Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/25/16
Area Forecast Discussion
National Weather Service Albany NY
920 PM EST Thu Nov 24 2016
.SYNOPSIS...
A weak low pressure system will slowly track eastward
across the northern Great Lakes region into southeast Canada
overnight into tomorrow bringing some light drizzle,rain snow. A
stronger disturbance will move through late Friday into Saturday,
bringing valley rain showers and mountain snow showers. Mostly
cloudy and cool conditions will persist through much of the
holiday weekend.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 920 PM EST...The KENX radar indicates little organized pcpn
over the forecast area, except for some light rain and snow near
the lake George Region into southern VT. However...some patchy
drizzle is setting up over central NY spreading into eastern NY.
The short-wave trough axis has moved downstream over New England
with a weak secondary low forming near eastern NJ and south of
Long Island. Also some weak mid level ridging is building into
western NY and PA. Plenty low-level moisture will be trapped under
an inversion and it is very saturated below 700 hPa based on the
00Z KALY sounding. Temps are generally in the 30s across the
forecast area. Some upper 20s and lower 30s are across portions of
the Mohawk Valley...southern Adirondacks...the Lake George
Saratoga Region and southern VT.
Temps are not going to move much tonight with the saturated
atmosphere. Model soundings show little ice in the clouds...and
some drying aloft. There will be a chance or slight chc of drizzle
or freezing drizzle depending on the surface temps especially
after midnight. The latest HRRR and NAM shows little pcpn after
midnight. We will address the patchy freezing drizzle for the
overnight period with a Special Weather Statement which is in
agreement with the neighboring offices /WFO`s BGM...BOX...and
BTV/. Also patchy fog was added to the forecast grids everywhere
after midnight.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
Spotty light mountain snow and valley rain will continue through
much of the evening, as the upper level short wave trough axis
moves across the area. Then around or shortly after midnight, as
the trough pulls away and ice nuclei are lost in the clouds, we
may have some drizzle or pockets of freezing drizzle where surface
temps cool to around or slightly below 32F. It appears valley
locations from the Capital District southward will have temps
remaining just above freezing, but the higher terrain areas and
upper Hudson Valley will be cold enough for patchy freezing
drizzle. Will continue to mention this in the HWO.
A stronger and more progressive short wave trough will be moving
eastward across the Great Lakes Friday into Friday night, bringing
scattered to numerous snow and/or rain showers to the region. Best
chances for measurable snow will be for the higher terrain areas
north of I-90 and mainly Friday night into Saturday. Thermal
profiles indicate mainly snow or a snow/rain mix for the higher
terrain and rain for the valleys initially on Friday. Rain showers
could mix with some wet snow in the valleys late Friday night into
Saturday morning as colder air aloft moves in. Most of the precip
should occur Friday afternoon and night as cyclonic vorticity
advection increases ahead of the approaching trough. Temps should
be closer to normal with a southerly flow developing in the
boundary layer ahead of the trough.
On Saturday, the upper level trough will settle in across the
Northeast, with the center of the low positioned over southern
Quebec. A moist northwest flow will result in mainly isolated to
scattered rain/snow showers continuing Saturday into Sunday
morning. The best chance for measurable precip will be across the
western Adirondacks due to upslope flow and also the Mohawk Valley
and eastern Catskills where some lake enhanced snow showers are
possible due to 300-310 mixed layer flow and conditional lake
induced instability developing. Any accumulations will be light
though, as boundary layer temps will be borderline for rain/snow,
especially during the daylight hours.
There may be some clearing Sunday afternoon and evening as the
upper level trough shifts into New England and heights begin to
rise.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A fairly active and highly amplified pattern for the long term which
will keep lots of clouds and the chances for precipitation through
much of the period.
The exception to this will be through Sunday night and Monday as
large upper low and northwest flow regime from the past few days
begins to lift northeast allowing for ridging at all levels to build
across the I95 corridor and into the northeast. This will likely be
the best potential for some sunshine as the remainder of the week is
much less so...
A storm developing across the center of the nation Monday will carve
out a deep trough and begin to spread moisture from the Gulf of
Mexico northeastward into the northeast. While temperatures will be
moderating as H850 temperatures moderate close to +10c, surface
temperatures should slowly moderate through early next week. With
this increase in moisture will also introduce the chance for mainly
rain (some wintry mix possible in normally cooler locations at the
onset of the precipitation). Then some discrepancy with respect to
the potential mid week storm. While confidence that precipitation
will be in a liquid form, there are timing differences with the
short wave rounding the base of the deep trough with the GFS/GGEM in
close agreement with the storm impacting the region Wednesday with
the ECMWF about a day behind. For now, we will retain the high
chance PoPs and above normal temperatures under considerable cloud
coverage.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
A primary low continues to weaken over western NY with a
secondary wave forming near the NJ coast. Light mixed pcpn ahead
of the double barrel system continues to impact eastern NY and
western New England early this evening with predominately rain and
snow...though some spotty sleet has also occurred.
Conditions are mainly MVFR with spotty IFR especially for KPSF
early this evening. KPOU continues to have VFR conditions. The
boundary layer continues to be saturated. There is plenty low-
level moisture and expecting widespread IFR/MVFR conditions. The
best chc of IFR CIGS/VSBYS with patchy drizzle overnight will be
KALB/KGFL/KPSF. For now have kept conditions in the MVFR level at
KPOU. There maybe some patchy freezing drizzle but was not
confident enough to add to the TAFS possibly at KGFL/KPSF.
CIGS/VSBYS will be stubborn to rise quickly from IFR/low MVFR
levels tomorrow morning with all the low-level moisture trapped in
the boundary layer. Increased KPOU first to VFR levels by 19Z/SUN.
Have slowly increased CIGS to MVFR levels at KALB/KGFL/KPSF at
2-2.5 kft AGL between 18Z-20Z.
The winds will be light and variable at 3 kts or less or calm
overnight into the late morning. A light south to west wind of
close to 5 kts is possible by the early afternoon at the TAF
sites.
Outlook...
Friday Night: Moderate Operational Impact. Chance of RA...DZ.
Saturday: Moderate Operational Impact. Chance of RA.
Saturday Night: Slight Chance of RA...SN.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Chance of RA...SN.
&&
.FIRE WEATHER...
A weak low pressure system will slowly track eastward across the
Great Lakes region through tomorrow, bringing a light wintry mix
to the region. A stronger disturbance will move through late
Friday into Saturday, bringing valley rain showers and mountain
snow showers. Mostly cloudy and cool conditions will persist
through much of the holiday weekend.
&&
.HYDROLOGY...
Some rain, snow or wintry mix will continue this evening into the
overnight period. The precipitation will be light and have no
impact on rivers and streams. Continued chances for snow/rain
showers linger through much of the holiday weekend, with very
little change in river/stream levels expected.
A few inches to over a foot of snow depth has built up across
many higher terrain locations from this past weekend into early
this week. Only gradual melting is expected, as temperatures will
continue to be below freezing each of the next several nights,
with daytime highs mainly in the 30s.
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...JVM/Wasula
NEAR TERM...Wasula
SHORT TERM...JVM
LONG TERM...IAA/BGM
AVIATION...Wasula
FIRE WEATHER...JVM
HYDROLOGY...JVM
Area Forecast Discussion
National Weather Service Houston/Galveston TX
843 PM CST Thu Nov 24 2016
.DISCUSSION...
The remnants of Tuesday`s cold front has either become stationary
or is slowly returning north as a warm front. Either way, it is
serving as a focus for a few showers and thunderstorms over the
Gulf. Should continue to get additional showers and thunderstorms
tonight as the boundary slowly moves north. Cloud cover should
increase and thicken in advance of the coastal boundary so min
temps should be warmer than last night and probably a degree or so
above guidance. Other than some minor tweaks to sky grids and
hourly temps, the previous forecast looks on track. 43
&&
.PREV DISCUSSION... /ISSUED 524 PM CST Thu Nov 24 2016/
AVIATION...
Moisture return was evident on satellite from South Texas up to
the Matagorda Bay area. The latest high res models bring a hint of
MVFR and for now will only introduce a few to scattered deck. SREF
fog probabilities show the best potential for MVFR fog to be over
KSGR and KLBX with a slighter possibility at KCXO - all between
09Z and 15Z. The latest HRRR model shows the rain potential
increasing for KLBX, KSGR, and KGLS Friday afternoon.
40
PREV DISCUSSION... /ISSUED 348 PM CST Thu Nov 24 2016/
DISCUSSION...
Some fog and/or light showers are possible to the southwest of
Houston tonight into tomorrow, but the main story this forecast
period will come with the next front Monday into Tuesday. After
that, there are significant model differences in how much push the
front will have beyond the area for the mid to late week.
Rest of today through Friday night...
Per satellite, clouds are returning mainly to the southwest of
the area, but over time should creep up. Along with that, some
progged weak isentropic lift, as well as the remnants of the old
cold front, shoved back northwards over the area, looks to
generate showers through this period. The best chance for rain
looks to center over the Matagorda Bay area early Friday morning,
but have PoPs in place from tonight into Friday afternoon as there
is a fair amount of uncertainty among the guidance as to when
these showers will precisely pop up. Otherwise, the increased
moisture and cloudiness should keep low temperatures up tonight
over last night, but as northerly winds reinforce drier air, we
should get cooler again Friday night. Lingering clouds will keep
things from crashing, but a drop of 5-10 degrees seems reasonable.
The weekend...
A generally dry weekend should be expected as a surface high moves
through the area and we sit under ridging aloft. Saturday looks to
be on the cooler side, but as onshore flow emerges for Sunday,
expect a trend upwards in temperatures. Depending on how
progressive the next low/front is, cloudiness is expected to
increase across the area and some showers may begin to emerge in
the west Sunday night. But ultimately, the theme of the weekend
will be fair weather with a warming trend.
Monday through Wednesday...
The next frontal passage looks to come early next week, with
generally good agreement in the front reaching SE Texas Monday
night. Along with that is a pretty good chance at rain,
particularly in the north. As you head southwest, the potential
for dry slotting reduces confidence in rain chances somewhat.
However, there is a pretty favorable dynamic structure for severe
weather, and forecast hodographs show good low level curvature.
Above that, shear is boosted by the jet structure, though the
hodograph is somewhat hampered by more unidirectional shear. The
concern may be thermodynamic, as forecast soundings around the
area do show a weak cap. But if the timing pans out, forcing could
overcome that, so the area outlined in SPC`s Day 3-8 outlook seems
reasonable.
After that, guidance begins to diverge wildly, particularly
between the GFS and the Euro. The GFS is much more progressive,
digging a deeper upper trough eastward into Texas and drying
things out behind the front. The Euro, on the other hand, lifts a
weak trough up to the Great Lakes, while digging a deeper trough
over far West Texas. At the surface, the front does not clear
significantly, and shows the emergence of a coastal trough that
gets pushed back over the upper Texas coast, and keeps the rain
going into the midweek. Have basically taken a middle path with
the forecast, or in terms of Thanksgiving football - sent out the
punt team in hopes the defense can get us the ball back with good
field position.
Luchs
MARINE...
Winds have relaxed as expected this afternoon and seas subsiding.
Another weak cold frontal should move offshore Friday evening with
light-moderate winds in its wake. A warm front swings north through
the region Sunday with moderate southerly flow becoming strong on
Monday. Seas may build to greater than 8 feet with the long fetch
and period of strong southerlies ahead of the lead upper system. A
Pacific cold front sweeps through late Monday but probably (models
differ greatly) what have a strong push given the upper trough`s
slow eastward evolution. The front may become stationary over the
Coastal waters Tuesday with shifting winds through early Wednesday
before the colder air arrives. Small craft advisories will be a
certainty for Monday and the large long period swells may cause some
elevated tide levels and hazardous rip currents.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 56 70 47 68 52 / 10 20 10 10 0
Houston (IAH) 57 73 50 70 52 / 10 20 10 10 0
Galveston (GLS) 64 70 58 68 62 / 10 30 0 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Discussion...43
Area Forecast Discussion
National Weather Service Lincoln IL
912 PM CST Thu Nov 24 2016
.UPDATE...
Issued at 912 PM CST Thu Nov 24 2016
Main story for central Illinois tonight will be a persistent
blanket of clouds, with light west or variable winds. A weak
shortwave moving across Iowa early this evening will progress
across northern Illinois overnight. Light rain or snow showers
associated with that wave should remain north of our forecast
area. However, the abundance of low level moisture in central
Illinois could be enough to support spotty drizzle or sprinkles
north of Rushville to Lincoln to Champaign/Danville. Will lean on
the high resolution guidance pointing toward keeping the primary
forcing for precip north of us and keep a dry forecast in central
Illinois overnight. Radar images are showing some returns
expanding into Knox and Stark counties in the last hour, with a
band of light showers extending from Des Moines Iowa to Dubuque
IA, sliding eastward. HRRR and RAP guidance dissipates the
southern portion of that line with time, supporting our dry
forecast tonight.
Temps may remain slightly warmer than guidance numbers tonight,
based on overcast conditions and dewpoints in the mid 30s across
the area and upstream. Nudged the lows up slightly. No other
changes appear necessary this evening. Updated forecast info is
already available.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 159 PM CST Thu Nov 24 2016
Expansive stratocumulus shield has started to erode over central and
western Missouri this afternoon. With the ridge overhead at the
moment, there are some doubts that this clearing will make it all
the way over here, as LAPS soundings still show a decent inversion
around 900 mb and RAP 925 mb humidity plots are pretty solid through
the night. So, will maintain the cloudy forecast overnight, followed
by some slow clearing on Friday once the upper wave currently over
the Dakotas passes by. With a bit of sunshine, temperatures should
get a little warmer on Friday, mainly mid to upper 40s with some 50
degree readings over the far southwest and southeast parts of the
CWA.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 159 PM CST Thu Nov 24 2016
Dry weather is expected the first part of the weekend as a
surface high pressure ridge moves across the area. As this high
pressure moves east into the southeastern US, a strong weather
system developing in the western plains will move out into the
plains and move northeast into the northern plains. The end of a
warm front should lift across a portion of central IL Sunday
afternoon and could bring showers to the western parts of the CWA.
As the main low pressure area lifts into the northern plains, warm
moist air will stream northward into the area the latter part of the
weekend and into the beginning of next week. This will cause
occasional showers across the area beginning Sunday night. There
could be a brief break in the precip Monday morning in the wake of
the first wave, but with models differing on how fast to bring the
secondary system into the area, will keep chance pops for Mon
morning. By Monday afternoon, the secondary system will lift out the
plains and bring heavier rain and rain showers to the most of the
CWA Monday afternoon through Monday night. Heavy rainfall will be
possible with this secondary wave, with around an inch possible in
southeast Illinois Mon afternoon through Mon evening. Moderate
rainfall will be possible north of this area over most of central
IL, with rainfall amounts exceeding over one half inch. Rain showers
will remain possible through Tuesday as the surface system pulls
away and the upper level system slowly moves northeast toward
Canada. Beyond this system, the ECMWF and GFS differ on if the area
will be dry or if there will be more showers somewhere in the area.
The ECMWF is showing more showers for the southeast Wed night, while
the GFS is dry. For now, will keep dry forecast since that is what
the ECMWF showed previously.
Temps will become unseasonably warm for the weekend and into the
beginning of next week as the main surface system stays to the west
and warm air is advected into the area. High temps are expected to
reach into the upper 50s to near 60 for Mon and Tue. Then temps will
drop back down to more seasonable levels for Wed and Thur.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 556 PM CST Thu Nov 24 2016
Widespread MVFR stratocumulus deck will continue much of the
forecast period. The back edge of the clouds was clearing across
Missouri toward the IL border this afternoon. However, the
clearing progression stopped after 4 pm, and little additional
eastward clearing is expected. A pronounced inversion should
intensify as the ground level airmass cools this evening.
Forecast soundings are pointing toward little clearing all the way
through tomorrow morning. Cloud ceiling heights should climb
toward VFR toward 18z, with some clearing of the clouds from SW to
NE as the afternoon progresses. Therefore, keeping MVFR conditions
tonight and at least through around midday on Friday.
Winds will remain NW through the entire TAF period, with speeds
prevailing below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Geelhart
LONG TERM...Auten
AVIATION...Shimon
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
526 PM CST Thu Nov 24 2016
.SHORT TERM... (Through Late Friday Afternoon)
Issued at 258 PM CST Thu Nov 24 2016
Satellite imagery late this afternoon is showing that clouds are
eroding on the back side of the surface ridge across central
Missouri. This trend will likely continue to at least just west of
the Mississippi River before sunset when mixing ceases for the day.
Then RAP soundings are showing the low level profiles moistening
back up beneath 850mb overnight. This is part due to the area of low
clouds currently over Nebraska and northern Kansas ahead of a upper
trough moving across the northern Plains. This trough will move
across the Midwest bringing the moisture with it. Will go with
mostly cloudy to cloudy skies everywhere overnight before skies
clear out on Friday as drier air advects in from the northwest.
Should not be much drop in temperatures tonight with clouds holding
in place. Went warmer than MOS guidance in most locations. Clouds
will break out tomorrow morning helping highs climb to near GFS
MOS and SREF mean highs.
Gosselin
.LONG TERM... (Friday Night through Next Thursday)
Issued at 258 PM CST Thu Nov 24 2016
(Friday Night - Saturday Night)
An area of high pressure at the sfc will slide eastward from the
south-central Plains to near the confluence of the Ohio and
Mississippi Rivers by Saturday morning. This area of high pressure
will be accompanied by light winds and a clear sky...promoting a
good radiational cooling setup. Lows are expected to range from the
mid 20s to near freezing with the coldest conditions across the
eastern Ozarks. Favored cooler MET guidance for lows Friday
night...and even went a few degrees cooler than that for favored
terrain where model guidance has had a warm bias under similar
circumstances this fall.
As sfc high continues to slide predominantly eastward...southerly
return flow should be in full earnest by Saturday afternoon.
Temperatures should be 5+ degrees warmer on Saturday compared to
what is forecast for tomorrow. Look for highs in the 50s which is
back above normal for late November.
Lows on Saturday night will also be quite a bit warmer than the
previous night...mainly due to southerly sfc winds staying up around
5 knots all night long. Lows back above normal...and above the
freezing mark...are forecast areawide.
(Sunday - Next Thursday)
More active weather pattern will take shape for the end of the
weekend and into the next work week. Mid-Mississippi Valley will be
beneath southwest flow aloft with at least a couple of impulses
ejecting out of the longwave trough centered near the lee of the
Rockies. Two distinct rounds of rainfall are expected...one on
Sunday night with the highest chances across northern sections of
the CWFA...and the other Monday afternoon/night mainly for the
southeastern half of the CWA. Nothing that looks overly concerning
this far out in terms of hazardous weather. In fact...most parts of
the CWA have been running below to much below normal in the rainfall
department since the start of autumn. Therefore...a round or two of
widespread rainfall would actually be welcome from a hydrological
perspective...particularly for portions of southeast Missouri.
Temperatures will start off the period above normal and stay that
way through Tuesday. Temperatures are forecast to drop back to near
normal for Wednesday and next Thursday behind the second wave of
rainfall.
Gosselin
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 526 PM CST Thu Nov 24 2016
Tricky ceiling forecast this evening as an area of clearing has
moved through COU and has stalled just to the west of
UIN/SUS/CPS/STL. Expect this clearing line to remain just west of
these terminals through the overnight hours, thus MVFR cigs will
persist. Cloud bases will be a couple hundred feet on either side
of 2000 through much of the overnight. While COU has gone VFR for
now, expect another area of MVFR cigs to build in overnight. All
cigs should scour out through the day on Friday as drier air
invades from the west.
SPECIFICS FOR KSTL:
Clearing has stalled just to the west, thus expect MVFR cigs to
persist through the overnight hours. Cigs will hover near 2000
feet through much of the overnight hours. Clearing will slowly
occur through the afternoon tomorrow as drier air attempts to
build in from the west/northwest.
KD
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Midland/Odessa TX
945 PM CST Thu Nov 24 2016
.DISCUSSION...
Latest sfc analysis shows the cold front continues moving south
thru the Permian Basin, but not yet having much effect on temps.
Latest NAM and HRRR runs suggest precip development over the lwr
Trans Pecos will not develop until after 06Z. Mesoanalysis shows
very little instability in place there, and suggests removinf
thunder from the grids. We`ll do a quick update to reflect these
changes, and adjust other parameters as necessary. We`ll leave the
warning for KGDP gap winds in place. Updates out shortly.
&&
.PREV DISCUSSION... /issued 528 PM CST Thu Nov 24 2016/
DISCUSSION...
See the 00z aviation discussion below.
AVIATION...
VFR conditions are mostly expected for the next 24 hours although
there may be some low ceilings that come close to FST. Winds will
continue to shift to the north this evening as a cold front moves
into the area. Winds will become elevated and gusty out of the
north to northeast overnight then weaken and come around to the
east Friday afternoon. There is also a slight chance of showers
and isolated thunderstorms tomorrow for all terminals except HOB
and CNM.
PREV DISCUSSION... /issued 203 PM CST Thu Nov 24 2016/
DISCUSSION...
First of all we want to wish everyone a Happy Thanksgiving from NWS
Midland/Odessa! Get out and enjoy as temperatures have risen
mostly into the 60`s and 70`s this afternoon.
A shortwave moving across the Plains will send a cold front through
the area tonight ushering in cooler conditions for Friday. The front
will also bring strong gap winds through Guadalupe Pass tonight into
Friday morning. This will be a fairly minimal event, but winds will
likely reach criteria nonetheless. We have upgraded the watch to a
High Wind Warning with northeast winds peaking around sunrise Friday
morning and lessening through the day. Weak isentropic lift is still
expected to develop behind the front tomorrow. This will lead to
cloudy conditions with a chance for showers across mainly the
southern half of the region. QPF looks fairly light with most
locations receiving less than a quarter inch of rain. Clouds and
weak CAA will keep temperatures down mostly into the 50`s tomorrow
afternoon.
Upper ridging builds in this weekend in advance of the next upper
trough moving into the West. Temperatures will warm slightly
Saturday to near normal and then well above normal Sunday as
southwesterly sfc flow increases. Dry conditions are expected
through the weekend, which combined with strong winds, may
increase the fire danger Sunday. As the upper trough moves into
the Plains it will send another shot of cooler air south across
the area Monday. The models differ on the evolution and deepness
of the trough so will keep any precip chances low for now. It does
appear that temperatures will remain cool next week with yet
another front expected around Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 44 58 44 63 / 10 20 30 10
Carlsbad 36 56 39 61 / 0 10 10 0
Dryden 54 58 49 60 / 30 50 20 10
Fort Stockton 47 53 44 64 / 10 30 20 10
Guadalupe Pass 39 47 39 57 / 0 20 10 0
Hobbs 37 55 39 58 / 0 10 10 0
Marfa 38 53 37 62 / 10 20 10 10
Midland Intl Airport 45 57 43 63 / 10 20 30 10
Odessa 45 56 43 62 / 10 20 30 10
Wink 43 57 43 62 / 10 20 20 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...High Wind Warning until 11 AM MST Friday for Guadalupe Mountains.
&&
$$
80/44
Area Forecast Discussion
National Weather Service Paducah KY
600 PM CST Thu Nov 24 2016
.UPDATE...
Issued at 542 PM CST Thu Nov 24 2016
For aviation section.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 245 PM CST Thu Nov 24 2016
Very difficult cloud forecast for the next 12-24 hours. The NAM
and RAP models show much greater moisture 950-925mb through Friday
while the GFS/ECMWF show a decrease. Satellite trends show
clearing corresponds fairly well with a 15kt westerly 850mb flow
serving to work drying in from above into a shallow moist layer.
We are only a couple of hours from sunset. So, this clearing may
slow given the weak flow. Or, there could be some low cloud
redevelopment where it clears (fog?). Will have to monitor
closely. Updates can be expected to clouds. If the clouds hold,
most areas should remain slightly above guidance lows.
Overall there should be a decrease in clouds Friday through Friday
night. Dry weather on through Saturday with high pressure in
control through the duration. Went slightly below guidance for
Friday`s highs given lingering cloud potential. Again lower
confidence call here. Chilly Friday night and Saturday night.
Stayed near MOS for highs Saturday.
.LONG TERM...(Sunday through Thursday)
Issued at 245 PM CST Thu Nov 24 2016
Ridging aloft and retreating high pressure during the latter half of
the weekend over the Midwest will give way to increasing
southwesterlies through a deep layer Sunday night. This should
result in a "comma head" of light pcpn Sunday night to the southeast
of a deepening stacked low that will be headed for the Dakotas or MN.
For Monday afternoon and night, a lobe of energy in the expansive
mid level longwave over 2/3rds of the CONUS is progged by the med
range models to enhance lift and result in more robust rainfall
across most of the PAH forecast area. This should be when the most
QPF occurs. At this time, lightning potential is very low, and was
left out of the extended forecast for now. Total QPF is now
generally 1 to 2 inches, with higher amounts possible (subject to
change).
The weather picture gets a bit more murky after that, since the med
range models do begin to differ in the finer details, though they
are in somewhat better agreement in the large scale pattern details.
An additional difficult-to-time impulse or two in the parent
longwave may or may not follow, causing rain showers to possibly
linger well into Tuesday, and perhaps Tuesday night. At this time,
Wednesday and Thursday is forecast to be dry, though the 12Z ECMWF
run suggests another impulse in the southwesterly flow aloft could
trigger another batch of showers.
Sunshine may return for a while on Tuesday afternoon, resulting in
temps possibly reaching the middle 60s in southwestern IN/western
KY. There should be a cool down in the latter half of the week as
mid level heights fall and deep layer winds turn more
northwesterly.
&&
.AVIATION...
Issued at 542 PM CST Thu Nov 24 2016
Low MVFR 1-2 kft stratus will continue to hang around through the
night...possibly lifting into the higher MVFR categories by late
Friday morning. Most likely will not see clearing until later in
the TAF period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...GM
AVIATION...GM
Area Forecast Discussion
National Weather Service Pendleton OR
800 PM PST Thu Nov 24 2016
.UPDATE...Strongest wind gusts of 35 to 45 mph continue along the
northern Blue Mountain foothills this evening with lesser gusts
through the Grande Ronde Valley and east of the Wallowa. The winds
should be peaking around 06Z. HRRR models continues to indicate the
potential for gusts near 50 mph moving off the east slopes of the
Oregon Cascades through 10z. Will continue with the warnings and
advisories through 4 am. Band of precipitation west of the Cascades
will continue to push east reaching into the region on Friday
morning with showery conditions through the day. Minor updates to
forecast. 93
&&
.PREV DISCUSSION... /issued 440 PM PST Thu Nov 24 2016/
SHORT TERM...Tonight through Sunday...Multiple wind warnings and
advisories are in effect until 4 am PST Friday. A low pressure
system will move up along the coast tonight and into British
Columbia. This will tighten the southerly surface pressure gradient
and lead to strong and gusty winds especially when coupled with a 50
kt low level jet. The strongest winds will be over central Oregon
and along the Blue Mountain Foothills as well as the Grande Ronde
and Wallowa Valleys. Winds should peak in the mid to late evening
then slowly decrease overnight. Precipitation should be light and
mostly confined to the Cascade East Slopes. Have recently cancelled
the Winter Weather Advisory for the WA East Slopes. Snow levels have
risen to 3000 feet and expect mostly rain through the evening. There
could be a little snow returning overnight down to around 2800 feet
but expect the snow amounts to be light.
On Friday and Friday night expect scattered showers and snow showers
with most of the activity over the mountains. QPF amounts will be
light. Southerly pressure gradients will tighten again between 09-
18z Saturday and there is some potential for wind highlights during
that time period especially near the base of the Blue Mountains and
Grande Ronde Valley. For now increased the winds to near advisory
level in these areas for further evaluation. With broad troughiness
over the region into Sunday there will be a chance of rain and snow
mainly in the mountains with snow levels 3000-3500 feet. 78
LONG TERM...Sunday night through Thursday night...A strong focused
vorticity maximum in the mid/upper levels with attendant dynamic
lift rides over a mid/upper ridge of high pressure offshore and
moves rapidly southeastward along a moisture plume and a frontal
boundary into the interior Pacific Northwest late Sunday night with
snow levels of 2500-3000 feet thus producing a chance of
precipitation Sunday evening in central and NE Oregon and then
Basin/valley rain likely overnight in SE Washington and NE Oregon
and snow overnight in the Blue Mountains through Monday morning.
Snow accumulations of 3-6 inches may occur with this system in the
Blue Mountains from 10 PM Sunday evening until 10 AM on Monday
morning. The disturbance exits the region Monday afternoon, yet
orographic lift due to NW winds aloft over the NE Oregon mountains
will produce numerous snow showers in the mountains of NE Oregon and
the Blue Mountains in SE Washington through Monday afternoon. Monday
night and Tuesday a mid/upper level ridge of high pressure builds
over the forecast area yielding sinking air aloft, which will yield
a drier atmosphere at lower and mid levels for dry conditions on
Tuesday. Tuesday night into Wednesday expect increasing clouds
associated with a strong negatively tilted mid/upper level trough
moving out of the Gulf of Alaska and into the Pacific Northwest.
Snow levels with the aforementioned trough Tuesday night/Wednesday
will remain around 2500-3000 feet so the mountains will receive some
modest snow accumulations on the order or 2-4 inches at pass levels
with higher amounts of 3-5 inches possible above 4500 feet.
Precipitation with this system will be winding down and ending in
the Lower Columbia Basin and the Kittitas and Yakima Valleys by
Wednesday afternoon, although snow showers due to orographic lift
are expected in the Blue Mountains, the Wallowa Mountains and the
Elkhorn Mountains Wednesday night through Thursday afternoon with a
low chance of snow showers possible at higher mountain elevations in
NE Oregon through Thursday night. Snow showers should end by
Thursday evening elsewhere in the interior Pacific Northwest. Polan
AVIATION...00Z TAFs...A Pacific storm system and a stalled cold
front in NW Oregon will transport abundant moisture and mid level
clouds across south central and SE Washington as well as central and
NE Oregon over the next 24 hours with cloud bases of 5000-8000 feet
AGL. TAFs for KDLS, KRDM, KBDN, KPDT and KALW will have periods of
rain over the forecast period. KPSC will probably be dry through
tonight into Friday morning, although a cold front moving through
the Columbia Basin by late morning/early afternoon may deliver some
light rain at KPSC so have VCSH for KPSC starting at 18Z. KYKM will
be rain shadowed by downsloping winds off the east slopes of the
Washington Cascades. VFR conditions expected at all TAF sites for
the next 24 hours. Surface winds are a concern. A low level jet
stream with winds of 40-50 knots around 5000 feet above MSL will
remain through the period over the Columbia Basin and the foothills
of the Blue Mountains. Aircraft ascending into the low level jet or
descending out of the jet may encounter sharp vertical wind shear
resulting in jarring free air turbulence. Surface winds at KDLS,
KPSC, KPDT and KALW will need to be monitored closely. Southerly
downslope winds off the east slopes of the Oregon Cascades will
bring sustained winds at KRDM and KBDN of 12-16 kts and gusts to 26
kts. Downslope winds along the north facing slopes of the Blue
Mountains could result in gusts of 25-40 kts at times at KALW and
KPDT.
There is also the potential at KRDM and KBDN for the development of
rotor action in the lee of the Cascades. This rotor action can cause
the wind over an airfield to become temporarily lighter and from a
direction opposite to the main surface winds. This change in winds
can result in increased low level mechanical turbulence. Timing of
such conditions is not easy, but they will be included in TEMPO
groups with amendments when noticed. Polan
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 40 53 38 49 / 10 30 20 40
ALW 43 54 41 49 / 20 40 20 40
PSC 44 53 41 50 / 20 20 20 30
YKM 37 50 35 47 / 30 10 40 30
HRI 41 54 37 49 / 20 30 30 40
ELN 34 46 32 44 / 40 10 60 40
RDM 35 48 33 45 / 10 30 30 50
LGD 39 47 37 48 / 10 40 20 30
GCD 38 46 36 47 / 10 50 30 30
DLS 41 51 40 49 / 20 30 30 50
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 4 AM PST Friday for ORZ049-050-507-508.
High Wind Warning until 4 AM PST Friday for ORZ509-511.
WA...Wind Advisory until 4 AM PST Friday for WAZ029.
&&
$$
93/99/99
Area Forecast Discussion
National Weather Service Raleigh NC
930 PM EST Thu Nov 24 2016
.SYNOPSIS...
Mild air will overspread the area through Friday, followed by a cold
front passage Friday night. High pressure will build over the region
through the weekend. This high will shift to our east and off the
coast on Monday, with warm air returning for Tuesday and Wednesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Thursday...
With the warm front to our north and cold front still well to our
west, we`ll remain in the warm sector overnight, beneath weak
surface high pressure in the east and a weak lee trough in the west.
Surface winds are already very light and are expected to remain so
through the night, and with mild dewpoints in the upper 40s to mid
50s that are expected to dip only slightly overnight, areas of fog
will continue to develop and expand, particularly over the northeast
quarter of the forecast area where temp/dewpoint spread is already
small or zero. This is supported by the latest several HRRR runs.
850 mb winds will back a bit overnight, enough to result in an
uptick in moist isentropic upglide around 295K, beneath the
subsidence inversion aloft (which will strengthen further with
steady warm and dry air advection around 700 mb). Expect a trend to
partly to mostly cloudy skies everywhere over the next several hours
as stratocu fills in. Have made minor temp changes in spots in
response to latest trends, but lows remain generally in the upper
40s north to low-mid 50s south. -GIH
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 312 PM Wednesday...
Another progressive shortwave trough will track quickly east, in
clipper-like fashion, through the Mid-Atlantic region Friday
night/early Saturday. Attendant surface cold front is progged to
push SE through the area between 00 to 06z Saturday. Low-level flow
preceding the front is generally westerly east of the mountains,
which will severely limit moisture advection with this system.
Additionally, with better DPVA staying north of area, forcing is
rather modest and will be confined to low-level convergence along
the front.
Under partly to mostly cloudy skies, highs Friday afternoon
ranging from mid to upper 60s north to lower/mid 70s south.
Dry cold air advection in the wake of the front is expected to lead
to NW to SE clearing Friday night. Lows ranging from lower 40s NW to
mid/upper 40s SE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 400 PM Thursday...
Sat-Tue: In the wake of an upper level trough Friday night, ridging
aloft will build eastward from the central CONUS to the Mid-
Atlantic/Carolinas by early next week. Expect dry conditions and
above normal temperatures during this time.
Tue Night-Thu: Guidance is in relative good agreement with regard to
showing an upper level trough and attendant cold front approaching
slowly from the west late Tue/Wed before progressing eastward
through the Carolinas Wed night. Expect above normal temperatures
and a good chance for widespread rain based on 12Z guidance, though
precip timing/amounts are still quite uncertain given that this
is Day 6-7 and the system has yet to even develop. -Vincent
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 650 PM Thursday...
24 Hour TAF Period: Medium high confidence that conditions will drop
below VFR during the TAF period at least at eastern sites as low
level moisture appears high enough to at least produce some MVFR fog
but KRWI will most likely see a period of half mile fog or even
lower visibilities. KRDU and KFAY look primed for at least MVFR fog
during the early morning hours as dewpoint depressions remain very
low here. Back across the Triad there is more work to be done as the
temperature dewpoint spread is still around 10 degrees, but that is
expected to decrease during the overnight hours.
Outside of the fog situation, some light rain will be possible on
Friday afternoon, particularly at the three eastern terminals, and
this could continue through the end of the TAF period. Winds
everywhere Friday will be light and mainly out of the southwest.
Long Term: Looking beyond the TAF period, the next chance for some
rain will be Tuesday for the Triad sites and then across the rest of
the area on Wednesday before clearing back out for the end of the
week.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Hartfield
NEAR TERM...Hartfield
SHORT TERM...CBL
LONG TERM...Vincent
AVIATION...Ellis
Area Forecast Discussion
National Weather Service Columbia SC
453 AM EST Fri Nov 25 2016
.SYNOPSIS...
A weak frontal boundary in the forecast area will push east of the
area tonight as high pressure shifts eastward. Little moisture is
associated with the front. The ridging will dominate Saturday and
Sunday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Patchy fog should dissipate early this morning because of heating
and mixing. The models display the front in the forecast area
shifting east of the area this evening. A little convergence
associated with the front plus a mid-level shortwave trough could
help support showers but expect little coverage. The models and
observation trends indicate little moisture. The HRRR displayed
isolated shower coverage and an average of the NAM and GFS MOS
supported slight chance pops. Coverage may be greatest in the
southeast section closer to somewhat deeper moisture. It will be
warm ahead of the front today. Leaned toward the higher
temperature guidance. Followed the guidance consensus temperature
tonight.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
The models display surface ridging in the forecast area Saturday
and Sunday. The h5 trough is forecast to shift off the coast early
Saturday with the following ridge moving over the region Sunday.
The pattern supports dry conditions. Followed the guidance
consensus for the temperature forecast.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The GFS and ECMWF indicate a moisture increase Monday and Tuesday
in the return southerly flow associated with offshore high
pressure and an approaching front. The models show the deepest
moisture Wednesday and Wednesday night with drying behind the
front Thursday. Previous runs of the ECMWF have been slower with
moisture lingering Thursday. The models have generally indicated
the highest pops Wednesday with values 50 to 60 percent. The GFS
and ECMWF have been consistent depicted a strong h85 jet which may
help support enough instability for a few thunderstorms. The MOS
indicates temperatures near normal Sunday night and above normal
during the rest of the medium-range period.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
Surface high pressure will remain centered off the coast through
Friday. A weak dry front will move into the area and linger
through the period. VFR conditions will dominate at the terminals,
but shallow moisture and nocturnal cooling may lead to
restrictions in fog early this morning. The latest CAE VWP
indicating SW winds around 20 kts at 2 kft early this morning.
Latest LAMP guidance less pessimistic about restrictive fog than
previous runs. Think MVFR fog possible at AGS and OGB, but mainly
VFR elsewhere before 14Z. After 14Z, VFR will prevail across the
area. Models indicate possible light showers later this
afternoon, but confidence is too low to mention at any of the TAF
sites at this time.
EXTENDED AVIATION OUTLOOK...No significant restrictions to
aviation expected at this time.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
419 AM EST Fri Nov 25 2016
.SYNOPSIS...
A weak cold front will move slowly east of the area today with dry
high pressure returning over the weekend. Deep layer moisture will
increase from the west early next week ahead of an approaching cold
front with much needed rainfall expected Tuesday and Wednesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 400 AM EST: A diffuse surface cold front continues a slow
march east across the foothills and piedmont this morning. With no
surface based instability apparent and little to no forcing
accompanying the front, no PoPs will be featured for eastern
sections this morning. This is in agreement with the latest HRRR
runs that keep any isolated to scattered shower activity from
forming until the boundary moves east of our piedmont by midday. We
continue to monitor the mountain valleys and foothills for
visibility problems associated with fog formation in the moist
boundary layer, topped by mid and dry air aloft, with smoke
particles nearby. An SPS addressing this concern has been posted
through 15Z.
Heights will fall from the west today as a shallow trough amplifies
from the upper Midwest to the TN valley. This should give the
surface front the kick it needs to finally move off to the east of
the area. With mainly scattered clouds, heating should be sufficient
for plenty of 70s temperatures but generally a touch below record
highs for the date. A weak shortwave will cross the region tonight
with improving NW flow and moderate cold advection kicking in.
Minimum temperatures will return to near, or just above, climo
overnight.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 200 AM Friday...the short term looks to be the quietest period
of the next seven days. Upper heights will begin to rise during the
day on Saturday while a surface high slides into the southeastern
CONUS, suppressing rain chances (and most cloud cover for that
matter) and keeping winds generally light. Sunday will remain dry
and relatively calm with the surface high becoming centered over the
Carolinas during the day, though the progressive pattern will allow
the high to move off the coast of the Carolinas by Sunday night as
an upper ridge axis shifts over the southern Appalachians. It still
appears that although RHs could briefly drop to the low 30s Saturday
and Sunday afternoons, good overnight recovery will occur both
nights. Both maximum and minimum temperatures will be about a
category above average on Saturday and closer to normal on Sunday.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 245 AM Fri: Models continue to depict a deep trough developing
over the western US early next week, and a Plains surface low
spinning up in response, which will bring a cold front across the
Southeast in some fashion in the middle of the week. The moist
southerly flow ahead of the front may initiate precip over the Blue
Ridge as soon as Monday afternoon. Precip is likely to expand to
the bulk of the CWFA on Tuesday. Temps will warm several degrees
above normal by Tue, warmer still on Wed.
Models continue to differ in how they depict the interaction of the
front with an embedded shortwave swinging thru the Southern Plains
Wednesday. Latest EC solution pushes the cold front out of our
area Tue night, but develops a frontal wave across the Deep South
in response to the shortwave. This brings another intense round
of rainfall Wed into early Thu as this passes thru our area. The
GFS is slower to advect the front eastward, more or less pivoting
it over the CWFA, and showing less distinction between the two
rounds. Nonetheless it is looking likely that between Mon night
and Thu, we`ll get the soaking rainfall we`ve been wishing for. I
opted not to go as high with QPF as WPC, mainly because a minor
shift in where the front stalls/pivots could lead to remarkably
different rainfall.
The timing of the front currently looks a bit more supportive
of severe weather than once shown. Wednesday both the GFS and EC
develop CAPE over portions of the area concurrent with 40-50 kt
flow at 850mb. The EC depiction of the Piedmont being brought into
the warm sector for a time on Wed is particularly interesting. For
now I have introduced slight chance thunder over most zones,
but I will not make any HWO comments at this time. It still looks
like any air cold enough for a wintry changeover will not arrive
until the end of the event. No snow is being mentioned with this
package. Temps drop back to near climo Thu.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
At KCLT and the Upstate TAF Sites: Expect mainly a scattered to
broken VFR stratocumulus field this morning and through much of the
day as a weak cold front gradually moves east. The boundary layer
remains moist enough that MVFR fog will be possible around daybreak
and some lower stratus could form. The main threat will be around
KAND through 13Z. Light SW flow will turn NW this evening.
At KAVL and KHKY: The potential for lowering visibility from smoke
and fog and is much higher in the mountain valleys and across the NC
foothills. Model profiles, however, are sending mixed signals on
whether the VFR stratocumulus or near surface stratus will be the
main cloud feature through daybreak, but a period of MVFR TEMPO IFR
low clouds and fog/smoke seems reasonable after 09Z. Otherwise,
expect mainly SCT VFR clouds through the day with generally light SW
surface winds. Flow will turn NW late today and possibly increase
into the evening with the onset of better cold advection.
Outlook: Drier high pressure returns for the weekend. The main
threat of restrictions through the period should be associated with
smoke plumes. More abundant rainfall, and associated restrictions,
looks increasingly likely next Tuesday/Wednesday.
Confidence Table...
09-15Z 15-21Z 21-03Z 03-06Z
KCLT High 94% High 100% High 100% High 100%
KGSP High 94% High 100% High 100% High 100%
KAVL Low 44% High 100% High 100% Med 65%
KHKY High 94% High 100% High 100% High 100%
KGMU High 94% High 100% High 100% High 100%
KAND High 89% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.FIRE WEATHER...
Low temps should manage to reach or exceed crossover temperatures
across most of the region this morning. Based on the values of
RH, LVORI, ADI, and light winds, it appears that conditions will
favor superfog toward daybreak, especially near wildfires. This
is highlighted in an SPS for areas of dense fog/smoke.
A dry airmass will begin to spread across the region through the
day, remaining through the weekend and into early next week. A
powerful mid level wave will approach the region at that time. At
the surface, a cold front is expected to sweep in from the west,
with prefrontal winds increasing from the SE. This pattern should
bring deep moisture from the Gulf of Mexico. The combination of deep
moisture, upslope flow, and a large area of synoptic scale forcing
indicates precipitation may start as early as Monday afternoon
over the mountains, with widespread rain across the forecast area
late Tuesday into Wednesday. Guidance indicates that the potential
exists for 1-4 inches of rain across the mtns and foothills.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...HG
NEAR TERM...HG
SHORT TERM...LEV
LONG TERM...Wimberley
AVIATION...HG
FIRE WEATHER...HG/Wimberley
Area Forecast Discussion
National Weather Service Lincoln IL
310 AM CST Fri Nov 25 2016
.SHORT TERM...(Today and tonight)
ISSUED AT 310 AM CST Fri Nov 25 2016
Low clouds continue to blanket much of the Midwest early this
morning, and it appears any clearing across central Illinois will be
a slow-go today. 09z/3am IR satellite imagery shows overcast
conditions extending as far west as eastern Nebraska/Kansas. While
there had been a few breaks in the overcast across eastern Missouri
earlier, those have since filled back in. Latest HRRR forecast
shows cloud cover holding firm until late this afternoon across the
far SW KILX CWA. Have therefore slowed the clearing trend and have
gone with a cloudy forecast today. In addition, a short-wave trough
skirting by to the north may bring a few sprinkles to locations
north of Peoria. Once the wave passes to the east, skies will
finally clear from west to east tonight. Due to extensive cloud
cover, high temperatures today will be held in the middle 40s. Low
temperatures tonight will dip into the lower 30s.
&&
.LONG TERM...(Saturday through Thursday)
ISSUED AT 310 AM CST Fri Nov 25 2016
Upper-level ridging will build into the Midwest for Saturday and
Sunday, providing warm and dry conditions. High temperatures will
climb into the 50s both days.
The next chance for precipitation will hold off until Sunday night
when a short-wave trough approaches from the west. 00z Nov 25
models are all in good agreement with the track and timing of this
feature, with rain showers becoming numerous across the area Sunday
night. Once the initial wave lifts into the Upper Midwest/Great
Lakes, a lull in the precip will be observed Monday morning before
another more significant wave approaches later in the day. With
deep-layer southwesterly flow in place from the Southern Plains to
the Ohio River Valley, copious amounts of moisture will flow
northward ahead of the next disturbance...with GFS precipitable
water values reaching near record values for this time of year
around 1.25. The wave will interact with this ample moisture to
produce heavy rainfall across parts of central/southeast Illinois.
As has been seen with recent model runs, the latest run is
suggesting the heaviest rain axis will set up across the SE CWA
from Monday afternoon through Monday night. All models are now
advertising a quicker exit to the system, with the rain
diminishing to scattered showers by Tuesday morning. The latest
projections show rainfall totals of 1 to 1.50 along/south of I-70.
Once the early week storm passes, a return to mild and dry weather
is anticipated for the remainder of the extended. The 00z GFS/ECMWF
both feature dry conditions for Wednesday and Thursday, with another
wave lifting northeastward across the Tennessee/Ohio River Valleys.
This scenario would keep rain chances southeast of Illinois across
Kentucky/southern Indiana. Meanwhile, the GEM features a much
stronger wave tracking further to the northwest, resulting in rain
across central Illinois on Wednesday. Given the poor performance of
the GEM as of late and the fact that its the definite outlier, have
rejected its solution in favor of the dry GFS/ECMWF consensus.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1140 PM CST Thu Nov 24 2016
Expect an MVFR stratocumulus deck to continue to dominate a
majority of this TAF forecast period. Satellite images are showing
widespread clouds over the Midwest, with a blanket of clouds all
the way west to eastern Nebraska and eastern Kansas. However,
satellite images also show a small opening the overcast
approaching SPI from the W-SW. It is possible that brief VFR
conditions develop at SPI, but clouds should fill back in again
before sunrise. Cloud re-development should be aided by a
pronounced inversion that will be reinforced as the ground level
airmass cools overnight.
Forecast soundings are pointing toward little clearing all the way
through tomorrow morning. Cloud ceiling heights should climb
toward VFR toward 18z, with some clearing of the clouds from SW to
NE as the afternoon progresses. Therefore, keeping MVFR conditions
tonight and at least through around midday on Friday. VFR clouds
seem possible by mid afternoon, with clearing Friday evening from
west to east under advancing high pressure.
Winds will remain W-NW through the entire TAF period, with speeds
prevailing below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
Area Forecast Discussion
National Weather Service Pendleton OR
930 PM PST Thu Nov 24 2016
.UPDATE...Strongest wind gusts of 35 to 45 mph continue along the
northern Blue Mountain foothills this evening with lesser gusts
through the Grande Ronde Valley and east of the Wallowa. The winds
should be peaking around 06Z. HRRR models continues to indicate the
potential for gusts near 50 mph moving off the east slopes of the
Oregon Cascades through 10z. Will continue with the warnings and
advisories through 4 am. Band of precipitation west of the Cascades
will continue to push east reaching into the region on Friday
morning with showery conditions through the day. Minor updates to
forecast. 93
AVIATION...06Z TAFs...Winds 15-25 Kts with gusts to 30 Kts will
continue at KPDT, KALW KPSC through 12z. Other locations should see
wind 10-15 kts overnight. A frontal band with rain showers will push
east into the region by Friday morning with some light rain showers
possible at most locations after 15z with ceilings 5000-7000 feet
through most of the period. Winds will be 10-15 kts with gusts to
20kts.
&&
.PREV DISCUSSION... /issued 440 PM PST Thu Nov 24 2016/
SHORT TERM...Tonight through Sunday...Multiple wind warnings and
advisories are in effect until 4 am PST Friday. A low pressure
system will move up along the coast tonight and into British
Columbia. This will tighten the southerly surface pressure gradient
and lead to strong and gusty winds especially when coupled with a 50
kt low level jet. The strongest winds will be over central Oregon
and along the Blue Mountain Foothills as well as the Grande Ronde
and Wallowa Valleys. Winds should peak in the mid to late evening
then slowly decrease overnight. Precipitation should be light and
mostly confined to the Cascade East Slopes. Have recently cancelled
the Winter Weather Advisory for the WA East Slopes. Snow levels have
risen to 3000 feet and expect mostly rain through the evening. There
could be a little snow returning overnight down to around 2800 feet
but expect the snow amounts to be light.
On Friday and Friday night expect scattered showers and snow showers
with most of the activity over the mountains. QPF amounts will be
light. Southerly pressure gradients will tighten again between 09-
18z Saturday and there is some potential for wind highlights during
that time period especially near the base of the Blue Mountains and
Grande Ronde Valley. For now increased the winds to near advisory
level in these areas for further evaluation. With broad troughiness
over the region into Sunday there will be a chance of rain and snow
mainly in the mountains with snow levels 3000-3500 feet. 78
LONG TERM...Sunday night through Thursday night...A strong focused
vorticity maximum in the mid/upper levels with attendant dynamic
lift rides over a mid/upper ridge of high pressure offshore and
moves rapidly southeastward along a moisture plume and a frontal
boundary into the interior Pacific Northwest late Sunday night with
snow levels of 2500-3000 feet thus producing a chance of
precipitation Sunday evening in central and NE Oregon and then
Basin/valley rain likely overnight in SE Washington and NE Oregon
and snow overnight in the Blue Mountains through Monday morning.
Snow accumulations of 3-6 inches may occur with this system in the
Blue Mountains from 10 PM Sunday evening until 10 AM on Monday
morning. The disturbance exits the region Monday afternoon, yet
orographic lift due to NW winds aloft over the NE Oregon mountains
will produce numerous snow showers in the mountains of NE Oregon and
the Blue Mountains in SE Washington through Monday afternoon. Monday
night and Tuesday a mid/upper level ridge of high pressure builds
over the forecast area yielding sinking air aloft, which will yield
a drier atmosphere at lower and mid levels for dry conditions on
Tuesday. Tuesday night into Wednesday expect increasing clouds
associated with a strong negatively tilted mid/upper level trough
moving out of the Gulf of Alaska and into the Pacific Northwest.
Snow levels with the aforementioned trough Tuesday night/Wednesday
will remain around 2500-3000 feet so the mountains will receive some
modest snow accumulations on the order or 2-4 inches at pass levels
with higher amounts of 3-5 inches possible above 4500 feet.
Precipitation with this system will be winding down and ending in
the Lower Columbia Basin and the Kittitas and Yakima Valleys by
Wednesday afternoon, although snow showers due to orographic lift
are expected in the Blue Mountains, the Wallowa Mountains and the
Elkhorn Mountains Wednesday night through Thursday afternoon with a
low chance of snow showers possible at higher mountain elevations in
NE Oregon through Thursday night. Snow showers should end by
Thursday evening elsewhere in the interior Pacific Northwest. Polan
.PRELIMINARY POINT TEMPS/POPS...
PDT 40 53 38 49 / 10 30 20 40
ALW 43 54 41 49 / 20 40 20 40
PSC 44 53 41 50 / 20 20 20 30
YKM 37 50 35 47 / 30 10 40 30
HRI 41 54 37 49 / 20 30 30 40
ELN 34 46 32 44 / 40 10 60 40
RDM 35 48 33 45 / 10 30 30 50
LGD 39 47 37 48 / 10 40 20 30
GCD 38 46 36 47 / 10 50 30 30
DLS 41 51 40 49 / 20 30 30 50
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 4 AM PST Friday for ORZ049-050-507-508.
High Wind Warning until 4 AM PST Friday for ORZ509-511.
WA...Wind Advisory until 4 AM PST Friday for WAZ029.
&&
$$
93/99/93
Area Forecast Discussion
National Weather Service Raleigh NC
328 AM EST Fri Nov 25 2016
.SYNOPSIS...
A cold front will push through the area tonight. High pressure will
follow the front, bringing dry and cooler air for the weekend into
early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 150 AM FRIDAY...
A weak surface trough was located over the western Piedmont this
morning, as the cold front stalled over the western slopes of the
Appalachians. Additional mid/upper level energy will finally arrive
late today and tonight which will give the front a definitive push
across the mountains and through our region this evening. There is
essentially nothing to produce lift for much of today. Therefore,
expect partly sunny skies and temperatures expected to reach the mid
60s along the NC/border, near 70 in the interior, and lower 70s
south.
A few models led by the HRRR depict the development of a few showers
along the front this evening, mainly over the eastern Piedmont
tracking east to the coast before midnight. This again is not
expected to be a significant event with a QFP of only a few
hundredths to a tenth of an inch on average. CAA and DAA will arrive
overnight with a wind shift to the north. Mostly cloudy skies will
clear overnight in the west and north. Lows generally in the 40s NW
to 50s SE.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 150 AM FRIDAY...
Clearing will gradually surge on to the south and east through the
Coastal Plain through the morning Saturday. Otherwise, high pressure
of Pacific origin will continue to build into the region from the
Midwest.
Expect mostly sunny skies Saturday afternoon with highs in the 55-60
range NW and 60-65 SE. Lows with clear skies Saturday night will be
very near normal, in the 33-38 range for the most part.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 325 AM Friday...
Sunday through Monday: Surface high pressure over the area on Sunday
will shift offshore on Monday, while a mid level ridge will build
across the area. This will yield a warming trend, with increasing
mid/high clouds by Monday. Dry weather is expected though, with
highs in the mid to upper 50s on Sunday and highs in the lower to
mid 60s on Monday. Low temps Monday morning are expected to be in
the lower to mid 30s.
Monday night through Thursday: Medium range guidance continues to
show the mid/upper level flow pattern amplifying next week, as a
full latitude trough is expected to develop. This will yield deep
southwesterly flow aloft to develop and transport increasing
moisture. A cold front is expected to approach/move into the area,
but slow as the front becomes parallel to the mid level flow. This
will yield increasing chances for showers and possibly some storms
by Tuesday into Wednesday, with above normal temps expected. Will
keep pops in the chance category for now, as enough differences
still exist with regard to the evolution of the deep trough and
expected additional s/w impulses lifting quickly northeastward from
the base of the trough (which will help push the front through the
area finally by Wednesday or Thursday). It appears this system
should bring widespread beneficial rains to the area next week (so
high pops will be needed once timing becomes more certain).
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
As of 1240 AM Friday...
24 Hour TAF Period: VFR conditions are generally expected. However,
patchy MVFR VSBYS will occur between 09Z-14Z, KRWI will be LIFR
through 13z then becoming VFR between 13z-15z.
A cold front will push into the region from the north this evening.
A wind shift to the north will occur with SW winds becoming N at
10kt between 23z/today and 03z/Sat. A brief light shower may occur
with the front over areas east of KRDU.
Long Term: Looking beyond the TAF period, VFR conditions are
expected this weekend into early next week.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Badgett
NEAR TERM...Badgett
SHORT TERM...Badgett
LONG TERM...BSD
AVIATION...Badgett
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
908 AM CST Fri Nov 25 2016
.UPDATE...
Quick update this morning to accommodate for the current radar
and temperature trends. Current observations are running a degree
or two above the forecast so have trended temps towards current
observations and adjusted highs by about a degree or two in spots.
The main change for this update is to increase chances for
precipitation (mainly showers) across Northern Val Verde County,
the Hill Country, and areas north of the Austin Metro Area. The
radar currently shows light to moderate rain from Lampasas to
Belton to Rockdale north of the area. The HRRR and Texas Tech WRF
both show some of this activity sinking south through the late
morning hours into the afternoon. Rainfall amounts will generally
average a few hundredths of an inch up to a tenth of an inch for
the day. Areas not seeing precipitation should stay mostly cloudy
throughout the day as well.
&&
.PREV DISCUSSION... /ISSUED 544 AM CST Fri Nov 25 2016/
AVIATION...
Overrunning situation will be in place across South Central Texas
the next 24+ hours as light north surface winds work across the
area. This combined with southerly winds just a few thousand feet
up will keep a fairly thick layer of clouds across the taf sites
through the day into tomorrow morning. Have some patchy dense fog
across SAT/SSF this morning and that should improve slightly by
late morning although may be in IFR for much of the day. Some
shower activity is already showing up near AUS and points north
and northwest. Kept mention of VCSH across the I35 Corridor much
of the day. Not looking for much improvement late today into early
Saturday morning with the good isentropic lift continuing. NAM/GFS
are differing a bit on how low the decks will be overnight
tonight...went on the lower end of ceilings closer to the MAV MOS
guidance.
PREV DISCUSSION... /ISSUED 341 AM CST Fri Nov 25 2016/
SHORT TERM (Today through Saturday)...
Patchy fog has developed and will mention through just after
daybreak. A weak cold front will drift to the south across South
Central Texas today. Just above the shallow front, flow remains
southerly with a westerly flow of the upper level jet aloft.
Isentropic lift slowly develops over our area leading to isolated
to scattered showers. So far, the TTU-WRF has best representation
of ongoing showers over West Central into Central Texas. Expect
these to drift to the south into the Hill Country to along the
Escarpment areas this morning. Other showers are noted off the
Texas coast. These will drift to the northwest to areas near the
Coastal Plains. One or two thunderstorms may develop during peak
heating during this afternoon. The isentropic lift slowly wanes
late this afternoon and shifts west to the Rio Grande Plains and
Edwards Plateau this evening into the overnight with showers
confined to those areas. Upper level ridging briefly builds into
Texas on Saturday leading to a more stable pattern. However,
cannot rule out an isolated shower or two along the Rio Grande due
possible weak isentropic lift remaining there.
LONG TERM (Saturday Night through Thursday)...
By Sunday, an upper level trough is located over the western
states. A lead shortwave moves to the northeast across the Plains.
An enhanced low level jet may yield some showers over the Hill
Country to the Rio Grande Plains Sunday morning. On Monday, a
stronger shortwave and surface cold front move across the Plains
and Texas. The ECMWF and GEM remain the fastest bringing these
features through early in the day while the GFS is slower with
passage later in the day into the evening. For now, will continue
to favor the slower timing of the GFS. These features will bring
slight to low chances of showers and thunderstorms. With a slower
timing, there is a possibility of moderate CAPE, which could allow
for isolated strong thunderstorms along and east of highway 281
in the afternoon into early evening. The main trough moves across
the Plains and Texas late Tuesday into early Wednesday. However,
most moisture will have been scoured out by the Monday system and
showers and storms are not expected. Just beyond this forecast,
there is a potential for a wet pattern next weekend as another
upper level trough and cold front move across our area.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 67 50 67 54 73 / 60 10 - 0 10
Austin Bergstrom Intl Airport 67 49 67 53 74 / 50 10 - 0 10
New Braunfels Muni Airport 69 51 68 55 75 / 50 10 - 0 10
Burnet Muni Airport 62 47 64 53 69 / 70 10 - 0 20
Del Rio Intl Airport 69 55 65 59 72 / 40 40 10 10 20
Georgetown Muni Airport 63 47 65 53 71 / 70 10 - 0 20
Hondo Muni Airport 72 52 70 56 76 / 40 10 - 10 10
San Marcos Muni Airport 69 50 69 54 74 / 50 10 - 0 10
La Grange - Fayette Regional 71 51 69 54 75 / 50 10 - 0 -
San Antonio Intl Airport 70 52 69 56 74 / 50 10 - - 10
Stinson Muni Airport 71 53 69 57 76 / 50 10 - - 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...Oaks
Synoptic/Grids...Treadway
Public Service/Data Collection...Williams
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1020 AM EST Fri Nov 25 2016
.SYNOPSIS...
A weak cold front will move slowly east of the area today with dry
high pressure returning over the weekend. Deep layer moisture will
increase from the west early next week ahead of an approaching cold
front with much needed rainfall expected Tuesday and Wednesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1015 AM EST Friday: Allowed for on time expiration of the Dense Fog
Advisory across the southwest/central NC mtns as visibilities
continue to improve. However, did reissue the SPS product for
another hour to highlight lingering issues, especially in the Little
TN River valley where visibilities remain low due to fog/smoke.
Skies continue to sct through morning as the atm heats, with only a
few lingering low stratus across the Lakelands region as well as
over the mtns. Temperatures are on the rise, however with trends
slightly behind the previous fcst, therefore opted to tweak hourly
t/td slightly to fit recent trends. No other sig changes were
needed/made.
Otherwise, a diffuse surface cold front continues a slow march east
across the foothills and piedmont this morning. With no surface
based instability apparent and little to no forcing accompanying the
front, no PoPs will be featured for eastern sections this morning.
This is in agreement with the latest HRRR runs that keep any
isolated to scattered shower activity from forming until the
boundary moves east of our piedmont by midday.
Heights will fall from the west today as a shallow trough amplifies
from the upper Midwest to the TN valley. This should give the
surface front the kick it needs to finally move off to the east of
the area. With mainly scattered clouds, heating should be sufficient
for plenty of 70s temperatures but generally a touch below record
highs for the date. A weak shortwave will cross the region tonight
with improving NW flow and moderate cold advection kicking in.
Minimum temperatures will return to near, or just above, climo
overnight.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 200 AM Friday...the short term looks to be the quietest period
of the next seven days. Upper heights will begin to rise during the
day on Saturday while a surface high slides into the southeastern
CONUS, suppressing rain chances (and most cloud cover for that
matter) and keeping winds generally light. Sunday will remain dry
and relatively calm with the surface high becoming centered over the
Carolinas during the day, though the progressive pattern will allow
the high to move off the coast of the Carolinas by Sunday night as
an upper ridge axis shifts over the southern Appalachians. It still
appears that although RHs could briefly drop to the low 30s Saturday
and Sunday afternoons, good overnight recovery will occur both
nights. Both maximum and minimum temperatures will be about a
category above average on Saturday and closer to normal on Sunday.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 245 AM Fri: Models continue to depict a deep trough developing
over the western US early next week, and a Plains surface low
spinning up in response, which will bring a cold front across the
Southeast in some fashion in the middle of the week. The moist
southerly flow ahead of the front may initiate precip over the Blue
Ridge as soon as Monday afternoon. Precip is likely to expand to
the bulk of the CWFA on Tuesday. Temps will warm several degrees
above normal by Tue, warmer still on Wed.
Models continue to differ in how they depict the interaction of the
front with an embedded shortwave swinging thru the Southern Plains
Wednesday. Latest EC solution pushes the cold front out of our
area Tue night, but develops a frontal wave across the Deep South
in response to the shortwave. This brings another intense round
of rainfall Wed into early Thu as this passes thru our area. The
GFS is slower to advect the front eastward, more or less pivoting
it over the CWFA, and showing less distinction between the two
rounds. Nonetheless it is looking likely that between Mon night
and Thu, we`ll get the soaking rainfall we`ve been wishing for. I
opted not to go as high with QPF as WPC, mainly because a minor
shift in where the front stalls/pivots could lead to remarkably
different rainfall.
The timing of the front currently looks a bit more supportive
of severe weather than once shown. Wednesday both the GFS and EC
develop CAPE over portions of the area concurrent with 40-50 kt
flow at 850mb. The EC depiction of the Piedmont being brought into
the warm sector for a time on Wed is particularly interesting. For
now I have introduced slight chance thunder over most zones,
but I will not make any HWO comments at this time. It still looks
like any air cold enough for a wintry changeover will not arrive
until the end of the event. No snow is being mentioned with this
package. Temps drop back to near climo Thu.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
At KCLT: Lingering stratocumulus has largely kept any daybreak fog
issues at bay. We could see still 5 to 6 sm in light fog for a
couple of hours but confidence is too low to carry any restrictions
in the TAF. Otherwise, the clouds will further scatter today as the
passing weak cold front gradually moves east. Light SW surface winds
will turn NW this evening then northeast overnight.
Elsewhere: Dense fog around daybreak is confined mainly to the
southwest NC mountain valleys as well as KAVL and KAND. There
remains the potential for brief dense fog/smoke to form at KHKY, but
lingering stratocumulus has limited the potential thus far.
Otherwise, expect mainly FEW to SCT VFR clouds through the day with
generally light SW surface winds. Flow will turn NW late today and
possibly increase into the evening with the onset of better cold
advection tonight. KAND could see another round of fog overnight if
the winds decouple sufficently.
Outlook: Drier high pressure returns for the weekend. The main
threat of restrictions through the period should be associated with
smoke plumes. More abundant rainfall, and associated restrictions,
looks increasingly likely next Tuesday/Wednesday.
Confidence Table...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 84% High 100% Low 56% Low 57%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% Med 77%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.FIRE WEATHER...
Low temps should manage to reach or exceed crossover temperatures
across most of the region this morning. Based on the values of
RH, LVORI, ADI, and light winds, it appears that conditions will
favor superfog toward daybreak, especially near wildfires. This
is highlighted in an SPS for areas of dense fog/smoke.
A dry airmass will begin to spread across the region through the
day, remaining through the weekend and into early next week. A
powerful mid level wave will approach the region at that time. At
the surface, a cold front is expected to sweep in from the west,
with prefrontal winds increasing from the SE. This pattern should
bring deep moisture from the Gulf of Mexico. The combination of deep
moisture, upslope flow, and a large area of synoptic scale forcing
indicates precipitation may start as early as Monday afternoon
over the mountains, with widespread rain across the forecast area
late Tuesday into Wednesday. Guidance indicates that the potential
exists for 1-4 inches of rain across the mtns and foothills.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...HG
NEAR TERM...CDG/HG
SHORT TERM...LEV
LONG TERM...Wimberley
AVIATION...HG
FIRE WEATHER...HG/Wimberley
Area Forecast Discussion
National Weather Service Lincoln IL
946 AM CST Fri Nov 25 2016
.UPDATE...
Issued at 945 AM CST Fri Nov 25 2016
Main concern remains with the extensive cloud cover and how it
will affect temperatures today. Morning sounding continues to show
a subsidence inversion around 870 mb, with cloud thicknesses
around 1800-2000 feet per area pilot reports. Some small breaks
have formed across northeast Illinois and a bit of sunshine is
likely around Champaign and Danville through midday, but there
still is a lot of cloud cover upstream through central Iowa.
Forecast soundings show the cloud thicknesses shrinking with time,
and some more sunshine should start to appear over the southwest
CWA by mid afternoon. Temperatures are running a few degrees below
the original forecast curve, and have been updated to lower highs
a degree or two.
Radar mosaics showing rain and snow showers across Wisconsin and
parts of northeast Illinois ahead of a shortwave pushing through
the Minneapolis area. Some earlier sprinkles passed just north of
our CWA, with the HRRR suggesting the activity currently over
west central Wisconsin may make a close pass as well later this
afternoon. Have added a few sprinkles to the far northeast fringes
of the CWA this afternoon, but am not expecting anything
significant at this time.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 310 AM CST Fri Nov 25 2016
Low clouds continue to blanket much of the Midwest early this
morning, and it appears any clearing across central Illinois will be
a slow-go today. 09z/3am IR satellite imagery shows overcast
conditions extending as far west as eastern Nebraska/Kansas. While
there had been a few breaks in the overcast across eastern Missouri
earlier, those have since filled back in. Latest HRRR forecast
shows cloud cover holding firm until late this afternoon across the
far SW KILX CWA. Have therefore slowed the clearing trend and have
gone with a cloudy forecast today. In addition, a short-wave trough
skirting by to the north may bring a few sprinkles to locations
north of Peoria. Once the wave passes to the east, skies will
finally clear from west to east tonight. Due to extensive cloud
cover, high temperatures today will be held in the middle 40s. Low
temperatures tonight will dip into the lower 30s.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 310 AM CST Fri Nov 25 2016
Upper-level ridging will build into the Midwest for Saturday and
Sunday, providing warm and dry conditions. High temperatures will
climb into the 50s both days.
The next chance for precipitation will hold off until Sunday night
when a short-wave trough approaches from the west. 00z Nov 25
models are all in good agreement with the track and timing of this
feature, with rain showers becoming numerous across the area Sunday
night. Once the initial wave lifts into the Upper Midwest/Great
Lakes, a lull in the precip will be observed Monday morning before
another more significant wave approaches later in the day. With
deep-layer southwesterly flow in place from the Southern Plains to
the Ohio River Valley, copious amounts of moisture will flow
northward ahead of the next disturbance...with GFS precipitable
water values reaching near record values for this time of year
around 1.25. The wave will interact with this ample moisture to
produce heavy rainfall across parts of central/southeast Illinois.
As has been seen with recent model runs, the latest run is
suggesting the heaviest rain axis will set up across the SE CWA
from Monday afternoon through Monday night. All models are now
advertising a quicker exit to the system, with the rain
diminishing to scattered showers by Tuesday morning. The latest
projections show rainfall totals of 1 to 1.50 along/south of I-70.
Once the early week storm passes, a return to mild and dry weather
is anticipated for the remainder of the extended. The 00z GFS/ECMWF
both feature dry conditions for Wednesday and Thursday, with another
wave lifting northeastward across the Tennessee/Ohio River Valleys.
This scenario would keep rain chances southeast of Illinois across
Kentucky/southern Indiana. Meanwhile, the GEM features a much
stronger wave tracking further to the northwest, resulting in rain
across central Illinois on Wednesday. Given the poor performance of
the GEM as of late and the fact that its the definite outlier, have
rejected its solution in favor of the dry GFS/ECMWF consensus.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 559 AM CST Fri Nov 25 2016
High pressure will track across the central Illinois terminal area
through the 12Z TAF valid time. The MVFR CIGs trapped across the
area today will gradually lift to VFR by this evening. The skies
will eventually scatter out tonight. Generally light winds will
prevail through the period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
Area Forecast Discussion
National Weather Service Blacksburg VA
1102 AM EST Fri Nov 25 2016
.SYNOPSIS...
A weak low pressure over the Southern Appalachains this morning
tracks east to the coastal plains of North Carolina this evening. This
low will then move off the coast tonight as high pressure moves
from the southern plains to the Tennessee Valley on Saturday. The
high will be overhead Sunday. A large low pressure system will
move from Rockies to the northeast United States Sunday through
Thursday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1054 AM EST Friday...
Fog will stick around for another few hours in the higher terrain
of WV into far SW VA then clear up early this afternoon.
Do not see much threat of showers this afternoon with weak forcing
and flow. Although with the low moving across the northern portion
of North Carolina cannot rule out an isolated shower or sprinkle.
Overall kept the isolated shower threat over the western slopes of
Southeast West Virginia. Cut back on sky cover early as more
sunshine realized east of the mountains, but will still see clouds
increasing over the course of the afternoon. Still mild with highs
ranging from the upper 60s in the Piedmont to upper 40s to lower
50s over the mountains of SE WV into far SW VA.
Previous discussion from early morning...
Low pressure was over the Central Appalachians this morning with
a weak boundary roughly parallel to the ridges. Short wave on
the Dakotas as seen on the water vapor loop will deepen the long
wave upper trof over the northeast United States tonight and push
the low offshore as it deepens. Winds come around to the northwest
tonight as the low moves of the coast. The 850 MB front also
crosses through the Mid Atlantic region tonight with winds
increasing into the 30 to 35 knot range by Saturday morning.
Models were showing most of the cloud cover below 700MB today with the
most cloud cover over the mountains. Once the wind comes around
through a deep layer tonight, clouds will clear out east of the
Blue Ridge and lower upslope clouds will increase on the western
slopes.Have kept a low probability of precipitation in southeast
West Virgina tonight.
Expect enough sun today in the foothills and piedmont for maximum temperatures
to be bout 10 degrees above normal. Went slightly above MAV
guidance in the east and lower than guidance in the west where more
cloud cover is expected. Stayed close to MAV guidance for
lows tonight. Cold advection begins after 00Z behind the 850MB
front and air mass on Bufkit at Lewisburg gets cold enough for
snow showers after 06Z/1AM.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 300 AM EST Friday...
Upper trough over the East coast Saturday will transition east to
the Atlantic ocean by Sunday night. Surface cold front will push
east out into the Atlantic ocean. A shortwave rotating around the
upper trough will create some western upslope clouds and perhaps
isolated rain or snow showers along the higher ridges of western
Greenbrier Saturday morning. Cloud cover will decrease as the day
progresses and winds will increase across the mountains Saturday
afternoon with modest pressure gradient. High temperatures
Saturday will range from the mid 30s in northwest Greenbrier county
to the upper 50s in the Piedmont.
Winds will subside Saturday evening into saturday night as a cool
dry high pressure builds east across the region. It will be cold
Saturday night with low temperatures from the mid 20s in the
mountains to around 30 degrees in the Piedmont. High pressure will
build east across our area Sunday into Sunday night. The upper
ridge will build east across the region. Sunday afternoon
High temperatures will vary from around 40 in the mountains to the
mid 50s east of the Blue Ridge.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 330 AM EST Friday...
The Gulf will open up and provided welcome rains for the long
range period. 1022 mb surface high pressure will move east and off
the Virginia coast Monday afternoon. The heights increase aloft
with an upper level ridge axis centered over the Appalachian
Mountains by 00z Tuesday. Southerly winds ahead of the approaching
cold front to the west will produce a warm afternoon with high
temperatures Monday from the upper 40s in the Northwest mountains
to around 60 degrees in the Piedmont. High temperatures could be
warmer depending on the amount of prefrontal cloud cover.
Increased pops for Monday night as cold front approaches from the
west associated with the low center lifting northeast into the Great
Lakes Region. A wave and the cold front slowly moves east Tuesday
into Wednesday, then pushes east of the area Wednesday night into
Thursday. The timing is a little slower on GFS compared to ECMWF.
In any case, both models are advertising a good soaking rain of 1 to
2 inches possible. High pressure builds east out of the Tennessee
valley and moves across our area Friday.
Temperatures will run warmer than normal Monday into Wednesday, then
fall back to near normal levels by Friday.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
As of 655 AM EST Friday...
Weak low over the Central Appalachians and surface front extending
to the Gulf Coast will move little today which will result in
light winds across southwest Virginia, southeast West Virginia and
northwest North Carolina. High confidence that the front will move
east after 00Z/7pm with winds becoming northwest and winds speeds
increasing especially at higher elevations.
Low confidence about amount of cloud cover today. HiRes models as
well we NAM/GFS suggest more cloud cover over the mountains.
Overall expect ceilings in the 4-6KFt range for much of the day.
Once upslope winds pick up speed through a deeper layer...there
may be enough lift to isolated to scattered rain or snow showers
in southeast West Virginia. Coverage not extensive enough and
probability not high enough to include in the KBLF or KLWB taf at
this time. Experimental HRRR suggests smoke from fire in northern
Amherst County VA may get into KLYH around 00Z/7PM. Confidence is
low of impact at the airport but flights closer to the fire should
expect MVFR visibility, possibly lower, today and tonight. Other
large fire continue in northwest North Carolina, so pockets of
MVFR or lower visibility likely there as well.
Observations indicating some MVFR fog across southern Virginia
this morning, but this will dissipate by 14Z/9AM.
Extended aviation discussion...
Aside from upslope lower cigs at KBLF and possibly KLWB Saturday will
see VFR elsewhere from Saturday through Monday. The next system
arrives from the southwest and will bring widespread rainfall to
the area by Tuesday along with lower cigs and vsbys.
&&
.FIRE WEATHER...
As of 415 AM EST Friday...
Winds will gradually turn to the northwest tonight behind a front with
increasing wind speeds. Wind gusts at higher elevations,especially
along the southern Blue Ridge may reach 30 mph by Saturday
morning. Wind will diminish by Sunday and become light from the
southwest Sunday night with high pressure over the region.
Minimum humidity today will be 50 to 60 percent in the foothills
and piedmont and 60 to 70 percent in the mountains. Drier air
will come in behind the front on Saturday, lowering afternoon
humidities. By Sunday afternoon humidity values will be from 30
to 40 percent.
Precipitation chances increase late Monday night and continue through
Wednesday night. The best chance for a soaking rain will
be Wednesday and Wednesday night with a good potential for one to
two inches of rainfall across the area.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...KK
LONG TERM...KK/RCS
AVIATION...AMS/JH
FIRE WEATHER...AMS
Area Forecast Discussion
National Weather Service Wakefield VA
338 PM EST Fri Nov 25 2016
.SYNOPSIS...
An area of low pressure lifts northeast across the Carolinas and
Southeast Virginia this evening ahead of a cold front, which
crosses the Mid-Atlantic region late tonight. High pressure
builds into the region over the weekend, and slides offshore
early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Mid-afternoon weather analysis reveals a stationary frontal
boundary/sfc trough oriented west to east just south of the local
area, parallel to flow aloft. A weak wave of low pressure has
developed across the Western Carolinas and will lift NE through
this evening. Aloft, low amplitude upper ridge has nudged
offshore, as a shortwave trough continues to nudge east from the
Ohio Valley toward the central Appalachians this afternoon.
The aforementioned upper trough drops into the Ohio Valley this
evening, with Sfc front to the south to remain quasi-stationary
for the balance of the day until it gets nudged farther south by
the trough tonight. No real forcing mechanism for any showers
thus far, and expect rain chances will increase over the next few
hours across the Northern Neck and Lower Eastern Shore...and into
early this evening for Hampton Roads/NE NC. High end chance pops
continue in expectation of scattered showers. HRRR and 12z/GEFS
plumes have each inched up QPF to between a tenth and a quarter
inch tonight through 12z, mainly along the coast from ECG to OXB,
which is coincident with best lift/moisture. Time-lagged NARRE and
High-res models indicate that we`ll likely see some patchy fog in
most spots early on tonight, even inland before better mixing
arrives with as the second, stronger front pushes in late
tonight. Thus, will go with fog early/clearing trend late across
the piedmont and west of I-95, with fog/clouds and a sct shra or
two to linger near the coast through around sunrise Saturday
morning. Forecast lows range from the upper 30s nw, to the upper
40s/low 50s se.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
Front will be offshore to start the day Saturday, with quick
clearing as drier and seasonably cool high pressure builds in
from the nw through the day. Breezy and cooler...as 850mb
temperatures drop to 0 to -4C. Local thickness tools and numerical
guidance values mesh well for max temps, both indicating highs in
the lower to middle 50s (mid to upper 50s well inland) under a
partly to mostly sunny sky.
A clear sky, diminishing winds and high pressure to our immediate
SW will allow for a seasonably cool night Saturday night. Look for
early morning low temps in the low to mid 30s inland and interior
Eastern Shore...35 to 40 along the immediate coast.
High pressure builds across the Southeast Conus Sunday and Sunday
night, upper ridging builds aloft. Temps will begin to moderate as
llvl flow turns back around to the w-sw Sunday and Monday. Northwest
flow aloft will likely bring a bit more in the way of mid-level
clouds, especially NE portions but dry conditions will continue to
prevail. Forecast highs are in the low/mid 50s Sunday...mid to
upper 50s (around 60 South) Monday. Early morning lows mainly in
the mid to upper 30s Monday and Tuesday mornings.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Weather pattern starts to shift early in the extended with the
upper ridge sliding offshore resulting in increasing mid and upper
level moisture ahead of an approaching storm system. Dry
conditions persist for most areas Monday night but clouds will be
on the increase.
A broad upper level trough over the central portion of the country
will push east Tuesday and Wednesday, dampening as it approaches
the Mid-Atlantic. Medium range model consensus pushes precip into
the local area Tuesday afternoon. Expect scattered showers and
rather low QPF in general with this first impulse. Once again,
appears cold front looks as though it will hang up and linger
near the mountains into the Piedmont until a more potent
shortwave embedded in the upper level trough lifts from the lower
Mississippi River valley into the Ohio Valley Wednesday night
into early Thursday. Temps ahead of the front Tuesday and
Wednesday will average above normal with highs in the 60s to
around 70.
The deep layer southwest flow and 850mb v-anomalies around +1
standard deviation will result in increasing moisture late
Wednesday ahead of the front. Moisture and favorable upper level
dynamics will result in perhaps the best chance of meaningful
rainfall in several weeks. POPs increase Wednesday into Wednesday
night, with likely POPs Wednesday. ECMWF has come into better
agreement with the GFS pushing precip off the coast by Thursday
afternoon. Will keep mention of slight chance to low end chance
POPs along the coast Thursday to account for uncertainty.
Behind the frontal passage...much cooler Thursday, with high in
the 50s to near 60 and high in the low to mid 50s Fri and Sat.
Overnight lows will also drop from the low to mid 30s Thu night
and Fri night.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Predominate VFR conditions across the terminals this afternoon, as
bkn mid-level cigs will persist through early evening. Thereafter,
expect deteriorating conditions once again this evening, ahead of
a cold front approaching from the nw. Weak low pressure currently
across the western Carolinas will swing NE across southern
terminals tonight, bringing a chc of scattered light rain showers
mainly after 00z, primarily for ORF/ECG/SBY, however vicinity
shower wording has been included at PHF. MVFR to LCL IFR
conditions expected early tonight, again mainly for se VA/ne NC.
CIGS should improve overnight after midnight at RIC and after
08-10z late tonight at SE coastal terminals as drier air arrives into
early Saturday. A nnw wind will gust up to 20-25kt along the coast
late tonight into Saturday morning during this period as sfc high
pressure builds into the area. Gusts to 15-20 kt will continue
at SBY/ORF/ECG through Sat aftn before diminishing.
OUTLOOK: High pressure builds over the region Saturday night into
Sunday, before sliding off the coast Sunday night into Monday. A
slow moving cold front approaches from the west later Tuesday.
&&
.MARINE...
Winds and waves continue to remain rather calm this afternoon.
Some areas of patchy fog are possible this evening along the
Eastern VA rivers and Chesapeake Bay...but any fog which tries to
develop will not be longed lived as a cold front pushes across
the area by daybreak. Sct showers are possible ahead of the front
tonight, especially across the lower Bay and coastal waters this
evening.
The front crosses the Bay after midnight and pushes off the coast
around 6 am, followed by a rapidly tightening pressure gradient
resulting in a decent nnw surge of colder air just before
daybreak into Saturday morning. NW winds of 18 to 20 kt with
higher gusts will impact all waters Sat morning, followed by a
secondary nw surge Sat evening. The NW winds do not start to
gradually diminish until Sunday morning. SCA flags have been
issued for all waters based on above timing/distribution.
Mariners should expect winds of 20-25kt Bay/ocean (gusts up to
30kt from Parramore Island to Currituck Light) Sat morning and
15-20kt Sound/Rivers. Waves in the Bay quickly build to 3-5ft
during the initial cold air surge...while seas over the ocean
average 3 ft late tonight but then quickly build to 5 to 6 ft Sat
morning and persist through early Sat evening before slowly
subsiding Sat night. Please refer to the Marine Weather Message
(WBCMWWAKQ) for more specific details for each marine zone.
High pressure returns to the region Sun night into Mon before
sliding off the Carolinas Mon evening. A warm front slowly lifts
through the area late Mon night into early Wed as a potent low
pressure system dives across the Desert SW into TX and then tracks
into the TN Valley on Wed...merging with a more stationary low
sitting over the upper Midwest. This appears to be a very dynamic
merger and solid SCA conditions may be possible as early as Tue aftn
ahead of incoming precipitation and potentially persisting through
early Thu before conditions subside (generally s winds 15-25kt/seas
5-7ft/waves 3-4ft). This particular system will need to be monitored
closely.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 4 AM to noon EST Saturday for
ANZ635>638.
Small Craft Advisory from 1 AM Saturday to 7 AM EST Sunday for
ANZ630>632-634.
Small Craft Advisory from 4 AM Saturday to 7 AM EST Sunday for
ANZ633.
Small Craft Advisory from 4 AM to 11 PM EST Saturday for
ANZ650-652-654-656.
Small Craft Advisory from 4 AM Saturday to 4 AM EST Sunday for
ANZ658.
&&
$$
SYNOPSIS...AJZ/MAM
NEAR TERM...MAM
SHORT TERM...MAM/AJZ
LONG TERM...SAM/JAO
AVIATION...MAM
MARINE...JO
Area Forecast Discussion
National Weather Service Bismarck ND
301 PM CST Fri Nov 25 2016
.SHORT TERM...(This evening through Saturday)
Issued at 301 PM CST Fri Nov 25 2016
Mild and dry weather will continue through Saturday, though it
will be seasonably cold again tonight.
Broad 500 mb ridging will remain in control of the weather across
the region tonight and Saturday, though a weak mid-level shortwave
trough depicted as a shearing zone of positive vorticity advection
moving from eastern MT this afternoon and across ND tonight should
act to flatten the ridging. Even so, high-level clouds which have
largely been originating as a so-called "Chinook Arch" downstream
of the Northern Rocky Mountains may decrease behind the weak wave
by Saturday, and the 12 UTC model guidance is in good agreement on
warming at 850 mb, both favoring an even warmer day tomorrow. That
12 UTC multi-model consensus calls for 850 mb temperatures ranging
from +5 C at Rolla to +7 C along the Missouri River and +10 C over
far southwestern ND by late Saturday afternoon.
In general, we relied on the 12 UTC multi-model consensus fields
to construct the short term forecast. However, we did rely on the
colder edge of MOS-based guidance for low temperatures tonight in
respect to recent forecast biases and the observed boundary layer
drying that has occurred this afternoon (dewpoints are mainly 15
to 25 F as of 20 UTC). We also relied on the warmer edge of MOS
(and in particular 12 UTC GFS-based MOS) for high temperatures on
Saturday in respect to largely snow-free ground and trends today.
However, light and mainly southerly surface flow on Saturday does
drive some uncertainty in how much mixing and warming may occur.
Finally, we did include patchy fog in the forecast tonight through
early Saturday morning over parts of McIntosh and Dickey Counties
from Ashley toward Ellendale. Visible satellite images reveal snow
on the ground in those areas, which is undergoing melting today,
and RAP and HRRR sounding profiles viewed in BUFKIT suggest low-
level turbulence will be small enough to support fog. Recent HRRR
iterations also simulate fog in those areas.
.LONG TERM...(Saturday night through Friday)
Issued at 301 PM CST Fri Nov 25 2016
The weather is forecast to be fine for post-holiday travel during
the day Sunday. However, accumulating snow, gusty winds and colder
weather is possible early next week. Snow potential will increase
as early as Sunday night and Monday morning with possible impacts
to the Monday morning commute, especially across central ND.
The 12 UTC deterministic and ensemble global model guidance stayed
the course showing a negatively-tilted upper-level trough ejecting
into the High Plains late Sunday before closing off aloft and then
slowly meandering across SD and MN Monday and Tuesday in response
to strong downstream blocking at 500 mb. Guidance even suggests a
temporary rex block may develop with a cut-off 500 mb high forming
across the Hudson Bay region early next week. This teleconnects to
a slow-moving trough and potential winter storm across the region.
The 12 UTC GFS and ECMWF continued to provide support for a very
deep surface low of 975-979 mb somewhere near the ND/SD/MN border
region by Monday morning as the deep cyclone becomes stacked. The
12 and 00 UTC NAEFS output forecast sea level pressure values at
the minimum for late November and early December, which is telling
both from the perspective of the sytem`s strength, and also with
regard to the ensemble support for its overall evolution. We feel
that the forecast timeframe may indeed have already moved inside
of the predictability horizon that`s dictated by initial-condition
sampling as the synoptic-scale wave placement is rather clustered.
That is not to say that uncertainty in details doesn`t exist, even
with the placement of the 500 mb low (the ECMWF is both slower and
further southwest than the GFS), but overall, confidence is
increasing with regard to potential accumulating snow beginning
Sunday night or early Monday.
The 12 UTC GFS, ECMWF, and NAM all supported a strong, 50 to 60 kt
low-level jet transporting seasonably-rich moisture poleward into
the region Sunday night with precipitable water values rising to
0.75 inches in eastern ND. Strong dynamic forcing associated with
the deepening trough will readily yield precipitation, though the
system will be relatively warm with the 850 mb 0 C isotherm and
thus a rain-snow line possibly lingering over east central ND and
the James River valley all the way into Monday. Synoptically, this
setup could favor a band of accumulating and possibly heavy, wet
snow west of that baroclinic zone, potentially over central ND. It
is too soon to write home on the details of that, but overall the
trend in the last 24 hours of model cycles has been to focus that
initial band of potential snowfall further west, and along the
Highway 83 corridor late Sunday night into Monday. Thereafter, as
the stacked low slowly meanders eastward through midweek we could
experience a prolonged period of lighter snowfall resulting from
persistent mid-level theta-E advection northwest of the cyclone.
It`s during that period, when large-scale moisture transport will
largely be cut off from the wave, that current model QPF output
could potentially end up being biased too high.
The 12 UTC GFS ensemble plume guidance continued to show a rather
large spread in liquid-equivalent moisture totals across the area,
but interestingly enough many members of the guidance are wetter
than the mean. Only a small set of the ensemble pack now suggests
little in the way of potential snowfall in central ND, especially
with the primary wave of moisture transport and forcing from late
Sunday night into early Monday.
Impacts will likely be felt from this round of winter weather, but
snow-to-liquid ratios will be relatively low given the relatively
warm nature of the system, and the resulting high-density snow may
not produce much blowing snow per the Baggely blowing snow model.
Moreover, road sub-surface temperature are near 40 F, which means
high snowfall rates will likely be required to yield accumulations
on road surfaces. This may overall limit the severity of impacts
to travel, but commerce may end up being more impacted because of
the recent stretch of very warm and dry weather that`s allowed for
outdoor projects to continue almost unchecked. True to that point,
through November 24th, this is Bismarck`s warmest November on
record, and we haven`t seen any snowfall of significance yet.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 301 PM CST Fri Nov 25 2016
A Surface low pressure system in Alberta will track slowly east.
This will maintain a dry southerly flow in the region. VFR
conditions are expected to prevail across the northern plains
through the 18Z TAF period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...WAA
Area Forecast Discussion
National Weather Service Lincoln IL
236 PM CST Fri Nov 25 2016
.SHORT TERM...(This evening through Saturday)
ISSUED AT 236 PM CST Fri Nov 25 2016
Main question in the short term is the cloud trends tonight. Clouds
have been pretty persistent, but latest visible satellite imagery
and a check of area webcams indicates some thinning of the clouds is
taking place along the I-72 corridor and also just north and west of
Peoria. The western flank of the cloud shield also has made steady
eastward progress today. The midday run of the HRRR is doing a
reasonable job with the cloud edge, but largely keeps the CWA cloudy
past midnight aside from some breaks in the far southwest. As such,
will keep mostly cloudy conditions going through the night from
about Peoria-Flora eastward, with partly cloudy skies to the west by
mid evening. Despite the clouds, temperatures should be colder
overnight than this morning, as a surge of colder air drops in
behind the shortwave currently swinging through Wisconsin and
northern Illinois. Went with lows in the lower 30s over the entire
CWA, but some 20s are not out of the question across the west where
the skies clear out.
A ridge of high pressure will drift east across the Mississippi
Valley on Saturday, pushing out the remainder of the clouds as a
surge of milder air pushes eastward. Much of the CWA should reach
the lower 50s, coolest east of US-51 where the clouds will stick
around the first part of the day.
&&
.LONG TERM...(Saturday night through Friday)
ISSUED AT 236 PM CST Fri Nov 25 2016
Forecast models look quite similar at the beginning with the next
weather system, which is expected to bring precip to the CWA for the
latter part of the weekend and the first part of next week. As the
surface low pressure area moves out from the eastern Rockies and
into the northern plains tomorrow night, warm and moist air will
advect northward into the area Sunday morning. Precip is expected to
develop west and southwest of the area during the morning and then
spread into the western part of the CWA Sunday afternoon. Just
showers are expected since the best instability should be west of
the area, closer to the actual frontal system in the plains.
Showers should become more numerous and widespread over the area
Sunday night. The precip is expected to come in two waves with the
Sun night precip being the first wave. After a lull in the precip
Monday morning, the second wave will arrive in the area Monday
afternoon and continue through Monday evening, and be associated
with the main cold front that should push through the area Monday
night. Most of the models bring the heaviest precip associated with
the second wave across the eastern and southeastern part of the CWA,
while the NAM brings it northeast along I-55. Since this is the
first run of the NAM that does this, will maintain the trend of the
heaviest rain moving across eastern and southeastern IL Mon
afternoon through Mon evening, which this agrees well with HPC QPF
forecast. However, if other models trend back to west in later
forecast, do not be surprised to see an adjustment in that
direction. Throughout the whole CWA, from Sun night through Mon
night, QPF forecast looks to be around an inch with some areas
approaching 1.25 inches, mainly in the southeast and possibly along
the Illinois river. Not expecting any headlines at this time, but
brief heavy rainfall combined with clogged drains could create some
localized flooding Monday afternoon through Monday night. In
addition to the possible heavy rainfall, models forecasting some
minor instability in the area for Monday afternoon and evening, with
some elevated instability as well. So have added slight chance
thunder in for forecast for those two periods. However, it will not
get mentioned at this time in the worded forecast.
This precip associated with this weather system should push
northeast and east of the area quickly Monday night, resulting in
dry weather for Tue through Wed. Models then show some differences
again Wed afternoon and Wed night with the GFS showing dry weather
and the ECMWF and CMC showing another wave riding up the cold front,
bringing more precip to southeast IL. First time models are showing
this and with the differences, will just have slight chance of
precip during that time period in southeast IL...which will not be
mentioned in the worded forecast at this time. The remainder of the
week should then be dry as the flow becomes more zonal and the upper
level system sits over the Great Lakes region.
Temps will be quite warm, above normal, for Sunday and Monday, and
even into Tuesday. Then the cooler, more seasonable temps will
return after the system for Wed through Fri.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1135 AM CST Fri Nov 25 2016
Main issue is with any clearing of the the stubborn MVFR ceilings
that continue to plague the area. Back edge of the clouds continue
to march east through Iowa/Missouri, but forecast soundings and
simulated satellite imagery continue to show central Illinois
remaining in the clouds overnight into Saturday morning. Some
potential for VFR conditions by late evening in parts of the area,
but have kept the ceilings below 3,000 feet at KCMI into Saturday
morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Auten
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
221 PM EST Fri Nov 25 2016
.SYNOPSIS...
A cold front will move through late tonight and early Saturday
morning. High pressure will build over the area this weekend. The
next cold front will move through the area Wednesday night into
Thursday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 220 PM Fri...Latest analysis shows cold front extending
through the NC piedmont and down into the FL panhandle. The front
will push eastward and move through Eastern NC late tonight and
early Saturday morning with strong CAA and breezy N/NNW winds
developing. Latest radar imagery shows little returns, just a few
sprinkles across central NC. High res models, HRRR and NSSL WRF,
continue to show shower activity blossoming tonight ahead of the
front. Will continue chance pops, with best chances after 03z.
Precip should taper off from west to east early Sat morning.
Challenging fog forecast overnight with cloud cover and light
winds. Think some areas could see patchy fog develop early ahead
of the front, then dissipate with increasing winds late tonight
and early Saturday morning. Overnight lows in the upper 40s to mid
50s.
&&
.SHORT TERM /SATURDAY/...
As of 220 PM Fri...The front will push offshore early Saturday,
as strong high pressure builds in from the west. Good CAA develops
behind the front with breezy northerly winds along the coast.
Early morning low clouds should lift by late morning, early
afternoon. Low level thickness values support highs several
degrees cooler than the past few days with temps in the mid 50s to
around 60 degrees.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 240 AM Friday...Mainly dry weather is expected through
Monday with increasing chances for precipitation beginning Tuesday
with the best chances for significant rainfall Wednesday and
Wednesday night, possibly extending into Thursday.
Drier and much cooler weather expected late weekend as high
pressure builds over the area. A slow moving and complex frontal
system will approach from the west and produce better chances for
significant rainfall Wednesday and Wednesday night while
temperatures moderate to normal levels Monday and above normal
Tuesday and Wednesday. There are some model differences between
the GFS and ECMWF with the frontal passage next week. The GFS is a
good bit faster that the previous ECMWF. The 00Z ECMWF has sped up
slightly, but is still slower with the frontal passage, allowing a
chance of precipitation lingering into Thursday. Give
uncertainties in timing did not go over 50 PoPs through the
extended.
Below normal highs in the 50s for Sunday warming back into the
60s Monday as high pressure slides off the coast allowing for
return southerly flow. Temperatures will warm further Tuesday and
Wednesday into the 70s and precipitation chances will be
increasing as southerly flow strengthens in advance of the next
frontal system. Will have a cool down behind the next front with
temperatures dropping into the upper 50s to near 60 by Friday with
lows near 40 inland to around 50 on the coast.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Short Term /through Saturday/...
As of 1240 pm Fri...High confidence of VFR conditions through
tonight. Scattered to broken cloud deck with light and variable
winds and scattered rain showers tonight. Forecast soundings and
numerical guidance indicating fog developing ahead of the cold
front for PGV and ISO tonight. Front will cross the area early
Saturday morning with winds becoming northerly and IFR ceiling
conditions developing. Flying conditions will slowing improve
throughout the day...expect VFR conditions to return late
morning/early afternoon.
Long Term /Saturday night through Wednesday/...
As of 240 AM Friday...Mainly VFR conditions are expected through
Monday with high pressure prevailing. The chance of some scattered
showers will begin to increase Tuesday and become higher on
Wednesday as a cold front approaches the area. There will be a
chance of MVFR and brief periods of IFR possible mainly in heavier
showers that could develop Wednesday.
&&
.MARINE...
Short term /through Saturday/...
As of 220 PM Fri...Latest obs show SE/SW 5-10 kt with seas 1-2
feet. Conditions will deteriorate quickly behind a cold front late
tonight and early Saturday as strong cold air advection develops.
The front will move through the waters late tonight and early
Saturday morning, with N/NNW winds increasing to 15-25 kt and seas
building to 4-7 feet north of Lookout and 3-5 feet south. SCA
continues north of Cape Lookout, and added the sounds and
Alligator river with frequent gusts to 25 kt Sat.
Long Term /Saturday night through Wednesday/...
As of 240 AM Friday...Small Craft Advisory continues for the
coastal waters from from Cape Hatteras North. Seas will build to
4 to 6 ft Saturday into Sunday with the highest seas over the
northern and central waters, where some 7 foot seas are possible.
Winds will diminish to 10 KT or less Sunday Night into Monday with
seas subsiding from 2 to 4 ft to 1 to 3 ft. Southerly flow ahead
of the next front will increase Tuesday into Wednesday and small
craft advisory conditions will again be possibly by Tuesday Night
continuing through Wednesday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 6 AM to 4 PM EST Saturday for AMZ130-
131-135.
Small Craft Advisory from 6 AM Saturday to noon EST Sunday for
AMZ150-152-154.
Small Craft Advisory from 8 AM to 6 PM EST Saturday for AMZ156.
&&
$$
SYNOPSIS...CQD/HSA
NEAR TERM...CQD
SHORT TERM...CQD
LONG TERM...RSB
AVIATION...RSB/BM
MARINE...RSB/CQD
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
357 PM CST Fri Nov 25 2016
.SHORT TERM...(This evening through Saturday)
Issued at 356 PM CST Fri Nov 25 2016
Main issue during the short term is what happens with stratus
tonight. On the 12z MPX sounding, the stratus went up to about 800
mb, or 5600 ft AGL, hence why it has been so slow to move across
southern MN and has even stalled across central MN. Given current
dewpoints in the low and even mid 30s, chief concern tonight will
turn to fog potential. We should achieve our cross over
temperatures within 3 hours of sunset and spend the next 9ish
hours with temperatures below the cross over temperature, which
means dense fog could become a significant issue on the west edge
of the stratus field. Right now, followed a blend of hi-res model
visibility forecasts to get fog into the weather grids. This
resulted in the strongest fog mention extending from central MN
into southeast MN, or near where the west edge of the stratus
field will likely setup. Other change to the forecast for tonight
was to increase lows 3-5 degrees thanks to the current dewpoints
and expected cloud cover/fog tonight helping keep temperatures
warmer than what most of the guidance has depicted. Our diurnal
temperature ranges the last 3 days have been minimal (less than 5
degrees) and don`t anticipate temperature drops as large as what
the majority of guidance would have to achieve the lows they have
for tonight. What we have going right now most closely resembles
lows forecast from the RAP.
For Saturday, we are currently expecting the stratus to finally
clear the area, but would not be at all surprised if the stratus
hung tight in western WI. Though we may lose the stratus, dense
cirrus/cirrostratus moving across the Dakotas today will be over
us tomorrow, so we will just be replacing the low clouds with high
clouds. For highs, we will see 925mb temps increase to between +2C
and +6C. This is what we are seeing today in eastern SD, where
temperatures easily climbed into the mid 40s and this is what we
basically have south of I-94 Saturday, a good 10 degrees above
normal.
.LONG TERM...(Saturday night through Friday)
Issued at 356 PM CST Fri Nov 25 2016
The big story for the long term continues to be a potent Plains
storm system this weekend that eventually closes off over
Minnesota early next week with lingering rain/snow showers and
extensive cloud cover for the rest of the week.
Rain will rapidly develop over the central Plains Sunday morning
in response to strong moisture advection and 1 to 1.25 inch pwats.
That maturing rain shield will be lifting into Minnesota late
Sunday afternoon and across the rest of the region Sunday evening,
before exiting to the north late Sunday night or early Monday. A
few embedded thunderstorms are also possible given neutral
stability. Rainfall amounts of 1/2 to 3/4 inch are likely.
Temperatures will rise steadily Sunday night as moisture
increases. The dry slot will reach southern half of Minnesota
Monday morning which could dry the column enough for some sun.
Good mixing with gusty winds should bring a pretty mild day with
highs in the 50s along and east of I-35 unless the dry slot
doesn`t progress as far north and east as the ECMWF indicates.
The rest of the forecast will depend on where the system closes
off. If this occurs northwest of the area, the dry slot will
linger longer across south central MN to west central WI. If it
closes off overhead or to the east, almost continuous light
rain/snow showers are likely for much of the week. Continued the
low chances for much of the area, with the highest PoPs (40-50
percent) across western and central MN.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1136 AM CST Fri Nov 25 2016
Back edge of stratus continues to make slow, yet steady progress
east. 12z MPX sounding showed it is rather thick though, so did
delay clearing a few hours. In fact, it is looking likely that EAU
will not see it go away, with current IFR stratus going MVFR this
afternoon and going back to IFR tonight. Big concern though with
this clearing is the potential for fog. The HRRR has been
aggressive with developing fog this evening west of the stratus
field and followed that idea for hitting AXN/STC in particular
hard with the fog mention. Given the recent snowmelt and dewpoints
currently in the 30s and no significant push of dry low level air
coming tonight, find it hard to not believe what the HRRR vis
forecast has. Once we get rid of the fog/stratus Saturday morning,
it will remain cloudy, though with the mid/upper clouds currently
moving into the western Dakotas.
KMSP...Given how thick the stratus was this morning, we are
concerned that even 00z may be to early for the stratus clearing.
Once the stratus does clear, we will have mainly clear skies with
light south to southeast winds overnight. Radiation fog is pretty
rare for MSP, but given how moist we are right now, tonight will
be one of those few nights where we could see it.
/OUTLOOK FOR KMSP/
Sun...Mainly VFR. MVFR/IFR with -SHRA late. Wind SE 10-15 kts.
Mon...MVFR early with -RA. Wind S 10-15 kts.
Tue...MVFR/IFR. Chc -RA/-SN. Wind SW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...MPG
LONG TERM...BORGHOFF
AVIATION...MPG
Area Forecast Discussion
National Weather Service Morristown TN
252 PM EST Fri Nov 25 2016
.SHORT TERM (This Afternoon through Saturday)...
Current water vapor imagery and RAP upper air analysis indicates an
upper level trough moving across the Upper Midwest southeastward
into the Ohio River Valley. At the surface, the cold front is now to
the south and east of the area stretching southward across the
Carolinas into the northern Gulf of Mexico. Drier air is moving in
behind the system but a shallow layer of low level moisture has
produced widespread cloud cover across the forecast area. As
mentioned in previous discussions, this cloud cover stretches well
back to the west of the Mississippi River.
For tonight, the upper level trough will swing through the Southern
Appalachians but the atmosphere will be too dry for precipitation.
Northwesterly winds tonight will remain elevated in the 5-10 mph
range with surface low pressure along the Eastern Seaboard and high
pressure across the Mid-Mississippi River Valley. The main
challenge overnight will be sky cover and temperatures. The NAM
maintains the shallow layer of low-level moisture throughout the
overnight hours with widespread cloud cover continuing. The
synoptic models are more aggressive with clearing things out
tonight. For now, have sided more with the cloudier model solutions
overnight with additional orographic lift from the northwesterly
flow as well. With this, also increased overnight lows by about 3-5
degrees due to the winds and clouds preventing radiational cooling.
In addition, the cold air advection is not overly impressive with
850 mb temperatures around 0 deg C in SW VA. Do not expect any fog
formation overnight with the winds remaining elevated. Skies should
eventually begin to clear during the day tomorrow with surface high
pressure building in from the west. PW values are forecast to be
around a quarter of an inch. High temperatures will be near to
slightly below average tomorrow with highs ranging from upper 40s
to upper 50s for most valley locations.
.LONG TERM (Saturday night through Friday)...
Much needed rainfall will occur during this period as the upper
pattern becomes much more favorable than previous weeks.
Saturday night and into Sunday the area will be under the influence
of the surface/upper ridge. Expect smoke from area fires to be a
problem likely reducing air quality. Thankfully the ridge will be
progressive moving east by Monday morning.
On Monday, southerly winds will bring in warm air and increasing low
level moisture ahead of the deepening trough over the southern
Plains. It will become breezy Monday afternoon and downright windy
Tuesday night particularly for the mountains and adjacent foothills.
Will continue with mention in the HWO to account for the strong
winds.
Besides the wind, beneficial rainfall chances will increase
later Monday afternoon into Tuesday morning. A short drying period
will occur Tuesday before another shortwave translates over the
region. This will likely occur later Tuesday afternoon through
Wednesday with isolated to scattered thunderstorms possible. Expect
rainfall chances to taper off late Wednesday night into Thursday
morning. Some of the rainfall Tuesday night could be heavy at times
and total rainfall (from Monday through Thursday) could exceed three
inches (and maybe more in the southern TN valley).
This brief wet period will begin to dry out through next weekend.
Looking farther ahead...another chance for rainfall could occur
before the end of the weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 39 58 32 62 / 0 0 0 0
Knoxville McGhee Tyson Airport, TN 37 53 28 59 / 0 0 0 0
Oak Ridge, TN 37 54 28 60 / 0 0 0 0
Tri Cities Airport, TN 35 48 24 58 / 10 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
MA/AC
Area Forecast Discussion
National Weather Service Tulsa OK
344 PM CST Fri Nov 25 2016
.DISCUSSION...
High pressure at the surface will continue to build across the
area tonight, setting the stage for ideal radiational cooling
conditions in many locations. Current dew point temps in the mid
30s - lower 40s should be easily crossed over leading to
widespread fog, likely dense in many locations. Last several runs
of operational and experimental HRRR continue to support this,
with legitimate threat of freezing fog across northeast
OK/northwest AR. Will thus go with a freezing fog advisory from
about i-40 north 06z-15z. Conditions improve after mid morning
Saturday with winds eventually returning out of the south.
Next issue involves precip chances later in the weekend into
Monday as system off the California coast this afternoon lifts
northeast across the plains. Modest low level moisture return will
take place to our west by Sunday, but overall quality of moisture
return is not impressive. Will eventually begin to see scattered
showers and a few elevated storms late Sunday as stronger synoptic
forcing associated with approaching low spreads across southern
plains. Instability will remain limited due to above mentioned
moisture issues, plus the bulk of cooing aloft will stay to the
north. A secondary wave rotating around base of trough Sunday
night and MOnday should be able to tap into better quality
moisture across southeast OK by late Sunday night and Monday
morning, at which time the highest rain chances will be carried.
Front sweeps through Monday another stretch of dry weather
lasting through Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 33 62 48 61 / 0 0 0 50
FSM 36 64 42 61 / 0 0 0 20
MLC 34 63 49 63 / 0 0 0 40
BVO 26 61 45 61 / 0 0 0 50
FYV 30 59 43 57 / 0 0 0 30
BYV 32 59 43 57 / 0 0 0 20
MKO 32 62 45 61 / 0 0 0 40
MIO 30 60 44 59 / 0 0 0 50
F10 33 63 48 62 / 0 0 0 40
HHW 38 63 46 65 / 0 0 0 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Freezing Fog Advisory from midnight tonight to 9 AM CST Saturday
for OKZ054>071.
AR...Freezing Fog Advisory from midnight tonight to 9 AM CST Saturday
for ARZ001-002-010-011-019-020.
&&
$$
SHORT TERM...07
LONG TERM....14