Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/26/17
Area Forecast Discussion
National Weather Service Albany NY
1014 PM EDT Sun Jun 25 2017
.SYNOPSIS...
An upper level disturbance will move across the region through
this evening triggering scattered showers and isolated
thunderstorms. Another cold front and upper level disturbance
will trigger scattered showers and isolated thunderstorms again
Monday and Tuesday mainly during the afternoon and evening hours.
Temperatures will average below normal through the start of the
new week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 1000 PM EDT, second line of showers associated with a
shortwave trough continues to push through eastern NY into
western New England late this evening, but all lightning has
dissipated. These showers will likely continue for the next few
hours as the shortwave continues to push east. Temperatures have
also cooled off quickly behind the showers so have adjusted the
hourly temps. Also freshened up the sky cover and sent updates
to NDFD and web servers.
Prev Disc...
Mesoscale Update...Two lines of convection continue to track
across Upstate NY this early evening. The initial line appears
to be along an outflow boundary as the second, near the I81
corridor, was along the leading edge of the upper vortmax and
associated trough axis. SBCAPES per LAPS were still holding
between 200-500 J/KG, however, the lapse rates were increasing
as the cold pool was approaching. HRRR suggests this upstream
activity should hold together with a slow diminishing trend as
it transverses the region through the evening hours. So we
updated the PoPs to hold on a little longer but did drop thunder
potential after 02Z. Otherwise, did tweak the sky coverage per
the experimental 1-min GOES-16 satellite imagery.
Prev Disc...
H2O vapor loop nicely depicts short wave rotating
ENE across the eastern Great Lakes. Main mid and upper level jet
was right across the region as we are not in either favored
enhanced dynamical regions. While surface temperatures where
generally into the 70s with some lower 80s in the mid Hudson
Valley region, this has resulted in SBCAPES between 300-500 J/KG
as lapse rates was near 7C/KM per LAPS across the DACKS to near
5.5 C/KM for the mid Hudson Valley and NW CT. Per the HRRR,
seems best coverage would be across the terrain and the DACKS
which will continue into the evening hours before dissipating
tonight. Then a partly cloudy to mostly clear skies overnight as
lows dip back mainly into the 50s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Forecast really has not changed too much as yet another short
wave will move out of central Canada and deepen the longwave
trough over the Great Lakes region Monday. The trough will
sharpen with the trough axis expected to move across the region
Tuesday into Tuesday night. Heights will fall and the cold pool
associated with the short wave will moderate some but pass over
the area Tuesday. However, best jet support seems to be a little
further east per the 12Z NCEP Model Suite. Again, expect
scattered showers with isolated to widely scattered
thunderstorms both Monday and Tuesday mainly during the
afternoon and evening utilizing daytime heating. The better
chances will be Tuesday as the trough axis moves over the
region. Deeper convective elements will have the potential to
produce some hail and gusts winds from time to time as lapse
rates steepen a bit more on Tuesday as sub -20C @ H500 moves
overhead.
Below normal temperatures both Monday and Tuesday by 5 to 10
degrees with highs from the upper 50s/lower 60s across portions
of the western Adirondacks into the mid/upper 70s in the mid
Hudson Valley into northwestern Connecticut.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
The shortwave trough from Tuesday will be slowly exiting heading
into Wednesday with the trough axis likely east of our CWA by
Wednesday morning. However, guidance continues to suggest an
embedded shortwave sliding into the Adirondack/northern CWA
Wednesday giving a returned threat for POPs. Daytime heating should
yield some instability with the 12 km NAM and GFS both showing a
bullseye of 1000 - 1800 J/kg of SFC CAPE developing by 18z in the
Lake George/Saratoga region. Thus, slide highest POPS into that
region for the afternoon. Further south, high pressure moves into
the mid - Atlantic by the afternoon with its northern periphery
providing subsidence and thus a dry forecast for the southern half
of the CWA. Temperatures still a bit below normal with highs in the
70s.
The pattern turn more active Thursday into the weekend with
consecutive days of precipitation threats and increasingly warm and
humid temperatures. A warm front noses into our region Thursday from
southern Canada and brings with it impressive WWA with guidance
showing lots of packing of H850 isotherms and H850 winds becoming
parallel to the isotherms. Thus, have likely POPS in the northern
CWA for the entire day with increasing POPS for the southern half.
Exactly how far north the warm front travels is still uncertain. The
atmospheric flow becomes zonal over northern New England/southern
Canada suggesting the low could very well travel from Quebec across
northern NY/central VT before heading out to the Atlantic. It`s
worth to note that the front should not stall for an extended period
of time as 700mb winds are fast ranging 40 - 50 knots.
Continued chance POPS for Friday - Saturday as the system`s
associated cold front could move eastward through our CWA but may
actually stall and lift back north again as warm front. As expected,
exact timing is uncertain. However, PWAT values look to increase for
the weekend due to southwesterly atmospheric flow around off shore
high pressure, potentially reaching 1.5 - 2 inches. Thus, any
convection could produce downpours. Temperatures also rise back
above normal into the mid - upper 80s with dew points rising well
into the 60s.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Outside of any scattered showers and storms this evening, VFR
conditions with scattered variable broken clouds at 5000 feet or
higher expected tonight. There could be some patchy fog at
KGFL, KPSF and KPOU between 09Z-13Z so indicating BCFG at this
time. Will have to analyze and monitor conditions overnight to
see if more mention of morning fog is needed.
After 13Z, VFR conditions at all TAF sites with scattered clouds at
or above 5000 feet trending to a broken ceiling. Visibilities will
also remain VFR. Chance for convection increases once again
toward noon as we will include a VCSH at this time.
West to southwest winds this evening at around 10 Kt, with a
few gusts possible near showers. Winds diminish to 6 Kt or less
overnight and hold from the southwest to west at less than 10
Kt Monday morning.
Outlook...
Monday Night: Moderate Operational Impact. Scattered SHRA...TSRA.
Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Tuesday Night: Low Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Friday: Moderate Operational Impact. Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
Some scattered showers and isolated thunderstorms mainly during
the afternoon and evening hours. Another cold front and upper
level disturbance will trigger scattered showers and isolated
thunderstorms again Monday and Tuesday mainly during the
afternoon and evening. Seasonably warm today with cooler, below
normal temperatures Monday and Tuesday.
&&
.HYDROLOGY...
Hydrological problems are not anticipated through over the next
several days. Scattered showers and isolated thunderstorms are
expected through early this week, mainly during the afternoon
and evening hours, as short wave troughs and cold fronts
approach and move across the region.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...IAA/BGM
NEAR TERM...IAA/BGM/NAS/JVM
SHORT TERM...IAA/BGM
LONG TERM...Speciale
AVIATION...BGM/NAS
FIRE WEATHER...IAA/BGM
HYDROLOGY...IAA/BGM
Area Forecast Discussion
National Weather Service Denver/Boulder CO
817 PM MDT Sun Jun 25 2017
.UPDATE...
Issued at 805 PM MDT Sun Jun 25 2017
No tstms over the cwa at this time. Ely low lvl flow has
developed fm Denver south to the Palmer Divide with
some agitated cumulus. Thus will keep in low pops
over the Palmer Divide into Park County thru midnight
in case an isold storm or two develops after sunset.
&&
.SHORT TERM...(This evening through Monday)
Issued at 325 PM MDT Sun Jun 25 2017
Northwesterly flow aloft continues as an upper ridge is over the
desert southwest and a broad trough is over the Great Lakes area.
High surface pressure over the Great Plains keeps cool and moist
air over the plains. Low stratus covered for the forecast area for
longer than expected keeping a cap over most of the area except
south over the Palmer Divide, where cells have formed and tracked
southeast. The HRRR model did quite well today with the convective
forecast - better than the last couple of days. Some hint that
some convection will occur this evening and push slightly
northward into the metro areas. Shouldn`t be very strong or last
very long with the upper ridge continuing to push in and the loss
of the suns heat.
The upper ridge axis will push into the state Monday for warmer
and drier conditions area wide as the surface upslope flow will
weaken. Isolated showers/weak storms are still possible mainly
over the higher terrain south of I70, and perhaps over the far
eastern plains where CAPE is progged to be in the 1500-2000 J/kg
and marginal shear.
.LONG TERM...(Monday night through Sunday)
Issued at 325 PM MDT Sun Jun 25 2017
The ridge axis will shift east across Colorado Monday night and
Tuesday as an embedded wave in the flow moves over the area late
Tuesday. Expect a few more thunderstorms will move over the
plains during this time period with even the potential for a few
severe storms over the plains with better low level moisture.
Temperatures will also be warmer on Tuesday as the thermal ridge
will be over Eastern Colorado with readings well into the 90s.
Following the trof on Tuesday evening the flow will increase from
the west and northwest through the end of the week. This will open
Colorado to more weak fronts for Thursday and Friday with a
cooling trend and a bit better chance for storms. However, overall
storm coverage looks to be on the lower side.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 805 PM MDT Sun Jun 25 2017
Ely winds have developed with some lower ceilings between
3500 and 4000 ft. Winds are fcst to become more sely
before 06z and then sly by 09z. Lower ceilings should
break up in the next hour or two.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...RPK
SHORT TERM...Kriederman
LONG TERM...Entrekin
AVIATION...RPK
Area Forecast Discussion
National Weather Service Taunton MA
1000 PM EDT Sun Jun 25 2017
.SYNOPSIS...
Scattered showers and isolated thunderstorms will diminish by
midnight. Additional upper level disturbances move across New
England on Monday and Tuesday, bringing a few showers or
isolated thunderstorm. Then a warming trend begins for the
latter half of the week with a return to summer heat and
humidity by Friday. A warm front may bring some showers Thursday
with more showers and thunderstorms possible Friday and
Saturday. A backdoor front may drop south into the region
Saturday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
10 PM update...
Area of showers and isold t-storms moving through MA have
developed in the right entrance region of the upper jet. Wind
gusts to 30-40 kt have been reported. More showers are
developing in eastern NY and HRRR indicates these will hold
together as they move across the MA Pike region next few hours.
Updated PoPs to reflect current trends and hi-res guidance.
Previous discussion...
Lingering instability along with the right entrance region of
the upper jet...this may support a few showers/tstms through the
first hours of the night. Upper shortwave moving along the
Canadian border moves off to the northeast tonight. The
instability will diminish and the upper jet will shift southeast
during the night, so expect any showers to end and skies clear.
Clearing skies and light wind will allow some radiational
cooling. With dew points in the 50s, expect min temps mainly in
the 50s...except low 60s in some urban centers.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Upper flow remains cyclonic. A weak shortwave moves through the
flow and across New England on Monday. Temps aloft will be a
couple of degrees cooler, with solar heating working on the
surface temperatures. The resulting lapse rates should be
favorable for a few showers/tstms.
Mixing will again reach high, up to 800 mb or a little higher.
Temps at that level, equivalent to 11C at 850 mb, will support
max temps in the upper 70s and the low 80s.
Convection will again diminish after sunset with clearing skies
and light wind. With dew points in the 50s, expect min temps in
the 50s and low 60s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Highlights...
* A few showers/isold t-storm possible Tue/Wed
* Warming trend toward end of the week with return to summer
heat/humidity by Fri
* Thunderstorm chances increase Thursday night through Saturday
* Low confidence - Backdoor front possible far northeast MA Sat.
Overview...
Mid level trough exits New England Wed., followed by building
heights as subtropical ridge builds over the western Atlantic.
Polar jet will be in the vicinity of New Eng next weekend which
will leave us susceptible to weak shortwave passages. A warm
front will meander back and forth near the MA/NH border Friday
through Sunday with a series of weak low pressure systems moving
along the boundary. Thus the chance of showers and
thunderstorms will increase as we head into the weekend.
Details...
Tuesday and Wednesday...
Strong mid-level shortwave trough lifts northeast from the Great
Lakes Tue with axis of the trough moving into New England by
Tue. evening before exiting on Wed. With 500 mb temps cooling
to -18 to -20C, will see scattered showers and isolated
thunderstorms. The best chances, where K Indices reach 25-30
along with Total Totals greater than 50, will be in the
northwest half of the region, west of a line from northern CT to
the Merrimack Valley.
For the second run in a row, the ECWMF shows a surface trough
south of New England, which creates an area of rain showers for
south coastal RI and southeast MA Tue. night into early Wed.
morning. Will forecast a chance of showers there.
On Wed, mid level trough exits the region. There will still be a
cold pool aloft, hence Total Totals Indices in the lower 50s.
However, the column will be drying out with westerly winds and
K Indices struggling to surpass 20-25. Cannot rule out a slight
chance of a few showers. But not expecting thunder.
Highs both Tue. and Wed. from 77 to 80 in the interior.
Thursday...
Increasing warm advection pattern as warm front approaches from
the SW will lead to increasing clouds. Southwesterly low level
jet is forecast to increase to 40-50 kt at 850 mb by late in the
day. Despite some cloud cover temperatures will rise to the mid
80s and this will allow for mixing to create wind gusts to 20-30
mph, especially in the coastal plain.
GFS and ECMWF now in agreement that the warm front will move to
near the MA/NH/VT border by Thu. evening. There is a pronounced
increase in K Indices as high theta-e air moves in from the
west. The implication is that a cluster of thunderstorms,
possibly severe to our west, will travel eastward along the warm
front, aided by swift 55-70 kt west winds at 500 mb. There is a
good chance of thunderstorms in northern and western MA late
Thu. afternoon and Thu. night as a result, with scattered
storms possible elsewhere Thu. night.
Friday and Saturday...
Somewhat tricky forecast due to placement of active frontal
boundary. Very unstable air mass in place both Fri. and Sat.
High temperatures will reach well into the 80s with near 90
possible. Dewpoint temperatures are forecast to hover between
the upper 60s and lower 70s. The frontal boundary is forecast to
become quasi- stationary near the MA/VT/NH border by
Saturday...and it may even shift southward a tad as a backdoor
cold front into the Cape Ann region on Saturday.
Several thousand Joules of CAPE are possible on either day.
Scattered thunderstorms are expected both days and there is the
potential for severe weather, with wet microbursts a possibility.
Helicity values could be higher near the MA/NH/VT border, close
to the front, which may add to severe potential.
Sunday...
Tricky forecast continues...with models suggesting a slow moving
surface trough and a continued chance of scattered showers and
thunderstorms. Highs mainly in the mid 80s due to cloud cover,
but subject to change...could be higher if more sunshine.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Monday Night/...High confidence.
654 PM update...
Tonight...
VFR. Scattered showers and isolated thunderstorms will progress
eastward across portions of southern New England tonight,
exiting the coast around 04-05Z. Brief MVFR vsbys in any
showers. Clearing skies overnight with light winds.
Monday into Monday night...
VFR. Daytime heating will develop cumulus clouds with bases
4000-5000 feet. These will lead to scattered showers and a few
thunderstorms. Brief vsbys below 5 miles in any showers.
Clouds and showers dissipate after sunset.
KBOS Terminal...High confidence in TAF.
KBDL Terminal...High confidence in TAF.
Outlook /Tuesday through Friday/...
Tuesday and Wednesday...High confidence.
Mainly VFR. A few showers and isold t-storms possible Tue and
still can`t rule out a shower on Wed.
Thursday...Moderate confidence.
Mainly VFR with cigs lowering from NW to SE. Afternoon showers
possible in the interior with showers/t-storms possible all SNE Thu
night. Gusty SW winds to 25-30 kt developing, especially
coastal plain.
Friday...Moderate confidence.
Patchy early morning fog, with local MVFR. Then VFR, except
local IFR in possible strong thunderstorms, mainly during the
afternoon and evening hours. MVFR in patchy fog late Friday
night, especially south coast.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Monday Night/...High confidence.
High pressure offshore with west to southwest winds. Speeds
should remain 20 knots or less. Seas have diminished, and should
remain at 4 feet or less through the period.
Outlook /Tuesday through Friday/...
Tuesday and Wednesday...High confidence. Quiet boating weather with
winds and seas below SCA. Gusts to 20 kt possible nearshore waters.
Thursday...Moderate confidence. Small craft advisories will
likely be needed. Increasing SW winds with gusts to 25+ kt
likely, especially over nearshore waters. Building seas may
reach 6 to 8 ft over southern waters Thu night. Chance of
showers and thunderstorms Thursday night.
Friday...Moderate confidence. SW winds continue, mainly 20-25 kt
with seas 4-8 ft over the southern waters and 3 to 6 ft over the
eastern waters. Scattered thunderstorms, some with reduced
visibilities and strong gusty winds.
&&
.TIDES/COASTAL FLOODING...
High astronomical tides have peaked at most spots, but still at
high levels for at least one more cycle. The overnight tide
cycle will be the one of concern, with Boston reaching 12.2 feet
after midnight tonight. Tidal departures will be around 0.3 to
0.4 feet along the Massachusetts East Coast. This means
conditions will be high enough along the Mass East coast for at
least some minor splashover at high tide.
Subsequent high tides will be trending lower, and thus less of a
risk for splashover concerns.
&&
.EQUIPMENT...
KBOX radar is down. Technicians have been notified and will be
looking into the problem.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...WTB/GAF
NEAR TERM...WTB/KJC
SHORT TERM...WTB
LONG TERM...GAF
AVIATION...WTB/GAF
MARINE...WTB/GAF
TIDES/COASTAL FLOODING...
EQUIPMENT...
Area Forecast Discussion
National Weather Service Columbia SC
1028 PM EDT Sun Jun 25 2017
.SYNOPSIS...
A slow moving cold front will stall along the coast tonight
while high pressure builds in from the northwest. Cooler and
drier air with lower humidity is expected through mid week.
Moisture will return by the end of the week with increasing
temperatures and chances of rain through the weekend.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
UPDATE: Showers developing along an outflow boundary over the
central Midlands from Bishopville through Rembert to just south
of Columbia to Gaston. MesoAnalysis indicated moisture
convergence with CAPES 2000-3000 J/kg and LI minus 3C to minus
5C. HRRR model has this area of convection drifting slowly
southeast through 06Z. Have adjusted pops across the Midlands
accordingly.
Previous Discussion: An upper level trough will continue over
the eastern CONUS. An upper level disturbance moving through the
base of the trough combined with slow moving frontal boundary
will continue showers and thunderstorms from the eastern
Midlands to the coast early this evening. The front will move to
the coast by daybreak Monday.
Convection should gradually move east of the Midlands during the
evening as drier air continues to filter into the region from
the north. Dewpoints will lower to lower 60s by Monday morning.
Patchy fog will be possible from the southern Midlands to the
CSRA tonight. Have forecasted overnight lows from the mid 60s
north and west to the lower 70s southeast.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
The surface frontal boundary will be stalled along the coastal
plain on Monday with weak north to northwesterly flow across the
forecast area. The deeper moisture will still be lingering over
the southeastern Midlands and lower CSRA with precipitable
water values around 1.5 inches through the morning but lowering
through the day as high pressure continues to build into the
area. Forecast instability is expected to be minimal with lifted
index values around -2C through early afternoon and diminishing
after that with daytime mixing.
Given the very weak instability and diminishing deep moisture during
peak heating and frontal boundary southeast of the forecast area,
will carry a dry forecast although cannot rule out an isolated
shower in the far eastern Midlands. Temperatures will be slightly
below normal with highs in the mid to upper 80s and lows Monday
night in the lower to mid 60s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A digging upper trough will move across the Ohio Valley and Mid-
Atlantic on Tuesday bringing colder 500mb temps around -12C to the
region. The deeper moisture and surface boundary that pushed
through the forecast area will remain stalled along the coast with
precipitable water values over the forecast area generally in the 1
to 1.3 inch range with the higher values in the southeastern
Midlands. The limited moisture is a limiting factor for convection
and forecast instability is expected to remain weak in our area so
will continue to carry slight chance pops mainly east of I-77 and
south of I-20 corridors.
Another shot of drier air will filter into the area behind the
trough Tuesday night and settle over the area Wed/Thu with surface
high pressure becoming centered over the Carolinas. This seasonably
cooler and drier air mass will provide stable conditions and prevent
diurnal convection while providing a more comfortable less humid
environment for outdoor activities.
Moisture will be on the increase Friday through the weekend as the
surface ridge shifts offshore and return southerly flow develops.
The upper level pattern Fri-Sun becomes more zonal at 500mb with
some weak troughiness moving into the area Sat/Sun which will
provide an increased chance of diurnal convection supported by
precipitable water values back close to 2 inches.
Temperatures through this period will be slightly below normal
Tuesday then near normal the remainder of the week into weekend.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Area of dissipating convection near OGB in then ear term.
Otherwise, drier air will push into the FA from the north late
tonight behind a secondary front/trough. Veil of mid and high
level cloudiness appears will continue streaming across the FA,
though it may push south of the FA late tonight/early Monday
morning. These factors appear to preclude fog/stratus concerns
over most of the FA. However, at fog prone OGB where
precipitation occurred this evening and where dewpoints are
higher, some possibilities of fog/stratus exist, with some
potential at fog prone AGS if cloudiness clears late tonight.
Will include tempo groups at both locations. Otherwise, VFR.
Drier air will continue pushing into the FA Monday under NE
surface winds.
EXTENDED AVIATION OUTLOOK...No significant impacts to aviation
expected.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Caribou ME
922 PM EDT Sun Jun 25 2017
.SYNOPSIS...
A trough of low pressure will remain to our west this week.
Occasional disturbances tracking out of this trough and across our
area will bring periodic chances for showers and thunderstorms.
&&
.NEAR TERM /THROUGH MONDAY/...
9:22 PM Update...Showers with embedded thunderstorms extend
from northern Penobscot County southeast to northern Washington
County as of 9 PM. The showers will continue to track to the
northeast, and most of this activity should move out of eastern
Maine by midnight. A cold front in Quebec will move into
northwest Maine around or a little after daybreak with some more
showers. The main updates at this time were the the PoP and
weather grids based on the latest radar and near term model
trends.
Previous discussion...
Some showers have been popping up this afternoon across
northern and western areas as upper jet streak has been
enhancing these showers. Satl wv imagery coupled w/the lightning
display showed a disturbance move ene w/some lightning activity
across southern Quebec and NH. This activity will lift ene into
the evening. The latest meso-analysis showed the best
instability into the n and w but this looks to change by later
in the afternoon into the evening. RAP soundings showed CAPES
hitting 400-500 joules across central and western areas w/steep
lapse rates and 0-6km shear of 25 kts. Decided to keep enhanced
wording(winds/hail) into the evening w/the stronger cells.
Activity will wind down across the central and downeast areas
later in the evening. More showers and perhaps a tstm for the
northern 1/2 of the CWA later on as a cold front residing back
across Quebec apchs the region overnight. The best forcing
appears to be across northern Aroostook County. Temps will cool
down behind the front across far northern and western areas as
the front moves across that region Monday morning w/upper 40s to
around 50. The rest of the CWA will be in the 50s.
The front is expected to slide into eastern areas by mid morning
Monday w/showers across the eastern areas. The front is forecast
to slide further s during the day on Monday as shown by the NAM
GFS and Canadian GEM and weaken. Some weak forcing was noted
especially by the GFS to keep some showers going into Monday
afternoon across the downeast areas. Decided on 20-30% pops
using a blend of the guidance. Rainfall for this term will be
0.10 inch or less except w/any tstms.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
An upper level trough and weak surface low will be centered to our
west, just north of the Great Lakes Monday evening. The trough will
remain to our west through the middle of next week bringing
occasional chances for showers. A weak disturbance running out of
the trough and across our area late Monday night into Tuesday will
bring a good chance for showers and some thunderstorms. The most
likely focus of the showers will be along a weak surface frontal
boundary across the north central part of our area on Tuesday.
Showers would likely diminish Tuesday night. However, another
similar disturbance kicking out of the Great Lakes trough will come
along on Wednesday and bring a renewed chance for showers and
thunderstorms. Central and northern areas look favored again.
Forecast capes both Tuesday and Wednesday look similar, around 500
J/KG across the north and a little less Downeast.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The weather disturbance crossing the area on Wednesday will lift
away Wednesday night as a small high builds in behind it. The
mid- week period will then feature a big, warm and humid high
pressure system off the southeast coast and big, cool and dry
high pressure system over Hudson bay. A well defined frontal
boundary in the trough over the Great Lakes will divide the two
and provide focus for convergence. Moisture converging in this
front will stream east into our area on Thursday ahead of a
large surface low squeezed between the two highs. This will
bring a chance for some rain late Thursday into Friday. The
boundary may push south late Friday into Saturday before the
main body of the surface low lifts north, to our west, late
Saturday into Sunday. This has the potential to carry a lot of
moisture north along the boundary bringing a chance for a
soaking rain over the weekend.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR for all terminals into Monday outside of any
convection with briefly lower ceilings and visibilities. Across
some of the northern terminals from KHUL to KFVE as cigs could
hit MVFR for a brief time Monday morning w/the arrival of the
cold front.
SHORT TERM: VFR conditions Monday evening may drop to MVFR
Monday night into Tuesday, especially across the north, but
range between VFR and MVFR Downeast. Conditions should improve
to VFR Tuesday night into early Wednesday then drop back to MVFR
Wednesday night in lower clouds and showers.
&&
.MARINE...
NEAR TERM: The wind and seas are expected to remain below small
craft advisory levels through Monday.
SHORT TERM: Winds and seas are expected to be below SCA Monday
night through Thursday. Fog may limit visibility across the
waters at times.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...CB/Hewitt
Short Term...Bloomer
Long Term...Bloomer
Aviation...CB/Hewitt/Bloomer
Marine...CB/Hewitt/Bloomer
Area Forecast Discussion
National Weather Service Dodge City KS
605 PM CDT Sun Jun 25 2017
...UPDATE TO AVIATION...
.SHORT TERM...(This evening through Monday)
Issued at 315 PM CDT Sun Jun 25 2017
Broad high pressure again was positioned from the northern plains
through the southern plains this afternoon. There was a
thermal/moisture gradient around 850 mb over northwest Kansas where
thunderstorms this morning slowly advanced southeast into the west
central counties. The HRRR and other convective allowing models
depict the heavier activity to become much less organized and
smaller in areal coverage in the coming hours as it continues
southeast into south central Kansas.
The rain cooled air behind this activity, already in the 50s will
lead to even cooler temperatures for much of the area heading into
the evening, mainly over the northern counties.
Temperatures tonight may be modified heavily by the next few runs of
the Hi-res rapid refresh model. Low clouds/stratus that was already
being developed in the far southwest by the RAP13km/HRRR and HiRes
NMM may be more widespread overnight as well following the rains
across the area this afternoon.
Models show the the low clouds slow to break up early Monday. The
same conditionally unstable atmosphere will still be in place with
the return of weak to moderate surface based CAPE. There does not
appear to be much of a forcing mechanism for lift until the evening
hours when a front slides south into central Kansas.
.LONG TERM...(Monday night through Sunday)
Issued at 315 PM CDT Sun Jun 25 2017
The cool period of the weekend and early part of the workweek will
come to an end as a broad upper ridge followed by zonal upper flow
and southwest downslope boundary layer air. Shortwave Tuesday night
may or may not mean thunderstorms for southwest Kansas as there are
differences in the GFS and ECMWF at this point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 600 PM CDT Sun Jun 25 2017
Widely scattered showers and a few embedded thunderstorms will
move southeastward across central and southern portions of
southwest Kansas through late this evening, likely affecting KHYS.
Otherwise, VFR conditions will prevail at all TAF sites through
early Monday morning. Low level stratus is expected to develop
toward daybreak Monday morning near and along a quasi-stationary
frontal boundary stretching from western Oklahoma across the
panhandles of Texas and Oklahoma. MVFR cigs will be possible in
the vicnity of KGCK, KLBL, and potentially KDDC early to mid
Monday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 58 82 62 89 / 30 20 30 10
GCK 55 84 61 90 / 30 20 30 10
EHA 58 83 62 90 / 50 20 20 10
LBL 60 83 63 91 / 30 20 20 10
HYS 55 81 61 88 / 30 20 20 10
P28 60 85 64 89 / 20 20 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1026 PM EDT Sun Jun 25 2017
.SYNOPSIS...
Dry and cool air will continue to spread in from the northwest over
the forecast area through much of the week as Canadian high pressure
remains to our north. As the high moves offshore, moist southerly
flow will return toward the end of the week through the weekend.
&&
.NEAR TERM /THROUGH MONDAY/...
1020 PM update: Adjusted overnight temps/dewpts. The short-range
model that seems to be doing the best is the RAP at the moment,
and its mins are within a couple degrees of those from the previous
fcst. I weighted new hourly values more toward the RAP but kept
mins more or less as-is.
A very broad trough covers the eastern two thirds of the nation
attm. Mid and high clouds persist over the Piedmont, associated
with a jetlet stretching from the OH river valley to the New
England. Upper level RH trends indicate some drying as the jetlet
shifts slightly east, so these clouds are expected to gradually
become more patchy with time. Patchy fog near rivers, lakes, and
bodies of water will remain possible but should be fairly shallow.
A weakly reinforcing cold front, with little to no moisture, will
move through the region on Monday to bring in slightly cooler
and drier air. Maxes will be about a category below climo Monday
afternoon.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 230 PM EDT Sunday: The short term fcst period kicks off
on Monday evening amidst broad H5 troffing across much of the
east/central CONUS, while a series of shortwave impulses pass
through the mean flow aloft. At the surface, a weak/dry cold front
will be making its way into/through the high terrain of western NC
as high pressure slides east across the TN Valley. Given the drier
nature of this fropa as well as a lack of any sig shortwave energy,
will keep the fcst dry through the overnight hours. However,
by early/mid Tuesday afternoon a slightly more potent shortwave
will accompany another reinforcing cold front, which will dive
through the OH valley into east TN/KY then western VA/WVA by
Tuesday evening. Given improved convergence along the front as
well as weak upper forcing thanks to the shortwave, think convection
will be possible across the aforementioned areas, eventually moving
at/into western NC by late day Tuesday. Therefore the fcst will
feature slight/chance pops across portions of western NC with the
highest pops being across the mtns along/north of I40. Beyond that,
broad surface high pressure will consume the fcst area for Wednesday
leading to pleasant conditions. Temperatures/dewpoints will be the
primary highlight of this fcst period as highs top out each day
nearly 6-8 degrees below normal, with dewpoints in the lower/mid
50s yielding low RH values.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 155 PM EDT Sunday: No sigfnt changes needed to the going fcst.
The models continue to show the transition from a unseasonal trof /
Canadian sfc high config into more of a normal summertime pattern.
There shud be enuf llvl moisture adv for mtn top convg shrs/tstms
Thu afternoon but coverage will be limited as upper heights rise and
a subtrop ridge noses in from the east. Things become more
interesting Fri thru the period as sfc-based instability increases
and easily breaks a weak cap each afternoon allowing for stronger
diurnal convection with better coverage...mainly across the higher
terrain Fri. Mid level LRs increase to arnd 6.5 C/km on Sat associated
with an incoming h5 s/w which will develop stg/svr activity over the
mtns/fthills spreading east across the piedmont regions thru the
late afternoon and evening. A cold front approaches the FA late Sat
and there is decent agreement in the guidance to suspect the front
will push into the FA and become quasi-stationary Sun. Thus...above
normal coverage will be had with thunder activity developing within
a continued unstable atmos. Max temp will begin the period a little
lower than normal and increase to near or just above normal by the
weekend. Mins will also rebound to normal levels in an increasingly
moist environ.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: A persistent area of enhanced upper level
flow over the Ohio Valley and Northeast states, in the exit
region of a trough, will continue to bring some high cloud cover
overnight. However, the axis of better moisture should gradually
shift east and lead to partial clearing. Flow will remain light
northerly through most if not all of the period. Some guidance
suggests lee troughing after 18z Mon and associated backing, but
confidence is low on wind shifting out of the NW quad, except at
KAND. Low level conditions appear much too dry for restrictions
except in the Little TN River valley of SW NC.
Outlook: Light winds and VFR conditions should continue through
most of the week. Return flow moisture will return around the
offshore ridge Thursday into Friday.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...SBK
NEAR TERM...HG/Wimberley
SHORT TERM...CDG
LONG TERM...SBK
AVIATION...Wimberley
Area Forecast Discussion
National Weather Service Lake Charles LA
704 PM CDT Sun Jun 25 2017
.DISCUSSION...
For 00z TAF issuance.
&&
.AVIATION...
Maintaining VC mention at all srn terminals first hour or so given
activity currently associated with weak passing sfc boundary noted
on local 88Ds...thereafter expecting a quiet night rain-wise with
loss of heating. Not expecting much in the way of low clouds
overnight given lack of sfc-h9 moisture in forecast time-height
sections. After sunrise, expecting VFR conditions to continue to
prevail although VCSH was re-introduced as the front meanders
around the region.
25
&&
.PREV DISCUSSION... /issued 315 PM CDT Sun Jun 25 2017/
DISCUSSION...
Weather map show frontal boundary to the coast with northeasterly
winds behind it. Slightly drier air with dewpts in the upper 60s
across Central Louisiana, but further south dewpts still in the
mid/upper 70s. Radar shows much less convection than expected
earlier. Left 50% for SE TX/S LA into the coastal waters for the
next couple of hours of max heating, as the HRRR still insists of
development. After sunset this evening, lingering convection if
any should be confined to the coast and coastal waters. Slightly
cooler and drier air will only be noted across Central Louisiana,
where overnight lows will dip into the upper 60s. Elsewhere, lower
to mid 70s expected.
With the frontal boundary expected to remain nearly stationary
along the coast and coastal waters, at least a lower end chance of
showers and a few thunderstorms will remain across SE TX/S LA
Monday and Tuesday. By Wednesday, the front is expected to
dissipate with a predominate southeast flow resuming across the
region, bringing with it increased Gulf moisture and higher
chances of showers and thunderstorms. This trend should continue
into Thursday, with precipitation chances gradually diminishing to
near climatological ~20-30% for the weekend as high pressure aloft
gradually builds westward over the region.
DML
MARINE...
Light northeast to easterly winds expected this evening and
overnight as a weak frontal boundary stalls near the coast, with a
chance for showers and thunderstorms. Winds and seas will be
higher near the storms. High pressure will ridge across the
northern Gulf by mid-week, providing a more predominate moderate
southeast flow and increased seas by Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 68 88 69 88 / 20 20 10 30
LCH 73 87 73 87 / 30 30 20 40
LFT 71 87 71 87 / 30 30 20 40
BPT 73 87 73 88 / 30 30 20 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Memphis TN
910 PM CDT Sun Jun 25 2017
.DISCUSSION...Surface analysis this evening places a weak cold
front from the Ohio Valley back through Southern Missouri and
Southeast Kentucky. Skies are clear to mostly clear across much
of the Mid-South with temperatures as of 8 pm CDT in the 70s at
most locations.
Latest short term models including the HRRR indicate a potential
for a few rain showers to occur late tonight into Morning across
portions of northeast Arkansas. I think this will be mostly
occurring on Monday and will trim rain chances back overnight.
Otherwise, the remainder of the forecast is in good shape overall.
CJC
&&
.PREV DISCUSSION... /issued 624 PM CDT Sun Jun 25 2017/
UPDATE...
Updated to include the 00z aviation discussion.
PREV DISCUSSION... /issued 244 PM CDT Sun Jun 25 2017/
DISCUSSION...
With the exception of locations southeast of Tupelo, the Mid-
South is experiencing a gorgeous afternoon with plenty of
sunshine, pleasant temperatures, and low humidity. Pesky clouds
remain over locations from Southern Calhoun to Southern Itawamba
Counties. The clouds should clear by the early evening hours.
Expect tranquil weather for the CWA for the evening hours. By
midnight, clouds associated with a shortwave currently over Kansas
will begin to push into Northeast Arkansas. Chances for showers
will occur after midnight for portions of Northeast Arkansas and
the Missouri Bootheel. The showers may continue into early Monday
afternoon before dissipating.
With the area remaining in northwest flow aloft, another shortwave
will bring chances for showers Monday Night into Tuesday across
the northern half of the CWA. The upper flow will become more
zonal by Tuesday evening ending the chances for showers.
SFC high pressure will shift east Tuesday Night which will allow
SFC winds to turn around to the south. The southerly winds will
bring higher dewpoints back into the area resulting in higher
humidity.
Chances for diurnal convection will begin to occur Thursday
afternoon across portions of North Mississippi. Chances will
spread to the entire Mid-South on Friday.
Best chances for showers and thunderstorms will come next weekend
as a cold front moves into the Mid-South and stalls out over the
region.
As for temperatures, highs will be in the 80s this week. Lows
will generally be in the 60s early in the week increasing to the
lower 70s by the end of the week.
KRM
&&
.AVIATION...
/00z TAFs/
Clear skies this evening will give way to increasing mid-level
clouds as an upper-level jet max approaches. VFR conditions will
prevail through the TAF period with light and variable winds
overnight becoming northeast at 5-7 kts on Monday. A few showers
are possible from the mid-level cloud cover north of I-40, so a
VCSH group was included at KJBR after 13z and MKL after 16z.
Johnson
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service New York NY
1102 PM EDT Sun Jun 25 2017
.SYNOPSIS...
A weak low pressure troughs will form over land Monday and move
offshore Monday night. A cold front crosses the region Tuesday
afternoon with high pressure building to the south of the region
for Wednesday. A warm front crosses the region late Thursday
followed by warm, humid and unsettled weather on Friday though
the weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The fcst is on track with no major changes made.
Latest satellite imagery shows upper low just north of Lake
Ontario with another shortwave that has kicked off more
scattered showers from BGM down to Central PA. Extrapolation of
this suggests arrival is not until just after midnight. The
latest HRRR suggest new activity feeding off the mid level
instability and latest GOES-16 visible data support at least
some of this with moderate CU seen over Eastern PA. Sounding
shows all instability is below the -20 C level - so only
expecting showers. Have gone with a 20 to 30 POP for now.
Overnight lows fall into the 50s and 60s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Another weak surface trough develops over the area Monday.
Aloft, heights fall to the west of the area as next shortwave
moves across the Great Lakes region.
Plenty of sunshine Monday morning, gives way to a some
afternoon clouds especially north and west of NYC. A few
isolated showers will again be possible across the interior.
Dry conditions are expected Monday night.
Temperatures on Monday will climb into the 70s and lower 80s.
Monday night, lows fall into the 50s and 60s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Looks fairly dry with comfortable humidity and slightly below normal
temperatures through mid week. A warm front approaches on Thursday
as low pressure passes across southern Canada. In its wake, a cold
front sags south into NY State on Friday. The front becomes
stationary near the region into the weekend - which appears will be
"unsettled."
Upper trough axis approaches Tuesday, passing Tuesday night. Perhaps
a tad more instability Tuesday and trof/pseudo cold FROPA triggers a
showers and perhaps a TS (instability is limited with dry mid
levels).
Wednesday is dry and then warm advection starts in on Thursday.
Frontal boundary in the region, or just north, on Friday and have
POPs in for TSRA. Looks to remain unsettled through the holiday
weekend at this time. LI`s as low as -5 C with long narrow CAPE`s
and PWAT`s over 2 inches in a unidirectional flow supports
potential for Flash Flooding - mainly in urban areas.
Temps come back to near seasonable on Thursday and then go above
Friday into the weekend. No heat issues foreseen though.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
High pressure will remain s of the region thru the taf period.
SW winds become light WNW overnight, and SW close to 10 kt by
Mon afternoon, with coastal sea breeze development by 15Z-16Z.
An isold shra is possible thru 6Z. Outside of any shwrs, vfr
thru the taf period.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.Monday night...Mainly VFR. Coastal sea breezes. Slight chance
of an eve shower/tstm NW of NYC metros.
.Tuesday...Mainly VFR. Chance of a late day shower/tstm.
.Wednesday...VFR.
.Thursday...Mainly VFR. Chance of a late day shower/tstm mainly
north of the NYC metros and Long Island.
.Friday...Mainly VFR. Chance of a late day shower/tstm at KSWF.
&&
.MARINE...
Winds and seas will remain below small craft levels through
Monday night. Ocean seas will likely build to SCA criteria late
Thursday and continue as such into Friday.
&&
.HYDROLOGY...
No hydrologic impacts expected through Thursday. There is potential
for localized flash flooding associated with summer convection
Friday through the weekend - mainly in urban areas. River flooding
is not anticipated.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides are running high, especially during the
nighttime high tide cycles.
Main area to watch would be across the Nassau south shore bays,
where water levels should briefly touch or barely exceed minor
thresholds this evening. The times of high tide are from 9-11pm.
&&
.EQUIPMENT...
Observations from KFRG (Farmingdale, NY) are not available.
Observations from KHPN (White Plains NY) and KHVN (New Haven CT)
are being disseminated through backup methods. All is due to
an FAA communication line outage. Return to service time is
unknown.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BC/Tongue
NEAR TERM...BC/JMC/Tongue
SHORT TERM...BC
LONG TERM...Tongue
AVIATION...JMC/Goodman
MARINE...BC/Tongue
HYDROLOGY...BC/Tongue
TIDES/COASTAL FLOODING...
EQUIPMENT...
Area Forecast Discussion
National Weather Service Norman OK
951 PM CDT Sun Jun 25 2017
.UPDATE...
Adjusted POPs for this evening and overnight. Otherwise forecast
is in good shape.
&&
.DISCUSSION...
First, lowered POPs northwest for this evening as earlier
convection has dissipated. Still continue with a few elevated
echoes over central Oklahoma and more showers in northeast
Oklahoma, so will maintain slight chance pops in northern and
central portions of the area.
Out west, the HRRR has been developing convection on the east side
of the current complex in the panhandles and moving that southeast
into southwestern portions of the area. Convection has not been
developing as far east as the HRRR suggested and more recent runs
have been backing off on that scenario. Still, there is some
signal in both the HRRR and RAP of some development approaching
far southwestern sections, so have added a sliver of chance pops
in far southwest Oklahoma and the western counties of north Texas.
&&
.PREV DISCUSSION... /issued 605 PM CDT Sun Jun 25 2017/
AVIATION...
VFR conditions to continue. Will maintain a mention of shra at both
GAG/WWR for an hour or two and will intro a chance at PNC. Could be
a few shra/tstms across southwest OK into north TX during the
morning hours on Monday, but confidence remains to low to mention in
the TAFs at this time.
30
PREV DISCUSSION... /ISSUED 249 PM CDT Sun Jun 25 2017/
DISCUSSION...
The main forecast challenge is determining rain chances now
through Tuesday.
Through this evening, believe isolated to scattered showers and
perhaps a few thunderstorms will affect parts of mainly western
and northern Oklahoma. Light radar echoes over southwestern
Oklahoma as of 245 pm will likely continue to weaken as they move
southeast this afternoon, encountering a drier and more stable
airmass. Most rain this evening appears to be in the form of showers
and a few thunderstorms moving southeast from Kansas, likely from
a stronger mid level disturbance in northwestern mid/upper flow.
This activity will continue to spread southeast this afternoon and
evening, at least into northwestern Oklahoma, and generally is
expected to weaken as it moves into drier and more stable air.
Regardless, increased rain chances slightly this evening across
northwestern Oklahoma from this activity. A few rumbles of thunder
will be possible over western Oklahoma where MUCAPE values
100-700 J/kg are forecast, though no severe storms are expected
from the limited instability. Rainfall should remain light for the
most part and under 0.25".
After midnight tonight, not sure what exactly will happen, but
kept 20% chances for weak showers and thunderstorms west of a
Seymour, TX to Clinton to Ponca City line where there seems to be
a slightly stronger model QPF signal. Mid level moisture remains
abundant across much of the area, so even weak isentropic
mid level lift could trigger some weak high based showers and
perhaps a few thunderstorms. Do not expect widespread rains.
Monday looks to be fairly similar to today. Kept low rain chances
mainly over western Oklahoma with possible weak showers and
storms during the morning hours in this area. Western north Texas
may have some showers and thunderstorms, particularly during the
afternoon hours as the air becomes increasing moist (precipitable
water values 1.5-1.9") and unstable (MLCAPE 1000-2000 J/kg) which
would support perhaps a few strong storms with gusty winds, small
hail, and locally heavy rainfall. Temperatures should stay
slightly below average and mainly in the 80s.
Monday night into early Tuesday, there appears to be a signal that
storms may move into at least the northern half of Oklahoma from
Kansas. Increased rain chances slightly to account for this.
Severe potential remains low as these storms would be weakening as
they head south since the air should be more stable in northern
Oklahoma compared to Kansas. Additional weak showers and storms
may be across the area, though confidence is low.
Tuesday afternoon appears to be breezy, hotter, and more humid.
Increasing mid level temperatures should allow for stronger
capping, decreasing clouds, and diminished chances for rain.
Tuesday night into early Wednesday, there may be additional
showers and storms mainly over northern Oklahoma. Breezy and humid
weather can be expected.
Wednesday and Thursday, breezy to windy and hotter weather can be
expected. This may elevate fire weather conditions.
Thursday night through next Sunday, there still appears to be
signal for wetter conditions across the area, mainly across
northern Oklahoma, during this time frame. Increasing instability
and moisture combined with some weak mid/upper level troughing
and perhaps a weak front may allow for showers and thunderstorms,
some of which could be strong to perhaps severe, and produce
locally heavy rainfall. Kept rain chances in the forecast in many
areas. Not confident at all that widespread rainfall will occur.
Rain chances may decrease by Sunday along with the arrival of hotter
conditions as possible mid/upper level ridging moves into the
southern Plains.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 64 85 66 88 / 20 10 20 10
Hobart OK 64 84 66 89 / 20 20 20 10
Wichita Falls TX 67 85 68 89 / 10 20 10 10
Gage OK 61 84 64 88 / 20 20 20 20
Ponca City OK 62 86 64 88 / 20 10 40 20
Durant OK 66 86 67 88 / 10 10 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
Area Forecast Discussion
National Weather Service Mount Holly NJ
626 PM EDT Sun Jun 25 2017
.SYNOPSIS...
A large area of high pressure will slowly move through the eastern
U.S. early this week before moving offshore Wednesday and Thursday.
A series of surface lows will move from the northern and central
plains to the Great Lakes and Northeast from mid to late week,
ushering in warmer and more humid air late this week and the
upcoming weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The mid and upper level shortwave trough now over the eastern
Great Lakes region will lift northeast through the evening and
early overnight hours. A few additional showers are possible
across portions of the CWA through the early evening hours.
However, after 00Z, the diurnally driven activity will
dissipate. The latest run of the HRRR indicates that even the
more widespread shower activity associated with the main trough
axis now in western Pennsylvania will also dissipate by
midnight.
Temperature wise, as the drier air continues to filter into our
area, expect efficient radiational cooling to result in lows
slightly below normal, ranging from the lower 50s to mid 60s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
Main story through this period is a cold front at the surface which
will approach our region late in the day. There may be enough lift
with this to once again result in isolated convective initiation
across the higher terrain of eastern PA and NW NJ.
In the mid and upper levels, an approaching trough will result in
decreasing 1000 to 500 mb thicknesses which should also translate to
slightly lower temperatures than what we have seen lately. Highs are
expected to range from the upper 60s in the higher terrain of the
Poconos to the lower 80s across central Delmarva.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Main forecast challenges for the long term include a deep trough
passage around midweek and increasing warmth and precipitation
chances late week into this weekend.
A potent shortwave trough is poised to move through the larger-
scale trough in eastern North America early this week, with
passage through the northeastern U.S. in the Tuesday-Wednesday
time frame. Large-scale ascent in advance of the attendant
vorticity maximum will allow for increased cloud cover on
Tuesday and fairly cool temperatures for this time of year.
Forecast highs are around 5-10 degrees below seasonal averages.
Forecast confidence is a little below average on Tuesday,
however, given some lingering disagreement among the operational
models regarding strength/orientation of the trough axis,
extent of large-scale ascent in advance of the trough in the
Mid-Atlantic, and associated frontal timing. The 12Z GFS/CMC are
fairly dry across the area, but the 12Z ECMWF does generate
some precipitation along the front and offshore. Though there is
much improved agreement on the specifics of a developing low
off the coast with the 12Z simulations, the QPF discrepancies do
not bode much confidence in the sensible weather details,
particularly in southern/eastern portions of the area -- which
will be in closer proximity to the developing low and the last
to be passed by the remnant surface boundary moving through the
region. Decided not to stray much from forecast continuity for
this period.
Upstream ridging will move into the East on Wednesday, with a
broad surface high migrating to the coast by 00Z Thursday. This
should allow for a dry day with continued pleasant (slightly
below average) temperatures.
As the surface ridge moves offshore by Thursday, return flow
commences. Temperatures are likely to rapidly warm in this
regime, with substantial warm/moist advection occurring in
advance of another potent vorticity maximum moving into the
Great Lakes and adjacent southern/southeast Canada by this time.
Midlevel ridging in advance of the vort max should permit the
warm sector to surge well north of the area, which will prevent
associated surface fronts from reaching the area likely through
the end of the long term period.
This means the main questions regarding the Friday-Sunday
forecast revolve around heat/humidity and chances for
precipitation, as the rapid warmth of Thursday will likely be
followed by more gradual increases in temps/dew points
thereafter. Additionally, with the Mid-Atlantic becoming more
and more on the fringes of midlevel ridging, large-scale ascent
(pronounced in advance of west-to-east moving vorticity maxima)
will at least glance the area, especially the northern/western
CWA. As such, the models (to varying degrees) suggest increasing
chances for precipitation as a surface boundary sags southward
from Canada through this period.
There is pretty decent agreement on timing/location of the first
vorticity maximum on Thursday (generally in New York/New
England), so kept PoPs pretty low in the CWA during this time
frame (only mentionable in the southern Poconos and vicinity).
However, Friday through Sunday feature increasing chances for
convection as faster southwest flow slowly edges toward the area,
though pinpointing exact locations and timing (the latter of
which will be closely tied to upstream vorticity maxima this
weekend) is a dubious exercise at this time range given the
somewhat unpredictable pattern (and associated poor phasing
agreement among the ECMWF/GFS/CMC). Generally broad-brushed
slight chance to chance PoPs through the CWA this weekend as a
result, with a general blend of the above-mentioned models and
heavy weighting to continuity/WPC guidance.
Regarding heat/humidity, kept the forecast fairly tame during
this period (and close to statistical guidance) given potential
complications from proximity convection. However, if the ridge
remains more prevalent across the area, forecast could be too
cool this period. Regardless, a sultry weekend is anticipated.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Mostly VFR conditions are expected through the TAF period. There is
a slight chance showers and thunderstorms after 18Z Monday across
the higher terrain (including KRDG and KABE). If any showers move
over the TAF sites, MVFR or lower conditions are possible, but it is
too uncertain to include in any of the TAFs at this time.
Winds will stay mostly light out of the west or southwest through
the TAF period. The one exception is KACY, where south southeasterly
winds are expected to persist through at least 00Z in the wake of a
sea breeze. There is a chance a sea breeze could redevelop after
18Z Monday and once again shift the winds at KACY.
OUTLOOK...
Monday night and Tuesday: Predominantly VFR, though
isolated/scattered showers/storms are possible. Winds generally
west or southwest 5 to 15 kts with gusts to 20 kts during the
day. Confidence average.
Tuesday night through Wednesday: VFR. Winds generally northwest
5 to 15 kts. Confidence above average.
Wednesday night and Thursday night: VFR. Winds generally
southwest under 10 kts at night and 10 to 20 kts during the day.
Confidence above average.
Thursday night and Friday: Generally VFR, though there is an
increasing chance for showers/storms, especially north/west of
KPHL during this period. Winds generally southwest 5 to 15 kts
with gusts to 20 kts during the day. Confidence below average.
&&
.MARINE...
Winds and seas are expected to stay below small craft advisory
criteria tonight and tomorrow. Westerly wind gusts up to 20 kt are
possible on the Atlantic coastal waters overnight, but should stay
below 25 kt.
OUTLOOK...
Monday night through Wednesday night: Sub-advisory conditions
expected. A slight chance of showers/storms on Tuesday and
Tuesday night.
Thursday through Friday: Advisory winds/seas possible as
stronger southwesterly winds become established. A slight chance
of storms on Friday.
.RIP CURRENTS...
The outlook for tomorrow is that the low risk for the formation of
dangerous rip currents will continue.
&&
.TIDES/COASTAL FLOODING...
Very high astronomical tides are expected to continue today and
tomorrow. There is a chance that minor tidal flooding could occur
especially along the northern NJ shore with the high tide cycle this
evening. However, models over the last few days have had a high
bias, and the winds have been light though the day today. Therefore,
do not expect widespread tidal flooding today. Tomorrow water levels
should be slightly lower as well.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
Synopsis...CMS
Near Term...Johnson/Miketta
Short Term...Johnson
Long Term...CMS
Aviation...CMS/Johnson
Marine...CMS/Johnson/Miketta
Tides/Coastal Flooding...Johnson