Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/08/16
Area Forecast Discussion
National Weather Service Wakefield VA
1009 PM EDT Fri Oct 7 2016
.SYNOPSIS...
Hurricane Matthew is forecast to lift along the Southeast coast
through Saturday night. A cold front will cross our region
Saturday night and steer Matthew east and away from the coast
through Sunday. Cool high pressure then builds in from the
northwest early next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Latest IR satellite imagery depicts warming cloud tops over the
local area, downstream of Hurricane Matthew. This matches well
with diminishing light precip. Model soundings and RAP guidance
indicates some drier air working into the low levels this evening,
which has helped erode the light rain. Have trended POPs westward
tonight, but will keep chance POPs into central Virginia though
around 08/06Z. Rain chances begin to increase from SW to NE after
06Z as the moisture from Matthew begins to edge north. Will have
likely pops or better (>55%) along/south of the I-64 corridor by
12Z Sat. Mostly cloudy/overcast through tonight with lows in the
60s to near 70.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Hurricane Matthew slides N/NE along or just off the NC/SC coasts
Sat into Sat night with widespread rainfall occuring across the
FA. With the storm staying south of the local area, the main land
impacts from Matthew will be heavy rain/gusty winds SE and tidal
flooding along the coast. Refer to the Tides/Coastal Flooding
section below for more on that. The heaviest rainfall continues to
be expected Sat aftn into early Sun morning across SE VA into NE
NC, where a flash flood watch remains in place. Will add another
row of counties to the north of the previous watch (which will
now include the lower Peninsula). Storm total QPF amounts have
changed very little with the most recent model runs, and
therefore will continue to show 1-2" across far southern VA, 2-4"
of rain across the Tidewater/SE VA and 3-7" across NE NC with
locally higher amounts possible near the Albemarle Sound. The rain
will end from west to east late Sat night/Sun morn, except
lingering until late Sun aftn along the SE coast, as a cold front
crosses the area. Clouds will decrease from west to east on Sunday
as well. Winds will be strongest over SE portions of the FA
beginning Sat eve, spreading NE into areas adjacent to the Ches
Bay/lower Eastern Shore coastal waters on Sunday. Peak wind gusts
are expected to reach 35-45 mph...and up to 50 mph VA Beach/Outer
Banks Currituck. Will go head and issue a Wind Advisory for the VA
Tidewater into NE NC this afternoon. This will likely need to be
extended northward along the Ches Bay/lower VA Eastern Shore by
Sat morn. High pressure begins to build into the area Sunday night
thru Monday for dry wx all areas and a mainly clear sky (some
additional clouds linger along the coast). A tight pressure
gradient will linger Sun aftn into Monday, especially along the
immediate coast where winds will remain elevated. Highs Sat upr
60s NW to mid 70s SE. Lows Sat night in the mid 50s to mid 60s.
Sunday/Monday highs in the 60s to near 70. Please refer to the
National Hurricane Center for the latest information on Matthew.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The long term period Monday night through Friday will be mainly dry
and relatively uneventful. A strong surface high will be firmly in
control on Tuesday extending from a center near Maine with a ridge
reaching southwest into the Gulf Coast States. Tropical Cyclone will
be weakening well to the east of Florida. The high retreats around
midweek and a cold front moves through from the west around
Thursday.
High temperatures in the upper 60s to lower 70s warm to the mid to
upper 70s Wednesday and Thursday then cools a few degrees on Friday.
Low temperatures in the mid 40s in the Piedmont to the mid and upper
50s southeast Tuesday morning will range through the 50s to near 60
Wednesday through Friday mornings.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Onshore flow persists over the region with a weak coastal trough
located over the coastal plain. Light rain/drizzle continues
across southern Virginia into northeast North Carolina. Expect the
TAF sites to remain dry for the next several hours. Northeast
winds have diminished at or below 10 knots. MVFR/locally IFR
conditions over the Piedmont into central Virginia will push
eastward overnight tonight, reaching all but KSBY by 09-11Z
Saturday. Scattered light rain or drizzle possible through the
overnight, but the best coverage expected over the Piedmont.
For Saturday, Matthew continues to lift slowly along the Southeast
coast as high pressure retreats northeastward. Widespread precip
is expected to reach northeast North Carolina and southeast
Virginia early Saturday morning, and overspreading the area
through mid to late morning. Heavy rainfall is expected across the
southeast local area, reducing visibilities to IFR at times.
Ceilings expected to be MVFR all sites (late Saturday for KSBY).
Northeast winds increase to 15 to 20 knot with gusts to 30 knots
southeast Virginia/northeast North Carolina. Elsewhere...10 to 15
knots.
OUTLOOK...Rain continues Saturday night which will be heavy at
times mainly southeast portions. Periods of IFR will be possible.
The weather improves slowly from northwest to southeast Sunday
with rain ending southeast portions in the afternoon. High
pressure and fair weather returns Sunday night through mid week.
&&
.MARINE...
Latest position of Hurricane Matthew has it just E of KJAX at of
21z. On the latest NHC forecast track, expect Matthew to lift off
to the N/NE along or just off the FL/GA coast early tonight, and
to the GA/SC coast by late tonight. With the storm staying south
of the local area, the main land impacts from Matthew will be
heavy rain SE and gusty winds/tidal flooding along the coast (See
coastal flooding section below). Onshore E-NE flow will continue
tonight as the inverted coastal trough pivots offshore this
evening. SCA for New Point Comfort to Little Creek drops off early
this evening, with winds briefly diminishing early tonight as
gradient slackens. SCA flags mainly for hazardous seas continue
flying through the night along the coastal zones and the mouth of
Chesapeake Bay. Seas 4-6ft (highest south), waves 2-3 ft, except
3-5 ft in the mouth of the Bay. Seas ramp up a bit late across the
southern waters, as wind wave from Matthew arrive late tonight.
Seas quickly ramp up well offshore late tonight and Saturday. Seas
Saturday increase to 6-8ft over southern waters by late tomorrow
morning.
Matthew will lift NNE to a position along and just off the NC/SC
coast on Saturday and Saturday night, with dangerous navigating
conditions across the waters through the weekend w/widespread
rainfall and gusty winds across the marine area. Given that Matthew
is expected to stay to the south, strongest winds are expected after
sunset Saturday night and through Sunday in strong cold air
advection behind strong cold front, as strong 1030+mb sfc high
pressure builds over the upper midwest into the interior northeast.
Deterministic models and their member ensembles show a likely period
of gales over most of the marine area late Saturday night through
early Sunday night on strong NNE winds. Winds average 25-30kt over
northern waters to 30-35kt S Sat night and Sunday. Gusts to 35-45kt
possible, and potential for a period of low end Storm (in excess of
45kt possible) s of Cape Charles. Have not gone with any storm
mention at this point with lower probabilities indicated. However,
did issue a Gale Watch for all zones starting Saturday night, again
with a high likelihood of gale conditions across much of the waters.
For the sake of simplicity at this stage, have run through midnight
Sunday/early Monday, but latest ECMWF indicates Gale may linger over
far southern areas into Monday morning. After Gales come down, SCA
conditions should persist for much of early next week for the ocean
for hazardous seas, with a NE wind gradually diminishing as high
pressure builds into the region from the north as coastal trough
remains aligned offshore.
&&
.TIDES/COASTAL FLOODING...
Tidal departures continue to trend downward w/most sites now just
below minor flood thresholds with the exception of near Jamestown,
which is currently dropping below minor thresholds at this hour.
Advy for Jamestown area has been allowed to expire. A continued
modest improvement is expected tonight/overnight into Saturday
before anomalies trend back up later Saturday and Sunday, and
another round of Coastal Flood headlines are likely to be needed.
Regardless of the track of Matthew, strong northerly winds are
expected to develop late Saturday into Sunday night with
tightening pressure gradient between high pressure to the north
and the tropical cyclone Matthew to the south. Latest ESTOFS/ETSS
each depict the potential for 2.0-2.5ft tidal anomalies late
Saturday night into Sunday from the lwr Bay to coastal se VA/ne
NC. This has the potential to produce high end minor to moderate
coastal flooding from the lwr Bay to the nrn Outer Banks.
High seas will build to 8-10ft nearshore by Saturday night...have
issued High Surf Advisory for VA Beach/Northern OBX. Will likely
need to add Eastern Shore Atlantic coastal zones with forecast
issuance late tonight or tomorrow, with seas likely building
across northern zones later Sun into Monday.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...Flash Flood Watch from 4 AM EDT Saturday through Sunday
afternoon for NCZ012>017-030>032-102.
Wind Advisory from 6 PM Saturday to 2 PM EDT Sunday for
NCZ012>017-030>032-102.
High Surf Advisory from 8 PM Saturday to 6 AM EDT Monday for
NCZ102.
VA...Flash Flood Watch from 4 AM EDT Saturday through Sunday
afternoon for VAZ087-092-093-095>098-524-525.
Wind Advisory from 6 PM Saturday to 2 PM EDT Sunday for VAZ087-
092-093-095>098-524-525.
High Surf Advisory from 8 PM Saturday to 6 AM EDT Monday for
VAZ098.
MARINE...Gale Watch from Saturday evening through Sunday evening for
ANZ630>638-650-652-654-656-658.
Small Craft Advisory until 6 PM EDT Saturday for ANZ634-650-
652-654-656-658.
Small Craft Advisory until midnight EDT tonight for ANZ632.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...JDM/MAS
LONG TERM...MAM/LSA
AVIATION...SAM/LSA
MARINE...MAM
TIDES/COASTAL FLOODING...
Area Forecast Discussion...Updated
National Weather Service Billings MT
905 PM MDT Fri Oct 7 2016
.UPDATE...
Shower activity is decreasing across the area but a few light
showers should be expected. The HRRR has followed this trend and
backed off the amount of activity it was progging compared to
earlier runs. Winds at KLVM are weakening as the leeside trough is
pulling a bit eastward. No updates. dlb
&&
.SHORT TERM...valid for Sat and Sun...
A zonal flow regime aloft will spread periods of clouds across the
area through the weekend, but downslope winds with this pattern
will produce mainly dry and warmer conditions.
Tonight...Pacific jet supports a disturbance crossing the area
this afternoon through late tonight. Residual low level moisture
combined with a strong fetch of moisture with the jet stream will
bring isolated to scattered showers to western and northern zones.
Any precipitation will be light with this activity. Stronger winds
off the surface should limit any overnight fog formation tonight.
Lows tonight will be in the 35 to 45 degree range overnight.
Saturday/Sunday...Jet stream shifts just a bit north of the area
for more sunshine this weekend. Winds on Saturday look fairly
light out of the south, but increase on Sunday out of the west at
10 to 20 mph. These stronger downslope winds will boost
temperatures from the 60s Saturday to the mid 70s on Sunday. Looks
like next cold front arrives Monday afternoon. Chambers
.LONG TERM...valid for Mon...Tue...Wed...Thu...Fri...
Only minor changes to the extended forecast this afternoon. Model
agreement through the period appears to be greatly improved from
24hrs ago. That said ensemble spreads for temps increase
significantly after midweek.
Temps will trend downward Monday and Tuesday...as quick moving
clipper system pushes through the region. Warmup for Monday will
be limited by FROPA...especially for northern tier, where temps
will struggle to reach 60s. Highs in the 40s are expected for
Tuesday. This system will bring precip chances across the
region...as northerly flow produces shallow upslope on north
facing slopes of the Beartooths and Pryors, and some degree of low
level of frontogenesis over the plains. Ridging builds into the
area by Wednesday...beginning a warming trend. The ridge remains
in control over the region into Thursday. Weak shortwaves begin to
break down the ridge Thursday afternoon...with flow becoming more
zonal by Thursday night. Dry conditions should limit any
development to western high terrain through the day Thursday...but
did extend pops across the region for Friday...with stronger
energy...and improved moisture availability. Highs will climb back
into the mid 60s for Thursday and Friday....with Friday looking to
be the warmer day with support of downslope winds. AAG
&&
.AVIATION...
VFR conditions will prevail across the area tonight through
Saturday. A few showers will move across the area during the
night, but should not lower conditions. Gusty WSW winds at KLVM
will diminish overnight. Arthur
&&
.PRELIMINARY POINT TEMP/POPS...
Sat Sun Mon Tue Wed Thu Fri
-----------------------------------------------------------
BIL 044/066 048/075 049/065 036/044 036/057 044/065 049/067
11/B 00/U 01/N 22/W 00/U 00/B 12/B
LVM 043/068 047/074 047/065 037/051 036/060 041/065 045/064
21/N 10/N 11/N 22/W 10/B 02/W 22/W
HDN 042/067 044/078 044/067 036/045 034/057 041/065 047/068
11/B 00/U 01/B 22/W 00/U 00/B 12/B
MLS 039/061 045/077 045/062 035/044 033/055 041/064 047/070
21/U 10/U 01/B 22/W 10/U 00/B 11/B
4BQ 041/065 044/078 044/072 036/044 034/059 041/067 046/073
11/B 10/U 01/U 22/W 00/U 00/B 11/B
BHK 034/058 041/074 044/063 032/042 030/052 038/062 044/070
10/U 10/U 01/B 32/W 10/U 00/B 11/B
SHR 040/066 043/076 045/072 037/046 034/060 041/067 045/068
11/U 00/U 01/U 22/W 10/U 00/B 12/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service State College PA
1131 PM EDT Fri Oct 7 2016
.SYNOPSIS...
Rain will begin over the western highlands this evening as a a
cold front moves in from the west tonight. The front will pass
through the region during the day Saturday. Cooler and drier
weather is expected into early next week before a new but mainly
dry cold front approaches Thursday. Hurricane Matthew will remain
off the southeastern US coast and not directly impact our weather.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Tropical plume of moisture lifting into southwest PA ahead of 5h
shear axis lifting northward is bringing light showers from the
Laurel Highlands to the North Central Mountains late this
evening. The eastern periphery of this activity is just light
sprinkles and cuts off over northern portions of the central
mountains.
Deep layer moisture will continue to slowly increase overnight
as southerly flow aloft between approaching Glaks trof and
offshore ridge directs it northward. Forcing remains rather
weak...and so showers will be most favored over the higher
terrain...but expect a gradual eastward progression to shower
chances as 1 to 1.5" PW increase late tonight into Saturday
morning.
Expect increasing low clouds and fog after midnight in the NW
two-thirds of the area. Steady rain will likely take all night to
get past UNV and may not get to IPT before sunrise. The cold front
should be almost to Warren Co by sunrise. The QPF from the SREF
plumes is very widely dispersed, but the median & mean look close
and also close to the oprnl models. Up to an inch is possible in
the Alleghenies, esp the Laurels. Muggy and mild overnight in the
east.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
The front will move across the area Saturday as a weakening
feature. The band of rain before the front is likely going to
weaken as the front nears, with little moisture left for the
front to lift as it goes by. After a very dismal start to the day
- the NW will brighten nicely during the morning. It will take
much of the aftn for the rain to push east of the central mtns,
and another few hours to clear out. If the clearing happens before
sunset, the high ambient moisture may lead to very a foggy Sat
night. If clearing happens later, widespread fog is not likely.
But, it will almost certainly happen in ye olde valleys of the
north and west. Maxes in the 60s will be just a shade above
normal.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Any lingering showers will exit eastern Pennsylvania Saturday
night. Cold, dry air will advect into the area behind the front.
High pressure will build in behind the front and bring a period
of tranquil but cool weather that will last into the midweek. The
cold air will continue to filter in as the northwesterly flow
continues into Monday morning. This cold air advection could allow
for the first real chance for widespread frost of the season
Sunday night into Monday morning. Models continue to show 850
temps nearing zero with anomalously dry air and light wind
setting in. The main area of concern in through the Northern half
of Central Pennsylvania.
The only possible complication in the medium range could be for
the potential of low clouds returning in a developing maritime
flow by later Tuesday into Wednesday.
The next front is made to approach later Wednesday into Wednesday
night, with another chilly chunk of air expected to follow for
the last days of the work week. The GEFS and EC have significant
timing and placement differences for any significant confidence.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
A plume of tropical moisture streaming up the Appalachian
Mountains is supporting a band of steady rain tonight from KBFD
to KJST. The moist southeast flow ascending the higher terrain of
Central Pa is already resulting in IFR cigs in the vicinity of
KBFD/KJST at 0330Z. Model soundings and latest HRRR support the
idea of IFR cigs also developing at KAOO and KUNV overnight. The
lower elevation airfields further east are likely to experience a
dry night. However, MVFR cigs appear possible late tonight
associated with moistening southeast flow. Not giving much
credibility to the HRRR producing fog at KMDT/KLNS after midnight,
given the amount of high clouds and substantial dwpt depressions
going into the evening.
Low cigs and showers appear likely across the Central Mtns into
early Saturday afternoon associated with slow moving cold front,
then some modest improvement is possible late in the day, as drier
air arrives. Across the eastern airfields from KIPT south through
KMDT/KLNS, it looks like MVFR conditions will predominate for much
of the day, with morning cigs in the 1-3KFT range, followed by
scattered rain showers with arrival of front in the afternoon.
Outlook...
Sun...No sig wx expected.
Mon...AM fog possible KBFD.
Tue-Wed...Patchy AM fog possible.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Dangelo
NEAR TERM...Dangelo/DeVoir
SHORT TERM...Dangelo
LONG TERM...La Corte/Ceru
AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
651 PM CDT Fri Oct 7 2016
.UPDATE...
00Z Aviation Update Below.
&&
.AVIATION...
The main cold front has caught up with the earlier wind shift this
afternoon, and is now located just south of a DRT-SAT line.
Scattered SHRAs and TSTMs will continue south of DRT over the
next hour or two. IFR/MVFR ceilings prevail over the Hill Country
early this evening, and HRRR guidance suggest these ceilings will
remain over this region into the late evening and not impact AUS
or SAT. HRRR and NAM12 BUFR soundings do suggest BKN MVFR ceilings
developing up the Rio Grande at DRT later this evening, and have
included mention in the DRT 06Z-12Z. N winds at AUS/SAT/SSF gusty
through the evening hours, with gusts 18-22 kts possible, before
settling down after midnight. Similar gusts from the NW at DRT but
may diminish sooner.
&&
.PREV DISCUSSION... /ISSUED 235 PM CDT Fri Oct 7 2016/
SHORT TERM (Tonight through Saturday Night)...
The cold front continues to push into South-Central Texas this
afternoon. At 2 PM the initial wind shift was located near the
I-10 corridor with the actual cooler temperatures lagging a bit
farther behind. Scattered convection continues as well along the
boundary and this will continue through the early evening hours
with the best chances of showers and storms moving south and
southwest over the next several hours as the front continues to
move. Things will clear out after this evening with partly to
mostly cloudy skies continuing. Lows tonight will be much cooler,
bottoming out in the middle 50s to middle 60s. Tomorrow should be
mostly quiet with partly to mostly cloudy skies continuing. Highs
will top out in the upper 70s to upper 80s.
LONG TERM (Sunday through Friday)...
A surge of drier air is expected to move in from the northeast on
Sunday. This push of dry air will be funneled to the southwest
between surface high pressure in the Central Plains and the
surface low associated with Hurricane Matthew just off the coast
of the Carolinas. Dewpoints on Monday morning will likely be 40s
across much of the area. This will lead to the coolest night of
the year so far with lows Monday morning in the upper 40s for some
of the area. With the dry air in place, we should see high
diurnal ranges in temperatures Monday through Wednesday with cool
nights and warm afternoons in the middle 80s. Moisture values will
increase slightly by the end of the forecast period leading to
lows back into the lower to middle 60s. No rain additional rain is
expected through next Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 61 84 62 84 52 / - 0 - 0 0
Austin Bergstrom Intl Airport 58 84 59 83 49 / - 0 - 0 0
New Braunfels Muni Airport 62 85 61 85 51 / 10 0 - 0 0
Burnet Muni Airport 57 80 58 80 50 / - 0 - 0 0
Del Rio Intl Airport 64 80 65 84 60 / 20 10 - 0 0
Georgetown Muni Airport 59 82 57 82 49 / - 0 - 0 0
Hondo Muni Airport 63 87 63 87 53 / 10 0 - 0 0
San Marcos Muni Airport 62 83 61 83 51 / 10 0 - 0 0
La Grange - Fayette Regional 62 86 61 83 52 / - 0 - 0 0
San Antonio Intl Airport 65 85 63 84 53 / 10 0 - 0 0
Stinson Muni Airport 66 86 65 86 54 / 10 0 - 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...Runyen
Synoptic/Grids...Treadway
Area Forecast Discussion
National Weather Service Omaha/Valley NE
631 PM CDT FRI OCT 7 2016
.SHORT TERM...(Tonight through Monday)
Issued at 250 PM CDT Fri Oct 7 2016
The main forecast concerns in this period are potential for
patchy frost tonight...mainly in our northern zones - and
precipitation chances from Sunday night into Monday.
Water vapor and IR satellite imagery early this afternoon in
combination with recent RUC model initializations showed fairly
quiet weather in our area behind the system that moved through
yesterday. A 100 knot jet max at 300 mb was noted over the Pacific
Northwest ar 12z, associated with a disturbance there. There was
also a disturbance noted moving into southern California. At the
surface...high pressure was noted over the region.
That high pressure will move east/southeast tonight. By sunrise
Saturday, the axis of the high should extend from western Oklahoma
into southeast Minnesota. Our area will be in southerly return
flow, which is expected to develop latest in our far northern
counties. Will mention some patchy frost mainly there, and also in
parts of western Iowa north of Interstate 80.
Southerly flow should bring in some warmer air for Saturday, and
with lots of sunshine we look for highs in the upper 60s and lower
70s. A weak cold front will try to push into our area from the
north Saturday night but then start to lift back north Sunday.
Highs Sunday should be in the lower 70s at most locations.
Southerly flow will strengthen a bit Sunday night into Monday,
bringing in a little more low level moisture and some instability.
Some energy aloft associated with a weak trough will move in from
the west/southwest, so some isolated showers and thunderstorms
appear possible.
.LONG TERM...(Monday night through Friday)
Issued at 250 PM CDT Fri Oct 7 2016
At the start of this period, there will be a blocking ridge in the
mid troposphere from just off the Pacific Northwest coast up into
the Yukon. That should help funnel some colder air from Canada down
into the Northern and Central Plains for Wednesday and Thursday.
The mid level ridge should break down by late in the week...with
temperatures moderating back closer to normal by Friday.
Opted to go with a dry forecast for Monday night but there may be
some isolated activity ahead of the front. Will keep an eye on
that for later forecasts. Did include some low rain chances later
in the week (Tuesday night into Wednesday) and then again from
Thursday into Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 629 PM CDT Fri Oct 7 2016
VFR conditions under clear skies are forecast through Saturday
afternoon. Low level wind shear is likely at KOFK from 09Z to 15Z
when southwest winds average 40kt at FL020. Light winds overnight
will become south to southwest at 12kt by 18Z.
&&
.OAX Watches/Warnings/Advisories...
NE...None.
IA...None.
&&
$$
SHORT TERM...Miller
LONG TERM...Miller
AVIATION...Dergan
Area Forecast Discussion
National Weather Service Buffalo NY
416 AM EDT Sat Oct 8 2016
.SYNOPSIS...
A cold front will move across Western NY this morning with a few
scattered showers. A plume of sub-tropical moisture will bring
steadier rain to Central New York and the eastern Lake Ontario
region. All of the rain will end from west to east later today with
the passage of the cold front. Much cooler air will then move into
the region for Sunday and Monday. A few scattered lake effect rain
showers are possible Sunday southeast of the lakes. High pressure
will then bring a return to dry weather for the first half of next
week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Radar imagery showing a band of steady, moderate rain moving north
through the Finger Lakes and spreading into the eastern Lake Ontario
region early this morning. This area of rain is in association with
a narrow plume of sub-tropical moisture and associated modest 30
knot low level jet extending well north of Hurricane Matthew. Short
term high resolution guidance such as the HRRR is handling this
scenario well, and suggest the steadier rain will last across
Central NY and the eastern Lake Ontario region through mid to late
morning before becoming more intermittent in nature.
Meanwhile a few scattered showers are also found upstream across
southern Ontario just ahead of a surface cold front. These scattered
showers will cross Western NY this morning as the cold front
approaches, but coverage and amounts will remain very sparse
compared to points farther east. As the cold front catches the plume
of sub-tropical moisture across the eastern Lake Ontario region, it
will force additional showers to develop during the midday and
early afternoon hours.
Much drier air will advect into the region behind the cold front,
with a return to sunshine this afternoon across Western NY. Clouds
will be slower to clear east of Lake Ontario, but even here a few
breaks in the clouds may develop late in the day. High temperatures
will reach the mid 60s in most areas through the first half of
today, then begin to pull back later this afternoon as moderately
strong cold advection develops behind the front.
Any breaks in the clouds this evening will gradually fill in again
overnight as chilly northwest flow becomes established and promotes
lake effect and upslope cloud development. Lake induced equilibrium
levels rise to around 8K feet, only marginally supportive of any
lake effect rain showers. Further limitations will be a short
northwest fetch, limited background synoptic scale moisture, and a
stout inversion above 8K feet. Thus expect just a few scattered
showers overnight. Off Lake Erie any showers will be directed across
the Chautauqua Ridge. Showers off Lake Ontario will be found from
the Rochester area east to Oswego County and southward into the
Finger Lakes.
Steady cold advection will bring lows into the mid 40s on the lake
plains by daybreak Sunday, with lows around 40 across the interior
Southern Tier and Lewis County.
&&
.SHORT TERM /SUNDAY THROUGH WEDNESDAY/...
On Sunday, an upper level trough will be crossing the lower Great
Lakes with cold air advection in place behind the associated surface
cold front. 850 mb temperatures will drop to about 0C by Sunday
morning, which will warrant a weak lake effect response in the short
northwest fetch and limited synoptic moisture. Widely scattered rain
showers will develop southeast of Lake Ontario and Lake Erie in the
northwesterly flow. As the upper level trough pivots across the
region during peak diurnal heating, the resultant steepening lapse
rates across the region and an upstream Georgian Bay connection may
help scattered rain showers develop across the Niagara Frontier and
drop southward across western NY as the flow pivots more northerly
behind the trough passage by Sunday afternoon and evening. Showers
will taper off Sunday evening in the increasing subsidence and drier
air behind the trough passage, with some lingering scattered lake
cloudiness. Normal high temperatures for this time of year are in
the low 60s, and we will finally see a day close to, if not slightly
below, normal this fall as high temperatures top out in the upper
50s to near 60. High pressure will build across the lower Great
Lakes through Sunday night, giving way to clearing skies and
diminishing winds. Low temperatures will bottom out near freezing in
the interior portions of the Southern Tier and the North Country,
while the lake plains remain more mild in the upper 30s to lower
40s.
High pressure will then remain over the lower Great Lakes and into
New England through Monday night. Any lingering lake effect
cloudiness from Sunday will be a distant memory by Monday as
abundant sunshine will prevail across the region. Highs on Monday
will remain near normal in the upper 50s to lower 60s under the
surface high. Another chilly night will be in store Monday with more
optimal radiational cooling conditions in place.
Tuesday and Wednesday will both be fantastic days across the region
with building warmth and just some increasing mid and high level
cloud cover. The surface high will slide off the New England coast,
as deep southwesterly flow develops over the Great Lakes. The
result will be the return of warmer air, pushing 850 mb temperatures
back to around +10C and giving daytime highs in the mid to upper
60s. 850 mb temperatures push just a bit higher on Wednesday (to
around +11/+12C) resulting in afternoon highs in the upper 60s to
low 70s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Global models are in good agreement with the timing of a weak trough
that tracks from high plains to the upper Great Lakes on Wednesday,
and lifts across Ontario by Wednesday night. The weak, positively
tilting trough will drag a weak surface cold front across the region
Wednesday night into Thursday, which will result in some widely
scattered showers with the frontal passage. A large surface high
will the build across the region for the end of the week and into
the weekend resulting in more near-normal temperatures and fair
weather.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
A narrow plume of tropical moisture will continue to stream
northward through the Finger Lakes and Central NY through this
morning with periods of rain and associated MVFR and brief IFR VSBY.
A cold front approaching from the west will bring a few scattered
light showers to Western NY this morning, then sweep east with rain
ending from west to east during the day.
CIGS are already deteriorating to MVFR and IFR across the Southern
Tier, and these lower CIGS will continue to spread north and east
through this morning. High resolution model guidance suggests a
subtle IFR event at KBUF and KIAG as the cold front approaches and
picks up moisture off Lake Erie, producing a plume of IFR stratus
northeast of the lake. During the afternoon CIGS will improve
following the cold frontal passage as dry air sweeps into the area,
with conditions returning to VFR from west to east.
Tonight a northwest flow of chilly air will allow some lake effect
and upslope clouds to develop, with these clouds reaching a maximum
of coverage around daybreak Sunday. CIGS will be a mix of lower end
VFR and MVFR in the lake effect clouds. A few widely scattered lake
effect showers are also possible southeast of the lakes overnight.
Outlook...
Sunday...areas of MVFR with a chance of lake effect rain showers
southeast of the lakes.
Monday through Wednesday...VFR.
&&
.MARINE...
A cold front will move across the Lower Great Lakes today. Southerly
winds ahead of the front will continue to produce Small Craft
Advisory conditions this morning at the northeast end of Lake
Ontario. Winds will become westerly behind the front this afternoon,
with Small Craft conditions developing on the rest of Lake Ontario
and also Lake Erie.
Winds will diminish later this evening on Lake Erie, while Small
Craft advisory winds and waves continue on Lake Ontario through
early Sunday morning. Another brief period of stronger winds and
waves may develop on Lake Ontario Sunday night as northeast winds
increase. High pressure will then bring a return to lighter winds
for the first half of next week.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 11 PM EDT
this evening for LEZ040-041.
Small Craft Advisory from 2 PM this afternoon to 8 AM
EDT Sunday for LOZ042>044.
Small Craft Advisory until 8 AM EDT Sunday for LOZ045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...CHURCH
LONG TERM...CHURCH
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
Area Forecast Discussion
National Weather Service State College PA
525 AM EDT Sat Oct 8 2016
.SYNOPSIS...
A cold front will move through the area today. Cooler and drier
weather is expected into early next week before a new but mainly
dry cold front approaches Thursday.
Hurricane Matthew will remain off the southeastern US coast and
not directly impact our weather.
&&
.NEAR TERM /THROUGH TONIGHT/...
Though the center of Hurricane Matthew will not come close to
central Pa, the storm is being generous in sharing some of its
deep tropical moisture that will continue lifting north into the
region ahead of an approaching cold front. Water Vapor loop shows
the storm spinning off the Ga/Sc border with the moisture plume
surging northward up through Pa into upstate NY.
HRRR timing shows the band of rain marching steadily east today
with the highest chances for rain early over my western zones,
moving into my central zones by mid to late morning and finally
into my eastern zones by early to mid afternoon. The front will
lag this rain so even behind the main band of rain, we will stay
vulnerable to scattered showers over most of the area well into
the afternoon.
I used a model consensus for QPF which shows amounts around 1/3
inch over eastern areas, building up to a little over an inch in
the Laurel Highlands.
Highs today will rise into the low to mid 60s, which will be very
close to normal for early October.
Skies will become clear to scattered from west to east later today
and overnight. It should stay a bit on the breezy side so I didn`t
include any fog at this time. But if the winds drop off, Sunday
could start rather gloomy.
Overnight lows will drop to around 40 over the north, to around 50
in the southeast.
&&
.SHORT TERM /SUNDAY/...
Short range guidance suggests the cold front will hang up just off
the coast Sunday. Some guidance shows the chance of rain lingering
over my far sern zones. I used the normally wet SREF pops which
in this case, keeps the region dry tomorrow.
The upper shortwave could trigger a light shower over the NW
mountains as well, but MOS pops are very low there as well so I
chose to mention just a sprinkle, and no measurable rain.
Highs Sunday will range from the mid 50s to low 60s, averaging
about 4-8 deg below normal.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
High pressure will build into the region to start the new work
week and bring a period of tranquil but cool weather that will
last into the midweek. Monday morning will start on the chilly
side with perhaps the first widespread front of the season over
much of northern Pa. as models advertise 850 temps nearing zero
with anomalously dry air and light surface wind setting in.
The next front is now delayed until Wednesday night into
Thursday, with another chilly chunk of air expected to follow for
the last days of the new week. Pretty uneventful overall.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
09Z TAFS sent.
A plume of tropical moisture streaming up the Appalachian
Mountains is supporting a band of steady rain early today from
KBFD to KJST. The moist southeast flow ascending the higher
terrain of Central Pa is already resulting in IFR cigs in the
vicinity of KBFD/KJST at 0330Z. Model soundings and latest HRRR
support the idea of IFR cigs also developing at KAOO and KUNV
overnight. The lower elevation airfields further east are likely
to experience a dry night. However, MVFR cigs appear possible late
tonight associated with moistening southeast flow. Not giving much
credibility to the HRRR producing fog at KMDT/KLNS after midnight,
given the amount of high clouds and substantial dwpt depressions
going into the evening.
Low cigs and showers appear likely across the Central Mtns into
early Saturday afternoon associated with slow moving cold front,
then some modest improvement is possible late in the day, as drier
air arrives. Across the eastern airfields from KIPT south through
KMDT/KLNS, it looks like MVFR conditions will predominate for much
of the day, with morning cigs in the 1-3KFT range, followed by
scattered rain showers with arrival of front in the afternoon.
Outlook...
Sun...No sig wx expected.
Mon...AM fog possible KBFD.
Tue-Wed...Patchy AM fog possible.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...La Corte
LONG TERM...La Corte
AVIATION...Fitzgerald/Martin
Area Forecast Discussion
National Weather Service Duluth MN
403 AM CDT SAT OCT 8 2016
.SHORT TERM...(Today through Sunday)
Issued at 403 AM CDT Sat Oct 8 2016
At 403 AM, skies were clearing across portions of the Northland.
After a night of cloudy skies, skies were clearing in the Brainerd
Lakes Area, and along the North Shore of Lake Superior.
Temperatures ranged from the lower 30s in the southwest to around
40 in portions of northwest Wisconsin.
The main focus for this weekend will be cloud cover and
temperatures. The clouds should continue to decrease from west to
east across the Northland today, although more high clouds will
spread in from the west. The result will be a partly sunny sky for
most areas, although areas of clouds will linger in some
locations. High temperatures will definitely be on the cool side,
with highs ranging from the mid 40s to the lower 50s. We should
see areas of frost early this morning, especially along and south
of the Highway 2 corridor.
It looks like we will see another night of frost and freeze
conditions tonight, as temperatures fall into the lower 30s. Some
typically colder locations could see temperatures drop into the
upper 20s. As a result, we may need frost and/or freeze headlines
once again for the upcoming night.
Southerly winds will bring warmer air back into the Northland on
Sunday. Temperatures will generally be in the 50s under partly
sunny skies.
.LONG TERM...(Sunday night through Friday)
Issued at 403 AM CDT Sat Oct 8 2016
The main concerns for the long term include temperature trends
and the potential for rain and thunderstorms Tuesday and Tuesday
night.
A quasi-zonal flow will continue to build across the Northern
Plains Sunday night. Surface high pressure will depart to the east
overnight with a south to southwesterly return flow developing. A
positively tilted longwave trough will dig across the Rockies and
into the Great Plains Monday afternoon. An elongated surface low
will develop in the lee of the Rockies in response to falling
heights and approaching cyclonic vorticity with a cool front
advancing east across the Dakotas and Canadian Prairie Provinces.
The southwest flow will pull two separate moisture streams
northward into the region ahead of the system. Even with meager
moisture, there should be sufficient lift along and ahead of the
front for showers and a few thunderstorms late Monday night
through Tuesday.
Colder air will return behind the front beginning Tuesday morning
in the northwest, with temperatures dipping below normal once
again through Wednesday. High pressure will build across the
region Tuesday night and Wednesday leading to fairly quiet
conditions. Quiet weather will continue Thursday and Friday as
another round of quasi-zonal flow returns. Temperatures will trend
gradually warmer, back to near or slightly above normal, by
Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 102 AM CDT Sat Oct 8 2016
Elongated trough of low pressure remained in place over the area
early this morning. Cyclonic flow and weak cool air advection will
continue through early evening with VFR/MVFR ceilings expected
until around 14Z. With gradually warming surface temperatures
after sunrise, expect MVFR ceilings to develop at remaining
airports thanks to weak instability and low level moisture. The
ceilings will gradually increase as temperatures warm through the
day for most sites. A few rain showers may pass over the terminals
at times during this forecast period, especially INL between now
and sunrise. Low-level wind shear is a concern at DLH/HYR/BRD as
surface winds continue to decouple. KDLH VAD wind profile indicates
500 meter winds of 310 at 32kt, which is right on the threshold
for LLWS. RAP 925 wind speeds suggest the highest wind speeds
will rotate through the trough and out of the terminals by mid-
morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 48 33 52 45 / 10 0 0 0
INL 45 26 52 46 / 30 0 0 0
BRD 48 30 56 48 / 0 0 0 0
HYR 49 30 56 44 / 0 0 0 0
ASX 51 34 54 44 / 10 0 0 0
&&
.DLH Watches/Warnings/Advisories...
WI...Frost Advisory until 9 AM CDT this morning for WIZ001>004-
006>009.
MN...Frost Advisory until 9 AM CDT this morning for MNZ018-025-026-
033>038.
LS...Small Craft Advisory until 10 AM CDT this morning for LSZ121-140-
141-146>148.
&&
$$
SHORT TERM...DAP
LONG TERM...Huyck
AVIATION...Huyck
Area Forecast Discussion
National Weather Service North Platte NE
309 AM CDT Sat Oct 8 2016
.SHORT TERM...(Today and tonight)
Issued at 309 AM CDT Sat Oct 8 2016
Today and Tonight...sfc low pressure across northeast WY is progged
to move east along the SD-Neb border this morning and drop a back
door cold front into Ncntl Neb this afternoon. This could hold highs
in the 60s across Nrn Neb while Cntl and Swrn Neb rise into the 70s.
The forecast uses the bias corrected RAP and LAV data which was
cooler than the MET MAV EKDMOS and ECS guidance across northern Neb.
It also captures the cooling effect of the snow cover across the
Sandhills which still lingered in some areas Saturday afternoon.
The cloud cover on satellite across MT and the Dakotas is forecast to
move east and remain north of Nebraska. Generally clear skies are
expected today and tonight. Low pressure will deepen across the Nrn
High Plains tonight producing south winds across Wrn and North
Central Neb. A blend of the MET MAV EKDMOS and ECS guidance plus bias
correction suggested lows in the 30s to near 40.
.LONG TERM...(Sunday through Friday)
Issued at 309 AM CDT Sat Oct 8 2016
Zonal flow to prevail across the central Plains which will induce a
the development of a surface trough off the Lee of the Rockies.
Southerly flow will increase as a result and lead to breezy...but
warm conditions. The latest medium range guidance indicates
widespread 70s for highs. There remains a disorganized area of low
pressure that moves from the southern Rockies out onto the southern
Plains...which may spark off an isolated shower or thunderstorm to
our south and southeast. Weak instability is in place across our
southern zones and with forcing for ascent arriving from the south,
it is possible that our far southeastern zones see a thunderstorm
during the afternoon and evening hours.
The next system of interest rapidly advances from the Pac NW across
the northern Rockies and making the northern plains by 00Z
Wednesday. In advance of the shortwave the models suggest
southwesterly downsloping winds...which will help boost high
temperatures into the 80s Monday afternoon for most locations.
The shortwave will force a cold front across the CWA early on
Tuesday. A stark cooldown is forecast for mid-week with highest in
the 50s /north/ and lower 60s /south/. The front arrives when the
troposphere is moisture starved, thus at least initially, rain
chances are slim. The models continue to advertise sufficient
saturation when the large scale forcing associated with the
shortwave trough arrives. Will maintain slight chance to lower end
chance pops Tuesday evening into early Wednesday for much of the
forecast area.
Beyond early Wednesday the forecast is dry as forcing for ascent is
largely absent save for an unorganized shortwave passing in the
southern stream late week. Temperatures will warm once again late
week as thermal advection and rising heights build east from the
Rockies.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1115 PM CDT Fri Oct 7 2016
VFR conditions currently prevail across western and north central
NE and this is expected to continue through the TAF period. Winds
have lessen from earlier with the latest sfc plot showing several
sites with calm to light and variable winds. Elsewhere, winds
have stayed up in the far southern portions of the forecast area
with speeds of 5-8 kts still being observed. Latest satellite
imagery reveals mostly clear skies with a few high clouds coming
in from the northwest.
The main concern this package is LLWS conditions. Low-level wind
shear conditions are expected to develop near midnight as
southwest low level winds develop across southwest NE to north
central NE. Wherein for these terminals the height of the top of
the shear layer is expected to be about 1000 feet with a forecast
wind speed of 40 kts. Thus LLWS was added to the KLBF given this
combined with light to calm/variable winds that are expected. Not
anticipating LLWS conditions across the remainder of the local
forecast area so LLWS was left out of the KVTN TAF at this time.
This continues to be supported by guidance, however, this will
continued to be monitored. LLWS conditions are expected to
diminish before mid morning. Light southwest winds in the
morning hours will shift over the course of the day becoming
northerly by early afternoon. Winds are expected to stay under 10
kts sustained across much of the area tomorrow. Winds will become
easterly by the evening.
&&
.FIRE WEATHER...
Issued at 300 AM CDT Sat Oct 8 2016
Dry air in the lower and mid levels of the troposphere will combine
with warm temperatures to create near RFW criteria RH across
southwest Nebraska today and for much of the sandhills and southwest
Nebraska on Monday. Wind speeds are forecast to remain well below
criteria, but early Tuesday a cold front is slated to arrive, which
will provide for a distinct wind shift and increase in speeds.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...Jacobs
AVIATION...ET
FIRE WEATHER...Jacobs
Area Forecast Discussion
National Weather Service Marquette MI
513 AM EDT Sat Oct 8 2016
.SHORT TERM...(Today and tonight)
Issued at 511 AM EDT SAT OCT 8 2016
WV imagery and RAP analysis indicated a mid/upper level low just nw
of James Bay with troughing into the wrn Great Lakes. At the
surface, brisk wrly flow prevailed between the low near James Bay and
a ridge from Saskatchewan through srn MN. Radar and sfc obs
indicated sct lake effect rain showers over ern lake superior and
some lighter pcpn into the nw cwa supported by moderate instability
with 850 mb temps around -3C and lake temps in the 10C-14C range and
a moist 850-700 mb layer. Otherwise, IR loop showed mostly cloudy
skies across the area.
Today, 850 temps remaining around -2C will continue to provide
enough instability for sct -shra for locations favored by wrly flow.
As the low level winds gradually veer to the nw with high pres
building into the nrn Ontario, look for greater pcpn coverage into
the ern cwa this afternoon. Over the rest of the area, Fall-like
conditions with highs from the upper 40s west to the lower 50s east
under mostly cloudy skies are expected.
Tonight, winds will diminish and continue to veer to the north as
the high builds closer to the region. Even though inversion heights
drop slightly, 850 mb temps remaining in the -2C to -4C range will
bring sct -shra into much of n cntrl upper MI. Wet-bulb zero heights
suggest that the pcpn will remain as rain. Mostly cloudy skies
should keep temps from falling off too far, but mins in the lower
30s are still expected over the inland west half with readings in
the upper 30s to lower 40s near the Great Lakes.
.LONG TERM...(Sunday through Friday)
Issued at 253 AM EDT SAT OCT 8 2016
The start of the long term begins 12Z Sun with a SFC high over the
area and 850mb temps around -3C. Should see some isolated to
scattered lake effect rain showers mainly Sun morning, but can`t
rule out precip sticking around into Sun afternoon over the east.
The high moving through will switch winds around to the south from
west to east, ending the precip in that order. Upper ridging will
also moving in later in the day, bringing a warmer airmass along
with it.
The SFC high will continue to shift east while a SFC trough moves
toward the area from the west Sun night and Mon. 850mb temps
increase to around 12C by Mon afternoon. The parent upper trough for
this system will be over the Pacific NW on Mon, with potential for
some weak shortwaves and associated scattered showers to move into
the area late Mon into Tue. Main precip threat comes Tue night into
Wed morning as the upper trough approaches and the SFC trough/cold
front move through. Have high chance to likely PoPs during that time
period.
May need higher PoPs behind the cold front as models indicate 850mb
temps dropping a few degrees below 0C through Thu, but models vary
in the magnitude and duration of the colder air, as well as with
wind directions. Models do agree on a warmup late this week into the
weekend. Overall stuck close to blended guidance.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 142 AM EDT SAT OCT 8 2016
Strongest winds over 30 kts at times will be at CMX through Sat
afternoon. Expect lake effect rain showers tonight in westerly flow
at CMX. Overall tonight conditions will be MVFR due to the lower cigs
at CMX as upper level disturbance moving through enhances the lake
effect rain. Will be borderline low VFR/high MVFR at both KIWD and
KSAW through most of this forecast period.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 511 AM EDT SAT OCT 8 2016
West winds to 30 knots are expected today that will gradually veer
to the northwest. Winds will diminish to under 15kt late tonight
into early Mon as high pres moves across. SW winds will increase to
30 kts later Mon and Mon night ahead of another low pressure system
then shift to the northwest to 20-25 kts behind the system on
Tue/Wed.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...07
MARINE...JLB
Area Forecast Discussion
National Weather Service Phoenix AZ
145 AM MST SAT OCT 8 2016
.SYNOPSIS...
Scattered light showers will return to parts of Arizona today with
more thunderstorms and brief local heavy downpours and gusty winds
late this afternoon and evening. Dry conditions will return next
week with temperatures hovering well above average throughout much
of the week.
&&
.DISCUSSION...
Both WV imagery and objective analysis indicates a jet streak
punching into NW Mexico early this morning with attendant downstream
difluence and ascent spreading into southern AZ. However, backed
lower/middle tropospheric winds have been slower in advecting
sufficient moisture towards central AZ with deeper 6-7 g/kg mixing
ratios and theta-e advection still languishing in SE AZ. Both 21Z
and 03Z SREF probabilities have retreated from more bullish numbers
advertised yesterday; and most high resolution model output only
briefly develops showers within the forecast area bounds before
lifting activity north (and most concentrated through Gila County
and northern edges of Maricopa Co). Still, with the good ascent
structure entering the region and moisture not far away, feel some
measure of showers are still possible through central AZ this
morning, though pared back POPs somewhat to account for less overall
coverage.
While the reflection towards morning showers has waned somewhat in
model output, the propensity towards more extensive deeper
convection this afternoon has grown in high resolution models. There
is fair evidence that thicker high clouds will at least partially
clear today allowing better sfc insolation and MLCape around 1000
J/kg throughout SE AZ. SSEO members, complimentary WRF high res
windows, and HRRR output all suggest fairly concentrated
thunderstorm activity erupting through Pima and southern Pinal
counties by mid afternoon. Instability may be more muted with
notable Cinh further north into Maricopa County, however substantial
DCape in excess of 1000 J/kg would support more organized outflows.
Typical best performing convective models are not overwhelmingly in
agreement regarding expansive well organized outflows and SSEO
neighborhood probabilities for stronger wind gusts remains low,
though conceptually one would expect some isolated strong outflows
and blowing dust. Kept this mention in the forecast, though the
window in time and space for greater impacts would likely be much
less than is typical during warm season convective events.
Whatever convective activity does manage to survive into the
forecast area should gradually wane this evening with the loss of
daytime heating, and propagate into far eastern AZ as the supporting
shortwave lifts into the four corners. Flow aloft on Sunday will
gradually become more anti-cyclonic and subsident though enough
residual moisture may linger over higher terrain of eastern AZ to
support and isolated shower in parts of Gila County. Otherwise,
clearing and increasing heights aloft will support afternoon highs
near or warmer than experienced on Friday (i.e. mid to upper 90s).
Medium range operational models and NAEFS members remain in very
good agreement advertising a high amplitude blocked northern stream
throughout North America coincident with a more progressive southern
stream flow flanked equatorward by an expansive east-west oriented
subtropical ridge along the far southern tier of the United States.
Locally, Monday and Tuesday will be characterized by dry subsident
flow, H5 heights in a 585-588dm range, and afternoon H8 temperatures
hovering around +20C to +22C. Resultant highs will favor +5F-10F
above average with readings flirting with the 100F threshold across
parts of SE CA. At some point during the middle of the week, a fast
moving shortwave will dampen heights and temperatures aloft
slightly, though enough spread among forecast models exists to
precluding pinpointing which exact day may be notably "cooler". In
reality, this "cooling" only represents shaving 2F-5F from early
week temperatures closer towards the seasonal normal before readings
rebound back into an above average range for the end of the week
under stronger ridging aloft.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
Thickening mid/high clouds will continue overnight with some
scattered showers possibly developing after 12Z. Cigs, even with
showers, will remain AOA 8kft. Showery activity ends after 17-19Z as
gusty easterly winds develop. Additional showers possible later
Saturday afternoon, even a low chance of TS (not included in TAF).
More likely would be outflow winds from distant storms - will be
monitoring for future inclusion in TAFs.
Southeast California/Southwest Arizona including KIPL and KBLH:
Winds will remain light and out of the north at KBLH and out of the
northwest at KIPL. Skies will remain mostly clear today with a
gradual increase in cloud cover through tomorrow morning.
Aviation Discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday:
Dry southwesterly flow aloft will continue to spread across the
region and continue into the end of next week. Minimum humidities
will be in the 15-30 percent range across the region on Monday.
Thereafter, humidities will remain low, near the 10-25 percent range.
Overnight recovery will be good to excellent. Although conditions
will be dry, winds will remain on the light side, with the exception
of a few periods of breeziness up to 20 mph on Thursday in southeast
California and on Friday in southwest and south-central Arizona. High
temperatures over the deserts will stay in the 90s during the period
and generally be above seasonal normals. Warmest western deserts may
be near 100 degrees on Monday.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures today.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO
AVIATION...Hernandez
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Wilmington NC
1028 AM EDT Sat Oct 8 2016
.SYNOPSIS...
The center of Hurricane Matthew will move very near the coast of
South Carolina this morning, and should barely miss Cape Fear this
evening as the storm turns east and moves out to sea. Life threatening
flash flooding, damaging winds, and storm surge flooding are expected.
Behind Matthew, Canadian high pressure will bring the coolest air
of this Fall season, with dry weather expected through Friday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM Saturday...Entire Forecast area is under a flash
flood warning now with very impressive rainfall totals rolling in.
Saturated ground and tropical storm force gusts have combined for
a number of downed tree reports and numerous power outages.
Watches and warnings continue as before. Latest HRRR guidance has
center of Matthew about 50 NM directly south of Cape Fear at 7 PM
this evening. Previous discussion follows:
Hurricane Matthew will continue to move north-northeastward along
the South Carolina coast this morning, turning more east-
northeastward toward Cape Fear this evening. Tremendous moisture
content in the atmosphere (precipitable water values 2.6 to 3.0
inches) is not only a record high for October, but likely is in
the top few events for all of recorded history here! An
exceptionally high risk for flash flooding exists as an additional
7-10 inches of rain is expected to fall today, making storm totals
near 15 inches in spots. Referencing values on the NOAA
Precipitation Frequency Atlas, 45-day rainfall totals (Sep 1
through Oct 15) are probably going to be in the 50 to 100 year
average return interval after Matthew is done with us.
Matthew should soon lose its symmetry as a tropical cyclone as
wind shear increases and begins to tilt the upper portion of the
circulation northeastward (downshear). The southern half of the
circulation also continues to ingest rain-cooled air off Georgia
and South Carolina, and this should continue to concentrate heavy
rainfall more preferentially in the northwestern quadrant of the
storm where the flow is onshore from the high heat content of the Gulf
Stream.
Tropical storm force winds will continue to spread northward
along the coast this morning, but I fear there is a surprise
waiting for us late this afternoon into this evening. For several
days the GFS model has been indicating as the center of Matthew
passes south of Cape Fear, rain-cooled air across interior North
Carolina would get pulled south behind the storm. As lapse rates
steepen in the lowest 1500-2000 feet of the atmosphere, winds of
60-80 mph may get transported down through this mixed layer to the
surface. For many locations north of Myrtle Beach this may be the
strongest winds we see from the entire event, and could pose quite
a shock as the system will seem to be on its way out to sea by
then. After a foot of rain, gusts this strong would almost
certainly uproot trees causing power outages and blocked roads.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM Saturday...With Matthew pulling off to the east and
the coolest airmass of this Fall season building in, we should
have two days of crisp, dry weather with dewpoints plunging into
the 40s. Highs both days should run within a few degrees of 70
with overnight lows in the 40s or lower 50s. There is actually a
lot of spread among various models with lows Monday night/Tuesday
morning. We`re not quite as cold as the 00z GFS, although I`m
trending the forecast in that direction.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 320 PM Friday...The extended still looks very uneventful as
the mid level pattern will show a some amplitude early with a
mostly zonal flow developing late. Early on a modest ridge moves
across the Tennessee Valley and eventually dampens. This will
allow a very cool airmass to advect in behind Matthew. Guidance
has cooled considerably since this time as has the official
forecast. The airmass modifies later in the week with another
front expected to move across late Thursday or early Friday. No
pops in the forecast.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
As of 12Z...Needless to say, not a good aviation day. Look for
increasing winds as the center of Hurricane Matthew drives up the
coast. Winds will gust to near hurricane strength by mid morning
south continuing through the afternoon hours. Ceilings will bounce
around but will be predominately IFR, as well as the visibilities in
heavy rain. Winds will shift rather abruptly this evening as the low
moves east, still gusting over 50 kts.
EXTENDED OUTLOOK...VFR possible MVFR for the inland terminals
during the pre-dawn Sun hours. MVFR possible IFR for the coastal
terminals during the pre-dawn Sun hours. All terminals should
become VFR during or by daylight Sun morning. The Winds will
remain gusty with a slow diminishing trend during the day on
Sunday. VFR Sunday night thru Tuesday.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM Saturday...Impressively high seas this morning as
Matthew churns up the coast. We are seeing around 20 ft out at
41013 and 13 ft at the 41110 near-shore buoy. Winds are gusting at
tropical storm force throughout the waters. Hurricane warnings
continue over the waters as before. Previous discussion follows:
As Hurricane Matthew moves northward along the South Carolina
coast today and then turns northeastward toward Cape Fear this
afternoon, marine weather conditions will remain exceptionally
hazardous. Winds will increase to the 45-60 knot range with higher
gusts south of Cape Fear today. Seas from 10-20 miles from shore
should increase to 12-18 feet.
As Matthew`s center moves toward Cape Fear this evening, cooler
air lurking over interior North Carolina will be pulled southward.
Steep lapse rates within this cooler air should transport down
55-65 knot gusts to the surface, leading to a second period of
very strong winds. This could be the strongest portion of the
storm for the Brunswick County beaches and Cape Fear area.
Offshore wind directions developing overnight should begin to
smooth out the sea state, although very large backswell will
continue to make marine conditions very hazardous.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM Saturday...As Matthew moves eastward and away from
the Carolinas, Canadian high pressure over the Great Lakes will
push the coolest airmass of this Fall season southward. Strong
northerly offshore winds Sunday will only slowly diminish in speed
Monday, likely keeping conditions too rough for small craft,
especially with considerable backswell still moving in from the
east.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
As of 320 PM Friday...Rugged conditions will continue for the
marine community through the period. A broad surface trough will
be aligned offshore with strong high pressure building in from the
northeast. These features coupled will keep a good 20-25 knots
across all waters Monday scaling back slowly Tuesday and
Wednesday. Significant seas will go from 6-10 feet Monday to 3-6
feet Wednesday.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...Hurricane Warning for SCZ053>056.
Flash Flood Watch through late tonight for SCZ017-023-024-032-
033-039-053>056.
Tropical Storm Warning for SCZ017-023-024-032-033-039.
High Rip Current Risk until 8 PM EDT this evening for SCZ054-
056.
NC...Hurricane Warning for NCZ105>110.
Flash Flood Watch through late tonight for NCZ087-096-099-
105>110.
Tropical Storm Warning for NCZ087-096-099.
High Rip Current Risk until 8 PM EDT this evening for NCZ106-
108-110.
MARINE...Hurricane Warning for AMZ250-252-254-256.
&&
$$
SYNOPSIS...TRA
NEAR TERM...REK/TRA
SHORT TERM...TRA
LONG TERM...SHK
AVIATION...DL
MARINE...REK/TRA/SHK
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
610 AM CDT Sat Oct 8 2016
.SHORT TERM...(Today and tonight)
Issued at 309 AM CDT Sat Oct 8 2016
Today and Tonight...sfc low pressure across northeast WY is progged
to move east along the SD-Neb border this morning and drop a back
door cold front into Ncntl Neb this afternoon. This could hold highs
in the 60s across Nrn Neb while Cntl and Swrn Neb rise into the 70s.
The forecast uses the bias corrected RAP and LAV data which was
cooler than the MET MAV EKDMOS and ECS guidance across northern Neb.
It also captures the cooling effect of the snow cover across the
Sandhills which still lingered in some areas Saturday afternoon.
The cloud cover on satellite across MT and the Dakotas is forecast to
move east and remain north of Nebraska. Generally clear skies are
expected today and tonight. Low pressure will deepen across the Nrn
High Plains tonight producing south winds across Wrn and North
Central Neb. A blend of the MET MAV EKDMOS and ECS guidance plus bias
correction suggested lows in the 30s to near 40.
.LONG TERM...(Sunday through Friday)
Issued at 309 AM CDT Sat Oct 8 2016
Zonal flow to prevail across the central Plains which will induce a
the development of a surface trough off the Lee of the Rockies.
Southerly flow will increase as a result and lead to breezy...but
warm conditions. The latest medium range guidance indicates
widespread 70s for highs. There remains a disorganized area of low
pressure that moves from the southern Rockies out onto the southern
Plains...which may spark off an isolated shower or thunderstorm to
our south and southeast. Weak instability is in place across our
southern zones and with forcing for ascent arriving from the south,
it is possible that our far southeastern zones see a thunderstorm
during the afternoon and evening hours.
The next system of interest rapidly advances from the Pac NW across
the northern Rockies and making the northern plains by 00Z
Wednesday. In advance of the shortwave the models suggest
southwesterly downsloping winds...which will help boost high
temperatures into the 80s Monday afternoon for most locations.
The shortwave will force a cold front across the CWA early on
Tuesday. A stark cooldown is forecast for mid-week with highest in
the 50s /north/ and lower 60s /south/. The front arrives when the
troposphere is moisture starved, thus at least initially, rain
chances are slim. The models continue to advertise sufficient
saturation when the large scale forcing associated with the
shortwave trough arrives. Will maintain slight chance to lower end
chance pops Tuesday evening into early Wednesday for much of the
forecast area.
Beyond early Wednesday the forecast is dry as forcing for ascent is
largely absent save for an unorganized shortwave passing in the
southern stream late week. Temperatures will warm once again late
week as thermal advection and rising heights build east from the
Rockies.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 609 AM CDT Sat Oct 8 2016
VFR is expected all areas today and tonight. A weak cold
front...currently draped across the Dakotas...will drift into
Ncntl Neb this afternoon and Wrn Neb tonight. No significant high
or low clouds are expected along the front.
&&
.FIRE WEATHER...
Issued at 300 AM CDT Sat Oct 8 2016
Dry air in the lower and mid levels of the troposphere will combine
with warm temperatures to create near RFW criteria RH across
southwest Nebraska today and for much of the sandhills and southwest
Nebraska on Monday. Wind speeds are forecast to remain well below
criteria, but early Tuesday a cold front is slated to arrive, which
will provide for a distinct wind shift and increase in speeds.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...Jacobs
AVIATION...CDC
FIRE WEATHER...Jacobs
Area Forecast Discussion
National Weather Service Marquette MI
741 AM EDT Sat Oct 8 2016
.SHORT TERM...(Today and tonight)
Issued at 511 AM EDT SAT OCT 8 2016
WV imagery and RAP analysis indicated a mid/upper level low just nw
of James Bay with troughing into the wrn Great Lakes. At the
surface, brisk wrly flow prevailed between the low near James Bay and
a ridge from Saskatchewan through srn MN. Radar and sfc obs
indicated sct lake effect rain showers over ern lake superior and
some lighter pcpn into the nw cwa supported by moderate instability
with 850 mb temps around -3C and lake temps in the 10C-14C range and
a moist 850-700 mb layer. Otherwise, IR loop showed mostly cloudy
skies across the area.
Today, 850 temps remaining around -2C will continue to provide
enough instability for sct -shra for locations favored by wrly flow.
As the low level winds gradually veer to the nw with high pres
building into the nrn Ontario, look for greater pcpn coverage into
the ern cwa this afternoon. Over the rest of the area, Fall-like
conditions with highs from the upper 40s west to the lower 50s east
under mostly cloudy skies are expected.
Tonight, winds will diminish and continue to veer to the north as
the high builds closer to the region. Even though inversion heights
drop slightly, 850 mb temps remaining in the -2C to -4C range will
bring sct -shra into much of n cntrl upper MI. Wet-bulb zero heights
suggest that the pcpn will remain as rain. Mostly cloudy skies
should keep temps from falling off too far, but mins in the lower
30s are still expected over the inland west half with readings in
the upper 30s to lower 40s near the Great Lakes.
.LONG TERM...(Sunday through Friday)
Issued at 253 AM EDT SAT OCT 8 2016
The start of the long term begins 12Z Sun with a SFC high over the
area and 850mb temps around -3C. Should see some isolated to
scattered lake effect rain showers mainly Sun morning, but can`t
rule out precip sticking around into Sun afternoon over the east.
The high moving through will switch winds around to the south from
west to east, ending the precip in that order. Upper ridging will
also moving in later in the day, bringing a warmer airmass along
with it.
The SFC high will continue to shift east while a SFC trough moves
toward the area from the west Sun night and Mon. 850mb temps
increase to around 12C by Mon afternoon. The parent upper trough for
this system will be over the Pacific NW on Mon, with potential for
some weak shortwaves and associated scattered showers to move into
the area late Mon into Tue. Main precip threat comes Tue night into
Wed morning as the upper trough approaches and the SFC trough/cold
front move through. Have high chance to likely PoPs during that time
period.
May need higher PoPs behind the cold front as models indicate 850mb
temps dropping a few degrees below 0C through Thu, but models vary
in the magnitude and duration of the colder air, as well as with
wind directions. Models do agree on a warmup late this week into the
weekend. Overall stuck close to blended guidance.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 741 AM EDT SAT OCT 8 2016
Strongest winds to near 30 kts will be at CMX through this afternoon.
Expect sct/isold lake effect rain showers today in westerly flow at
CMX where mainly mvfr cigs are expected today. As winds veer nrly
tonight and somewhat drier air moves in, expect VFR cigs. The wind
direction will be less favorable for lake effect pcpn at IWD and SAW
where vfr or high end mvfr cigs should prevail.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 511 AM EDT SAT OCT 8 2016
West winds to 30 knots are expected today that will gradually veer
to the northwest. Winds will diminish to under 15kt late tonight
into early Mon as high pres moves across. SW winds will increase to
30 kts later Mon and Mon night ahead of another low pressure system
then shift to the northwest to 20-25 kts behind the system on
Tue/Wed.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...JLB
MARINE...JLB
Area Forecast Discussion...Updated
National Weather Service Phoenix AZ
555 AM MST SAT OCT 8 2016
.UPDATE...Updated aviation discussion.
&&
.SYNOPSIS...
Scattered light showers will return to parts of Arizona today with
more thunderstorms and brief local heavy downpours and gusty winds
late this afternoon and evening. Dry conditions will return next
week with temperatures hovering well above average throughout much
of the week.
&&
.DISCUSSION...
Both WV imagery and objective analysis indicates a jet streak
punching into NW Mexico early this morning with attendant downstream
difluence and ascent spreading into southern AZ. However, backed
lower/middle tropospheric winds have been slower in advecting
sufficient moisture towards central AZ with deeper 6-7 g/kg mixing
ratios and theta-e advection still languishing in SE AZ. Both 21Z
and 03Z SREF probabilities have retreated from more bullish numbers
advertised yesterday; and most high resolution model output only
briefly develops showers within the forecast area bounds before
lifting activity north (and most concentrated through Gila County
and northern edges of Maricopa Co). Still, with the good ascent
structure entering the region and moisture not far away, feel some
measure of showers are still possible through central AZ this
morning, though pared back POPs somewhat to account for less overall
coverage.
While the reflection towards morning showers has waned somewhat in
model output, the propensity towards more extensive deeper
convection this afternoon has grown in high resolution models. There
is fair evidence that thicker high clouds will at least partially
clear today allowing better sfc insolation and MLCape around 1000
J/kg throughout SE AZ. SSEO members, complimentary WRF high res
windows, and HRRR output all suggest fairly concentrated
thunderstorm activity erupting through Pima and southern Pinal
counties by mid afternoon. Instability may be more muted with
notable Cinh further north into Maricopa County, however substantial
DCape in excess of 1000 J/kg would support more organized outflows.
Typical best performing convective models are not overwhelmingly in
agreement regarding expansive well organized outflows and SSEO
neighborhood probabilities for stronger wind gusts remains low,
though conceptually one would expect some isolated strong outflows
and blowing dust. Kept this mention in the forecast, though the
window in time and space for greater impacts would likely be much
less than is typical during warm season convective events.
Whatever convective activity does manage to survive into the
forecast area should gradually wane this evening with the loss of
daytime heating, and propagate into far eastern AZ as the supporting
shortwave lifts into the four corners. Flow aloft on Sunday will
gradually become more anti-cyclonic and subsident though enough
residual moisture may linger over higher terrain of eastern AZ to
support and isolated shower in parts of Gila County. Otherwise,
clearing and increasing heights aloft will support afternoon highs
near or warmer than experienced on Friday (i.e. mid to upper 90s).
Medium range operational models and NAEFS members remain in very
good agreement advertising a high amplitude blocked northern stream
throughout North America coincident with a more progressive southern
stream flow flanked equatorward by an expansive east-west oriented
subtropical ridge along the far southern tier of the United States.
Locally, Monday and Tuesday will be characterized by dry subsident
flow, H5 heights in a 585-588dm range, and afternoon H8 temperatures
hovering around +20C to +22C. Resultant highs will favor +5F-10F
above average with readings flirting with the 100F threshold across
parts of SE CA. At some point during the middle of the week, a fast
moving shortwave will dampen heights and temperatures aloft
slightly, though enough spread among forecast models exists to
precluding pinpointing which exact day may be notably "cooler". In
reality, this "cooling" only represents shaving 2F-5F from early
week temperatures closer towards the seasonal normal before readings
rebound back into an above average range for the end of the week
under stronger ridging aloft.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL: Expect
thickening and lowering clouds this morning as an upper low moves
slowly east across the area...with cigs to lower to around 10k feet
by 14z or so. As supported by a variety of local models, isolated
showers have begun to percolate over the greater Phoenix area and
thus have updated TAFs to include VCSH. Showers should persist on
and off into the afternoon, then decrease into the evening.
Thunder remains a possibility with better chances in the afternoon
but we have already seen an isolated storm this morning mainly west
of KPHX. Confidence in areal coverage and timing issues still a bit
low and will hold off for now on updating TAFs to mention thunder.
Cannot rule out a storm affecting KPHX or one of the other TAF sites
this morning. Lowest cloud decks mid morning thru afternoon should
be 7-8k feet unless more rain than expected occurs leading to
lowered bases/cigs. Clearing to take place this evening with cloud
decks becoming few-sct for the most part. Winds to favor the east to
southeast next 24 hours with little chance of a westward swing later
this afternoon, and we should see some gusts over 20kt during the
mid morning to early afternoon time frame as well.
Southeast California/Southwest Arizona including KIPL and KBLH: No
threat of precip next 24 hours and most cloud decks to be aoa 15k
feet today. By early evening skies to become clear or mostly clear.
Winds to favor the north-northeast next 24 hours at KBLH and during
the afternoon at KIPL, with speeds mostly below 10kt.
Aviation Discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday:
Dry southwesterly flow aloft will continue to spread across the
region and continue into the end of next week. Minimum humidities
will mostly be in the 15-20 percent range across the deserts each
day with the western deserts and southeast CA lowering to 10-15
percent Tuesday and Wednesday. Overnight recovery will be good to
excellent. Although conditions will be dry, winds will remain on the
light side each day with only typical afternoon local breeziness.
High temperatures over the deserts will stay in the 90s during the
period and generally be above seasonal normals. Warmest western
deserts may be near 100 degrees on Monday.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures today.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...Hernandez/CB
Area Forecast Discussion
National Weather Service Blacksburg VA
945 AM EDT Sat Oct 8 2016
.SYNOPSIS...
A cold front will cross east through the Ohio Valley today and
through the Mid Atlantic region tonight as Hurricane Matthew moves
northeast along the Carolina coast. High pressure will build in
Sunday and remain over the much of the eastern United States
through Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 945 am EDT Saturday...
Around 8 am/12z this morning, Hurricane Matthew was about 20 miles
SSE of Charleston, South Carolina and moving northeast around 12
mph. The NHC track still has the hurricane moving northward today
along the South Carolina coast, then turning right tonight
into Sunday morning. The northwest edge of the large shield of
rain associated with Hurricane Matthew will advanced into the
foothills and Piedmont of Virginia and North Carolina today.
Meanwhile, a cold front to our west continue to move east today
into tonight. Several forecasting challenges today with
sharp edge to moderate to heavy rains and the gradual drying
or ending of the rain with the cold front. For this morning
isc grids update included the mention of heavy rains in the
southeast portions of forecast area. Also, elected to slow down
the timing of the drying in the west. Initially shaped pops
towards WSR-88d trends and then leaned to HRRR for late morning
into this afternoon. Made some minor adjustments in temperatures
with latest sfc obs and blended in the lamp guidance for late
morning into this afternoon. Increased winds and winds gusts
slightly across the higher terrain and across the south. More
changes later this morning.
As of 445 AM EDT Saturday...
The northwest edge of the large shield of precipitation associated
with Hurricane Matthew had advanced into the foothills and
Piedmont of Virginia and North Carolina. A cold front trailed from
Lake Erie to Louisiana this morning. Rain extended from central
New York into northeast Tennessee ahead of this boundary.
Models were in good agreement that precipitation would gradually
end from west to east today and tonight. Expect much of the area
west of the Blue Ridge to be dry by this evening, with the rain
exiting the piedmont by early Sunday morning. From 8AM today
through 8AM Sunday rainfall amounts will be heaviest east of a
Lynchburg to Martinsville line. The tropical air mass and warm
rain process will lead to heavier rainfall in that area.
Similar to Friday, clouds and precipitation will translate to only
a small rise in temperatures today. Have stayed close to the MAV
guidance which was just a few degrees above temperatures at 3AM.
The cold front will cross through the area tonight leading in
cooler and drier air. Surface points drop enough for temperatures
to lower in the 40s in the mountains overnight.
850MB winds increase from the north into the 40 to 50 knot range
tonight. Expecting the gusty winds to become more common at
higher elevations behind the front late tonight. Wind gusts rise
close to advisory criteria at the highest elevations from Grayson
county into northwest North Carolina early Sunday morning.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
As of 330 AM EDT Saturday...
Matthew will be looping away from the region on Sunday as low amplitude
ridging builds over the eastern US and allows a large area of high
pressure to move into the northeast through the first part of next
week. This will yield a dry forecast for the Appalachians and central
mid Atlantic region through the period.
There will be a very tight pressure gradient between departing Matthew
and the large high moving in from the west. This will generate very
windy conditions, especially at the higher elevations from the
mountains of NC into the southern Blue Ridge on Sunday. Guidance is not
universal in mixing advisory criteria winds to the surface so will wait
for later runs to assess potential for any wind advisories.
The high will then wedge down the east side of the Appalachians on
Monday and remain as such through Tuesday. Moisture fields indicate
that it will be a dry wedge, so aside from keeping temperatures on the
cool side there will be little associated sensible weather with the
wedge. Lows will be quite chilly Sunday and Monday night with readings
in the 30s expected form the Ridge westward, low to mid 40s to the east.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
As of 230 PM EDT Friday...
During most of this portion of the forecast, a broad area of high
pressure will extend from the Gulf Coast to New England. Limited
cloud cover, very limited precipitation, and a warming trend to
near/slightly above, normal temperatures expected. Guidance is
hinting that two distinct shortwave troughs may move into and through
the northern extent of the ridge, one on Thursday, and one on Friday.
Each of these could have the potential for bringing some isolated
showers into western parts of the area. Currently, the one slated
for Friday looks have the best chance of bringing some isolated to
scattered showers to parts of the area, and and overall trend
towards increasing cloud cover for the whole region.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
As of 745 AM EDT Saturday...
Radar showed coverage of light to moderate rain west of the Blue
Ridge was gradually diminishing. The western side of the
precipitation shield around Hurricane Matthew was becoming fixed
from Lynchburg to Martinsville. The precipitation over the
mountains will be exiting the region by 18Z. High confidence that
the rain may not end at KDAN until after 00Z.
Widespread MVFR to IFR ceilings will remain in place until the
hurricane moves farther north and the cold front in the Ohio
Valley crosses the Mid-Atlantic region tonight. Decent agreement
in the models that ceilings would begin to lift after 18Z,
generally from west to east with conditions improving to VFR after
00Z/8PM.
Winds will increase in the afternoon and overnight in the
foothills and piedmont of Virginia and North Carolina. Wind gusts
up to 25 knots are possible at KDAN especially after 06Z/2AM.
Extended aviation discussion...
For Sunday through Wednesday, models are keeping the area mainly
dry, although this is subject to change pending the track of
Matthew. Most models have Matthew circling off the southeast coast
through the middle of next week. For the latest storm track
forecast see the latest NHC Advisory for Matthew.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...MBS
LONG TERM...DS/MBS
AVIATION...AMS/JH
Area Forecast Discussion
National Weather Service Seattle WA
900 AM PDT Sat Oct 8 2016
.SYNOPSIS...A frontal system will be over Western Washington through
tonight. The front will probably move south and hang up over the
south part of the Cascades on Sunday. Dry weather will prevail
Monday through Wednesday of next week. A Stormy pattern will return
for the latter part of next week.
&&
.SHORT TERM...A front over the area today could shift south
by about daybreak Sunday. Models have trended faster shifting the
rain to the south. See the hydrology section below for a discussion
of the rain and the flood watch. The front should be south of the
area by midday Sunday for a dry afternoon and Monday will be dry as
a ridge of high pressure takes over for a few days.
.LONG TERM...An upper ridge will be over the area Tuesday for dry
and mostly sunny weather but somewhat chilly early morning
temperatures. Clouds will probably begin to increase Wednesday as a
front approaches. Wet and blustery weather will return Thursday and
Friday as vigorous frontal system move onshore. Schneider
&&
.AVIATION...A warm front will stall over Western Washington today
for rain across the area. The flow aloft is westerly. The air mass
is moist and stable with mainly IFR to MVFR ceilings across Western
WA. The cold front will slowly shift S/SE through the area tonight
with rain continuing. 33
KSEA...Light rain or drizzle this morning with MVFR cigs. May see
slight improvement to the cigs this afternoon. South winds
increasing by 18-20z with gusts to 15 kt. Rain continuing tonight
with winds flipping back to northerly by 12z. 33
&&
.MARINE...A warm front will stall over the region today with south
flow increasing over the waters. Small Craft Advisories are in
effect. The cold front will slowly shift south through Western
Washington tonight...with the flow turning W/NW behind the front.
Northerly flow will continue on Monday with high pressure over
interior B.C. Offshore flow will prevail on Tuesday with the next
weak front arriving on Wednesday. A stronger Pacific storm system
will arrive on Thursday. 33
&&
.HYDROLOGY...A front over the area will bring rain today. Rain
will continue tonight but could end by daybreak Sunday for most of
Western WA. The 12z NAM shows the heaviest rain today in the
Olympics and North Cascades, then tonight in the Olympics and
Central Cascades. After midnight tonight the rain ends for the
Olympics but the Cascades get another dose--this is the 12z NAM
solution only--and then all of Sunday the front is hung up over the
South Cascades and it is dry over the rest of Western WA. I have not
seen the GFS and UW mesoscale solutions yet, but the HRRR was
especially fast in moving the rain south out of the area--it has the
front hung up over the South Cascades before midnight tonight. A
flood watch is currently in effect for the Skokomish river in Mason
county and Stillaguamish River in Snohomish County for a chance of
river flooding and we will see what the other models show as they
come in today.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Flood Watch Mason and Snohomish county.
PZ...Small Craft Advisory until 9 PM PDT this evening for Coastal
Waters From Point Grenville To Cape Shoalwater Out 10 Nm.
Small Craft Advisory until 5 PM PDT this afternoon for Coastal
Waters From Cape Flattery To James Island 10 To 60 Nm-
Coastal Waters From Cape Flattery To James Island Out 10 Nm-
Coastal Waters From James Island To Point Grenville 10 To
60 Nm-Coastal Waters From James Island To Point Grenville
Out 10 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater 10 To 60 Nm-Northern Inland Waters Including The
San Juan Islands-Puget Sound and Hood Canal.
Small Craft Advisory until 11 PM PDT this evening for Admiralty
Inlet-Central U.S. Waters Strait Of Juan De Fuca-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 3 PM PDT this afternoon for West
Entrance U.S. Waters Strait Of Juan De Fuca.
&&
$$
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You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php
Area Forecast Discussion
National Weather Service Tucson AZ
415 AM MST SAT OCT 8 2016
.SYNOPSIS...Expect scattered showers and thunderstorms this
afternoon and evening. Some strong thunderstorms producing gusty
winds and perhaps resulting in blowing dust may occur. A chance of
showers and thunderstorms continues Sunday mainly near the New
Mexico border. Dry conditions with above normal daytime temperatures
will then prevail Monday through next Friday.
&&
.DISCUSSION...Strong high pressure aloft was centered over south
Texas early this morning, and a negative-tilted upper trough was
moving northeastward across Baja California into Sonora Mexico.
An ample supply of mid/upper level moisture prevailed across
southeast AZ. However, a fairly dry near-surface environment was
ongoing, with dewpoints mostly in the 40s at lower elevations as
of 4 AM MST.
08/00Z Univ of AZ WRF-NAM and GFS and several HRRR solutions were
similar with depicting the initiation of showers/tstms to occur
later today, generally around noon or such. Given the ongoing
easterly surface wind regime, appears a low-level convergence axis
near the Tucson metro area extending southeastward into southern
Cochise County, may eventually be the focusing mechanism for
showers/tstms to develop by early this afternoon. Given the dry
surface-700mb layer and expected associated DCAPE values of 1200-1400
J/kg, the potential exists for some stronger thunderstorms to produce
locally strong wind gusts.
Based on the various NWP data sets, opted to increase PoPs generally
about 10 percent or so versus the inherited forecast for this
afternoon. Thus, expect scattered to perhaps numerous showers/tstms
this afternoon, with the best coverage from Tucson eastward to the
New Mexico border. There should be enough moisture for a slight
chance of showers/tstms this afternoon as far west as western Pima
County. As 700-500 mb layer winds veer from sely early this morning
to swly this afternoon, storm motions should favor a northeasterly
component. As mentioned in the second paragraph, locally strong wind
gusts should occur with the stronger tstms. Thus, have maintained
patchy blowing dust late this afternoon and early this evening for
locales from the northwest portion of the Tucson metro area wwd/nwwd
into western Pima County and south-central Pinal County.
One caveat worth mentioning: have noted that the 08/06Z Univ of AZ
WRF-NAM as well as the 08/09Z HRRR were not quite as strong with the
showers/tstms to occur later this afternoon versus several previous
solutions. At any rate, am still inclined to favor the scenario
already described in terms of spatial/temporal framework, and the
potential of strong or possibly severe thunderstorms capable of
producing damaging winds.
Showers/tstms should dissipate fairly rapidly this evening with the
loss of daytime heating, and the various hi-res models suggest that
dry conditions may prevail area-wide late tonight into early Sunday
morning. Have held to the notion of isolated-scattered showers/tstms
Sunday afternoon mainly near the New Mexico border. Thereafter, dry
conditions will prevail late Sunday night into next Friday. An
amplifying ridge aloft thru mid-week should be displaced by a
progressive shortwave trough moving across the area next Thur.
08/00Z GFS/ECWMF then depict the upper ridge to amplify next Friday
as the shortwave trough moves east into the central CONUS.
High temps today will be about 2-7 degs or so cooler versus Fri,
then daytime temps Sun-Fri will remain about 5 degs or so above
normal.
&&
.AVIATION...Valid through 09/12Z.
SCT -TSRA/-SHRA should develop around 19Z-20Z today, and especially
in vicinity of KTUS. TSRA/SHRA will then expand in coverage while
moving northeastward across much of southeast AZ into this evening.
MVFR conditions due to restricted vsbys/cigs, and wind gusts of 35-
45 kts may also prevail. The bulk of -TSRA/-SHRA is expected to end
by 09/06Z. Cloud decks into Sunday morning will generally be 6k-12k
ft AGL. Surface wind outside of thunderstorm gusts thru the period
ely/sely at 5-15 kts with gusts to 20 kts. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Expect scattered showers and thunderstorms this
afternoon and evening. The best chance for wetting rain will occur
from Tucson east to the New Mexico border. A chance of thunderstorms
continues Sunday mainly near the New Mexico border, then dry
conditions Monday through next Friday. 20-foot winds this morning
and Sunday morning will be east and southeast at 10-15 mph with gusts
to 20 mph. Otherwise, 20-foot winds will be terrain driven less than
15 mph.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
DISCUSSION...Francis
AVIATION/FIRE WEATHER...Lader
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Forecast discussion for routine afternoon forecast issuance
.SHORT TERM...Tonight and Sunday
Issued at 223 PM CDT Sat Oct 8 2016
The latest RAP analysis and satellite/radar imagery show cyclonic
flow over the western Great Lakes, between high pressure centered
over central Canada, and low pressure over James Bay. Weak
shortwave in the northwest flow is sending a band of mid-clouds from
North Dakota to western Wisconsin, and should move across central WI
into east-central WI later this afternoon. Additional enhanced cu
is passing over the Lake Superior region, just north of the U.P.
border. As high pressure builds into area late tonight, cloud cover
trends and temps are the main forecast concerns.
Tonight...Weak shortwave energy will be passing across the region
during the evening. Scattered to broken cloud cover resides
upstream, but models do show this moisture thinning out during the
evening hours, as the clouds move across central and east-central
WI. Will increase sky cover through midnight as a result. High
pressure will build into the area overnight, promoting good
radiational cooling conditions with the clearing skies outside of
Vilas county. Low temps should be falling into the upper 20s in the
cold spots over N-C WI, and through the 30s elsewhere. With
coordination from other offices, will issue frost/freeze headlines
for areas north and west of the Fox Valley.
Sunday...High pressure will be centered over the area. After a
frosty start, should see plenty of sunshine, with scattered clouds
over eastern WI developing with the heat of the day. Low level
temps will be moderating a few degrees, which put highs into the mid
and upper 50s.
.LONG TERM...Sunday Night Through Saturday
Issued at 223 PM CDT Sat Oct 8 2016
Temperatures will begin to recover Monday on the back side of a
departing high pressure system with temperatures rising to 5 to
10 degrees above normal for this time of year. A mid level
shortwave and 850 mb theta-e advection will bring the chance for
showers to the area Monday night and Tuesday. Despite the forcing
there will be a low layer of dry air, therefore rain chances will
be fairly small during this period.
A cold front with better dynamics and meaningful moisture will
arrive Tuesday night and Wednesday, bringing a better chance for
showers to the area. Much cooler temperatures are expected behind
the front as temperatures fall to around 5 degrees below normal.
High pressure will bring clearing skies and light winds to the
western Great Lakes, bringing favorable conditions for another
round of frost development across central and north-central
Wisconsin Wednesday night and Thursday morning. Return flow on
the backside of the high will bring a return to near normal
temperatures on Friday, with temperatures a few degrees above
normal on Saturday.
&&
.AVIATION...for 18Z TAF Issuance
Issued at 1209 PM CDT Sat Oct 8 2016
Though high pressure will be moving across the region during the TAF
period, a weak upper level disturbance combined with some cumulus
will lead to broken conditions at times this afternoon and evening.
Cigs should remain vfr at most locations. Clearing is anticipated
late tonight. Good flying weather will continue into Sunday, with
only diurnal cu popping up over eastern WI.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 3 AM to 8 AM CDT Sunday FOR WIZ005-010>013-
018>021-030-031-035>037-045-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kurimski
AVIATION.......MPC
Area Forecast Discussion
National Weather Service Wilmington NC
655 PM EDT Sat Oct 8 2016
.SYNOPSIS...
The center of Hurricane Matthew in the vicinity of Cape Fear this
evening, will track east northeast, reaching the vicinity of Cape
Lookout around midnight. Weakening Matthew will finally track
offshore, away from the NC Mainland, Sunday thru early next week.
Continued life threatening flash flooding and damaging winds and
storm surge flooding north of Cape Fear are expected this evening.
In the wake of Matthew, Strong, cool and dry Canadian high
pressure will infiltrate the region for much of the upcoming work
week, bringing the coolest air of this early Fall season.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 3 PM Saturday...The entire forecast area remains under a
flash flood warning with very impressive rainfall totals and
numerous reports of flooding rolling in. Saturated ground and
tropical storm force gusts have combined for a number of downed
tree reports and numerous power outages. Watches and warnings
continue as before. The latest NHC warning has Matthew as a
category 1 storm, moving ENE from its present location near Myrtle
Beach, SC to just south of Cape Fear this evening while weakening
to a Tropical Storm. The latest HRRR guidance has center of
Matthew about 30 NM directly south of Cape Fear at 6 PM this
evening.
Matthew has begun to lose its symmetry with an increase in wind
shear, with water vapor imagery showing dry air beginning to wrap
around the south side of the system. In addition, Matthew seems to
be merging with the southern extent of an old frontal boundry. The
southern half of the circulation will also continue to ingest
rain-cooled air off of South Carolina, and this will continue to
concentrate heavy rainfall more preferentially in the northwestern
quadrant of the storm where the flow is onshore from the high heat
content of the Gulf Stream.
As the center of Matthew passes south of Cape Fear, rain-cooled
air across interior North Carolina would get pulled south behind
the storm. As lapse rates steepen in the lowest 1500-2000 feet of
the atmosphere, winds of 60-70 mph may get transported down
through this mixed layer to the surface. For many locations north
of Myrtle Beach this may be the strongest winds we see from the
entire event, and could pose quite a shock as the system will seem
to be on its way out to sea by then. After a foot or more of
rain, gusts this strong would almost certainly uproot trees
causing further power outages and blocked roads.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
As of 3 PM Saturday...With Matthew pulling off to the east and
the coolest airmass of this Fall season building in, we should
have two days of crisp, breezy and dry weather with dewpoints
plunging into the 40s. Temperatures will gradually decrease
through the period as cooler air filters across the eastern
Carolinas and expect highs on Monday to only reach the upper 60s,
with low possibly dropping into the upper 40s well inland. The
period may actually start out with a few showers dropping south
across the area as Matthew moves off to the east, but expect dry
weather to otherwise dominate the period.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 3 PM Saturday...Benign, dry and seasonal weather will
persist through the Long Term as a cool NE flow persists with high
pressure dominating eastern CONUS. A re-enforcing cold front
arriving early on Friday will come through dry and may allow for a
further cool-down to keep us at seasonal temperature levels.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
As of 00Z...Hurricane Matthew is SE of KILM at TAF time. High
confidence MVFR flight restrictions will improve to VFR and rain end
from W-E this evening, with KILM the last to improve around midnight
Z. Winds speeds will be strongest at the coastal terminals early
this evening. In general wind speeds will decrease as from W-E as
Matthew pulls away, but still remain 25-35 kt and gusty overnight.
VFR Sunday with NW-N winds 20-25 kt and gusty through the day.
EXTENDED OUTLOOK...VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 3 PM Saturday...Hurricane Warnings continue for all waters
through the Near Term as Hurricane Matthew continues to move up
the coast of the Carolinas and directly over our coastal waters.
The latest NHC advisory has Matthew as a category 1 Hurricane.
Matthew is forecast to make a turn to the ENE after approaching
the Cape Fear this evening. The strongest winds of this event may
actually happen this evening as north winds get pulled around the
backside of Matthew. Latest obs show seas of 14 ft at the 41110
near-shore buoy, with 21 ft out at 41013.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 3 PM Saturday...Very dangerous boating conditions will
continue through the short term as Matthew pulls off to the east
of the waters. Although the official NHC forecast has Matthew as a
tropical storm by 8 AM Sunday and becoming post-tropical shortly
thereafter, the tight gradient between Matthew and a strong high
pressure to the west will keep winds and seas elevated. Expect the
period to start off with tropical storm-force winds in place, with
conditions remaining unfavorable for marine interests through
Monday night.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
As of 3 PM Saturday...Expect gradual improvement through the
period with high pressure extending south from New England and the
remnants of Matthew pushing further away from the waters as it
gets absorbed by a frontal system. The period may start off rocky
for boating interests and it is possible that an advisory may be
in place at the beginning of the period. Seas will decrease to 3
to 5 ft later on Tuesday or on Wednesday.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...Hurricane Warning for SCZ053>056.
Flash Flood Watch until 6 AM EDT Sunday for SCZ017-023-024-032-
033-039-053>056.
Tropical Storm Warning for SCZ017-023-024-032-033-039.
High Rip Current Risk until 6 AM EDT Sunday for SCZ054-056.
NC...Hurricane Warning for NCZ105>110.
Flash Flood Watch until 6 AM EDT Sunday for NCZ087-096-099-
105>110.
Tropical Storm Warning for NCZ087-096-099.
High Rip Current Risk until 6 AM EDT Sunday for NCZ106-108-110.
MARINE...Hurricane Warning for AMZ250-252-254-256.
&&
$$
SYNOPSIS...DCH
NEAR TERM...REK
SHORT TERM...REK
LONG TERM...REK
AVIATION...MRR
Area Forecast Discussion
National Weather Service Miami FL
451 PM EDT Sat Oct 8 2016
.SYNOPSIS...
Drier air will continue to filter into Florida this evening, as
Matthew pushes further up the North Carolina coastline. There will
be a slight chance of showers over the southern tip of Florida
through this evening, otherwise expect only a few passing high
clouds. Conditions should stay dry into Monday with high
temperatures decreasing slightly each day. A more moist
northeasterly flow may return by mid next week, brining another
chance for shower and storm activity.
.DISCUSSION...
Water vapor imagery this afternoon showed what is now a low end
category 1 Hurricane Matthew traversing northeast up the North
Carolina Coast. A frontal boundary, behind this tropical feature,
could be seen filtering in dry air over northern and central
Florida. A rather stable atmosphere was observed on the 12Z MFL
morning sounding in the lower and mid levels. Latest runs of the
short term models, such as the HRRR and WRF indicate that a
couple of light showers may develop over the Southern tip of
Florida through this evening, so maintained slight chances in the
forecast package. Maximum temperatures across the region should
top out in the lower 90s, a few degrees above the norm for this
time of year. The 12Z GFS continues the southward push of the
aforementioned front towards south Florida tonight. Mostly dry
conditions are forecast for Sunday with PW values lowing to below
1.50". By Monday, cooler weather will be advected into the region
along with lower dewpoints in the mid 60s, a short relief from the
typical muggy conditions.
Tuesday through Friday...NHC has squashed the possibly of Matthew
revisiting South Florida. According to the latest forecast track,
the storm becomes post tropical and diminishes out at sea. Long
range models build high pressure over the northeast Gulf by mid
week. This feature would act to develop northeast flow over South
Florida and bring a return to the lower and mid level moisture.
There will be a chance of showers and storms each afternoon over
the entire region, then limit the activity back to the east coast
at night.
&&
.MARINE...
Winds turn more northerly behind the front on Sunday into Monday,
with seas building once again, particularly in the Gulfstream.
Waves will slowly start to lower by Tuesday afternoon with a
continuing gusty northeast wind.
&&
.PREV DISCUSSION... /issued 147 PM EDT Sat Oct 8 2016/
AVIATION...
Not much change in the forecast. A weak front is moving through
South Florida. This will help to clear out the cloud cover, and
turn the wind to the northwest tonight, and northeast in the
morning. VFR conditions will prevail. TAFs show VRB for the wind
tonight, as it becomes 5 kts or less, and may not have a steady
direction, as it shifts. However, in the morning, it is forecast
to pick up to 10 to 12 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 74 88 73 83 / 0 0 10 20
Fort Lauderdale 75 88 75 84 / 0 10 10 20
Miami 76 89 75 85 / 0 10 20 20
Naples 74 91 68 85 / 0 0 10 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Beach Hazards Statement until 10 PM EDT this evening for FLZ069.
AM...None.
GM...None.
&&
$$
DISCUSSION...27/JT
MARINE...27/JT
AVIATION...SI
Area Forecast Discussion
National Weather Service Mount Holly NJ
406 PM EDT Sat Oct 8 2016
.SYNOPSIS...
A cold front will slide through the region tonight. At the same time
Tropical Cyclone Matthew will start to curve out to the ocean. High
pressure will build towards the region through Tuesday before
shifting northeast Wednesday. On Thursday, a weak cold front could
approach the region. High pressure will then build over the region
to start the weekend.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A cold frontal boundary will move eastward into the region tonight
with moisture from tropical storm Matthew streaming northward ahead
of the front. Drier air will be advecting southward into the region
behind the front as well. The main challenge tonight will be the
main northward extent of the rain shield from tropical storm
Matthew. Modeling still differs quite a bit this afternoon with the
ECMWF and RGEM the furthest north and west with the HRRR and RAP
furthest southeast. Will continue to lean more in the direction of
the modeling that is farther north and west given radar trends this
afternoon.
With this mind forecast expectations are still for rainfall totals
from one to four inches in the southern Delmarva with totals of an
inch or two along the SE Jersey coast. With the drier air advecting
into the region a sharp cutoff will be present with the rain witch
areas north and west of Philadelphia seeing little in rainfall
outside of a few scattered showers this evening. The exact location
of this divide is still uncertain and may be adjusted as the evening
unfolds.
Winds will also begin to increase from the north toward sunrise
behind the front with cloudy skies. Temperatures will be slow to
fall off tonight with lows in the 50`s.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
The cold front will allow for an eastward propagation of the rain
shied and slow clearing from west to east during the morning across
the region. Northerly winds will still be increasing as well. GFS
bufkit analysis shows the potential for some wind gusts around 40
mph, close to wind advisory criteria. However, the NAM and ECMWF
indicate slightly weaker winds. Still some wind gusts Sunday
afternoon may reach 30 mph. With the cool air advection,
temperatures should be rather steady on Sunday, particularly in areas
that see clouds and rain in the morning. Most locations may not see
temperatures much higher than around 60.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Sunday night...biggest concern through this period remains the
potential for patchy frost in the Poconos and NW NJ. However, is is
less certain now how quickly winds will drop off Sunday night. Some
models have winds staying near or above 10 mph across this area. If
this happens, frost is unlikely to develop even with a clear sky and
temperatures dropping to the mid 30s. However, suspect that winds
will decouple, if even for only a few hours, so have kept mention of
patchy frost in the forecast.
Monday...Most guidance trended lower with high temperatures during
this day...with many showing highs 5 to 10 degrees below normal.
Given the strong cold air advection, this seems reasonable.
Monday night...With similar conditions to Sunday night, except
lighter winds, the threat for patchy frost increases and is possible
over portions of the Poconos, NW NJ, and the Lehigh Valley. Will
also have to watch how efficient radiational cooling will be in the
Pine Barrens: for now I have kept temps in this area in the upper
30s which is slightly lower than guidance, but would not be
surprised if temps drop even lower than that.
Tuesday through Wednesday...surface high builds close to the region,
then slides northeast through the day on Wednesday. Weak
southwesterly low level flow should allow for a modest warming trend
through this period.
Thursday...the exact timing is still uncertain, but it looks like a
cold front should slide through the region through this time. Many
models don`t show any precip with this front, but given how close
the upper level trough will be to our region, think it is possible,
so will mention a slight chance of precip through the day on
Thursday.
Friday and Saturday...For the second time of the week, a surface
high is expected build in over the region in the wake of a cold
front, leading to tranquil but slightly cooler than normal
conditions.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Periods of rain will likely lower ceilings and visibilities
throughout much of the night into the MVFR and even IFR category at
times. Winds will be light tonight but increase from the north
around sunrise to around 10 knots.
On Sunday, improvement to VFR is likely during the morning from west
to east, perhaps early afternoon for KACY and KMIV. Northerly winds
increasing to between 15-20 knots with gusts around 25 knots. Some
potential is present for even higher gusts from 30-35 knots but
confidence is lower for gusts this strong.
Outlook...
Sunday night through Wednesday...VFR conditions expected.
Thursday...Mostly VFR conditions expected. Small chance of MVFR
conditions with showers.
&&
.MARINE...
Waveheights will increase this evening and be well above five feet
during the day Sunday. Northerly winds will also increase behind a
cold front. Indications are for a likelihood of some gale gusts on
both the ocean waters and Delaware bay on Sunday. Gale warning now
in effect.
Outlook...
Sunday night...winds will start to subside on the Delaware Bay, but
should remain above 25 kt through the overnight hours. On the
Coastal Waters, expect gale conditions to continue through much of
the overnight before beginning to subside near sunrise.
Monday...winds will slowly subside through the day below SCA
criteria by the end of the day. However, seas are expected to stay
above 5 feet through the day on the Coastal waters.
Monday night through Wednesday...Seas should slowly subside through
this period. Exactly when they will drop below 5 feet on the coastal
waters is still uncertain. Some guidance has elevated seas lingering
through the day on Wednesday. On the Delaware Bay, winds and seas
should stay below SCA criteria.
Thursday...winds and seas should stay below SCA criteria.
&&
.HYDROLOGY...
Periods of moderate to heavy rain are expected tonight across the
southern Maryland and southern Delaware and continue into Sunday.
FFG is fairly low, only around two inches in Sussex DE in six hours
due to heavy rain that fell from 9/27-9/30 that totaled up to 14
inches. Modeled rainfall on average is expected to range from 1-4
inches in the flash flood watch area.
Our QPF forecast continues to hedge the forecast in the direction of
the model guidance that is further north and west with the higher
QPF. Lighter rainfall of an inch or two is possibile over southeast
New Jersey and the mention of poor drainage flooding is in the HWO
for this location.
It should be noted that an even heavier core of rainfall with more
than 4 inches total is expected to track just southeast of the
region. Any additional northwest bump could result in higher QPF.
The opposite would be true as well if the system trends further
south and east which would shift the rain/little rain cutoff closer
to the coast.
&&
.TIDES/COASTAL FLOODING...
ETSS guidance shows both Lewes and Atlantic City getting close to
minor tidal flooding with the Monday evening high tide. For now, I
have not mentioned this in the HWO as it seems unlikely given an
unfavorable wind direction and being in between the new and full
moon.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...Flash Flood Watch through Sunday morning for DEZ002>004.
MD...Flash Flood Watch through Sunday morning for MDZ015-019-020.
MARINE...Gale Warning from 6 AM Sunday to 6 AM EDT Monday for
ANZ450>455.
Gale Warning from 6 AM to 6 PM EDT Sunday for ANZ430-431.
&&
$$
Synopsis...Johnson
Near Term...Gaines
Short Term...Gaines
Long Term...Johnson
Aviation...Gaines/Johnson
Marine...Gaines/Johnson
Hydrology...
Tides/Coastal Flooding...
Area Forecast Discussion
National Weather Service Pueblo CO
331 PM MDT Sat Oct 8 2016
.SHORT TERM...(This evening through Sunday)
Issued at 330 PM MDT Sat Oct 8 2016
...Upper Disturbance to move Across Forecast Area Sunday...
An upper level disturbance, visible on satellite over Arizona and
New Mexico today, will drift across the region through Sunday. This
disturbance will bring a chance of showers and thunderstorms to
most of the area on Sunday and particularly to areas along and south
of Highway 50. Some of the latest HRRR runs are bringing the
moisture farther north and more organized than previously. This
could bring better chances for precipitation to southern Colorado on
Sunday than once thought. However, the convection hasn`t looked
overly impressive to the south of us today so not entirely certain
of the storm`s overall potential. Latest HRRR runs have the best
potential over the southeast plains Sunday. We will see. Primary
threats will be lightning and wind gusts to around 40 mph.
.LONG TERM...(Sunday night through Saturday)
Issued at 330 PM MDT Sat Oct 8 2016
Main longer term meteorological issues continue to be
generally low-grade to nil pops...locally gusty gradient winds
at times and temperatures.
Latest longer term forecast model soundings...computer
simulations and PV analysis continue to indicate that basically
zonal to southwesterly upper flow will continue over the forecast
district into next Saturday with a couple of more upper
systems(per PV analysis...etc.) to contend with during the longer
term.
At the surface it still appears that differing degrees of eastern
Colorado lee-side troughing will be noted from Sunday evening
into Tuesday morning with next northerly to easterly surface
surges impacting primarily eastern sections of the forecast
district from later Tuesday morning into Wednesday night.
Then...similar to previous thinking...next round of eastern
Colorado lee-side surface troughing develops again from later
Thursday into next Saturday.
At this time...the highest potential of precipiation(including
the potential for some higher elevation light snow at times) is
anticipated Sunday evening and then again from Tuesday into
possibly Thursday...with the highest potential of gusty gradient
winds at times expected from Tuesday into Thursday.
Finally, above seasonal mid-October minimum and maximum
temperatures are expected to continue over the forecast district
from Sunday evening into Wednesday morning with near to below
seasonal temperatures then anticipated from Wednesday into
Thursday in advance of warming conditions again by next Friday and
Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 330 PM MDT Sat Oct 8 2016
Upper high pressure will push north of the flight area tonight. As
upper high drifts slowly north, moisture will increase from the
south, resulting in a few evening thunderstorms, mainly over the
mountains south of Highway 50. Increased thunderstorm activity,
reaching farther north, is expected for tomorrow. Primary storm
threats will be lightning and gusty winds. Generally VFR across
flight area next 24 hours, although areas of MVFR, IFR and LIFR
flight conditions may be encountered in areas of convective
precipitation. Storm chances are too low to put in the KCOS, KPUB
and KALS TAF sites over the next 24 hours.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$