Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/25/16
Area Forecast Discussion
National Weather Service Bismarck ND
903 PM CDT Sat Sep 24 2016
.UPDATE...
Issued at 856 PM CDT Sat Sep 24 2016
The surface low over central ND has remained nearly stationary
over the past few hours, while the upper low in the southwest is
starting to track northeast. This is producing a narrow band of
weak instability combines with strong shear across portions of
northwest and far north central ND. due to the surface low not
moving, will have to extend the mention of thunder back to the
west, into northwest ND this evening, and will keep a chance in
the far north central late this evening. Otherwise no significant
changes. Wind advisory is now in effect over the southwest.
UPDATE Issued at 637 PM CDT Sat Sep 24 2016
Surface and upper level low pressure will lift northeast across
the forecast area tonight into Sunday morning. Currently the
surface low is situated over west central ND with the upper low in
far southwest ND. Cold front has made it through northwest ND and
should move across the southwest this evening as the surface and
upper low finally begin to lift northeast.
For the early evening update we adjusted pops/weather based on the
latest radar and satellite analysis. Basically a slower trend
through the night. Day shift had delayed the start of the wind
advisory in the southwest until 7 pm MDT and this looks reasonable
as winds are beginning to move into the northern portion of the
advisory. Will send out updated hazard and text products shortly.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 253 PM CDT Sat Sep 24 2016
Deep cut off upper level low was centered around southeastern
Montana at 18Z with the associated surface low over southwestern ND.
Dry slot of system was supporting mostly dry conditions across
south central ND Saturday afternoon with low level southerly flow
in the warm sector helping increase instability. Dew points in
this area were mainly in the mid/upper 60s and SB CAPE around 1500
J/Kg. High res models show convection developing after 20Z, with
the HRRR showing the stronger cells just outside our area. Any
severe threat should be relatively short lived and over by 00Z
Sun. Also expect showers and stratiform precip to spread from west
to east overnight as upper low progresses across the state,
reaching southern Manitoba as an open trough by 18Z Sun.
Expect strong winds to develop behind the system as the surface
low reaches northcentral ND this evening. Wind advisory that is
in effect tonight for the extreme southwest will be expanded to
the north and east. Will also make some adjustments to the
starting time as winds will be a little slower to strengthen than
originally thought. GFS depicts strongest BL winds around 40 kts
over this area. 0.5 km AGL winds also max at around 50 knots near
Adams/Sioux counties at 09Z.
On Sunday, precip will end from west to east and should be
completely out of the area by late afternoon. Breezy to windy
northwest winds will continue through the day as the low pushes away.
.LONG TERM...(Sunday night through Saturday)
Issued at 253 PM CDT Sat Sep 24 2016
A longwave upper level ridge will build over the Plains during the
week leading to mostly dry weather along with a warming trend. High
temps initially in the 60s on Monday will warm to the low 70s on
Tuesday, with similar highs through Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 856 PM CDT Sat Sep 24 2016
A low pressure system over western ND will lift northeast across
central ND tonight and into eastern ND Sunday morning. At the
beginning of the 00Z TAF period, VFR conditions with a southerly
flow at KJMS KBIS and KMOT ahead of the low. Strong northwest flow
at KISN with mvfr ceiling and rain showers, and poised to push
into KDIK within the next 1-2 hours. MVFR-IFR and possible LIFR
ceilings will spread west to east across central ND TAF sites
tonight, with winds shifting northwest and increasing. Conditions
will improve quickly Sunday morning at each site from west to
east. VFR conditions at all sites by Sunday afternoon, but still
strong northwest winds through 00Z Monday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from midnight CDT /11 PM MDT/ tonight to 6 PM CDT
/5 PM MDT/ Sunday for NDZ019-020-034-042-045-046.
Wind Advisory until 6 PM CDT /5 PM MDT/ Sunday for NDZ017-018-
031>033-040-041-043-044.
&&
$$
UPDATE...TWH
SHORT TERM...JNS
LONG TERM...JNS
AVIATION...TWH
Area Forecast Discussion
National Weather Service Grand Forks ND
934 PM CDT Sat Sep 24 2016
.UPDATE...
Issued at 934 PM CDT Sat Sep 24 2016
Showers and storms have been lifting northeastward a bit faster
than expected, so adjusted POPs accordingly. Continued to keep
some isolated to scattered mention over the western counties as
some cells continue to pop up west of the Red River. Storms
continue to be fairly weak and with the exception of near Lake of
the Woods the lightning strikes have been getting fewer and
farther between. Will adjust weather grids to include just an
isolated thunder mention. The precip will continue to move
eastward throughout the night with wrap around starting in the
Devils Lake area by early morning.
UPDATE Issued at 659 PM CDT Sat Sep 24 2016
Showers and storms have moved into the southern CWA, with a
weakening trend as the convection moves into more stable air. The
more unstable western counties have seen little more than a few
non-severe cells pop up. Adjusted POPs for categorical in the
southeast for the next few hours. The short range models have been
trending a little bit more sparse further north, but kept at least
a short period of likely POPs up to the Highway 2 corridor. High
POPs will continue for the eastern counties through the rest of
the night, with the wrap around showers starting to move into the
Devils Lake basin.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 255 PM CDT Sat Sep 24 2016
The main challenge will be pcpn chances tonight and then the
lingering effects of this system into Sunday. As of mid afternoon
the main tstm action has been over southeast SD into southwest MN.
This activity seems to be more focused along the sfc warm front,
which is tied to the sfc low over southwest ND. The main 500 mb
low is also over the western high plains, quite a bit further west
than our FA. Cloud cover has inhibited temps today, but mainly
over northwest MN. Despite the clouds the strong SSE wind push has
brought up mid 60 dew points and temps in the upper 70s to near
80F across the south.
Instability has risen to about what was expected today, in the
500-1500 J/kg range. However, there still has not been much
activity developing other than that further south. Latest SPC HRRR
shows the activity further south lifting up into mainly west
central MN tonight, but it does have a little pcpn poking up thru
the central and northern Red River Valley. The dry slot will try
to push up into the FA later tonight followed by the wrap around
on Sunday. Gusty northwest winds will also kick up on Sunday, but
at this point it looks like the worst of it may brush the Devils
Lake region and areas just west of the valley. Later shifts can
take another look at that.
.LONG TERM...(Sunday night through Saturday)
Issued at 255 PM CDT Sat Sep 24 2016
Upper level low will begin to exit the area Sunday night with
wraparound showers exiting northwestern Minnesota. Clearing to move
in Monday...though may take a bit longer to clear out the far
eastern fcst area than models indicate. Breezy north-northwest
Sunday night into Monday before diminishing Monday evening as high
pressure ridge begins to move in. Clear or clearing out Monday
night all areas with sfc high over eastern North Dakota by 12z
Tuesday. Looks like a cool night and coordinated with BIS/ABR and
dropped lows below model blend guidance and have mostly upper 30s.
Dry Wed-Thu as upper level ridge builds in for dry and a bit milder
airmass. A weak short wave will move in for Friday into Saturday
giving a chance for precipitation. Temperatures will run a tad
above normal late week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 659 PM CDT Sat Sep 24 2016
Showers and storms have entered the southern forecast area, and
should be in the KFAR area shortly. The showers and storms will
move north and eastward for the rest of the evening, although
coverage further north is somewhat uncertain. Will keep VCTS to
VCSH mention going at all sites but KDVL overnight. KDVL and KBJI
are the only sites not VFR currently, but there should be some
MVFR to IFR ceilings moving in overnight along and behind the
shower and storms. There should be some recovery late tonight and
tomorrow morning as the dry portion of the low pressure system,
but MVFR ceilings will return by the end of the period behind a
cold front. There will also be some scattered showers wrapping
around so have VCSH at the end of the period for all but KFAR.
Winds from the southeast will start to diminish and shift to the
southwest overnight. A cold front coming in tomorrow morning will
shift winds to the northwest and there could be gusts over 30 kts
in the afternoon.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...JR
SHORT TERM...Godon
LONG TERM...Riddle
AVIATION...JR
Area Forecast Discussion
National Weather Service Grand Junction CO
841 PM MDT SAT SEP 24 2016
.UPDATE...
Issued at 841 PM MDT Sat Sep 24 2016
Precipitation across northwest Colorado into the I-70 corridor has
been a little slower than expected in winding down. IR satellite
images still show moisture upstream across southern WY. Therefore
have upped pops/clouds somewhat for the next few hours. Do not
expect much in the way of additional snow accumulations along the
Park, Elkhead and Flat Tops mountains as snow seems to be on the
light side based on the few observations and web camera shots
available. Conditions are still expected to improve by late
tonight with precipitation ending before dawn. Otherwise no other
changes to the grids.
&&
.SHORT TERM...(Tonight through Monday)
Issued at 252 PM MDT Sat Sep 24 2016
A few rain and snow showers hanging on late this afternoon in
wrap-around flow as the main upper low continues to lift northeast
into the North Dakota. HRRR and RAP keep the light showers rolling
through late this evening, before shutting things down as mid
level flow becoming more north to northeasterly introducing more
of a downsloping component for much of our forecast area. Cloud
cover will be the big factor with potential freezing temperatures
overnight with our higher valleys the biggest concern. Steamboat,
Craig and Gunnison have all had hard freezes earlier this month
and other guidance in remaining high valleys holds temps up a bit
with clouds and higher surface moisture in place. Will hold off
on an highlights for freezing temps at this time with expectation
that any run to or slightly below freezing will be very late and
short-lived. Secondary concern will be areas of fog in the
valleys late tonight and have this covered in the latest forecast
package.
Sunday and Monday will be dry with high pressure building
overhead. This will result in light winds, seasonal daytime highs
and cool overnight lows.
.LONG TERM...(Monday night through Saturday)
Issued at 252 PM MDT Sat Sep 24 2016
Upper level ridging will be migrating east Monday night and
Tuesday with southwest flow returning by midweek. Pattern looks to
remain dry through Tuesday before moisture starts lifting back
north into the southern zones on Wednesday as the remnants of
another tropical system get caught up in the flow. ECMWF and GFS
in decent agreement with kicking a wave out across the forecast
area Thursday with additional energy to follow through the
weekend. So after a slow start to this extended period, things
will become more interesting as we close out the week with rain
and mountain snow returning to the forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 504 PM MDT Sat Sep 24 2016
Showers will continue through early evening across northwest
Colorado and west-central Colorado as a deep trough from a storm
system to the north tracks over the area. Reduced cigs/vsby is
expected among heavier showers with frequent mountain obscurations
through about 03z in rain and snow. TAF sites are expected to
remain light rain with low ceilings until about 03z...then clearing
skies are seen behind the exiting trough. VFR conditions will
return late this evening through Sunday as a drier airmass takes
hold.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
UPDATE...EH
SHORT TERM...JDC
LONG TERM...JDC
AVIATION...CC
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1008 PM EDT Sat Sep 24 2016
.SYNOPSIS...
A cold front will drop south across the area tonight followed by
high pressure from the north Sunday through Monday. Another cold
front will move through from the west Tuesday night, then high
pressure will build in from the northwest Wednesday through
Friday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1005 PM Saturday, cold front continues to makes its slow
trek into northern NC and should move slowly across the region
overnight into early Sunday. Adjusted the timing of precipitation
to closer to morning as latest 15-minute 3-km HRRR model shows any
light precipitation over the far northern counties early Sunday
morning, but the chances will be quite slim. No changes to
temperature forecast overnight with lows upper 60s to lower 70s.
Expect to see more stratus versus fog with the frontal passage
given decent mixing.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
As of 3 PM Sat...High pressure will extend over the area from the
north Sunday night, shifting off the east coast Monday night.
Coolest night will be Sunday night with low level E/NE flow.
Overnight lows in the 60s. Low level flow will gradually veer
through the day Monday as high shifts eastward and front
approaches from the west. Low level thickness values support highs
in the upper 70s to lower 80s...and will feel much more pleasant
with dewpoints in the 60s. Overnight lows Monday night in the mid
60s to low 70s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
As of 3 PM Sat... Moisture will begin to overspread the area from
the south into Tuesday as winds veer to SSW ahead of a cold front
approaching from the west. Reintroduced slight chance PoPs Monday
for the southwest half of the forecast area, gradually spreading
northeast Monday night and covering the entire area on Tuesday.
The front will move off the coast Wednesday morning with drier and
cooler air filtering in behind it for Thursday into the weekend.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Short Term /Through 00Z Monday/...
As of 655 PM Saturday, VFR conditions will persist until patchy
stratus arrives behind cold front around 08z through about midday
Sunday. Should return to VFR Sunday afternoon as drier air filters
in from the north.
Long Term /Sunday night through Thursday/...
As of 3 PM Sat...Isolated showers possible Monday. Scattered
showers and storms Tuesday, with isolated showers possible
Wednesday. Surface winds from the NE 5-10 Sunday, E around 5 knots
Monday, S around 5 knots Tuesday and NE around 5 knots Wednesday.
&&
.MARINE...
Short Term /through Sunday/...
As of 1005 PM Saturday, Small Craft Advisory remains in place from
Ocracoke northward as gusty N/NNE winds are now increasing behind
cold front as it slowly progresses into our far northern counties
this evening and should move south overnight. Seas continue at 4-6
feet with some long period swell energy from distant Tropical
Cyclone Karl, running 10-12 seconds. Expecting NE winds 15-20
knots tonight, then 10-20 knots Sunday, diminishing to 10-15 kt
late afternoon.
Long Term /Sunday night through Thursday/...
As of 3 PM Sat...Pressure gradient through the period will not be
very tight, with wind speeds no higher than 10-15 knots. Winds
will steadily veer Sunday night through Tuesday, with the high
moving off to the east on Monday and a cold front approaching from
the west Tuesday. The front will move off the coast Wednesday
morning, with a NE flow setting up across the area behind it. Seas
will average 3-5 feet Sunday night, and 2-4 feet Monday through
Thursday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement through Sunday afternoon for NCZ095-
103-104.
MARINE...Small Craft Advisory until 1 PM EDT Sunday for AMZ150-152-154.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...HSA
AVIATION...CTC/HSA
MARINE...CTC/CQD/HSA
Area Forecast Discussion
National Weather Service Melbourne FL
900 PM EDT SAT SEP 24 2016
.DISCUSSION...
...Lingering swells will keep the Rip Current risk at area beaches
elevated Sunday...
Update...
Afternoon/evening convection has died down over eastern
side of state with some residual breeze collision activity over the
west. Past several nights have featured additional convection well
into the evening due to the very moist airmass in place and boundary
interactions over areas that did not receive much TS activity
earlier in day. Some short range models including HRRR and local 1km
version of the WRF show the potential for this to occur again over
the interior of the southern counties late this evening. Will
monitor potential on radar before releasing update to potentially
include later evening pops. Otherwise forecast on track.
&&
.AVIATION...Convection has dropped off and expect VFR conditions
overnight with light winds. More TS developement Sunday afternoon
mainly between 18-21Z near coast and after 21Z over interior.
&&
.MARINE...
Tonight/Sunday...NE-E winds 5-10 knots expected with an E to NE
swell of 3-4 ft near shore and 4-5 ft well offshore. Scattered
showers/storms expected mainly south of Cocoa Beach Sunday.
&&
.MLB Watches/Warnings/Advisories...
FL...None.
AM...None.
&&
$$
Blottman/Kelly
Area Forecast Discussion
National Weather Service Blacksburg VA
944 PM EDT Sat Sep 24 2016
.SYNOPSIS...
Cold front arrives from the north tonight, moving south into the
Carolinas Sunday, before stalling. High pressure following the
front will wedge south along the eastern slopes of the mountains
Sunday into early Monday. Another cold front will shift in from
the west Monday night into Tuesday bringing better chances of
showers and isolated thunderstorms for early next week.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 945 PM EDT Saturday...
Backdoor front looks to be making slow progress through the
forecast area along a line near BLF through to Halifax County VA. Not
many changes required. Adjusted temperatures to be more
reflective of current conditions but overnight lows seem on track
based on LAMP guidance. Slight adjustments made to the sky based
on current METSAT but otherwise still looking to be a bit cloudy
out east. Chances for isolated drizzle still exist for areas east
of the Blue Ridge therefore POPs remain unchanged.
As of 745 PM EDT Saturday...
Backdoor front appears to be near a near a SHD to LYH line at this
hour. Winds have shifted to the northeast at LYH. Expect front to
continue sagging southwest through the evening. Mid-level clouds
accompany the front with lower clouds in northern VA. As easterly
flow evolves across the region behind the front, expect clouds to
continue to increase with patchy drizzle and/or light rain
developing especially in upslope areas near the Blue Ridge. A few
showers have been noted along the front over the past few hours in
the southern Shenandoah Valley. HRRR generally dissipates these,
so thinking most precipitation overnight/early Sunday will come
from upslope enhanced drizzle.
Temperatures still well above normal at this hour, which required
some adjusting upwards. However, dewpoints were on track. Minor
modifications made to pops, nothing significant.
As of 230 PM EDT Saturday...
A cold front, currentLY over northern Virginia, will edge toward
the area this evening then slide to the south into the Carolinas
tonight. Low deck clouds will accompany the front with a few
prefrontal dark base clouds producing a few sprinkles late this
afternoon. Low level flow remains northeasterly which should limit
chances for measurable precipitation for the next 24 hours.
However, moisture is shallow (under 4 kft), but will remain thick
and overcast through the day Sunday. With some weak warm air
advection, isentropic lift and flow turning more easterly on
Sunday, light rain/drizzle is possible along eastern slopes of the
Blue Ridge.
As the front moves to the south, cool air and cloudy conditions will
keep temperatures on the cool side for the next 24 hours or so.
Considering the depth of the wedge is around 3000 to 4000 feet, just
about everyone will see cooler than normal temperatures Sunday.
Temperatures will only warm into the 70s with eastern slopes likely
to stay in the 60s. The Bluefield-Richlands area will be on the
western flank of the wedge and could see some erosion in the
afternoon. A warm upper level ridge over the southern Mississippi
Valley could stretch east into area, allowing southwest Virginia to
warm to near 80F.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 245 PM EDT Saturday...
Low level wedge looks to be at its strongest Sunday night into early
Monday with the axis of the surface high just east of the mountains
aided by continued light rain/drizzle across the west and shortwave
ridging aloft. Guidance even suggests that some drier air from the
northeast could work into eastern sections during the evening given the
strength of the high, allowing for brief clearing before the flow
aloft starts to turn more southwest overnight. This should once
again propel the shield of low clouds back east by early Monday
with lingering low pops for light rain/drizzle espcly Blue Ridge
and points west into midday Monday. Lows mostly 50s to lower 60s
Sunday night with coolest air over the north/northeast.
Wedge should begin to scour out Monday afternoon as ridging aloft
flattens in advance of the strong upstream upper trof that will push an
associated cold front toward the mountains by late in the day. Models
also show quite an increase in moisture depth ahead of the front with
PWATS near 2 inches under decent southwest flow aloft. This deepening
flow looks to gradually weaken the wedge from west to east by Monday
evening although far northeast sections may not see the cool pool
exit until overnight when the pre-frontal showers arrive. However
does appear to be enough instability and added focus as the warm
front lifts north and the pre-frontal lobe enters, to support some
low chance thunder mainly south/west late Monday, with more
widespread shower coverage progressing east during the overnight.
Latest ensembles as well as a mix of the GFS/EC also support a
swath of around one half to as much as one inch of qpf espcly
central/eastern sections. Therefore running with a period of high
chance to low likelys from west to east starting late Monday
mountains and out east into early Tuesday.
Boundary may slow enough during Tuesday given the stalling nature of the
strong upper low to the north, to linger some shower pops eastern
sections, with more clearing developing mountains by afternoon. Stayed
with cooler highs Monday, 70-75, except perhaps near 80 far west where
will exit the wedge sooner. Appears enough cool advection to hold much
of the mountains in the 60s to around 70 Tuesday espcly if clouds
persist longer, with the east mainly mid 70s pending how soon the
showers end.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 145 PM EDT Saturday...
Upper low/trof should push east across the mid-Atlantic during midweek
with its associated cold front exiting the region to start the period.
However latest model trends suggest a somewhat slower scenario with
lots of uncertainty in just how fast this will happen given the slow
evolution of this complex upper system to the north. Based on current
and still rather progressive model solutions, could still be looking at
a few evening showers southeast Tuesday night as the front perhaps
slows per added low pressure rippling northeast. Also passing of the
center of the 500 mb trof axis/cold pool may also generate a few
showers mainly northern/western sections late Wednesday into early
Thursday but iffy. Otherwise should see much drier air invade the area
as ridging both surface and aloft take control from later Thursday into
next weekend. Expect mostly seasonal temps with highs 60s west to 70s
east with coolish overnights with some 40s mountains and 50s elsewhere.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
As of 745 PM EDT Saturday...
Deteriorating conditions expected through the TAF valid period as
a backdoor front continues to sag southwest through the CWA.
Upslope maritime flow will develop overnight into Sunday promoting
the development of widespread low clouds, hence MVFR cigs with
brief periods of IFR cigs possible Sunday morning. VFR conditions
should prevail through the remainder of Saturday evening, although
mid clouds will increase across the area from northeast to
southwest.
For Sunday, widespread MVFR cigs are expected through early to
mid-afternoon in the developing wedge improving, especially in
northeastern areas by mid-afternoon to VFR as drier air begins to
advect southwest into the region. Expect MVFR cigs to hold much of
the day in the southwest and west parts of the forecast area,
including KBCB and KBLF.
Fog development overnight is in question and at this point nothing
much worse than MVFR is expected. Clouds may prevent much fog
development at all, however upslope easterly flow could promote
development of MVFR BR along and near the Blue Ridge during the
late night/early morning hours Sunday. Spotty drizzle could also
develop at locations such as KBCB and KROA by morning.
Winds will be light northwest west and south of the front,
becoming northeast around 5 mph to the north of the backdoor
front.
Extended aviation discussion...
The backdoor front will drift to just south of the area by Sunday
night and stall. Overrunning will begin in earnest Sunday night
into Monday in advance of a strong, but slow moving, cold front
that will approach the area from the west late Monday. A healthy
line of showers and a few thunderstorms can be expected in advance
of the front as it moves through the region during this time
frame. Widespread sub-VFR cigs/vsbys are expected in the wedge air
mass Monday before the front arrives, which will also be
accompanied by a period of sub-VFR cigs/vsbys. Conditions will
improve by midweek, although as an upper low sinks southward over
the Appalachians, conditions could become unsettled enough to
continue periods of sub-VFR cigs and scattered showers.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...JH
NEAR TERM...JR/RAB/RCS
SHORT TERM...JH
LONG TERM...JH
AVIATION...RAB/RCS
Area Forecast Discussion
National Weather Service Tallahassee FL
857 PM EDT SAT SEP 24 2016
.UPDATE...
No updates were necessary to the overnight forecast.
&&
.PREV DISCUSSION [731 PM EDT]...
.NEAR TERM [Through Tonight]...
The 8 am EDT regional surface analysis showed a broad area of higher
pressure across much of the Southeast. Vapor imagery and upper air
data showed a strong ridge from the central Gulf Coast to the upper
Midwest, but there was a weak minimum in the height/temperature
fields centered over Tallahassee. The latest RAP analysis did not
show any Q-G forcing associated with this low. Isolated to scattered
thunderstorms have been developing early this afternoon, but most
have been dissipating quickly once they grow into the dry zone
aloft. We expect isolated storms to continue through the afternoon,
mainly near the coast. It`s interesting to note that a few of the
storms today have had a tremendous amount of lightning. Any
remaining storms from this afternoon will dissipate by evening,
though isolated storms will develop offshore toward dawn. Overnight
lows will be in the lower 70s.
.SHORT TERM [Sunday Through Monday Night]...
An upper level low positioned across the western part of the CWA is
expected to move slightly west on Sunday, and then shift eastward on
Monday. The movement of this low will begin to sink a cold front
into the southeast. Ahead of this cold front, winds will shift east
on Sunday and there will be an increase in moisture. A slightly more
active day in terms of coverage can also be expected on Monday, with
PoPs around 30-50%. High temperatures will remain above normal
through the period, with highs in the low 90s inland and upper 80s
along the coast.
.LONG TERM [Tuesday Through Saturday]...
An upper level trough will amplify over the eastern CONUS Tuesday
and move off the Atlantic seaboard on Thursday. The associated weak
cold front will sweep across the CWA Tuesday/Tuesday night with
surface high pressure and drier airmass filtering in Wednesday
through the beginning of next weekend. Dew points are forecast to
drop into the upper 50s to lower 60s across all but the coastal areas
and southeast Big Bend. Pops will be highest on Tuesday (albeit
only 30%). Highs will be in the upper 80s.
.AVIATION [Through 00Z Monday]...
Isolated showers and thunderstorms continue to dissipate across
our area this evening, with VFR conditions expected along with
light and variable winds. VLD and TLH could see patchy low clouds
or fog around sunrise, but chances appear fairly low at this time.
Scattered showers and thunderstorms may develop across our area
from Sunday afternoon through the early evening, with highest
chances across the FL Panhandle. However, VFR conditions will
continue to prevail, with very brief visibility reductions
possible in showers or storms.
.MARINE...
Winds are expected to be light (less than 10 knots) and variable
through the middle of the week, with seas around one foot.
.FIRE WEATHER...
No problems.
.HYDROLOGY...
While rain is expected over the next few days, significant
rainfall amounts are not expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 91 72 90 71 / 10 30 20 40 20
Panama City 76 88 74 86 74 / 10 40 20 30 20
Dothan 71 92 70 90 69 / 10 30 20 20 20
Albany 71 92 70 90 70 / 0 20 10 30 20
Valdosta 71 90 70 88 69 / 10 20 20 50 20
Cross City 72 90 71 88 70 / 10 20 20 30 20
Apalachicola 75 87 74 85 74 / 10 30 20 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...Harrigan
NEAR TERM...Fournier
SHORT TERM...Barry/King
LONG TERM...Barry
AVIATION...Lahr
MARINE...Barry/King
FIRE WEATHER...Harrigan
HYDROLOGY...Fieux
Area Forecast Discussion
National Weather Service Binghamton NY
225 AM EDT Sun Sep 25 2016
.SYNOPSIS...
Cool Canadian high pressure remains in charge, with below normal
temperatures yet also plenty of sunshine expected to round out
the weekend. Frost is possible for some locations early this
morning and again Monday morning. After slightly milder weather
Monday, our next system will sweep west to east through the region
Monday night with a round of showers.
&&
.NEAR TERM /THROUGH TONIGHT/...
2 AM update...
Forecast mostly going as expected except that a band of lake
effect clouds developed in Central New York just prior to
midnight. Motion in infrared satellite imagery, and the 925mb RH
field in the RAP model for the next several hours, suggests that
these scattered clouds will drift across the Finger Lakes region
to Norwich and Binghamton, then shift more towards the Central
Southern Tier while dissipating towards dawn. These clouds have
been just enough to hold back temperatures from dropping as much
compared to surrounding clear areas. While some parts of the Frost
Advisory counties may skip out from getting a widespread frost
thanks to the brief addition of scattered lake clouds,
temperatures Otsego-Madison-Delaware counties are still already in
the 36-40 degree range according to mesonet obs so those areas
will likely still have a fair amount of frost. Besides, another
chance for it will come tonight.
A quiet day is foreseen as the Canadian high pressure settles
over the area. Crisp air and plenty of sunshine, with below normal
highs in the upper 50s to mid 60s. Dewpoints will drop into only
the lower to mid 30s this afternoon.
The center of the broad high pressure will position itself over
interior New England tonight. High thin cirrus will begin to
spread into the western parts of our area late tonight, but
overall we are looking at a solid night of radiational cooling and
thus another threat for frost. Closer to the high pressure center,
the Tug Hill to Catskills to Poconos areas will be particularly
prone, and another Advisory may end up being needed. Further west
and especially Finger Lakes to Central Southern Tier, there will
be developing light southerly return flow on the back side of the
high, along with thin clouds late. So eventual lows of upper 30s-
lower 40s will be more common, though temperatures will be quick
to drop this evening. Frost, if any, will tend to be very patchy
for the western zones.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Main focus for this part of the forecast will be a frontal system
which will bring a period of rain and showers as it moves across
the area west to east Monday night. However to start the day
Monday, conditions will be quite cool, especially in the east
closer to the center of the departing high. This high will
continue to shift off to the east through Monday with increasing
mid and high clouds as the frontal system approaches from the
west. Southerly winds will also become quite gusty by afternoon
due to the increasing gradient. This will help bring in warmer air
with highs generally in the mid to upper 60s. Expect most of the
day to be dry as forecast models are in pretty good agreement that
any precip holds off until at least 21z at which time we introduce
low chances for showers over the west.
For Monday night, expect an area of rain and showers ahead of a cold
front to move into the region from the west beginning near or just
after 0z. Since the warm sector associated with this system will
be occluding out to our south, instability doesn`t look to be much
so scaled back the chance of thunder to mainly just the western
southern tier into NE PA. Precip will continue to push east
through the late evening into the overnight and should be mostly
cleared out of the region to the east by Tuesday morning. Total
rain amounts look to be generally around a quarter inch or so.
For Tuesday, the area of low pressure associated with the above
mentioned frontal system becomes vertically stacked under a large
upper low over the Great Lakes while the low`s cold front will be
off to our east. This will leave the area mostly in a relatively
dry wedge under a W/SW flow with a mix of sun and clouds. There
will be the chance for a few scattered showers primarily over
extreme N/W portions of the CWA but otherwise expect the day to be
largely rain free with highs in the 60s. Little change occurs
heading into Tuesday night with lows in the 40s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
220 AM Update...Tricky long range forecast as there is
uncertainty regarding the speed and evolution of the upper low
that will be off to our west over the Great Lakes to begin the
period. General trend in the models, however, is for this system
to be slower to move through. This could result in unsettled
weather lasting longer into the long range period. With this
update, loaded in the latest Superblend and the main forecast
change was to raise POPs slightly for most days.
Saturday PM Update...Conditions through the rest of the week will
remain cool and unsettled with a persistent northwesterly flow in
place across much of the region. A large area of low pressure
aloft will be situated near the Great Lakes and rotate slowly to
the east through the week ushering in a continuous supply of cool
Canadian air. As this air mass moves over the very warm waters of
Lake Ontario...expect the usual fall-type conditions with
temperatures slightly below average...plenty of clouds low chances
of on and off rain showers. Will likely not see much in way of
daily temperature fluctuations with the cloud cover keep temps
cool during the day and relatively warm at night. Highs will
generally top out in the 60s...with overnight lows in the upper
40s and 50s.
Will start to see an end to this pattern toward Friday as the upper
low moves to the east and high pressure begins to build in from the
west. Temperatures will inch upwards a few degrees going into the
weekend.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
VFR through the TAF period except for small window of valley fog
at KELM. What looked like a sure thing for KELM is a bit less
certain now for valley fog this morning. Scattered lake effect
clouds unexpectedly developed around 03Z in Central NY near KSYR-
KRME. This 5-6 kft agl scattered deck will drop south over KITH-
KBGM- KELM 06Z-10Z, which may hold back fog development some for
KELM. Still, as those clouds dissipate towards dawn, we still
expect VIS to fluctuate in-and-out of IFR range at times from 10Z-
13Z. Other than that, Canadian high pressure in charge with mainly
clear sky through 00Z, then a few very high thin clouds starting
to move in from the west 00Z-06Z Monday.
OUTLOOK...
Monday...Mainly VFR.
Monday Night-Early Tuesday...A period of restrictions likely as a
frontal system moves through with showers.
Tuesday afternoon-Thursday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Frost Advisory until 8 AM EDT this morning for NYZ009-036-037-
045-046-057-062.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...PCF
LONG TERM...BJT/PCF
AVIATION...MDP
Area Forecast Discussion
National Weather Service Wilmington NC
339 AM EDT Sun Sep 25 2016
.SYNOPSIS...
A backdoor cold front will stall across the area today before
lifting back to the north on Monday. This will create periods of
showers and isolated thunderstorms through Monday. A stronger cold
front will move across the Carolinas late Tuesday and Wednesday
with continued chances for showers. Cooler temperatures are
expected behind this front for late in the week and into next
weekend as high pressure builds southward from Canada.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Sunday...A backdoor cold front was positioned from near
RDU to MHX. This front will move slowly south and is expected to
push into the forecast area this morning. The front is currently
being nudged to the south by high pressure across the Great Lakes
and northeast states. The center of the high is expected to move
across New England tonight. The front will likely get hung up as it
tries to push through the the forecast area today and should stall
in close proximity tonight before drifting back to the N late
tonight and Mon. Low clouds across northeast NC will continue to
push south behind the front and we expect clouds to be on the
increase today, especially across NC. Still a fair amount of dry air
in the mid-levels today. Moisture will be increasing below 25 kft or
so. Instability will be increasing with mixed layer CAPE values
peaking this afternoon in the 800 to 1200 J/kg range, highest across
SC. There is no appreciable upper level support and the high
resolution HRRR is not showing any convection developing until mid
afternoon. Will show POPs increasing above threshold early to mid
afternoon and include isolated thunderstorms by mid afternoon and
into early this eve. Depth of moisture should largely preclude heavy
rainfall amounts despite the slow storm motions.
Given the proximity of the front, will keep a mention of showers in
the forecast through the eve and overnight, but the moisture
depth will be restricted to about the lowest 15 kft of the column
and so will pull any mention of late night thunderstorms.
Highs today will be in the lower to mid 80s, warmest across the
Pee Dee. Lows tonight, mid 60s to lower 70s.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...High pressure across New England will drift
offshore and this will allow the cold front to push back N of the
area during the day with surface winds turning onshore and
eventually to the SE Mon afternoon and eve. A subtle mid-level
shortwave will sneak up the coast late in the day Mon and Mon night.
A vigorous trough carving out across middle America is expected to
drive a cold front into and eventually through the eastern Carolinas
Tue night or Wed. Moisture will increase steadily during Tue and Tue
eve and then begin to drop off sharply with frontal passage
overnight, lastly along the coast Wed. Will show convection through
the period, but include the highest probability Tue afternoon and
night.
Highs will be about normal, lower 80s. Lows will be in the upper 60s
to lower 70s Mon night and then cooling in the wake of the cold
front to mid and upper 60s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 300 AM Sunday...Deep upper low will evolve across the Great
Lakes and then sink slowly SE through late week before ejecting into
Canada during the wknd. This will drive a cold front across the
Carolinas on Wednesday, but its overall progression is a low
confidence forecast due to model uncertainties into the evolution of
the aforementioned upper low. ECM is deeper and stronger with this
upper low, cutting it off entirely from the mean flow into next
wknd. The CMC is the fast solution with short cutoff followed by
rapid progression into the westerlies by late week. The GFS is a
decent compromise, although its ensembles show a very large spread
by D6. The biggest difference to the sensible weather from these
solutions revolves around precip potential, as temperatures will
likely be seasonable or slightly below regardless of which outcome
is correct.
Will favor the GFS attm which is supported by WPC, which
suggests the front will push offshore as the upper low begins to
move NE Thursday, with cool high pressure building down the coast
thereafter. Temperatures Wed/Thu will likely be around seasonable
norms or slightly above, but clouds and showers will be likely as
the front drifts towards, and then off, the SE coast. As the high
builds south late week and into Saturday, temps will cool to below
normal with mins potentially dropping to 60 or below, especially
inland, by the end of the period. If the ECM solution ends up being
correct, temperatures will still follow this trend, but both Friday
and Saturday could also feature periods of showers instead of the
drier forecast currently being shown.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
As of 06Z...Back door cold front approaching from the NE will drop
slowly SW overnight, bringing increasing stratus to the terminals.
LBT/ILM are most likely to experience stratus overnight, with short
duration IFR expected before becoming predominantly MVFR through
daybreak. The SC terminals will have FROPA after dawn, so only some
sct stratus is expected. However, all terminals have a chance for
some fog ahead of this back door front, and a few sites have already
dropped to MVFR around the area. Best chance for IFR fog is at CRE,
but the inland terminals may also see IFR vsbys towards daybreak.
Winds will be calm, becoming light from the NE late.
After daybreak, fog/stratus will lift but the cold front will stall,
likely across SC. This will create a chance for showers through the
day at all terminals, but attm no thunderstorms are expected. Winds
will become E/NE around 10 kts, and VFR is forecast with any
restrictions confined to tempo MVFR in showers. More stratus is
possible Sunday night, and have reintroduced MVFR at all
terminals at the end of the valid period.
EXTENDED OUTLOOK...Chance for SHRA/TSRA each day through Wed.
Otherwise expect VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Sunday...A backdoor cold front will move into the
northern waters this morning and will likely stall across the
southern waters this afternoon and eve before moving back to the N
tonight and Mon. High pressure will be moving into and through the
northeast states today and tonight and then offshore Mon. Winds
across our coastal waters will be from the NE through the period at
speeds of up to 15 to 20 kt. Seas will be mainly 3 to 4 ft, but up
to 5 ft around Frying Pan Shoals in part due to a robust 9 to 11
second easterly swell.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...High pressure across New England will move
offshore and this will allow winds to shift from NE and ENE Mon
morning to E Mon afternoon and to SE Mon night. As a cold front
approaches the waters, SE winds Tue will become S and SW Tue
night. If the front does not slow down, winds may shift to the N
as early as the wee hours of Wed morning. The highest winds this
period will be Mon and Mon eve, up to 10 to 15 kt. Seas of 3 to 4
ft Mon and Mon night will subside to 2 to 3 ft Tue and Tue night.
LONG TERM/WEDNESDAY THROUGH THURSDAY/...
As of 300 AM Sunday...Some uncertainty exists in the extended with
respect to the timing of a cold front moving across the waters, but
attm it appears the front will stall over the waters Wednesday and
then shift well offshore during Thursday. This leaves a period of
highly variable winds on Wednesday with speeds of 5-10 kts, before
the front moves away Thursday followed by N to NE winds of 10-15
kts. Seas Wed and most of Thu will be 2-3 ft with residual 11-12 sec
swell remaining in the spectrum combined with low-amplitude wind
waves. Late in the period a northerly 4-5 sec wave will amplify, and
seas may build towards 3-4 ft late Thursday.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...JDW
NEAR TERM...RJD
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...JDW
MARINE...RJD/JDW
AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
415 AM CDT SUN SEP 25 2016
.SHORT TERM...
Upper level ridge that encompasses most of the southeastern United
States is beginning to compress and weaken as a trough is moving
northeast across the high plains. The weakening of the ridge will
allow for scattered convection to develop and become slightly more
widespread today. Surface analysis shows a weak inverted trough
developing over southern Mississippi and Alabama. This correlates
perfectly with the general location where the HRRR suggests
thunderstorms will initiate this afternoon. These storms should move
southwest into the CWA along the MS/LA border before dissipating as
they track across the Florida Parishes. The latest forecast pops
were adjusted to represent expected convection. Those rain chances
are slightly above the previous forecast and what neighboring
offices have. Highs will be about the same as yesterday in the lower
90s which is several degrees above normal.
.LONG TERM...
The ridge overhead will continue to suppress Monday which will allow
the trough to the north to dig further south. Rain chances should
remain in the low end change category as the first significant
cold front since last spring approaches the region. A reduction in
500 mb heights will result in high temps struggling to reach 90.
The upper trough will slowly push east while spreading south over
the southeast conus through Thursday. Much cooler and drier air will
surge south across the CWA during those days. Expect fall like
temperatures with highs in the lower to mid 80s and lows in the
upper 50s to lower 60s. These conditions could stretch into the
weekend albeit some air mass modification.
Meffer
&&
.AVIATION...
Generally VFR conditions will prevail through Sunday morning. A few
hours of lower cigs and vsbys will be possible around sunrise and
TEMPO groups have been included for the KHUM and KMCB. A sct cu
field is expected between 3 and 4kft by late morning and isolated
convection in the afternoon but too isolated to mention in taf
forecast for now. 18
AVIATION...
General VFR conditions expected all terminals through Monday
morning. KHUM and KMCB may see some localized light fog formation in
areas prone to drainage aspects near daybreak, but should be limited
in extent and duration. Isolated showers and thunderstorms will
occur this afternoon but too isolated to mention in taf
forecast...so will handle within 6 hours. 18
MARINE...
Light winds and low seas in a flat pressure gradient are expected
through Monday. Frontal passage expected into the gulf waters Monday
night to bring a moderate increase in offshore flow as cooler and
drier air builds into the north gulf. The continental high will then
settle over the eastern CONUS and moderate slowly throughout the
week while winds veer to a more easterly flow by mid-week. A
secondary surge may push through the coastal waters on Thursday. 18
DECISION SUPPORT...
DSS code: Green.
Deployed: None.
Activation: None.
Activities: None.
Decision Support Services (DSS) Code Legend
Green = No weather impacts that require action.
Blue = Long-fused watch, warning, or advisory in effect or
high visibility event.
Yellow = Heightened impacts with short-fused watch, warning
or advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby
tropical events; HazMat or other large episodes.
Red = Full engagement for Moderate risk of severe and/or
direct tropical threats; Events of National Significance.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 93 71 91 67 / 30 20 30 20
BTR 92 72 91 69 / 20 20 30 20
ASD 92 73 91 71 / 30 20 30 20
MSY 92 75 90 75 / 20 20 30 20
GPT 91 75 90 72 / 30 20 30 20
PQL 91 73 89 72 / 30 10 30 20
&&
.LIX Watches/Warnings/Advisories...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Lubbock TX
1157 PM CDT SAT SEP 24 2016
.AVIATION...
Showers have edged east of TAF sites momentarily but a new area
of showers with thunder a bit further south was developing over
the eastern Permian Basin into the Big Country and appeared
expanding north-northeast. Latest projections edge this area
northward overnight while also developing more activity back
westward near both KLBB and KPVW. Then, solutions are fairly
consistent with the arrival of the main frontal boundary into the
area mid to late Sunday morning. We have adjusted for showers a
bit earlier later tonight, then added thunder for the frontal
passage from just before to a little after noon. Expect showers
should be mostly favored into the mid and late afternoon though
drier low level air will be moving southward and could diminish
activity at least somewhat from north to south by late afternoon
into Sunday evening though solutions are not very clear or in
decent agreement on this. Also, we are already seeing very low
dewpoint depressions near KPVW and current HRRR indicates a risk
of fog early this morning. Some threat of IFR conditions but not
overwhelming signals to that effect, so have hinted at lower
ceilings at least but leaving outright mention out for now.
RMcQueen
&&
.PREV DISCUSSION... /issued 648 PM CDT SAT SEP 24 2016/
AVIATION...
Current convective activity lined up along a weak Pacific cold
front/surface trough edging through the Rolling Plains with
showers still impacting KCDS as late as 02z perhaps. Then, we
should experience a lull in showers impacting the TAF sites anyway
until activity bulging northward early Sunday interacts with a
Canadian cold front moving in not long after daybreak. We have
made no significant changes at this point as Sunday still looks
like a bleak day with uncertain ceilings somewhere in the MVFR
range plus or minus and plenty of showers. Thunder looks like a
possibility as well and with the arrival of the 00z solutions in
the next few hours will allow reassessment for the 06z package.
RMcQueen
PREV DISCUSSION... /issued 344 PM CDT SAT SEP 24 2016/
SHORT TERM...
We have seen widely scattered showers and thunderstorms roaming a
good chunk of the CWA (all but the western zones) through the day
today. This activity has more recently shifted into the Rolling
Plains ahead of a weak surface trough near the I-27 corridor and
within the deeper moisture caught up in the modest southwesterly
flow aloft. Afternoon heating has resulted in MLCAPE values of 1500-
2500 J/kg off the Caprock and this has helped to fuel an increase in
storm coverage and intensity, and we will continue to see the
potential to a few strong to marginally severe storms into the early
evening hours. In addition, PWATs in excess of 1.6 inches will
support very heavy rain rates, with the risk for minor flooding
where cells can train a bit. However, relatively quick storm motions
should preclude a more widespread flooding threat this evening. In
fact, the bulk of this activity may shift east of the CWA this
evening, though at least the southeast most zones may see the storm
and heavy rain threat persist.
After a bit of a lull in activity this evening, a developing upper
low centered over southeast Arizona and southwest New Mexico late
tonight and associated lower-level circulation near the Big Bend
will help to draw moisture back northwestward while also increasing
lift locally. As such, shower and thunderstorm coverage will expand
northwestward late tonight into Sunday morning. Attention will also
turn northward to a cold front that will be sweeping southward and
will move through the South Plains during the morning and early
afternoon. 850-700 mb convergence is progged to setup for period
across the southeast South Plains into the Rolling Plains and this
may lead to another round of locally heavy rainfall. Depending how
much rain this area receives through tonight, a flooding threat
could develop, but current thinking is that it should generally be
nuisance type flooding. We will continue to watch this though for a
possible more widespread heavy rain threat. Elsewhere, light to
moderate rain is expected north of the front along with gusty
northeasterly winds and relatively chilly temperatures. Plenty of
cloud cover and rain will make it difficult for highs to climb out
of the 60s, though morning lows will not be that much cooler (except
northwest where it may drop into the 50s again). Precipitation
intensity and coverage will begin to fade from north to south
through the afternoon hours as lift weakens and drier low-level air
invades.
LONG TERM...
Precipitation is expected to continue into Sunday evening favoring
the southern zones. However, with lift diminishing through the
night as the parent upper level low retrogrades westward across
Sonora, precipitation will begin to taper off. This trend
continues into Monday, although the setup may favor some afternoon
showers depending on the degree of warming. Along those lines,
quite a bit of relatively low mid cloud expected, but the lack of
low cloud will support increasing high temperature forecast for
Monday.
The rest of the extended looks fairly quiet. Upper level ridging
Tuesday will begin to dry things out and warm temperatures. Not
as much energy is progged to be ejected from the southwestern
CONUS when the retrograded low finally gets kicked out midweek.
Could see a few storms toward next weekend depending on evolution
of a trough out west, but not much to hang your hat on at this
point.
&&
.LUB Watches/Warnings/Advisories...
None.
&&
$$
99/99/05
Area Forecast Discussion
National Weather Service Binghamton NY
1050 AM EDT Sun Sep 25 2016
.SYNOPSIS...
Cool Canadian high pressure remains in charge, with below normal
temperatures yet also plenty of sunshine expected to round out
the weekend. Frost is possible for some locations early this
morning and again Monday morning. After slightly milder weather
Monday, our next system will sweep west to east through the region
Monday night with a round of showers.
&&
.NEAR TERM /THROUGH TONIGHT/...
11 AM update...
No significant changes made to the forecast. Still expecting areas
of frost tonight/Monday morning across the Catskills...portions of
the Mohawk Valley...and the Tug Hill Plateau. So, a Frost Advisory
has been issued for these areas tonight.
645 AM Update...
The scattered lake effect clouds have dissipated as expected,
though they took long enough to hold back a bit on the fog
development in the Elmira area. Sidney-Norwich meanwhile had a
long enough clear period for dense valley fog. Infrared imagery
suggests valley fog also in the Susquehanna Valley in Bradford-
Wyoming Counties of PA. As for frost, temperatures throughout the
advisory counties have indeed managed to get into the mid to upper
30s. A few mesonet sites are even close to freezing such as Cherry
Valley and Cooperstown in Otsego County and Sherburne. Outside of
the advisory zones there are sporadic upper 30s in the Southern
Tier/Ithaca/Cortland areas and so patchy frost is probably
occurring for those areas.
Previous discussion...
Forecast mostly going as expected except that a band of lake
effect clouds developed in Central New York just prior to
midnight. Motion in infrared satellite imagery, and the 925mb RH
field in the RAP model for the next several hours, suggests that
these scattered clouds will drift across the Finger Lakes region
to Norwich and Binghamton, then shift more towards the Central
Southern Tier while dissipating towards dawn. These clouds have
been just enough to hold back temperatures from dropping as much
compared to surrounding clear areas. While some parts of the Frost
Advisory counties may skip out from getting a widespread frost
thanks to the brief addition of scattered lake clouds,
temperatures Otsego-Madison-Delaware counties are still already in
the 36-40 degree range according to mesonet obs so those areas
will likely still have a fair amount of frost. Besides, another
chance for it will come tonight.
A quiet day is foreseen as the Canadian high pressure settles
over the area. Crisp air and plenty of sunshine, with below normal
highs in the upper 50s to mid 60s. Dewpoints will drop into only
the lower to mid 30s this afternoon.
The center of the broad high pressure will position itself over
interior New England tonight. High thin cirrus will begin to
spread into the western parts of our area late tonight, but
overall we are looking at a solid night of radiational cooling and
thus another threat for frost. Closer to the high pressure center,
the Tug Hill to Catskills to Poconos areas will be particularly
prone, and another Advisory may end up being needed. Further west
and especially Finger Lakes to Central Southern Tier, there will
be developing light southerly return flow on the back side of the
high, along with thin clouds late. So eventual lows of upper 30s-
lower 40s will be more common, though temperatures will be quick
to drop this evening. Frost, if any, will tend to be very patchy
for the western zones.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Main focus for this part of the forecast will be a frontal system
which will bring a period of rain and showers as it moves across
the area west to east Monday night. However to start the day
Monday, conditions will be quite cool, especially in the east
closer to the center of the departing high. This high will
continue to shift off to the east through Monday with increasing
mid and high clouds as the frontal system approaches from the
west. Southerly winds will also become quite gusty by afternoon
due to the increasing gradient. This will help bring in warmer air
with highs generally in the mid to upper 60s. Expect most of the
day to be dry as forecast models are in pretty good agreement that
any precip holds off until at least 21z at which time we introduce
low chances for showers over the west.
For Monday night, expect an area of rain and showers ahead of a cold
front to move into the region from the west beginning near or just
after 0z. Since the warm sector associated with this system will
be occluding out to our south, instability doesn`t look to be much
so scaled back the chance of thunder to mainly just the western
southern tier into NE PA. Precip will continue to push east
through the late evening into the overnight and should be mostly
cleared out of the region to the east by Tuesday morning. Total
rain amounts look to be generally around a quarter inch or so.
For Tuesday, the area of low pressure associated with the above
mentioned frontal system becomes vertically stacked under a large
upper low over the Great Lakes while the low`s cold front will be
off to our east. This will leave the area mostly in a relatively
dry wedge under a W/SW flow with a mix of sun and clouds. There
will be the chance for a few scattered showers primarily over
extreme N/W portions of the CWA but otherwise expect the day to be
largely rain free with highs in the 60s. Little change occurs
heading into Tuesday night with lows in the 40s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
220 AM Update...Tricky long range forecast as there is
uncertainty regarding the speed and evolution of the upper low
that will be off to our west over the Great Lakes to begin the
period. General trend in the models, however, is for this system
to be slower to move through. This could result in unsettled
weather lasting longer into the long range period. With this
update, loaded in the latest Superblend and the main forecast
change was to raise POPs slightly for most days.
Saturday PM Update...Conditions through the rest of the week will
remain cool and unsettled with a persistent northwesterly flow in
place across much of the region. A large area of low pressure
aloft will be situated near the Great Lakes and rotate slowly to
the east through the week ushering in a continuous supply of cool
Canadian air. As this air mass moves over the very warm waters of
Lake Ontario...expect the usual fall-type conditions with
temperatures slightly below average...plenty of clouds low chances
of on and off rain showers. Will likely not see much in way of
daily temperature fluctuations with the cloud cover keep temps
cool during the day and relatively warm at night. Highs will
generally top out in the 60s...with overnight lows in the upper
40s and 50s.
Will start to see an end to this pattern toward Friday as the upper
low moves to the east and high pressure begins to build in from the
west. Temperatures will inch upwards a few degrees going into the
weekend.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
Valley fog can be found in several areas, but it has managed to
avoid the terminals. Lake effect clouds drifted over KELM
overnight for a long enough time to prevent fog formation. There
is still a small chance for a very brief VIS restriction at KELM
around 12Z, otherwise VFR expected for all terminals this period.
Canadian high pressure is in charge with clear sky through 00Z,
then some high thin clouds moving in tonight well ahead of our
next system.
OUTLOOK...
Monday...Mainly VFR.
Monday Night-Early Tuesday...A period of restrictions likely as a
frontal system moves through with showers.
Tuesday afternoon-Thursday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Frost Advisory from 2 AM to 8 AM EDT Monday for NYZ009-037-046-
057-062.
&&
$$
SYNOPSIS...MDP
NEAR TERM...BJT
SHORT TERM...PCF
LONG TERM...BJT/PCF
AVIATION...MDP
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1011 AM EDT SUN SEP 25 2016
.UPDATE...
Forecast largely on target. Had a quick update for a slightly
quicker cloud trend. Decent deck of altocumulus across western
Lower and Lake Michigan around 800-700 mbs. 12z DTX sounding was
very dry except in that particular layer. Latest RAP indicates
that moisture will be able to sufficiently move over the forecast
area between 18z and 22z.
&&
.PREV DISCUSSION...
Issued at 659 AM EDT Sun SEP 25 2016
AVIATION...
Looking at mostly clear skies with light southeast winds Today, with
the exception being across YIP/DTW/DET where Lake Erie moisture
contribution expected to produce some High MVFR clouds,
mixing out by afternoon. Increasing VFR clouds this evening, with
MVFR rains showers overspreading southeast Michigan Late Tonight
(8-12z) ahead of a cold front. There is a low chance of
thunderstorms as well, but not worthy of putting in TAFS.
For DTW...Potentially another High MVFR flare up of clouds this
morning. Otherwise, any low clouds mixing out by afternoon, with
just some high clouds beginning to filter in.
//DTW Threshold Probabilities...
* Low confidence in ceilings below 5000 ft this morning, High Monday
morning (12-15 Z).
* Low confidence in thunderstorms Monday morning.
PREV DISCUSSION...
Issued at 404 AM EDT Sun SEP 25 2016
DISCUSSION...
Extreme anticyclonic flow trajectories will remain in place today
over the central Great Lakes. Plan view charts show that a high
amount of localized anticyclonic vorticity advection will occur
today as an absolute vorticity structure is expected to fold before
rolling through the state. Soundings show a bulk of the subsidence
response to be confined to the 3 to 6 kft agl layer. Persistence of
dry easterly flow underneath squatty mixing heights should keep
temperatures in the lower 70s today despite the top-end subsidence
dynamics. Really a picture perfect early autumn day with high clouds
moving in during the late afternoon.
Highly amplified upper level trough and surface low pressure
reflection will push out of the northern Plains today and position
over portions of western Ontario and the upper Mississippi River
Valley by this evening. Despite some fairly wild oscillations
regarding this system in recent model runs, the guidance has
remained steadfast in the depictions for the upper level trough to
take on an extreme negative tilt here over the Great Lakes. The
tilting of the trough will turn sharply negative in response to an
upper level jet streak making the cyclonic turn an lifting
northward on the eastern flank of the trough and a stout PV maximum
or filament maintaining surprisingly very good cohesion within the
trough. Forcing for precipitation across southeastern Michigan will
come in the form of mature frontal dynamics and lower tropospheric -
div axis along the lead edge of meridional moisture transport. All
in all, the upper level synoptic scale dynamics with this system are
really not that great for southeastern Michigan. There is very poor
upper level jet support, what could be outstanding PV advection is
actually lagged off of the frontal forcing that gets shoved out
ahead of it.
The poor synoptic scale dynamics should be a major limiting factor
for the tonight and Monday morning period. High resolution guidance
is advertising a band of widespread showers and embedded
thunderstorms pushing inland into western Lower Michigan.
Thereafter, there is a strong consensus that shows convective
strength falling apart as it moves across the remainder of Lower
Michigan. Will keep thunder in the forecast due to some weak
instability - moist adiabatic lapse rates but confidence in
thunderstorms is very low. Timing for the band of showers is set
between 06-14Z beginning first across the Tri Cities. It will likely
take a some time before precipitation moves into the Detroit Metro as
the 4km Nam waits until 09-10z. Kept likely to categorical pops with
a short duration limiting QPF. No severe weather expected with
stable lower troposphere.
A decent westerly wind response is expected during the late morning
on Monday with a combination of increased postfrontal mixing and
increase lapse rates from diurnal heating. This diurnal heating will
be aided by a textbook dry slot that will be in place over Lower
Michigan for the late morning and afternoon. The data continues to
support a breezy mention with wind gusts of 30 mph supported.
A complete transition to a cutoff low is forecasted for Tuesday.
There is definitely uncertainty with exactly where the center of the
vertically stacked low pressure will be owing to the exact evolution
of the PV maximums. Expectations are low level diabatic
contributions will draw it either of Lake Superior, Lake Huron or
Lake Michigan. Latest solutions suggest a track from Lake Superior
to Lake Michigan, but this very well could flip again. With
pronounced cyclonic flow have gone away from modeled QPF and have
introduced a general chance pops for showers all areas from Monday
night through Wednesday. Persistent cloud cover and nil temperature
advections will limit the daily heating response to the 60s
certainly through midweek.
MARINE...
Southeast winds increasing to 10 to 20 knots today as high pressure
exits East. The strongest winds will focus over the northern half of
Lake Huron. Winds will increase further Tonight as the pressure
gradient strengthens in advance of an approaching cold front. Expect
wind gusts topping out around 30 knots over the open waters of Lake
Huron. Wind gusts over nearshore waters look to be reaching around
25 knots. This cold front will bring showers to the area late
Tonight into Monday morning. In its wake, strong southwest flow with
gusts approaching gale force over central Lake Huron tomorrow and
tomorrow evening. Strong southwest winds will persist on Tuesday, if
not increase slightly more, as much colder air filters into the
Central Great Lakes.
HYDROLOGY...
Low pressure lifting into Northwest Ontario Today will swing a cold
front through Lower Michigan Monday morning. Showers are likely late
Tonight into Monday, with rainfall totals of a quarter to half an
inch. The progressive nature of the front and lack of heavy rain
producing thunderstorms will be a limiting factor, thus no flooding
is expected.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory from 10 PM this evening to 10 PM EDT Tuesday
FOR LHZ421-422-441>443.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
UPDATE.......RBP
AVIATION.....SF
DISCUSSION...CB
MARINE.......SF
HYDROLOGY....SF
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Grand Forks ND
1018 AM CDT Sun Sep 25 2016
.UPDATE...
Issued at 1016 AM CDT Sun Sep 25 2016
Looking at latest HRRR 975-950 mb wind fields and observations
feel pretty good chance that several areas of eastern ND will see
winds into the advisory range into the afternoon as upper low and
sfc low depart. Rolla wind gusts to 39 kts and Harvey as well
sustained 26 kts. Mixed layer supports potential for 45 kt gusts
today as well. Highest winds west of the RRV over higher terrain
but did push advisory into the RRV counties HRRR shows 45 kts over
GFK-Cavalier region mid to late aftn at 925 mb.
&&
.SHORT TERM...(Today and tonight)
Issued at 342 AM CDT Sun Sep 25 2016
The first challenge for today will be timing the final wave of
precipitation swinging around the back side of an upper low progged
to pass through the region. Short term/hi-res models are doing a
decent job capturing the current precipitation picture although
maybe a bit overdone in intensity. They are in good agreement with
precipitation moving into the Devils Lake basin around 10z and
slowly lifting north and east throughout the day. Therefore,
continued with the highest PoPs across the northern third of the
forecast area with decreasing chances further south.
Additionally, surface low pressure centered across southern Manitoba
will pull a weak cold front across the area today. Winds will switch
around to the northwest this morning/early afternoon as the surface
low moves off to the east. With high pressure then building into the
High Plains, a fairly tight pressure gradient will set up across the
area. Model soundings depict decent mixing throughout the afternoon
with 925 mb winds approaching 40 kts across the Devils Lake basin.
The majority of guidance continues to keep surface winds just below
advisory criteria so will forgo any headlines and let the day shift
reassess if observations start picking up earlier/higher than
forecast.
The breezy northwesterly flow will keep high temperatures quite a
bit cooler than Saturday with readings generally in the upper 50s
and low 60s.
.LONG TERM...(Monday through Saturday)
Issued at 342 AM CDT Sun Sep 25 2016
Monday through Tuesday night...As the upper low pulls away from
the area Sunday night, surface high pressure will develop across
the central CONUS with the main ridge axis expected to slowly move
across the area. Some lingering precipitation chances will persist
through early Monday across the far east before dry conditions
return and last through midweek. Plenty of sunshine will allow
high temperatures to gradually warm back to above normal values in
the upper 60s and low 70s. Winds should stay up enough under
mostly clear skies to keep low temperatures in the 40s, except
for Monday night which will see the lightest winds and
temperatures possibly dropping into the upper 30s.
Wednesday through Saturday...Upper level pattern is mildly
progressive through the period. Long wave ridge over the northern
Rockies will shift to the Great Lakes/southeast Canada by the end
of the period. Long wave trough over the eastern Pacific will
shift to the west coast.
The ECMWF was farther north and a little slower than the GFS. Both
the ECMWF and the GFS were trending slower over the last couple
model runs. Will blend the models. No significant weather system
expected through the period. Perhaps a short wave may move through
by next Sun.
Little change to high temperatures for Wed-Sat from yesterdays
forecast package.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 636 AM CDT Sun Sep 25 2016
MVFR/IFR ceilings and rain showers were around the periphery of the
forecast area (including KDVL and KBJI) with VFR conditions
sandwiched in between. These showers and associated ceilings with
gradually move from west to east throughout the period and affect
all sites at some point throughout the day.
Additionally, a cold front was situated just west of the Red River
Valley at 12z. Winds behind this feature (KDVL) have already
switched to the northwest with frontal passage expected at KGFK/KFAR
by 17z and KTVF/KBJI by 19z. A tight pressure gradient across
eastern North Dakota will bring winds of 20-25 kts/gusts to 35 kts
to KDVL and 15-20 kts/gusts to 30 kts to KFAR and KGFK while
slightly less east of the valley. Gusts will subside this evening
with sustained northwest winds of 10-15 kts continuing.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Wind Advisory until 7 PM CDT this evening for NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...Wind Advisory until 7 PM CDT this evening for MNZ001>004-007-029.
&&
$$
UPDATE...Riddle
SHORT TERM...Lee
LONG TERM...Lee/Hoppes
AVIATION...Lee
Area Forecast Discussion
National Weather Service Wilmington NC
946 AM EDT Sun Sep 25 2016
.SYNOPSIS...
A cold front will stall across South Carolina tonight before
returning north Monday. A stronger cold front will move across
the Carolinas Wednesday or Thursday. Behind this next front,
drier and cooler weather will arrive on northerly winds.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM Sunday...The cold front slipped through Wilmington
before sunrise but is decelerating as it pushes farther
southwestward. Northeasterly winds both ahead and behind the front
are making it tough to find the exact frontal location, but it
appears at 9 AM to run from Bennettsville and Dillon to Whiteville
and Southport. Overnight radiational cooling out ahead of the
front produced widespread fog, some quite dense, which is slowly
burning off across coastal South Carolina up through Marion into
Lumberton. Post-frontal low stratus has built into the Maxton-
Lumberton-Elizabethtown area but has remained north of
Wilmington.
With the front almost stalling during peak diurnal heating this
afternoon, look for scattered showers and thunderstorms to develop
near or behind the front. That`s not normally how fronts work in
this part of the country, but in this case the front is bringing
in deeper moisture from the Atlantic, making the best precip
chances behind the front. SBCAPE rises to 500-1000 J/kg and
convective capping falls to 0-10 J/kg. The latest several HRRR
runs aren`t all that impressed with shower chances this afternoon,
but I am not going to remove the 20-30 PoPs in the forecast. Cell
motion should be very slow from north to south.
Highs today should range from the upper 80s in the Pee Dee Region
(a 90-degree reading is even possible west of Florence) down to
the lower 80s on the NC beaches. The 06z NAM looks to have a
better synoptic handle on the frontal position and temperatures
than the GFS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...High pressure across New England will drift
offshore and this will allow the cold front to push back N of the
area during the day with surface winds turning onshore and
eventually to the SE Mon afternoon and eve. A subtle mid-level
shortwave will sneak up the coast late in the day Mon and Mon night.
A vigorous trough carving out across middle America is expected to
drive a cold front into and eventually through the eastern Carolinas
Tue night or Wed. Moisture will increase steadily during Tue and Tue
eve and then begin to drop off sharply with frontal passage
overnight, lastly along the coast Wed. Will show convection through
the period, but include the highest probability Tue afternoon and
night.
Highs will be about normal, lower 80s. Lows will be in the upper 60s
to lower 70s Mon night and then cooling in the wake of the cold
front to mid and upper 60s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 300 AM Sunday...Deep upper low will evolve across the Great
Lakes and then sink slowly SE through late week before ejecting into
Canada during the wknd. This will drive a cold front across the
Carolinas on Wednesday, but its overall progression is a low
confidence forecast due to model uncertainties into the evolution of
the aforementioned upper low. ECM is deeper and stronger with this
upper low, cutting it off entirely from the mean flow into next
wknd. The CMC is the fast solution with short cutoff followed by
rapid progression into the westerlies by late week. The GFS is a
decent compromise, although its ensembles show a very large spread
by D6. The biggest difference to the sensible weather from these
solutions revolves around precip potential, as temperatures will
likely be seasonable or slightly below regardless of which outcome
is correct.
Will favor the GFS attm which is supported by WPC, which
suggests the front will push offshore as the upper low begins to
move NE Thursday, with cool high pressure building down the coast
thereafter. Temperatures Wed/Thu will likely be around seasonable
norms or slightly above, but clouds and showers will be likely as
the front drifts towards, and then off, the SE coast. As the high
builds south late week and into Saturday, temps will cool to below
normal with mins potentially dropping to 60 or below, especially
inland, by the end of the period. If the ECM solution ends up being
correct, temperatures will still follow this trend, but both Friday
and Saturday could also feature periods of showers instead of the
drier forecast currently being shown.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 12Z...A cold front is passing through our northern CWA at this
time. Predominately northeast flow and MVFR conditions are expected
with brief IFR ceilings possible early on. There will probably be a
shower or two around, however they will be very weak as things
should remain quite stable with low CAPE expected. The front will
stall over our southern counties with light northeast flow overnight.
EXTENDED OUTLOOK...Chance for SHRA/TSRA each day through Wed.
Otherwise expect VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 945 AM Sunday...A cold front has pushed as far south as Cape
Fear this morning, and should crawl southwestward along the South
Carolina coast this afternoon. Northeasterly winds are in place
both ahead of and behind the front, making wind speed and air
pressure the best determining factors for locating the actual
front. Northeast winds should increase to a solid 15 knots with
gusts to 20 knots today, strongest in the Cape Fear vicinity. Seas
already as high as 3.5 to 4 feet north of Cape Fear should build
to 4-5 feet near and north of Cape Fear this afternoon, 3-4 feet
along the SC coast later this afternoon. Isolated showers or
t-storms could develop this afternoon in the Cape Fear to Myrtle
Beach vicinity, but most should remain inland.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...High pressure across New England will move
offshore and this will allow winds to shift from NE and ENE Mon
morning to E Mon afternoon and to SE Mon night. As a cold front
approaches the waters, SE winds Tue will become S and SW Tue
night. If the front does not slow down, winds may shift to the N
as early as the wee hours of Wed morning. The highest winds this
period will be Mon and Mon eve, up to 10 to 15 kt. Seas of 3 to 4
ft Mon and Mon night will subside to 2 to 3 ft Tue and Tue night.
LONG TERM/WEDNESDAY THROUGH THURSDAY/...
As of 300 AM Sunday...Some uncertainty exists in the extended with
respect to the timing of a cold front moving across the waters, but
attm it appears the front will stall over the waters Wednesday and
then shift well offshore during Thursday. This leaves a period of
highly variable winds on Wednesday with speeds of 5-10 kts, before
the front moves away Thursday followed by N to NE winds of 10-15
kts. Seas Wed and most of Thu will be 2-3 ft with residual 11-12 sec
swell remaining in the spectrum combined with low-amplitude wind
waves. Late in the period a northerly 4-5 sec wave will amplify, and
seas may build towards 3-4 ft late Thursday.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...DL
Area Forecast Discussion
National Weather Service Lincoln IL
1043 AM CDT SUN SEP 25 2016
.UPDATE...
Issued at 1040 AM CDT Sun Sep 25 2016
Update the forecast about an hour ago to remove the patchy fog
wording this morning. Also updated to lower pops over western CWA
this morning as much of area still mostly sunny and dry at 1030
am. HRRR model appears to be too quick develop convection over
central and western CWA late this morning and slowed this down by
a few hours. Otherwise one more warm and rather humid summerlike
day expected over central and southeast IL, with highs mostly in
the 80s, ranging from lower 80s over far nw CWA by Galesburg, to
near 90F far southeast CWA by Lawrenceville. Late morning surface
map shows a cold front over central IA and western MO while a
prefrontal trof was pushing east near the MS river. Aloft an upper
level ridge was over the OH/TN river valleys. Patchy fog lifted
during mid morning leaving mostly sunny skies across CWA.
Temperatures warmed up into the upper 70s and lower 80s while
dewpoints ranged from 65-72F with southerly winds 5-15 mph.
Models continue to push cold front east into the IL river valley
late this afternoon, and through central and eastern IL during
this evening. Models agree with scattered convection developing
across much of CWA during the afternoon and continuing this
evening especially east of the IL river. SPC day1 outlook has a
marginal risk of severe storms for 5% risk of damaging wind gusts
this afternoon until sunset/7 pm along and east of a Peoria to
Springfield line and north of I-70. CAPES increase to 1-2k J/kg
east of the IL river during this afternoon into mid evening and
highest over southeast IL where some models have CAPES peaking a
bit above 2k J/kg. The 0-6km bulk shear is weak over central and
southeast IL today, less then 30 kts east of the IL river this
afternoon and only increase above 30 kts behind the front nw CWA
late this afternoon.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 322 AM CDT Sun Sep 25 2016
CWA is now caught right in between the surface ridge to the east and
the cold front approaching from the west. Short-term model trend has
to slow the onset of precip into the CWA. Based on radar trends and
surface analysis, looks like precip will not arrive until this
morning; so, will have just slight chance of precip over the western
part of the CWA this morning and then increase pops to chance
northwest of the Illinois river before noon. Precip will spread east
through the CWA during the afternoon and into and then continuing
into the evening hours. Precip will gradually come to an end, from
west to east, behind the front after midnight. POPs will be in the
chance category ahead and behind the front, with likely along the
front as it moves east through the CWA. Precip type should be
showers and storms, mainly in the afternoon and evening, but
isolated thunderstorms will continue into the overnight hours
tonight.
Temps will once again be very warm across parts of the CWA, mainly
looking at the mid to upper 80s east of the Illinois river and
toward the IN border. Overnight lows will be cooler than the last
several days, with mid to upper 50s common, except in the southeast
parts of the CWA where lower 60s is likely.
.LONG TERM...(Monday through Saturday)
ISSUED AT 322 AM CDT Sun Sep 25 2016
Main focus for the longer range period will be the evolution of the
current upper low spinning over North Dakota. Models remain in good
agreement in this evolving into a fairly strong upper low over Lake
Superior by midday Monday, with the low only slowly weakening with
time as it wobbles across much of the Midwest. The latter week still
shows some discrepancies with the track of this low. The ECMWF
drifts it back north from the Tennessee Valley and it still is
present over northern Ohio by late Sunday, while the GFS lifts it
into New England on Friday. The former scenario would suggest some
late week showers as the associated surface low drifts north out of
Kentucky, while the latter scenario pretty much keeps us high and
dry aside for a few potential lake-effect showers over the far
northeast CWA on Thursday. With the uncertainty and what likely
would be spotty coverage at best, will continue to keep the forecast
dry for the time being.
A gradual moderation of the air mass should result in temperatures
climbing a degree or two each day this week, but the overall dry
conditions should result in a nice diurnal swing each day. Lows in
the 40s are likely Monday and Tuesday nights, and perhaps
Wednesday night as well if the ECMWF pans out.
The deepening of the low will result in rather breezy conditions
Monday and Tuesday afternoons, with some wind gusts of 25-30 mph
across the northern CWA.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 558 AM CDT Sun Sep 25 2016
MVFR conditions should prevail at all TAF sites next 24hrs, except
for some light fog around 2-4sm will be present this morning.
Based on dewpt spreads and what`s occurring right now, believe fog
will only last 1-2hrs. Satellite shows some scattered clouds
around 5kft, but the cold front approaching will keep these
scattered clouds and mid/high clouds around some of the western
TAF sites this morning. The cold front, still sitting across
central IA is forecast to reach the TAF sites this afternoon,
which is when the showers and isolated thunderstorms should reach
the TAF sites. Showers and storms have dissipated out west, but
expecting them to refire near the front as it moves into the area.
Precip will begin at the TAF sites later this afternoon and
continue into the early evening hours. Early evening will see area
still in cyclonic flow so isolated showers appear to still be
possible. Have a 20pct for showers at all sites. The after
midnight, clouds will scatter out. Winds will be southeast through
most of the day, and then become northwest...this evening.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Auten
LONG TERM...Geelhart
AVIATION...Auten
Area Forecast Discussion
National Weather Service Indianapolis IN
1038 AM EDT SUN SEP 25 2016
.UPDATE...
Aviation section updated
&&
.SYNOPSIS...
Issued at 304 AM EDT Sun Sep 25 2016
A cold front will move through the area tonight into early Monday
bringing showers and a few thunderstorms to the area. An upper low
could bring a few showers to northern areas mid week. Dry conditions
will then prevail. After one more warm day today, cooler and more
seasonable readings will continue into next weekend.
&&
.NEAR TERM.../This afternoon/
Issued at 1026 AM EDT Sun Sep 25 2016
Vorticity lobe currently located near the Mississippi river is expected
to drift east during the day. This feature may spark off some convection
over the west central and northwest zones by mid to late afternoon. Will
extend the PoPs for later this afternoon into some of the west central
zones as well to cover this feature.
Previous discussion follows.
A cold front will approach the area today. Until later in the day,
high pressure should remain in control with just an increase in
clouds.
Some models bring in rain before 00Z to the western forecast area
ahead of the front. The Hi Res Rapid Refresh has convection into the
area by 19Z. This seems overdone given what little forcing will be
available before the front arrives.
However, the GFS and Canadian bring in rain before 00Z. Although
less weight is given to the GFS since it typically overdoes QPF
coverage, the SREF also hints at this possibility. Given the above,
and after looking at neighboring office`s input, have decided to add
some slight chance PoPs to the far northwest 21Z and beyond.
With some decent sunshine for at least the first half of the day,
feel that MOS is too cold. Went closer to a raw model blend of
temperatures.
&&
.SHORT TERM.../Tonight through Tuesday night/
Issued at 304 AM EDT Sun Sep 25 2016
Focus is on chances for rain. Models are close enough that a blend
was used.
The cold front will move through the area tonight. An upper jet will
provide additional forcing while 850mb winds over 30kt bring in
additional moisture. Decent frontogentical forcing will be around as
well. Thus went likely PoPs most areas at some point during the
night, with later timing in the east.
Current expected timing of the system keeps rain still likely over
the east 3/8 of the area or so during the early part of the morning.
However, dry air moves in rapidly, so that by 15Z most areas are dry
and by 18Z everywhere is. Instability on Monday looks quite low so
removed any thunder mention.
Dry conditions should then prevail through Tuesday high pressure
nosing in.
An upper low will begin to move south out of the Great Lakes late in
the period. Models differ on path and how far south the rain gets by
late Tuesday night. Forcing doesn`t look impressive, and given the
uncertainty, was only comfortable adding in slight chance PoPs in
the extreme northeast forecast area.
For temperatures, generally stayed close to the model blend. Given
the dry air that will be in place for much of the short term, there
should be some decent diurnal ranges. The blend captures this pretty
well.
&&
.LONG TERM /Wednesday through Saturday Night/...
Issued at 331 AM EDT Sun Sep 25 2016
The extended period could start out with a few rain showers across
the northern counties as a low pressure systems departs to the
east. After that, a large ridge of high pressure will build over
the region, resulting in dry conditions and more seasonable
temperatures through the end of the long term period.
Initialization is handling the pattern well, so no deviations
were needed.
&&
.AVIATION /Discussion for the 251500z IND TAF update/...
VFR conditions are expected to continue. Forecast soundings
suggest convective temperatures will be reached this afternoon
with some sct CU developing. HRRR once again appears a bit over
done...and will hold off on any afternoon precip as it suggests.
Otherwise...ongoing tafs in good shape.
/Discussion for the 25/1200Z TAF Issuance/...
Issued at 720 AM EDT Sun Sep 25 2016
VFR conditions are generally prevailing at most TAF sites with
little fog development at this time. The main focus of the TAF
period though will be showers and thunderstorms with approaching
cold front. Showers and isolated thunderstorms should start
impacting KLAF and KHUF by Mon 03Z, spreading eastward into KIND
and KBMG. The best chances for convection will be in the Mon
09-12Z time frame. Prevailing conditions will generally be at VFR
levels, but they could quickly deteriorate to MVFR or worse during
any storms. Meanwhile, winds will start out east/southeasterly and
gradually veer to the southwest through the course of the period.
Winds could be breezy at times at KIND tonight with sustained
speeds of 12 to 15 kts.
&&
.IND Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/JAS
SHORT TERM...50
LONG TERM....TDUD
AVIATION...TDUD/JP
Area Forecast Discussion
National Weather Service New Orleans LA
928 AM CDT SUN SEP 25 2016
.SOUNDING DISCUSSION...
Only subtle changes have occurred over the last couple days, but
the most notable is the mean mid level temperatures in the 700-500
mb layer have cooled to point this morning where the capping
inversion has been basically eliminated resulting in higher lapse
rates throughout most of the troposphere. Precipitable water is
near the seasonal climatology near 1.6". The steep near-surface
inversion eroded when the surface temperature reached 80F and the
elevated low level inversion will be eroded when the surface
temperature reaches about 85F. Sounding projected max temperature
is 92 with a mixing height/mixed layer reaching up to 7-9 kft at
peak heating. The convective temperature is rather high at 90F.
Winds in the lower levels up to 10 kft were mostly southeast to
south averaging 6-12 knots, then mostly varying from northeast to
northwest at light to moderate speeds above 10 kft with the peak
wind 32 knots around 40 kft.
12z balloon info: a successful flight ascending for 127 minutes
reaching a height of 21.4 miles above the ground bursting over
eastern Lake Pontchartrain only about 16 miles south-southwest of
the office.
TD
&&
.PREV DISCUSSION... /issued 415 AM CDT SUN SEP 25 2016/
SHORT TERM...
Upper level ridge that encompasses most of the southeastern United
States is beginning to compress and weaken as a trough is moving
northeast across the high plains. The weakening of the ridge will
allow for scattered convection to develop and become slightly more
widespread today. Surface analysis shows a weak inverted trough
developing over southern Mississippi and Alabama. This correlates
perfectly with the general location where the HRRR suggests
thunderstorms will initiate this afternoon. These storms should move
southwest into the CWA along the MS/LA border before dissipating as
they track across the Florida Parishes. The latest forecast pops
were adjusted to represent expected convection. Those rain chances
are slightly above the previous forecast and what neighboring
offices have. Highs will be about the same as yesterday in the lower
90s which is several degrees above normal.
LONG TERM...
The ridge overhead will continue to suppress Monday which will allow
the trough to the north to dig further south. Rain chances should
remain in the low end change category as the first significant
cold front since last spring approaches the region. A reduction in
500 mb heights will result in high temps struggling to reach 90.
The upper trough will slowly push east while spreading south over
the southeast conus through Thursday. Much cooler and drier air will
surge south across the CWA during those days. Expect fall like
temperatures with highs in the lower to mid 80s and lows in the
upper 50s to lower 60s. These conditions could stretch into the
weekend albeit some air mass modification.
Meffer
AVIATION...
Generally VFR conditions will prevail through Sunday morning. A few
hours of lower cigs and vsbys will be possible around sunrise and
TEMPO groups have been included for the KHUM and KMCB. A sct cu
field is expected between 3 and 4kft by late morning and isolated
convection in the afternoon but too isolated to mention in taf
forecast for now. 18
AVIATION...
General VFR conditions expected all terminals through Monday
morning. KHUM and KMCB may see some localized light fog formation in
areas prone to drainage aspects near daybreak, but should be limited
in extent and duration. Isolated showers and thunderstorms will
occur this afternoon but too isolated to mention in taf
forecast...so will handle within 6 hours. 18
MARINE...
Light winds and low seas in a flat pressure gradient are expected
through Monday. Frontal passage expected into the gulf waters Monday
night to bring a moderate increase in offshore flow as cooler and
drier air builds into the north gulf. The continental high will then
settle over the eastern CONUS and moderate slowly throughout the
week while winds veer to a more easterly flow by mid-week. A
secondary surge may push through the coastal waters on Thursday. 18
DECISION SUPPORT...
DSS code: Green.
Deployed: None.
Activation: None.
Activities: None.
Decision Support Services (DSS) Code Legend
Green = No weather impacts that require action.
Blue = Long-fused watch, warning, or advisory in effect or
high visibility event.
Yellow = Heightened impacts with short-fused watch, warning
or advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby
tropical events; HazMat or other large episodes.
Red = Full engagement for Moderate risk of severe and/or
direct tropical threats; Events of National Significance.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 93 71 91 67 / 30 20 30 20
BTR 92 72 91 69 / 20 20 30 20
ASD 92 73 91 71 / 30 20 30 20
MSY 92 75 90 75 / 20 20 30 20
GPT 91 75 90 72 / 30 20 30 20
PQL 91 73 89 72 / 30 10 30 20
&&
.LIX Watches/Warnings/Advisories...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1023 AM CDT SUN SEP 25 2016
.UPDATE...
Cold front is now plowing southward into the northern South Plains
as of 15Z...with gusty northerly winds in its wake. Winds have
occasionally flirted with low-end advisory levels around Friona
and Dimmitt, but think think they will be sustained mostly in the
20 to 30 mph range. Still, will highlight the gusty winds within a
nowcast and adjust accordingly if they do exceed expectation. As
the front is encountering the better moisture it has been
generated scattered showers which should continue to increase in
coverage through late morning and early afternoon. Instability is
rather weak but we could still see a little thunder mix in later
in the day too. We have boosted PoPs along and south of the front
through 18Z...but did begin trimming back PoPs from north to
south during the afternoon and evening hours as it now appears the
drier post-frontal air will tend to win out over the increasing
elevated and weakening lift associated with the upper level storm
system backing away well to our west. Before then, elevated PWATs
could still yield a few locally heavy downpours, though limited
instability and post-frontal dry air advection will tend to keep
amounts in check at any given location as best focus shifts
progressively southward with time. Aside from adjusting the PoPs,
did also change the prevailing weather mention to rain showers with
isolated thunder. Additionally, post-frontal winds were raised a
notch for much of the FA through the afternoon.
&&
.PREV DISCUSSION... /issued 704 AM CDT SUN SEP 25 2016/
AVIATION...
Low stratus ceilings will linger in vicinity of all three
terminals through late morning with deep surface moisture in
place ahead of a cold front currently moving south through the
Texas Panhandle and should be south of KLBB by early afternoon.
KCDS has reported CLR for past couple hours leading up to sunrise
but short term guidance and overall pattern suggest ceilings could
drop quickly into LIFR quickly which has been handled with a tempo
group through late morning. KLBB will likely remain IFR to LIFR
until the front approached with KPVW in mostly IFR/MVFR ahead of
the front. Behind the front winds will be gusty out of the
northeast this afternoon into the evening hours.
PREV DISCUSSION... /issued 529 AM CDT SUN SEP 25 2016/
SHORT TERM...
Light rain currently embedded within gravity waves over Lamb County
seen on local radar as of 430am will be short lived as a cold
front continues to slowly move south out of the Texas Panhandle
into the South Plains. The cold front is struggling to overtake
the very moist surface layer situated primarily east of the I27
corridor where dewpoints remain in the low 60s up into southern
Kansas. While across the southwest Texas Panhandle dew points have
dropped into the mid 30s near Bootleg.
Given the cooler and drier air on the eastern half of the cold front
is struggling to push south, 00z synoptic model run initialization
is less than ideal. HRRR has been trying to catch up and output
seems to be indicating a less dynamic passage east of the I27
corridor which is indicated in the observations. Current water vapor
imagery shows lift associated with the trough pushing through the
Baja of California moving north toward the Guadalupe Mountains but
that lift appears to shift farther east by later this afternoon and
may be enough to destabilize the mid levels over the Rolling Plains.
But farther west into the South Plains any overriding will be weak
or nullified by a weak shear axis from the Pecos area north toward
Lubbock which may leave us drier than expected. Regardless the
precip gradient will be sharp along our southern zones as we go
through the day.
Highs will be in the upper 60s on the Caprock to low 70s in the
Rolling Plains as cooler air moves in eventually behind the cold
front. Rain will linger across our southern counties later tonight
as lift associated with the retrograding low over Baja California
slowly pulls activity to the west and low temps bottom out in the
50s for most of us Monday morning, and into the 40s in our northwest
zones.
LONG TERM...
By Monday morning, we will be pinched between a storm system
across the western Great Lakes and another over Baja California
Sur. Guidance has shifted the low just about 60 miles further west
of the Gulf of California as opposed to the previous run (and
closest to that indicated to the ECM two days ago.) Baja Low
should drift into southern California by late Wednesday before
getting swept up in the westerly flow. All the while, ridging
builds into the Central Plains before flattening toward next
weekend when SWRLY flow returns as another system approaches
Vancouver Island.
Guidance suggests that most, if not all, significant precipitation
should be south of the area by 12Z Monday with mildly breezy NERLY
flow at the surface. Some showers, however, remain possible
during the day mainly across the southern half. All in all,
guidance tends to over-estimate the residuals, and will taper POPs
downward. The NAM tries to hold on to some POPs in our SW late
Monday into Tuesday though the signal and synoptic setup make
confidence in this scenario quite weak. In fact, given the
available hints in deterministic guidance, it will likely remain
dry for the remainder of the extended.
&&
.LUB Watches/Warnings/Advisories...
None.
&&
$$
23
Area Forecast Discussion
National Weather Service Columbia SC
556 PM EDT SUN SEP 25 2016
.SYNOPSIS...
An upper-level ridge will continue to build east across the region
tonight then move off the coast Monday. A cold front moving into
the area tonight will stall across the area Monday providing a
focus for scattered showers and thunderstorms. Another cold front
will cross the area Tuesday night into Wednesday. The air mass
behind this system will bring dry weather and more seasonable
temperatures for the latter half of the week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A high amplitude upper-level ridge over the Mississippi Valley will
continue to move slowly east overnight. Upper-level cut-off low
over the Gulf coast area. At the surface, weak high pressure
remains. Upper-level trough over New England with surface ridge
building south along the Atlantic Seaboard will drive the cold
front slowly southwest tonight. The air mass across the region
will be marginally unstable. Convergence along the front and
upper-level dynamics appear weak. Latest high-resolution models
suggest little in the way of convection. Have forecasted slight
chance pops. Overnight lows generally in the upper 60s to around
70 degrees.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
Easterly low-level flow Monday resulting in deeper moisture. A
stalled frontal boundary across the area will support scattered
showers and thunderstorms in a weakly to moderately unstable air
mass. Convection may focus near a sea breeze front in the east Monday.
Deep upper low along the US/Canadian border Monday is forecast to
move southeast into the Ohio River Valley by Wednesday. Thus will
push a cold front through our area late Tuesday into Wednesday.
We`re still seeing some timing differences with the 00Z ECMWF
holding the upper low and cold front farther west. The 12Z GFS AND
12Z NAM are more progressive moving the cold front to the coast by
the end of the day Wednesday. We have continued the chance for
convection ahead of the front Tuesday then diminishing from west
to east Wednesday as the cold front moves east of the Midlands.
Temperatures are expected to remain above normal ahead of the
front Monday and Tuesday, with highs in the mid to upper 80s and
lows in the mid 60s to lower 70s. Should see slightly cooler
temperatures Wednesday with highs in the low to mid 80s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Typical fall weather to spread across the region for the end of
the week with seasonable temperatures.
Dry and cooler air advecting into the region Thursday. Surface
high pressure and stable conditions spreading across the region
into next weekend. Deep upper trough crossing the eastern states.
Overnight lows expected to range from the 50s to lower 60s with
afternoon highs in the mid 70s to lower 80s.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
Weak convergence associated with a backdoor cold front moving
into the area will help support stratus and fog development
tonight. Most of the NAM and GFS MOS plus HRRR suggested mainly
IFR stratus. Followed the GFS LAMP for the timing. Continued upper
ridging should help keep moisture shallow. Nocturnal cooling
should limit instability. The shower and thunderstorm chance
overnight was too low to include in the terminal forecasts at
this time. The diffuse front will remain in the area though the
rest of the TAF period but some diurnal ceiling improvement
should occur. The GFS and NAM MOS were in good agreement with
generally VFR conditions developing during the day. Some increase
in moisture will occur in an easterly flow Monday. The moisture
and some convergence associated with the diffuse front in the area
plus heating should support scattered showers and thunderstorms
but still expect limited coverage with significant forcing
associated with the next approaching cold front west of the area
through the TAF period. Again, the shower and thunderstorm chance
was too low to include in the terminal forecasts at this time.
EXTENDED AVIATION OUTLOOK...A slow moving cold front will be in
the area through Wednesday. Widespread stratus and fog may occur
especially during and late night and early morning hours. There
will also be scattered showers and thunderstorms. Drying may occur
behind the front Thursday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
Area Forecast Discussion
National Weather Service Fort Worth TX
321 PM CDT SUN SEP 25 2016
.DISCUSSION...
As showers and thunderstorms continue across mainly the eastern
half of the region this afternoon, a cold front is racing towards
North Texas. The location of the actual front is muddled among
precipitation in NW Texas but the front is expected to enter our
northwest counties in just a few hours. It will continue to
steadily progress south and southeast tonight bringing cooler and
eventually drier weather to the region. But before we get to the
dry, pleasant weather expected this week, we have some challenging
rain chances/trends to discuss first.
An outflow boundary that has persisted since this morning is still
slowly moving east this afternoon. The outflow boundary stretches
pretty much along where moderate to heavy convection is occurring
to the east of Interstate 35/35E. The steering flow is from the
south which has resulted in training of storms along and near the
boundary for much of the day. This trend is expected to continue
into the evening hours as the boundary continues to push east. The
HRRR indicates weakening of this activity around sunset. Showers
and storms near this boundary have been very efficient rainfall
producers, and where training of cells has occurred, rainfall
totals of 2-4 inches in 1-2 hours have been reported. So far, no
significant flooding issues have been reported. Flash flood
guidance is high because of the dry period we have been in
recently, but minor flooding of low-lying areas, creeks, streams,
and streets/roads will continue to be a threat due to the higher
rainfall rates.
As the front moves through the region this evening and tonight,
expect an increase in rain across the region. The upper level
dynamic forcing is not very strong with an upper level low well
to our west and an upper level ridge to our east. With a
relatively cool and overworked environment in place across North
and Central Texas, and north winds already in place ahead of the
front, confidence is low in how much additional rain activity will
develop with the front. However, moisture content is still high
with dewpoints in the upper 60s and lower 70s, so at least some
additional rain is expected tonight. Hi-res guidance suggests some
robust cells may occur, potentially aided by a northward moving
shortwave currently near Sonora (south of San Angelo). For the
evening and overnight period, will continue with likely PoPs
across all but the area along the Red River and our far northeast
counties. Rainfall amounts may not be as high overnight as they
have been today, but it does appear much of the area could at
least see light to moderate rain at some point. Additional
rainfall amounts up to 1 inch are possible overnight with isolated
higher amounts.
Rain chances on Monday are still questionable due to considerable
spread in the guidance, but we anticipate much of the region will
remain dry as the cold front pushes south. North and Central Texas
will be under weak ridging aloft between the upper level low over
Baja California and an upper level trough moving across the
Midwest. While surface dry air will start filtering into the
region, deeper layer dry air will be slower to arrive and some
elevated isolated showers or storms may develop. As the drier air
deepens across the region on Tuesday, it should bring a final end
to any precipitation. For Monday and Monday night, will carry low
chances for rain generally along and south of Interstate 20.
The remainder of the week looks dry and pleasant. Generally north
winds at the surface all the way south into the Gulf of Mexico
will severely limit moisture return through the week. An upper
level ridge will re-establish over the region but the drier air
will keep temperatures pleasant with highs in the 70s and 80s and
overnight lows in the 50s and 60s. Humidity values will also
remain low with the lack or moisture return.
JLDunn
&&
.AVIATION...
/ISSUED 1247 PM CDT SUN SEP 25 2016/
A very tricky TAF cycle continues today at all sites as the
pertinent mesoscale details are being handled poorly by recent
high-resolution model guidance. Needless to say, this is a fairly
low confidence forecast, even in the short term.
For the Metroplex: recent radar trends reveal a general reduction
in the most robust cells, with a transition towards more showery
precipitation. It`s possible we pick up some filtered sunshine
through the afternoon hours, and given how moist the environment
is, it won`t take much to spark off additional thunderstorms and
will continue to prevail -SHRA VCTS after 20Z. While winds have
gone light northwesterly behind an outflow boundary, the actual
cold front will not arrive until about 02Z tonight, at which point
wind speeds will increase and most of our thunder chances will
diminish. MVFR cigs will likely accompany the front and will
linger into the morning hours on Monday. A gradual improvement to
low-end VFR cigs should occur through the mid-morning hours on
Monday.
For Waco: outflow has pushed east of the TAF site, taking most of
the shower and thunder activity with it. With breaks in the
clouds, additional scattered thunderstorm development will be
possible through the afternoon hours. Tonight, the cold front
looks to push through around 05-06Z. MVFR and IFR cigs will
develop as the front passes.
Carlaw
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 65 75 60 79 58 / 60 20 10 10 0
Waco 66 76 59 79 56 / 70 20 20 10 5
Paris 65 77 56 79 55 / 40 10 10 5 0
Denton 63 74 53 77 52 / 60 10 10 5 0
McKinney 64 76 55 78 53 / 60 10 10 10 0
Dallas 66 75 61 81 59 / 60 20 20 10 0
Terrell 66 77 59 79 55 / 60 20 20 10 0
Corsicana 67 78 59 80 58 / 70 20 20 10 0
Temple 66 75 59 77 57 / 70 40 20 10 5
Mineral Wells 61 71 53 76 52 / 70 20 20 10 0
&&
.FWD Watches/Warnings/Advisories...
None.
&&
$$
90/82
Area Forecast Discussion
National Weather Service Wilmington NC
658 PM EDT Sun Sep 25 2016
.SYNOPSIS...
A cold front will stall across South Carolina tonight before
returning north Monday. A stronger cold front will move across the
Carolinas late in the week though its timing is highly uncertain.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 645 PM Sunday...Have tweaked pops a bit to reflect isolated
shower activity, now mainly over Horry and Columbus Counties.
Activity is moving slowly SW with a few embedded lightning strikes
being indicated. High-res guidance has activity fading by around
midnight. Previous discussion follows:
This morning`s cold front has nearly stopped moving southward and
is stalled over eastern South Carolina in the vicinity of
Georgetown, Florence, and Hartsville. With northeast winds on both
sides of the boundary it`s a bit nebulous exactly where the front
is. Dense low clouds never burned off across northern and central
North Carolina, but fortunately the post- frontal airmass never
became that well established here before the sun rose this
morning. Northeasterly low-level flow should push these lower
clouds southwestward after sunset.
So far we`ve seen virtually nothing on radar. The HRRR appears to
have been right all along and I`ve trimmed PoPs back to just a small
20 percent chance through this evening from west of Wilmington to
around Conway and Marion.
Weak cool advection should be felt most strongly across coastal SE
North Carolina tonight as the high over New England points its ridge
axis down in that direction. Broken low clouds will help to hold
heat in overnight and my forecast lows are close to the warmer NAM
MOS guidance, except at ILM where a slug of dry air after midnight
associated with the ridge may allow better radiational cooling to
occur. Lows mainly upper 60s with some lower 70s on the beaches.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
As of 300 PM Sunday...The 500 mb ridge over the Southeastern U.S.
will get beaten down over the next two days as an upper level trough
begins to dig southward across the Great Lakes. The surface high
will move off the New England coast Monday; return flow behind this
high should lift today`s cold front back to the north again, with
the boundary moving back into Virginia by Monday evening. A weak low
in the northern Bahamas will get lifted northward by the same low
and mid-level flow. While this feature should remain 50-75 miles off
the coast as it moves northward Monday into Tuesday, its closest
approach late Monday night into Tuesday morning could enhance
rainfall potential, at least along the coast.
By Tuesday, attention will shift to a cold front entering the
western Carolinas, preceding the upper level trough over the Great
Lakes. This front should stall as the upper trough deepens and cuts
off. With a humid tropical airmass in place Tuesday ahead of this
stalled front, scattered showers and t-storms appear quite possible,
especially inland. Assuming there are no unresolved upper level
disturbances present, precipitation should diminish Tuesday evening
with the loss of daytime heating.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 3 PM Sunday...Interesting weather early in the period with a
very large trough on Wednesday turning into a major cutoff low well
into the weekend. Trouble is, models are not in agreement regarding
the longitude of the cutoff. As a result it is difficult to
determine whether we see a FROPA locally or spend most of the long
term in the warm sector of the deeply occluded surface low. Even
FROPA model solutions do not push the boundary very far offshore so
either way the weather appears to be unsettled. The main
ramifications of the aforementioned uncertainties then will likely
affect temperature/dewpoint forecast. The ECWMF has been seemingly
leading the way in figuring out how this system will evolve and it
has been showing the least progression. It now delays the front
until about Saturday morning and it is not indicative of any
significant airmass change. The GFS looks like it is trending in the
direction of the EC so the forecast will be hedged in that
direction.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 17Z...Favored a blend of the models for this period with
more confidence in the NAM and GFS then the ECMWF due to the
handling of the H5 low across the nrn portion of the country
during the next few days. Cold front south of KILM and KLBT at
this time and right near KCRE/KMYR/KFLO. Predominately northeast
flow and MVFR conditions are expected with mention of vcsh along
the coastal terminals but will leave out mention inland. HRRR a
bit overdone with the pcpn potential across the region but as
mentioned in the near term forecast best chances for pops are just
behind the front so that is enough reason for the vcsh. BUFKIT
seems to agree with this scenario as well with pcpn ending around
00z across the coastal terminals. Moderate confidence in MVFR due
to ceilings during the overnight period with improvement to vfr
after daybreak. Winds will stay up along the coast but I will
lower across KLBT and KFLO overnight.
EXTENDED OUTLOOK...Chance for SHRA/TSRA each day through Wed.
Otherwise expect VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 645 PM Sunday...Latest obs show E to NE winds of around 15
kts in the wake of the recent cold front, with seas of 3 to 4 ft.
This fits in well with the latest forecast, of which there is no
change. Previous discussion from this afternoon follows:
This morning`s cold front has made it only a short distance down
the South Carolina coast this afternoon. The boundary will settle
somewhere near the Santee River tonight where it should remain
stalled through Monday. A healthy northeast breeze around 15 knots
with gusts to 20 knots should continue most of the night as high
pressure builds south across New England. Seas 3-5 ft across the
NC waters and 3-4 feet across the SC waters consist of a mix of
11-second easterly swell from former Tropical Storm Karl and 4-5
second wind waves.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 PM Sunday...As high pressure moves off the New England
coast Monday and out to sea Tuesday, our synoptic wind direction
will veer from northeasterly Monday morning to southeasterly by
Monday night. Normally it would hold this direction, however it
appears that a weak area of low pressure in the Bahamas will move
north along the Gulf Stream Monday, approaching to within 50-75
miles of Cape Fear Tuesday. Circulation around this feature may turn
our winds back to the northeast for at least the first half of
Tuesday before the southeasterly winds redevelop Tuesday afternoon
or evening. Wind speeds should average 10-15 kt Monday, but lighter
through Tuesday and Tuesday night.
LONG TERM/WEDNESDAY THROUGH FRIDAY/...
As of 3 PM Sunday...Confidence is very low for the long term. A cold
front driven southward by a cutoff upper low is being handled very
poorly by various models. Solutions range from a somewhat clean
FROPA on Thursday to the front lingering to our west until Saturday
morning. Have trended the forecast towards the slower timing since
models do tend to be gravitating in that direction. While the
current wind direction forecast may be way off given the
uncertainties at least that is some confidence that both wind speeds
and seas will remain quite manageable for most mariners.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...TRA
LONG TERM...MBB
AVIATION...MAC
MARINE...REK/TRA/MBB
Area Forecast Discussion
National Weather Service Indianapolis IN
618 PM EDT SUN SEP 25 2016
.UPDATE...
The Near Term Section has been updated below.
&&
.SYNOPSIS...
Issued at 304 AM EDT Sun Sep 25 2016
A cold front will move through the area tonight into early Monday
bringing showers and a few thunderstorms to the area. An upper low
could bring a few showers to northern areas mid week. Dry conditions
will then prevail. After one more warm day today, cooler and more
seasonable readings will continue into next weekend.
&&
.NEAR TERM /Tonight/...
Issued at 618 PM EDT Sun Sep 25 2016
Moved pops about 25 miles or so further east over the next few hours
based on radar trends.
Previous discussion follows...
Issued at 220 PM EDT Sun Sep 25 2016
Vorticity lobe currently drifting through western Illinois may spark
off some convection later this afternoon and evening, especially
over the western zones.
Appears better precipitation threat will arrive later tonight as
model data suggest cold front will be moving into the northwestern
border zones around 260400Z. There appears to be decent upper
support aloft associated with this front, given a mid level jet max
around 70 kts, but most of the support lags behind the front. As a
result, think most of the precipitation will be near the front and
in the post frontal zone. Will go with the highest PoPs during the
late night hours tonight and into the pre dawn hours of Monday,
timed with the better upper support.
Low level thicknesses generally support the GFS MOS guidance lows
tonight.
&&
.SHORT TERM.../Tonight through Tuesday night/
Issued at 304 AM EDT Sun Sep 25 2016
Focus is on chances for rain. Models are close enough that a blend
was used.
The cold front will move through the area tonight. An upper jet will
provide additional forcing while 850mb winds over 30kt bring in
additional moisture. Decent frontogenetical forcing will be around as
well. Thus went likely PoPs most areas at some point during the
night, with later timing in the east.
Current expected timing of the system keeps rain still likely over
the east 3/8 of the area or so during the early part of the morning.
However, dry air moves in rapidly, so that by 15Z most areas are dry
and by 18Z everywhere is. Instability on Monday looks quite low so
removed any thunder mention.
Dry conditions should then prevail through Tuesday high pressure
nosing in.
An upper low will begin to move south out of the Great Lakes late in
the period. Models differ on path and how far south the rain gets by
late Tuesday night. Forcing doesn`t look impressive, and given the
uncertainty, was only comfortable adding in slight chance PoPs in
the extreme northeast forecast area.
For temperatures, generally stayed close to the model blend. Given
the dry air that will be in place for much of the short term, there
should be some decent diurnal ranges. The blend captures this pretty
well.
&&
.LONG TERM /Wednesday Night through Saturday/...
Issued at 242 PM EDT Sun Sep 25 2016
ECMWF showing some differences from superblend this period as the
ECMWF suggests that an upper low will settle across the Ohio
Valley through this period...pivoting several waves through the
area. GFS keeps this feature farther east...mainly over the middle
atlantic states. Thus confidence is low for now and have included
superblends low pops where it has been allowed. Confidence remains
low. However northwest continental flow does seem prevalent through
the period which should result in near normal tempertures.
&&
.AVIATION /Discussion for the 252100z TAFs/...
Issued at 430 PM EDT Sun Sep 25 2016
Bumped up timing of VCTS and added tempo -TSRA to KLAF from 22 to 0Z
based on movement of echoes currently in western Illinois and this
increasing confidence of current HRRR solution. For KIND just
updated current conditions as confidence of this early evening
convection affecting there is low. At this time have not changed
KHUF, but will closely monitor there for an early thunder addition
if radar trends in that direction.
Models suggest strong cold front arriving overnight as forecast
soundings and time heights become saturated. Thus expect a line of
shra/tsra to push across the state with MVFR CIGS and visibilities
possible after around 7z.
Strong Subsidence and dry air expected to arrive in the wake of
the cold front...improving all taf sites to VFR after 18Z Mon.
&&
.IND Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...JAS/MK
SHORT TERM...50
LONG TERM....PUMA
AVIATION...JP/CP
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
144 PM CDT SUN SEP 25 2016
.SHORT TERM...
136 PM CDT
Through Monday...
Warm and humid conditions are in place early this afternoon ahead of
an approaching cold front. Temperatures have warmed into the mid to
upper 80s with dewpoints in the upper 60s across the area
contributing to moderate instability. Modified sounding from ILX
indicates just over 1000 J/kg SBCAPE in place across portions of the
area which initialized well on latest RAP guidance. With minimal CIN
in place, cu field has become increasingly agitated across much of
central IL and far northwest IL with scattered showers and
thunderstorms developing across those areas. Hi-res convective
allowing models continue to show widely scattered to scattered
showers and thunderstorms shifting across the remainder of the
forecast area through the late afternoon and evening hours. Deep
layer shear will likely be a limiting factor for a more organized
severe thunderstorm threat. Values of 15-20kt are in place south of
I-80 though do increase to 25-30 kt as you head northwest corner of
the CWA. With steep low/mid level lapse rates, cannot rule out an
isolated pulse severe wind threat, but overall am not impressed with
the severe setup.
Cold front will sweep across the region this evening and tonight
with winds shifting to the west/northwest and remaining breezy
overnight. Guidance suggests some precip possible immediately behind
the front as the upper wave moves across the region, but soundings
show the low levels quickly drying out behind the front so not sure
it will amount to much.
Cooler and blustery conditions will be in place on Monday. Should
see plenty of sunshine in the dry airmass outside of some scattered
afternoon cold-air stratocu development. Cold airmass will promote
deep mixing with top-of-the-channel winds of 30-35kt resulting in
strong wind gusts at the surface, especially during the afternoon
hours. Expect widespread wind gusts of 30-35 mph during the
afternoon, and cannot rule out a few sporadic gusts pushing 40 mph.
Afternoon highs will only be in the mid to upper 60s.
Deubelbeiss
&&
.LONG TERM...
139 PM CDT
Monday night through Saturday...
Overall this period is on the drier side with seasonally cool
conditions with the best chance Tuesday night into Wednesday. The
deep upper low will only slowly move southward on Tuesday, though
it will get shoved with a bit more earnest later Tuesday and
Tuesday night. Therefore the day should start off as continued
cool and breezy with more sun then clouds, but late in the day
expect cloud cover to increase along with increased chances of
rain showers. These patterns tend to afternoon diurnal increases
in the chance of showers, but core of the cold temperatures aloft
will be moving through overnight into early Wednesday and
therefore would just suggest either clouds or more scattered
showers. As the low moves south a secondary surge of colder air
will move through which could make Wednesday the coolest day of
the week with some chance of showers, especially south of the lake
and across Northwest Indiana where the better chance of
instability showers along with some lake effect/enhancement
possible. There is also some hint of lake convergence later
Wednesday and Wednesday night which could lead to an uptick in
lake effect showers given a decent thermally driven instability
signal. Upper level heights will be increasing during this time
such that the equilbrium levels remain low enough to preclude any
thunder with any possible activity, but there could be some lake
effect continuing into early Thursday.
The general trend is a very slow moderation in the airmass back to
normal levels for late September, though there are some
significant model discrepancies regarding how quickly the low
exits the region. NCEP/GEM ensembles suggest that ridging will
slowly move in but the upper low will become blocked to some
degree. There is some spread in these members, and the EC would
bring continued showers Fri/Sat after the low initially pulls
away. but the farther western track of the EC is not favored at
this time as it is at the western envelope of guidance and even
west of its ensemble mean. Therefore the trend is for generally
dry conditions and a temps near climatological highs in the upper
60s to low 70s with a cool northeast wind into the weekend. Long
range models hint at another warm up beyond this period once the
low does kick out east but this could take a little time.
KMD
&&
.AVIATION...
For the 18Z TAFs...
A slow moving cold front will push across the region this evening
and tonight with showers and thunderstorms expected out ahead,
and strong winds behind. Mother nature starting to show her hand
early this afternoon with prefrontal showers developing from
central WI into far northern IL while the cumulus field is
starting to become more agitated across portions of central IL.
Hi-res convective allowing models have been fairly consistent
showing some scattered development mid-afternoon affecting the
terminals, though timing and coverage details have varied.
Additional convective development this afternoon could be very
near or over the terminals so will not have much time to further
hone in on timing details. Additional showers are possible with
the front this evening and possibly even some rain for a couple
hours behind the front, though drier air is eventually expected to
arrive behind the front.
Outside of the influence of precip, SSE winds late this
morning/early afternoon are expected to veer to the SSW by mid
afternoon with gusts to around 20 kt possible. Expect SW flow to
continue into the evening hours until the cold front sweeps
through with winds turning W/WNW behind the front. Even stronger
winds are expected tomorrow with mid to high 20 kt gusts possible
and may even tag 30 kt at times.
BMD
&&
.MARINE...
139 PM CDT
The first fall-like system will move across Lake Michigan tonight
resulting in a more active period across the lake to start the
week with higher winds and waves expected for several days. Low
pressure across central Canada will send a strong cold front
across Lake Michigan tonight. As the low sinks south toward Lake
Superior Monday, a high pressure ridge across the plains will
extend eastward across the Ohio River Valley. A seasonally strong
pressure gradient coupled with a warm lake will easily result in
westerly winds to 30 kt, and even some occasional gale force
winds, most notably Monday and Monday night. The low will only
slowly sink southward through the Great Lakes through midweek.
During this time winds will shift to more northwesterly but will
still remain in the 20-30 kt range through early Wednesday. The
wind field appears on the stronger side then that normally seen
for waterspout development, but several guidance sources suggest
that as the low nears and begins to pull away midweek that there
could be better convergence of the wind field across southern Lake
Michigan and support waterspouts. Depending on how quick the low
pulls out, an extended period of northerly winds may continue
elevated waves on the south half of the lake. High pressure will
bring a calmer period late week into the weekend.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Marquette MI
409 PM EDT SUN SEP 25 2016
.SHORT TERM...(This evening through Monday)
Issued at 409 PM EDT SUN SEP 25 2016
12Z raobs/latest wv imagery and RAP analysis show hi amplitude
pattern dominating NAmerica featuring deep upr trofs in the plains
and over the Cndn Maritimes arnd an upr rdg over the Great Lks/NW
Ontario. Potent shrtwv lifting nnewd thru the Plains trof is moving
toward Lk Winnipeg with 12hr h5 hgt falls aprchg 100m. Mstr surge in
the warm conveyor belt ribbon ahead of this feature under h85 sw
winds up to 40 kts/sharp pres gradient btwn attendant sfc lo pres in
nrn Manitoba/attendant cold fnt in the plains and sfc hi pres over
Quebec and New England advected 12Z pwats up to about 1.75 inches
over INL/MPX, 250-300 pct of normal. Showers on the ern flank of
this mstr ribbon are impacting mainly the central zns despite drier,
stable airmass shown on the 12Z GRB/APX raobs closer to the sharp
upr rdg axis that has kept the far ern cwa dry. Dry slotting
following the warm conveyor belt has resulted in a band of partial
clrg fm the MN Arrowhead into far nw WI. Looking farther to the w,
there is a pronounced cool pool and plenty of lo clds over the nrn
Plains spreading into MN under the upr trof/behind cold fnt, with
12Z h85/7 temps at Bismarck, ND, down to 4/-2C. The 12Z h85/925 nw
winds at Bismarck were about 50/45 kts and are aiding the strong
caa.
There are a number of fcst concerns in the short term, mainly pops
and winds that wl accompany the passage of the warm conveyor belt
mstr ribbon/sfc cold fropa.
Late this aftn/tngt...Axis of deep mstr/deep lyr qvector cnvgc under
the warm conveyor belt are fcst to shift w-e acrs the cwa thru this
evng, exiting the far e arnd 06Z. Since the showers unstream have
become less wdsprd, wl fcst no hier than likely pops. Mucapes no
more than about 250 j/kg under this warm conveyor belt wl support no
more than isold TS. Dry slotting in the wake of the warm conveyor
belt/cold fropa wl diminish the pops as early as this evng over the
w and may actually bring some brief clrg as obsvd this aftn right
behind cold fropa over MN. But then more backwash mstr/lo clds wl
surge into the area later tngt in the strengthening cyc w flow
behind the fropa. The most wdsprd lo clds and some showers wl impact
mainly the hier terrain of the w with arrival of sharper trof
axis/some upslope wind component. h85 temps falling to about 4C wl
add a lk effect component to the pcpn as well.
Mon...Sharp, slowly veering wsw to wnw cyc flow under slow moving
trof axis/area of deep lyr qvector cnvgc associated with closed lo
driftng thru Ontario just n of Lk Sup wl bring nmrs/even wdsprd lk
enhanced showers to mainly the nw half of the cwa. Although no sharp
pres rise center that would aid an isallobaric component to the wind
is fcst to follow the trof axis, h925 winds up to 40 kts under the
thermal troffing wl support wind gusts aprchg advy criteria at
exposed locations over the Keweenaw Peninsula by later in the aftn.
As the winds veer a bit more toward the w over the ern cwa, waves
are fcst to build sufficiently to cause a hi swim risk in the
beaches of Alger County late in the day. Fortunately, the wx
conditions wl likely discourage swimmers.
.LONG TERM...(Monday night through Sunday)
Issued at 246 PM EDT SUN SEP 25 2016
Focus in the long term continues to be on a low pressure system that
will be occluding over or just N of far northern Lake Superior Mon
evening. The low will linger in the vicinity of the far northern
lake until Tue morning when it will start a slow move to eastern
Upper MI by 00Z Wed. The system moves S of the area Tue night, with
SFC and upper ridging moving in from the NW on Wed.
Main significant impacts will be strong winds near/over Lake
Superior and resulting high waves. Certainly will be seeing plenty
of rain, but not a worrying amount.
Models agree quite well with the track/strength/timing, but some run
to run variability still exists, so the wind forecast will continue
to need fine-tuning. Expect the strongest winds (at least in the
long term) on Monday evening with WNW gusts to 45mph along Lake
Superior over the western U.P. and over much of the Keweenaw. NW-N
winds will gust 35-40mph near Lake Superior for the rest of Mon
night through Tue. Winds will diminish Tue night into Wed.
Winds/waves will lead to dangerous swimming conditions on Lake
Superior, as well as beach erosion (especially along eastern Lake
Superior). No need for a beach hazards statement as temperatures
will be below criteria and it will be rainy.
Lake enhancement will occur as 850mb Temps will be 1-4C from Mon
into early Wed, which when combined with deep cyclonic flow and
upslope forcing will lead to lots of rain near Lake Superior and
more scattered showers well inland. Winds will favor WNW flow area
Mon night, NW-N flow areas Tue, N-NE flow areas Tue night, then
diminishing chances in north central Upper MI Wed morning as NE flow
remains while ridging increases. Should easily see over an inch of
rain Mon night and Tue over the higher terrain of the NW and a
quarter to half inch elsewhere near Lake Superior...under a quarter
inch south central. Tue night into Wed should add another quarter
inch or less of QPF...highest over the higher terrain of the north
central.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 145 PM EDT SUN SEP 25 2016
Gusty sse winds wl advect a good deal of mstr into Upr MI ahead of
an aprchg cold fnt. The combination of this llvl mstr and showers wl
result in period of MVFR/hi end IFR conditions at the TAF sites. The
arrival of some drying following the cold fropa with a wshft to the
wsw wl then bring at least a brief improvement to VFR w-e this evng
into the overngt before more llvl mstr arrives and causes cigs to
drop into the MVFR category, earliest at IWD/CMX. Winds shifting to
the w wl become gusty over the wrn TAF sites on Mon mrng, especially
at the more exposed CMX location.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 409 PM EDT SUN SEP 25 2016
Sse winds that will gale force over portions of the e half of the
lake will diminish w to e this evening/tonight along with an
approaching cold front/weakening gradient. Maintained going gale
warning into late tonight for the far e section of the lake as
terrain enhancement may focus stronger winds in this area. A more
widespread w gale to 35-40 kts will develop over Lake Superior on
Mon under the tightening pres gradient/increasing instability behind
a lo pres trof passage. Opted to upgrade the gale watch to a warning
for this event. With the slow approach of hi pres, these strong
winds will diminish later Tue into Wed. This hi pres will then bring
light winds to end the week.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Warning from 8 PM this evening to 4 AM EDT Monday for
LSZ267.
Gale Warning from 5 PM Monday to 5 AM EDT Tuesday for LSZ265-266.
Gale Warning from 11 AM EDT /10 AM CDT/ Monday to 8 AM EDT /7 AM
CDT/ Tuesday for LSZ162-240>242-263.
Gale Warning from 2 PM Monday to 5 AM EDT Tuesday for LSZ264.
Lake Michigan...
None.
&&
$$
SHORT TERM...KC
LONG TERM...Titus
AVIATION...KC
MARINE...KC