Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/09/16
Area Forecast Discussion
National Weather Service Albany NY
1048 PM EDT THU SEP 8 2016
.SYNOPSIS...
A cold front approaching from the Great Lakes will trigger
showers tonight, before tapering off later tonight. Weak high
pressure will bring generally fair and warm conditions for Friday,
but with lower humidity levels. A warm front approaching from the
southwest will bring showers and thunderstorms for Saturday,
followed by a cold front with additional showers and thunderstorms
Saturday night. Cooler and much less humid conditions will follow
for Sunday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
One area of showers has exited the CWA. A second area is
approaching. No lightning observed in this second cluster of
storms. Surface instability is nil. Elevated instability lingers
overnight. But with no lightning currently observed and weak
forcing have removed mention of thunderstorms overnight.
Air mass is extremely moist. Evening ALY sounding had a PWAT of
2.43 inches. (Not suprisingly a look at the water vapor loop shows
a plume of moisture extending back from NY/New England to the
tropical Pacific.) This is 3.8 standard deviations above normal.
Despite extreme PWATS, rainfall totals have not been extreme.
Storms have moved along at a fairly good clip. Any one storm can
produce a quick shot of rain, but not expecting any flooding
concerns, other than perhaps some ponding of water on roads, with
the storms overnight.
Have leaned on the HRRR for timing of next batch of precipitation
across the CWA. Have used coverage wording in the forecast and
allowed for up to "Numerous" showers tracking activity across the
CWA.
It will be warm and very humid overnight, with low temperatures
mainly ranging from the mid 60s to lower 70s, with some valley
areas possibly holding in the mid 70s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Friday, weak high pressure should build in from the west. Although
the sfc cold front should shift south and east of the region in
the morning, models suggest that the cold front within the
H850-H700 layer will slowly move east/southeast in the afternoon.
It appears that low level stability should preclude any additional
showers/thunderstorms for the afternoon, but will have to watch
trends. High temperatures should reach the mid/upper 80s in most
valleys, with upper 70s to lower 80s across higher terrain. Some
areas of the mid Hudson Valley could reach or surpass 90.
Friday night, high pressure will shift across and eventually east
of the region. The warm front aloft should being lifting back
northward late at night. This may lead to some shower/thunderstorm
development toward daybreak across southern areas, if not further
north. Will include slight chc POPS toward daybreak. Otherwise, it
will be cooler and less humid compared to tonight, with lows
mainly in the upper 50s to mid/upper 60s.
Saturday-Saturday night, a warm front should lift north across the
region during the day, followed by a strong cold front at night.
Showers and embedded thunderstorms should accompany the warm
front. There is some uncertainty as to how fast this front and
associated convection lifts through the region, with the NAM
suggesting a much slower passage, prolonging several rounds of
showers/thunderstorms through the day, while the GFS suggests a
more rapid passage and more limited convective potential. For now,
have taken blend of MAV/MET MOS for temperatures, with mainly mid
70s to lower 80s, although should the NAM prove correct,
temperatures may side on the lower end of the range. There may be
a break in the activity before a line of showers/thunderstorms
preceding/accompanying the cold front pass through Saturday night.
Models are trending stronger and slightly more negatively tilted
with the upper level shortwave associated with this feature, which
may delay the showers/storms until late Saturday night. Lows will
mainly be in the 60s.
Sunday, the cold front should move through around or just before
daybreak, but with the main upper level trough lagging, will keep
chances of showers through the morning, especially across western
New England. Expect clearing for the afternoon. It will be quite
breezy Sunday afternoon, with some gusts possibly exceeding 30 mph
at times, especially adjacent to the Mohawk River into the Capital
Region and Berkshires. Highs should be in the 70s, except 60s
across higher elevations.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Except for Wednesday...this will be a rain-free period with low
relative humidity and very few clouds. Strong high pressure crests
over the Northeast and Mid-atlantic Sunday night through Monday...
giving way to low pressure which will track southeast across the
northern Great Lakes to northern New York through Tuesday night...
providing our only chance for wet weather. Behind it and its
associated frontal boundaries...an even larger and stronger dome of
high pressure will works its way eastward...cresting over the lower
Great Lakes region Wednesday night.
High temperatures on Monday will be in the upper 60s to upper 70s
range. Warming just ahead of the Great Lakes system will bring high
readings up to the around 70 to lower 80s range...along with
increased humidity. After that we finally begin to notice a cooling
trend...with highs by Thursday ranging from only around 60 degrees
in the high peaks of the Adirondacks and Greens...to the lower 70s
down the Hudson Valley. Humidities Thursday will also be quite low.
Overnight lows...which will be from the mid and upper 40s to the
mid and upper 50s Sunday and Monday nights...will hold up in the mid
50s to lower 60s range Tuesday night. Wednesday night will be
markedly cooler with lows ranging from around 40 degrees in northern
Hamilton County to the lower or mid 50s in the mid Hudson Valley.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Convection has worked through ALB and GFL, now approaching PSF.
Convection approaching PSF has not exhibited much in the way
lightning. Still some instability to work with at PSF. Thus have a
2 hour period from 00-02Z for IFR TSRA. At POU have precipitation
timed in there around 02Z. Did not include any TSRA for POU.
752 pm Update...Well that last long. GFL has gone IFR in BR. Have
amended forecast to allow for IFR BR through the night. For the
remainder of the night, still some showers upstream of the
terminals, so have covered with VCSH. This is FG season, and all
terminals have/will see some precip. Given expectation of plenty
clouds around tonight, have not included any IFR BR/FG at any
sites.
Outlook...
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact. Breezy Chance of SHRA...TSRA.
Saturday Night: Moderate Operational Impact. Likely SHRA...TSRA.
Sunday: Low Operational Impact. Breezy Slight Chance of SHRA.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
A cold front approaching from the Great Lakes will trigger
showers and thunderstorms this evening, before tapering off later
tonight. Weak high pressure will bring generally fair and warm
conditions for Friday, but with lower humidity levels. A warm
front approaching from the southwest will bring showers and
thunderstorms for Saturday, followed by a cold front with
additional showers and thunderstorms Saturday night. Cooler and
much less humid conditions will follow for Sunday.
&&
.HYDROLOGY...
An approaching cold front will bring scattered to numerous showers
and thunderstorms tonight. Locally heavy downpours will be
possible, and could lead to ponding of water in poor
drainage/urban areas. However, this rainfall should only have
negligible effects on area rivers.
Additional showers and thunderstorms are expected Saturday into
Saturday night.
Other than the showers and thunderstorms with the frontal
systems, no widespread soaking rainfall is expected through at
least early next week.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...KL/OKeefe
NEAR TERM...KL/OKeefe
SHORT TERM...KL
LONG TERM...ELH
AVIATION...OKeefe
FIRE WEATHER...KL/11
HYDROLOGY...KL/11
Area Forecast Discussion
National Weather Service La Crosse WI
708 PM CDT THU SEP 8 2016
.SHORT TERM...(This evening through Friday night)
Issued at 340 PM CDT Thu Sep 8 2016
Some wonderful drying today with glorious sunshine. About time!
The first 30 hours of this forecast are the most interesting. The
frontal zone across southern IA/NEB is not too far away and holds
the tropical moisture pool. The latest 88D winds at 1500 m showing
directions shifting to S-SW to begin the moisture return northward
in the last hour over SD and ern NEB. Water vapor imagery is
showing a big time fall-season trough upstream with mucho energy.
The first wave is over KFSD at this time with some shower
activity. This may bring a few sprinkles to the northwest area
this evening but is coming into a dry environment. The second
shortwave is over northwest WY (arrives later tonight), and the
big daddy of them all is over British Columbia (arrives Friday).
Heights are already falling across the Plains and the southerly
flow is beginning to work on the frontal zone. Good agreement on
about 750 J/Kg of MUCAPE moving in from the southwest for
elevated parcels overnight. Mid-level lapse rates are still
favorable as well, in the 7C/km range or slightly above, before model
convection dilution. The 850 mb moisture push is really
impressive with a strong gradient from -10C to 13C, and the 13C
paralleling the Miss river by sunrise. This would saturate the
bottom of the steep lapse rate layer quickly and initiate parcels
in weak-moderate convergence in swrn MN. Maybe a slight push
aloft from the WY shortwave trough. So, it seems the environment
is conducive for shower and thunderstorm development later
tonight. Very good consensus in the CAMS over the past 8 hours
too on this solution. Timing is roughly 09Z Rochester-Charles
City and the Miss River by sunrise. This area should continue to
shift east in the morning. Have increased storm chances late
tonight into the morning. Severe storm chances are marginal but
there - 800 J/Kg with those steep lapse rates and elevated bulk
shear of 30 kts (depending on storm depth, it could be higher)
favoring a marginal severe hail threat. The shear above 5 km is
awesome, but the storms may not be deep enough to `feel` it.
The big daddy potential vorticity anomaly, with a tropopause fold
in the 08.19Z RAP down to 750mb, deepens into the Plains Friday.
QG forcing is deep and strong Friday, with cold frontal passage in
the afternoon and evening. The question is how much can we
destabilize for storms and a severe weather. Bulk shear in the
linear hodograph varies in the lowest 4 km among the models, with
great shear above that. Dynamic lift is excellent. Storm type
would seem to favor splitting supercells or line forcing quickly
congealing any afternoon storms into bowing segments. MLCAPE still
recovers in the models to near 1500 J/Kg - somewhat surprising.
But concerned it will be cloudy after a morning of rain, and
recovery will suffer. Thus, have taken a strong to severe
approach in the messaging. The severe storm threat and area may
not be known until Friday mornings rain can be solved, but it
appears near and south of I-90 may be the best dynamics and CAPE
union area.
.LONG TERM...(Saturday through Thursday)
Issued at 340 PM CDT Thu Sep 8 2016
Saturday will be a drying day overall with cold advection and
breezy 15-25 mph winds, possibly gusting to 30 mph west of the
Miss river. There is a small shower chance early, and have slowed
the clearing slightly thinking there would be some
cumulus/stratocumulus development until very dry air moves in
later.
Sunday through Thursday...Looks to be a no weather impact period
with mainly below normal temperatures and dry conditions...or
small rain chances /Monday and Tuesday/. The Great Lakes remain
under a zonal to northwest flow pattern in the large scale.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 708 PM CDT Thu Sep 8 2016
Showers and thunderstorms are expected at the TAF sites early
Friday morning with at least one more round of showers and storms
during the day on Friday. Periods of IFR conditions are possible
in any heavier downpours. Also, some of the storms may become
severe with large hail. Showers and thunderstorms will push east
of the TAF sites by late Friday evening.
&&
.HYDROLOGY...
Issued at 340 PM CDT Thu Sep 8 2016
HEAVY RAINFALL IS NOT IN THE FORECAST HOWEVER SOME SITES MAY
RECEIVE UP TO AN INCH FRIDAY. THE UPPER IOWA...PINE...AND KICKAPOO
RIVERS ARE EXPECTED TO CONTINUE THE DOWNWARD TREND.
&&
.ARX Watches/Warnings/Advisories...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...WETENKAMP
HYDROLOGY...BAUMGARDT
Area Forecast Discussion
National Weather Service Cleveland OH
940 PM EDT THU SEP 8 2016
.SYNOPSIS...
A cold front over the area will sink south tonight then lift back
north into the region as a warm front by Friday night. A second and
much stronger cold front will push through late on Saturday. High
pressure will build in on Sunday.
&&
.NEAR TERM /THROUGH FRIDAY/...
The weak slow moving cold front is allowing the band of shra and
some tsra to only slowly get pushed south. Latest HRRR and RAP
models show convective activity continuing to affect mainly the
south half of the cwa the rest of the night...although there is a
general weakening of intensity that occurs. Based on dynamics and
convective processes...the above model guidance seems reasonable so
forecast for rest of the night will show this.
The thermal profile does not show a notable change overnight so not
expecting a significant cool down. The subtle drop in dewpoints and
northerly winds could push lows into the upper 60s in the far nw and
for inland nw pa but even these numbers area well above normal lows.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
An area of surface high pressure will build over the area behind
the cold front for Friday. This will allow for minimal cloud cover
especially in the early part of the day. The H850 temps drop a few
degrees by tomorrow morning, but are expected to warm back up to
around 19C by later in the afternoon. This combined with plenty of
sunshine should easily support temperatures in the mid to even
upper 80s, with the exception of the east where heights will be
slower to rise. Have gone several degrees above guidance for
these reasons.
Rain chances will increase late Friday as the frontal zone begins
to shift back northward in response to an approaching upper level
trough. The shear will increase in advance of as a surface low
begins to deepen over IL. The shear is sufficient to support
organized convection which is likely to develop along and behind
the advancing warm front late Friday night/early Saturday
morning. The convection behind the warm front will become more
scattered early Saturday, but we expect another round of organized
convection later in the day as a cold front moves in from the
west. With an upper level jet, deepening low moving by the area,
and increased shear there will be the potential for strong to
severe storm development along this frontal boundary. Rain chances
should come to an end Saturday night as the and upper trough move
east of the area. Heavy downpours will be likely with any showers
given extreme amounts of available moisture, though confidence is
low that there will be any organized heavy rain over any
particular location. A widespread inch of rainfall appears likely
with some spots potentially picking up a couple of inches.
Looking at a notable drop in thicknesses for Sunday as surface
high pressure builds in. There is some concern of lake enhanced
development in the east, but for now it looks like the amount of
dry air and subsidence moving in should be able to overcome that.
Highs will be in the lower to mid 70s under partly cloudy skies.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
The surface high will slide east of the area on Monday and Monday
should remain pleasant. Tuesday should be warmer and the forecast
temps will be warmer than guidance given the high heights aloft and
the propensity for quick warm-ups this season.
The models are getting closer with the timing of the next front on
Wednesday. The GFS remains the fastest and the CMC remains
slower with the ECMWF in between. Will split the difference. When
push comes to shove, we will probably need "likely" pops with the
front but since the the frontal passage straddles late Tuesday night
and Wednesday the forecast will end up with "chance" for each period.
High pressure will build south by Wednesday night and Thursday. We
may well end up with some lake effect clouds but did not want to go
"cloudy" given the anticyclonic flow behind the front. Temperatures
will drop below normal by Thursday.
&&
.AVIATION /00Z Friday THROUGH Tuesday/...
Showers with a few thunderstorms are training along a boundary
extending from KDAY-KMFD-KCAK-KYNG. Expect showers will linger along
this boundary through much of the evening and may continue at
CAK/YNG into early Friday morning. Clouds will linger at these sites
and along the lakeshore for much of the night, eventually dropping
to low MVFR or IFR as the slow moving cold front arrives late.
Visibilities will also drop to MVFR at most sites and could locally
drop to IFR at locations that received more rain this evening.
TOL/FDY will clear out late this evening which will allow
visibilities to drop more quickly with the potential for fog. More
likely scenario is for a low stratus to develop, likely below 500
feet with visibilities holding closer to 1 mile from 08-13Z.
Visibilities are expected to return to VFR by 14Z Fri with
ceilings clearing from north to south behind the front from late
morning through the afternoon. Winds will generally be light
southwesterly tonight shifting to north or northwest on Friday.
The exception will be near showers or thunderstorms where erratic
winds are possible with gusts to 20 knots.
OUTLOOK...Non-VFR likely in showers and thunderstorms Friday night
and Saturday.
&&
.MARINE...
Waves have dropped into the 2 to 4 foot range for the nearshore
waters east of Geneva-On-The-Lake so have cancelled the Small
Craft Advisory and High Risk of Rip Currents. Winds and waves will
continue to gradually decrease overnight but conditions will
remain a little choppy on the east end of Lake Erie.
Winds will lighten up considerably for Friday as high pressure
crosses Lake Erie. Winds will veer northwest and then come around
from the south Friday night ahead of the next front.
A stronger cold front will cross Lake Erie on Saturday and it will
not be a good day for boating. Southwest winds will increase and
shift to west and then northwest late. Winds will be gusty and there
will likely be thunderstorms.
A brisk northwest to north wind behind the front will require a
small craft advisory which may be needed into Sunday morning east of
Cleveland. Winds should calm down quickly from west to east Sunday
into Sunday evening as high pressure begins to spread in.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Jamison
NEAR TERM...Adams/Jamison
SHORT TERM...Jamison
LONG TERM...Kosarik
AVIATION...KEC
MARINE...KEC/Kosarik
Area Forecast Discussion
National Weather Service State College PA
1203 AM EDT FRI SEP 9 2016
.SYNOPSIS...
The strong ridge aloft over the MS/OH valleys will keep us much
warmer than normal through the end of the week. Muggy air will
stick around until a strong cold front passes this weekend. After
a day or two of seasonable temperatures Sunday and Monday another
warm- up will occur.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Earlier line of strong thunderstorms has evolved into an east-west
line of mainly showers. HRRR keeps showers translating east across
the area into the early morning hours, but it never really dries
out overnight as we remain within the ribbon of high PWATS
basically embedded in the quasi-zonal flow aloft.
It will remain muggy...unseasonably so...with dewpoints in the
lower 70s across much of central and southern areas. Much more
like July to early August than early to mid September.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
With baroclinic zone bisecting the commonwealth on Friday...there
will be much more cloud cover than today. Upper ridge will
actually rebound slightly on Friday afternoon as digging trof
approaching the Ohio valley late in the day. This will allow the
south and southeast to bake once again with apparent temps once
again in the mid to upper 90s. Deep layer moisture will be farther
south. Boundary layer forcing will be non existent...but with flat
ridging at best...there will still be slight to chc pops in the
afternoon across the southern half in conjunction with anomalous
PW. Still...Friday should be the least active of today through
Saturday overall.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Mid-scale trof digging over the northern Plains is forecast to
swing through the Northeast and northern Mid Atlantic regions near
the start of the long term period and into the weekend, with the
subtropical ridge rebuilding early next week. This trof and
associated surface cold front should support the hiest chances of
pcpn during the period.
Behind the front, a return to dry weather is in store. It will
be noticeably cooler on Monday, but then turn warm again Tuesday
and Wednesday as the upper ridge rebuilds northward.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
BFD has IFR cigs which should continue into tomorrow morning and
should finally lift between 14Z to 16Z.
Showers continue to stream through central PA. This will keep MVFR
at most TAF sites between 06Z to 12Z with lingering low cigs
through 15Z.
Outlook...
Fri...AM low cigs possible w mtns. Local restrictions in sct TSRA
south.
Sat...Isold PM tsra impacts possible, mainly w mtns.
Sun...AM log cigs possible w mtns.
Mon-Tue...No sig wx.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...DeVoir/La Corte
NEAR TERM...La Corte
SHORT TERM...DeVoir
LONG TERM...Gartner
AVIATION...Ceru/RXR
Area Forecast Discussion
National Weather Service Grand Forks ND
935 PM CDT THU SEP 8 2016
.UPDATE...
Issued at 935 PM CDT Thu Sep 8 2016
Most of the earlier showers have weakened or moved off to the
east now. However, there are some more showers between Bismarck
and Minot that will track up toward Grand Forks by late evening
if they hold together. If like the previous batch, they will
amount to just a few hundredths of rain here and there.
&&
.SHORT TERM...(This evening through Friday)
Issued at 305 PM CDT Thu Sep 8 2016
Forecast challenge will be timing of light showers, sky, and
associated impacts on temps tonight and tomorrow. Overall, prefer
the HRRR this evening transitioning into a model blend for
overnight and tomorrow periods.
An area of light rain showers and possibly an isolated
thunderstorm over central ND will advect into Devils Lake area
over the next couple of hours and spread west to east across the
CWA. Mid level moisture so do not anticipate much in the way of
rainfall accumulation, generally a couple of hundredths total.
Expect to see a break in activity near morning before a cold front
drops into the northern tier from srn Canada, with more light
rain, very scattered in nature, spreading north to south across
the area tomorrow. Cool temperatures generally in the mid to
upper 60s are expected as a much cooler air mass sinks into ND.
.LONG TERM...(Friday night through Thursday)
Issued at 305 PM CDT Thu Sep 8 2016
Lingering shower chances into Friday evening. High pressure will
move in late Friday and into Saturday with clearing skies.
Temperatures behind the front will drop a few degrees below normal.
Winds turning south-southwest on Sunday and increasing ahead of next
cold front due to arrive Sunday night. Warm and dry ahead of the
front with temps in the mid 70s to low 80s. Chance of showers
behind the front Sunday night into Monday as cooler air moves in.
Shower chances continue into Monday evening before high pressure
builds into western North Dakota Mon night and bring clearing skies
overnight to eastern ND and the RRV. Temperatures coldest in the far
northwest with some upper 30s possible. Lingering clouds and and/or
late clearing in the Red River valley into Minnesota will keep lows
in the low-mid 40s. A dry stretch for a change Wed-Fri as high
pressure moves slowly east and temperatures moderate back to near
normal. Northern stream jet stream remains in central Canada while
another piece of the jet stream digs over the central Rockies. This
puts our area in a drier airmass and at least for the time being
away from moisture.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 655 PM CDT Thu Sep 8 2016
Should see light winds and mid level clouds overnight. Then the
biggest thing on Friday will be a cold frontal passage. This will
bring a switch to west winds in the morning (ND side), then
northwest winds and a few showers by late morning into the
afternoon. The northwest winds could get a little gusty at times,
but mainly at KDVL/KFAR/KGFK.
&&
.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&
$$
UPDATE...Godon
SHORT TERM...Speicher
LONG TERM...Riddle
AVIATION...Godon
Area Forecast Discussion
National Weather Service Lincoln IL
907 PM CDT THU SEP 8 2016
.UPDATE...
Issued at 907 PM CDT Thu Sep 8 2016
Precip has diminished considerably in the southeast and a dry
forecast looks good for the rest of the evening. More precip is
out west and should be arriving late tonight. Light winds, mostly
clear skies and lots of left over low level moisture should lead
to fog development overnight. Current forecast appears to have a
good handle on the overnight situation, but will still be making
adjustments to pop/wx forecast in the grids. An update will be
sent this evening, even though changes may be minor.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 257 PM CDT Thu Sep 8 2016
Area of showers and a few thunderstorms has become more widely
scattered south of I-72 at mid afternoon. More widespread convection
is east of IL over central IN and sw of CWA over southwest IL and
into central/southeast MO. An outflow boundary has pushed just
southeast of I-70 at mid afternoon and this is the area where
thunderstorms with heavier rains are located east of Terre Haute and
sw of Effingham. Meanwhile northern CWA has dried out and getting
some breaks in the low clouds. HRRR and RAP models show convection
slowly shifting southeast across southeast IL into this evening and
then most areas fairly dry overnight with some fog develop
especially from I-70 north. Have trended forecast drier tonight over
central and northern CWA and added patchy fog overnight into early
Fri morning. Muggy lows overnight in the upper 60s and lower 70s.
Chances of showers and thunderstorms to increase from sw to ne
across CWA during Friday morning as frontal boundary gets tugged
back northward as a warm front in response to surface low pressure
lifting northeast into west central/nw IL by sunset Friday. SPC day2
has marginal risk of severe storms across CWA with slight risk of
severe sw of a Canton to Springfield line later Friday afternoon and
Friday evening. Moderate to heavy rains will be possible again on
Friday and especially Friday night as cold front moves into central
IL with precipitable water values as high as 2-2.4 inches southeast
of IL river and in record territory for Sep. Held off on issuing a
flash flood watch since heaviest rains appears to occur Friday
night. Flash Flood guidance values range from 1.5-2.4 per hour, 1.8-
3.4/3 hr and 2.3-3.9/6 hr and highest over southeast IL which has
not seen as much rainfall so far. Highs Fri range from near 80F
northern CWA to mid 80s southeast of I-70. Humid again with
dewpoints in the low to mid 70s.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 257 PM CDT Thu Sep 8 2016
The forecast period will start out wet as a vigorous short wave and
associated cold front push into the area. Anomalously high
Precipitable Water values near 2" as the system pushes into the area
will still support heavy rainfall with showers/storms, but shear and
instability parameters are not especially conducive to severe
storms. The cold front is progged to push east of the forecast area
by midday Saturday, with the post frontal airmass/weather pattern
supporting quiet and cooler than normal conditions through the
remainder of the weekend.
Neutral/zonal upper-level flow will develop across the eastern U.S.
behind the Friday night/Saturday morning front, lingering into early
next week. Meanwhile, deeper troffing and an upper low will develop
across the western states. The next weather feature of note/concern
locally will be a northern stream wave that will pass mainly to our
north Tuesday into Wednesday. This system should push a cold front
through the area as it passes by, providing our next risk of
showers/storms. The exact timing of this front is still in question
due to the fact that it will become more parallel to the local upper
flow, which will also be much weaker than to the north.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 652 PM CDT Thu Sep 8 2016
VFR conditions will start each site this forecast period. But with
lots of low level moisture around and light winds, and skies
remaining high based mostly cloudy; think fog will become a factor
overnight. For now, will bring VIS and Cigs lower gradually and
then drop them further during the overnight hours, into the LIFR
category, blo 1kft cig and vis around 2sm. Lower clouds in the AM
will also keep some of the lower clouds around during the early
morning hours. Conditions will gradually improve during the
morning in the MVFR category. Then precip associated with a
boundary will move up from the southwest and should move into the
southwest parts of the CWA beginning late morning and then
continuing to the northeast through afternoon. So will have shra
and VCTS at all sites. Winds will be light and variable tonight
and then become southeast to south through the day.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...07
LONG TERM...Bak
AVIATION...Auten
Area Forecast Discussion
National Weather Service Indianapolis IN
1035 PM EDT THU SEP 8 2016
.UPDATE...
Aviation sections updated
&&
.SYNOPSIS...
Issued at 300 PM EDT THU SEP 8 2016
A cold front over eastern Wisconsin and northwest Illinois will move
to central Indiana late tonight and become stationary. Low pressure
tracking across the upper midwest will pull this front back to the north
late Friday and move a trailing cold front southeast across our region
Saturday. It will be dry and cooler early next week as high pressure
behind this front builds eastward.
In the long term another cold front will bring a chance of thunderstorms
towards the middle of next week.
&&
.NEAR TERM /Rest of Tonight and Friday/...
Issued at 924 PM EDT Thu Sep 8 2016
UPDATE...
Showers and thunderstorms have become confined to the south
and eastern sections of the forecast area with dry conditions
elsewhere. The persistent rainfall is currently creating flash
flood issues across the south central and southeastern counties.
However, there is little development currently upstream, so patchy
fog could develop later, especially over northern counties.
Current temps across the area are generally in the low to mid 70s
and are expected to bottom out in the upper 60s/low 70s. Updated
grids have been sent.
PREVIOUS DISCUSSION...
Numerous showers and a few thunderstorms were occurring over the northwest
half of central Indiana...northern Indiana...central Illinois and Missouri.
This area will continue to spread slowly southeast across our region this
afternoon. The rapid refresh model indicates storms will become more
scattered this evening and may temporarily end over northern sections
late tonight. Will go with likely POPS mainly south tonight and then
decrease them some overnight. SREF indicates possibility of patchy fog
some areas...mainly north late tonight.
On Friday...a frontal system over central Indiana will move back to the north
as a southerly flow increases across the area. Will go with likely POPS
south all of Friday and north by Friday afternoon. Went close to a MOS
blend on temperatures with lows tonight in the upper 60s to lower 70s and
highs Friday from around 80 north to middle 80s south.
&&
.SHORT TERM /Friday night through Sunday/...
Issued at 300 PM EDT THU SEP 8 2016
Models indicate a 40 to 45 knot 850 MB jet will push into our region
Friday night and this combined with persuadable water of around 2.5 inches
will produce numerous showers and thunderstorms. HPC has us under a
slight risk of excessive rainfall. Could see locally heavy rainfall.
But since this is in the 3rd period and flash flood guidance is over
3 inches will not issue any headlines at this time.
Models indicate a cold front will move across Indiana Saturday and will
continue high chance POPS for then. Saturday night and Sunday will be
dry and cooler as the cold front moves on to the east and high pressure
behind the cold front builds our way by late Sunday.
Stayed close to a MOS blend on temperatures with lows around 70 Friday night
and the lower to middle 50s Saturday night. Highs will be in the upper 70s
to around 80 Saturday and the middle 70s Sunday.
&&
.LONG TERM /Sunday Night Through Thursday/...
Issued at 232 PM EDT Thu Sep 8 2016
Models are close enough that the SuperBlend initialization was
accepted for most items.
An upper trough will push a cold front through the area mid week,
bringing chances for rain to the area during that time. Lower
confidence for PoPs on Tuesday, with latest model runs holding off
until Tuesday night. However, left SuperBlend alone for the most
part, just delaying the chances until afternoon.
Temperatures will return to below normal behind the front later next
week.
&&
.AVIATION /Discussion for the 090300Z IND TAF/...
Ongoing TAF remains in good shape as VFR Conditions will continue
the next couple of hours. Convection to the southeast of
Indianapolis is expected to continue to drift away from the TAF
site. MVFR to IFR conditions are expected to develop during max
cooling hours overnight as dew point depressions are expected to
be less than 1F. Thus will continue to trend toward MVFR/IFR
conditions overnight.
Previous discussion below
/Discussion for the 090000z tafs/...
Issued at 749 PM EDT Thu Sep 8 2016
VFR conditions are expected the first few hours of the TAF period.
MVFR/IFR conditions are expected during the max cooling hours. As
heating returns on Friday...a return to VFR conditions are
expected.
Ongoing showers across Central Indiana are expected to drift south
of most of the taf sites...and only continue to impact BMG
through the overnight hours. HRRR continues to stream precip
across southern Indiana including Bloomington through the
overnight hours. Thus have continued the precip mention there.
Elsewhere...partial clearing...recent rains...light winds and low
dew point depressions will lead to MVFR to IFR fog and CIGS after
09Z.
Forecast soundings dry out late tonight and early on
Friday...which should lead to VFR conditions after morning fog
burns off. Another Short wave is expected to arrive late in the
afternoon on Friday. Forecast soundings become saturated by late
afternoon and have introduced prevailing VFR rain. Instability
looks limited...but a rumble of thunder cannot be ruled out.
&&
.IND Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/TDUD
SHORT TERM...JH
LONG TERM...50
AVIATION...JP
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
958 PM EDT Thu Sep 8 2016
.UPDATE...
Issued at 958 PM EDT THU SEP 8 2016
Clear skies continue to prevail across the forecast area as
upstream convection nudges closer to northeast Kentucky. Looks
like the upstream convection will stay north of the area for the
next several hours, given recent IR imagery trends. So have
nudged pops towards the HRRR solution which keeps the rain out of
the area until about 12Z. Also freshened up the sky cover and
hourly temps. Sent updates to NDFD and web servers.
UPDATE Issued at 650 PM EDT THU SEP 8 2016
Shower activity is still well to our west this evening per recent
radar trends so backed off on the timing of precipitation. Also
reduced sky cover in the near term since diurnal cu is currently
dissipating. Still expect the cloud cover and precip chances to
increase as the weak front approaches the area but it looks like
it will take a bit longer to reach the area than originally
forecast. The latest high-res convective models don`t have any
precipitation entering the forecast area until close to 12Z. As
such, trended the grids in that direction. Also freshened up the
hourly temps to reflect most recent obs and sent updates to NDFD
and web servers.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 354 PM EDT THU SEP 8 2016
Surface high pressure continues to sit just southeast of the region,
bringing return SW flow and warm moist air into the region. This has
led to temperatures rising to around 90 degrees across much of
eastern KY this afternoon, in addition to high humidity values.
Meanwhile, a cold front is currently in place to our NW,
stretching from Nebraska, part of the mid Mississippi Valley, and
northward through the Upper Great Lakes region. This frontal
boundary will continue to slowly propagate southeast toward the
state through the rest of the evening/overnight while becoming
more west to east oriented. It should finally push south of the
Ohio River and into the northern portion of the state during the
day Friday (tomorrow), but will lose any further southward
momentum, and will linger along the Ohio River instead throughout
the day. It will then finally lift northeast as a warm front by
Friday night as the next system starts to move toward the region.
As for sensible weather, the warm moist airmass in place, in
addition to the incoming frontal boundary, has created lift and
instability across the region. This has led to shower and
thunderstorm development, with increased coverage as you near the
frontal boundary. While eastern KY remains dry so far this
afternoon(thanks mainly to our location nearer to the high pressure
center), portions of north central KY have seen some small showers,
and it will be possible for some of these showers and maybe even a
thunderstorm to make it into the far northern portion of the CWA by
early evening. Pops then continue to increase across our northern
counties throughout the overnight. Expect scattered pops to remain
in place here through Friday as the frontal boundary slows and
becomes more stationary. Though without any farther push southward,
much of the southern half of the CWA should remain dry tonight
though Friday as well.
When the cold front finally pushes back NE as a warm front Friday
night, pops will quickly come to an end across much of the CWA,
though some lingering low end pops will be possible in the far
northern counties. We will cool slightly tomorrow with the presence
of the cold front and more cloud cover, but only by a few degrees
(in the mid and upper 80s). Lows both tonight and tomorrow night
will be in the mid and upper 60s. S to SW winds will also remain in
place throughout the entire short term period.
.LONG TERM...(Saturday through Thursday)
Issued at 244 PM EDT THU SEP 8 2016
The period will start with strong ridging off the east coast with
a sharp shortwave trough moving east across the mid/upper
Mississippi river valley. This mid level trough will push a
surface cold front east into the Ohio river valley late Saturday
and Saturday night producing our best chance for showers through
the entire forecast period. Modest forcing will collide with
decent moisture to support good chances for rain. Thus, will bump
rain chances up into the likely (60 percent) category. Front
should move through fairly quickly, so rainfall totals should stay
under a quarter of an inch for most areas. Instability is rather
limited with the front, but LI`s do dip to about -2 late Saturday,
supporting a marginal thunder threat. Regardless, will keep
thunder chances limited to a slight chance. With the departure of
the front, high pressure will bring dry weather from Sunday
through Tuesday night. In addition, a sizable cool down is in
store for the late weekend period with highs on Sunday back into
the 70s, and lows Sunday night well into the 50s. A few upper 40s
may be possible. As the high slowly shifts east early next week,
temperatures will start to climb, but should stay in the mid 80s
tops for much of next week. Lows may still dip into the 50s each
night as humidity never quite fully returns. Another shortwave
trough will dive southeast across the great lakes late Wednesday,
pushing another cold front south into Kentucky. As models stand
now, most of the forcing will stay northeast of the area, but the
presence of the boundary could spark a few showers or storms
Wednesday afternoon/evening. This boundary will likely stall to
our south by Thursday, allowing dry weather to return along with
slightly cooler conditions.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 745 PM EDT THU SEP 8 2016
As a weak cold front approaches the region tonight, clouds will
increase and eventually lower to MVFR closer to dawn. A chance
for showers and thunderstorms will also make their way into
northeast KY overnight, but will mainly affect areas north of the
Mountain Parkway including the KSYM TAF site towards dawn.
Scattered rain chances and MVFR cigs will linger through the day
tomorrow, possibly impacting all TAF sites. Winds will diminish
late this evening but then increase between 5 and 10 knots, mainly
from the southwest, tomorrow afternoon.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...JMW
LONG TERM...KAS
AVIATION...JVM
Area Forecast Discussion
National Weather Service Lake Charles LA
1059 PM CDT THU SEP 8 2016
.DISCUSSION...
For the 09/09/16 0600 UTC TAF package.
&&
.AVIATION...
Some slight reductions to VSBY already noted, but as mentioned in
the previous aviation discussion, expect that any OBS lower than
VFR will be brief and sporadic. Thus, will continue to leave any
mention out of the forecasts. Previous package remains on target.
13
&&
.PREV DISCUSSION... /issued 859 PM CDT THU SEP 8 2016/
UPDATE...Convection continues to decrease this evening with only
a few showers left in the area. With the lose of diurnal heating
this trend will continue. The previous forecast remains on target
and no changes are needed at this time.
PREV DISCUSSION... /issued 629 PM CDT THU SEP 8 2016/
DISCUSSION...
For the 09/09/16 0000 UTC TAF package.
AVIATION...
Ongoing convection over parts of E TX into Central LA is not
expected to impact any terminal before dissipating over the next
hour or so. VFR to prevail through the overnight hours amid light
winds. Could see some light reductions to VSBY toward early
morning or a brief MVFR CIG as the CU field initially develops
around mid morning, but low confidence in either of these events
as well as their expected relatively short duration preclude
inclusion in the forecasts at this time. Light south winds with
isolated to scattered mainly afternoon convection expected. VCTS
inserted at all sites.
13
PREV DISCUSSION... /issued 359 PM CDT THU SEP 8 2016/
DISCUSSION...
Afternoon WV imagery and RAP 500 hPa height analysis show a broad
upper level ridge continues to extend across the Gulf Coast.
Scattered showers and thunderstorms have developed across SW LA
into SC LA in conjunction with diurnal heating. Given the lack of
significant forcing mechanisms across the area, convective
activity should diminish shortly after 0Z and this is supported
by higher resolution model guidance for this evening.
Further to the south, a vort max was noted in WV imagery over the
central Gulf. The vort max is associated with an inverted trough moving
westward that is forecast to move over SC TX on Friday.
26
Short Term...Friday through Sunday...
The short term period will be fairly active with several weather
features moving across the region. During the day on Friday, the
inverted trough over the central Gulf is forecast to move into TX
north of Corpus Christi. This will result in increased POPs across
SETX Friday. On Saturday and Sunday, another upper level trough
and associated surface boundary will approach the region from the
northwest that will result in even higher POPs/QPF.
26
Long Term...Monday through Friday...
For the long term period, the GEFS/EPS feature another mean
longwave trough setting up over the west coast with a ridge over
the east coast. This upper level pattern will result in an
increased fetch over the Gulf and increasing precipitable water
across the region. However, the NAEFS/GEFS/EPS mean precipitable
water all remain below two inches, corresponding to the 90th
percentile for September. Therefore, without any highly anomalous
moisture or height fields, expect a return to climatological POPs
and diurnal thunderstorm activity for next week.
26
MARINE...
A broad area of high pressure will continue over the southeast
U.S. and northern Gulf through early next week. The approach of
the front will shift the flow more easterly on Sunday and early
next week. At this time...weak onshore flow will continue.
26
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 73 92 72 91 / 10 20 10 30
LCH 76 90 75 90 / 10 30 10 40
LFT 75 91 75 90 / 10 40 10 30
BPT 77 91 76 90 / 20 30 10 40
&&
.LCH Watches/Warnings/Advisories...
LA...None.
TX...None.
GM...None.
&&
$$
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
904 PM CDT THU SEP 8 2016
.UPDATE...
Issued at 903 PM CDT Thu Sep 8 2016
Going forecast looks on track with just scattered showers
currently confined to parts of central and southeast Missouri
close to where the effective low level boundary is. Still expect
showers and thunderstorms to become more widespread late tonight
as low level moisture convergence over southern Missouri shifts
northeast toward I-70 toward sunrise per the RAP. This is
reflected by the HRRR which shows showers and thunderstorms
becoming more numerous across the CWA after midnight. Did lower
temperatures a degree or two based on current trends.
Britt
&&
.SHORT TERM... (Through Late Friday Afternoon)
Issued at 333 PM CDT Thu Sep 8 2016
(Tonight - Friday)
Main focus for tonight and Friday will be on the next round of
showers and thunderstorms which will affect the bi-state region
beginning late tonight. Expect a lull in precipitation after this
current wave of rain and a few storms pushes off to the south and
east of the CWA by early evening. Next round of organized convection
should initiate across eastern KS overnight tonight and grow upscale
into an MCS. Some uncertainty as to exact track of MCS and where the
core of it tracks across the CWA...but best guess is cutting right
through the central portion of the CWA...including the Columbia
and St. Louis metropolitan areas. NAM/GFS are further to the NW while
some short term guidance is even a bit to the southeast. Effective
baroclinic zone will be to the south of the CWA though will try and
return a bit northward overnight. Overlap of strongest low-level
warm/moist advection north of the boundary and large-scale ascent
associated from the vort max which was formerly Newton does seem
to paint the central CWA as the most likely region for this MCS
to track across. Widespread 1-2 inch amounts of rain appear likely.
Concern is for locally higher rainfall rates which could cause flash
flooding...particularly across portions of central Missouri which
received 1-3 inches of rainfall earlier today. Factors which swayed
toward not issuing a flash flood watch however include
1) uncertainty with placement of heaviest QPF amounts, 2) duration
of next round of showers/storms with the MCS look to be short-lived
and 3) FFG values remain high outside of a small portion of central
MO.
MCS is expected to clear the IL portion of the CWA by midday with
another break or lull in the coverage of showers and thunderstorms
forecast. Temperatures because of the MCS look problematic as thick cloud
cover even behind the MCS will likely help keep high temperatures down
a bit. Highs in the 80s are expected across the bi-state area...or some
10-15 degrees warmer than this afternoon`s temps. Strong synoptic cold
front will approach the far northwestern portion of the CWA toward late
dusk on Friday and will help provide the focus for the next round of
showers and thunderstorms.
Gosselin
.LONG TERM... (Friday Night through Next Thursday)
Issued at 333 PM CDT Thu Sep 8 2016
(Saturday - Sunday)
Period begins 00z Sat with the cdfnt just entering the nwrn portions
of the CWA. Expect two areas of precip to be ongoing at the
beginning of the period. One along/just ahead of the cdfnt, the
other in the WAA wing, which shud be E of the CWA, but with
redevelopment possible as a s/w approaches the region. The TSRA shud
gradually propagate ewd thru the CWA as the cdfnt pushes thru.
Expect the precip to largely be out of the area by sunrise Sat
morning.
A fairly strong sfc ridge builds into the area behind the fnt. Not
much change in max temp forecast thru the period. Did lower temps
Sat night, especially across portions of the Ozarks, as the sfc
ridge settles over the region with light winds and a clear sky are
expected.
(Monday - Thursday)
Period begins with a brief warmup as the sfc ridge builds ewd and
sly flow returns. Precip chances increase by mid-week as another
cdfnt approaches the region. Cooler temps again as the sfc ride
builds into the area again late in the period.
Tilly
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 654 PM CDT Thu Sep 8 2016
MVFR ceilings will persist at KUIN and KCOU this evening and then
spread eastward to the KSTL metro TAF sites by around 09Z as a new
wave of rain and scattered thunderstorms moves in. The primary
threat for lightning should remain south of all TAF sites, but
have included a VCTS due to threat of some in cloud lightning.
Rain should end from west to east during the morning leaving
mostly VFR ceilings.
SPECIFICS FOR KSTL: VFR ceilings and visibilities should last
until at least 09Z. Next wave of rain and embedded thunderstorms
will move in after that time with ceilings and visibilities falling
to MVFR category. While most of the lightning should remain south
of the KSTL metro TAF sites, have included a VCTS for the threat
of some in cloud lightning. Rain should end by around 14Z with
ceilings improving to VFR.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Lubbock TX
619 PM CDT THU SEP 8 2016
.AVIATION...
VFR conditions will prevail through the TAF cycle.
&&
.PREV DISCUSSION... /issued 232 PM CDT THU SEP 8 2016/
SHORT TERM...
Surface flow across the forecast area has been from a southwesterly
direction much of the day. Winds off the caprock are beginning to
back, however. This is in an area where temperatures in the lower to
middle 90s and dew point temperatures near 70. The backing of the
low level flow may be what it takes to see some isolated showers
develop in this part of the area. Model runs are mostly dry for late
afternoon and evening, but the RAP has consistently been showing
another SW-NE swath of precipitation developing, and what seems to
be setting up might verify that solution. As a result, will run with
a slight chance across roughly the eastern column of counties for
this evening. Will also extend that into the overnight hours. Deep
moisture lingers across the Rolling Plains, although not as rich as
it has been the last several days. Proclivity to see some elevated
nocturnal convection develop in this type of setup cannot be
ignored.
Focus for Friday shifts to afternoon precipitation chances. A
cold front will move into the Panhandle late in the day. South of
this front the overall surface pattern will be similar to today.
Winds will initially be veered toward the southwest but will begin
to back during the afternoon. Aloft, a weak mid level trough
located over New Mexico today will shift overhead for Friday.
Slight cooler temperatures in the mid levels in association with
this feature and slightly warmer temperatures at the surface south
of the front should result in some convective precipitation
developing, areas east of the I-27 corridor favored at this time.
LONG TERM...
Whats left of Newton will still have some influence on our weather
heading into the weekend. Newtons remnants will graze West Texas
while being absorbed into the polar jet and may even trigger some
convection Friday afternoon across our eastern zones out ahead of
a cold front advancing south from the Texas Panhandle Friday night
into the early hours of Saturday. The window for any severe
tstorms hinted at in earlier model runs seems to be narrowing,
especially for our CWA. Though much of area will see some precip
with the front by early Saturday morning, highest amounts appear
to be in the Rolling Plains and southern South Plains.
We dry quickly behind the cold front Saturday, along with
weakening pressure gradient, winds will be light Saturday night
setting up for one our cooler nights in awhile with most locations
on the Caprock dropping into the 50s, slightly warmer to the east
off the Caprock. High temps rebound to seasonal norms for the
most part on Sunday and Monday while the next system strengthens
across the west. GFS and ECMWF have come into good agreement on an
unsettled pattern for the middle of next week that could bring
another round of impactful precip amounts.
&&
.LUB Watches/Warnings/Advisories...
None.
&&
$$
51
Area Forecast Discussion
National Weather Service Mount Holly NJ
914 PM EDT THU SEP 8 2016
.SYNOPSIS...
High pressure will remain south of the area through the weekend. Low
pressure and a weak cold front will cross the area later Friday,
followed by a stronger front Saturday night and early Sunday. High
pressure will arrive for early next week. Another disturbance will
approach the area towards the middle of next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Line of showers and thunderstorms over central PA diminishing in
intensity as it tracks east. Models indicating upwards of 1000
J/kg of ML MUCAPE across the region, but there is also a fair
amount of CIN across the region as well, which is helping to cut
back on those storms as they track east. HRRR continues to
indicate storms developing over SE PA and into NJ after midnight
tonight, so will keep slight chance/low chance PoPs in the
forecast.
A hot and muggy night on tap for tonight. In metro areas, such as
Philly and Trenton, temps are still in the upper 80s, which for
most other areas, temps have fallen into the upper 70s to low 80s.
Meanwhile, surface dewpoints remain in the 70s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Record heat forecast and 08/09z modeled SREF pwat is still around
2 inches PHL. This suggests contd high dewpoints along and south
of I-78 and around 100F HI for PHL RDG ABE and 105-110 for KESN.
That plus coming off an overnight low in the upper 70s and we`ve
extended the heat advisory. (Another NPW heat advisory extension
for Saturday may be needed tomorrow)
There could be scattered mid-late afternoon thunderstorms Friday
in the PWAT KI instability AXIS vcnty KRDG-KTTN to maybe just
north of KPHL. Question is the lift? Could be a sea breezes in NJ
or a leftover wind shift from whatever moves in later tonight?
Appears capped Delmarva with near 10C at 700mb and -5C at 500MB
in a 578dm 1000-500 thickness. Modeled MLC is now similar to that
of this afternoon...aligned fm CXY-SE pa through TTN -central NJ.
Fcst elements were a 50 50 blend of the 12z/8 GFS/MOS guidance
with the temps raised 2F because of the GFS/NAM/EC 2m temps being
2-4F warmer than the 12z/8 predicted values for 18z today.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
The period from Friday night thru Sunday morning will feature a
continuation of summer-like weather with well above normal
temperatures and high humidity values. There will be two
opportunities for sct showers and tstms. The first will be Fri
night as a weak cold front will be crossing thru the region. A
stronger front later Sat and Sat night will bring a better chc for
tstms. Gusty winds and downpours possible with tstms.
After the front crosses the area Sunday, drier and a bit cooler
air will arrive across the area. The period should be mostly dry.
Temperatures will only be a few degrees above normal Sunday thru
Tue with highs mostly in the mid 80 across the metro areas.
The longer range models are showing another front approaching
around the mid-week period. We have mentioned some low chc pops
for this feature. Temperatures will climb back to well above
normal by Wed. Then cooler air for the later part of next week.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Mainly VFR. Brief MVFR VSBYs possible in scattered SHRA
and isolated TSRA at KABE/KRDG/KTTN late tonight with passage of
decaying squall line. SW winds diminish to 5 KT or less.
Friday...VFR with sct-bkn clouds aoa 5000 ft in the afternoon.
Chance of SHRA/TSRA at KRDG/KABE/KTTN and possibly KPNE. Will
introduce PROB30 groups for KRDG/KABE, but confidence is low in
TSRA occurring at those given terminals. Light W to NW wind with a
sea breeze on the coasts.
OUTLOOK...
Friday night...Sct showers and tstms with lower conds psbl.
Sat...Mostly VFR/Hazy. Sct tstms during the afternoon.
Sat night/Early sun...Sct tstms with lower conds psbl.
Sun thru Tue...Mostly VFR.
&&
.MARINE...
No marine headlines through Friday. S to SW winds along the
coasts this afternoon and again Friday afternoon and W to SW winds
tonight. Winds may gust to 20 KT through this evening.
OUTLOOK...
Fri night and Sat...Mostly sub-sca conditions with sct tstms.
Sat night and early Sun...SCA seas psbl on the ocean with sct
tstms.
Sun thru Tue...Mostly sub-sca conditions.
RIP CURRENTS...the low risk for the formation of dangerous rip
currents is expected through Friday.
&&
.CLIMATE...
Heat (4-6 day heat wave) in progress as we go through this week.
Heat wave count as of today: ILG 3 days; PHL ABE RDG 2 days so far.
RER equaled at ABE yesterday.
RERGED today all other stations with2f of record except for KMPO.
Here are the record high temperatures for Today through
Saturday...the hottest days in this stretch.
Today- 9/8 Friday- 9/9 Saturday 9/10
ACY 94-1939 92-1915 95-1983
PHL 96-1939 94-1884 97-1983
ILG 95-1939 94-1939, 1915 98-1983
ABE 97-1939 95-2015 96,1983
TTN 95-1939 93-1959 101,1983
GED 92-2015 92-2015, 1985 93,1985
RDG 96-1939 94-2015, 1959 100,1983
MPO 88-2015 88-1964 89,1983
RER # 90 deg days: Season total, Season RER, Sept rer, Sept mean
then closing out with Season rank and POR. You can see in the period
of record (POR) that the number of 90 degree days this year will be
top 5 in the detailed historical record.
The 90 degree data below is through yesterday September 7.
2016 RER 9/RER 9/Mean Season rank POR
ABE 34 41-1966 7-2015 1 #5 prob rise to #2-3 1922
ACY 29 46-2010 9-1961 1 #6 now could tie #4 1874
PHL 42 55-2010 8-1970 2 #5 1872
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 6 PM EDT Friday for PAZ060>062-070-071-
101>106.
NJ...Heat Advisory until 6 PM EDT Friday for NJZ015-017>019.
DE...Heat Advisory until 6 PM EDT Friday for DEZ001>003.
MD...Heat Advisory until 6 PM EDT Friday for MDZ008-012-015-019-020.
MARINE...None.
&&
$$
Synopsis...O`Hara
Near Term...Drag/MPS
Short Term...Drag
Long Term...O`Hara
Aviation...Drag/MPS/O`Hara
Marine...Drag/O`Hara
Climate...
Area Forecast Discussion
National Weather Service Springfield MO
911 PM CDT THU SEP 8 2016
.UPDATE...
Issued at 843 PM CDT Thu Sep 8 2016
In coordination with WFO ICT added a few counties to the south for
the Flash Flood Watch.
Continuing to see activity develop in high pwat environment over
se KS/ne OK and drift into our western cwfa. This is occurring
ahead of subtle upper level shortwave over sw KS into OK. That
area is also being fed by sw low level (850mb) flow which is
expected to increase somewhat over the next few hours. Clusters of
heavy rain producing storms will continue for a few more hours.
The low level flow will veer and weaken late tonight into early
Fri as the upper level disturbance also shifts east. HRRR has
been consistent with a temporary slow down or lull in the precip
toward daybreak Fri.
Severe storm risk is very low, but some non-zero risk for a wet
downburst exists over the far western cwfa this evening.
&&
.SHORT TERM...(This evening through Friday Night)
Issued at 345 PM CDT Thu Sep 8 2016
Scattered storms and showers are currently spreading east across
the area and will continue through the late afternoon hours and
will dissipate from west to east early this evening. Deep layer
shear is on the weak side and therefore will limit the severe
risk with this activity. Wind gusts up to 40mph, cloud to ground
lightning, and brief heavy rain will occur with the stronger storms
this afternoon into early this evening.
Additional storms will develop across central Kansas this evening as
an upper level disturbance tracks across the region. This activity
will spread north across portions of western and central Missouri
tonight. A band of heavy rainfall is expected with this activity
across these locations tonight. This band will likely track north
of a line from Pittsburg Kansas to Lake of the Ozarks, but the
exact track could shift slightly north of south. No severe
weather will occur, but tropical influence from the remnants of
Newton could lead to efficient rain amounts in a narrow band
tonight.
Scattered storms will be possible during the day on Friday but
should not be widespread in nature and should dissipate by early
Friday evening.
An upper level trough will then dive south into the Plains Friday
night and will send a cold front to the southeast. Storms are
expected to develop to the north of the area Friday
afternoon/early evening and spread south into the area Friday
evening and night.
The storms should remain north of I-44 Friday
evening and then move south during the overnight hours.
Instability will weaken through the night, so the showers and
storms are expected to weaken as they spread south across the
area, and could dissipate all together by the time they reach
south central Missouri early Saturday morning. Deep layer shear
will increase across the region as the upper level trough
approaches from the west. The deep layer severe and expected
instability across the region will support a severe risk across
the northern half of the forecast area, generally along and north
of I-44. Mid level lapse rates and warm temperatures in the mid
levels will limit the hail potential. A few of the strongest
storms may be capable of penny size hail but the main severe risk
will be damaging straight line winds and will be isolated in
nature with line segments that can develop.
Additional heavy rainfall will be possible with the storms along
the front. The intensity in the rainfall will decrease from north
to south, especially south of I-44, as the storms weaken. The
heaviest rainfall from the round tonight and again with the round on
Friday night is expected to be across east central Kansas and west
central Missouri where the Flash Flood Watch is effect for.
Therefore, no adjustments are expected to the watch at this time
and will leave as is as these locations are expected to see the
heaviest rainfall amounts of 3 to 4 inches. Else where across the
area generally 1 to 3 inches are expected.
.LONG TERM...(Saturday through Thursday)
Issued at 345 PM CDT Thu Sep 8 2016
A few linger showers may occur across south central Missouri
Saturday morning but will end quickly during the morning hours. A
cooler and drier air mass will spread over the region behind the
front. Highs on Saturday and Sunday afternoons will be in the 70s
as lows in the upper 40s to the lower 50s occur Saturday night
into Sunday morning.
Temperatures will then warm back to near normal with readings in
the lower to middle 80s early next week. Another upper level
trough and cold front will track across the region by the middle
of next week. The front will bring additional chances for showers
and storms to the area along with cooler conditions.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 843 PM CDT Thu Sep 8 2016
For the KSGF/KJLN/KBBG tafs: Scattered storms will continue for
the next few hours with the best chances at KJLN. MVFR or brief
IFR conditions will occur with heavier showers. Will need to
monitor for low ceilings toward 12z with a lot of moisture in the
lower levels form recent showers.
&&
.SGF Watches/Warnings/Advisories...
MO...Flash Flood Watch through Saturday morning for MOZ055>057-
066>070-077>081-088>095.
KS...Flash Flood Watch through Saturday morning for KSZ073-097-101.
&&
$$
UPDATE...DSA
SHORT TERM...Wise
LONG TERM...Wise
AVIATION...DSA
Area Forecast Discussion
National Weather Service La Crosse WI
309 AM CDT FRI SEP 9 2016
.SHORT TERM...(Today through Monday)
Issued at 309 AM CDT Fri Sep 9 2016
Sheesh....more rain? Seems like we can`t catch a break in the
rainfall department lately, with the next 24-36 hours expected to
bring at least one if not a couple of additional rounds of showers
and storms, with at least a small risk for some to be on the
stronger side. The early morning pattern looks an awful lot like it
should this time of year, featuring a rather broad upper trough
digging through the northern Rockies with several embedded stronger
shortwaves. One such lead wave is currently working through southern
South Dakota and helping touch off a smattering of convection, with
another in tow across northern Wyoming and a third, much stronger
primary upper wave streaming into northeast Montana. Closer to home,
quite the dry airmass intact across much of our area at the moment,
but that quickly changes just to the south with a notable surge of
deeper 850-800mb moisture working back north through northeast
Nebraska and into northwest Iowa, quickly headed here through the
morning hours on the nose of a modest low level jet.
As such, see no real reason why current convection upstream won`t
upscale through at least mid morning, with effective shear on the
order of 40+ knots supportive of supercellular characteristics with
mainly a hail threat given the elevated nature of convection (have
seen some of this to our west overnight). In addition, given a quick
increase in warm cloud depth to around 3.5-4km once again with PWATs
climbing toward 1.5 inches, have to again worry about some heavy
rain potential, especially if organized storms can lay out along the
northward advancing warm front, though given much better upper
dynamic forcing from the lead wave, would think convection will tend
to be more progressive than recent days. However, the simple fact is
we just can`t take much more water across northeast IA/southwest WI
where 1 hour flash flood guidance is only around a meager inch or
so.
After round 1, we will likely see things spit and sputter into the
afternoon with the approach of wave number 2, though the degree of
available instability remains somewhat in question pending how much
sunshine we can manage. Have a feeling we may break out enough into
the afternoon in advance of the third incoming stronger wave/cold
front to achieve some modest instability in the presence of still
rather impressive shear. Interesting to see recent runs of the HRRR
trying to sneak a frontal wave right through the region, with the
conceptual pattern ripe for supercell development right along the
cold front. Given the potential for some backed flow should that
surface wave actually occur, do have at least a little concern we
may be setting up for a sneaky localized tornado environment across
particularly northeast Iowa, though rather paltry 0-1km shear will
preclude a specific mention at this point, with large hail/damaging
winds from supercellular structures right along the front the main
concern.
Thankfully, not much else to discuss thereafter, with the passage of
the cold front ending our convective chances through the late
evening. Stronger low/mid level cyclonic flow working into the
region coincident with quite the push of cold advection will likely
act to keep at least chances for some "wrap around" showers going
for north and east areas into the day on Saturday, before strong
drying and expansive low level ridging working through the area
bring in another shot of early fall weather with seasonable temps
and pretty much no threat for rain.
.LONG TERM...(Monday Night through Thursday)
Issued at 309 AM CDT Fri Sep 9 2016
The classic September roller coaster type of pattern looks to
continue through late week, with high pressure working east of the
area and helping set up better return flow across the region by
Tuesday, just in time for our next cold front to arrive. Will have
some chance for showers and maybe a little thunder with that
feature, before our next surge of even cooler air arrives into mid
and late week along with high pressure and more much-needed dry
weather.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1158 PM CDT Thu Sep 8 2016
Periods of showers and thunderstorms are expected at the TAF
sites early Friday morning into Friday afternoon. IFR conditions
are possible in the heavier storms at times with visibilities
falling to around 2 SM and ceilings dropping to around 1kft. Also,
some of the storms may become severe with large hail and gusty
winds. Showers and storms will push east of the TAF sites by late
Friday evening.
&&
.HYDROLOGY...
Issued at 309 AM CDT Fri Sep 9 2016
Minor flooding continues along the Kickapoo River but with water
levels now falling north of Gays Mills while some flooding also
continues across portions of Richland County along the Pine River.
Heading into today and this evening, continue to have concern about
one or two rounds of additional showers and storms moving through
the region. From a pattern perspective, the setup is not nearly as
good as in recent days for widespread heavy rainfall with batches of
storms expected to move along at a decent speed, though any repeated
rounds of storms could put down some isolated 2-3 inch amounts.
Given how low flash flood guidance remains across mainly northeast
Iowa into parts of southwest Wisconsin with very wet soils, there is
some risk for flooding depending on the evolution of convection the
next 24 hours, though confidence at the moment is just not there as
of yet to issue any type of Flood Watch. Thankfully, after this
batch of precipitation, dry weather will make a return into early
next week, with only smaller chances for some more showers toward
Tuesday of next week.
&&
.ARX Watches/Warnings/Advisories...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Lawrence
LONG TERM...Lawrence
AVIATION...WETENKAMP
HYDROLOGY...Lawrence
Area Forecast Discussion
National Weather Service Billings MT
324 AM MDT FRI SEP 9 2016
.SHORT TERM...valid for Tdy and Sat...
RAP 300 MB analysis shows 90-100 kt jet streak extending from
western Idaho through central Wyoming. This favored jet position
is allowing scattered showers to develop from YNP through
southeastern Montana. Isolated showers will be a possibility from
Livingston through Broadus in the early morning hours where
favored frontogenesis and jet support resides as the jet kicks
eastward. A front slides south from Canada bringing scattered
showers with an isolated thunderstorm possible to the eastern half
of the CWA. Cloudy skies begin to clear on Saturday as ridging
builds in from the west. Low-level westerly flow will aid
downsloping, brining warmer and drier conditions to the area.
Expect highs into the low to mid 80s with humidity values around
15 percent with no rain. Walsh
.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...
Extended forecast starts out with zonal westerly flow ahead of
strong Canadian cold front that will arrive Sunday
afternoon/evening. Temperatures Sunday will depend entirely on the
arrival time of the front with some models suggesting a late
morning arrival and others early evening. For now split the
difference with temperatures ranging from the 60s northwest to the
80s southeast. It will take a bit of time for atmosphere to
saturate up but by late evening expect a good chance of
precipitation over the northwest half of the forecast
area...spreading southeast overnight.
Upslope winds deepen up to keep good chances of precipitation
going into Monday evening, especially for mountain/foothill
locations. 700mb temperatures drop to -5c/850mb to +3c by Monday
morning behind the front which should push snow levels down to
about 6500 feet. Expect a dusting of snow in the higher foothills,
with several inches of snow in the mountains, which could impact
the Beartooth Highway and US14 over the Bighorn Mountains. For
lower elevations a cold rain could add up to over a quarter of an
inch over a broad area Sunday night through Monday.
Tuesday into Wednesday sees a dry and warmer forecast as upper
trof shifts east and drags the 1030mb high into the plains.
A chunk of energy from the trof cuts off and drifts southwest
into northern California, then gets kicked back into the northern
Rockies Wednesday night into Friday. GFS ensemble mean and ECMWF
agree on pushing this energy over the area providing another shot
of showers and thunderstorms for the end of the week. Chambers
&&
.AVIATION...
An area of showers will continue across the far southern portion
of the forecast area through sunrise morning, impacting KSHR and
the Bighorn foothills/mountains. Expect IFR conditions in the
mountains with mvfr/vfr conditions in the lower elevations with
this activity. Another area of showers will rotate into the area
from the north this morning with more widespread vfr/mvfr
conditions. Gusty northwest winds (30kts) are expected this
morning especially near any shower activity. Wind speeds are
expected to taper off this afternoon. Flight conditions will be
improved by mid to late afternoon as shower activity shifts
southeast. Chambers
&&
.PRELIMINARY POINT TEMP/POPS...
Tdy Sat Sun Mon Tue Wed Thu
-------------------------------------------------------
BIL 067 047/081 052/079 044/052 039/063 043/073 050/070
2/W 00/U 01/B 65/W 31/B 12/T 33/T
LVM 067 040/080 045/074 039/049 032/058 038/070 043/071
1/N 00/N 02/T 66/W 31/B 12/T 22/T
HDN 068 043/082 048/080 045/054 040/066 044/076 050/071
2/T 00/U 01/U 54/W 31/B 11/U 33/T
MLS 067 045/081 051/080 046/056 041/066 046/077 052/075
3/T 10/U 00/U 32/W 21/B 11/U 22/T
4BQ 063 043/080 049/082 047/056 041/065 047/077 051/075
3/T 10/U 00/U 23/W 21/B 11/U 22/T
BHK 063 043/077 048/078 047/056 039/063 045/074 051/074
3/T 20/U 00/U 32/W 11/B 11/U 22/T
SHR 064 041/080 047/080 044/050 037/062 042/073 046/070
2/W 00/U 00/U 46/W 42/W 11/U 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service State College PA
323 AM EDT FRI SEP 9 2016
.SYNOPSIS...
The strong ridge aloft over the MS/OH valleys will keep us much
warmer than normal through the end of the week. Muggy air will
stick around until a strong cold front passes this weekend. After
a day or two of seasonable temperatures Sunday and Monday another
warm- up will occur.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Early morning WV loop showing main shortwave tracking across
southern Quebec. Trailing low lvl jet and assoc plume of anomalous
PWATS is sliding south across Pa, accompanied by a dwindling band
of showers. HRRR supports the idea of highest (likely) Pops for
the remaining of the night along the I-80 corridor, with only a
slight chc of showers over the northern and southern tiers.
Overcast skies should preclude sig fog issues.
It will remain a muggy and unseasonably warm night...with
lows ranging from the upper 60s over the nw Mtns, to the mid 70s
across the Lower Susq Valley.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
With baroclinic zone bisecting the commonwealth on Friday...there
will be much more cloud cover than Thursday. Upper ridge will
actually rebound slightly on Friday afternoon as digging trof
approaching the Ohio valley late in the day. This will allow the
south and southeast to bake once again with apparent temps once
again in the mid 90s. Deep layer moisture will be farther south.
Large scale forcing will be non existent...but after a morning
lull expect sct diurnal convection to develop during the aftn across
the southern half in conjunction with anomalous PW. Still...Friday
should be the least active of today through Saturday overall.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Mid-scale trof digging over the northern Plains is forecast to
swing through the Northeast and northern Mid Atlantic regions near
the start of the long term period and into the weekend, with the
subtropical ridge rebuilding early next week. This trof and
associated surface cold front should support the hiest chances of
pcpn during the period.
Behind the front, a return to dry weather is in store. It will
be noticeably cooler on Monday, but then turn warm again Tuesday
and Wednesday as the upper ridge rebuilds northward.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Weak frontal boundary across central mountains is focus for
a band of generally light rain extending from DUJ/FIG to UNV to
near IPT. North of the front, cig restrictions settling into IFR
while VFR continues to the south.
By mid morning Fri, remaining showers should be diminishing with a
several hour lull in convection. Cig restrictions should finally
lift over the northern half between 14Z-16Z, though thick mid-deck
will persist. Large scale forcing will be non-existent...but
after the morning lull expect sct diurnal convection to develop
during the aftn mainly across the southern half.
Scattered convection persists into Fri night as upper trough digs
over Ohio Valley. Cig restrictions return to the NW.
Outlook...
Fri...AM low cigs n mtns. Local restrictions in sct TSRA south.
Sat...Isold PM tsra impacts possible, mainly w mtns.
Sun...AM log cigs possible w mtns.
Mon-Tue...No sig wx.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Synopsis...DeVoir/La Corte
Near Term...Fitzgerald
Short Term...DeVoir/Fitzgerald
Long Term...Gartner
Aviation...Ceru/RXR
Area Forecast Discussion
National Weather Service Des Moines IA
332 AM CDT Fri Sep 9 2016
.SHORT TERM.../Today/
Issued at 328 AM CDT Fri Sep 9 2016
Main challenges today will be convection and temperatures. First
impressions...models not doing very well early this morning. At
0730z there is little convection over northwest/western Iowa while
most of the hires models suggested that areal coverage of
thunderstorms would be filling into this area by now. Isolated weak
convection has attempted to develop near Denison/Carroll...but it is
having difficulty holding together. Subjective 03z surface shows a
weak stationary front across southern Iowa...tied to a low over
north central Nebraska. Aloft at H850...flow remains weak over most
of Iowa from the south/southwest at 10-15kts while slightly stronger
flow of 10 to 20kts is persisting in Nebraska. There is also a warm
front aloft which is most likely resulting in the convection now
over eastern South Dakota/western MN. The general lack of convection
at 0730z might be tied to the stronger MCS south in Kansas-Missouri.
As a result of the situation...have trimmed back PoP northwest
through 11-12z and gradually increase across north/north central
through 18z...keeping most of south central dry for now. The push of
mainly stratiform precipitation over northern Missouri may affect
the southeast through 18z. A slightly more consistent picture is
expected this afternoon as the cool front/low sweeps east into the
area.
The weak Nebraska surface low will track into Iowa later this
morning keeping the south in the warm sector. Shower and thunder
chances will remain north with generally increasing chances again
northwest to southeast through 00z. The ESRL HRRR...NMM...ARW and
most of the synoptic models agree that the front will begin to light
up during the afternoon. The initial surge of instability along the
boundary over western/southwest Iowa should be the main concern for
severe weather into the mid to late afternoon hours. This area will
have longer to recover and remain undisturbed for most of the day.
Bulk shear is not particularly strong but enough at 25 to 40kt to
support severe weather with wind and hail the main concerns.
Sufficient cape to 1600-2000 J/KG over the west will diminish
quickly into the evening hours though shear increases behind the
boundary. H850 moisture analysis at 00z shows tropical remnants of
Newton now extending from Texas to Nebraska and this will feed into
the front today. Precipitable water forecast is between 1.5 and 1.75
this afternoon. With some focus along the front the potential for a
1 to 2 inch rainfall is possible. We continue outlooked for a slight
risk of excessive rainfall today through evening. Though the risk is
there...it remains more isolated due to the expectation that the
front will push the storms along as it moves east. 1 hour flash
flood guidance is at least 1.5 inches or higher...with 3 hour at
least 1.75 inches or higher. The areas which experienced heavier
rainfall Tuesday through Wednesday evening may experience minor
runoff issues if some of the storms manage to output up to 2
inches/hour. Typical urban runoff is also possible in the metro
areas as well. The storms are progged to affect the I35 corridor
and the Des Moines area by 23-00z...so this line may impact rush
hour traffic later today. For now will not highlight any areas with
headlines given storm movement of 20 to 25kts should offset rainfall
rates. Highs today will recover into the mid 70s north to the lower
80s in central and southern areas.
.LONG TERM.../Tonight through Thursday/
Issued at 328 AM CDT Fri Sep 9 2016
Forecast focus is on lingering storm chances tonight...with drier
and pleasant conditions this weekend into early next week.
Tonight: Forecast Confidence = Medium
An MCS or broken line of storms is expected to be ongoing at the
beginning of the period along a cold front that will bisect Iowa
from NE to SW at 00Z Saturday. The front and associated storms
should remain fairly progressive as they move off to the
east/southeast. The latest CAM guidance from the NSSL WRF, 4KM NAM
NEST, WRF ARW/NMM, and ESRL HRRR indicate that a majority of the
storms should exit the area by 06-09Z Saturday. The primary severe
threat this evening and tonight /conditional on instability/ will
likely be damaging winds, due to linear MCS mode, along with
locally heavy rainfall. Behind the cold front, breezy northwest
winds will advect in a cooler and drier airmass. Lows tonight
should fall into the 50s.
Saturday through Monday: Forecast Confidence = High
Surface high pressure will build into the Midwest in the wake of the
aforementioned cold front which will result in a stretch of
fantastic weather from Saturday through Monday. Could see some
residual cloudiness Saturday morning, otherwise expect Saturday to
be a breezy day with northwest winds of 15 to 25 mph due to a fairly
tight pressure gradient and subsidence in the wake of the upper
shortwave. H8 temps in the 8C to 10C range will keep highs in the
upper 60s and lower 70s. Southerly return flow on the backside of
the surface high will lead to a moderation in temps on Sunday and
Monday with highs in the 70s to lower 80s. Dewpoint values will
generally be in the 50s, very comfortable.
Monday Night through Thursday: Forecast Confidence = Medium/High
The 00z suite of models have slowed the next upper trough and
associated cold front a bit, but is still expected to impact the
area from Monday night into Tuesday, resulting in a chance of
showers/tstms, especially over southern Iowa. In the wake of this
frontal passage, a strong Canadian high pressure system is expected
to move into the region on Wed-Thu with the possibility of some of
the coolest weather of the season thus far. Highs on Tuesday and
Wednesday will likely remain in the 60s with lows in the 40s over
northern Iowa on Tuesday night.
&&
.AVIATION.../For the 06Z TAFS through 06Z Friday night/
Issued at 1120 PM CDT Thu Sep 8 2016
Instability increases especially after 06z as increasing low level
moisture works in. MVFR conditions to move in with shra/tsra and
potentially some MVFR fog as well. Most likely scenario is for
precip across northern TAF locations before 12Z with low cigs and
fog elsewhere. A break in widespread precip between 12z and 18-19z
then storms along a fropa across TAF locations through 02z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...REV
LONG TERM...Fowle
AVIATION...FAB
Area Forecast Discussion
National Weather Service Lincoln IL
321 AM CDT FRI SEP 9 2016
.SHORT TERM...(Today and tonight)
ISSUED AT 321 AM CDT Fri Sep 9 2016
07z/2am surface analysis shows a 1006mb low over southwest Kansas,
with a stationary frontal boundary extending eastward into the
Ozarks. A large complex of thunderstorms has developed ahead of
this system across eastern Kansas into western Missouri, while
another smaller cluster of storms has formed further east near the
Saint Louis area. These storms will lift northeastward into the
KILX CWA early this morning, albeit in a weakening state as they
track further away from a 25-30kt 850mb jet streak oriented from
Texas N/NE into Missouri. HRRR seems to have a reasonable handle on
the situation, so have followed its solution closely for the
immediate short-term. Based on HRRR and latest radar trends, have
focused likely to categorical PoPs along/south of a Rushville to
Paris line this morning into the early afternoon...followed by
decreasing PoPs later in the day. Before the precipitation arrives,
widespread dense fog will be an issue across nearly the entire area
early this morning. Despite a high/thin overcast, very light winds
and temp/dewpoint spreads of 0-1F have led to fog development...with
07z obs showing visibilities less than 1 mile everywhere north of
the I-70 corridor. The fog will dissipate as showers push into the
area from the southwest: however, it appears several hours of
greatly reduced visbys will occur. As a result, have issued a Dense
Fog Advisory across all but the far SW and SE CWA through 14z/9am.
A vigorous short-wave trough evident on latest water vapor imagery
over Montana/Idaho will track eastward later today and tonight,
pushing a cold front toward Illinois. Numerous showers and
thunderstorms will develop within the increasingly moist airmass
ahead of the front. With precipitable water values once again
expected to exceed 2 inches, heavy rainfall and localized flash
flooding will be possible with the thunderstorms tonight. Since
rainfall amounts are expected to be less than previously forecast
with the initial surge of convection this morning, do not think
widespread flash flooding will be a major threat tonight.
Therefore...do not feel a Flash Flood Watch is warranted at this
time.
&&
.LONG TERM...(Saturday through Thursday)
ISSUED AT 321 AM CDT Fri Sep 9 2016
Cold front will swing through central Illinois on Saturday, with
showers and thunderstorms lingering across the east through the
morning. Once the front passes, brisk W/NW winds gusting to between
20 and 25 mph will usher a cooler and drier airmass into the region.
As skies clear and winds diminish, low temperatures will drop into
the upper 40s and lower 50s Saturday night. The cool/dry weather
will persist for both Sunday and Monday, with highs in the 70s and
lows in the 50s.
A brief warm-up is expected for Tuesday ahead of the next
approaching cold front when temperatures return to the lower 80s.
00z Sep 9 models are in good agreement with FROPA Tuesday night into
early Wednesday. Have therefore introduced low chance PoPs in the
Illinois River Valley on Tuesday, then everywhere Tuesday night.
After that, cooler/drier weather will return for Wednesday and
Thursday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1151 PM CDT Thu Sep 8 2016
Based on local observations, fog is beginning to develop in some
areas. Believe all TAF sites will eventually see fog in the next
few hours, becoming MVFR with TEMPO of IFR or LIFR at all sites.
Some of the short range models show stratus developing as well,
but have some reservations with that forecast, so only have cigs
below 1kft in TEMPO groups. Conditions will only slightly improve
during the morning hours as the next wave of precip will move
northeast into the area with showers and possible thunderstorms.
These MVFR conditions will continue through the afternoon. But
with another around of more precip for the evening, MVFR
conditions will continue with moderate rain and thunderstorms.
Winds will be light and variable overnight, but then become
southeast to south during the day and into the evening.
&&
.ILX Watches/Warnings/Advisories...
Dense Fog Advisory until 9 AM CDT this morning for ILZ027>031-
036>038-040>048-051>057-061>063.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
Area Forecast Discussion
National Weather Service Indianapolis IN
424 AM EDT FRI SEP 9 2016
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 339 AM EDT Fri Sep 9 2016
Periodic chances for showers and storms will continue in a warm and
humid airmass through Saturday until a cold front can move through
central Indiana. Behind the front...cooler and much drier air will
overspread the Ohio Valley into early next week. A frontal boundary
will bring the next chance for storms the middle of next week.
&&
.NEAR TERM /Today/...
Issued at 339 AM EDT Fri Sep 9 2016
Convection has largely ceased over the forecast area for the time
being as the front has shifted south of central Indiana...with the
exception of some isolated activity over the southwest counties.
Left in the wake of the heavy rain and storms are pockets of low
stratus and fog in the soupy airmass. 07Z temps ranged from the
upper 60s to lower 70s in most locations.
Several issues at play for today...first is the expected expansion
of both low stratus and fog through daybreak...followed by renewed
convective development later today with the return of the frontal
boundary north into the forecast area.
So far...dense fog has remained relatively isolated and primarily
focused over the northern Wabash Valley where skies have cleared.
With that being said...11-3.9 micron satellite imagery showing
expanding pockets of stratus generally under 1000ft with higher
convective cloud debris expanding northeast from the mid Mississippi
Valley. The clouds may further limit more widespread fog development
over the next few hours...but short range guidance led by the HRRR
favoring potential for more widespread low visibilities developing
over much of the northern half of the forecast area over the next
few hours. With visibilities not out of control yet...have no plans
to issue a dense fog advisory and will instead take a wait and see
approach.
Whatever fog and low stratus is around at daybreak may take some
time to mix out with stagnant flow in the low levels initially.
Model soundings showing an abundance of low level moisture which
will likely keep much of the area mostly cloudy today. The frontal
boundary will lift northeast out of the mid Mississippi Valley in
response to the amplifying upper trough tracking across the northern
Plains and contributing to cyclogenesis by late day in the upper
Midwest. Ongoing convection along the boundary from Missouri into
western Kentucky will track northeast with the boundary and is
likely to expand into the forecast area in a weakened state by mid
morning and may bring additional rain to the area into the
afternoon. Hi-res guidance continues to favor convective development
over eastern Missouri and Illinois by late afternoon at the nose of
an approaching low level jet. Most of this activity should hold off
from expanding into the forecast area until the evening.
Once again...locally heavy rainfall will be the primary concern from
showers and storms later today with a juiced airmass and precip
water values at or above 1.5 inches over the southern half of the
forecast area. This will become an even greater factor tonight as
the low level jet expands into the area.
Temps...prefer the cooler MAVMOS today with abundant cloud cover
anticipated. It will remain humid with highs generally making it
into the lower 80s.
&&
.SHORT TERM /Tonight through Sunday Night/...
Issued at 339 AM EDT Fri Sep 9 2016
Forecast challenges focus on rainfall and storms tonight into
Saturday morning and again potentially Saturday afternoon before a
cold front clears the area.
Convection developing to our west is expected to overspread the
forecast area during the evening as the aforementioned low level jet
expands and increases across central Indiana. The deeper tropical
moisture plume will be pulled north into the region with the frontal
boundary as well...with precip water values returning to levels of 2
to 2.25 inches. Combined with forcing aloft as mid level heights
begin to buckle in response to the approaching upper trough...rain
and storms are likely to become widespread once again tonight across
the forecast area. Could see stronger storms with potential for
gusty winds but the primary threat will be torrential rainfall and
localized flooding.
There should be a lull in convective coverage Saturday morning...but
the arrival and passage of the cold front Saturday afternoon ahead
of the upper trough may initiate a new round of storms along the
front. At this point...the eastern half of the forecast area stands
the best chance to see additional storms with the potential for
convection to be more intense as they track into Ohio where the
atmosphere is likely to be more unstable. With the front shifting
east of the area by late afternoon...should see a dry and noticeably
less humid end to the day Saturday.
The second half of the weekend looks spectacular as high pressure
takes over in the wake of the departing cold front. Skies will clear
quickly Saturday night and remain mostly clear through the rest of
the short term as deep subsidence and increasingly drier air advects
into central Indiana.
Temps...low level thermals largely supported a model blend for temps
through the period. Highs will slip back into the mid and upper 70s
on Sunday while lows by Saturday and Sunday nights will be in the
lower to mid 50s. A much more refreshing and comfortable airmass
for the region for the second half of the weekend.
&&
.LONG TERM /Monday through next Thursday/...
Issued at 222 AM EDT Fri Sep 9 2016
Ensembles in good agreement with the main weather pattern during
this period. Subtropical ridging expected across the southern
parts of the country, with the westerlies located along the
Canadian border.
Main weather maker during this period will be a short wave trough
that is expected to drop southeast through the Great Lakes around
next Wednesday. Will keep some chance PoPs in the forecast near
the middle of next week to cover this feature.
&&
.AVIATION /Discussion for the 090900Z KIND TAF Update/...
Issued at 424 AM EDT Fri Sep 9 2016
Satellite and surface reports indicate an area of LIFR conditions due to
fog and low ceilings off to the northwest of the KIND terminal, drifting
southeast. Appears these conditions will move into the KIND terminal
closer to daybreak. Will back off on the timing of these conditions
more towards 091000Z-091100Z.
Previous discussion follows.
Rain has exited the terminals. Partial clearing, recent rains, light
winds and low dew point depressions will lead to widespread IFR/LIFR
conditions due to fog and low ceilings overnight through the mid morning
hours of Friday.
Another short wave is expected to arrive late in the afternoon on Friday.
Forecast soundings become saturated by late afternoon and have introduced
prevailing VFR rain. Instability looks limited...but a rumble of thunder
cannot be ruled out.
&&
.IND Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...JP/JAS
Area Forecast Discussion
National Weather Service Northern Indiana
357 AM EDT FRI SEP 9 2016
.SYNOPSIS...
Issued at 355 AM EDT Fri Sep 9 2016
Areas of fog...dense in many locations...will begin to slowly
dissipate after sunrise. Shower and thunderstorm chances will
return later this afternoon and increase tonight as low pressure
approaches the region. Locally heavy rainfall will be possible
along with an isolated strong thunderstorm. Temperatures will
continue to trend cooler through the weekend with less humid
conditions.
&&
.SHORT TERM...(Today and Tonight)
Issued at 351 AM EDT Fri Sep 9 2016
Numerous issues to deal with in the short term period. Initial
problem is expansion of dense fog early this morning. Most reporting
sites from Knox Indiana to Hillsdale Michigan northward were
reporting zero to one quarter mile VIS at 07z. With weak high
pressure over the area and calm winds along with moist boundary
layer...widespread fog had developed in this region. Issued a dense
fog advisory for the morning. Upstream cirrus blow off from MO
convection as well as some stratus over IL may help offset further
expansion but a lot of uncertainty as usual with dense fog. Will be
monitoring conditions for any necessary changes to advisory.
Focus then shifts to chances for rain later this afternoon and
tonight. Models have come into a little better agreement with slower
arrival of pcpn...mainly after 00z. A few models do show initial
onset in the far southwest late this afternoon as residual activity
from early morning upstream MCS dissipates and drifts into the area.
Possible MCV from this convection may spark additional development
this afternoon. Will ramp up pops but a little slower than previous
forecasts. Main precipitation event expected tonight into Saturday
as nose of 30-40 kt low level jet moves into the area coincident
with mid level short wave and 2" PWAT axis within Theta-E ridge.
Latest RUC runs picking up on this with expansion of pcpn after 00z
from southwest to northeast. Locally heavy rain remains a concern
but main northern stream short wave now a bit slower and less
phasing with remnant tropical moisture surge as previous model runs
were hinting out. Warm rain processes still expected to dominate
with efficient rain rates. A great example of this occurred Thursday
morning with a few areas picking up 1 to 3 inches of rainfall in
about 3 to 4 hours. Severe risk remains marginal with deep layer
shear increasing to 30-40 knots but instability likely lacking given
overnight timing.
&&
.LONG TERM...(Saturday through Thursday)
Issued at 351 AM EDT Fri Sep 9 2016
Main northern stream trough to move through the region Saturday.
Will likely see rain ending during the morning from west to east
as cold front sweeps east. Secondary boundary still expected in
afternoon and could spark some additional showers with residual
moisture.
Large area of high pressure will drift across the area and provide
dry and comfortable weather from Sunday through Monday night. Next
northern stream short wave and associated surface front to cross the
region Tuesday and Tuesday night. This will bring the chance for
rain back into the forecast. This will be followed by another high
moving across the Great Lakes with reinforced cool and dry Canadian
air.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 213 AM EDT Fri Sep 9 2016
A diffuse front was over the area with drier air to the northwest
over northeast Illinois. However, the flow was too weak to allow
the drier air to spread into northern Indiana. At midnight, areas
of fog with areas of dense fog has already developed across
northwest Indiana where skies had cleared. Really nothing to mix
out the fog until after daybreak. Have adjusted the SBN TAF with
VSBYs 1/4 to 1/2 miles the rest of the night. Conditional
climatology favors conditions clearing by 15Z. May be too
optimistic with VFR by 13Z. Otherwise, storm chances should
increase later this afternoon as a system approaches from the
southwest.
&&
.IWX Watches/Warnings/Advisories...
IN...Dense Fog Advisory until 9 AM EDT /8 AM CDT/ this morning for
INZ003>009-012-014-016.
MI...Dense Fog Advisory until 9 AM EDT this morning for MIZ077>081.
OH...Dense Fog Advisory until 9 AM EDT this morning for OHZ001.
LM...NONE.
&&
$$
SYNOPSIS...Lashley
SHORT TERM...Lashley
LONG TERM...Lashley
AVIATION...Skipper
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Area Forecast Discussion
National Weather Service Saint Louis MO
345 AM CDT FRI SEP 9 2016
.SHORT TERM... (Through Late This Afternoon)
Issued at 345 AM CDT Fri Sep 9 2016
A band of thunderstorms containing heavy rainfall extended from MYJ
southeast through SUS to SAR. Some of these storms were producing
rainfall rates as high as 1-2 inches per hour. More complexes of
storms across portions of western MO and eastern KS will move
eastward through much of our forecast area for the rest of the
morning per the latest HRRR model runs. With the recent rainfall
amounts from Thursday will issue a Flash Flood Watch for parts of
central MO into southwest IL along the I-70 corridor and including
COU, JEF, and the St Louis metro area until early Saturday morning.
Most of the current shower/storm activity should shift east of our
forecast area by noon, although could not rule out isolated to
scattered storms redeveloping along outflow boundaries from morning
convection this afternoon. Should see enough partial clearing this
afternoon that high temperatures will be slightly warmer than
yesterday, and at or a tad above seasonal normals.
GKS
.LONG TERM... (Tonight through Thursday)
Issued at 345 AM CDT Fri Sep 9 2016
(Tonight)
Another round of TSRA expected to be either ongoing or develop
shortly into the evening hours as an approaching cold front, strong
mid level shortwave, and persistent rich moisture thru the column
interact to produce what should be a widespread rainfall for the
area. The most vulnerable areas that can be ascertained for now
will be locations that have already received heavy rainfall, namely
central MO into parts of east-central MO. Will issue a Flash Flood
Watch thru 12z/Sat to highlight heigtened flash flood threat given
expected high rainfall rates in any TSRA and should not take as much
as areas outside of FFA for flooding.
(Saturday - Monday)
Northwest flow aloft and high pressure at the surface should equate
to a quiet wx period here. Initially temps are expected to be below
average, but with southerly flow by late Sunday into Monday, temps
should rise back to above average levels by Monday.
GFS already develops rain chances by late Monday northwest of STL
metro, but prefer slower onset from EC.
(Tuesday - Thursday)
Rain chances should return by Tuesday with a cold front dropping
thru, with cooler air for Wednesday and Thursday with a 1028mb high
pressure settling over the Great Lakes.
TES
&&
.AVIATION... (For the 06z TAFs through 06z Friday Night)
Issued at 1127 PM CDT Thu Sep 8 2016
Period of clearing this evening resulted in formation of local
IFR ceilings and visibilities at KCPS and KSUS in fog. This will
likley improve over the next several hours as next batch of rain
and scattered thunderstorms moves in. Most instability is located
south of KCOU to KSTL line so still think most lightning will stay
south of there however will stick with VCTS to cover possibility
of some mostly in cloud lightning. Precip should end from west to
east towards dawn with ceilings improving to VFR.
SPECIFICS FOR KSTL: VFR conditions should last until around 09Z
when next batch of rain and isolated thunderstorms moves in
producing MVFR ceilings and visibilities. Most lightning should
remain south of KSTL where greater instability is
located...however some in cloud lightning is possible. Rain
should clear KSTL by around 14Z with VFR ceilings returning.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flash Flood Watch through Saturday morning for Audrain MO-Boone
MO-Callaway MO-Cole MO-Franklin MO-Gasconade MO-Jefferson
MO-Lincoln MO-Moniteau MO-Montgomery MO-Osage MO-Saint
Charles MO-Saint Louis City MO-Saint Louis MO-Warren MO.
IL...Flash Flood Watch through Saturday morning for Madison IL-Monroe
IL-Randolph IL-Saint Clair IL.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
423 AM CDT FRI SEP 9 2016
.DISCUSSION...
Currently...Broad upper level ridge of high pressure covers the
southern U.S. and skies are clear across the area. Drier air
continues to reside over eastern parts of the Mid-South where
dewpoints are in the mid and upper 60s. Meanwhile higher
dewpoints, in the lower to mid 70s, stretch from along the
Mississippi River west into Arkansas. As a result temps this
morning are coolest across Northeast Mississippi and the TN River
valley and warmest over the Delta.
Today...Once more warm day on tap across the Mid-South with plenty
of humidity in the Delta region where heat index values will top
100 degrees. Lower dewpoints across the east will keep heat index
values in check there. Like yesterday the HRRR is indicating
isolated development along an axis from Clarksdale-Memphis-
Jackson. This is along the boundary between the moist air to the
west and dry air to the east. Seems reasonable that a few showers
or thunderstorms could occur in this region again this afternoon
so added a 20 pop there. Otherwise expect plenty of CU where
dewpoints are in the 70s with more sunshine toward Northeast
Mississippi. Highs will generally be in the lower 90s.
Tonight and Saturday...A potent upper trof will push into the
Upper Mississippi Valley by Saturday driving a cold front south.
Chances for showers and thunderstorms will move south into the
area later tonight and spread across the entire area on Saturday.
There is some marginal instability to work with but the best shear
remains to the north so the severe threat appears minimal at this
time. Clouds and precipitation will keep temps mainly in the 80s.
Saturday night through Monday...Cool high pressure will build into
the area with a much drier airmass. Dewpoints will drop into the
upper 50s with temps in the 80s on Sunday. Temps will warm a few
degrees on Monday but dry airmass will remain over the area.
Tuesday through Thursday...Upper ridge reestablishes itself over
the region and temps will climb back slightly above normal. A
decaying cold front moving into the area may produce a few showers
and thunderstorms during the Wednesday/Thursday time frame.
SJM
&&
.AVIATION...
06Z Tafs
Mainly VFR conditions are expected over the 24 hour TAF period
with the possibility of MVFR categories overnight at KMKL due to
patchy fog. Gusty winds from the south tonight at KMEM should soon
subside, however they will increase again during the day tomorrow.
WInds areawide will be from the south tomorrow at near 10KTs, some
locations will see gusts up to 15KTs.
JPM3
&&
.MEG Watches/Warnings/Advisories...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Marquette MI
500 AM EDT FRI SEP 9 2016
.SHORT TERM...(Today and tonight)
Issued at 444 AM EDT FRI SEP 9 2016
00Z raobs/latest wv imagery and RAP analysis show a WSW flow aloft
btwn lo amplitude troffing over the Wrn Plains and an upr rdg over
the SE Conus. At the sfc, a weak hi pres rdg over WI/very dry airmass
depicted on the 00Z GRB raob /pwat 0.59 inch/ are bringing quiet wx
to the cwa. With lighter winds at the sheltered interior spots,
temps have fallen into the 40s at the cooler spots. But some mid clds
are aprchg fm the SW ahead of a shrtwv tracking ENEwd toward MN under
the WSW flow alf E of the Rockies trof. Some showers have also popped
up as far E as Ecentral MN/NW WI in the WAA pattern/deep lyr qvector
cnvgc ahead of this shrtwv. But dry llvl air depicted on the 00Z MPX
raob is restricting the coverage of these showers. More nmrs showers/
TS are present moving thru Scentral MN into Wi. Another stronger
shrtwv digging into the trof to the W is over the Nrn Rockies.
Main fcst concerns in the short term focus on timing/coverage of
pcpn associated with upstream shrtwvs moving thru the Plains trof.
Today...Although sct-bkn mid clds aprchg the SW border wl overspread
Upr MI this mrng, suspect the showers now moving into NW WI wl dspt
as they move into drier air and farther ahead of area of sharper
forcing ahead of shrtwv in SW MN per the latest HRRR fcst. But by
early-mid aftn, some of the sharper forcing/incrsg h85 theta-e advctn
ahead of this disturbance is fcst to influence the cwa. Although the
dryness of the llvls may tend to slow the spread of the showers and
limit their coverage, wl retain the flavor of the previous fcst and
show incrsg pops fm the SW. Although the incoming clds wl limit
insolation, fcst h85 temps arnd 14C wl still allow temps to rise well
into the 70s, especially away fm Lk MI moderation. With a
downsloping SW wind, temps near Lk Sup wl aprch 80.
Tngt...As stronger second shrtwv/accompanying dpva/deep lyr qvector
cnvgc/upr dvgc aprch fm the SW tngt, expect pcpn coverage and
intensity to increase. Overall, model qpf indicates the heavier rain
wl impact the Ecentral cwa under axis of some sharper mid lvl fgen/
deformation zn. Fcst wl thus show the hier categorical pops in this
area. As a sfc lo begins to intensify over Nrn Lk MI late, some
stronger N winds may dvlp over toward 12z over the W.
.LONG TERM...(Saturday through Thursday)
Issued at 458 AM EDT FRI SEP 9 2016
Models suggest that a progressive pattern will prevail through the
middle of next week. A mid/upper level trough moving through the
western Great Lakes Saturday will give way to ridging Sunday.
Another trough will move from the nrn plains to the nrn Great Lakes
from Monday into Tuesday will bring a cold front through the region
with much cooler air moving in Tuesday into Wednesday.
Saturday, Although the models have converged, the ECMWF remains
slightly stronger/slow compared to the GFS. A band of heavier pcpn
associated with stronger mid level fgen/deformation is likely to be
ongoing at 12z Sat into cntrl and/or east cntrl Upper Michigan.
MUCAPE values will support some embedded tsra that may linger over
the ern cwa in the morning. Breezy nw to n winds and 850 mb temps to
around 6C with the mid level trough and deep moisture over the area
will also support additional lake enhanced rain over the west near
IWD early and over n cntrl Upper Michigan into the afternoon.
Saturday night and Sunday, mid level and surface riding will quickly
build into the region Saturday night with clearing skies and
diminishing winds allowing temps to drop into the lower 40s inland
and the lower to mid 50s near the Great Lakes. Mostly sunny skies and
temps near normal around 70 should prevail Sunday as the high builds
toward the ern Great Lakes.
Monday-Wednesday, the GFS/GEFS and ECMWF were in better agreement
with the timing of the next mid level trough affecting the area late
Monday into Tuesday. A front will drop through the nrn lakes Monday
night that will provide a focus for shra/tsra chances. Models
suggest that 850 mb temps dropping into the 0C to 4C range behind the
front will bring more Fall-like conditions with highs in the lower
60s or possibly lower. Some light lake effect rain showers may also
be possible Tuesday even with the relatively dry airmass.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 138 AM EDT FRI SEP 9 2016
Dry air at the low levels will linger thru at least the first half
of this fcst period, resulting in VFR conditions prevailing at
KIWD/KCMX/KSAW. However, some patchy shallow radiation fog may
affect KIWD and perhaps KSAW overnight under clear skies/calm wind.
An approaching cold front and low pres system may begin to spread
-shra into Upper MI this aftn, but more so this evening, especially
at KSAW. Right now, it appears it will be just after this fcst
period that prevailing conditions fall blo VFR.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 444 AM EDT FRI SEP 9 2016
Plan on SSW winds up to 20 kts into tonight between departing
surface hi pres and an approaching cold front. The front will pass
Lake Superior late tonight into Sat as a rapidly deepening lo pres
moves from Wisconsin into SE Canada. N to NW winds up to 30 kts will
develop in the wake of this passing lo pres, and at least some
marginal gales are not out of the question especially over the E
half of the lake. As trailing hi pres follows into the Upper Lakes,
expect the winds to diminish steadily Sat night into Sun. But SW
winds will pick up to 25 to 30 kts on Sun night into Mon as the
hi shifts to the E and another cold front approaches from the NW.
Following the passage of this front later on Mon, there will be
another wind shift to the NNW up to 20 kts.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...KC
LONG TERM...JLB
AVIATION...Rolfson
MARINE...KC
Area Forecast Discussion
National Weather Service Nashville TN
239 AM CDT FRI SEP 9 2016
.DISCUSSION...
Status quo today with highs mainly upper 80s to low 90s under
sunny to partly cloudy skies. Like yesterday, a brief shower or
thunderstorm cannot be ruled out over our northwest counties. The
upper level ridge responsible for this pattern will finally back
off as a trough sweeps across the Great Lakes and Ohio Valley
during the next 48 hours. The trough will drive a cold front
through Mid Tennessee Saturday evening. The probability for
showers and thunderstorms will increase Saturday afternoon and
evening with the approach of the front. Rainfall amounts do not
look impressive overall, but a few spots could pick up some brief
downpours. There will be enough instability and mid level wind
energy for the possibility of a few strong storms with gusty
winds, mainly over the north half of the area.
Dry high pressure will move for Sunday through Monday.
Temperatures will be cooler, and Humidity levels will be
significantly lower. Monday morning will actually feel chilly with
lows in the 50s. Sunshine will keep the days seasonably warm with
highs in the 80s, but the low humidity will make it feel quite
pleasant, especially compared to recent humid conditions.
Looking ahead, warmth and humidity will climb above normal again
after Monday. A weak front will dip into the region midweek with
a slight chance for showers or storms. It may also help keep the
above normal heat and humidity from getting quite as high as we
have experienced this week.
&&
.AVIATION...
06Z TAF DISCUSSION.
VFR conditions expected at all airports through the TAF period.
HRRR model indicates additional showers will pass near CKV around
sunrise Friday morning, so have added VCSH to CKV TAF for a few
hours. No visibility restrictions due to fog expected tonight due
to LLJ around 20 knots. Southwest winds up to 10 knots anticipated
at terminals through the TAF period.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 93 71 90 63 83 / 10 10 50 30 0
Clarksville 90 72 86 59 80 / 20 20 60 20 0
Crossville 88 66 86 62 79 / 10 10 30 40 0
Columbia 92 69 89 62 83 / 10 10 40 40 0
Lawrenceburg 92 68 89 63 83 / 10 0 40 30 0
Waverly 90 71 86 60 80 / 10 10 60 20 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......13
AVIATION........Shamburger
Area Forecast Discussion
National Weather Service New York NY
552 AM EDT FRI SEP 9 2016
.SYNOPSIS...
A cold front stalls over the area today. The front will
lift north as a warm front late tonight and Saturday. A cold
front moves through on Sunday, followed by high pressure building
in early next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Any morning fog will burn off by mid morning.
There is general model agreement in stalling the cold front right
over the area. Exact placement will make a difference in wind
forecast, temperature forecast, and expected humidity levels.
A warm to hot day is expected regardless.
Leaned toward latest WRF-ARW, WRF-NMM for wind forecasts, with
seabreezes developing, especially in and around NYC, Long Island
and Southern CT.
After a very warm start, expect temperatures to rise well into the
80s, and perhaps 90s in a few spots. A MOS blend followed. Clouds
may inhibit higher readings, but several factors are in play and
trends need to be monitored.
As for sensible weather, ridge aloft builds, with mid level lift
noted in tracking vorticity maxima through the day. Any weak lift
in combination with sfc boundary, cold front, could trigger
isolated showers and thunderstorms. Latest HRRR and analysis of
SBU NAM and GFS WRF model runs show sparse coverage today. Kept
POPs rather low, in spite of higher MOS numbers.
There is a moderate risk for rip current development today due to
a combination of 2 ft long period se swells and 3 ft southerly
wind waves.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Flow aloft amplifies as upstream trough digs across the upper mid
west, traversing across the Great Lakes Region during this time
frame. As a result, ridge along the eastern seaboard builds
further.
At the surface, stalled front nearby tonight will lift north
Saturday. Once again, front could act as a trigger, but do not see
much forcing aloft for anything other than isolated to scattered
showers/thunderstorms through this period. Better chance for more
widespread precip remains well to the west ahead of the
approaching trough.
Warm temperatures continue, with lows tonight ranging from the
upper 60s to the mid 70s under plenty of clouds.
On Saturday, temperatures should rise well into the 80s,
especially away from the water as south flow keeps eastern
locations cooler. Away from the water, some 90 degree readings are
likely.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A cold front approaches and is progged to reach the lower Hudson
Valley by daybreak Sunday before moving offshore by late afternoon.
Looks like the best overall chances of a shower or thunderstorm will
be during Sunday morning. PoPs are still capped at chance for the
time being. Clouds diminish Sunday afternoon and it turns somewhat
breezy with cold air advection aloft. Thinking is that this CAA will
be delayed enough to allow high temperatures reach the mid 80s in
and around the city as well as a good portion of Long Island.
High pressure builds in for Monday with a cooler and drier air mass.
It should be a sunny day with high temperatures near normal. Dry and
sunny conditions continue for Tuesday, and with high pressure
offshore, a return southerly wind flow will bring warmer high
temperatures and a rise in dewpoints.
A cold front is then forecast to move through some point during
Wednesday with a chance of a shower or thunderstorm. High pressure
returns for Thursday with noticeably cooler and drier conditions.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
A cold front slowly drifts south across the region today.
Patchy IFR this morning, mainly across Connecticut and Long
Island. All areas predominantly VFR today, with perhaps some MVFR
or lower in any showers and thunderstorms that develop. The best
chance for precipitation will be roughly 21-03Z, but coverage and
timing is too uncertain to include in the TAFs at this time.
Light and variable winds across Long Island and Connecticut this
morning, with a light westerly flow elsewhere. Winds veer to the
west northwest all areas today. Sea breezes are expected along the
immediate coasts, then all flow becomes light and variable
tonight.
NY Metro Enhanced Aviation Weather Support...
Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90
KJFK TAF Comments: Winds may remain near 210 true through 11-12Z.
KLGA TAF Comments: Occasional gusts to around 15 kt are possible
this morning.
KEWR TAF Comments: Occasional gusts to around 15 kt are possible
this morning.
The afternoon KEWR haze potential forecast is GREEN...which implies
slant range visibility 7SM or greater outside of cloud.
KTEB TAF Comments: Occasional gusts to around 15 kt are possible
this morning.
KHPN TAF Comments: Winds may be variable at times through 12Z.
KISP TAF Comments: Amendments will be possible if IFR develops
into the area.
.Outlook for 06Z Saturday through Tuesday...
.Fri Night...low chance of showers and thunderstorms with a warm
frontal approach. MVFR or lower possible.
.Sat...Mainly VFR.
.Sat Ngt...MVFR with showers and isolated thunderstorms.
.Sun-Tue...VFR. Northwest gusts around 20 kt on Sunday.
&&
.MARINE...
A cold front stalls over the waters today and tonight. As such.
winds should remain relatively light, with speeds in the teens in
spots due to sea breeze enhancements during the day.
Winds diminish tonight, but will increase from the south Saturday
as the front lifts to the north. The pressure gradient will
tighten Saturday, so expect a steady increase in wind speeds
Saturday afternoon.
Seas remain under 5 Ft over the ocean waters today and tonight,
and 2 ft or less for the non ocean waters. By Saturday, expect
seas to build as the winds increase.
The pressure gradient tightens over the area waters Saturday night
with the approach of a cold front. Expect an increase in winds and
seas during this period. Looks like SCA conds are likely at least on
the ocean waters, and gusts to 25 kt for some of the other waters
could be possible. The cold front moves through on Sunday, and
between the pressure gradient and some cold advection, SCA conds
should continue on the ocean waters with marginal conditions on the
other waters.
Winds and seas then subside Sunday night with conditions below
advisory criteria prevailing through the rest of the forecast
period.
&&
.HYDROLOGY...
Moderate to severe drought conditions continue for Suffolk County.
Please refer to the latest local drought statement for details.
No widespread significant rainfall expected through early next
week.
&&
.CLIMATE...
With warm air returning to the region today, there is a chance
record highs could be tied or broken.
The following are the record and forecast highs for
today September 9
RECORD HIGH FORECAST HIGHS
EWR....94/1964.........92
BDR....89/1959.........89
NYC....94/1915.........89
LGA....91/2002*........90
JFK....93/1959.........88
ISP....89/1996.........88
* RECORD ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...JC
AVIATION...JMC
MARINE...JC/PW
HYDROLOGY...JC/PW
CLIMATE...
Area Forecast Discussion
National Weather Service Paducah KY
314 AM CDT FRI SEP 9 2016
.SHORT TERM...(Today through Sunday)
Issued at 314 AM CDT Fri Sep 9 2016
Timing and coverage of showers and thunderstorms will be the main
concern through Saturday. There has been no significant change in
the models over the past 24 hours. There is still a strong model
consensus that the greatest precip coverage will remain along and
northwest of the Ohio River through tonight. On Saturday, the
highest precip coverage will shift southeastward across western
Kentucky with a cold front.
As far as the details for today, a low-level boundary has become
established from around kmdh southeast across the Pennyrile region
of west KY. This is primarily evident in 07z 925 mb vad wind
profiler plots, which showed northwest winds at kstl and kvwx
(Evansville) and southwest winds at kpah. Scattered thunderstorms
have been developing along this boundary overnight. The hrrr and
00z nam are handling this precip area fairly well.
During this morning, the nam/gfs develop a surface warm front in
the same approximate location as the 925 mb front. The front then
lifts northeast across southwest Indiana during the midday hours.
Most of the models are in agreement that precip will generally
decrease or end as the warm front exits our region this afternoon.
However, the air mass behind the front will be very moist and
unstable this afternoon. The southern fringe of stronger 500 mb
flow will be over southern IL and southwest IN. Diurnally-driven
redevelopment of scattered convection is possible after 18z. A few
storms could be marginally severe, primarily in the stronger deep-
layer shear up toward the Interstate 64 corridor. Shear parameters
are not impressive, with 0-6 km shear values only around 25 knots
in southern IL and southwest IN.
After the diurnally enhanced convection diminishes this evening,
attention turns toward a cold front approaching our western
counties after midnight. Although this front will be well-defined
and the associated 500 mb shortwave will be strong, the models are
rather skimpy with qpf near the front late tonight and Saturday
morning. However, the models ramp up qpf along the front as it
crosses the Pennyrile region of western Kentucky Saturday, likely
influenced by diurnal heating and destabilization. It still
appears the frontal timing will be early enough in the day to
preclude an organized severe threat, however the Pennyrile region
of western Kentucky will need to be monitored.
A strong influx of cooler and much drier air will follow the front
for Saturday night and Sunday. This air mass will be similar to
last Friday`s, when 850 mb temps were around 12C and surface highs
were in the upper 70s to near 80. The column will be very dry, and
nothing more than a few cumulus clouds are expected.
.LONG TERM...(Sunday night through Thursday)
Issued at 314 AM CDT Fri Sep 9 2016
Forecast confidence is high through Tuesday, but decreases through
the end of the week.
The 00Z models are in pretty good agreement in keeping our area
along the northern fringe of high pressure aloft through the period.
We will start out with dry surface high pressure in control, but it
will be weakening with time. An upper-level storm system will push
eastward through the Great Lakes Tuesday night and Wednesday, and
this will bring a cold front of sorts through the region on
Wednesday.
As the surface high weakens, it really prevents the winds from
turning around to the south ahead of the cold front. Therefore, we
may just have a surge of surface high pressure coming through the
area on Wednesday rather than a convergent boundary, capable of
focusing convection. We will continue with some low chance PoPs
mainly in the northwest on Wednesday just in case some convection
makes it into the area before the adverse low-level wind field kills
it off.
Some of the 00Z models still try to develop some light QPF behind
the "front" later Wednesday through Thursday, but the 00Z ECMWF has
come in almost completely dry through Thursday. The ECMWF is likely
on the right track, but will have to keep some small PoPs mainly
south and west Wednesday night and Thursday, just to fit in
with surrounding forecast areas.
There are considerable differences between the 00Z GFS and ECMWF in
the handling of energy over the inter-mountain west, which will have
an impact on the sensible weather in our region heading into Friday.
The 00Z GFS has a closed low and pumps up a ridge over or just west
of our region, which should keep us high and dry. The 12Z ECMWF has
a more progressive scenario which shunts the ridge to our southeast,
and allows for some convective potential especially over southeast
Missouri and southern Illinois. Do not have a good feeling either
way at this point, but figure there will be at least some low chance
PoPs over the area for next Friday.
Temperatures will start out a bit cooler than normal with some areas
maybe into the lower 50s Monday morning. A modest warming trend up
to near normal levels is forecast through Tuesday. Wednesday will be
normal as well and then temperatures will trend a bit cooler for
late week.
&&
.AVIATION...
Issued at 314 AM CDT Fri Sep 9 2016
A line of convection developed overnight along an elevated warm
front from near kmdh to kowb. These storms will continue to
increase in coverage and move ENE. A tempo group for tsra may soon
be needed for the KEVV and KOWB taf sites. Otherwise mainly VFR
conditions will continue. Some mvfr vsbys are possible around
sunrise at kcgi/kpah, but confidence is low. There could be
development of isolated storms again this afternoon and early this
evening, mainly in the kevv/kowb area. A prob30 group for tsra is
in those tafs. Winds will be from the south to southwest,
increasing to 5 to 10 knots in the afternoon.
&&
.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...MY
LONG TERM...DRS
AVIATION...MY
Area Forecast Discussion
National Weather Service La Crosse WI
644 AM CDT FRI SEP 9 2016
.SHORT TERM...(Today through Monday)
Issued at 309 AM CDT Fri Sep 9 2016
Sheesh....more rain? Seems like we can`t catch a break in the
rainfall department lately, with the next 24-36 hours expected to
bring at least one if not a couple of additional rounds of showers
and storms, with at least a small risk for some to be on the
stronger side. The early morning pattern looks an awful lot like it
should this time of year, featuring a rather broad upper trough
digging through the northern Rockies with several embedded stronger
shortwaves. One such lead wave is currently working through southern
South Dakota and helping touch off a smattering of convection, with
another in tow across northern Wyoming and a third, much stronger
primary upper wave streaming into northeast Montana. Closer to home,
quite the dry airmass intact across much of our area at the moment,
but that quickly changes just to the south with a notable surge of
deeper 850-800mb moisture working back north through northeast
Nebraska and into northwest Iowa, quickly headed here through the
morning hours on the nose of a modest low level jet.
As such, see no real reason why current convection upstream won`t
upscale through at least mid morning, with effective shear on the
order of 40+ knots supportive of supercellular characteristics with
mainly a hail threat given the elevated nature of convection (have
seen some of this to our west overnight). In addition, given a quick
increase in warm cloud depth to around 3.5-4km once again with PWATs
climbing toward 1.5 inches, have to again worry about some heavy
rain potential, especially if organized storms can lay out along the
northward advancing warm front, though given much better upper
dynamic forcing from the lead wave, would think convection will tend
to be more progressive than recent days. However, the simple fact is
we just can`t take much more water across northeast IA/southwest WI
where 1 hour flash flood guidance is only around a meager inch or
so.
After round 1, we will likely see things spit and sputter into the
afternoon with the approach of wave number 2, though the degree of
available instability remains somewhat in question pending how much
sunshine we can manage. Have a feeling we may break out enough into
the afternoon in advance of the third incoming stronger wave/cold
front to achieve some modest instability in the presence of still
rather impressive shear. Interesting to see recent runs of the HRRR
trying to sneak a frontal wave right through the region, with the
conceptual pattern ripe for supercell development right along the
cold front. Given the potential for some backed flow should that
surface wave actually occur, do have at least a little concern we
may be setting up for a sneaky localized tornado environment across
particularly northeast Iowa, though rather paltry 0-1km shear will
preclude a specific mention at this point, with large hail/damaging
winds from supercellular structures right along the front the main
concern.
Thankfully, not much else to discuss thereafter, with the passage of
the cold front ending our convective chances through the late
evening. Stronger low/mid level cyclonic flow working into the
region coincident with quite the push of cold advection will likely
act to keep at least chances for some "wrap around" showers going
for north and east areas into the day on Saturday, before strong
drying and expansive low level ridging working through the area
bring in another shot of early fall weather with seasonable temps
and pretty much no threat for rain.
.LONG TERM...(Monday Night through Thursday)
Issued at 309 AM CDT Fri Sep 9 2016
The classic September roller coaster type of pattern looks to
continue through late week, with high pressure working east of the
area and helping set up better return flow across the region by
Tuesday, just in time for our next cold front to arrive. Will have
some chance for showers and maybe a little thunder with that
feature, before our next surge of even cooler air arrives into mid
and late week along with high pressure and more much-needed dry
weather.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 644 AM CDT Fri Sep 9 2016
Main taf forecast concern is convection possibilities and MVFR
conditions at both the RST/LSE taf sites through the taf period. A
warm front lifting north this morning will be the focus for showers
and thunderstorms at both RST/LSE taf sites through the mid to late
morning hours. This first line of convection should move through the
RST/LSE taf sites by 16z today. There should be break between the
next round of convection...which is in association with a low
pressure system moving over Lake Michigan this evening. Expect
another round of scattered shower/thunderstorm activity to move
across the region and possibly impact the RST/LSE taf sites this
afternoon into the evening hours. With the convection this
morning/this afternoon and into the evening hours expect MVFR
ceiling/visibilities conditions.
&&
.HYDROLOGY...
Issued at 309 AM CDT Fri Sep 9 2016
Minor flooding continues along the Kickapoo River but with water
levels now falling north of Gays Mills while some flooding also
continues across portions of Richland County along the Pine River.
Heading into today and this evening, continue to have concern about
one or two rounds of additional showers and storms moving through
the region. From a pattern perspective, the setup is not nearly as
good as in recent days for widespread heavy rainfall with batches of
storms expected to move along at a decent speed, though any repeated
rounds of storms could put down some isolated 2-3 inch amounts.
Given how low flash flood guidance remains across mainly northeast
Iowa into parts of southwest Wisconsin with very wet soils, there is
some risk for flooding depending on the evolution of convection the
next 24 hours, though confidence at the moment is just not there as
of yet to issue any type of Flood Watch. Thankfully, after this
batch of precipitation, dry weather will make a return into early
next week, with only smaller chances for some more showers toward
Tuesday of next week.
&&
.ARX Watches/Warnings/Advisories...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Lawrence
LONG TERM...Lawrence
AVIATION...DTJ
HYDROLOGY...Lawrence
Area Forecast Discussion
National Weather Service Bismarck ND
838 AM CDT Fri Sep 9 2016
.UPDATE...
Issued at 838 AM CDT Fri Sep 9 2016
Leading edge of the cold front based upon the 925-850mb thermal
packing and surface observations places it from near Beach to
Garrison and east into Harvey. This front will continue pressing
southeast this morning, through Bismarck by 11am cdt. Latest
fog/stratus loop and HRRR ceiling forecast pushes an area of low
clouds behind the front from northwest to southeast this morning
into the afternoon. Local/regional radar also shows scattered
showers behind the front, currently favoring northwest and north
central ND. Previous forecast with mostly cloudy, breezy, scattered
showers and an isolated thunderstorm remains on track for today.
UPDATE Issued at 633 AM CDT Fri Sep 9 2016
No changes required with this update other than to blend to
observed trends through 11 UTC as the surface cold front will soon
be passing through the US Highway 2 corridor.
&&
.SHORT TERM...(Today and tonight)
Issued at 327 AM CDT Fri Sep 9 2016
Cooler temperatures with scattered rain showers and isolated
thunderstorms highlight the short term forecast for today.
As of 08 UTC, a cold front near the international border will
continue to propagate southeast across western and central North
Dakota this morning. Temperatures in the lower to mid 60s are
expected area today. Scattered rain showers focused behind the
front this morning will increase in coverage with daytime heating
and cool temperatures aloft with the upper level low. A few
thunderstorms may also be possible. Given good agreement, a
consensus of the 00-06 UTC global and hi-resolution suites were
used for most fields.
.LONG TERM...(Saturday through Thursday)
Issued at 327 AM CDT Fri Sep 9 2016
A warm up into Sunday, followed by cooler temperatures Monday and
Tuesday highlight the extended forecast.
Shortwave ridging is forecast to build across the Northern Plains
on the 00 UTC global suites Saturday into Sunday. A possible
return to highs in the 70s and 80s are forecast on Sunday. A
strong cold front continues to be favored to move across the
region on Monday, with cool high pressure potentially remaining in
place on Tuesday. Much cooler highs with temperatures in the 50s
and 60s are forecast Monday and Tuesday. Frost could be possible
Monday night and into Tuesday morning
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 633 AM CDT Fri Sep 9 2016
MVFR stratus will spread across western and central North Dakota
this morning from northwest to southeast behind a cold front.
Scattered showers and isolated thunderstorms are forecast across
the area today. The greatest coverage is expected to be this
afternoon with peak daytime heating.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...PJA
LONG TERM...PJA
AVIATION...AYD
Area Forecast Discussion
National Weather Service Billings MT
920 AM MDT FRI SEP 9 2016
.UPDATE...
Cyclonic NW flow aloft exists over the region this morning with a
healthy 100kt H3 jet nosing thru western MT. 12z raobs measured a
cold pool of -21c at 500mb at TFX/GGW. Combination of weak ascent
with modest instability will yield scattered showers and a few
thunderstorms today, with best chance of lightning east of
Billings where lifted indices will approach -1c. Small hail is
possible given the lower freezing levels, but otherwise the
convection today will be benign. Western areas will begin to
transition to anticyclonic flow aloft and warming mid level temps
this afternoon, so expect an eastward shift in the shower coverage
by mid to late afternoon. Could see a few showers linger near the
Dakotas border until around sunset. Tonight will be dry otherwise
as ridge builds from the west and becomes established over the
region. Temps today will be cooler than Thursday with highs in the
60s, along with a breezy/mixed NW wind with gusts 20-30 mph. JKL
&&
.SHORT TERM...valid for Tdy and Sat...
RAP 300 MB analysis shows 90-100 kt jet streak extending from
western Idaho through central Wyoming. This favored jet position
is allowing scattered showers to develop from YNP through
southeastern Montana. Isolated showers will be a possibility from
Livingston through Broadus in the early morning hours where
favored frontogenesis and jet support resides as the jet kicks
eastward. A front slides south from Canada bringing scattered
showers with an isolated thunderstorm possible to the eastern half
of the CWA. Cloudy skies begin to clear on Saturday as ridging
builds in from the west. Low-level westerly flow will aid
downsloping, brining warmer and drier conditions to the area.
Expect highs into the low to mid 80s with humidity values around
15 percent with no rain. Walsh
.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...
Extended forecast starts out with zonal westerly flow ahead of
strong Canadian cold front that will arrive Sunday
afternoon/evening. Temperatures Sunday will depend entirely on the
arrival time of the front with some models suggesting a late
morning arrival and others early evening. For now split the
difference with temperatures ranging from the 60s northwest to the
80s southeast. It will take a bit of time for atmosphere to
saturate up but by late evening expect a good chance of
precipitation over the northwest half of the forecast
area...spreading southeast overnight.
Upslope winds deepen up to keep good chances of precipitation
going into Monday evening, especially for mountain/foothill
locations. 700mb temperatures drop to -5c/850mb to +3c by Monday
morning behind the front which should push snow levels down to
about 6500 feet. Expect a dusting of snow in the higher foothills,
with several inches of snow in the mountains, which could impact
the Beartooth Highway and US14 over the Bighorn Mountains. For
lower elevations a cold rain could add up to over a quarter of an
inch over a broad area Sunday night through Monday.
Tuesday into Wednesday sees a dry and warmer forecast as upper
trof shifts east and drags the 1030mb high into the plains.
A chunk of energy from the trof cuts off and drifts southwest
into northern California, then gets kicked back into the northern
Rockies Wednesday night into Friday. GFS ensemble mean and ECMWF
agree on pushing this energy over the area providing another shot
of showers and thunderstorms for the end of the week. Chambers
&&
.AVIATION...
Scattered showers are possible over south central/southeast MT
and north central WY through late afternoon today...with the best
chance east of KBIL and in the Bighorn mountains. Expect mountain
obscurations, IFR conditions in the mountains, and temporary MVFR
conditions in the lower elevations with this activity. Isolated
thunderstorms are possible east of KBIL through late afternoon.
Gusty northwest winds (to 30kts) are expected this morning
especially near any shower activity. Wind speeds are expected to
taper off late this afternoon. Flight conditions will be improved
by mid to late afternoon as shower activity shifts southeast.
RMS/JKL
&&
.PRELIMINARY POINT TEMP/POPS...
Tdy Sat Sun Mon Tue Wed Thu
-------------------------------------------------------
BIL 068 047/081 052/079 044/052 039/063 043/073 050/070
2/W 00/U 01/B 65/W 31/B 12/T 33/T
LVM 067 040/080 045/074 039/049 032/058 038/070 043/071
2/W 00/N 02/T 66/W 31/B 12/T 22/T
HDN 068 043/082 048/080 045/054 040/066 044/076 050/071
2/T 00/U 01/U 54/W 31/B 11/U 33/T
MLS 067 045/081 051/080 046/056 041/066 046/077 052/075
4/T 10/U 00/U 32/W 21/B 11/U 22/T
4BQ 063 043/080 049/082 047/056 041/065 047/077 051/075
3/T 10/U 00/U 23/W 21/B 11/U 22/T
BHK 063 043/077 048/078 047/056 039/063 045/074 051/074
4/T 20/U 00/U 32/W 11/B 11/U 22/T
SHR 064 041/080 047/080 044/050 037/062 042/073 046/070
3/W 00/U 00/U 46/W 42/W 11/U 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Des Moines IA
642 AM CDT Fri Sep 9 2016
.SHORT TERM.../Today/
Issued at 328 AM CDT Fri Sep 9 2016
Main challenges today will be convection and temperatures. First
impressions...models not doing very well early this morning. At
0730z there is little convection over northwest/western Iowa while
most of the hires models suggested that areal coverage of
thunderstorms would be filling into this area by now. Isolated weak
convection has attempted to develop near Denison/Carroll...but it is
having difficulty holding together. Subjective 03z surface shows a
weak stationary front across southern Iowa...tied to a low over
north central Nebraska. Aloft at H850...flow remains weak over most
of Iowa from the south/southwest at 10-15kts while slightly stronger
flow of 10 to 20kts is persisting in Nebraska. There is also a warm
front aloft which is most likely resulting in the convection now
over eastern South Dakota/western MN. The general lack of convection
at 0730z might be tied to the stronger MCS south in Kansas-Missouri.
As a result of the situation...have trimmed back PoP northwest
through 11-12z and gradually increase across north/north central
through 18z...keeping most of south central dry for now. The push of
mainly stratiform precipitation over northern Missouri may affect
the southeast through 18z. A slightly more consistent picture is
expected this afternoon as the cool front/low sweeps east into the
area.
The weak Nebraska surface low will track into Iowa later this
morning keeping the south in the warm sector. Shower and thunder
chances will remain north with generally increasing chances again
northwest to southeast through 00z. The ESRL HRRR...NMM...ARW and
most of the synoptic models agree that the front will begin to light
up during the afternoon. The initial surge of instability along the
boundary over western/southwest Iowa should be the main concern for
severe weather into the mid to late afternoon hours. This area will
have longer to recover and remain undisturbed for most of the day.
Bulk shear is not particularly strong but enough at 25 to 40kt to
support severe weather with wind and hail the main concerns.
Sufficient cape to 1600-2000 J/KG over the west will diminish
quickly into the evening hours though shear increases behind the
boundary. H850 moisture analysis at 00z shows tropical remnants of
Newton now extending from Texas to Nebraska and this will feed into
the front today. Precipitable water forecast is between 1.5 and 1.75
this afternoon. With some focus along the front the potential for a
1 to 2 inch rainfall is possible. We continue outlooked for a slight
risk of excessive rainfall today through evening. Though the risk is
there...it remains more isolated due to the expectation that the
front will push the storms along as it moves east. 1 hour flash
flood guidance is at least 1.5 inches or higher...with 3 hour at
least 1.75 inches or higher. The areas which experienced heavier
rainfall Tuesday through Wednesday evening may experience minor
runoff issues if some of the storms manage to output up to 2
inches/hour. Typical urban runoff is also possible in the metro
areas as well. The storms are progged to affect the I35 corridor
and the Des Moines area by 23-00z...so this line may impact rush
hour traffic later today. For now will not highlight any areas with
headlines given storm movement of 20 to 25kts should offset rainfall
rates. Highs today will recover into the mid 70s north to the lower
80s in central and southern areas.
.LONG TERM.../Tonight through Thursday/
Issued at 328 AM CDT Fri Sep 9 2016
Forecast focus is on lingering storm chances tonight...with drier
and pleasant conditions this weekend into early next week.
Tonight: Forecast Confidence = Medium
An MCS or broken line of storms is expected to be ongoing at the
beginning of the period along a cold front that will bisect Iowa
from NE to SW at 00Z Saturday. The front and associated storms
should remain fairly progressive as they move off to the
east/southeast. The latest CAM guidance from the NSSL WRF, 4KM NAM
NEST, WRF ARW/NMM, and ESRL HRRR indicate that a majority of the
storms should exit the area by 06-09Z Saturday. The primary severe
threat this evening and tonight /conditional on instability/ will
likely be damaging winds, due to linear MCS mode, along with
locally heavy rainfall. Behind the cold front, breezy northwest
winds will advect in a cooler and drier airmass. Lows tonight
should fall into the 50s.
Saturday through Monday: Forecast Confidence = High
Surface high pressure will build into the Midwest in the wake of the
aforementioned cold front which will result in a stretch of
fantastic weather from Saturday through Monday. Could see some
residual cloudiness Saturday morning, otherwise expect Saturday to
be a breezy day with northwest winds of 15 to 25 mph due to a fairly
tight pressure gradient and subsidence in the wake of the upper
shortwave. H8 temps in the 8C to 10C range will keep highs in the
upper 60s and lower 70s. Southerly return flow on the backside of
the surface high will lead to a moderation in temps on Sunday and
Monday with highs in the 70s to lower 80s. Dewpoint values will
generally be in the 50s, very comfortable.
Monday Night through Thursday: Forecast Confidence = Medium/High
The 00z suite of models have slowed the next upper trough and
associated cold front a bit, but is still expected to impact the
area from Monday night into Tuesday, resulting in a chance of
showers/tstms, especially over southern Iowa. In the wake of this
frontal passage, a strong Canadian high pressure system is expected
to move into the region on Wed-Thu with the possibility of some of
the coolest weather of the season thus far. Highs on Tuesday and
Wednesday will likely remain in the 60s with lows in the 40s over
northern Iowa on Tuesday night.
&&
.AVIATION.../For the 12Z TAFS through 12Z Saturday morning/
Issued at 641 AM CDT Fri Sep 9 2016
Main concerns are low cigs/vsby early today over the
region...giving way to sct-bkn MVFR/VFR conditions over the south
by 15-16z. Current IFR conditions across region with line of
storms affecting KMCW and possibly KALO 12-17z...with additional
storms developing northwest/west/southwest by 17-20z. This line
will move southeast through the entire area...KFOD by 00z east to
KMCW/KDSM by 02-03z and KALO/KOTM by 03-04z. Northwest winds will
increase aft 02z as front pushes southeast. /rev
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...REV
LONG TERM...Fowle
AVIATION...REV
Area Forecast Discussion
National Weather Service Grand Forks ND
1013 AM CDT FRI SEP 9 2016
.UPDATE...
Issued at 1011 AM CDT Fri Sep 9 2016
Cold front located near a Warroad-Crookston-Valley City line with
winds more north-northwest behind it and west or west-southwest
ahead of it. Some mid level clouds behind front and a few spotty
showers. Will maintain mostly isolated shower or t-storm wording
into the early evening as front slips southeast. Instability
pretty weak but with enough heating and cool air aloft isold
thunder not out of the question. HRRR seems to be doing well in
showing a rather meager precipitation event.
&&
.SHORT TERM...(This afternoon through Saturday)
Issued at 632 AM CDT Fri Sep 9 2016
Just some minor pop adjustments based on current coverage. No
other changes.
.LONG TERM...(Saturday through Thursday)
Issued at 310 AM CDT Fri Sep 9 2016
Saturday looks quiet but cool with highs in the 60s to around 70.
Return flow, mixing and warm advection initiates Saturday night so
minimums not as cool.
Warm advection continues Sunday and with thermal ridge axis over
the fa and surface SW flow temperatures will warm to at or above
seasonal averages.
Strong cold front drops through roughly the NW half half of the
forecast area Sunday night. A majority of the model guidance dry
with fropa but will keep low pops going in case this changes.
Monday-Thursday...Cool air will filter into the region on Monday
with breezy northwesterly winds. While a few showers are possible on
Monday, no significant precip is expected. The primary question will
be the degree of cooling for Mon Night into Tue Night as surface
high pressure builds across the region. The GFS/ECMWF both bring the
the coolest air mass over the area on Mon Night. However, the degree
of cloud cover may impact temps on Monday Night. After a cool day in
the 50s to low 60s Tuesday, another chilly night is expected Tue
Night with the timing of return flow/warm advection behind the
surface high likely to impact overnight lows. Some lows at least
down into the upper 30s to low 40s would appear likely over much of
the area one or both of these nights, before temps begin to rebound
mid to late week. An upper trough expected to be over the western US
mid-week could impact precip chances over our area by late week, but
model guidance varies considerably with the evolution of this system.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 632 AM CDT Fri Sep 9 2016
VFR conditions through the period. Winds will be coming around to
the W-NW-N during the day as a cold front drops through the
region. Isold to sct shra will be possible along boundary with
some isold T this afternoon. Skies should be clearing in the wake
of the fropa.
&&
.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&
$$
UPDATE...Riddle
SHORT TERM...Voelker
LONG TERM...Makowski/Voelker
AVIATION...Voelker
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1048 AM CDT Fri Sep 9 2016
.DISCUSSION...
The KHGX radar is down for maintenance. Parts are on order and
should arrive later this morning. However, there is a possibility
that other parts may be needed. In the meantime, the Terminal
Doppler at Hobby Airport is available.
An upper low was evident at mid morning over the western Gulf
offshore of the central Texas coast. An upper air analysis and the
RAP analysis of the 700-300 mb mean height showed an Easterly Wave
from about the Sabine south to the Mexican coast. Isolated showers
were already developing this morning and expect more widespread
action once the convective temperature is reached -- which should
occur before noon. Once again isolated localized heavy rainfall
will be possible, especially in locations where colliding
boundaries occur. Made some tweaks to the wind forecast.
40
&&
.PREV DISCUSSION... /ISSUED 656 AM CDT Fri Sep 9 2016/
AVIATION...
Satellite showing developing (L)IFR stratus/lowering visibilities
forming along the I-35 corridor. This deck may develop further
eastward through 14Z, affecting CLL and UTS past sunrise. Scattering
out by 15Z with a weak upper low moving in from the Gulf creating
enough instability, with late morning temperatures warming into
the middle to upper 80s, to kick off widely scattered showers over
more southern counties. Depending on how much sun inland counties
receive this morning, thunderstorms may begin to cluster up during
the 19-22Z time frame, most likely impacting the greater Houston
area air fields into early evening. Scattering out through the
evening with returning showers, likely focused offshore and moving
inland during early Saturday morning. 31
PREV DISCUSSION... /ISSUED 419 AM CDT Fri Sep 9 2016/
DISCUSSION...
The western Gulf of Mexico mid/upper level low will make its way
to the Texas coast today and meander across the area over the weekend
and into the start of next week. Deepening tropical moisture levels
will spread across Southeast Texas as this system lingers near the
coast and will bring periods of showers and thunderstorms to the area.
A southward sagging cold front will become a focus for additional
storm development over the weekend. Locally heavy rainfall could
develop as boundaries interact with each other with location and
amounts partly dependent on how far the front makes it through the
area. For now, will continue to call for rainfall amounts through
the weekend averaging 1/2 to 1 inch with isolated amounts possibly
reaching 3 to 5 inches which could lead to some localized flooding.
Daily rain chances will remain in the forecast for much of next week.
42
MARINE...
The recently persistent onshore wind will continue through the day
before a weak inland front backs weakened winds to the east tomorrow.
Over the next several days, lower maritime pressures with weak
disturbances moving in from the east, will increase early week
shower and storm probabilities. This unsettled weather pattern
will keep higher rain/thunder chances around through the remainder
of the work week. Seas will generally range between 1 to 2 feet,
with a slightly higher swell of another foot arriving at mid-week.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 92 74 90 73 89 / 20 10 40 30 40
Houston (IAH) 90 74 91 74 90 / 40 10 40 30 50
Galveston (GLS) 89 81 89 79 87 / 40 20 40 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Discussion...40
Aviation/Marine...47
Area Forecast Discussion
National Weather Service Lincoln IL
1049 AM CDT FRI SEP 9 2016
.UPDATE...
Issued at 1045 AM CDT Fri Sep 9 2016
Upated the forecast twice this morning to remove the morning dense
fog wording and then to ajust the chances of showers and thunderstorms
today. A warm front has lifted north of CWA to I-80 by late
morning with southerly flow prevailing over central/southeast IL.
Scattered showers and isolated thunderstorms lifted northward
during the morning across central IL and were mostly along and
north of I-70. 1012 mb surface low pressure over central MO will
lift ENE into central IL late this afternoon keeping scattered
showers and a few thunderstorms around the rest of the day
especially north of I-70. RAP and HRRR models show highest chances
of convection shifting into easterly IL by early evening. Locally
heavy rain still possible into tonight with precipitable water
values of 1.4-2.2 inches. SPC day1 outlook continues with a
marginal risk of severe storms later this afternoon and evening
across CWA, while slight risk is over central/western MO and sw IA
into eastern KS. Humid today again with dewpoints in the upper 60s
to mid 70s. Highs near 80F from I-72 north and lower 80s in
southeast IL.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 321 AM CDT Fri Sep 9 2016
07z/2am surface analysis shows a 1006mb low over southwest Kansas,
with a stationary frontal boundary extending eastward into the
Ozarks. A large complex of thunderstorms has developed ahead of
this system across eastern Kansas into western Missouri, while
another smaller cluster of storms has formed further east near the
Saint Louis area. These storms will lift northeastward into the
KILX CWA early this morning, albeit in a weakening state as they
track further away from a 25-30kt 850mb jet streak oriented from
Texas N/NE into Missouri. HRRR seems to have a reasonable handle on
the situation, so have followed its solution closely for the
immediate short-term. Based on HRRR and latest radar trends, have
focused likely to categorical PoPs along/south of a Rushville to
Paris line this morning into the early afternoon...followed by
decreasing PoPs later in the day. Before the precipitation arrives,
widespread dense fog will be an issue across nearly the entire area
early this morning. Despite a high/thin overcast, very light winds
and temp/dewpoint spreads of 0-1F have led to fog development...with
07z obs showing visibilities less than 1 mile everywhere north of
the I-70 corridor. The fog will dissipate as showers push into the
area from the southwest: however, it appears several hours of
greatly reduced visbys will occur. As a result, have issued a Dense
Fog Advisory across all but the far SW and SE CWA through 14z/9am.
A vigorous short-wave trough evident on latest water vapor imagery
over Montana/Idaho will track eastward later today and tonight,
pushing a cold front toward Illinois. Numerous showers and
thunderstorms will develop within the increasingly moist airmass
ahead of the front. With precipitable water values once again
expected to exceed 2 inches, heavy rainfall and localized flash
flooding will be possible with the thunderstorms tonight. Since
rainfall amounts are expected to be less than previously forecast
with the initial surge of convection this morning, do not think
widespread flash flooding will be a major threat tonight.
Therefore...do not feel a Flash Flood Watch is warranted at this
time.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 321 AM CDT Fri Sep 9 2016
Cold front will swing through central Illinois on Saturday, with
showers and thunderstorms lingering across the east through the
morning. Once the front passes, brisk W/NW winds gusting to between
20 and 25 mph will usher a cooler and drier airmass into the region.
As skies clear and winds diminish, low temperatures will drop into
the upper 40s and lower 50s Saturday night. The cool/dry weather
will persist for both Sunday and Monday, with highs in the 70s and
lows in the 50s.
A brief warm-up is expected for Tuesday ahead of the next
approaching cold front when temperatures return to the lower 80s.
00z Sep 9 models are in good agreement with FROPA Tuesday night into
early Wednesday. Have therefore introduced low chance PoPs in the
Illinois River Valley on Tuesday, then everywhere Tuesday night.
After that, cooler/drier weather will return for Wednesday and
Thursday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 545 AM CDT Fri Sep 9 2016
A band of showers continues to push northeast into parts of west
central Illinois early this morning and expect this trend to
continue thru the morning. As this rain area moves across central
and east central Illinois, we see the visibilities improve
dramatically as the fog and cigs lift. Confidence on whether any
improvement in cigs and vsbys will last very long this morning is
rather low as the large area of rain tracks across the TAF sites.
Forecast soundings continue to suggest once the rain area moves
into central Illinois, we should see any cig/vsby improvement
deteriorate once again with low MVFR to IFR cigs into late morning
or early afternoon. Models try to bring the cigs up to low VFR
aftr 20z but additional showers and thunderstorms associated with
a cold front will bring the cigs back down to MVFR tonight.
Surface winds will be southeast to south at 8 to 13 kts today and
then veer more into the southwest at 5 to 10 kts tonight. Looks as
if FROPA will occur at PIA just after this forecast period.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
Area Forecast Discussion
National Weather Service Northern Indiana
904 AM EDT FRI SEP 9 2016
.SYNOPSIS...
Issued at 355 AM EDT Fri Sep 9 2016
Areas of fog...dense in many locations...will begin to slowly
dissipate after sunrise. Shower and thunderstorm chances will
return later this afternoon and increase tonight as low pressure
approaches the region. Locally heavy rainfall will be possible
along with an isolated strong thunderstorm. Temperatures will
continue to trend cooler through the weekend with less humid
conditions.
&&
.UPDATE...
Issued at 902 AM EDT Fri Sep 9 2016
Quick update to extend the advisory an hour to handle some
persistent areas of dense fog. A few locations are beginning to
show signs of slowly lifting/mixing out so only went for another
hour. Just outside the advisory visibilities have dropped as well,
but given the small window of concern opted not to expand further
south and will update SPS.
No other forecast changes at this time with focus shifting to
convective chances tonight.
&&
.SHORT TERM...(Today and Tonight)
Issued at 351 AM EDT Fri Sep 9 2016
Numerous issues to deal with in the short term period. Initial
problem is expansion of dense fog early this morning. Most reporting
sites from Knox Indiana to Hillsdale Michigan northward were
reporting zero to one quarter mile VIS at 07z. With weak high
pressure over the area and calm winds along with moist boundary
layer...widespread fog had developed in this region. Issued a dense
fog advisory for the morning. Upstream cirrus blow off from MO
convection as well as some stratus over IL may help offset further
expansion but a lot of uncertainty as usual with dense fog. Will be
monitoring conditions for any necessary changes to advisory.
Focus then shifts to chances for rain later this afternoon and
tonight. Models have come into a little better agreement with slower
arrival of pcpn...mainly after 00z. A few models do show initial
onset in the far southwest late this afternoon as residual activity
from early morning upstream MCS dissipates and drifts into the area.
Possible MCV from this convection may spark additional development
this afternoon. Will ramp up pops but a little slower than previous
forecasts. Main precipitation event expected tonight into Saturday
as nose of 30-40 kt low level jet moves into the area coincident
with mid level short wave and 2" PWAT axis within Theta-E ridge.
Latest RUC runs picking up on this with expansion of pcpn after 00z
from southwest to northeast. Locally heavy rain remains a concern
but main northern stream short wave now a bit slower and less
phasing with remnant tropical moisture surge as previous model runs
were hinting out. Warm rain processes still expected to dominate
with efficient rain rates. A great example of this occurred Thursday
morning with a few areas picking up 1 to 3 inches of rainfall in
about 3 to 4 hours. Severe risk remains marginal with deep layer
shear increasing to 30-40 knots but instability likely lacking given
overnight timing.
&&
.LONG TERM...(Saturday through Thursday)
Issued at 351 AM EDT Fri Sep 9 2016
Main northern stream trough to move through the region Saturday.
Will likely see rain ending during the morning from west to east
as cold front sweeps east. Secondary boundary still expected in
afternoon and could spark some additional showers with residual
moisture.
Large area of high pressure will drift across the area and provide
dry and comfortable weather from Sunday through Monday night. Next
northern stream short wave and associated surface front to cross the
region Tuesday and Tuesday night. This will bring the chance for
rain back into the forecast. This will be followed by another high
moving across the Great Lakes with reinforced cool and dry Canadian
air.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 700 AM EDT Fri Sep 9 2016
Areas of dense fog were over much of northern Indiana at 11Z.
Favored heavily conditional climatology with conditions improving
rapidly between 13Z and 14Z. Otherwise, moved back storm chances
for a later arrival time as a system approaches from the
southwest.
&&
.IWX Watches/Warnings/Advisories...
IN...Dense Fog Advisory until 10 AM EDT /9 AM CDT/ this morning for
INZ003>009-012>018.
MI...Dense Fog Advisory until 10 AM EDT this morning for MIZ077>081.
OH...Dense Fog Advisory until 10 AM EDT this morning for OHZ001-002-
004-005-015.
LM...NONE.
&&
$$
UPDATE...Fisher
SYNOPSIS...Lashley
SHORT TERM...Lashley
LONG TERM...Lashley
AVIATION...Skipper
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Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
546 AM CDT FRI SEP 9 2016
.SHORT TERM... (Through Late This Afternoon)
Issued at 345 AM CDT Fri Sep 9 2016
A band of thunderstorms containing heavy rainfall extended from MYJ
southeast through SUS to SAR. Some of these storms were producing
rainfall rates as high as 1-2 inches per hour. More complexes of
storms across portions of western MO and eastern KS will move
eastward through much of our forecast area for the rest of the
morning per the latest HRRR model runs. With the recent rainfall
amounts from Thursday will issue a Flash Flood Watch for parts of
central MO into southwest IL along the I-70 corridor and including
COU, JEF, and the St Louis metro area until early Saturday morning.
Most of the current shower/storm activity should shift east of our
forecast area by noon, although could not rule out isolated to
scattered storms redeveloping along outflow boundaries from morning
convection this afternoon. Should see enough partial clearing this
afternoon that high temperatures will be slightly warmer than
yesterday, and at or a tad above seasonal normals.
GKS
.LONG TERM... (Tonight through Thursday)
Issued at 345 AM CDT Fri Sep 9 2016
(Tonight)
Another round of TSRA expected to be either ongoing or develop
shortly into the evening hours as an approaching cold front, strong
mid level shortwave, and persistent rich moisture thru the column
interact to produce what should be a widespread rainfall for the
area. The most vulnerable areas that can be ascertained for now
will be locations that have already received heavy rainfall, namely
central MO into parts of east-central MO. Will issue a Flash Flood
Watch thru 12z/Sat to highlight heigtened flash flood threat given
expected high rainfall rates in any TSRA and should not take as much
as areas outside of FFA for flooding.
(Saturday - Monday)
Northwest flow aloft and high pressure at the surface should equate
to a quiet wx period here. Initially temps are expected to be below
average, but with southerly flow by late Sunday into Monday, temps
should rise back to above average levels by Monday.
GFS already develops rain chances by late Monday northwest of STL
metro, but prefer slower onset from EC.
(Tuesday - Thursday)
Rain chances should return by Tuesday with a cold front dropping
thru, with cooler air for Wednesday and Thursday with a 1028mb high
pressure settling over the Great Lakes.
TES
&&
.AVIATION... (For the 12z TAFs through 12z Saturday Morning)
Issued at 527 AM CDT Fri Sep 9 2016
Showers and storms will move through the taf sites this morning.
There should be a break in the rain this afternoon, then a line
of showers and storms along a cold front should move through the
taf sites late this evening and overnight. The cold front will
move through the taf sites late tonight. The surface wind will be
south-southeasterly today, then veer around to a west-northwest
direction late tonight after fropa.
SPECIFICS FOR KSTL: Showers and storms will move through STL this
morning. There should be a break in the rain this afternoon, then
a line of showers and storms along a cold front should move
through STL late this evening and overnight. The cold front will
move through STL late tonight. The surface wind will be south-
southeasterly today, then veer around to a west-northwest
direction late tonight/early Saturday morning after fropa.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flash Flood Watch through Saturday morning for Audrain MO-Boone
MO-Callaway MO-Cole MO-Franklin MO-Gasconade MO-Jefferson
MO-Lincoln MO-Moniteau MO-Montgomery MO-Osage MO-Saint
Charles MO-Saint Louis City MO-Saint Louis MO-Warren MO.
IL...Flash Flood Watch through Saturday morning for Madison IL-Monroe
IL-Randolph IL-Saint Clair IL.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Melbourne FL
919 AM EDT FRI SEP 9 2016
.DISCUSSION...
Current-tonight...Morning KXMR sounding shows continued warm mid-
levels with 700/500mb temps, +10.3C/-5.0C, respectively, and a
slowly deepening moisture profile (PWAT: 1.69"). Water vapor imagery
continues to show relatively dry mid/upper levels across much of the
Florida peninsula.
Cape wind profilers, again, show a deep, albeit weak, onshore wind
profile from near the surface through 10.0 Kft. Deep inverted
troughing continues to exist between the western Bahamas and Florida
Straits with associated convection. The surface reflection
associated with this troughing is forecast to still push slowly
westward through late day with its inherited cluster of showers and
storms. ENE/E winds will prevail across ECFL today with speeds
approaching 15 mph in the afternoon and some higher gusts likely.
High pressure ridging, east-west oriented, will continue to hang out
across north FL through the period.
WSR-88D MLB again shows very isolated coastal showers over the
waters this morning. The local HRRR model suggests afternoon
convection developing along the ECSB inland from the coast with
shower coverage becoming WDLY SCT to SCT and cannot rule out an
ISOLD lighting storm as well. This evening/overnight the interior
should become precipitation free while an ISOLD threat for showers
will exist over the coastal waters and along the coast from near the
Cape through Jupiter Inlet. Activity will generally move from east
to west at 5 to 10 mph.
High temps will reach the lower 90s across the interior and the
onshore flow near the coast will keep temperatures here in the upper
80s to around 90 degrees.
The lingering east-northeast swell will continue to produce a
moderate risk of strong/dangerous rip currents in the surf zone. The
times of greatest risk will be through late this morning and again
this evening.
&&
.AVIATION...Continued mainly VFR. Slow increase in deep layer
moisture, but mid level temperatures remain very warm and generally
not conducive for more than just isolated or widely scattered
convection. Greatest chance for late morning/early afternoon
isolated convection will be near the coast and this trend increasing
westward into the interior mid/late afternoon as the ECSB advances
inland. Evening/overnight shower chances from the deep, but light
onshore flow, should lie from the Cape through the Treasure Coast
once again. Expect brief MVFR conds invof convection.
&&
.MARINE...Current-tonight...Inverted troughing continues this
morning between the western Bahamas and the Florida Straits. East-
west oriented high pressure ridging remains situated across north
Florida. Generally an easterly wind component across the waters
today/tonight, albeit the range from ENE-ESE. Wind speeds mainly 6-
12 kts. Seas around 2 ft near shore and 2-3 ft offshore. Generally
just isolated showers for precipitation with westward movement, but
cannot rule out an isolated lightning strike either.
&&
.MLB Watches/Warnings/Advisories...
FL...None.
AM...None.
&&
$$
Sedlock/Volkmer
Area Forecast Discussion
National Weather Service Marquette MI
733 AM EDT FRI SEP 9 2016
.SHORT TERM...(Today and tonight)
Issued at 444 AM EDT FRI SEP 9 2016
00Z raobs/latest wv imagery and RAP analysis show a WSW flow aloft
btwn lo amplitude troffing over the Wrn Plains and an upr rdg over
the SE Conus. At the sfc, a weak hi pres rdg over WI/very dry airmass
depicted on the 00Z GRB raob /pwat 0.59 inch/ are bringing quiet wx
to the cwa. With lighter winds at the sheltered interior spots,
temps have fallen into the 40s at the cooler spots. But some mid clds
are aprchg fm the SW ahead of a shrtwv tracking ENEwd toward MN under
the WSW flow alf E of the Rockies trof. Some showers have also popped
up as far E as Ecentral MN/NW WI in the WAA pattern/deep lyr qvector
cnvgc ahead of this shrtwv. But dry llvl air depicted on the 00Z MPX
raob is restricting the coverage of these showers. More nmrs showers/
TS are present moving thru Scentral MN into Wi. Another stronger
shrtwv digging into the trof to the W is over the Nrn Rockies.
Main fcst concerns in the short term focus on timing/coverage of
pcpn associated with upstream shrtwvs moving thru the Plains trof.
Today...Although sct-bkn mid clds aprchg the SW border wl overspread
Upr MI this mrng, suspect the showers now moving into NW WI wl dspt
as they move into drier air and farther ahead of area of sharper
forcing ahead of shrtwv in SW MN per the latest HRRR fcst. But by
early-mid aftn, some of the sharper forcing/incrsg h85 theta-e advctn
ahead of this disturbance is fcst to influence the cwa. Although the
dryness of the llvls may tend to slow the spread of the showers and
limit their coverage, wl retain the flavor of the previous fcst and
show incrsg pops fm the SW. Although the incoming clds wl limit
insolation, fcst h85 temps arnd 14C wl still allow temps to rise well
into the 70s, especially away fm Lk MI moderation. With a
downsloping SW wind, temps near Lk Sup wl aprch 80.
Tngt...As stronger second shrtwv/accompanying dpva/deep lyr qvector
cnvgc/upr dvgc aprch fm the SW tngt, expect pcpn coverage and
intensity to increase. Overall, model qpf indicates the heavier rain
wl impact the Ecentral cwa under axis of some sharper mid lvl fgen/
deformation zn. Fcst wl thus show the hier categorical pops in this
area. As a sfc lo begins to intensify over Nrn Lk MI late, some
stronger N winds may dvlp over toward 12z over the W.
.LONG TERM...(Saturday through Thursday)
Issued at 458 AM EDT FRI SEP 9 2016
Models suggest that a progressive pattern will prevail through the
middle of next week. A mid/upper level trough moving through the
western Great Lakes Saturday will give way to ridging Sunday.
Another trough will move from the nrn plains to the nrn Great Lakes
from Monday into Tuesday will bring a cold front through the region
with much cooler air moving in Tuesday into Wednesday.
Saturday, Although the models have converged, the ECMWF remains
slightly stronger/slow compared to the GFS. A band of heavier pcpn
associated with stronger mid level fgen/deformation is likely to be
ongoing at 12z Sat into cntrl and/or east cntrl Upper Michigan.
MUCAPE values will support some embedded tsra that may linger over
the ern cwa in the morning. Breezy nw to n winds and 850 mb temps to
around 6C with the mid level trough and deep moisture over the area
will also support additional lake enhanced rain over the west near
IWD early and over n cntrl Upper Michigan into the afternoon.
Saturday night and Sunday, mid level and surface riding will quickly
build into the region Saturday night with clearing skies and
diminishing winds allowing temps to drop into the lower 40s inland
and the lower to mid 50s near the Great Lakes. Mostly sunny skies and
temps near normal around 70 should prevail Sunday as the high builds
toward the ern Great Lakes.
Monday-Wednesday, the GFS/GEFS and ECMWF were in better agreement
with the timing of the next mid level trough affecting the area late
Monday into Tuesday. A front will drop through the nrn lakes Monday
night that will provide a focus for shra/tsra chances. Models
suggest that 850 mb temps dropping into the 0C to 4C range behind the
front will bring more Fall-like conditions with highs in the lower
60s or possibly lower. Some light lake effect rain showers may also
be possible Tuesday even with the relatively dry airmass.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 732 AM EDT FRI SEP 9 2016
A SW flow btwn departing hi pres and ahead of an aprchg disturbance
wl grdly advect moister air into the Upr Great Lks, resulting in
some mid clds rolling into the TAF sites thru the day. But lingering
llvl dry air wl ensure VFR conditions even if some -shra impact the
sites this aftn. The aprch of a stronger disturbance tngt wl
generate more wdsprd showers tngt, resulting in deteriorating
conditions at SAW and IWD. Although a TS is psbl, the probability is
too lo to include in the TAFs attm. Right now, it looks like CMX wl
miss the heaviest rain, so conditions may not fall blo lo end VFR at
that site.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 444 AM EDT FRI SEP 9 2016
Plan on SSW winds up to 20 kts into tonight between departing
surface hi pres and an approaching cold front. The front will pass
Lake Superior late tonight into Sat as a rapidly deepening lo pres
moves from Wisconsin into SE Canada. N to NW winds up to 30 kts will
develop in the wake of this passing lo pres, and at least some
marginal gales are not out of the question especially over the E
half of the lake. As trailing hi pres follows into the Upper Lakes,
expect the winds to diminish steadily Sat night into Sun. But SW
winds will pick up to 25 to 30 kts on Sun night into Mon as the
hi shifts to the E and another cold front approaches from the NW.
Following the passage of this front later on Mon, there will be
another wind shift to the NNW up to 20 kts.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...KC
LONG TERM...JLB
AVIATION...KC
MARINE...KC
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1024 AM EDT FRI SEP 9 2016
.DISCUSSION...
The forecast looks on track so far this morning, so no changes are
planned at this time. The movement of showers in KY should continue
to take them on a path that passes north of our area, and this is
confirmed by the latest HRRR and RAP runs. 12Z soundings around the
area show a midlevel inversion that gets stronger as you go south,
so the potential for convective development in our area looks low.
Temperatures will be very warm again today, with highs on track to
hit the lower to mid 90s.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
DGS
Area Forecast Discussion
National Weather Service Omaha/Valley NE
639 AM CDT FRI SEP 9 2016
.SHORT TERM...(today through Sunday)
Issued at 320 AM CDT FRI SEP 9 2016
The primary forecast concerns are in regards to thunderstorm
coverage and intensity from today into the early evening hours.
The 500 mb pattern will undergo some changes in this period. A
shortwave trough initially extending from eastern MT into UT will
move eastward into the northern and central plains today and then be
east of our area by late tonight. Another trough will dig into the
Pacific Northwest and southwest Canada on Sunday.
850 mb analysis from last evening showed decent moisture from the
southern Plains northward into KS and NE. Dewpoints of 14-16 degrees
C were as far north as KOAX and KLBF. 700 mb moisture was highest
from the TX panhandle into KS...and an MCS over KS may have been at
least partially inhibiting the northward transport of mid level
moisture. The KOAX sounding had a PW value of 1.38 inches...but it
was quite a bit higher to the south. Values of 1.73 inches were in
place and KTOP and 1.72 at KDDC. Best 12 hour height falls (around
40 meters) were over eastern MT last evening. At 300 mb...two
primary jet segments were noted. One around 110 knots from WI into
upper MI and another around 100 knots from along the British
Columbia coast into northwest WA. Water vapor satellite imagery
early this morning showed a couple of disturbances upstream from our
area that will move eastward today. 08z surface analysis had
southerly flow across eastern NE and southwest IA with dewpoints in
the lower 70s F south and in the 60s north. A cold front stretched
from eastern North Dakota into western NE. That front will move
eastward today and become better defined. Some spotty showers did
occur overnight...mainly from west of Lincoln toward Fremont...
Tekamah...Onawa and Denison.
Today...the general consensus from the short range model guidance is
that showers and thunderstorms should increase in coverage today...
with activity mainly along a wind shift/cold front. Chances will end
early to mid evening...lasting the longest near the MO border. 0-500
meter ML CAPE values should reach 1500-2500 J/kg along and ahead
of the front this afternoon...with 30-40 knots of 0-6 kilometer bulk
shear. Some supercell storms will be possible...with large hail and
damaging winds the most likely hazards.
Most recent (06Z) RAP13 model is a bit faster than the operational
HRRR (and the RAP13 seems too fast). The ESRL experimental HRRR is
even slower that the operational HRRR. Leaned mostly toward the
operational HRRR for timing.
Highs today should reach the mid to upper 70s north and lower to mid
80s south. North/northwest winds will bring in cooler and drier
air for tonight and then dry weather should continue into Sunday.
Highs Saturday will be in the 70s...then brisk southerly winds
Sunday should push highs back into the upper 70s and lower 80s.
.LONG TERM...(Sunday night through Thursday)
Issued at 320 AM CDT FRI SEP 9 2016
500 mb flow will become split early next week with one branch to the
north across Canada while a trough digs in the far western CONUS and
develops a closed low over CA by Monday night. The 00Z GFS and ECMWF
agree that a cold front will move into the area from the northwest
on Monday. Initially during the day...precipitation chances look
fairly low. Probabilities will go up Tuesday night especially for
locations along and north of the front. Model solutions for the
large scale pattern diverge by Wednesday night...with the ECMWF more
progressive with opening up the closed low over the Rockies and the
GFS holding much farther west.
&&
.AVIATION...(12Z TAFS for KOFK...KLNK and KOMA.)
Issued at 633 AM CDT FRI SEP 9 2016
Variable conditions are expected through the first 6-9 hours of
the TAF cycle as low clouds and patchy fog move across the sites.
A cold front will drop south through the area today bringing a
chance for showers and thunderstorms this afternoon. After the
front passes, skies should begin to clear overnight with northwest
winds increasing on Saturday.
&&
.OAX Watches/Warnings/Advisories...
NE...None.
IA...None.
&&
$$
SHORT TERM...Miller
LONG TERM...Miller
AVIATION...Kern
Area Forecast Discussion
National Weather Service Mount Holly NJ
1021 AM EDT FRI SEP 9 2016
.SYNOPSIS...
A very weak cold front from Concord New Hampshire to Columbus Ohio
will slide down into northeast Pennsylvania and northern New Jersey
this evening, then lift north into New York State Saturday. A stronger
cold front will move east through the mid Atlantic states late
Saturday night. High pressure then will build eastward into the region
early next week. Another cold front will cross the mid Atlantic states
late Wednesday, followed by Great Lakes high pressure for the end
of the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
1020 AM: ESTF update. Raised thunderstorm probs east central and
northeast Pa and also NNJ for expected afternoon convection. Also
raised temps and dews far southern NJ. The 1155 AM update to
extend the advisory is looking to be likely. additionally may
expand the heat advisory into Monmouth and Somerset counties and
southward through southern NJ.
Forecasting record or record equaling at ACY PHL ILG TTN GED.
A very weak cool front-or trough, seen at 13z from Concord NH
to Franklin PA will ever so slowly ease southward and be the focus
of afternoon convection. 1000J ML Cape but weak under 25 kt 0-6KM
shear should result in a few gully washers in 2 to 2.25 pwat axis
(northern portion of that axis)...probably I78-I80 (RDG/ABE/TTN)
region mid-late afternoon that may slide down to PHL-ACY in the 6
to 10 pm time frame. -5C at 500MB is a potential capping problem,
especially if we cant pool more moisture (buoyancy) along that
boundary near I80 this afternoon.
Monitoring the HRRR for convection. Not yet believing its
boundary evolution for Monmouth and Ocean counties early this
afternoon.
Max in phl today 95 is solid, plus or minus 2 degrees...yes there
is a chance of 96 or 97 at PHL.
Tonight...Convection (dying tstms to showers in the weakly capped
environment (-5C at 500 MB)), whatever there is...may linger into
the night near the southward sliding wind shift to just south of
KRDG-KTTN.
It should be a few degrees cooler tonight than it was this morning
when min temps were 15 to 21 degrees above normal (PHL 80, ABE
77). Still though...about 15 above normal where rain cooled air
doesn`t bring it down a little more than the guidance fcst.
Otherwise the afternoon 330 PM fcst basis will be a 50 50 blend of
the 12z/9 GFS/NAM MOS.
&&
.SHORT TERM /SATURDAY/...
Hot (near record) and humid with remains of the wind shift vcnty
KRDG-KTTN drifting northward and having little or no impact on
our afternoon weather. Mentioned near record heat instead of
record, since the records are slightly higher.
The 330 PM forecast will be a 50 50 blend of the 12z/9 gfs/nam mos
unless otherwise noted. The temp bias will probably result in our
forecasting temps 3F warmer than guidance, especially since the
day starts with 20C, warmest 850 temp for our area in this
particular heat episode.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Saturday night through Sunday:
A very strong mid-level ridge will still be established across
the Southeastern United States.
Saturday night...Muggy overnight lows possibly not falling below
the upper 60`s and low 70`s are quite possibile as well for a good
portion of the region with some increase in the clouds and
continued southerly flow ahead of the cold front. The front
weakens it as it approaches the region with the Great Lakes
trough lifting northeast toward Quebec, sending the best mid level
dynamics for showers and thunderstorms well to the northwest of
the region. Across our region only a few spotty showers and
thunderstorms are likely to occur just ahead of the frontal
passage.
Sunday through Tuesday:
Behind the cold front, a more seasonable airmass with closer to
normal temperatures and mostly sunny skies are expected for the
early part of next week. This is thanks to a high pressure system
passing over our region. Did not did deviate much from the mean of
various ensemble guidance in this period given the low spread in the
data.
Wednesday and Thursday:
On the backside of the high pressure system, southerly flow will
allow for an increase in the heat and humidity by Wednesday.
Another cold front will then try and attack the ridge over the
southeast but like it`s predecessors it should decay with the best
mid level dynamics passing northwest of the region. This would
only bring us a few spotty showers and thunderstorms. Some
differences in model timing are present with the ECMWF being
consistently slower than the GFS the last few model cycles. With
some spread on the frontal timing in various ensembles as well
will stay close to the ensemble consensus in this period.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Today...VFR sct-bkn aoa 5000 ft. there may be a brief IFR tstm
vcnty KRDG,KABE,KTTN in the 21z-01z/10 time frame? west to
southwest wind gust 15 kt.
Tonight...VFR sct-bkn aoa 5000 ft. Any lingering thunderstorms to
the north of KPHL during the evening should die as a shower or
sprinkle near KPHL around 06z. winds light southwest...possibly
trending light north or northeast late at KABE/KRDG/KTTN.
Saturday...Mainly VFR. Winds becoming southwest gusty 15 to 20 kt
during the afternoon. An isolated shower or storm can`t be ruled
out with a very brief restriction.
OUTLOOK...
Saturday night and Sunday: Mainly VFR, Southwesterly winds shifting
to west or northwesterly around 10-15 knots with higher gusts.
Isolated showers and thunderstorms may lower ceilings and
visibilities for brief intervals Saturday night.
Sunday night through Tuesday: VFR, with winds 10 knots or less.
&&
.MARINE...
Winds and seas should remain below SCA criteria through Saturday.
West to southwest this morning become southerly this afternoon
through Saturday.
OUTLOOK...
Seas will remain below six feet on the ocean throughout the
outlook period. However seas may end up in the five to six foot
range Saturday night and Sunday. Wind gusts may reach 25 knots on
the ocean waters at times Saturday afternoon into Sunday from the
southwest but shifting to the northwest on Sunday. An isolated
shower or thunderstorm is possibile Saturday into Saturday night
as well. Lower seas and winds for Monday and Tuesday.
RIP CURRENTS...a low risk for the formation of dangerous rip
currents is expected today. The probable risk for the formation of
dangerous rip currents tomorrow is moderate.
&&
.CLIMATE...
Heat (4-6 day heat wave) in progress as we go through this week.
Heat wave count as of today: ILG 3 days; PHL ABE RDG 2 days so far.
RER equaled at ABE on 9/7. New RERGED and RERTTN equal ydy.
Records being forecast at ACY PHL ILG TTN and GED today.
Here are the record high temperatures for Today and Saturday, the
hottest days in this stretch.
Friday- 9/9 Saturday 9/10
ACY 92-1915 95-1983
PHL 94-1884 97-1983
ILG 94-1939, 1915 98-1983
ABE 95-2015 96,1983
TTN 93-1959 101,1983
GED 92-2015,1985 93,1985
RDG 94-2015, 1959 100,1983
MPO 88-1964 89,1983
So far Philadelphia International Airport has recorded 43 days
where the high temperature has gone over 90 degrees this is sixth
all time. Several other years had more days over 90 degrees they
include 2010 with 55 90 degree days and 1991 with 53 90 degree
days. Additional years include 1995 and 1988 with 49 days over 90
degrees and 46 days back in 2002. A few more 90 degree days are
still likely to occur this week, another 90 degree day possible
next Wednesday.
The table below for reference
RER # 90 deg days: Season total, Season RER, Sept rer, Sept mean then
closing out with Season rank and POR. You can see in the period of
record (POR) that the number of 90 degree days this year will be
top 5 in the detailed historical record, further supporting one
of the warmest summers in the period of record.
The 90 degree data below is through yesterday - September 8.
2016 RER 9/RER 9/Mean Season rank POR
ABE 35 41-1966 7-2015 1 #4 prob rise to #2-3 1922
ACY 30 46-2010 9-1961 1 #6 now could tie #4 1874
PHL 43 55-2010 8-1970 2 #5 1872
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 6 PM EDT this evening for PAZ060>062-070-
071-101>106.
NJ...Heat Advisory until 6 PM EDT this evening for NJZ015-017>019.
DE...Heat Advisory until 6 PM EDT this evening for DEZ001>003.
MD...Heat Advisory until 6 PM EDT this evening for MDZ008-012-015-
019-020.
MARINE...None.
&&
$$
Synopsis...Gaines
Near Term...Drag/Johnson 1021
Short Term...Drag/Johnson
Long Term...Gaines/O`Hara
Aviation...Drag/Gaines/Johnson
Marine...Drag/Gaines/Johnson
Climate...
Area Forecast Discussion
National Weather Service La Crosse WI
353 PM CDT FRI SEP 9 2016
.SHORT TERM...(This evening through Saturday)
Issued at 352 PM CDT Fri Sep 9 2016
At 3 PM, a short wave trough was moving northeast across
Wisconsin. This system produced a widespread area of 1 to
4 inches of rain across the forecast area. With the radar
underestimating the rainfall south of Interstate 90 corridor by up
to 25 percent, would not be too surprised that there may be some
areas which saw around 5 inches in northeast Iowa and southwest
Wisconsin. With this initial wave pushing the surface front as far
south as the Interstate 80 corridor, the best instability (up to
1500 J/kg) has ended up in southern Iowa and central Illinois.
Further to the west, a much strong short wave trough was located
across southwest Minnesota and western Iowa. This system will move
east through the area tonight. The RAP continues to show that the
elevated instability will climb up to 750 J/kg across northeast
Iowa and southwest Wisconsin this evening. In addition, there will
be moderate 925 and 850 mb moisture transport, warm cloud layer
cloud depths to around 4 km, and precipitable water values
approaching 2 inches. This will result in highly efficient rain
producers. Taking all of this in account, anticipating that some
areas may see up to another inch from this system this evening.
With ongoing flooding occurring in some areas and saturated soils
across the region...kept the Flash Flood Watch going through
10.06z. However would not be too surprised that we are able to
cancel this watch early.
On Saturday morning, a short wave trough currently over South
Dakota will move across northern Wisconsin. This system will
produce some scattered showers mainly along and north of
Interstate 94.
.LONG TERM...(Saturday night through Friday)
Issued at 352 PM CDT Fri Sep 9 2016
The next chance of rain will likely occur from Monday night into
Tuesday. As the 925 and 850 mb moisture transport increases ahead
of the cold front and approaching short wave trough, precipitable
water values will climb into the 1 to 1.5 inch range. However
considering the progressive nature of this system and warm cloud
layer depths less than 3.5 km, not anticipating any additional
flooding from this system. While the 0-1 km mixed layer CAPE will
be climbing up to 1250 J/kg ahead of the front, both the 0-3 and
0-6 km shear will be lagging the front; thus, not anticipating any
threat of hail, wind damage, or tornadoes from this system.
In the wake of this front, high pressure will build across the
region. This will help provide us with some much needed drying
through Thursday. As a result, the weather still looks good for
our Open House which is on Thursday from 2 PM to 7 PM. Hope to see
some of you there.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1235 PM CDT Fri Sep 9 2016
Area of showers with embedded scattered thunderstorms across the
region as of 09.17Z will continue to move eastward through the
early afternoon hours, pushing east of KRST by 09.18Z and east of
KLSE by 09.20Z. After a brief break, expect additional showers and
storms late this afternoon/early evening as a cold front moves
through the region. Brief MVFR/IFR conditions are possible with
stronger storms/heavier rain; otherwise mainly VFR conditions are
expected into the early evening. Will continue with idea of MVFR
ceilings overnight behind the front for now, but ceilings may be a
bit higher and need amending. Expect a return to total VFR
conditions by late in the period with skies slowly clearing. Light
south-southeast wind this afternoon will abruptly shift to the
northwest behind the front.
&&
.ARX Watches/Warnings/Advisories...
WI...Flash Flood Watch until 1 AM CDT Saturday for WIZ053>055-061.
MN...Flash Flood Watch until 1 AM CDT Saturday for MNZ095-096.
IA...Flash Flood Watch until 1 AM CDT Saturday for IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...ROGERS
Area Forecast Discussion
National Weather Service Grand Rapids MI
330 PM EDT FRI SEP 9 2016
LATEST UPDATE...
Synopsis/Short Term/Long Term/Hydro/Marine
.SYNOPSIS...
Issued at 330 PM EDT Fri Sep 9 2016
A low pressure system will bring showers and thunderstorms late
tonight through midday Saturday. A cooler and drier airmass will
move in behind this system for Saturday night through Monday as
fair weather returns as high pressure builds in. Another low
pressure system will bring a chance of showers and thunderstorms
Tuesday with cooler temperatures to follow for mid to late next
week.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 330 PM EDT Fri Sep 9 2016
Our primary short term fcst concerns involve determining
convective potential for late tonight through around 18Z Saturday.
Fair wx will continue through late this afternoon. Rgnl radar
trends show showers over northern IL/IN and scattered showers should
begin to develop over our southern fcst area this evening as
elevated instability begins to increase a bit to the north of the
quasi stationary frontal boundary near the MI/IN border.
Scattered convection will develop very late tonight with the
approach of the strengthening sfc low and cold front. The severe
wx threat very late tonight through 18Z Saturday is low given
unfavorable frontal timing and relatively weak instability.
However we still cannot rule out potential for isolated strong to
severe storms Saturday morning through around 18Z Saturday given
strong shear and upper level dynamics/pva in conjunction with
forcing from the front and ample low level moisture. It does seem
though that given the timing of the system that the much better
chance for severe wx tomorrow will be east to southeast of our area
across SE lwr MI and OH.
Breezy conditions will develop Saturday afternoon and the strong
west winds will quickly advect a cooler and drier airmass into our
area. Fair weather will return late tomorrow through Sunday night
as high pressure builds in.
.LONG TERM...(Monday through Friday)
Issued at 330 PM EDT Fri Sep 9 2016
The big story to me is the colder temperature behind the cold front
Wednesday into Friday. It would not be out of the question there
could be some patchy frost in our NE counties Thursday morning.
Beyond that there is convection wednesday that is associated with
the cold front. This does not seem like a big deal actually. Many
areas may not even see rain from this front.
We continue to see a progressive upper air pattern this week. The
next system is currently a closed upper low in the Gulf of Alaska.
It tracks eastward and opens up as it crosses the Canadian Rockies
but thanks to a building subtropical high this system does not get
as far south (jet core). So that means the best dynamics go north
of our area. This suggest to me the threat for convection is more
limited with this next system. In fact the most unstable cape is
mostly under 500 j/kg. Many areas may not even see rain from this
system. Even so with Lake Michigan as warm as it is, water spouts
may be possible.
One other aspect of this is with the jet core north we should not
have a lot of low clouds once we get into the cold air, which means
we could see temperatures fall into the 30s in our NE CWA. That
could mean some patchy frost.
With upper ridging developing this cool weather will not not last
all that long, there will be a warming trend into the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday)
Issued at 155 PM EDT Fri Sep 9 2016
I do believe the I-94 TAFs should go VFR within the next 2 hours.
Then VFR should prevail into the early morning hours of Saturday.
At that point a low developing on the front will track northeast as
per the NAM12 and RAP models. That will bring a concentrated area of
showers and thunderstorms into the TAF sites in the 06z to 15z time
frame. This will bring IFR conditions with it ceilings and
visibilities fall in moderate to heavy rain and some fog.
Thunderstorms are possible. Once that system gets through the rain
should end but there is a fair chance of a line of storms forming on
the cold front during the afternoon. Not being so sure of this I
went with VCTS after 16z to cover that. The low clouds will not not
clear until the cold front comes through later in the day.
&&
.MARINE...
Issued at 330 PM EDT Fri Sep 9 2016
Will hoist a small craft advisory from St. Joseph to Manistee from
14Z Saturday through Saturday night as west winds will ramp up
significantly to 15 to 25 kts with gusts to around 30 kts Saturday
afternoon. This will cause wave heights to build to 4 to 7 feet. A
beach hazards statement is also in effect from St. Joseph to
Manistee Saturday through Saturday night.
&&
.HYDROLOGY...
Issued at 330 PM EDT Fri Sep 9 2016
Rivers are falling after the recent heavy rainfall. Showers and
storms are expected late Friday night into Saturday afternoon. Less
than a half inch of precipitation is expected across the area with
locally heavy rain possible. River rises are possible, and some
smaller rivers and streams may rise to near bankfull by Saturday
night.
&&
.GRR Watches/Warnings/Advisories...
MI...Beach Hazards Statement from Saturday morning through
Saturday night for MIZ037-043-050-056-064-071.
LM...Small Craft Advisory from 10 AM Saturday to 8 AM EDT Sunday for
LMZ844>849.
&&
$$
SYNOPSIS...Laurens
SHORT TERM...Laurens
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...63
MARINE...Laurens
Area Forecast Discussion
National Weather Service Lincoln IL
256 PM CDT FRI SEP 9 2016
.SHORT TERM...(This evening through Saturday)
ISSUED AT 253 PM CDT Fri Sep 9 2016
Latest radar mosaic shows developing areas of showers with pockets
of moderate to heavy rain over the IL river valley nw of I-55. SPC
day1 update continues a slight risk of severe storms late this
afternoon and evening south of I-72, with 5% risk of damaging winds
and tornadic supercells. Airmass is getting more unstable over
southeast CWA with CAPES up to 1500-2500 J/KG at mid afternoon south
of I-70. A few stronger thunderstorms developing around St Louis
ahead of MCV over central MO and tracking northeast. Expect this
convection to continue to expand as it tracks northeast into central
and southeast IL late this afternoon and evening with areas south of
I-72 having the slight risk of severe and heaviest rainfall where
precipitable water values are 1.5-2.2 inches. Highest chances of
convection to shift into eastern IL by early evening, and then
expect a lull in convection for a time after dark until cold front
in central IA increases chances of showers/thunderstorms again
overnight as it moves into central IL late tonight. The cold front
to sweep through southeast/eastcentral IL Saturday morning where
chances of showers and a few thunderstorms lingers, then drier,
cooler and breezy conditions expected behind the front by Saturday
afternoon.
Held off with a flash flood watch as most of our CWA did not
receive much rainfall so far today, plus heaviest rainfall will
occur over southern half of CWA which did not see as much rainfall
Wednesday night and Thurday. High resolution models have trended
lower with qpf tonight and shifted heavier qpf into areas from I-72
south where 0.75-1 inch with locally heavier amounts. Between a
quarter and half inch of rain expected over northern CWA through
tonight.
Lows overnight to range from the low to mid 60s over the IL river
valley, to the muggy lower 70s in southeast IL. Highs Saturday to
mostly be in the mid 70s, with upper 70s over southeast IL with
areas near the Wabash river near 80F.
&&
.LONG TERM...(Saturday night through Friday)
ISSUED AT 253 PM CDT Fri Sep 9 2016
Generally quiet weather and cooler than normal conditions are
expected across central and southeast Illinois through the longer
range of the forecast. Surface high pressure and neutral upper flow
will dominate into Monday night. Then, a northern stream wave, with
the main energy tracking east across Canada, will push a cold front
into the area for Tuesday into Wednesday. This frontal passage will
be the main threat for organized rainfall over the next several
days. However, given the position of the main wave and the lack of
significant moisture return ahead of the front, it is not likely to
be a major rain maker. The warmest temperatures of the week should
be Tuesday ahead of the front, with the remainder of the period
seeing daytime highs of 80 degrees or below.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1258 PM CDT Fri Sep 9 2016
An MCV over central MO will lift ENE into central IL late this
afternoon and exit into IN early this evening. Expect more
numerous showers and isolated thunderstorms to develop with this
feature during the afternoon as it tracks into central IL and then
diminish from the WSW between 23Z-02Z. MVFR ceilings and vsbys
will occur at times with this convection with lowest ceilings at
BMI which currently is near 1k ft. HRRR and RAP models show a lull
in convection after sunset this evening before a cold front over
central IA pushes southeast across central IL later tonight and
early Sat morning. More convection possible along and ahead of
this front overnight into early saturday along with IFR to MVFR
ceilings and vsbys. Then breezy WSW winds take shape behind the
cold front during Saturday morning with gusts of 15-20 kts.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Bak
AVIATION...07
Area Forecast Discussion
National Weather Service Northern Indiana
354 PM EDT FRI SEP 9 2016
.SYNOPSIS...
Issued at 349 PM EDT Fri Sep 9 2016
Showers and thunderstorms are expected tonight ahead of a warm
front. Locally heavy rain is possible along with the potential for
strong to severe storms. Lows will be in the middle 60s. A cold
front will sweep across the area on Saturday with additional
chances for showers and thunderstorms...mainly along and east of
Interstate 69.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 349 PM EDT Fri Sep 9 2016
Focus of forecast on this evening with increasing concerns for at
least 1 round of widespread rain, with embedded storms both in and
on back edge of the rain. Radar currently showing returns over the
SW parts of the area struggling to reach the ground as any
moisture goes to saturation of a large EML as reflected on 12z ILX
sounding. Attention will shift more to the southwest where 2
features of interest reside. The first is the effective surface
warm front located from northeast of St Louis to across the Ohio
River. The second is the remnants of Hurricane Newton work into
the region tonight with surface low pressure developing somewhere
between Chicago and Ft Wayne. These 2 features will help bring the
following elements in 1) Tropical moisture with PWATS in excess of
2 inches resulting in efficient rain producers 2) Increase in low
level jet to 40 kts or more resulting in pockets of increased bulk
shear 3) 0- 1 km Helicity increasing to potentially 100 to 200
m2/s2. HRRR has been fairly consistent in area of rain/embedded
storms taking shape SW of the area and moving in near/just after
00z. SWOMCD just issued highlighting this threat with potential
for watch out to our SW shortly. Have adjusted pop trends faster
with cat pops across the area by late evening. Mention of heavy
rain added to grids tonight but no hydro headlines as convection
should be progressive. This doesn`t eliminate any threat for brief
training/redevelopment from boundary interactions.
Everything may exit the area after 6z with potential for a lull
until the cold front approaches from the NW Saturday. At the present
time it appears that locations around and east of I-69 stand the
best chance for shower/storm redevelopment with trends increasing as
they leave the forecast area. Only minor changes for the time being
given greater focus on this evening.
&&
.LONG TERM...(Saturday Night through Friday)
Issued at 349 PM EDT Fri Sep 9 2016
Few changes to long term given potential short term weather
concerns and overall lack of sensible weather issues outside
Tuesday/Tuesday night. Longwave trough will dig into the western
states with a piece of it breaking off and heading east across the
northern Lakes to bring a chance of showers/storms. Otherwise high
pressure should dominate conditions before and after this feature
with seasonable temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 142 PM EDT Fri Sep 9 2016
Fog/stratus mixed out into sct cu deck which should persist this
aftn. Shra over ern IL expected to lift ne across nrn IN this eve
and expand/intensify as llj strengthens south of warm front
resulting in sct ts during this time. Flight conditions expected
to grdly lower to mvfr/ifr overnight as warm front moves through.
Shra should decrease in coverage in warm sector Sat morning with
increasing coverage of shra/ts early aftn as cdfnt approaches.
&&
.IWX Watches/Warnings/Advisories...
IN...Beach Hazards Statement from Saturday morning through Sunday
morning for INZ003.
MI...Beach Hazards Statement from Saturday morning through Sunday
morning for MIZ077.
OH...NONE.
LM...Small Craft Advisory from 10 AM Saturday to 8 AM EDT Sunday for
LMZ043-046.
&&
$$
SYNOPSIS...Fisher
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...JT
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AREA FORECAST DISCUSSION
National Weather Service Jackson KY
704 PM EDT Fri Sep 9 2016
.UPDATE...
Issued at 704 PM EDT FRI SEP 9 2016
Recent radar imagery shows that the afternoon showers have exited
the forecast area. There are a few additional showers popping up
in north-central KY so cannot rule out a rogue shower or two in
the far north over the next few hours. Beyond that, the area
should stay dry overnight. Also backed off on sky cover as most of
the afternoon cu has dissipated.
Did a quick refresh to the hourly temps to reflect most recent obs
and sent updates to NDFD and web servers.
UPDATE Issued at 433 PM EDT FRI SEP 9 2016
Reloaded the full set of grids with the Shortblend and Superblend
after taking operations back from RLX. From these blends, updated
pops and temperatures in the near term per recent radar imagery
and obs, respectively.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 300 PM EDT FRI SEP 9 2016
18z sfc analysis shows an old boundary north of the Ohio River
with low pressure and cold front approaching from the northwest.
High pressure has held on across the south today keeping the
weather quiet, rather sunny, warm, and humid there. To the north,
though, a lingering cluster of light showers has held together as
it moved slowly east into the CWA but also did not develop much
further despite the relatively unstable and high PW airmass. In
fact, the thicker clouds from this area of showers likely kept
anything of note from developing by suppressing the sfc based
instability. Due to the dichotomy of the clouds today,
temperatures varied from upper 70s to low 80s north to the upper
80s and low 90s south. Mid 80s were mostly found through the
middle part of the CWA. Do still expect temps to rebound in the
north over the next couple of hours. Dewpoints, meanwhile, also
varied geographically from around 70 degrees north to the low to
mid 60s south. Southwest winds of around 10 mph and, at times,
gusting to between 10 and 20 mph kept the sticky air moving for
most places.
The models are in good agreement aloft through the short term
portion of the forecast as they all depict a decent shortwave
trough crossing the Ohio Valley late Saturday into early Sunday
morning. The extent of the energy associated with this feature
will brush through northern Kentucky and likely help to generate
storms for our area later Saturday. Heights will then flatten out
in its wake leading into Sunday morning. Given the good model
agreement will favor a blended solution with a lean toward the
HRRR for near term specifics and the NAM12 beyond that.
Sensible weather will feature a fairly quiet and warm/muggy
evening with just a few showers or thunderstorms around, should
things be able to develop in the next few hours. These will die
out quickly following sunset with a quiet night on tap in the warm
sector awaiting the approaching cold front. Any fog overnight
should be confined to the deeper valleys, unless we see more
shower activity than anticipated late this afternoon and evening.
For Saturday, another warm day will lead into an afternoon of
better instability and potential for strong to severe storms. The
cold front bringing in good sfc convergence will arrive sometime
after 21z and be accompanied by good upper level support in
addition to rather high PW air. There will be a threat for
damaging winds with the strongest of the storms, in addition to
heavy rains, into the evening. The front and convection clears
off later that night with cooler and drier air pushing in behind.
Made only minor adjustments to the temperature grids for terrain
distinctions tonight and Saturday night...though with opposite
effects - typical ridge/valley tonight and a more CAA pattern
tomorrow night. As for PoPs, ended up close to MOS with the fropa
on Saturday and minimized them outside of that time.
.LONG TERM...(Sunday through Friday)
Issued at 331 PM EDT FRI SEP 9 2016
Overall, a quiet period typical of this time of year is in store,
with models in agreement. A cold front will be exiting southeast
of the region early Sunday. High pressure behind the front will
pass by to our north under fairly zonal flow, and bring fair
weather through midweek. The air mass will be seasonably dry,
allowing for some cooler night time temps, especially in valleys.
An upper trough dropping southeast over New England will allow a
cold front to trail southeast through our area on Wednesday and
Wednesday evening. Moisture will be limited, and getting pinched
off as the front sinks southeast. Only 20% POPs have been used in
the northern part of the area. Behind this, another surface high
will pass by to our north and northeast. The heart of the cooler
and drier air associated with the high will miss us, but we may
at least be glanced by the air mass. As the high passes to our
east, moisture will start to make more of a comeback on return
flow from the south on Friday. Can not rule out some
showers/storms with this, but ridging aloft and a lack of features
will probably keep it very limited.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 230 PM EDT FRI SEP 9 2016
Aside from some lingering MVFR cigs around over the next few
hours, associated with widely scattered, and mostly dissipating
showers, conditions will be VFR through the forecast period out
ahead of an approaching cold front. Although some fog can be
anticipated in the valleys Saturday morning, this will likely not
impact any TAF sites. Winds will be breezy out of the southwest
through the rest of the afternoon with gusts to 15 or 20 kts
possible, mainly north. Later they will settle down to light and
variable before picking up again on Saturday from the southwest at
5 to 10 kts with higher gusts possible in the afternoon.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...HAL
AVIATION...GREIF
Area Forecast Discussion
National Weather Service Miami FL
514 PM EDT FRI SEP 9 2016
.DISCUSSION...
For the short term, the major synoptic feature is a weak area of
low pressure across the Florida Straits. The local LAPS analysis
indicated a weak closed low at 19z and for the last 3 to 4 hours
has indicated an increasing trend in the surface vorticity. This
is consistent with recent visible satellite imagery indicating a
low level swirl with active convection to the southeast.
The forecast for tonight...The general consensus of the global
models and the latest HRRR model as well indicate a general west
to southwest movement of the weak surface low across the Florida
Straits tonight, with recent model guidance consensus indicating
it could be to the southwest of the Florida Keys on Saturday
morning. Regarding any potential for possible tropical formation,
please monitor and consult the products of the National Hurricane
Center. As for any impacts on South Florida as it tracks west to
southwest tonight, expecting bands of showers and isolated
thunderstorms to continue radiating outward from the low and
mainly impacting the southern portion of the peninsula and the
adjacent Gulf and Atlantic waters. With the passage of bands of
showers, brief heavy downpours and gusty winds can be expected.
For any marine impacts, consult the marine discussion below.
Forecast for Saturday and Sunday...
If the aforementioned low continues to track westward as indicated
above, this will result in deep moisture across the region in its
wake with chances of showers and thunderstorms over the weekend.
An upper level low currently east of the Carolinas will likely continue
to retrograde southwest over the weekend and will enhance chances
of showers and thunderstorms, with activity possible across the
Gulf and Atlantic waters as well.
Forecast for early next week...
A weak trough currently east of Puerto Rico is forecast to continue
on a northwest track the next couple of days and is forecast to be
near the central to northwest Bahamas by Monday with an increase
in moisture and chances of showers and thunderstorms across the
region. Deep moisture and regional showers and thunderstorms could
linger into mid-week.
&&
.MARINE...
The most recent ASCAT pass at 1605Z indicated winds to near 20
knots or just above in the off shore waters mainly east of
Biscayne Bay. Some of the wind data may be rain contaminated and
some of it is on the western fringe of the pass where there is
some additional uncertainty. The wind forecast for this afternoon
and evening for the off shore waters east of Biscayne Bay is in
the 17 to 20 knot range, which could extend into Biscayne Bay as
well, and will continue with a pre-cautionary statement and do
not think a Small Craft Advisory will be necessary. Later tonight
winds in the off shore Gulf waters may near the 15 to 20 knot
range as well with a pre-cautionary statement in effect. The weak
surface low is forecast to drift westward tonight into Saturday
and the pressure gradient and winds will slowly weaken into
Saturday morning. For the remainder of the weekend winds and seas
will be well below any advisory or pre-cautionary statement
criteria.
&&
.BEACH FORECAST...
With the increased winds this afternoon across the coastal zone
of Miami Dade and Broward counties the rip current risk was
increased to a high risk for these counties and could persist
through the early morning hours on Saturday then decrease to a
more moderate risk as easterly winds continue to slowly subside
through Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 78 90 79 89 / 30 40 40 50
Fort Lauderdale 80 89 79 89 / 40 40 30 50
Miami 78 90 78 90 / 50 50 40 50
Naples 77 92 76 91 / 20 50 30 50
&&
.MFL Watches/Warnings/Advisories...
FL...High Rip Current Risk until midnight EDT tonight for FLZ172-173.
AM...None.
GM...None.
&&
$$
DISCUSSION...60/BD
MARINE...60/BD
BEACH FORECAST...60/BD
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
324 PM CDT FRI SEP 9 2016
.SHORT TERM...(This evening through Saturday)
Issued at 324 PM CDT Fri Sep 9 2016
Unorganized low pressure at the surface developing across Iowa is
expected to finally take shape and move northeast through Wisconsin
tonight. Meanwhile a deep trough is in the process of digging and
compacting aloft with its axis through the western Dakotas this
afternoon. For the remainder of the afternoon, the HRRR is on track
with an area of showers and thunderstorms advancing northeast out of
Iowa through south central MN and will continue northeast over the
next several hours, exiting our forecast area around 01-02Z.
The trough axis will continue east tonight and be
centered over Minnesota by tomorrow morning. Low level cold air
advection will progress eastward overnight as that boundary
continued its advance and that surface low moves off to out east.
Isolated showers are possible overnight thanks to the advancing
trough.
Tomorrow will be cooler and feel and look more like fall with breezy
northwest winds, lower dewpoints, and stubborn cloud cover that
could linger through the day in western WI and parts of eastern MN.
Expecting a broken cumulus field to develop given strong CAA and
saturation at the top of the channel during the day. The RAP has
been steadfast in working spits of rain and showers through under
the center of the trough as well. Eventually, low level anticyclonic
flow on the backside of the upper trough should help clouds start
scattering out from west to east. Most locations will top out in
the upper 60s tomorrow and low 70s in western MN where less cloud
cover is expected.
.LONG TERM...(Saturday night through Friday)
Issued at 324 PM CDT Fri Sep 9 2016
High pressure will be firmly overhead at the start of the long
term, then drift off to the lower Great Lakes through Monday.
Lows Saturday night will be more fall like with middle 40s to
lower 50s. However, the cooler temperatures won`t last long as we
transition to the backside of the high for Sunday with afternoon
highs in the middle 70s to lower 80s.
Good continuity remains between the GFS and EC with regards to the
passage of a cold front across the area from late Monday into
early Tuesday. Neither model is showing much precipitation as the
bulk of the forcing is north of us in Ontario. Therefore, small
chance pops continue, mainly for the eastern and southern FA.
Another large high pressure system will build in for late Tuesday
into Thursday with pleasant early fall-like weather conditions.
Highs Tuesday and Wednesday will only be in the 60s, some 5 to 8
degrees below normal. Wednesday morning will be quite cool with
lows in the upper 30s to middle 40s. As it was pointed out in the
overnight AFD, the last time MSP has had a low below 50 degrees
was May 18th. If the low below 50 degrees occurs, this would end
our streak of days where the temperature has remained 50 or
greater at 118 days, which would be the second longest such
stretch behind only the 124 days from the summer of 1881.
Weather conditions will begin to deteriorate on Friday and
persist through the weekend as a closed upper low in the northern
Rockies begins to open up and advance into the Northern Plains.
Chance pops are in place now, but they will likely trend higher as
we get closer to the event and continuity is established.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 214 PM CDT Fri Sep 9 2016
Frontal boundary working into western MN this afternoon with
northwest winds increasing through the afternoon behind it.
South or southwest wind will persist otherwise until that
boundary arrives. Still have opportunities for VCSH for much of
the area ahead of this boundary through the evening. For tomorrow,
main upper trough moves through and could bring MVFR with spits of
rain through overnight and through tomorrow morning. Then,
northwest winds get blustery and a dense cu field appears likely
for much of the day in eastern MN and western WI.
KMSP...Could see MVFR cigs early tomorrow morning, but held off for
now as confidence is low. Removed thunder as the storms along the
front in Iowa have become dominant this afternoon.
/OUTLOOK FOR KMSP/
Sun...VFR. Wind S at 10-15 kts.
Mon...VFR. Wind SW 5-10 kts turning NW.
Tue...VFR. Wind N 5-10 kts.
&&
.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&
$$
SHORT TERM...SPD
LONG TERM...RAH
AVIATION...SPD
Area Forecast Discussion
National Weather Service Mount Holly NJ
404 PM EDT FRI SEP 9 2016
.SYNOPSIS...
A very weak cold front will slide down into northeast Pennsylvania
and northern New Jersey this evening, then lift north into New York
State Saturday. A stronger cold front will move east through the mid
Atlantic states late Saturday night. High pressure then will build
eastward into the region early next week. Another cold front will
cross the mid Atlantic states late Wednesday, followed by Great
Lakes high pressure for the end of the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Record high mins occurred at all our 8 stations this morning
(XMACIS check) and record max`s occurred this afternoon at
ILG ACY GED PHL (95) and TTN (94).
A very weak cool front-or trough, slipping southeast into our area
late today may light up with activity sometime toward 23z as max
heating maximizes its light and convergence tries to drive
convection. 1000J ML Cape but weak under 25 kt 0-6KM shear
should-could result in a few gully washers in 2 to 2.25 pwat axis
(northern portion of that axis)...probably I78-I80 (RDG/ABE/TTN)
region late afternoon-evening that may slide down to PHL-ACY in
the 6 to 10 pm time frame. -5C at 500MB is a potential capping
problem, especially if we cant pool more moisture (buoyancy) along
that boundary near I80 this afternoon.
Monitoring the HRRR for convection.
Tonight...Convection (dying tstms to showers in the weakly capped
environment (-5C at 500 MB)), whatever there is...may linger into
the night near the southward sliding wind shift to just south of
KRDG-KTTN.
It should be a few degrees cooler tonight than it was this morning
when min temps were 15 to 21 degrees above normal (PHL 80, ABE 77).
Still though...about 15 above normal where rain cooled air doesn`t
bring it down a little more than the guidance fcst.
Otherwise the 330 PM fcst basis was a 50 50 blend of the 12z/9 GFS/NAM
MOS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
Hot (near record) and humid with remains of the wind shift vcnty
KRDG-KTTN drifting northward and having little or no impact on
our afternoon weather. Mentioned near record heat instead of
record, since the records are slightly higher.
The 330 PM was a 50 50 blend of the 12z/9 gfs/nam mos. The cool temp
(climo impacted as well) bias resulted in our forecasting temps
a bit warmer than guidance and may not have warmed it enough with
20c overhead.
Convection: no confidence in any thing east of the Poconos during
the day.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Sat night and early Sunday...A cold front will cross the area this
period. The hot and humid airmass will yield to much drier and
somewhat cooler air for the last part of the weekend. Temperatures
Sunday will still be above normal, with low 80s north and mid 80s
south/east. Winds Sunday will be a bit gusty with NW breezes at
12- 18 mph during the afternoon.
Sunday afternoon thru Tuesday night...A dry period with high
pressure building in. Temperatures will be normal Mon and above
normal for Tue with readings in the low/mid 80s Tue. We could end up
being a bit warmer Tue/Tue night if present trends in model guidance
continue.
Wed/Wed night...Another cold front is expected to cross the area. We
have continued with the chc pops for a tstm on Wed and then taper
back to slgt chc for Wed night.
Thu/Fri...Temperatures back to normal, or slightly below with
another high pressure system expected to build over the area. Dry
weather is expected.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Rest of today...VFR sct-bkn aoa 5000 ft. there may be a brief IFR
tstm vcnty KRDG,KABE,KTTN in the 21z-01z/10 time frame? west to
southwest wind gust 15 kt.
Tonight...VFR sct-bkn aoa 5000 ft. Any lingering (isolated?) thunderstorms
to the north of KPHL during the evening should die as a shower or
sprinkle near KPHL around 06z. winds light southwest...possibly
trending light north or northeast late at KABE/KRDG/KTTN.
Saturday...Mainly VFR with sct clouds aoa 5000 ft. Winds becoming
southwest gusty 15 to 20 kt during the afternoon.
OUTLOOK...
Saturday night and Sunday: Mainly VFR, Southwesterly winds shifting
to west or northwesterly around 10-15 knots with higher gusts.
Isolated showers and thunderstorms may lower ceilings and
visibilities for brief intervals Saturday night.
Sunday night through Tuesday: VFR, with winds 10 knots or less.
Wednesday...Mostly VFR, but sct thunderstorms are possible.
&&
.MARINE...
Winds and seas should remain below SCA criteria through midday
Saturday.
SCA issued thereafter for the Atlantic waters and may need to add
DE Bay in later forecasts. We could be several hours premature
but thinking that sw winds in the increasing gradient should
produce afternoon gusts to 25 kt on the near shore waters.
OUTLOOK...
A small craft advisory was been issued for the ocean zones through
Sunday morning. This could be extended later in time Sunday as
the cooler air arrives. Winds and seas will remain below SCA
levels in Del bay. Sct tstms may create locally higher winds and
seas. Sat night and early Sunday.
Sun afternoon thru Wed...Mostly sub-sca conditions expected. A few
tstms are possible later Wed.
RIP CURRENTS...Moderate risk along the NJ coast continues this
afternoon. Increasing ese swell to near 3 ft and 9 seconds this
afternoon, combined with an expected wind shift to south certainly
results in low enhanced but may migrate up to a moderate risk this
afternoon. So its hot and inviting to jump into the surf... but be
careful. I`d only swim in the presence of a lifeguard, to ensure
my weaker swimmer safety.
Saturday: The probable risk for the formation of dangerous rip
currents is moderate.
&&
.CLIMATE...
Heat (4-6 day heat wave) in progress as we go through this week.
Heat wave count as of today: ILG 4 days; PHL ABE RDG 3 days, so far.
9/7: RER equaled at ABE.
9/8: RERGED and a RERTTN equal.
9/9: RERACY, GED, ILG, PHL (95) and TTN (94) so far today for max`s
and for all 8 climate sites on the mins. rer`s will update by 545 PM.
Here are the record high temperatures for Today and Saturday, the
hottest days in this stretch.
Friday- 9/9 Saturday 9/10
ACY 92-1915 95-1983
PHL 94-1884 97-1983
ILG 94-1939, 1915 98-1983
ABE 95-2015 96,1983
TTN 93-1959 101,1983
GED 92-2015,1985 93,1985
RDG 94-2015, 1959 100,1983
MPO 88-1964 89,1983
So far Philadelphia International Airport has recorded 43 days
where the high temperature has gone over 90 degrees this is sixth
all time. Several other years had more days over 90 degrees they
include 2010 with 55 90 degree days and 1991 with 53 90 degree
days. Additional years include 1995 and 1988 with 49 days over 90
degrees and 46 days back in 2002. A few more 90 degree days are
still likely to occur this week, another 90 degree day possible
next Wednesday.
The table below for reference
RER # 90 deg days: Season total, Season RER, Sept rer, Sept mean then
closing out with Season rank and POR. You can see in the period of
record (POR) that the number of 90 degree days this year will be
top 5 in the detailed historical record, further supporting one
of the warmest summers in the period of record.
The 90 degree data below is through today - September 9.
2016 RER 9/RER 9/Mean Season rank POR
ABE 36 41-1966 7-2015 1 #4 prob rise to #2-3 1922
ACY 31 46-2010 9-1961 1 #6 now could tie #4 1874
PHL 44 55-2010 8-1970 2 #5 1872
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 7 PM EDT Saturday for PAZ060>062-070-071-
101>106.
NJ...Heat Advisory until 7 PM EDT Saturday for NJZ009-010-012-013-
015>023-027.
DE...Heat Advisory until 7 PM EDT Saturday for DEZ001>003.
MD...Heat Advisory until 7 PM EDT Saturday for MDZ008-012-015-019-
020.
MARINE...Small Craft Advisory from noon Saturday to 5 AM EDT Sunday for
ANZ450>455.
&&
$$
Synopsis...O`Hara
Near Term...Drag 402
Short Term...Drag 402
Long Term...O`Hara
Aviation...Drag/O`Hara 402
Marine...Drag/Gaines/O`Hara 402
Climate...402
Area Forecast Discussion
National Weather Service Blacksburg VA
317 PM EDT Fri Sep 9 2016
.SYNOPSIS...
A stationary front extended across the Ohio Valley to a low in
Nebraska. This low will move northeast tonight and Saturday and
will push a strong cold front through the area on Saturday night
and Sunday. A cold front will move into and through the region
late Saturday night into Sunday. Behind this front, a large area
of high pressure will cover the region Monday and Tuesday.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 315 PM EDT Friday...
Forecast area will remain in air mass with unseasonable warm
temperatures tonight and Saturday. 850 temperatures Saturdayafternoon
will again be 20-21C. May have more high clouds in the west
Saturday afternoon from upstream showers and thunderstorms. Have
gone warmer than MAV guidance, especially in the east on Saturday.
Local WRF takes the showers and thunderstorms in central Kentucky
into the northern county warning area after 4PM but this looks
overdone compared to all other Hi-Res models. Have made slight
adjustments to lower probability of precipitation from Bluefield
WV to Lexington VA.
Timing of the front of Saturday brings chance of showers and
thunderstorms into the western mountains. 12Z Hi-Res along with
some other ensemble guidance were hinting at isolated
thunderstorms along the southern Blue Ridge tomorrow afternoon.
Will leave most of the area dry for now.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
As of 305 PM EDT Friday...
We start the period with an upper level trof moving through the eastern US and
pushing a cold front through the Appalachians and central mid Atlantic region.
The front is expected to have some activity with it upstream but by the time it
moves through our area on Saturday night, the lack of diurnally driven
instability will combine with winds shifting around to a northwesterly
downslope direction to suppress shower activity for the majority of the area.
Chance POPs for scattered showers/storms far west of the Blue Ridge should
cover the situation.
Quasi zonal upper flow is then expected through the first part of next week
with some shallow, broad ridging east of the Mississippi. This will result in
the frontal boundary washing out just off to our south and east as a large area
of high pressure builds eastward and ultimately wedges down the eastern slopes
of the Appalachians. Expect a chance for showers/thunder on Sunday mainly
across NC and into the eastern piedmont/Southside VA with the lingering front,
then setting up with slight chance POPs along the west/south/east wedge flanks
and maybe a sprinkle from the NC mountains up into the southern Blue Ridge.
Cooler temperatures will be slow to move in behind the front so Sunday still
looks to be several degrees above normal with mid/upper 80s east of the Ridge
and mid/upper 70s west. By Monday highs will be a bit cooler with lower 80s
east to mid/upper 70s west.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 305 PM EDT Friday...
For most of next week, the upper pattern will feature a progressive and low
amplitude regime with a cutoff low developing over the western US. This will
inhibit deep moisture transport into the region and continue to limit our
chances for any significant widespread rainfall.
Surface high pressure over the New England coast will drift into the Atlantic
on Tuesday and start to bring winds around to a southeasterly direction. This
will keep a chance for scattered showers/storms in the forecast mainly from the
southern Blue Ridge into the mountains of North Carolina primarily due to
orographic forcing. Another front will be approaching form the north/northwest
on Wednesday but once again looks to be losing steam as it moves in, so
slight/low chance POPs will cover the situation for now. Behind the front, a
large area of high pressure will once again build in from the Great Lakes and
eventually set up a wedge for the end of the week with slight chance POPs from
the Ridge westward.
Temperatures through midweek will be warm as they run several degrees above
normal with mid/upper 80s east to upper 70s/lower 80s west. Behind the front,
we can expect cooler readings for the end of the week with upper 70s east to
middle 70s west.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
As of 115 PM EDT Friday...
Models continue to show the axis of deeper moisture ahead of
a stationary front from southern New York to northern Ohio.
Scattered showers and thunderstorms south of this front will
track from central Kentucky into northern West Virginia this
afternoon and evening. Only a low probability of any of these
storms impacting KLWB so have left it out of the TAF. This is
supported by the last few runs of the HRRR and RAP as well as
other Hi-Res guidance. So conditions will remain VFR for the rest
of the day across southwest Virginia and southeast West Virginia.
Medium confidence as to the development and expect of fog again
tonight. Have only a couple hours with MVFR visibilities late at
KLWB/KBCB.This will depend on how much mid and high debris cloud
come in to the area from storms to the west.
Showers and thunderstorms are expected along a stronger cold front
on Saturday but high confidence this will not reach the
Appalachians until after the 18Z end of the TAF forecast period.
The timing of this front and the associated precipitation has been
very consistent in the guidance for the past several cycles.
Extended aviation discussion...
The vast majority of the period through Tuesday will be VFR.
Some localized sub- VFR ceiling may accompany the front along
with better organization of showers late Saturday night mainly
over the western mountains. Models however do not offer a lot of
hope that the precipitation will survive east of the mountains
unless coverage redevelops east of the Blue Ridge Sunday
afternoon which remains possible. KLWB and KBLF are the most
likely locations to have any sub VFR conditions Saturday night.
KDAN has a low probability of precipitation Sunday afternoon and
evening.
This front moves south of the area Sunday night and Monday with
potential for a wedge to setup and bring an east to northeast flow
of lower clouds into the area, so sub-VFR conditions may exist early
next week, especially along the eastern slopes of the Blue Ridge
Monday night into Tuesday.
&&
.CLIMATE...
Record high temperatures for Friday (9/9)...
Roanoke......98 (1939)
Lynchburg....98 (1900)
Danville.....95 (2007)
Blacksburg...90 (2007)
Bluefield....90 (2007)
Record high temperatures for Saturday, Sept. 10...
Roanoke......97 in 1983
Lynchburg....98 in 1900
Danville.....95 in 2007
Blacksburg...90 in 1983
Bluefield....88 in 2013
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...MBS
LONG TERM...AMS/MBS/RCS
AVIATION...AMS/JH
CLIMATE...AMS/JH
Area Forecast Discussion
National Weather Service Shreveport LA
404 PM CDT FRI SEP 9 2016
.DISCUSSION...
Sct convection has expanded across much of SE TX this
afternoon...as well as portions of Deep E TX...with the convection
more isolated over Wrn and Ncntrl LA and Union County AR.
Evidently...the drier air to the E and N of the upper low just off
the TX coast has really tapered development over Nrn LA...with the
latest HRRR suggesting the convection diminishing by 01Z over
these areas. Have maintained slight chance pops through early
evening for these areas...with a mostly quiet night expected as
warm and muggy conditions continue over the area. However...the
afternoon water vapor imagery reveals an upper trough translating
SE across the Nrn and Cntrl Rockies...which will absorb the weak
upper troughing /the remnants of Newton/ over the TX Panhandle
into NW OK/Cntrl KS/...allowing a weak cold front to shift SE into
NW TX/Cntrl and Ern OK late tonight. A 25-30kt SSW LLJ is progged
to develop over the Srn Plains ahead of the front later
tonight...enhancing low level convergence and resulting in
sct/numerous areas of convection development along/ahead of the
front and attendant upper trough. The short term progs suggest
that this convection will accelerate SE into Wrn AR/extreme SE
OK/Ncntrl TX late tonight...reaching the far NW zones just prior
to daybreak Saturday. Have maintained chance pops NW of I-30
tonight...with the progs maintaining this convection along a SE
building mesoscale bndry through mid-morning Saturday before
weakening as pre-frontal convergence weakens when the H925-850
winds quickly become WNW.
This bndry will likely focus additional sct convection development
with diurnal heating Saturday afternoon mainly over E TX/N LA near
the I-20 corridor...with the bndry possibly hanging up over these
areas. Meanwhile...the weak cold front itself will slowly drift SE
into extreme NE TX/SW AR by mid to late morning...and should not
focus much in the way of deep convection as the air mass should be
stabilized with the earlier bndry passage/rain-cooled air. Given
the weak forcing/shear and uncertainty of additional development
for the afternoon...have lowered pops to mid and high chance
Saturday afternoon...with the convection likely diminishing during
the evening with the loss of heating/instability. The front itself
remains progged to continue drifting S and becoming stationary
Sunday over Cntrl LA/adjacent E TX...with the drier air lagging
the front a ways to the N over SW AR Sunday morning before slowly
mixing SSW for the afternoon. Sct convection should again
redevelop near the old front Sunday mainly over SE and Deep E
TX/Cntrl and Srn LA...with dry advection farther N inhibiting much
development along the I-20 corridor. Should begin to see more
comfortable temps during the morning mainly over SE OK/SW AR
Saturday and especially Sunday nights...offering another brief
tease of Fall for these areas.
Additional drier air is progged to backdoor SW into Ncntrl LA
Sunday night behind the old sfc bndry...with any convection
possibly more isolated over our Srn counties and parishes.
Meanwhile...the TX coastal upper low appears as if it will be
absorbed in the weak troughing by Sunday...lingering near the SE
TX/S LA coasts through Monday before ridging aloft builds and
expands E across the Srn Plains and the Ark-La-Tex. Thus...a
return to near to slightly above normal temps is expected by
Monday through much of next week. ENE sfc winds behind weak sfc
ridging appear to persist through much of next week...resulting in
slightly cooler min temps through the period. Much of the week
should remain dry beneath the upper ridge...although isolated
convection can/t be ruled out mainly over the Srn and Wrn zones
as the ridge begins to slowly nudge E into the Lower MS Valley.
Prelims to follow below...
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&&
.PREV DISCUSSION... /issued 1204 PM CDT FRI SEP 9 2016/
AVIATION...
Sct shwrs ongoing across portions of the region from near KLFK to
KELD will continue through around sunset, with some addition of
tstms later this aftn. VFR conditions expected to prevail through
much of the pd, with some tempo IFR/MVFR cigs possible once again
just after sunrise. Cold front/associated tstms will approach
from the nw Saturday morning and push slowly swd through the day.
Have handled this possibility with VCTS for now, with the front
making it to near a KTYR/KELD line by the end of the 18Z TAF pd.
/12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 75 91 70 88 / 20 50 20 20
MLU 74 92 71 87 / 20 40 30 30
DEQ 72 85 61 86 / 40 60 10 0
TXK 74 87 65 86 / 20 60 10 0
ELD 74 88 67 85 / 20 50 20 10
TYR 75 89 69 88 / 20 50 20 20
GGG 74 90 69 88 / 20 50 20 20
LFK 73 91 72 90 / 20 40 30 40
&&
.SHV Watches/Warnings/Advisories...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
15