Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/11/19
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1021 PM EDT Mon Jun 10 2019
.SYNOPSIS...
A frontal system will cross the area tonight, proceeded and
accompanied by showers with localized heavy rain. High pressure
will build east across the area on Tuesday accompanied by
clearing, breezy and mild weather. Wednesday will be a dry,
sunny and seasonably warm day, then the next chance of rain will
be Thursday as low pressure approaches from the west and south.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 1000 PM EDT...00Z local sounding reveals a fast reversal
from the weekend as it appears we hit a new PWAT record for the
00Z/11th of 1.94". So while the atmosphere is quite moist,
overall precip rates remain between one and two tenths of an
inch per hour with slightly higher values into the Catskills.
Main issue is lack of deeper instability, main upper jet
dynamics are way displaced and a rather progressive nature of
upstream trough. H2O vapor imagery is equally impressive with
the subsidence upstream in the wake of the upper trough passage
as evident from KDTX sounding. So main update was to remove
thunder from the grids, enhance PoPs per regional radar and
forecast trends per HRRR and temperatures per observations.
Temperatures not changing too much overnight as well.
Prev Disc...
A large area of light to moderate overrunning rain will
overspread eastern NY and western New England late this
afternoon as high pressure retreats off the east coast and a
cold front approaches from the west. Low-level south-
southeasterly flow will increase to 30-35 kts this evening
bringing a rapid increase in deep-layer moisture across the area
with precipitable water values approaching 2.0 inches. These
winds aloft could also translate into some gusty surface winds
with speeds as high as 25 mph over favored locations along the
west slopes of the Taconics and Greens. The rapid increase in
moisture and isentropic lift will result in a first batch of
rain moving across the area late this afternoon through early
evening with rainfall amounts averaging between 0.25 and 0.50
inches.
There could be a break in the steadier rain later this evening,
then another area of showers associated with the cold front
will move across the area after midnight. These showers may be a
bit move convective than the first showers with instability
mainly elevated above surface as Showalters fall to around -1.
There should be no severe risk with these showers, however they
will be associated with plenty of deep-layer moisture and deep
warm cloud depths so localized heavy rain will be a possibility
as the low-level southerly jet increases to around 40 kts
shortly after midnight. Area rainfall will average around an
inch for much of the area with the best chance for more than
inch south and east of the Capital District, as well as over
south facing slopes in the southern Adirondacks and southeast
facing slopes in the eastern Catskills. Some localized areas
could see as much as 2.0 inches given the unusually large
precipitable water values expected with the passage of the
front. Dry weather over the past few days has resulted in rather
dry antecedent conditions and at this point it appears that any
flood risk will be confined to localized poor drainage
flooding, so no flood watch will be issued at this time. Will
continue to mention localized heavy rain and minor poor drainage
flooding concerns in the hazardous weather outlook.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
Showers will be over early Tuesday morning as the front moves
east of the area. High pressure will build across the area
during the day with westerly breezes gusting to 20 to 25 mph and
clearing. Temperatures will be a bit below normal for mid June
with highs in the lower to mid 70s. Tuesday night and Wednesday
will be quiet and calm with high pressure moving east of the
area. Temperatures Wednesday afternoon will be near normal with
highs in the mid to upper 70s. The next chance of rain will be
Thursday as an unseasonably strong mid-level trough approaches
from the west. At the surface, low pressure will be deepening
over the eastern Great lakes while a secondary area of low-
pressure will form near the mid-Atlantic coast and will track
northeast toward New England. This pattern is far more typical
for early spring or late fall than early mid June and will
likely result in a period of rain on Thursday with unseasonably
cool temperatures. Have lowered temperatures a few degrees below
model blends for Thursday afternoon with many places out of the
Hudson Valley probably not getting out of the 50s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
The long term forecast period synoptic flow pattern will be
dominated by anomalous long wave troughing over the eastern CONUS
with multiple chances for shortwave troughs to interact and produce
unsettled weather across eastern New York and western New England.
An unseasonably deep upper trough and surface double barrel low will
be lifting northeastward across the region as we begin the long term
period Thursday night. Rain will linger across the region through
the first half of Friday before mid level ridging and surface high
pressure builds into the Mid-Atlantic region and tries to dry
conditions up. There are signals from the latest deterministic
global model runs that keep rain along and north of I-90 for the
entire day, but there has been little run-to-run consistency and
there is a large amount of spread resolved in ensemble guidance on
the eastern side of the mid level trough, suggesting low confidence
in the placement and timing of the tangible weather at the surface.
Have gone with slight chance to chance PoPs for the region on Friday
as of now. There will be a strong pressure gradient in place with
the low to the north and a high building in from the south, as well
as good mixing potential into a strong low level jet, as suggested
by forecast soundings, so conditions will likely be breezy with
winds out of the west on Friday. This flow pattern combined with the
favorable forecast soundings provided confidence to go above the
blended guidance and increase wind speeds/gusts for the Friday
afternoon time period. Beyond Friday, deterministic guidance differs
greatly with respect to the general flow pattern and how that
impacts low level features and our tangible weather.
Some guidance continues to build the high pressure into the region
for Saturday followed by multiple cold fronts progressing across the
region throughout the weekend into next week, while other guidance
resolves a quasi-stationary east-west oriented boundary across the
region over which multiple pieces of short wave energy traverse
throughout the weekend into early next week. Have kept slight chance
PoPs in the forecast for Saturday due to the low confidence nature
of the forecast, followed by chance PoPs for just about the entire
region for the remainder of the forecast period.
Temperatures for the long term period will be near or slightly below
normal for this time of year with high temps over the high terrain
being stuck in the mid-to-upper 60s and the valley regions seeing
highs in the low-to-mid 70s. Lows will generally be in the 50s, with
the high terrain dipping into the 40s.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
VFR to MVFR flight conditions expected through the early evening
hours as periods of rain and showers impact the region. Aloft,
strong wind magnitudes from the south-southeast warrant the
continuation of LLWS in the TAFs. A period of IFR conditions are
possible toward and after midnight with deeper moisture and
showers, especially into KPSF.
Cold front is expected to sweep across the region from west to
east between 09-11Z. Winds will quickly shift from the southerly
to westerly direction and increase in magnitudes. In fact, gusts
occasionally over 20kts are expected through most of the day
Tuesday as skies and visibility improve to VFR.
Outlook...
Tuesday Night: Low Operational Impact. Breezy NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: Low Operational Impact. Slight Chance of SHRA.
Thursday: High Operational Impact. Likely SHRA...TSRA.
Thursday Night: High Operational Impact. Likely SHRA.
Friday: Moderate Operational Impact. Breezy Chance of SHRA.
Friday Night: Low Operational Impact. Slight Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.
&&
.FIRE WEATHER...
West to northwest winds will gust between 25 and 35 mph on Tuesday...
Showers will fall ahead of a frontal system tonight, with
localized heavy rain possible. High pressure will build back in
with breezy, drier and cooler conditions Tuesday. Dry and
seasonably mild weather is expected Tuesday night and Wednesday.
Relative humidity will increase to maximum values of around 90
to 100 percent tonight. Minimum RH values will be around 40 to
55 percent Tuesday afternoon.
Winds will be from the southeast at 5 to 15 mph tonight with
localized higher gusts especially along the west slopes of the
Greens and Taconics. Winds on Tuesday will shift to the north-
northwest behind a cold front, and will increase to around 15 to
20 mph with gusts of 25 to 35 mph.
&&
.HYDROLOGY...
An increasingly moist air mass will return tonight, with an
upper level trough and a frontal boundary bringing a widespread
rainfall with isolated thunderstorms late this afternoon into
the early morning hours Tuesday.
Some deeper, tropical moisture from the Southeast CONUS will
get drawn north into our region, as a very strong upper-level
disturbance and cold front track through our region tonight into
Tuesday morning. This is expected to result in isolated
thunderstorms and localized heavy rainfall with some urban and
small stream flooding possible. Current forecast rainfall
amounts are close to an inch across most of the hydro service
area, with localized 2 inch amounts. At this time, it appears
that the heaviest rains could produce localized minor flooding
in poor drainage areas, but flooding will not be significant
enough or widespread enough to warrant a watch at this time.
Dry weather returns Tuesday into Wednesday. A coastal low may
bring another widespread soaking rainfall to the region late
Wednesday night through Thursday, which may cause some increased
flows on the rivers. Their is still some uncertainty on the
track of the wave and the amount of rainfall it will bring to
the Hydro Service Area. Overall, the latest MMEFS guidance does
not show any flooding on the main stem rivers at this time.
Some isolated to scattered showers will bring light rainfall
amounts on Friday before dry weather may briefly return on
Saturday.
Please visit our Advanced Hydrologic Prediction Service /AHPS/
web page for specific area rivers and lakes observations and
forecasts.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE/BGM
SHORT TERM...MSE/JPV
LONG TERM...Cebulko
AVIATION...BGM
FIRE WEATHER...JPV
HYDROLOGY...JPV
Area Forecast Discussion
National Weather Service Bismarck ND
954 PM CDT Mon Jun 10 2019
.UPDATE...
Issued at 954 PM CDT Mon Jun 10 2019
Minor adjustments were made with this update, again primarily to
PoPs based on radar trends. In general convection is decreasing
with the onset of boundary layer cooling and related reduction in
already-weak MLCAPE, though upstream radar imagery suggests that
isolated showers could continue moving into western ND overnight.
Thus, while we foresee a relative lull in precipiation coverage
before the next upstream shortwave trough moves into the area on
Tuesday, we have chosen to keep relatively broad-brushed and low
PoPs in place over western ND most of tonight in a collaborative
move with NWS Glasgow. Otherwise, we did forego any thunderstorm
mention the rest of the night based on recent trends and a lack
of CAPE.
UPDATE Issued at 552 PM CDT Mon Jun 10 2019
Only minor changes were made with this update, and were focused on
hourly PoP adjustments through the evening -- namely to increase
coverage of isolated showers/storms over western ND based on radar
trends through 2245 UTC, and to increase PoP values into the 30 to
50 percent range downstream of the more concentrated convective
cluster centered on Kidder and Logan Counties as of this writing.
Time-lagged HRRR guidance also captured these trends well and our
hourly forecast fields were weighted toward it through 03 UTC. The
environment is characterized by weak bouyancy -- though a shallow
moist layer with dewpoints in the 40s F south central is yielding
SBCAPE to around 1000 J/kg, MLCAPE, which may be more reflective
of what updrafts have access to, is limited around 250 J/kg. This
will continue to limit updraft intensity despite steep low- and
midlevel lapse rates and modest flow aloft, which will nonetheless
continue to support occasional small hail or gusts with stronger
convective cores. Finally, lightning production has been limited
in southwestern ND, and may continue to be, as objective analysis
data suggests equilibrium levels are only near the -15 C altitude
there, not quite cold enough for significant charge separation.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 339 PM CDT Mon Jun 10 2019
Main forecast issue in the short term period will be showers and
thunderstorms This afternoon through Tuesday within a northwest
flow pattern.
Showers, and isolated thunder has developed over portions of the
northwest and south central where daytime heating and low level
moisture were maximized. Do expect the area of showers and
thunderstorms to expand this afternoon. Northwest into central
ND would be a favored area for some stronger cells this afternoon
with around 1000 J/Kg MUCape and 35 knots of bulk shear. We could
see some locally gusty winds and small hail with the stronger
cells.
Another wave moves through the area tonight into Tuesday morning,
which will probably keep some isolated to scattered showers around
through the night, but the threat for thunder should drop rather
quickly by early to mid evening.
More widespread showers and thunderstorms are expected on Tuesday.
A shortwave moves through during the morning with another dropping
south closer to eastern North Dakota, which will be accompanied
by a surface cold front. The areal coverage of convection is
expected to be more widespread than the last couple of days, thus
pops are high chance into the likely category. The threat of
severe weather is a bit higher than the last couple of days, over
south central into southeast North Dakota. Although the
instability is expected to be greater, bulk shear is rather weak.
A few stronger to possibly severe storms can not be ruled out
Tuesday afternoon, but overall, think the potential is pretty low.
The SREF calibrated severe parameter is pretty low and has been
trending lower the past couple of runs. Will separate out south
central for increased severe potential compared to the rest of the
CWA.
.LONG TERM...(Tuesday night through Monday)
Issued at 339 PM CDT Mon Jun 10 2019
As this activity slides off to the east, surface high pressure will
begin to build over North Dakota as northwest flow aloft persists
Tuesday night through Thursday. Think that most areas will remain
dry these two days, but at this time, don`t think you can
completely rule out a stray shower or thunderstorm either day.
Long range guidance is struggling to come to a consensus for
Friday into the weekend. There are signs that a closed upper low
will either park itself over Ontario, or even retrograde back
farther to the west. It still appears there would be some sort of
northwest flow over the area, with occasional chances of showers
and thunderstorms. However uncertainty at this time is high.
Temperatures appear to moderate some by the weekend, but it does
not look as warm as previous forecast cycles suggested with highs
now forecast to mainly be in the 70s Friday through Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 954 PM CDT Mon Jun 10 2019
VFR conditions will generally prevail through the 00 UTC TAF
cycle. Isolated showers remain possible overnight, but coverage
will likely be limited between 06 and 12 UTC. Otherwise, on
Tuesday a more widespread area of showers and storms will develop,
especially by afternoon, with coverage highest central and south.
Local MVFR conditions are not out of the question with the more
intense cells after 18 UTC Tuesday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...CJS
Area Forecast Discussion
National Weather Service Denver/Boulder CO
858 PM MDT Mon Jun 10 2019
.UPDATE...
Issued at 850 PM MDT Mon Jun 10 2019
Another quiet evening across Northern Colorado with a mainly dry
and stable airmass in place with no changes to evening forecast.
Colorado remains under northwest flow while a upper trof will
sweep across the northern plains later tonight and Tuesday. An
associated cold front will push into northeast Colorado during the
morning with increasing north to northeast low level flow
developing. Some increase in clouds during the afternoon with
possible isolated showers over the plains.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 315 PM MDT Mon Jun 10 2019
Quiet weather day across the area. Gusty south winds will linger
through the afternoon hours across eastern Colorado around a
surface high over the Southern Plains. Airmass is quite stable
today, even cumulus clouds are having a hard time forming. Not
surprising though, the 12Z sounding showed a strong cap near 600
mb. The HRRR shows a weak shower/storm forming over the Palmer
Divide and then tracking southeast and clipping southern Lincoln
county. Because of the cap and dry airmass, think it will be tough
for convection to form. Will keep very low PoPs in the forecast
for this. For the rest of the evening and tonight, expect skies to
be mostly clear. It will be cool again with lows in the 40s
across eastern Colorado.
For Tuesday, a cold front will push south through the area
12-15Z. Gusty north winds will prevail behind the front across the
plains. Highs will be cooler with readings in the lower to mid
70s over northeast Colorado. A short wave trough embedded in the
northwest flow aloft may trigger isolated convection Tuesday
afternoon. Best chance for this looks to be over northern Colorado
and across the eastern plains. Moisture is limited, so will keep
PoPs in the 10 to 20 percent range.
.LONG TERM...(Tuesday night through Monday)
Issued at 315 PM MDT Mon Jun 10 2019
Tuesday night through Wednesday, a large upper trough will be
centered over the central U.S. with an upper level ridge of high
pressure over the western states. Colorado will lie between these
two systems under the influence a moderate northwesterly flow aloft.
Models are showing a weak cool front moving across the northeastern
plains Tuesday night which should result in another relatively cool
June day on Wednesday. The atmosphere behind the front should
generally be dry and stable. Therefore, only isolated to widely
scattered afternoon and evening showers and storms are expected
mainly over the higher terrain.
On Thursday, the upper flow over Colorado becomes more westerly as
the large upper trough moves into the eastern U.S. and a weak upper
ridge of high pressure moves into western Colorado. This pattern
should allow temperatures to warm to near normal values. There may
be some return in low level moisture across the far northeast plains
during the day with both the NAM and GFS showing capes over 1500
J/KG by afternoon. The instability combined with a weak shortwave
could result in a few late afternoon and evening severe storms
across far eastern sections of the CWA.
Friday and Saturday look to be cooler and wetter across north
central and northeastern Colorado as the weak upper level trough
of low pressure, embedded upper level disturbances and associated
weak frontal surges move across the state. GFS forecast soundings
show limited CAPE and shear which could limit severe potential.
However, can`t rule anything out especially for the middle of
June. Models are also showing PW values gradually rising to over
an inch across of the plains. Therefore, any storms that form will
be capable of producing locally heavy rainfall.
On Sunday, the upper trough moves into the Central Plains States,
with a weak northwesterly flow aloft over Colorado. Models show
an increase in southeasterly surface flow across the plains resulting
in higher dewpoints, CAPE and directional shear during the
afternoon. If this verifies, could see a few severe severe
storms during the afternoon and evening. With PW`s still at or
above an inch, the storms will still be capable of producing
locally heavy rainfall. A similar pattern continues on Monday with
continued active weather and below temperatures expected.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 850 PM MDT Mon Jun 10 2019
VFR with varying amounts of mid and high level cloudiness expected
through the period. Denver cyclone in place as winds have shifted
northwest at BJC and just now at BJC. Weak cold front will shift
winds northerly Tuesday morning and continue through the
afternoon.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Entrekin
SHORT TERM...Meier
LONG TERM...Kalina
AVIATION...Entrekin
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
650 PM CDT Mon Jun 10 2019
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...VFR will generally prevail at the aerodromes through
the next 24 hours. Convection will occasionally impact BRO/HRL/MFE
also.
&&
.PREV DISCUSSION... /issued 332 PM CDT Mon Jun 10 2019/
SHORT TERM (Tonight through Tuesday Night): Mid-level high pressure
centered over Deep South Texas will continue to gradually slide
south and west, allowing for a couple weak shortwave impulses to
move through the flow. This combining with weak surface boundaries
and deep-layer moisture will lead to increasing rain chances this
afternoon and through the short term period. Surface flow will
continue to be light and out of the north with a weak cold front,
which should help reinforce seabreeze potential and rain chances
along the coast today and Tuesday. Convective-allowing models are
going pretty high on coverage, particularly the HRRR for this
afternoon and Tuesday morning, so may have to increase rain chances
on the next update. For now, have maintained 40 to 50%, with a
stronger impulse expected early Tuesday afternoon. With precipitable
water values ranging from 2.00 to 2.25", any showers or storms have
the potential to produce torrential rainfall rates of at least 1 to
2 inches per hour. This would lead to minor flooding of poor
drainage and low-lying areas. Models indicate a slight lull in
activity overnight tonight with another round of development along
the coast Tuesday morning and spreading westward through the day.
The main trough axis will move off the Texas coast overnight into
Wednesday morning, which would potentially be another good shot of
precipitation before heading into the long term. Increased rain
chances and cloud cover through the period should keep temperatures
down in the lower 90s for most areas.
LONG TERM (Wednesday through Monday): The big picture of the
forecast hasn`t changed over the past couple of days...but the
focus for precipitation is a bit more clear cut. The last of the
fairly vigorous short waves diving down the back side of
developing Mississippi Valley 500 mb trough slides through South
Texas and the western Gulf on Wednesday, which should activate the
continued moisture pool at least for the morning hours. GFS/ECMWF
trends favor the short wave moving farther into the Gulf by
evening, which should taper off/end precipitation. This should
happen by afternoon...but due to uncertainty in timing at 48 to 60
hours elected to run a 12 hour precipitation forecast in case the
situation slows a bit. Favored locations for the day will be the
lower Valley where likely PoP (60 percent) was added, with
isolated (20 percent) across the Rio Grande Plains.
Rainfall totals and rates are always difficult...but could be
locally big due to light winds/slow cell movement and any slight
enhancement due to the sea breeze. So while QPF is generally on
the light side (~0.25 inch or so), as we saw today, locally 2+
inches in stronger cells is never far away from reality...which
can cause brief nuisance flooding but is still welcome in the long
run as dryness from last weekend`s heat wave needs a break before
what is expected at the end of the short term.
Thereafter, the 500 mb ridge builds back east and the eastern edge reaches
the classic "La Canicula" position (though weaker than what we
just saw and what we will see in July) over Chihuahua to Coahuila
by the weekend and into Monday. Eastward extension of the ridge
into the central/eastern Gulf help strengthen surface high over
the eastern Gulf a bit, while short wave energy passing through
the southern/central Plains develops the quasi-permanent west
Texas through Sierra Madre trough. This situation will both end
precipitation and quickly return heat and higher heat index values
beginning Friday and continuing through Sunday, with levels
possibly approaching advisory (111) along and east of US 281/IH
69C as temperatures approach 100...likely reaching 100+ from
McAllen through Starr/Zapata Saturday or Sunday through next
Monday.
Unlike last weekend, however, the "Valley Wind Machine" will pick
up as well, with 20 to 25 mph and gusty winds in these same
areas...a little lower along the coast...for the weekend. Building
seas/swell/surf with a southeast component will kick up the south
to north longshore which will make swimming difficult to dangerous
for those who cool off in the water at the beach...something to
keep in mind for the next weekend of heat relief.
MARINE: A light surface gradient will maintain low seas and
light winds outside of convection through the period. Deep-layer
moisture combining with a couple upper-level disturbances will
increase rain chances offshore, with a few storms capable of
producing gusty winds and frequent cloud to water lightning.
Wednesday through Saturday Night: Slight seas and light winds
prevail early as pressure systems remain weak at the surface...to
continue through early Friday. Conditions deteriorate fairly
quick as the winds increase and long fetch does as well...with
seas quickly increasing to 5 to 7+ feet Friday night through
Saturday night in the Gulf. Mix-down of 30-35 knot low level winds
should reach 20 knots sustained over the open Gulf overnight
Friday and Saturday, with just a touch drop back Saturday as
marine layer won`t do much to reduce speeds. Laguna winds will
also threaten 20 knots and gusty, especially Saturday and Saturday
evening.
While winds are light Wednesday and perhaps into early Thursday,
mariners will need to keep an eye on convection as the
aforementioned short wave slides through the waters and keeps the
threat of thunderstorms going.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
AREA FORECAST DISCUSSION
National Weather Service Burlington VT
959 PM EDT Mon Jun 10 2019
.SYNOPSIS...
A moisture-laden frontal system approaching from the eastern
Great Lakes will bring developing overcast skies and periods of
moderate rainfall overnight. Rainfall amounts will range from a
half inch up to an inch, with the higher amounts expected
across south-central and eastern Vermont, and across the
Adirondack high peaks. Gradual drying and developing partly
sunny skies are expected by Tuesday afternoon, along with breezy
conditions with west to northwesterly winds. High pressure will
then return for Tuesday night with patchy fog, followed by dry
and sunny conditions for Wednesday.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 955 PM EDT Monday...Forecast is playing out well. Light
precipitation barely reaching the surface across the Champlain
Valley, where deeper low-level moisture still has not quite
worked its way into the forecast area. This should quickly
change as lee side trough and cold front begin to interact over
the next few hours. Thus, continued to spend time refining the
PoPs. Wet bulb cooling from evaporative processes has brought
temps down quickly across Northern New York, and have refined
temps with latest hourly hi-res guidance and wet-bulb tools for
when it occurs across Vermont. Previous discussion below. Have
a great night.
Previous Discussion...
Finally seeing a breakdown of the mid-level ridging as upstream
shortwave trough migrates ewd across the Great Lakes region.
Meridional and increasingly cyclonic flow in advance of the
trough and PW values near 1.8-1.9" from BUF southward into the
upper Ohio valley, resulting in well-defined precipitation axes
across central/sern NY at 18Z, and also across Lake Erie and ern
Ohio very near the surface front position. Appears there will
be sufficient forcing for increasing clouds and developing rain
showers across St. Lawrence and Franklin counties by 21-22Z,
with rather sharp moisture gradient and resulting moisture
advection per 850mb RAP analyses. From the Champlain Valley ewd,
appears most of the precipitation will hold off until around
00Z this evening. PoPs at 23Z range from 21% at MPV, to 24% at
BTV, to 60% at SLK.
As we head through the overnight hours, will see upstream surface
cold front and best QG forcing moving from W-E across the North
Country. Expecting some periods of moderate rainfall given axis
of PW values between 1.8" and 1.9" translating ewd across the
North Country in advance of the bndry. Consistent with previous
runs, 12Z NWP modeling suite again not showing much in the way
of instability (saturated, moist neutral profiles), so will
continue to leave out any mention of thunderstorms with this
system. Total rainfall amounts generally 0.5" to locally around
1" with highest totals likely with best moisture advection into
the Adirondack high peaks and across south-central and eastern
VT. Fortunately, the frontal zone is progressive enough that we
will preclude any significant hydro threat; 6-hrly flash flood
guidance is generally 2-2.5", so we should be well below that in
terms of precipitation totals. Will see rain ending rather
quickly 11-15Z Tuesday morning as front shifts ewd into NH.
Gradual clearing and drying is expected through the day Tuesday.
Gradient flow is moderately strong from the W-NW, so looking
for winds 15-20 mph with some gusts 25-30 mph once sunny breaks
develop around mid-day. A Lake Wind Advisory may be needed for
Lake Champlain for the late morning through afternoon hours on
Tuesday. Surface high pressure builds in rapidly during Tuesday
night, allowing winds to diminish quickly around sunset. With
good radiational cooling conditions, appears favorable to reach
crossover temperatures. Also, moist soil conditions from the
rain early Tuesday will contribute to favorable conditions for
nocturnal fog development during Tuesday night. Have included
mention of patchy fog at this time for the favored valleys.
In terms of temperatures, lows tonight mainly 57-63F across the
Champlain Valley and central/ern VT, and in the 50s across nrn
NY with earlier passage of cold front. Will see moderate CAA
yield highs only in the 65-70F range for Tuesday afternoon, with
dewpoints again falling into the 40s. Cool and tranquil for
Tuesday night with lows 40-50F, coldest in Vermont`s Northeast
Kingdom and within the normally colder spots in the northern
Adirondacks.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 305 PM EDT Monday...Wednesday will be the nicest day of
the upcoming week with weak ridging aloft and a surface high
transiting the region. Subsidence associated with this feature
will help keep skies mostly clear through the day on Wednesday
with no chances for precipitation. Cloud cover will begin to
increase late Wednesday afternoon as the next storm system
begins to approach from the southwest but temperatures will
easily warm into the low to mid 70s region wide.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 305 PM EDT Monday...The forecast gets a little tricky on
Thursday as models still continue to struggle with the evolution
of the next storm system. The NAM/ECMWF/BTV4 all are pointing
at a weak surface low developing near Cape Cod on Thursday. The
GFS and Canadian show more of a surface trough and no closed
surface low. Regardless of the solution, however, it seems that
the main axis of moisture will shift well east of the area with
precipitable water values increasing to near an inch across the
North Country. Models continue to hint at a nice negatively
tilted trough swinging through on Thursday which supports good
upper level dynamics. This should help to increase PoPs to the
70% to 90% range by Thursday afternoon. With the moisture axis
well to the east, it looks like a widespread quarter to third of
an inch of rainfall will be possible but higher amounts seem
unlikely at this time due to the lack of instability and
moisture.
The front responsible for the rainfall will exit east on Friday
morning but the surface low will lag behind. As the low track
just north of the international border, some recycled maritime
air will wrap around the low and bring additional showers to
northern New York and northern Vermont. These showers should
exit the region by late Friday afternoon. However, unsettled
weather will continue through the weekend into next Monday as we
remain in fast zonal flow with a strong upper level low to our
north. Scattered showers will be possible through the weekend
but it doesn`t look like any particular day will be any wetter
than any other day. Temperatures will remain near normal with
highs in the mid 60s to mid 70s.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...Widespread light rain and MVFR
conditions expected overnight as frontal system passes through
the area. Initial VFR to lower to MVFR in the 02-06Z time frame
as steadier rains arrive under light south to southeast flow
generally less than 10 kts. Rains taper off west to east in the
09-14Z time frame as front clears east. Occnl IFR possible at
KSLK during this period and possibly at KMSS/KMPV but confidence
lower at these latter terminals. MVFR lifts to VFR at all
terminals in the 14 to 18Z time frame with post-frontal winds
shifting to west/northwesterly 8-14 kts and occasionally gusty
to 20 kts.
Outlook...
Tuesday Night: VFR. Patchy BR.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Chance SHRA.
Thursday Night: Mainly VFR, with areas MVFR possible. Chance
SHRA.
Friday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Friday Night: VFR. Chance SHRA.
Saturday: Mainly VFR, with local MVFR possible. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Banacos
NEAR TERM...Banacos/Haynes
SHORT TERM...Clay
LONG TERM...Clay
AVIATION...JMG
Area Forecast Discussion
National Weather Service State College PA
1132 PM EDT Mon Jun 10 2019
.SYNOPSIS...
A cold front moving through now will clear the region shortly.
Dry conditions with seasonable temperatures will return for
Tuesday and Wednesday. More wet weather will be possible later
in the week, as another strong cold front moves across the
region.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
Cold front through the wrn counties and wind gusting into the
20s there. Not much fanfare as these showers come through.
Nobody has even picked up 0.5" of rain at the METARs to the west
of I-99. Current fcst timing pretty good for ending of showers,
perhaps just a hour or two too slow. But, some parallel banded
showers dropping into the Laurels at this time.
Prev...
Lightning dropping off as the line of showers assocd with the
cold front is nearing the CWA. Meager CAPE still avbl, and RAP
still paints >1000J over SWrn PA. Gusts with the front seem to
be under 30kts. The threat of flooding has diminished as well,
with the showers moving steadily and few spots of >1" of precip
over wrn PA. Refined timing of precip entry/exit using recent
CAMs as they seem to have a decent handle on the current
location and forward speed.
Prev...
A chilly damp day is in progress over the CWA with clouds and
periods of light rain and drizzle. The guidance suggests we will
maintain the warm season cool-air damming scenario into the
evening hours, with temperatures likely holding fairly steady
unto the cold front passes and we start to see cooler and drier
air advect into the area after midnight.
The various flavors of the HREF agree in marching an area of
more organized showers across the forecast area between about
5PM and 2AM. Lifted indices are forecast to fall to below zero
along and just ahead of the frontal trough, so there is the
mention of a chance of thunder. However with the falling sun and
the cool air damming, CAPE is forecast to dwindle rapidly as
the convection enters the central counties. Regardless, there
could be a few embedded heavier short-lived downpours with the
fairly sharp frontal boundary. Cell movement will be rather fast
and that combined with the recent extended stretch of dry
weather will limit the threat of flash flooding.
Showers will diminish from west to east during the middle of
tonight as a cold front sweeps across central PA.
Temps will dip to lows in the upper 40s across our far NW zones
and ridgetops of the Laurels early Tuesday, and settle into the
50s to lower 60s elsewhere.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Tuesday will be bright and breezy with very comfortable
humidity. A gusty NW wind of 15-25mph will make it feel a tad
chillier than the 5-10 deg below normal that it will end up
being.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Winds will slacken Tuesday night and skies will clear out as
the center of high pressure drifts overhead.
A progressive upper pattern will bring several chances for
showers/thunderstorms during the long term period. A front will
brings a renewed chance for showers Thursday into Friday. At
this point, dry weather pushes into the area next weekend.
Another frontal system, a bit ill defined at this point will
approach late in the weekend into next Monday.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
A frontal boundary will cross the Susquehanna Valley during the
early overnight hours, accompanied by rain showers. Behind the
front, the showers will end and winds will shift to the west-
northwest and become a bit gusty. The west-northwest flow should
maintain low cigs over the western high terrain /KBFD and KJST/.
A breezy west-northwest wind will continue into Tuesday.
Reduced cigs across the west will improve during the morning
hours, with VFR conds elsewhere.
.Outlook...
Wed...Patchy AM fog possible. Otherwise VFR.
Wed night-Thu...AM rain/low cigs possible. PM showers/t-storms.
Fri...Isolated showers possible over northern tier.
Sat...Mainly VFR, with PM showers possible west.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...Dangelo/La Corte
SHORT TERM...La Corte
LONG TERM...Lambert/Gartner
AVIATION...Evanego
Area Forecast Discussion
National Weather Service Miami FL
757 PM EDT Mon Jun 10 2019
.UPDATE...
Convection was able to fire , mainly due to outflow boundaries
from Central Florida and a weak sea breeze boundary moving north
from the southern tip of Florida. Storms are generally isolated at
this time, except for near the Lake. However, these storms are
beginning to move out of the area at this time. However, still can
not rule out any other convective initiation this evening, at
least for another couple of hours. Models indicate tonight
convection should diminish, with a slight chance in the eastern
interior for some showers through late this evening.
&&
.PREV DISCUSSION... /issued 734 PM EDT Mon Jun 10 2019/
AVIATION...
Scattered SHRA/TSRA should continue this evening, potentially
impacting the eastern terminals with brief sub-VFR conditions.
VCSH returns later tonight with VCTS possible by morning, but more
likely during the afternoon. Light winds overnight with southerly
flow developing tomorrow afternoon. Kept the eastern TAF sites
mostly SSE, but a period of SSW is possible during the
afternoon/evening as well.
PREV DISCUSSION... /issued 322 PM EDT Mon Jun 10 2019/
DISCUSSION...
Today has been quieter than the last couple of days, mainly due to
a debris cloud cover that has kept temperatures cooler than if
there was more insolation. However, the cloud cover is thinning,
and temperatures are climbing this afternoon, and may be enough to
allow some initiation of convection over South Florida. The HRRR
shows a few convective cells through the evening hours, but not
very much coverage. Given this uncertainty, have kept a chance of
showers and thunderstorms.
Tonight and tomorrow, models are indicating a drier air mass will
move across the area, dropping PWATs to around 1.5 inches, maybe
slightly lower. However, PWATs do seem to creep back up over the
eastern half of the CWA. Given this, have kept chance PoPs and a
chance of thunder for mainly tomorrow afternoon and evening.
Convection may be aided by the 500mb trough finally progressing
eastward as a very weak short wave, ahead of a more vigorous 500
mb trough digging over the central US.
After tomorrow, PWATs climb back to around 2 inches each
afternoon, along with temperatures in the 90s each day. Also, the
500mb trough is slow to progress across the eastern US, allowing
for additional favorable dynamics for the latter half of the week.
Models indicate a surface low developing, with a cold front moving
further south than previously showing in the models, but still
stalls over Central Florida. This would provide even more
instability, and if the front get closer, it will just increase
chances of showers and storms.
By the weekend, high pressure builds well to the north, bringing
the easterly flow back to South Florida for the weekend. This will
allow for the Atlantic sea breeze to dominate. This means
convective initialization will probably occur along the Atlantic
coast, as the sea breeze develops, then progress to the interior
and then to the Gulf coast.
So, in summary, wet season is here, and daily showers and
thunderstorms are in the forecast. It will be more daily
mesoscale features that will be the ultimate trigger for
convection as well as where and when.
MARINE...
No significant marine concerns through the week, with seas
generally running up to 2 feet. Showers and thunderstorms will
continue to be possible through the weekend, which may bring
locally hazardous marine conditions.
AVIATION...
The short range models are still showing the development of
SHRA and TS over the east coast TAF sites this afternoon.
Therefore, VCTS will continue over the east coast taf sites
through 00Z. The weather should then dry out tonight over the east
coast taf sites, with VCSH after 06Z for KAPF TAF site. the
ceiling and vis will remain in VFR condition, but could drop into
MVFR or even IFR conditions with the passage of the showers and
thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 76 88 76 90 / 20 30 30 50
Fort Lauderdale 78 87 78 89 / 20 20 20 40
Miami 78 88 78 90 / 20 20 20 40
Naples 77 88 77 90 / 10 10 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...13
DISCUSSION...13
MARINE...13
AVIATION...34/SPM