Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/10/17
Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Fri Jun 9 2017
.UPDATE...
Issued at 1011 PM EDT Fri Jun 9 2017
All diurnally-driven shower activity has died with sunset as
expected late this evening....leaving partly to mostly clear skies
across our entire CWA. Winds have become light/calm...allowing
temps to quickly fall thru the 60s...on their way to overnight
lows in the upper 40s and lower 50s. Going forecast is on
target...no changes needed at this time.
&&
.NEAR TERM...(Tonight through Saturday)
Issued at 407 PM EDT Fri Jun 9 2017
...Showers and Thunderstorms Ending by the evening. ...
High Impact Weather Potential...None
Pattern Synopsis/Forecast...Small 500 mb shortwave trough is pushing
through the flow into N Lower and E Upper this afternoon and will
continue into Lake Huron by 03z. Latest HRRR is handling this pretty
well, maybe a little overdone, on qpf, but the general areas where
the convection is breaking out pretty good. As the shortwave moves
through, the drier air in the 700-500 mb layer (RH<20%) and around
850 mb (rh< 20% as well) clears things out. Saturday will remain dry
as the 500 mb ridge builds into the region and pushes the main
thunderstorm threats to the north of Lake Superior. This will allow
our temperatures to warm to the lower to mid 80s.
Primary Forecast Concerns...As this area of showers and
thunderstorms moves through the region, they could linger a little
longer than 00z, but the main idea is that they will die out as they
lose heating.
Temperatures Saturday could climb a little higher as the
temperatures mix to about the mid to upper 80s, but cloud cover from
convective debris across the lake, could affect the region so have
gone with the middle ground.
&&
.SHORT TERM...(Saturday night through Monday)
Issued at 407 PM EDT Fri Jun 9 2017
...Warmer, but periodic showers and thunderstorms...
High Impact Weather Potential...periodic thunderstorm chances...
marginal risk for severe storms.
Primary Forecast Concerns...Thunderstorm/severe weather potential
and temperatures through the weekend.
Pattern Synopsis/Forecast...Trough/Ridge/Trough pattern across the
CONUS this morning with a closed low off the PAC NW coast...ridging
and warm air through the plains into the Midwest and a departing
trough in New England. Upper level ridging/warm air will shift into
the Great Lakes region this weekend...although flatten a bit as PAC
NW trough migrates inland and short wave energy/surface low pressure
eject through the northern plains and far northern Great Lakes
region...along with a cold front that may settle into the northern
lakes region by Sunday. This has big implications for
temperatures...and our warming trend for northern Michigan may not
end up as robust as earlier advertised as temperatures may be
tempered by one or more convective systems/cloud cover/debris that
will develop along the periphery of the ridge and along the
front...not to mention the ultimate location of the front itself.
Saturday night into Sunday...Aforementioned short wave energy and
attending surface low will be sliding quickly through Ontario and
Quebec with a trailing cold front folding into northern Michigan
heading into Sunday. Convective development remains a possibility
in the upper Midwest Saturday night...and sliding through the
northern lakes into Sunday morning...with lingering cloud cover
draping across northern Michigan a possibility for Sunday. Of course
If that occurs...high temperatures for Sunday will be cooler than
previously advertised...perhaps much cooler. A lot of uncertainty
here, but plan is to beef up cloud cover and lower high temps for
Sunday. But again, much will depend on convective evolution and
where the boundary ends up.
Front remains draped across the northern lakes region...back to
another area of low pressure in the front range of the Rockies.
Another round of showers/storms may develop again in the upper
midwest late Sunday with pooling moisture/instability along the
boundary and where stronger low level flow will be focused...and
potentially sliding through the northern lakes region heading into
Monday. Again, much uncertainty surrounds this pattern (where stuff
will develop, where it goes)...like my inherited forecast with
showers/storms Sunday night into Monday and a slightly cooler/
cloudier forecast for Monday.
Severe weather possibilities...any convection that develops and
moves through the region through the weekend will have a fair amount
of instability and stronger mid level flow to work with and could
produce some strong-severe storms...as outlooked with the SPC Day 2
and Day 3 products.
.LONG TERM...(Monday night through Friday)
Issued at 407 PM EDT Fri Jun 9 2017
The weather in the extended looks unsettled, to say the least.
Models show waves passing over the great lakes ahead of a more
robust low pressure system that will move through around Thursday.
Timing of this activity will be the forecast challenge ahead...as
guidance indicates at least chance pops in each period through
the extended. That said, I suspect we will lack the moisture for
such continuous activity and instead will see shots of showers and
even a few thunderstorms...with longer periods of rain free
conditions. Thursday looks like the best day for the most
widespread appreciable rainfall. Temperatures will run seasonal to
a touch above...with daytime highs generally in the 70s, to lower
80s.
Berger
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 1145 PM EDT Fri Jun 9 2017
Dry wx and mainly VFR conditions are expected at all TAF sites
tonight thru Saturday evening. A warm front will lift thru the
region on Saturday. No precip is expected across Northern Lower
Michigan with the passage of this front. However...southerly winds
will greatly increase once the front lifts thru the area. Surface
winds will strengthen to 15 to 25 kts by Saturday afternoon with
higher gusts expected. LLWS will develop by early evening in
response to some low level decoupling and further strengthening of
wind speeds just off the deck.
&&
.MARINE...
Issued at 407 PM EDT Fri Jun 9 2017
Tonight through Sunday...Winds will gradually increase tonight and
into Saturday as the gradient tightens up winds look to ramp up to
small craft sustained winds, in all of the nearshore waters.
However, from Manistee to Grand Traverse Light am expecting the
gusts to be over Gale force as the coastal convergence and the
funneling of the Manitou Passage helps to accelerate wind speeds.
Saturday night, as the low to the north, that tightened the gradient
passes to the east, the gradient slackens winds will diminish.
Sunday, winds and waves will be light and under 2 feet as high
pressure passes through the region.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY from 10 AM Saturday to 6 AM EDT Sunday for
LHZ345>349.
LM...SMALL CRAFT ADVISORY from 10 AM Saturday to 6 AM EDT Sunday for
LMZ323-341-342.
GALE WARNING from 10 AM Saturday to 6 AM EDT Sunday for
LMZ344>346.
LS...SMALL CRAFT ADVISORY from 10 AM Saturday to 6 AM EDT Sunday for
LSZ321-322.
&&
$$
UPDATE...MLR
NEAR TERM...JSL
SHORT TERM...TBA
LONG TERM...KAB
AVIATION...MLR
MARINE...JSL
Area Forecast Discussion
National Weather Service Bismarck ND
846 PM CDT Fri Jun 9 2017
.UPDATE...
Issued at 829 PM CDT Fri Jun 9 2017
Quick update for observed trends through 01 UTC and CAM trends
through the 00 UTC HRRR iteration. Severe convection will
continue across the James River Valley for the next one to two
hours. At the same time, covection continues to increase across
southeast Montana. The 00 UTC HRRR, 21 UTC ESRL HRRR and 18 UTC
NAM NEST continue to support intensitifaction of this convection
into southwest and south central North Dakota late tonight in a
highly sheared, strongly forced environment on the nose of a
strong (75-80kt) 500 mb jet. Damaging wind gusts from high based
and rapidly propagating storms is the primary threat, with large
hail a secondary concern.
UPDATE Issued at 519 PM CDT Fri Jun 9 2017
Quick update to issue severe thunderstorm watch #309 through
midnight CDT. See SPC watch discussion for details. The 21 UTC
HRRR, 18 UTC ESRL HRRR and the 18 UTC NAM NEST all support the
continued threat for a second round of severe convection in a
high shear/low CAPE environment entering from Montana between
04-06 UTC tonight and rapidly propagating east into central North
Dakota.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 302 PM CDT Fri Jun 9 2017
Potential for significant severe weather exists this afternoon all
the way through the overnight, with two separate regimes yielding
potential hazards.
...Severe-Risk Number One...
* Location/Timing...Along and east of Highway 83 from about 21 to 03
UTC.
* Scenario/Technical Discussion...Strong surface pressure falls of
3 mb/3 hours are driving gusty south winds and moisture return
this afternoon as a lee-side pressure trough moves eastward. The
nose of low-level warm air advection is focused near Minot as of
19 UTC, where the trough intersects a warm front producing a
triple point of air masses. Surface dewpoints are running a bit
lower than expected based on earlier model guidance, and they
have dropped from 59 to 54 F at Bismarck between 1830 and 1930
UTC, suggesting the richer moisture is relatively shallow and is
susceptible to reduction via mix-out. An early look at our 19
UTC special sounding verifies earlier model expectations for a
strongly veering wind profile with its associated deep-layer
shear vectors oriented normal to the surface trough in favor of
discrete supercells where convective initiation occurs. The main
uncertainty is how many updrafts will be able to survive their
trip to the LFC given lingering capping (also shown on our 19
UTC sounding). CAM guidance has been exceptionally consistent in
advertising a high probability of supercell development on the
nose of the greater warm air advection, near the triple point,
in the Bottineau/Rolette/Pierce County area by late afternoon.
In that area, large low-level hodographs with 0-1-km SRH of 150
m2/s2 support a tornado risk, tempered by MLLCL heights near
1500 m AGL (though lingering cloud cover could keep surface
moisture content relatively more protected from mixing in those
areas in support of lower LCL heights). Further south, guidance
is widely dispersive in whether isolated supercells will form in
south central ND, so confidence is lower, but if any storms do
become established the environment will be characterized by
MLCAPE of 2000 J/kg and 40 kt of 0-6-km bulk wind shear. There`s
long been a signal in sounding analog retrieval system output
for very large hail in this setting. Again, though, only a few
storms may develop, especially south of Highway 200, with this
first severe risk.
We greatly appreciate the research and academic groups, including
NSSL and the College of DuPage, who are providing very useful
sounding data across the area this afternoon as we determine when
and where convective initiation will take place.
...Severe-Risk Number Two...
* Location/Timing...Southwest and central North Dakota from about
03 to 12 UTC. The threat may be highest between Interstate 94
and Highway 2, but that area may be refined with later updates,
with the most recent guidance suggesting the Interstate 94
corridor may be favored.
* Scenario/Technical Discussion...Height falls aloft and an
eastward-advancing cold frontal zone will likely generate deep,
moist convection in southeast MT this evening with upscale
growth and forward propagation downstream into ND overnight. It
appears that late afternoon and early evening convection forced
on the pre-frontal trough will not be widespread enough to
overturn the instability axis over ND, and in fact the 12 UTC
global suite and more recent RAP/HRRR iterations all suggest an
enhanced elevated mixed layer pulse will surge into central ND
in advance of the cold front, yielding very steep lapse rates of
8.5 C/km in support of MUCAPE from 1000-2000 J/kg despite low-
level moisture that will not be particularly rich. Strengthening
flow aloft will yield intense vertical wind shear with effective
bulk wind differences of 60 to 70 kt. This scenario supports an
outcome in line with today`s CAM simulations with a mix of both
supercells and small bowing complexes racing northeast across
the area overnight. Even if the updrafts are elevated, the very
strong environmental flow and downshear MCS propagation vectors
of 70+ kt support potentially destructive winds. CAM solutions
including the large majority of the 12-17 UTC HRRR cycles have
shown updraft helicity values of 100-150 m2/s2 with these storms
in support of significant-severe potential. Even the 12 UTC NSSL
WRF-ARW depicts a similar signal, and its HAILCAST output shows
potential for golfball or larger size hail suggesting that wind-
driven hail damage is possible. Experimental time-lagged HRRR
convective guidance also strongly supports overnight wind and
hail risks. The main uncertainty is coverage of this round of
severe storms and how far south they form, but both the 12 UTC
NSSL WRF-ARW and 17 UTC deterministic HRRR suggest that the
Interstate 94 corridor, including Bismarck/Mandan, could be in
the risk area. Note that this synoptic and mesoscale scenario
does resemble the June 16-17, 2016, event enough for it to be
considered a viable analog, but that of course does not imply
the outcome will be identical, particularly with regard to which
areas are impacted.
A cooler, but still warm, and breezy Saturday will follow in the
wake of tonight`s cold frontal passage. Steep mid-level lapse
rates from cold advection aloft could yield a few showers north.
Low-level drying will push afternoon humidities to 20 percent in
parts of western and north central ND, but the spatio-temporal
overlap of dry air, humidities, and dry fuels does not appear
significant enough to warrant a red flag warning.
.LONG TERM...(Saturday night through Friday)
Issued at 302 PM CDT Fri Jun 9 2017
The main focus in the long term is on the dynamic and very strong
upper-level low expected to lift from the Great Basin northward to
Montana by Tuesday. The 12 UTC GFS and ECMWF both continue showing
the greatest wrap-around moisture accompanying this wave remaining
west of the local area in Montana. However, diffluent flow ahead
of the wave Monday and early Tuesday will favor a wave of showers
and storms lifting northward, with locally-heavy rain possible. A
risk of severe weather will exist given strong wind fields and at
least elevated instability north of a surface low that lifts
northeast across the region. Depending on how far north the warm
sector moves, surface-based storms are not out of the question.
Finally, the close proximity of the cold-core low could favor a
localized severe storm risk on Tuesday, as well.
Thereafter, cooler and mainly dry cyclonic flow is likely during
the latter parts of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 829 PM CDT Fri Jun 9 2017
Severe thunderstorms will continue across the James River Valley
through 03 UTC. Thunderstorms developing across southeast Montana
as of 0145 UTC will continue to intensify and move into western
and central North Dakota late tonight. Some storms may be severe
with damaging winds and large hail. Thunderstorms are expected to
cross the North Dakota and Montana border between 06-07 UTC and
spread east rapidly.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...AYD
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1153 PM EDT Fri Jun 9 2017
.AVIATION...
Weak low pressure has moved east and remaining sct-bkn lower vfr
deck will be east of KMBS by 06z (already clear elsewhere). VFR
conditions are then expected the entire forecast period. Southwest
winds will become gusty by midday Saturday with advent of warmer
airmass. Gusts could approach 30 knots KMBS, but generally range in
the 22-26 knot area during best afternoon mixing.
//DTW THRESHOLD PROBABILITIES...
* None.
&&
.PREV DISCUSSION...
Issued at 354 PM EDT Fri Jun 9 2017
DISCUSSION...
Storm chances this evening will likely be followed by a lengthy
period of hot and dry weather persisting from Saturday through next
Tuesday. Temperatures will likely reach into the low 90s for several
of those days.
First off we`ll address thunderstorm chances for this afternoon and
evening. Not too much has changed in the though process since the
morning update. The morning shortwave continues to hang over a
portion of the Detroit Metro with scattered showers ongoing.
Satellite images now show the next wave and jet max surging through
WI over Lake MI. A weak surface low drifting along a weakening
trough laid out across far southern MI will be aided by an upper
level shortwave and jet max to spark the next round of showers and
thunderstorms. The shadow of Lake MI is producing a differential
heating boundary which has started CUing up already. Surface
temperatures have overachieved by a couple degrees adding a bit more
surface based instability over the west side of the state, but both
the HRRR and RUC SCAPE have decreased in recent model runs to below
500 J/kg. They`ve consistently been advertising a warm layer around
850mb to have to overcome to be sfc based so it`s not surprising
with clouds hanging around keeping temps near 70, and the warm
bubble around 850mb that SCAPE would be low. In the end, we still
expect scattered thunderstorms to develop this evening across the
area, with the best chance between I69 and I94 and mainly between 21-
01Z. A weak wind profile resulting in a lack of shear will keep a
pulse type mode to the storms and should limit any severe potential.
Big pattern changes coming this weekend. The persistent trough that
has been plaguing the region for quite some time now will push off
to the east while a deep upper low drops south over the West Coast.
This will in turn bring about strong ridging across the Plains and
into the Great Lakes. Both the GFS and EURO bring 850mb temps in the
upper teens into the region, with decently dry air folding in from
the Northern Plains. This should promote strong warming trend with
temps around 90 Sunday through Tuesday. The baroclinic zone will be
laid out to our north which may bring some nocturnal MCS activity
through Mid/Northern MI at times, but will say mainly warm and dry
for now and deal with short MCS`s on more of a short term basis.
Looks like the upper low will drift eastward through mid week
possibly sending a cold front through the region Tuesday night or
Wednesday. A later passage may allow temps to again climb into the
90s on Wednesday.
MARINE...
A weak area of low pressure will slowly drift across Lower Michigan
this afternoon and evening. Given the weak pressure gradient
associated with this feature, surface winds will remain light an
variable on Lake Huron. Developing southwest winds will increase on
Saturday as a sprawling surface high remains parked over the
southeastern United States. Warm temperatures advecting with these
winds will greatly limit mixing depths over the lakes. The gradient
along may however support gusts over 20 knots at times, particularly
during the latter half of the weekend. The exception will be over
the Saginaw Bay region Saturday evening and night, when a small
craft advisory will likely be needed.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....DG
DISCUSSION...DRK
MARINE.......CB
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
908 PM CDT Fri Jun 9 2017
.UPDATE...
Mesoanalysis reveals CIN quickly developing over the CWA with loss
of daytime heating. As a result storms continue to diminish over the
area, with just two lone cells remaining across southern Blanco and
southwest Hays counties. These may impact portions of Comal county
before dissipating over the next hour or two. Re-adjusted POPs and
hourly T/Td trends for remainder of evening.
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT Fri Jun 9 2017/
AVIATION... /00Z TAFs/
There is an isolated severe threat mainly west of AUS, and a few
showers and thunderstorms have a chance to produce lightning and
gusty winds in the AUS vcnty through around 03Z. Afterwards, a
benign forecast is expected with most of the rapid refresh models
keeping the convection just outside the San Antonio metro area.
Overnight skies should be partly cloudy for the most part but pockets
of mvfr cigs are expected to form over the I-35 terminals toward
daybreak. CIRA SIMWRF fog product has the clouds forming first at
SAT/SSF, so the forecast will continue to show a slight delay before
cigs form over AUS.
PREV DISCUSSION... /ISSUED 305 PM CDT Fri Jun 9 2017/
SHORT TERM (Tonight through Saturday)...
Main forecast concern through the next 6-12 hours will center around
scattered storm chances for portions of the Hill Country and I-35
corridor. Rain chances have been increased during the 5pm to 11pm
time-frame to 40% these areas. A storm or two may become strong with
very localized wind gusts of 30-40 mph and small hail. This risk is
low and coverage is not expected to be large across the region.
Please see below for more details.
Water vapor and RAP analysis depict a positively tilted trough
shifting across NE Texas. The base of the trough will brush across
south-central Texas through the afternoon and early evening and
coincide with maximum instability near 2500 J/Kg. A weak capping
inversion remains in place per aircraft soundings out of KAUS and
KSAT but it should weaken just enough to allow for some isolated to
scattered showers and thunderstorms to develop. Such convective
development has already shown some signals of occurring north of the
region near a small MCV apparent on visible satellite. Hi-res model
trends continue to point towards the development of these showers and
storms across the east Hill Country and northern I-35 corridor. With
DCAPE near 800 J/Kg and weak upper level divergence, a storm may
become strong with small hail and gusty winds. These storms should
not have great overall coverage and remained confined to the I-35
corridor region through the late afternoon and evening. Expect what
storms do develop to weaken by midnight.
Saturday will be a quieter day as the trough actually closes off over
the Texas coast but the region will be on the drier northern flow,
negative vorticity advection area, with slightly lower PWATs. There
could be some limited sea-breeze activity along the Texas coast but
it unlikely to make into the coastal plains and have gone with a dry
forecast with near normal temperatures.
LONG TERM (Sunday through Friday)...
Seasonal pattern of sea-breeze activity will be the main set-up
through late weekend and through much of next week. Coastal plains
will have a 20-30% chance of rain and general thunderstorms each
afternoon with some of this making into the I-35 corridor late into
the afternoons each day. Areas west of I-35 will remain hot and dry
with heat indices reaching into the low 100s.
A weak sub-tropical atlantic H5 ridge and weak H85-H7 inverted
trough along the south Texas coast will aid in moist SE flow through
the week. Daily sea-breeze activity is expected with little to no
expected activity west of I-35. This pattern will persist through
much of next week. Areas will warm into the low to mid 90s each day
with some pockets of upper 90s along the Rio Grande. Heat index
values will increase to 100-105F and precautions should be used
during this heat.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 70 91 72 92 73 / 20 - - 10 -
Austin Bergstrom Intl Airport 68 90 71 91 72 / 20 - - 10 -
New Braunfels Muni Airport 69 90 70 92 72 / 10 - - 10 -
Burnet Muni Airport 68 89 69 89 70 / 20 - - 10 0
Del Rio Intl Airport 73 96 73 96 73 / - - - 0 0
Georgetown Muni Airport 69 90 71 90 72 / 20 - - 10 -
Hondo Muni Airport 71 93 71 93 72 / 10 - - - 0
San Marcos Muni Airport 69 91 71 91 72 / 20 - - 10 -
La Grange - Fayette Regional 69 90 72 91 73 / 10 - - 20 10
San Antonio Intl Airport 71 91 72 93 73 / 10 - - 10 0
Stinson Muni Airport 71 92 73 93 73 / 10 - - 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...Oaks
Synoptic/Grids...Runyen
Public Service/Data Collection...YB
Area Forecast Discussion
National Weather Service Grand Rapids MI
1147 PM EDT Fri Jun 9 2017
LATEST UPDATE...
Aviation
.SYNOPSIS...
Issued at 314 PM EDT Fri Jun 9 2017
A dry and breezy day is expected Saturday as temperatures climb
well into the 80s. Upper 80s to low 90s are forecast into the
first half of next week before some cooler temperatures and a risk
for rain returns.
&&
.UPDATE...
Issued at 943 PM EDT Fri Jun 9 2017
A few isolated showers remain over Gratiot and Isabella Counties
but those will be gone soon. Otherwise a dry/pleasant night is in
store with comfortable overnight lows around 60.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 314 PM EDT Fri Jun 9 2017
Scattered evening showers and thunderstorms, mainly east of US 131
and especially toward US 127, will give way to a dry overnight
period and a dry (but breezy) Saturday. A few showers or
thunderstorms may reach far west central Lower MI both Sunday
morning and then again late Sunday. Severe weather looks unlikely
for this region on Sunday but the threat is not zero.
Still expecting some showers and perhaps a few thunderstorms to
develop through the evening as the lake shadow presses inland and a
surface low moves overhead. SBCAPE readings of 1000 J/kg or more are
shown by the RAP and GEM which is sufficient for thunderstorm
activity. With weak wind fields at the surface and aloft, deep layer
shear is low, and organization will be loose. No strong storms are
anticipated. Any convective activity will be rapidly moving out and
winding down as we approach 00z.
Saturday is looking dry and warm, but breezy. Model guidance is
consistent in showing 25-35 mph wind gusts during the afternoon and
evening hours. We can`t rule out wind gusts approaching 40 mph
especially across west central Lower MI, particularly near Lake MI.
This is supported by Bufkit cross sections using the NAM and GFS. We
don`t have to mix very high to obtain the 30-35 kt winds...only 1000
ft or so.
Finally, there is a low probability of remnant MCS activity to
impact areas near and north of US 10 early Sunday morning. Most
likely any storms that develop across northern Wisconsin into the
U.P. will be fading as we approach 12z Sunday, in spite of the
MUCAPE axis shifting into central Lower MI by that time. Still a
low chance that this region may get clipped by a few showers and
storms. Sunday afternoon, a 25-30 kt LLJ core will be oriented
across central Wisconsin stretching into central and northern
Lower MI. SBCAPE of 1000 J/kg or more will develop especially
across central Lower MI Sunday afternoon and evening. This area is
also closer to a weak H500 shortwave impulse moving over the cusp
of the ridge that will be establishing itself. Low POPs are
warranted for this area, though it seems like the bulk of the
thunderstorms will be further north.
.LONG TERM...(Monday through Friday)
Issued at 314 PM EDT Fri Jun 9 2017
The last prolonged heat wave of note in GRR/LAN area was from July
15 through the 19th 2013, when Grand Rapids highs were at or
above 90 degrees for 6 days from the 14th through the 19th. It was
at or above 95 degree on 4 of those 6 day. In Lansing it was
similar 5 days at or above 90 and 3 days with highs of 94. Battle
Creek, Kalamazoo, and Jackson`s numbers were very much like
Lansing during the July 2013 heat wave. All had 5 days with highs
of 90 or higher from the 15th through the 19th. My point is I can
seriously see most of the area near and south of I-96 and inland
of US-31 having highs in the lower to mid 90s from Sunday through
Wednesday. If this happens it will not exceed the last heat wave
in July 2013 (June and July of 2012 had more extreme heat waves in
this area) but it will be our longest and hottest since 2013.
The models continue to show the lead Pacific storm (one of 3) coming
on shore on Saturday. That results in an omega block from the
dateline to western United States. With that upper low over the
western CONUS, a large upstream ridge builds over the eastern CONUS.
Meanwhile a polar vortex looking feature develops over Hudson Bay.
This will create quiet the baroclinic zone along the Canadian Board
where the Canadian Polar Air air meets the subtropical air. It is there
where all the convection should be from Sun through Tuesday, or
really Wednesday afternoon. Finally the next of the large Pacific
storms (storm 2) boots the first system east and shears it out
over the eastern upper ridge. Typically the models do this too
fast and weaken the system too quickly. I am thinking the
associated cold front will be slower and stronger. That means we
would still be in the heat Wednesday and would not get the
convection with the cold front till Wednesday night or Thursday.
One of the aspects of why I think it will be so hot is it has been
rather dry over a large part of our area since early May. With the
high solar angle, there is little in the way of water to evaporate
from the soil to heat it. I believe this is part of the reason our
forecast highs have been running 4 to 8 degrees to cold day after
day for nearly 2 week now. Also I believe the convection with the
front will be near and north of route 10 and with a largely westerly
wind at mid to upper levels we will not be seeing a lot of MCS cloud
debris most of this time either.
Finally in the Thursday time frame that closed upper low shears out
enough to bring cooler Pacific air into Michigan. Since we could be
seeing a stretched, slow moving front we could be looking at several
days of thunderstorms Thu into Fri or even Saturday. We will likely
any cool below normal till at least early in the following week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1130 PM EDT Fri Jun 9 2017
VFR conditions will continue at all the terminals through Saturday
evening. South to southwest winds will increase significantly from
mid to late Saturday morning through the afternoon and early
evening gusting and gust to near 30 kts at times Saturday
afternoon. Wind speeds will diminish to around 10-15 kts by mid
evening Saturday and remain out of the south to southwest.
&&
.MARINE...
Issued at 943 PM EDT Fri Jun 9 2017
Issued a Beach Hazard Advisory earlier for Saturday, for the
coastal counties bordering the Gale Warning. Earlier discussion
below.
Upgraded the SCA from Holland to Manistee to a Gale Warning.
Bufkit soundings support 35 kts or greater especially across the
northern half of this region, but gales are certainly possible as
far south as Holland given the southerly flow rapidly
strengthening over the lake. Saturday afternoon looks rough with
large waves building into the 4 to 7 foot range or greater,
especially near and north of Holland. These rough waters will
persist into Sunday morning.
&&
.HYDROLOGY...
Issued at 1249 PM EDT Fri Jun 9 2017
Scattered showers resulted in very little measurable rainfall last
night. Most reports came in under five-hundredths of an inch.
Additional showers and thunderstorms could develop today, mainly
east of Grand Rapids. Localized, brief periods of heavy rain
could develop, but should not have much of an impact on rivers.
Given recent dry weather and near normal stream flows, flooding
concerns are nil at this point. The weekend continues to look
mainly dry with a storm track focused north of Grand Rapids.
Portions of central Lower Michigan could see rain chances increase
Sunday night. However, the nighttime mode of convection is
relatively hard to capture with exact timing/placement. Any
variability could make a notable difference in resulting
precipitation amounts.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from Saturday afternoon through late
Saturday night for MIZ037-043-050-056.
LM...Gale Warning from noon Saturday to 5 AM EDT Sunday for
LMZ846>849.
Small Craft Advisory from noon Saturday to 5 AM EDT Sunday for
LMZ844-845.
&&
$$
UPDATE...Meade
SYNOPSIS...Hoving
SHORT TERM...Hoving
LONG TERM...WDM
AVIATION...Laurens
HYDROLOGY...JAM
MARINE...Meade
Area Forecast Discussion
National Weather Service Mount Holly NJ
935 PM EDT Fri Jun 9 2017
.SYNOPSIS...
High pressure located over the western North Atlantic is
forecast to influence our weather into Tuesday. A cold front
from the north is expected to pass through our region on Tuesday
night. High pressure is anticipated to build from eastern
Canada to the waters off New England on Wednesday and Thursday.
A warm front approaching from the southwest is expected to
arrive on Thursday night or Friday.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Weak trough at both the surface and aloft lies along the East
Coast and is moving offshore.
Low pressure currently over the Great Lakes continues to track
east and will move into western NY/PA. Clouds associated with
this low will increase and thicken tonight. That low moves into
central NY by daybreak Saturday, and isolated to scattered
showers and thunderstorms are then possible in the pre-dawn
hours on Saturday for far northern and western zones, generally
along and north of I-78. Several hours ago the HRRR was rather
bullish on shower coverage and intensity. However, over the
last few runs it has fallen in line with the other mesoscale
models. A lower coverage of any showers/ thunder associated with
the system makes sense given the dry airmass currently. The
timeframe for any precipitation will likely be just after
sunrise.
Lows tonight will be considerably warmer tonight in the 50`s
outside of the Philly region.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
Low pressure over central NY continues to track to the east
during the day Saturday and departs by early evening. A frontal
boundary will trail behind the low and will pass through the
region as a warm front in the afternoon. Isolated to scattered
showers and thunderstorms possible across areas mainly to the
north of I-95 through the day.
Downsloping westerly flow will help turn temperatures much
warmer on Saturday. Highs will be in the upper 70s across the
Poconos, otherwise in the low to mid 80s across NW NJ and into
the Lehigh Valley. For the rest of southern NJ, SE PA, and the
Delmarva, highs will be in the mid to upper 80s, possibly
touching 90 in some spots. Areas right along the shore will be
much cooler.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Ridging at the surface and aloft will likely result in an
increase in heat and humidity during the period from Sunday
through Tuesday. A developing Bermuda high will cause a very
warm and humid southwest flow to develop. We will not issue any
Heat Advisories or Excessive Heat Warnings at this time since
our region should remain mostly below the criteria. However, we
are keeping an eye to Tuesday and our highly urbanized areas for
a potential excessive heat/humidity event.
A mid level trough is forecast to pass across New York State
and New England on Tuesday night and it should push a back door
cold front through our region at that time. We will mention
either a low or slight chance of showers and thunderstorms.
High pressure to our northeast is expected to influence our
weather for Wednesday and Thursday with a decrease in both heat
and humidity levels.
A warm front is anticipated to lift through our region on
Thursday night or Friday bringing another chance of showers and
thunderstorms.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Overall, VFR conditions tonight and Saturday.A scattered to
broken mid-deck is expected around 7,000 feet through the TAF
period. The broken conditions are expected to be more
prevailing just after sunrise from Philadelphia and points
north. A tempo group has been added for VFR showers for RDG and
ABE given the possibility of brief precipitation. Any thunder
coverage looks far too low for inclusion in the TAFS attm.
W to SW winds increase to 5-10 KT late Saturday morning. By
afternoon, winds become 10-15 KT with occasional gusts up to 20
KT.
OUTLOOK...
Saturday night through Monday...Mainly VFR.
Monday night and Tuesday...Mainly VFR. There is the possibility
of low clouds and reduced visibility during the late night and
early morning hours.
Tuesday night and Wednesday...Mainly VFR with the possibility
of MVFR ceilings on Tuesday night and Wednesday morning along
with a low or slight chance of showers and thunderstorms.
&&
.MARINE...
Sub-Small Craft Advisory conditions on tap as SW winds will be
10-15 KT tonight through Saturday. Gusts to 20 KT Saturday
afternoon. Ocean seas will range from 3-4 feet and seas on DE
Bay will be 1-2 feet.
OUTLOOK...
Saturday night through Wednesday...No marine headlines are
anticipated.
RIP CURRENTS...
A moderate risk for the formation of dangerous rip currents
remains in place through Saturday for the New Jersey coastline.
This is mainly due to the proximity to the full moon and gusty
winds in the afternoon. The risk is lower for Delaware.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
Synopsis...Iovino
Near Term...Gaines/MPS
Short Term...MPS
Long Term...Iovino
Aviation...Gaines/Iovino/MPS
Marine...Iovino/MPS
Area Forecast Discussion
National Weather Service San Diego CA
151 PM PDT Fri Jun 9 2017
.SYNOPSIS...
A trough of low pressure will bring cooler weather along with
extensive clouds west of the mountains this weekend. Strong winds
are expected each afternoon and evening in parts of the mountains
and deserts. High pressure will bring fair weather, less coastal
cloudiness and a gradual warming trend next week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
This afternoon, skies are mostly clear except for a few marine
layer clouds at the immediate coast of south San Diego County. A
few cumulus have also developed over the mtn peaks courtesy of
daytime heating mixing out the boundary layer. Chances are good
that the low clouds spread inland again tonight, although they may
be less well organized.
A low pressure trough over the West will increase the onshore
flow and strengthen winds through mountain passes and into parts
of the deserts each afternoon and evening through Sunday. Sunday
afternoon/evening is likely to be the windiest period, with Isolated
gusts exceeding 45 mph in wind-prone areas like the San Gorgonio
Pass, however most gusts will remain below that over most of the
deserts. The marine layer will deepen, but the cold air associated
with the trough will serve to weaken the marine inversion and
produce better mixing of the boundary layer. That will mean
extensive low clouds filling the coastal basin and moving up the
mountain slopes, but probably not full or uniform cloud coverage.
The clouds don`t appear thick enough for any precip until Saturday
night when just enough energy could produce drizzle or even light
rain. The influx of cooler air associated with the trough will
make it unseasonably cool this weekend. Sunday`s high temps will
be from 5 to 20 degrees below average. On Monday, the trough moves
to the northeast and the marine layer will become shallower.
Slowly building high pressure next week will bring a gradual
warming trend. The marine layer will rebuild much shallower so
that coastal clouds are restricted to areas near the coast and
only during nights and mornings. Each day will be warmer than the
previous day with temps across the region rising to above average
by Thursday. It could get pretty hot inland next weekend or temps
could be closer to seasonal averages, depending on which model
verifies better.
&&
.AVIATION...
092009Z...Coast/Valleys...Through 10/0000 UTC, primarily P6SM vis
and FEW clouds AOA 20000 ft msl. 10/0000-1500 UTC, OVC stratus re-
developing and filling the coast and valleys, with bases 1500-2200
ft msl, tops around 2500 ft msl, and areas of vis 3-5 sm over the
valleys. Forecast confidence is moderate.
Mountains/Deserts...P6SM vis and FEW clouds AOA 20000 ft msl through
Saturday morning. After 10/0000 UTC, W winds 15-25 kt with gusts 35
kt over mountain ridges, desert slopes, through passes and into wind-
favored adjacent deserts will create mod-stg uddfs/llws over and E
of the mountains.
&&
.MARINE...
A trough will be moving inland along the U.S. West coast through
Monday which will result in an increase in northwesterly winds. HRRR
shows wind gusts to increase into the 20-25 KT range beyond 20 nm
off the coast late this afternoon through this evening. A Small
Craft Advisory is in effect through Midnight tonight. Winds relax a
tad overnight into Saturday before picking back up again late
Saturday and then strengthening further Sunday into early Monday
when another advisory for hazardous small craft conditions may be
needed for the outer waters.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory until midnight PDT tonight FOR Waters from
San Mateo point to the Mexican Border Extending 30 to 60 nm
out including San Clemente Island.
&&
$$
PUBLIC...PG
AVIATION/MARINE...Harrison