts up to 60 mph along with locally heavy rainfall.
- Drier and warmer pattern expected through Tuesday with
isolated mainly mountain thunderstorms and temperatures
reaching 100-105 again across the southeast plains next week.
- Another uptick in thunderstorms possible mid to late week.
&&
.UPDATE...
Issued at 929 PM MDT Fri Jun 21 2024
With decreasing forcing and instability, the threat for heavy
rainfall from thunderstorms and rain showers has lessened
substantially. Given this, the Flash Flood Watch for portions
of the San Juan Mountains has been cancelled early. Scattered
light, to at times moderate, rain showers will still be possible
through the rest of the evening.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 239 PM MDT Fri Jun 21 2024
Anomalously high moisture over the region (PWATs 200-250%+ of
normal) ahead of a shortwave trough will provide plenty of fuel for
strong to severe thunderstorms across the mountains and valleys
through this evening with heavy rainfall and flash flooding the
primary concerns. Soils are most saturated over the Eastern San
Juans were a little over an inch of rain fell yesterday afternoon
through last night. A Flash Flood Watch remains in effect for this
area until midnight. Cloud cover has hampered heating across this
area today as well as across portions of the central mountains which
has limited instability. But as cloud breaks and surface heating
occurs, odds for severe thunderstorms will increase as the afternoon
and evening continue. High res models develop a couple rounds of
convection, one which is moving through the mountains now, and
another which is associated with the stronger forcing with the upper
trough axis this evening through tonight. This latter wave may be
the one to bring the heavier rainfall to the eastern San Juan
mountains. Mean QPF from HREF suggests another inch of rain could
fall across the eastern San Juan mountains with up to 0.5 inches
elsewhere across the remainder of the mountains and valleys. 90th
percentile QPF shows up to 1.75 inches of rain across the Southwest
mountains and west slopes of the southern Sangre De Cristo range
which would be the higher side of possibilities. Stronger shear and
CAPE today will lead to one or two strong to severe storms across
the mountains as well. Storms have been and will continue to be
relatively quick moving (around 25-30 mph) but storm intensities
and antecedent soil moisture could result in flash flooding for the
more susceptible areas elsewhere across the mountains such as burn
scars, and the Chalk Cliffs. Rock slides will be possible across
the steeper terrain as well. So far rises on the gaged smaller
creeks in the eastern San Juans have remained within banks and below
action stage with additional room for rainfall. So far it still
appears that storm intensity and rainfall rates may be the primary
driver for flash flooding for these areas.
As storms move off the mountains into the adjacent plains late this
afternoon and evening, storms will become more higher based as dew
points have been mixing out into the 40s east of the mountains.
Downdraft CAPE of 1000-1300 J/kg will lead to more of a high wind
risk (gusts to around 60 mph) from the stronger cells along the I-25
corridor, however some small hail (up to an inch) could fall along
the lower eastern slopes of the southeast mountains.
Activity should diminish after midnight as the trough axis shifts
eastward and drier air works in from the north. Clouds and showers
will be latest to clear across the southern mountains.
Saturday will be drier and warmer, but there will still be
sufficient moisture for afternoon and evening showers and
thunderstorms. These will be higher based and less conducive for
producing heavy rainfall and flash flooding. However there may
still be sufficient lingering low level moisture to yield CAPE up to
1000 J/kg and deep layer shears are progged to be around 30-40kts.
So we may still have a strong storm or two over the mountains and
valleys depending on how quickly this low level moisture mixes out.
East of the mountains, thunderstorm chances fall off quickly and
these will be high based with gusty winds and lightning the primary
risks. Thunderstorms will diminish quickly with loss of heating
Saturday evening.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 239 PM MDT Fri Jun 21 2024
The heat continues to build for Sunday through Tuesday as the upper
ridge builds northward back over southern CO. H7 temperatures +18 to
+21 C will result in max temps back in the mid 90s to 105 degree
range over the southeast plains with 80s for the valleys and 60s and
70s for the higher mountains/mountain communities. Monday and
Tuesday could see more Head Advisories for portions of the I-25
corridor and southeast plains depending on these details, and this
risk will be monitored closely. Fortunately, winds look relatively
light which should mitigate any critical fire weather potential even
though relative humidity values will be quite low in the afternoons.
There will still be enough mid/high level moisture present for
isolated high based thunderstorms each day, mainly across the
mountains. Gusty winds and lightning with little to no rainfall
would be the primary risks.
Upper high picks up some subtropical moisture Wednesday into the
latter part of next week which will bring increasing moisture and
better chances for thunderstorms to the region especially Thursday
into Friday as moisture quality increases. This will take the edge
off temperatures some, but temperatures will still remain hot with
highs 5-10 degrees above normal. Models advertise another upper
trough for next weekend which shunt the moisture plume to the east
and south once again so any uptick in thunderstorms late week
appears temporary. -KT
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 513 PM MDT Fri Jun 21 2024
At KPUB and KCOS, HRRR consistent in bringing a wave of
weakening tsra into the I-25 corridor 02z-04z, so will keep a
vcts mention both sites this evening, with precip gradually
ending after 04z. For the remainder of the night and into
Saturday, expect VFR conditions, as most convection stays west
of both terminals over the higher terrain.
At KALS, vcts this evening, with potential for brief MVFR/IFR
vis under heavier cells from 00z-03z. Lingering -shra and
periods of MVFR cigs possible until 06z, before precip fades
away early Sat morning. VFR then expected during the day Sat,
with vcts after 21z as mountain convection again drifts
eastward across the San Luis Valley
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...SIMCOE
SHORT TERM...KT
LONG TERM...KT
AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service San Diego CA
855 PM PDT Fri Jun 21 2024
.SYNOPSIS...
Hot conditions expected through the weekend for the valleys,
mountains, and deserts and in the deserts next week. A surge of mid-
level moisture will bring higher humidity and a slight chance for
showers and thunderstorms from the coast to the deserts late
Saturday night into Sunday, locally in the San Bernardino mountains
on Monday afternoon. A shallow marine layer will keep coastal highs
in the 70s and 80s.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.Evening Update...
Warmer weather occurred inland today compared to yesterday. Highs
reached into the low to mid 90s across the Inland Empire and over
110 degrees in the lower deserts, while beautiful beach weather
was had with highs in the 70s. GOES imagery shows low clouds
slowly reforming near the San Diego Co coastline this evening.
The marine layer will be slightly shallower tonight than this
morning, keeping low clouds within around 15 miles of the beaches.
Probabilities for temperatures over 100 degrees are highest
tomorrow across the eastern and southern portions of the Inland
Empire and much of the high desert, with guaranteed highs at or
above 110 degrees again across the lower deserts.
Please be mindful if venturing outdoors for recreation this
weekend as most areas will be quite warm. Even in the mountains,
highs will be in the upper 80s to mid 90s from Julian to
Idyllwild. Remember to take frequent breaks and drink plenty of
fluids if outdoors.
Latest hi-res guidance shows minimal activity for the region
Saturday. Moisture will increase by Saturday night into Sunday.
A small chance for storms exists in most areas our coverage area
with the HRRR showing the greatest chance for storms along the
mountain spine into some adjacent valleys west of the mountains.
Forecast looks reasonable for now, but we will continue to assess
as the event gets closer.
.Previous Discussion (216 PM Friday)...
A ridge of high pressure currently over Texas, will drift west
towards the Southwest United States this weekend. That ridge of high
pressure will remain over the Four Corners region through most of
next week. The ridge will result in hot conditions across Southern
California and allow for an increase in mid-level moisture Sunday,
with some moisture lingering into Monday. Widespread moderate to
major heat risk away from the coast is expected on Saturday.
Temperatures will get knocked down a few degrees on Sunday for
inland areas due to an increase in moisture. Even with temperature
readings a few degrees lower than Saturday, hot and muggy conditions
are expected with highs 5 to 10 degrees above average.
Temperatures for locations in and west of the mountains will peak on
Saturday, gradually decreasing into next week. Widespread moderate
heat risk will continue into Sunday in and west of the mountains,
with heat risk becoming locally moderate for the eastern portions of
the valleys by Monday. High temperatures in the deserts will fall a
few degrees on Sunday, before increasing again for Monday.
Conditions in the deserts will remain hot enough for moderate to
major heat risk through Thursday. For the end of next week, a trough
of low pressure will approach the Pacific Northwest, weakening the
ridge and pushing it off to the south and east. This will allow
temperatures to fall to within a few degrees of the seasonal normals.
For Sunday, a surge of mid-level moisture will bring higher humidity
to the area. The increased humidity will make it harder to keep cool
during outdoor activities even with high temperatures a few degrees
cooler than Saturday. Model guidance continues to show an easterly
wave in the southeast flow around the Four Corners making its way
across Southern California Sunday. This shortwave interacting
with the mid-level moisture will destabilize the atmosphere
sufficiently for showers and thunderstorms Saturday night and
Sunday from the coast to the deserts. The increase in Most
Unstable CAPE in the mid-levels of the atmosphere over the
coastal waters and near the coast is indicating the potential for
elevated convection which could bring thunder and lightning with
little to no rainfall accumulation. Measurable precipitation
(25-35%) and thunderstorms (15-20%) are most likely over the
mountains, with lesser chances of measurable precipitation
(15-20%)and thunderstorms (5-10%) for the coast, valleys, and
deserts. Isolated thunderstorm chances will linger Monday
afternoon in the San Bernardino Mountains (20%).
&&
.AVIATION...
220345Z...Coast/Valleys...Satellite depicts slow and patching return
of marine clouds. This is expected to continue patchy tonight and
late. A shallower marine layer brings the threat for MVFR in fog
and IFR ceilings at CRQ and 30 percent chance of ceiling below
1000 FT AGL at SAN for 10 to 14z. Early burn off between 15 and 16Z
on Saturday.
Mountains/Deserts...
Clear and lighter winds than recently. Light diurnal winds on Saturday
but very hot again. Late after winds of 20 kt in the passes.
&&
.MARINE...Tropical moisture is expected to arrive Saturday night
through Sunday morning. Meanwhile patchy low clouds. The moisture
is enough with a weak disturbance to bring a threat for widely
scattered lightning and brief showers Saturday night and Sunday morning.
Marine weather statement continues for this weather.
&&
.BEACHES...
There is a slight chance of a thunderstorm Saturday night through
Sunday morning which could produce cloud-to-ground/cloud-to-water lightning
strikes. Chances of a lightning strike near any particular beach are
currently 10-20 percent or less Saturday night and Sunday. Rain showers will
generally be light to moderate and brief.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 10 AM Saturday to 8 PM PDT Sunday for Orange
County Inland Areas-San Bernardino and Riverside County
Valleys-The Inland Empire-San Diego County Valleys.
Heat Advisory from 10 AM to 8 PM PDT Saturday for Riverside
County Mountains-San Bernardino County Mountains-San Diego
County Mountains.
Excessive Heat Warning from 10 AM Saturday to 8 PM PDT Thursday
for Apple and Lucerne Valleys-Coachella Valley-San Diego
County Deserts-San Gorgonio Pass Near Banning.
PZ...None.
&&
$$
PUBLIC...APR/CO
AVIATION/MARINE...Tardy
Area Forecast Discussion
National Weather Service Tucson AZ
128 PM MST Fri Jun 21 2024
.SYNOPSIS...A strong increase in moisture will bring daily chances of
thunderstorms to the area into next week. Some storms will
generate strong outflow winds with locally heavy rain possible.
This will also knock several degrees off of the heat. We may see
temperatures climb back up a bit as high pressure settles
overhead next week.
&&
.DISCUSSION...Partly to mostly cloudy skies early this afternoon
across southeast Arizona with considerable mid and high level
cloudiness. We`re now seeing cumulus clouds developing due to the
heating, moisture and instability across the region as PWAT values
range from 1 to 1.5 inches across the area. Gusty east to southeast
winds continue this afternoon but wind speeds have certainly
diminished compared to yesterday and earlier this morning. HREF/CAMs
are showing convective development this afternoon primarily in a
north-south zone across central portions of the forecast area. The
center of this line would be from around Nogales-Tucson-Kearny.
MLCAPE values are locally in the 1000-1500 J/KG range this afternoon
per the latest RAP mesoanalysis with DCAPE values near 2000 J/KG.
This will result in strong/gusty outflow winds from the thunderstorm
activity that does develop. In addition, some locally heavy rainfall
of around 0.5"-1" is expected with the stronger storms. The
convection will make it a bit farther west today compared to
yesterday as greater moisture levels allow additional westward
development on outflow boundaries. In addition, some areas of
blowing dust may occur primarily in Pinal County due to gusty
outflow winds. A few of the CAMs are persisting shower activity into
the overnight but stronger thunderstorms will mainly occur through
the afternoon into early evening.
Additional moisture will move into the area tonight and Saturday
from Sonora and the Gulf of California. This will raise the PWAT
values this weekend into the 1.25" (eastern areas) to around 2"
(western deserts). These are very anomalous for late June, running
about 3 to 4 standard deviations above normal. With abundant
moisture and the mid/upper level high to our east, our region will
continue to see a favorable steering flow from the southeast. That
combination of deep moisture, favorable steering and instability
will result in scattered mainly afternoon and evening showers and
thunderstorms this weekend for the entire forecast area. The
stronger storms will have both wind and localized flooding threats,
as rain amounts in excess of 1 inch are possible with the stronger
storms. Temperatures will drop back down to seasonable levels this
weekend.
For Monday and continuing through next week, the mid/upper level
high will gradually strengthen and shift a bit closer to southeast
Arizona. Therefore, while the moisture isn`t going anywhere and will
be recycled each day, the mid/upper level high location and
potential subsidence will tend to shift the focus of convective
activity a bit closer to the higher terrain overall with the better
chances starting to focus a slightly more towards areas from Tucson
south and eastward. Temperatures will nudge back up next week,
running a few degrees above normal.
&&
.AVIATION...Valid through 23/00Z.
SCT-BKN clouds 10-14k ft AGL. SCT -TSRA will with TSRA and BKN CIGS
around 6k ft AGL possible thru 22/03Z. Sct -SHRA then possible
overnight but confidence is low. East to southeast winds 10-20 kts,
diminishing after 22/03Z. Stronger and erratic outflows possible
with storms. Additional SCT -TSRA activity expected aft 22/18Z thru
the end of the period. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Gusty east to southeast winds continue to diminish
this afternoon. A strong increase in moisture will bring better RH
values along with a chance of thunderstorms into at least early next
week. Some storms will generate strong and erratic outflow winds.
Moisture is expected to be deep enough for some storms to generate
locally heavy rain.
Temperatures may heat back up by mid week as high pressure builds
nearly overhead, however we should keep some storm chances around.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
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