Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/20/17
Area Forecast Discussion
National Weather Service Albany NY
757 PM EDT Mon Jun 19 2017
.SYNOPSIS...
A cold front will bring showers, some with heavy rain, and the
possibility of an isolated thunderstorm through this evening.
Breezy and less humid conditions are forecast for Tuesday and
Wednesday, with a chance of afternoon showers and possibly a
thunderstorm.
&&
.NEAR TERM /THROUGH TUESDAY/...
A Flash Flood Watch remains in effect for western New England
through 4AM...
Severe Thunderstorm Watch #354 has been cancelled.
As of 716 PM...Heaviest precipitation has mainly moved east of
the Albany Forecast Area. Some heavier showers linger over
southern Litchfield County. Additional areas of rain on radar
mainly east of the hudson River.
Rain has cooled temperatures this evening so updated diurnal
temperature curve. With small temperature/dewpoint spreads
across the area, fog formation is still expected overnight.
Latest HRRR model run shows some isolated to scattered showers
overnight. Kept mention of showers and slight chance thunder in
grids overnight.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Showers and storms will continue tonight ahead of the cold
front as it crosses the Albany Forecast Area. Some areas will
see very heavy downpours with the warm and wet airmass in place.
Models indicate the cold front will be east of our area by 8AM
Tuesday. With the wet ground and light winds, expect patchy fog
to develop overnight. Lows tonight in the 50s and 60s.
A drier westerly flow is expected on Tuesday, although cyclonic
flow will continue across the area. Model RH fields show some
clearing should develop tomorrow morning after patchy fog burns
off, and before the suns heating warms the atmosphere to the
convective temperature. Soundings show 2-300 J/KG of cape
Tuesday afternoon which means there could be some isolated
showers and thunderstorms. Highs on Tuesday generally from the
mid 70s to mid 80s.
Cool cyclonic flow continues Tuesday night. An upper level shortwave
may move across the area in the cyclonic flow so a shower can`t
be ruled out. Lows mainly in the 50s.
High pressure build into the area for Wednesday into Thursday.
Generally fair and seasonable weather is forecast on Wednesday
with highs around 70 in the northwest to around 80 far south.
Wednesday night looks to be fair and cool with lows mainly in
the 50s with some 40s in the normally cooler locations. Thursday
begins fair, but clouds look to increase ahead of a low
pressure system moving across the Great Lakes. Increased threat
of showers late in the day over the southern Adirondacks. Highs
forecast in the 70s to around 80.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The long term period will be active with at/above average
temperatures and multiple systems moving through the region.
Above normal temperatures and more humid conditions look to be in
store for Friday, as our region should be in the warm sector in wake
of the warm front passage. The GFS actually indicating the tropical
entity currently in the Gulf of Mexico getting caught up in the
southwest flow aloft and moving through our area on Friday. Will
discount this solution for now, as the ECMWF and CMC are not similar
with handling the potential tropical system, suppressing it well to
our south. A cold front passage and associated showers and
thunderstorms appear more likely, with a relatively zonal flow
aloft.
Showers and thunderstorms could linger into Saturday night depending
on the timing of the cold front passage. Conditions will be warm and
humid before the passage of the front then cool off and dry out late
Saturday heading into Sunday. The next system then approaches from
the Midwest and Great Lakes on Sunday, bringing another round of
possible showers and thunderstorms to close out the weekend.
A quick system looks to move through the region Monday bringing yet
another chance for showers before strong high pressure begins to
build in for the the beginning/middle of next week.
Overall, a relatively unsettled pattern continues with temperatures
near to slightly above normal.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
The airmass over the local area has been convectively overturned
and has become stable. The threat for heavy rainfall and severe
thunderstorms has ended. However, with the cold front still off
to the west, we could have some additional showers or perhaps a
thunderstorm to contend with overnight. This potential is too
low to include in the TAFs, but will continue to monitor.
Otherwise, mainly cloudy conditions exist currently, with
varying cloud bases. Conditions are VFR at all sites except
KPSF, but expect cigs to lower overnight into the MVFR and
perhaps IFR range. There is an area of clearing working into
south-central New York, but it is unclear if it will make it
into the local terminals. Regardless, some reduction in
visibility is likely overnight, but this potential would
increase were clearing of the low and mid-level clouds to work
into the local area. Will trend vsby down in concert with cigs
to MVFR/IFR overnight.
A quick improvement in aviation conditions is expected shortly
after sunrise Tuesday in the wake of the frontal passage. A
shower or two cannot be ruled out, but due to the dry incoming
airmass, potential should be too low to include in the TAFs.
Winds overnight will be light out of the south. Winds after
sunrise Tuesday will become southwesterly at 10 to 15 kt with
some gusts of 20 to 25 kt possible during the late morning into
the afternoon.
Outlook...
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: High Operational Impact. Likely SHRA...TSRA.
Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Saturday: Moderate Operational Impact. Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
More widespread rainfall, heavy at times, along with strong to
severe thunderstorms are expected through this evening, as a
slow moving cold front gradually pushes east across the region.
On Tuesday there will still be a chance of showers, but overall,
breezy, less humid conditions are forecast.
Relative humidity values will recover to 90 to 100 percent
tonight, drop to 40 to 60 percent on Tuesday and recover to 90
to 100 percent again by Wednesday morning.
Winds today into this evening will be southerly at around 15
mph but some gusts to 25 mph are possible in the afternoon.
Winds could gust over 40 mph in thunderstorms. Southwest winds at
15 mph or less are expected tonight and west at around 15 mph
on Tuesday.
&&
.HYDROLOGY...
A Flash Flood Watch is in effect for most of eastern New York
and western New England, except for the western Adirondacks,
through much of Monday night.
Widespread showers and thunderstorms with downpours are
expected ahead of a cold front this evening into tonight.
downpours from thunderstorms could lead to some flash flooding
where heavy rainfall is most persistent and/or where thunderstorms
repeatedly move across the same areas. Many areas will see 1 to
2 inches of rain but localized rainfall could be 2 to 4 inches.
Urban and poor drainage flooding is expected. Some smaller
streams could also see rises to near flood levels where larger
areas of heavy rain saturate entire small basins.
Scattered showers and isolated thunderstorms are in the
forecast for Tuesday and Wednesday, mainly in the afternoon both
days, although rainfall should be much lighter than today so no
additional hydro issues are anticipated.
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.
&&
.EQUIPMENT...
KGFL airport observation continues to experience intermittent
communication issues. In addition, both the initial and second
release for this morning`s 12Z KALY sounding was short due to
loss of signal.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Flash Flood Watch until 4 AM EDT Tuesday for CTZ001-013.
NY...None.
MA...Flash Flood Watch until 4 AM EDT Tuesday for MAZ001-025.
VT...Flash Flood Watch until 4 AM EDT Tuesday for VTZ013>015.
&&
$$
SYNOPSIS...SND
NEAR TERM...SND
SHORT TERM...SND
LONG TERM...Cebulko
AVIATION...Thompson
FIRE WEATHER...SND
HYDROLOGY...SND
EQUIPMENT...
Area Forecast Discussion
National Weather Service Bismarck ND
903 PM CDT Mon Jun 19 2017
.UPDATE...
Issued at 903 PM CDT Mon Jun 19 2017
The bulk of the showers and thunderstorms have moved east of the
forecast area. The HRRR still suggests the potential for a shower
along and east of a line from Fessenden to Jamestown for another
hour or two, with mainly dry weather overnight as surface high
pressure builds into the region. Updated to diminish rain chances,
and blend in current conditions. The remainder of the forecast
remains on track.
UPDATE Issued at 701 PM CDT Mon Jun 19 2017
Regional radar mosaic shows showers and thunderstorms moving
southeast through Stutsman county and a few across southern Canada
heading towards northern Rolette county. The storms have been
producing 40 mph at times, and that threat continues for another
couple hours until the stronger forcing shifts a bit more to the
east. The latest HRRR lingers a few showers until 10 or 11 pm, but
those should be fairly isolated.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 147 PM CDT Mon Jun 19 2017
The risk of strong to severe thunderstorms from north central ND
into the James River Valley this afternoon will be replaced with
cool overnight temperatures and a day with light winds Tuesday.
As of 1845 UTC, low-topped convection is intensifying across far
southern Canada ahead of a strong mid-level vorticity maximum
that is forecast to reach northeast ND by early evening. Forcing
for ascent from resultant DCVA aloft and in association with a
southeast-moving surface cold frontal zone is still expected to
drive rapidly-southeastward-moving thunderstorms this afternoon.
Forecast and RAP-objectively-analyzed soundings still support a
weakly buoyant air mass with MLCAPE up to 500 J/kg, but intense
deep-layer wind fields are yielding 0-6-km bulk wind differences
of 60 to 70 kt in support of an organized, low CAPE, high shear
convective situation. CAMs through the 17 UTC HRRR and 15 UTC ESRL
HRRR remain in strong agreement with their support of potentially
severe convection with maximum updraft helicity tracks of 50 to
75 m2/s2 in the 20 to 00 UTC time range, especially in north
central ND where brief supercell structures may be favored before
upscale growth into a line perhaps occurs with expanding cold
pools. The high-based nature of the convection related to the
relatively dry boundary layer will favor evaporational cooling and
thus enhanced downdrafts, and the strong environmental winds will
favor strong momentum transfer, both in support of potentially
damaging wind gusts at the surface. The cold temperatures aloft
and strongly-tilted updrafts suggest potential for marginally-
severe hailstones with the most intense cores, as well, though
HAILCAST output from the 00 and 12 UTC NSSL WRF-ARW was very
unimpressive with peak model hail sizes less than an inch.
We expect convection to rapidly shift southeast of the area by
about 01 UTC. Surface high pressure will follow the cold front
into the area overnight and is expected to be in control of the
weather during the time of optimum radiational cooling prior to
sunrise. Given observed temperatures upstream in Canada beneath
that ridge axis and the tendency for guidance to underestimate
radiational cooling in these scenarios, we relied on the coldest
edge of 12 UTC model guidance for forecast lows tonight. Thus, we
are advertising widespread lows in the lower to middle 40s F.
The proximity of the surface ridge will ensure light winds for
once on Tuesday, while building heights aloft will yield a dry
day, with forecast highs from the 70s F in the James River Valley
to the mid 80s in southwest ND where southerly return flow and
warm advection will take hold by afternoon.
.LONG TERM...(Tuesday night through Monday)
Issued at 147 PM CDT Mon Jun 19 2017
Very cool, below-normal temperatures from late this week through
the weekend highlight the long term forecast period.
Based on the 00 and 12 UTC global models, our confidence remains
high that a mean 500 mb trough will develop over the region by
Friday in response to an upstream ridge building across British
Columbia. The transition from initially-zonal flow aloft will be
heralded by a dynamic shortwave trough and surface cold frontal
passage Wednesday afternoon. Mid-level warm air advection on the
nose of a 35-45 kt low-level jet in advance of that shortwave may
yield some elevated convection Tuesday night and Wednesday. Model-
derived soundings suggest enough MUCAPE in the face of steepening
mid-level lapse rates associated with a pulse of elevated mixed
layer air spreading across the northern Plains to support a few
thunderstorms in that batch of elevated convection. Any chance of
stronger, surface-based thunderstorms on Wednesday afternoon is a
topic of much lower confidence owing to uncertainty with both the
potential for early-day convection to slow destabilization, and a
more real possibility that the surface cold front will have moved
east of the local area by the time that wind shift is able to act
upon the destabilizing boundary layer. True to that point, the 12
UTC GFS has the front into the Red River Valley by the time that
occurs, while the 12 UTC NAM simulates a slow enough passage to
allow for afternoon storms in the James River Valley. We are more
certain that gusty northwest winds will likely follow that front,
in the west Wednesday, and area-wide on Thursday.
By Friday and Saturday, the 00 UTC NAEFS calls for temperatures
at 850 mb falling to the 4 to 8 C range underneath the trough,
which is near the 10th percentile of those temperatures for this
time of the year. The 00 UTC CIPS Analog guidance not only calls
for a 95 percent probability of below-normal temperatures for the
weekend, but its actual analog dates (most of which were from May
and early June) only had highs greater than 70 F in roughly 30
percent of the cases. The opportunity for precipitation in that
time is less certain, with the 00 UTC ECMWF slower and stronger
with a shortwave trough and thus wetter than both the 12 and 00
UTC GFS runs. The GFS ensemble plumes suggest wide spread in the
possibility of precipitation, as well, but it`s worth noting that
the 12 UTC GFS did indeed take a step toward the wetter side of
solutions, albeit with a faster wave timing than the ECMWF.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 903 PM CDT Mon Jun 19 2017
VFR conditions are expected as surface high pressure builds into
the region. The best chances of thunderstorms have moved east of
the aerodromes.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...CK
Area Forecast Discussion
National Weather Service Green Bay WI
1037 PM CDT Mon Jun 19 2017
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Tuesday
Issued at 226 PM CDT Mon Jun 19 2017
The latest rap analysis and satellite/radar imagery show deep layer
cyclonic flow across the western Great Lakes region. Several
shortwaves within this cyclonic flow are interacting with daytime
instability (sb capes > 1000 j/kg over eastern WI) to produce
numerous showers and scattered thunderstorms. Highest coverage of
showers and storms should occur over eastern WI for the rest of the
afternoon. Not out of the question any storms could produce small
hail, brief gusty winds, and even funnel cloud given high non-
supercell tornado parameter. The next shortwave is located over
Saskatchewan and poised to arrive early tomorrow morning. Precip
trends are the main forecast concern in the short term.
Tonight...Upper troughing will remain firmly in place over the
region. Scattered showers will likely persist into the evening but
coverage/intensity should gradually diminish with loss of heating.
Still though, coverage should be highest over eastern WI this
evening, where a few thunderstorms will likely persist. Once the
showers have ended, should see quiet conditions for a several hour
period under scattered to broken clouds. Then clouds will be on the
increase late tonight as a potent shortwave over Saskatchewan moves
towards the region. This shortwave will generate a chance of
showers by 7am over central and north-central WI. Low temps ranging
from the upper 40s north to mid 50s south.
Tuesday...The shortwave will track across the region during the
morning before exiting in the afternoon. The higher resolution
models place the highest qpf over central and east-central WI, where
the best forcing via mid-level fgen/upper divergence and also
instability will reside. With capes of 200-400 j/kg, a few
thunderstorms could also accompany the shortwave. As the shortwave
and associated precip exits, isolated to scattered showers could
persist through the end of the afternoon. Highs ranging from the
mid 60s north to low 70s south.
.LONG TERM...Tuesday Night Through Monday
Issued at 226 PM CDT Mon Jun 19 2017
The next chance of rain and the focus of this part of the
forecast will be toward Wednesday evening into Thursday.
A few stray showers may linger Tuesday evening over eastern
Wisconsin as a short wave trough departs the area. Otherwise a
surface high pressure ridge will drift over the western Great
Lakes late Tuesday into Wednesday as upper heights increase and
the flow aloft goes from a northwest flow regime to a zonal flow.
A brief quiet stretch of weather is the result.
The the next frontal system will approach from the northern
plains Wednesday afternoon or Wednesday evening, followed with a
cold frontal passage toward Thursday morning. Progs have slowed
down the timing of arrival starting Wednesday evening. A period of
PWATS climbing to 1.75 inches along and ahead of the cold front
will potentially produce up to an inch of widespread rain in the
24 hour period.
The slow down of the frontal system may delay the departure of
the precipitation from northwest to southeast on Thursday. Progs
are consistent with dropping the cold front south of the area by
noon Thursday for brief trend toward drier conditions for at least
northern wisconsin. A few showers may linger over parts of
central and east central Wisconsin Thursday into Thursday night
closer to the cold front, or mainly south of highway 10. Will keep
a dry forecast going friday as drier air continues to settle
southward.
Consensus of the medium range progs transition to a broad upper
trough dropping into the Northern and Central Plains this
weekend. A southwest flow aloft over the Great Lakes will allow
a moist air mass to settle into the area with a return of more
precipitation. Max temperatures will depend on amount of clouds,
but appears cooler than normal this weekend.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1036 PM CDT Mon Jun 19 2017
Showers have diminished with the loss of heating. A strong
shortwave dropping southeast into the region will bring another
round of showers to the area late tonight into Tuesday. The
strongest forcing is likely to pass southwest of the area, but
there should still be enough forcing for another round of at least
scattered showers.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Gray ME
1042 PM EDT Mon Jun 19 2017
.SYNOPSIS...
A warm and very humid airmass will remain across the region
through Tuesday. A cold front approaching from the Great
Lakes Region will bring widespread shower and thunderstorm
activity to the region through tonight. Some of the
thunderstorms could produce damaging winds and torrential
downpours into this evening. On Tuesday, the cold front will
gradually weaken as it slides offshore. The next weak trough
will move across the area on Wednesday producing a few showers
mainly in the mountains and foothills. The next more significant
system approaches late Thursday into Friday bringing a return
to unsettled weather.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1045 pm Update...
Have updated the grids based on current conditions and radar
imagery. Showers continue to move east and weaken. Will still
include a slight chance of a thunderstorm for the next few
hours, however this will be limited in scope and area.
Areas of fog will be developing shortly as temperatures are
very close to their dew point values.
Adjusted mins to reflect readings close to current
temperatures.
805 pm Update: The Severe thunderstorm watch #355 has expired
and we have also cancelled the flood watch across the CWA. Have
made adjustments to grids to reflect the diminishing convection.
Some areas of convection continues across the area but the
heaviest precipitation is over as the convection will continue
to wane and become scattered over the next few hours as per the
HRRR suggests. Downpours still possible in some of the
convection the rest of the night but training of lighter showers
will have no impact.
Previous Discussion:
The tropical air mass will remain in place through tonight
ahead of the approaching cold front so widespread showers and
scattered thunderstorms are expected to continue. The severe
thunderstorm watch will remain in effect until 8 pm tonight. The
primary threat with the severe thunderstorm watch is due to
potentially damaging winds.
With very high PWATS exceeding 200 percent of normal torrential
downpours are likely. Some lines of convection will occur and
may produce a training effect, this may cause some flash
flooding so the Flash Flood will remain in effect until 8 am Tue
morning.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Tue morning the front slowly moves across the area and then off
the coast. This will bring an end to the showers except in the
mountains where some will linger. Surface temps will be very
warm as h85 temps aloft remain around +12C. This will mean highs
should reach into the 80s over most areas.
Tue night a drier westerly flow will develop lowering the
dewpoints and temps. Overnight lows should be in the 50s.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Looks like an activer period with a front/surface low moving
through every few days. For Wednesday a cold front will move
through Wednesday morning with showers and possible
thunderstorms. High pressure builds in for Thursday but the next
front will be arriving Friday first with a warm front moving
through followed by the cold front Friday night. Expect likely
POPS with showers and thunderstorms. The ECMWF moves the front
through Saturday morning but the GFS forms a surface wave on the
front which delays the progress of the front with the front
moving through Sunday morning. Another cold front or trough
moves through Monday afternoon.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Short Term...Tonight variable conditions in showers and
thunderstorms. Some storms may contain high winds into this
evening. MVFR to IFR conditions will occur in the areas of
convection otherwise VFR.
Tue - conditions become VFR behind the exiting frontal passage
by later in the morning and afternoon.
Tue night...VFR.
Long Term...Expect MVFR?IFR in showers and thunderstorms
Wednesday. VFR Thursday. MVFR/IFR returns for Friday afternoon
with conditions lingering into Saturday and possibly Sunday.
&&
.MARINE...
Short Term...SCA conditions will continue tonight into Tue in
a persistent Sly flow. There will be some gusts above 25
kts. Seas will be mainly above 5 ft mainly outside of the bays.
By late Tue and Tue night the winds will shift to the west and
seas will slowly subside. An SCA for just seas will likely be
needed over just the outer waters late Tue into Tue night.
Long Term...SCA possible Friday and Saturday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ150>154.
&&
$$
JC
Area Forecast Discussion
National Weather Service Wilmington NC
921 PM EDT Mon Jun 19 2017
.SYNOPSIS...
Bermuda high pressure will remain centered offshore this week,
but will continue to ridge back to the west, and onshore and
inland in the vicinity of Cape Romain. A cold front will drop
southward tonight and stall just inland from the coast on Tue
before dissipating altogether by Wednesday. Tropical moisture
will funnel northward from the Gulf of Mexico for much of this
week, further enhancing the convection across the area thruout
this week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 900 PM Monday...Much of the ILM CWA has been worked over
by the earlier convection. As a result, will see a brief
reprieve in the convection for the remainder of this evening
and thru the pre-dawn Tue hrs. The exception will be the
coastal counties within the ILM CWA where convective activity
will develop over the adjacent Atl Waters and then push north
by northeast and likely either push onshore or side-swipe the
ILM Coasts. Have upped POPs to a solid 50 for the immediate
coast. Near term models ie. HRRR and HIRESW indicate the cold
front to drop SSE closer to the ILM CWA overnight with
convection still firing along it. Thus activity from the south
and from the north will come together over the ILM CWA during
daylight Tuesday with POPS either good chance or likely. Mid-
level vorticies ie. sheared vort, sfc cold front, resultant wind
bndry aka sea breeze and outflow boundaries, will all become
players in keeping convection ignited across the ILM CWA. PWS
are progged to run greater than 2 inches. Thus looking at heavy
rains producing localized flooding. Will have to look at 00Z
model runs and see if the potential is there for precip loading
to occur with an end result in a wet microburst. Will update
the HWO and indicate the local flood potential.
Previous......................................................
As of 245 PM Monday...Sea breeze and Bermuda High convergence
is shifting the storm focus farther inland this afternoon.
GOES-16 low- level water vapor shows the mid-level cap well
inland is beginning to erode from WSW to ENE this afternoon and
may allow for storms to become more numerous along the I-95
corridor into mid/late afternoon. Untapped air and larger
downdraft CAPES in this area could lead to stronger storms in
the hours ahead.
Active period through Tuesday, as an upper trough trough
slowly translates east toward the area coupled with a feed of
tropical moisture. PW values will climb a bit more and exceed 2
inches. Low-levels winds not very strong Tuesday so the primary
threat looks to be localized flooding, as storms drop tropical
moisture while exhibiting sluggish storm motion.
As buoyancy increases tonight over the waters, scattered deep
convection should develop late tonight into very early
Tuesday, and a portion of this may get directed onshore into
the coast. Meanwhile, upper support will increase well inland
as the trough aloft nears, so most places will have a shot at
rain overnight.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
As of 3 PM Monday...Front stalled west of the area at the start
of the period will gradually dissipate Tue night and Wed.
Although the surface boundary will be ill defined there will be
an abundance of deep moisture moving into the area as the 5h
trough taps into moisture plume associated with the Gulf of
Mexico system. Currently it appears that the system will not
have a direct impact on the region during the period. However,
there is some uncertainty with respect to how much moisture
spreads over the Southeast and how long the moisture lingers.
The GFS has a huge plume of moisture spreading over the area Tue
night and lingering through the end of the period. The Canadian
and ECMWF has a toned down version of the tropical plume and
have the moisture shifting east during Wed with decreasing
precip chances late Wed and Wed night. Precipitable water values
climb above 2 inches Tue night as the plume arrives but forcing
may be limited, outside of already ongoing diurnal convection
from Tue afternoon and evening. The odd shortwave rotating
around the base of the 5h trough could help light off convection
but the best shot may be with diurnal heating Wed, provided the
tropical moisture hangs around into peak heating. Low
temperatures will run well above climo while highs on Wed will
be held below climo by cloud cover and rainfall.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 300 PM Monday...Unsettled weather with a chance for
showers and thunderstorms is expected through the extended
period though chances for showers and thunderstorms will
diminish a little Friday and Saturday as upper ridge builds west
into the area. Upper troughing will return for Sunday and
Monday resulting in increasing chances for showers and
thunderstorms again. High temperatures will increase from the
mid to upper 80s thursday to the upper 80s to lower 90s for the
weekend before moderating slightly to the mid to upper 80s for
Monday. Lows should be in the low to mid 70s through the period.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 00Z...Brief reprieve in the pcpn action along the
immediate coast this evening into the pre-dawn Tue hrs. For the
inland terminals, convection will occur just beyond 25 nm from
the inland terminals. May indicate VCTS for those inland
terminals to account for the relatively closeness of the
thunder. The near term models, HRRR, RAPS and HIRESW do not
agree with one another with respect to the placement and
movement of the current convection as well as down the line.
Tstrm parameters, specifically instability, remains avbl all
night long and into daytime Tue. Mid-level vorts, somewhat
sheared, are progged to move across the Eastern Carolinas mainly
during the daylight hours of Tue. As a result, will ramp up the
convection for all locations and have it become the prevailing
condition across all terminals by late Tue morning or early Tue
aftn. Winds will slightly back from 180 degrees to around 230
degrees by daybreak Tue...followed by a slow veering trend back
to 180-200 degrees during Tue aftn. With PWs over 2 inches,
heavy rain will dominate the convection, enough to briefly
lower vsby to 2sm or less at times.
Extended Outlook...The risk for flight restrictions due to
thunderstorms will continue through the period. The probability
for reduced ceilings and visibility in thunderstorms with heavy
rain should be highest Tue night through Wed and possibly again
on Fri.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 900 PM Monday...SCEC to continue across the local waters.
Ridging from the center of high pressure well offshore and
east of Cape Hatters will extend westward and inland just south
of Cape Romain tonight thru Tue. The sfc pg will be at its
tightest tonight then slightly relax during Tue as a result of
the cold front having dropped south and becoming stalled just
inland and north of the local waters. As a result, the SW wind
direction will persist. Wind speeds in the 15 to 20 kt range
will diminish to around 15 kt or 10-15 kt during Tue.
Significant seas will initially run 3 to 5 ft and only lower
to 2 to 4 ft during Tue. Wind driven waves at 6 second periods
will dominate the seas spectrum. A 1 to 2 foot SE-SSE ground
swell at 13 to 15 second periods will remain in the background.
Previous........................................................
As of 245 PM Monday...An `Exercise Caution` headline was needed
to account for seas up to 5 feet offshore and widespread 20 KT
SW winds remainder of this afternoon and overnight. TSTMS will
also increase overnight, leading to localized strong winds in
and near convection. Spectral data indicates see energy is
dominated by SSW waves in 5-6 second wave periods, with fading
long period east swell. Mariners are encouraged to obtain a
radar update before heading out this evening and overnight as
a few robust storms are expected to move onshore late tonight.
Seas 3-4 feet near shore will remain bumpy through tonight as
winds remain elevated.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 3 PM Monday...Bermuda High will maintain southwest flow
through the period with speeds peaking on the high end of the
10 to 15 kt range late Wed afternoon and evening. Seas will
run around 3 ft through the period with an occasional 4 ft
creeping in late in the period.
LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 300 PM Monday...South to southwest winds of 10 to 15 kt
are expected through the period with seas of 2 to 4 ft. Winds
and seas may run higher in scattered thunderstorms.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...DCH
NEAR TERM...DCH/MJC
SHORT TERM...III
LONG TERM...RAN
AVIATION...DCH
Area Forecast Discussion
National Weather Service Indianapolis IN
950 PM EDT Mon Jun 19 2017
.UPDATE...
The Near Term section has been updated below.
&&
.SYNOPSIS...
Issued at 309 PM EDT Mon Jun 19 2017
Upper troughing will continue to keep temperatures a bit
suppressed for the next couple of days before upper ridging
arrives to bring more warmth. This trough will also keep some low
chances for showers and thunderstorms in the forecast for this
afternoon into early tonight for parts of the area and then again
tomorrow afternoon. After that the upper ridging should provide
mainly dry weather until Thursday evening. At that point models
show a more active pattern moving back in, with chances for
showers and thunderstorms through much of the weekend.
&&
.NEAR TERM /This Evening and Tonight/...
Issued at 950 PM EDT Mon Jun 19 2017
Minor adjustments made to pop grids for persistent showers/embedded
thunder that will likely make it into the area before dissipating
later this evening. Previous discussion follows.
Issued at 309 PM EDT Mon Jun 19 2017
High res guidance for the remainder of the afternoon into evening
continues to show scattered showers and storms across the
north/northeast forecast moving eastward with time. Some
disagreement on when this will come to an end, with the HRRR
moving it all out by 0z and then showing a smaller area of showers
moving into the southwestern counties in the 1-5z timeframe
before becoming dry. The RAP and NAM keep some qpf running across
the north/northeast counties until 3z or so. Plan will be to keep
at least a slight chance for showers/storms going 0-3z across the
north/northeastern counties and go dry elsewhere.
After 3z will be going dry for the remainder of the night with
lack of forcing or instability. Should see mostly clear skies to
the southwest under the influence of the surface high.
For low temperatures, went with a bias corrected consensus.
&&
.SHORT TERM /Tuesday through Thursday/...
Issued at 309 PM EDT Mon Jun 19 2017
Another spoke of upper energy will move through the area late
Tuesday afternoon into Tuesday night. The upper wave will move in
from the northwest and could have a weak surface front moving
through as well. With a surface high still to the south/southeast
of the area, will carry some pops in the northern part of the
forecast area but not extend those from there given the more
subsident and stable atmosphere to the southeast.
Wednesday into Wednesday night there is some model disagreement
with PoPs, with the operational NAM much more aggressive with qpf.
MOS guidance is trending drier with the MAV and wetter with the
MET. Given the upper pattern shows upper ridging sliding through
the area Wednesday into Thursday, will stick with the dry PoPs
from the intialization. Given the solution variability though the
dry forecast for Wednesday through Thursday is only low to medium
confidence at best. Higher confidence of a warming trend during
the short term.
&&
.LONG TERM /Thursday Night through Monday/...
Issued at 240 PM EDT Mon Jun 19 2017
Active weather will occur Friday as a cold front moves southeast
across our region. There will be lots of moisture as a tropical
system moves into the lower Mississippi valley and then northeast
across Tennessee and Kentucky. Models indicate a cold front
will stall across southern Indiana Saturday and then moving
southeast Sunday and Monday as high pressure over the central
plains builds eastward early next week.
There is lots of uncertainty on rain chances over the weekend as
the Canadian is mostly dry...while the GFS is mostly dry Saturday
and somewhat wet Sunday. Will carry low chance POPS some areas
over the weekend and then dry all areas Sunday night and Monday
as high pressure over the plains builds our way.
Temperatures will be near normal Friday into Saturday and below
normal early next week. In most cases stayed close to model
initialized temperatures.
&&
.AVIATION /Discussion for the 20/00Z TAFs/...
Issued at 732 PM EDT Mon Jun 19 2017
VFR through the period.
Another weak upper level impulse will skirt north of the area on
Tuesday, which may spark a few showers and perhaps a storm or two.
This is far too uncertain for inclusion at this point, and would
be more likely at LAF than the other sites.
Otherwise, some diurnal cloud cover will be possible mainly
tomorrow. Should see only partial cloud cover at any one time.
Winds will generally be west/northwesterly during the period.
Sustained winds will be as high as 8-12KT, and a few gusts to near
20KT cannot be ruled out tomorrow afternoon, but will only be
included at LAF for now.
No significant obstructions to visibility are expected during the
period.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM...JH
AVIATION...NIELD
Area Forecast Discussion
National Weather Service Elko NV
337 PM PDT Mon Jun 19 2017
.SYNOPSIS...High pressure will remain in control of the weather
across northern and central Nevada. Some high temperature records
are in trouble of being broken due to the heat. Look for the
continuation of isolated showers and thunderstorms developing in
the afternoons for Tuesday and Wednesday as mid-level moisture
seeps into the area. Temperatures will begin to cool by Thursday,
but still remain above normal levels with quieter and drier
weather returning.
&&
.SHORT TERM...Tonight through Wednesday. Afternoon thunderstorms
have begun firing across central Nevada as previously forecast.
HRRR runs have depicted activity spreading over Humboldt and Elko
counties in the early evening hours before slowly diminishing.
Current forecast tries to capture this trend. Precipitable water
from this morning`s sounding is showing about 135% of normal for
this time of year, and with surface dewpoints in the 40s and even
low 50s, some of the storms may be wet and could produce brief
rainfall. There was a cell that went near Eureka airport and
produced a wind gust of 45 knots, so gusty winds are definitely a
threat today, along with cloud to ground lightning strikes.
For tomorrow, afternoon highs should be slightly warmer with
readings in the mid to upper 90s. Numerical guidance is still
showing a few sites getting close to or breaking records as well.
Will have to contend with the afternoon development of showers and
thunderstorms once again. Biggest threats will be strong winds and
cloud to ground lightning.
By Wednesday, heights begin to recede slightly but should still
remain warm outside. Highs will remain well above normal for this
time of year with readings in the 90s to maybe 100 degrees in some
spots in northern Nye county.
.LONG TERM...Wednesday night through Monday. Models are showing a
drier flow trying to take shape on Thursday. The ridge is expected
to get depressed south, which will allow a weak northwest flow.
Overall, high temperatures will continue to remain above normal
through the period, but no records appear to be in jeopardy. The
weather is expected to be quiet, although by next week Monday,
some moisture tries to work its way north again, possibly bringing
some isolated showers and thunderstorms back to the area. Have not
put anything in the grids just yet, however.
&&
.AVIATION...Some thunderstorms are possible especially at the
northern TAF sites this evening, with the threat of strong winds
to 40 knots and MVFR cig/vsby. Otherwise, VFR conditions are
expected through the next 24 hours.
&&
.FIRE WEATHER...Near record high temperatures and low daytime
relative humidity are expected Monday and Tuesday. Mid-level
moisture will work its way northeastward into eastern and northern
NV tonight and Monday allowing for isolated dry thunderstorms
Monday and Tuesday. Winds will be relatively light through the
week staying below critical levels but relative humidity will be
at critical levels during the daytime.
&&
.HYDROLOGY...Warm temperatures will continue to promote snow melt
and elevated stream flows through the week.
Lamoille Creek is expected to remain in or fluctuate into minor
flood stage through the next several days.
The Humboldt River at Battle Mountain remains just below flood
stage and is expected to slowly fall this week.
The lower Humboldt River from Comus downstream through Winnemucca
to the Humboldt/Pershing County border continues to slowly fall
but will remain in minor flood stage for at least the next few
days.
Wildhorse Reservoir is still flowing over the spillway. There is
no threat for flooding at this time downstream along the Owyhee
River.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
86/86/86/86
Area Forecast Discussion
National Weather Service Louisville KY
940 PM EDT Mon Jun 19 2017
.Forecast Update...
Issued at 939 PM EDT Sun Jun 18 2017
Just a few clouds can be seen on satellite images remaining across
the region this evening. A very minor shower or two popped up across
the Bluegrass region earlier this evening, but since then we have
been dry. Have been watching the showers across IL this evening. The
latest trend in the HRRR has been for this rain to dissipate as it
moves into southern IN. This seems a reasonable solution given the
drier air in place. Therefore, have kept the forecast dry for
overnight and just adjusted pops up a bit into the 10% range.
Otherwise, no major changes were made to the forecast this evening.
&&
.Short Term...(This evening through Tuesday night)
Issued at 250 PM EDT Mon Jun 19 2017
A surface analysis this afternoon has the cold front now across
middle Tennessee and far eastern Kentucky. In its wake, westerly
winds have brought in drier air evident by recent RAP analysis
showing PWATs around 1 inch or less (compared to yesterday`s 2-2.2
inches) and dewpoints in the mid 50s to low 60s. Visible satellite
shows a scattered cumulus deck across much of the area, and
temperatures range from the upper 70s to low 80s.
A weak shortwave trough rotating through Indiana and Ohio has
sparked isolated to scattered showers/storms this afternoon. As this
activity pivots southeastward, a few may brush parts of southeast
Indiana and the far northern Bluegrass region. Have introduced just
a slight chance (10-15%) of a shower through about 6-8 pm.
Otherwise, the remainder of the area will see pleasant evening
temperatures and the cumulus field should dissipate toward sunset.
For tonight, the main concern is any fog potential. The combination
of light winds, clear skies, and wet ground may lead to patchy fog
in areas across south-central Kentucky and the Bluegrass. However,
sufficient mixing this afternoon may limit how much fog actually
forms, so have kept wording as patchy but there could be some
locally dense fog for Tuesday morning. Otherwise, plan on lows in
the low to mid 60s.
High pressure then builds into the region for Tuesday and Tuesday
night providing seasonable conditions and less humidity. Plan on
high temperatures in the low to mid 80s, and lows Tuesday night in
the 60s.
.Long Term...(Wednesday through Monday)
Issued at 255 PM EDT Mon Jun 19 2017
Upper pattern really de-amplifies on Wednesday, and afternoon temps
will recover above climo again after one more coolish morning.
Without much in the way of southerly flow, humidity will remain low
with dewpoints just around 60.
Low-level flow backs to southerly Wednesday night and Thursday,
allowing the dewpoint recovery to begin, and priming the atmosphere
for a potential remnant tropical plume late in the week. Could even
start to see precip into south-central Kentucky by late Thursday,
but this is not a high-confidence scenario.
POPs ramp up in earnest Thursday night as the remnant low lifts
through the Deep South, and will be maximized Friday into Fri night
as the wave opens up and gets picked up in the westerlies. Normally
would avoid likely POPs 4 days out, but even if the tropical plume
doesn`t pan out, there still remains the issue of a surface cold
front dropping in from the north. Will continue to roll with low-end
likely POP Fri and Fri night. Given this squeeze play, will need to
watch for a heavy rain threat in this time frame.
Temps Friday through the weekend will be modulated by clouds and
precip, so expect to be near or below climo by day and above by
night. Any tropical moisture should be sheared out on Saturday, but
a continued series of disturbances will support at least chance POPs
for most of the weekend, with cooler and drier air likely to follow
early next week.
&&
.Aviation...(00Z TAF Issuance)
Issued at 712 PM EDT Mon Jun 19 2017
Mainly VFR conditions are expected through this TAF forecast period.
The diurnal cu will continue to diminish this evening and winds will
become light and variable. Some light fog may be possible at BWG in
the morning. For the remainder of the day, winds will generally be
out of the west tomorrow with diurnal cumulus clouds developing
again in the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update...EER
Short Term...ZT
Long Term...RAS
Aviation...EER
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
951 PM EDT Mon Jun 19 2017
.SYNOPSIS...
A cold front will approach from the northwest tonight. It will
become stationary over the area Tuesday through Wednesday, then
dissipate. A trof of low pressure will develop over the middle
of the state Friday. A cold front will approach from the west
Monday.
&&
.NEAR TERM /TONIGHT/...
As of 950 pm Mon...No significant changes needed to previous
forecast for late evening update. Latest sfc analysis shows
998mb low pressure over Quebec with attendant cold front draped
through the NE/Mid-Atlantic regions and down into Western NC and
the deep south. Latest radar imagery shows large area of
showers and thunderstorms ahead of the front, extending from the
NE US coast down into the SE US. Convection continues across
central NC, with trends show weakening as it pushes E/NE. Light
showers could impact the coastal plain in the next hour or two.
Expect lull in precip across the area this evening, with better
chances late tonight and Tuesday morning, with models showing
area of convection pushing into the coastal plain late. Though
latest HRRR runs keep the precip moving more NE, impacting more
of the northern sections of the area. Adjusted previous pops
slightly based on trends and high res guidance, but will
continue likely pops inland and northern areas, with chance
elsewhere. Cannot rule out an isolated strong storm overnight,
but at this time threat appears low. Warm and humid overnight
with lows in the mid to upper 70s.
&&
.SHORT TERM /TUESDAY/...
As of 345 pm Mon...The front is forecast to become stationary
across the forecast area, providing a focus for showers and
thunderstorms. Time sections and forecast soundings show deep
layered moisture with precipitable water values around 2 inches.
Severe storms are not expected, but some could cause localized
flooding. Highs will be slightly cooler due to cloudy skies and
convection, in the lower 80s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 345 PM Monday...Typical summer pattern will continue this
period with Atlantic surface high pressure extending into NC
through the period. A couple of week cold fronts are forecast to
move into the area and dissipate, the initial front will be
over the area Tuesday night into Wednesday night, and the next
should occur over the weekend. While there are still differences
in guidance for a possible Tropical Cyclone over the Gulf of
Mexico this week, it appears that a feed of tropical moisture
from this system into our area will occur from mid week into the
weekend.
Tuesday night through Wednesday night...A broad upper trough digs
into the eastern CONUS this period while the attendant, slowly
dissipating, cold front advances into the region Tuesday and
Wednesday. Increasing S/SW flow will continue to bring abundant
moisture across region with forecast soundings indicating PWATs at
or above 2 inches while the region will be under favorable upper
level dynamics as the right entrance region of the upper jet
approaches. Scattered to numerous showers and thunderstorms are
expected through the period with best coverage likely Tuesday night
through midday Wednesday. Although SPC only has our area in the
"General" thunderstorm outlook both days, we still could see strong
convection especially Tuesday evening/night with favorable
instability and marginal shear of 25-35 kt present. Wednesday
continues to look less unstable but still expecting thunderstorms.
Any storms could also produce heavy rainfall with localized flooding
possible, especially if training storms develop. Cloudiness and
precip expected to keep highs in low-mid 80s Wednesday, despite low
level thicknesses 1400-1410 meters. Lows will range in the low to
mid 70s.
Thursday through Sunday...The upper trough lifts out late in
the week as upper ridging tries to build over the SE coast.
Complicating the forecast is the potential tropical moisture
feed from a Tropical system expected to form in the Gulf. This
would maintain the threat for a decent coverage of showers and
Thunderstorms late week which could be further enhanced if the next
weak cold front drifts south into the area. Very minor adjustments
to the previous forecast as guidance has changed little with
potential for high PoPs this weekend. Maintained PoPs from 20-30%
Thursday, highest for southwestern portions, to near climo (around
35-45%) Friday through the weekend. Seasonably warm temps are
expected with highs around 90 inland to mid 80s coast and lows in
the 70s.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term /through Tue/...
As of 650 pm Mon...VFR conditions this evening, though could see
sub-VFR conditions develop overnight and Tuesday morning with
cloud bases lowering as moisture increases from the west. Numerous
showers and scattered thunderstorms likely to impact the
terminals late tonight and into Tuesday, though tough to pin
down exactly with some models showing better precip chances in
the morning, while others develop more widespread precip in the
afternoon. Periods of sub-VFR likely Tue.
Long Term /Tuesday night through Saturday/...
As of 345 PM Monday...periods of sub-VFR conditions are likely
Tuesday night into Wednesday with scattered to numerous showers
and thunderstorms expected as a cold front approaches and
favorable upper level dynamics move into the region. Patchy late
night/early morning fog will also be possible, especially in
areas that receive rainfall. VFR conditions will return Thursday
though could still see isolated to scattered afternoon
showers/storms. Coverage of showers and storms, and thus
potential for periods of sub VFR conditions, could increase
Friday and Saturday if a feed of tropical moisture moves over
the area.
&&
.MARINE...
Short Term /through Tue/...
As of 950 pm Mon...Latest obs show breezy S/SW winds 15-25 kt
with gusts up to 30 kt and seas 4-6 ft. SCA continues for the
coastal waters, sounds and Alligator River. Used WaveWatch again
for the seas, as NWPS seas looked a bit too high. Gusty S/SW
winds will diminish a bit overnight, and then into Tuesday as
gradient relaxes.
Long Term /Tuesday night through Saturday/...
As of 345 PM Monday...Overall poor to fair boating conditions
expected through the long term. Guidance continues to indicate
generally southwest winds 10-20 kt to persist through period as
Atlantic high pressure prevails offshore with a weak trough
approaching from the northwest. Could see a weak wind shift
Wednesday night into Thursday morning as a weak front dissipates
over or near the waters. The southwesterly pressure gradient
between the offshore high and approaching front should remain
modest Thursday and Friday, but below Small Craft Advisory
levels. Wavewatch guidance for Friday and Saturday suggests 6-7
ft seas building into the outer fringes of the central and
southern coastal waters, but this is likely overdone as winds
will remain 10-20 kt, not a favorable regime for persistent seas
above 5 ft. NWPS and Wavewatch appear in good agreement during
the medium range, and capped seas at 5 ft for extended period.
&&
.TIDES/COASTAL FLOODING...
As of 345 pm Mon...Persistent long period SE swell will
continue to produce high threat of rip currents along all
beaches through Tuesday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement through Tuesday evening for NCZ095-098-
103-104.
MARINE...Small Craft Advisory until 4 AM EDT Tuesday for AMZ130-131-135.
Small Craft Advisory until noon EDT Tuesday for AMZ152-154.
Small Craft Advisory until 10 AM EDT Tuesday for AMZ156-158.
Small Craft Advisory until 6 AM EDT Tuesday for AMZ150.
&&
$$
SYNOPSIS...HSA
NEAR TERM...CQD/HSA
SHORT TERM...HSA
LONG TERM...DAG
AVIATION...DAG/CQD/HSA
MARINE...DAG/CQD/HSA
TIDES/COASTAL FLOODING...MHX
Area Forecast Discussion
National Weather Service Marquette MI
1158 PM EDT Mon Jun 19 2017
.SHORT TERM...(This evening through Tuesday)
Issued at 302 PM EDT MON JUN 19 2017
Water vapor imagery and RUC analysis reveals mid-upper level pattern
with a ridge over the western CONUS and broad trough into the
central CONUS including the Great Lakes region. Water vapor imagery
also revealed a series of shortwaves from MN and ND rotating through
the trough axis and into Upper Mi this afternoon. Weak daytime
heating under mostly cloudy skies has led to MLCAPE values of 200-
500 j/kg this afternoon enough to support scattered to numerous
showers mainly central and even some isolated t-storms along the WI
border. Given the fairly weak instability combined with minimal deep
layer shear expect only small hail with stronger storms into early
this evening despite lower freezing levels of 8-9 kft. Cool airmass
in place resulted in a cold air funnel sighting in Forsyth Township
in MQT county shortly after noon EDT so issued a SPS highlighting
potential of cold air funnels through the rest of the afternoon.
High temps have been mainly in the 60s with a few lower 70s readings
over southern MNM county. Look for scattered showers and isolated t-
storms to taper off late evening after sunset with the loss of
diurnal heating.
Tonight into Tuesday...Next best chance for showers and possible t-
storms will occur late tonight, after 09z Tue, as the stronger
shortwave trough over Saskatchewan and Manitoba dives se into the
Upper Great Lakes region. Scattered showers and isolated
thunderstorms (along WI border) will be possible into at least early
afternoon Tue as the shortwave works its way through the region and
MLCAPEs will be fm 100-250 j/kg, highest south central. Confluent
flow and mid-level subsidence/q-vector divergence in the wake of the
shortwave will provide for drying conditions west to east later Tue
afternoon. Despite breaks in the cloud cover Tue afternoon,
especially west half, high temps across area will be mostly in the
60s as models show h85 temps of 5-6c.
.LONG TERM...(Tuesday night through Monday)
Issued at 245 PM EDT MON JUN 19 2017
Overall, temperatures will warm back to near normal for this time of
year by the middle of the week, and then trend a bit cooler for this
weekend. The active weather is expected to continue with periodic
chances for showers and thunderstorms through the week and weekend.
Wednesday looks to stay mostly dry as weak ridging moves across the
Upper Great Lakes; however, as a strong shortwave digs south across
the area late Wednesday into Thursday, a cold front will push across
Upper Michigan bringing better chances for showers and
thunderstorms. The best chances look to be during the overnight
hours as a 40 knot low-level jet pushes northeast and ramps up the
900-700mb moisture transport across the area. The instability
doesn`t look terribly impressive, with MUCAPE values only showing
around 300-800 J/kg ahead of the surface trough as it traverses the
area, but with 40-50 knots of 1-7km bulk shear, a few strong storms
may try to pulse up occasionally. This cold front will push west to
east across Upper Michigan, and then exit the area by late Thursday
morning/early afternoon.
Friday another shortwave will push east across the area sending
another cold front into the area. With the better, deeper moisture
displaced well south of the area, do not think that we will see much
in the way of precipitation outside of perhaps some diurnal
sprinkles. With upper-level troughing lingering across the Upper
Great Lakes this weekend and a few shortwaves rotating about the
trough axis, temperatures should remain on the cooler side with
chances for showers.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 1157 PM EDT MON JUN 19 2017
Satellite imagery continues to show considerable mid-level clouds
over Lake Superior and moving southeast across the TAF sites this
evening. Expect this cloud cover to persist through the
overnight, but fortunately the bases appear to be at VFR conds or
4-5kft agl. Some guidance indicates CIGs will begin to fall just
prior to daybreak with another weak disturbance bringing a VCSH
possibly to TAF sites mid-morning Tue thru the aftn with CIGs
around 1500-2000ft agl. Confidence is not very high with CIGs aft
10z Tue.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 302 PM EDT MON JUN 19 2017
Winds should remain 20 kts or less into Wed, then may increase up to
25 kts Thu into Fri as a low pressure system and cold front cross
the Upper Great Lakes.
&&
.HYDROLOGY...
Issued at 302 PM EDT MON JUN 19 2017
Heavy rain of 1.25 to 1.75 inches that occurred over central Upper
Michigan on Sunday pushed the Sturgeon River near Nahma Junction in
Delta County to action/bankfull stage early this morning. Based
on current stage and rising trend along with additional rain from
showers this afternoon, will continue flood advisory through late
tonight.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...Ritzman
AVIATION...Beachler
MARINE...Voss
HYDROLOGY...Voss
Area Forecast Discussion
National Weather Service Reno NV
159 PM PDT Mon Jun 19 2017
.SYNOPSIS...
High pressure will bring much above average temperatures this week
with records possible through Wednesday. Isolated thunderstorms
will be possible Tuesday and Wednesday, mainly south of Highway
50. Snowmelt runoff will continue for the creeks and streams in
Mono County, with potentially more significant concerns for the
West Walker and mainstem Walker River.
&&
.SHORT TERM...
The upper wave that brought very isolated showers and thunderstorms
to the Sierra and western Nevada this morning has moved into
northeast California and Nevada, generally north of a Portola to
Lovelock line. Behind the wave, some minor subsidence has been
sufficient to delay/restrict the development of cumulus despite
strong daytime heating. As the afternoon wears on, a few higher-
based showers and thunderstorms cannot be ruled out in areas of
convergent lower level winds. The HRRR (short-term high resolution
model) continues to peg the best shot for deep convection east of
Highway 395 and near/north of Hawthorne, as well as north of
Eagle Lake, into the evening. With downdraft CAPE over 1500 J/KG
south of Interstate 80 per current SPC mesoanalysis, even weak
storms later this afternoon and into the evening could drop wind
gusts to 40-50 mph.
With no apparent upper waves tonight, any showers and/or thunderstorms
should die off by around sunset. Tuesday, flow aloft is simulated to
turn more southwesterly and increase slightly. Moisture never really
scours out Tuesday so isolated convective cells are expected again.
However, with the increasing southwest flow aloft the focus for
convection is expected to shift off the Sierra into the Basin and
Range, generally south of Highway 50. Low chances for storms were
left north of Susanville and Gerlach on Tuesday as well based on
12Z simulations showing a weak wave moving over that area along
with the typical surface convergence zone across northern Lassen
and Washoe Counties. However, the 18Z NAM is faster with the wave
so afternoon storms may be more favorable over Humboldt County with
just some cumulus over Lassen/northern Washoe Counties.
Wednesday, a disturbance moving by far to the north is progged to
induce northerly flow across western NV and far northeast CA as
surface high pressure builds into the Pacific NW. This is expected
to push the focus for afternoon convection to or slightly west of
the Sierra crest south of Tahoe. However, winds aloft will remain
light southwesterly so any convection that develops in the Sierra
could drift off into eastern Mono County so slight chances were
left there.
High temperatures remain well above average to near records through
Wednesday...so stay cool and hope for clouds. -Snyder
.LONG TERM...Thursday through Monday...
Ridge of high pressure gets flattened late in the week as low
pressure moves across the Pacific Northwest. This will help to lower
temperatures slightly with lower heights and cooler temperatures
aloft. High temperatures will still be very warm at 7 to 10 degrees
above average. Ridge axis shifts farther east over the Great
Basin by next weekend with warming temperatures and potentially
another round of thunderstorms Sunday-Monday of next week.
Snyder/Hoon
&&
.AVIATION...
The threat for thunderstorms at eastern Sierra and far western
Nevada terminals through this evening is much decreased compared
to the early morning thinking as the upper disturbance responsible
for this morning`s activity has moved north of KSVE and KLOL.
Still, areas in the Basin and Range east of Highway 395 (including
KNFL) and areas between KAAT and KSVE have a 10-20% chance for
thunderstorms through about sunset. Any storms will be capable of
dropping outflow winds to 35-45 kts.
Tuesday, isolated afternoon and evening thunderstorms are again
expected, generally south of Highway 50 and north of KSVE-Gerlach.
Similar outflow winds as today could accompany any storms on
Tuesday. Snyder
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno