Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/07/17
Area Forecast Discussion
National Weather Service Burlington VT
702 PM EST Mon Nov 6 2017
.SYNOPSIS...
Rain over southern Vermont will come to an end early this
evening as a cold front exits the area to the east. We will
still keep quite a bit of clouds around tonight with northwest
winds bringing colder air into the region. High pressure builds
into the region Tuesday into Wednesday for dry weather...but
below normal temperatures. We briefly return to normal conditions
on Thursday...but a trough of low pressure will bring a noticeable
change to our weather with rain showers changing to snow showers
and temperatures well below normal heading into the weekend.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
As of 643 PM EST Monday...Going forecast is in good shape with
just some minor tweaks made to sky cover for the overnight.
Latest HRRR has a very good handle on the areal coverage and
depth of 1000-850MB moisture currently driving the low clouds
across the region. Overnight, this moisture whittles away while
upstream moisture stays north of the region. Not thinking this
will have any effect on min temps, so left that intact.
Previous Discussion...Cold front has yet to push south of the
area this afternoon and as of 300 pm looks to be just south of a
Montpelier to Middlebury line. South of this line a fairly
widespread area of rain showers exists across south central and
southern Vermont and should last over the area until early this
evening when cold front finally moves east of the area. One item
of note for tonight is there is still quite a bit of cloud
cover over the area and feel it will not clear out as quickly as
some of the data suggests. So have a much slower timing of
clouds dissipating...but should eventually see some clearing
after midnight. Lows will generally get down into the mid 20s to
lower 30s with a few colder spots in the northern Adirondacks.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
As of 257 PM EST Monday...a large area of high pressure builds
into the region with dry weather expected through the entire
time period. Flow aloft will generally be from the west and
southwest through the period and temperatures will generally be
below normal. Should still have some cloud cover around on
Tuesday but Wednesday may be the day with more sunshine.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 331 PM EST Monday...While there are few timing
differences in the medium ranged guidance, the consensus is
setting up for an upper level trough to swing through just north
of the Great Lakes and develop a northern stream surface low
just north of the Ottawa valley. That low pressure system
deepens and brings a cold front through the North Country with
some light precipitation. Both the GFS/EC have the 0C 925/850mb
temps well to the south so any precip that falls should be snow.
The tightly packed thermal gradient will remain something to
watch for as there could be enough dynamical support to generate
some snow squalls but the good news with regards to impacts, is
that the timing of the front will move through overnight
limiting the overall impact of any such squalls.
Temps will also be something to continue focusing on as a 1038mb
high builds in over New York and New England and pushes the
925mb 0C line all the way to Virginia Friday night. Once again
there are some timing inconsistencies so I`ve stayed closer to
the more consistent EC with -6C to -12C at 925mb for lows Friday
night and highs on Saturday. That leads to lows in the teens
Friday night, highs in the 20s on Saturday except for areas near
Lake Champlain which should warm to near freezing, and then
single digits and teens overnight Saturday night.
The pattern quickly moderates as zonal flow takes over and we
warm back into the 40s for Sunday and Monday with lows in the
20s to 30s.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...Cold front has finally cleared the area.
MVFR ceilings continue through about 06z...before more
noticeable clearing takes place. Winds will generally be from
the northwest through the period at speeds of 10 knots or
less.
Outlook...
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Slight chance SHRA.
Thursday Night: VFR. Chance SHSN, Chance SHRA.
Friday: Mainly VFR, with local MVFR possible. Slight chance SHSN.
Friday Night: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Evenson
NEAR TERM...Evenson
SHORT TERM...Evenson
LONG TERM...Deal
AVIATION...Neiles
Area Forecast Discussion
National Weather Service Columbia SC
616 PM EST Mon Nov 6 2017
.SYNOPSIS...
High pressure in the forecast area will weaken tonight ahead of
an approaching cold front. The front will be near the north
part of the area Tuesday. It will sink just to the south
Wednesday. Wet conditions will be associated with the front
during the middle of week. Much cooler air will follow the
front.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Tonight a backdoor cold front will approach the extreme
northern portion of the forecast. Although moisture will be
increasing ahead of the front, we believe any showers will hold
off until Tuesday morning. The RAP model also suggests shortwave
energy will be moving east of the area late tonight which will
help suppress development. Dense fog tonight seems unlikely due
to increased mid-level cloudiness but cannot rule out some areas
of fog, particularly in the CSRA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
A frontal boundary will be near the northern portion of the
forecast area on Tuesday. Expect the greatest chance of showers
near the frontal boundary so have continued to indicate chance
pops north and slight chance south. Confidence is lower than
normal given the high spread in pop guidance. The MET has lower
pops and keeps the front further north than the MAV. Model
precipitable water values increase to around 1.6 inches by
Tuesday afternoon which is around 175 percent of normal for this
time of year. Instability appears weak Tuesday afternoon and
evening with model LI values around -1 to -2. Have continued
with mention of thunder Tuesday. It should remain warm south of
the front Tuesday with highs in the mid 70s to lower 80s. Models
show the boundary pushing south through the area Tuesday night
and early Wednesday. Shortwave energy will cross the area on
Wednesday enhancing rainfall potential. Have continued with
likely pops. It will be cooler on Thursday behind the front and
with clouds and rain in the area. Highs in the lower 60s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A southern stream trough will move from the Mississippi Valley
region toward the Southeastern states on Thursday and shift off
the coast on Friday. The frontal boundary will be along the
coast on Thursday. Deep moisture will shift off the coast late
Thursday into Friday as the trough pushes east. High pressure
will ridge into the region for Friday and Saturday providing
cool and dry conditions. Moisture may begin to increase toward
the end of the period on Sunday and Monday. Temperatures will be
near or below normal through the long term period.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
Increasing low-level moisture may again bring visibility
restrictions after 06Z Tuesday however mid-level cloudiness
advecting east from the Upstate may preclude widespread dense
fog. AGS and OGB will be the sites most likely to develop MVFR
or lower visibilities.
The backdoor front will approach the region late tonight and
push into the northern forecast area near the end of the 24
hour TAF period. Showers and associated restrictions will be
possible after 18Z Tuesday but confidence is low at this point.
EXTENDED AVIATION OUTLOOK...Chance of rain with CIG/VSBY
restrictions Wednesday through Thursday night as a front
approaches.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
Area Forecast Discussion
National Weather Service Dodge City KS
758 PM CST Mon Nov 6 2017
.UPDATE...
Issued at 757 PM CST Mon Nov 6 2017
Stratus dissolving rather quickly this evening. Lowered sky grids
to 50% through midnight. Stratus trends tonight into Tuesday are
uncertain, with competing forces from dry advection from the NE
and upslope flow. If stratus fails to redevelop soon, low
temperatures Tuesday will need to be lowered to the cold
MET/MAV guidance (mid 20s).
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 343 PM CST Mon Nov 6 2017
Water vapor loop and RAP analysis this afternoon showed a formidable
shortwave trough along the northern branch of the upper level jet.
This was diving southeast into southwestern Wyoming during the
afternoon hours, with a few echoes showing up on radar mosaic across
southeastern Wyoming. Response at the surface was becoming more
noticeable as lowering pressure across southeastern CO with a 1007mb
surface low centered from Trinidad, CO to east of Las Vegas, NM.
Another surface weakness was developing across South Dakota. The
South Dakota weakness will become squashed by much stronger
anticyclogenesis at the surface across Montana tonight. This large
surface high will expand southeastward rapidly tonight, which will
actually help push drier surface air down into Nebraska and Kansas.
The low level dry advection is expected to erode the lingering
stratus on the east side overnight. Low level cyclogenesis tonight
will be fairly weak, but still perhaps sufficient enough for
development of patchy drizzle or even freezing drizzle across far
west-central KS in the 06-12z time frame tonight. Several of the
mesoscale models indicate this possibility, showing blotchy 0.01
inch QPF during this time frame along the CO-KS border north into
northeastern CO.
The upper level disturbance will continue to push southeast tonight,
but stretching out as it enters the Rockies. This is now expected to
limit 700mb frontogenesis tomorrow and tomorrow night to mainly
eastern CO and adjacent far southwestern KS. POPs have been scaled
back some across southwest KS, mainly northeast of a Garden-Dodge-
Ashland line. Northeast of this line, there is an increasing
likelihood that no precipitation will fall at all with this system.
It does still appear, however, that around an inch of snow will fall
in the far southwest, particularly Elkhart area. Most areas between
Elkhart to Garden-Dodge will only see a few tenths of an inch of
snow, if anything at all, given 1) strength of the surface high
moving and associated low level dry air and 2) the track of the
500mb vorticity center tracking from western Colorado to the Texas
Panhandle, keeping the best overall lift and attendant 700mb
frontogenesis to the south of the southwest KS region.
.LONG TERM...(Tuesday night through Monday)
Issued at 119 PM CST Mon Nov 6 2017
A dry period is expected early in the period as medium range models
indicate an upper level shortwave trough transitions southeast out
of the Central Plains into the lower Mississippi River Valley,
giving way to weak upper level ridging across the Intermountain
West and a northwest flow aloft across the Western High Plains.
With a significantly drier air mass settled across the region,
any lingering precip chances due to the exiting upper level
shortwave will quickly dissipate by Wednesday afternoon. The dry
period will continue through Friday as the flow aloft becomes more
zonal. Surface high pressure will shift eastward across the Central
Plains Wednesday, returning a southerly flow to western Kansas.
This will begin to slowly erode the colder airmass across the high
plains with H85 temperatures climbing above 0C. Highs in the 40s(F)
can be expected Wednesday afternoon. The warming trend will continue
through the end of the week with highs pushing up into the 50s(F)
Thursday with a few 60s(F) possible Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 500 PM CST Mon Nov 6 2017
MVFR stratus cigs persist as of 23z, with a few breaks here and
there. Complicated TAF package with regards to stratus trends, as
strong surface high pressure builds into SW KS from the north.
Expecting MVFR stratus to persist at the airports much of the
night at all airports. A cold front with a reinforcing surge of
cold/dry surface air will arrive around 12z Tue, increasing
NE surface winds to 15-25 kts. Models show the stratus cigs slowly
lifting into low end VFR at DDC/LBL daylight Tuesday, in response
to dry advection in the boundary layer. MVFR stratus is most
likely to hold at GCK, where VCSH was included after 18z Tuesday.
Slim chance of drizzle or light snow at GCK after 18z, but kept
out of the 00z TAFs with low confidence. Deeper in the incoming
dry air mass, stratus may break completely at HYS after 18z
Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 40 27 46 / 0 10 20 10
GCK 31 36 27 46 / 10 20 30 10
EHA 31 37 28 46 / 10 20 50 10
LBL 32 39 27 45 / 0 20 40 20
HYS 30 40 26 47 / 10 10 10 10
P28 35 45 30 47 / 0 10 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Turner
SHORT TERM...Umscheid
LONG TERM...JJohnson
AVIATION...Turner
Area Forecast Discussion
National Weather Service Goodland KS
432 PM MST Mon Nov 6 2017
.SHORT TERM...(This evening through Tuesday)
Issued at 245 PM MST Mon Nov 6 2017
Main forecast issue will be an extended period of light freezing
precipitation later on tonight into tomorrow morning. With
stronger upslope today, clouds have held on longer with much
cooler temperatures expected. Current satellite shows a rather dry
air mass, above the saturated boundary layer moisture, over and
upstream of our area.
Fog just burned off in eastern Colorado. High resolution guidance,
especially the Hrrr, is doing very well with current temperature
and boundary layer moisture fields. The Hrrr caught the fog very
well followed by the Rap. Freezing fog will redevelop roughly
along and west of the Colorado border during the evening in
advance of the develop precipitation does not look to start in the
northern of our area until around midnight.
With the westerly flow aloft, the expected deep dry air mass
mentioned above will be slow to saturate. Nam forecast soundings
were catching this reality of the thermal and moisture fields the
best. So for most of the period from 06z tonight through the
morning hours on Tuesday, the Nam is showing that there is no ice
in the column, no elevated warm layer, and the sounding below 700
mb between -6 to -10C.
So it looks like freezing drizzle and rain is expected from later
this evening through the morning hours tomorrow. Precipitation
amounts will be light, less than a tenth of an inch at this time,
but most of that will be realized as ice. So as a result have
issued a Winter Weather Advisory from 11 pm mountain tonight to
noon on Tuesday for the western half of the area. It looks like
the soundings get saturated deep enough to have ice in the column
from late in the morning through the afternoon. So on top of any
accumulating ice, will be a thin layer of snow. Temperatures will
be going nowhere tomorrow and should not get out of the 30s.
.LONG TERM...(Tuesday night through Monday)
Issued at 410 PM MST Mon Nov 6 2017
H5 trough will move out of the region on Wednesday with a weakening
ridge moving eastward out of the Great Basin. This will flatten as
we head into Thursday, eventually becoming zonal going into Friday.
A chance of snow or a freezing drizzle/snow mix will persist into
the early morning hours on Wednesday, ending around sunrise. This
will mainly be observed west of the Kansas/Colorado border and south
of Interstate 70. Dry weather will prevail Thursday through Sunday
with temperatures gradually warming each day.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 432 PM MST Mon Nov 6 2017
Light wintry precipitation may impact both terminals late tonight
through Tuesday morning. Lowest cigs and best chance for any
precipitation will be at KGLD where a period of freezing drizzle
is expected transitioning to light snow and decreasing in
coverage around 15Z. I have less confidence in these impacts at
KMCK so I left FZDZ mention out during this update. I also can`t
rule out brief drops to IFR cigs or vis, but trend for prevailing
conditions is away from this and I kept CIGs about 1000ft AGL. VFR
conditions are expected by the afternoon, however there is still
a chance light snow could continue to impact either terminal into
the afternoon hours Tuesday (though chances/confidence wasn`t
high enough to keep this in the TAFs).
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Winter Weather Advisory from 11 PM MST /midnight CST/ this
evening to noon MST /1 PM CST/ Tuesday for KSZ001-002-013-
014-027-028-041-042.
CO...Winter Weather Advisory from 11 PM this evening to noon MST
Tuesday for COZ090>092.
NE...Winter Weather Advisory from 11 PM MST /midnight CST/ this
evening to noon MST /1 PM CST/ Tuesday for NEZ079-080.
&&
$$
SHORT TERM...BULLER
LONG TERM...TL
AVIATION...DR
Area Forecast Discussion
National Weather Service Green Bay WI
518 PM CST Mon Nov 6 2017
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Tuesday
Issued at 208 PM CST Mon Nov 6 2017
The latest RAP analysis and satellite/radar imagery show high
pressure stretching from the northern Rockies into the western
Great Lakes early this afternoon. A weak area of low pressure is
moving east over western South Dakota, and is producing snow over
eastern S.D. into southwestern Minnesota. Mid-level clouds are
increasing across the southern two-thirds of Wisconsin, while last
nights low clouds have retreated to the north shore of the Upper
Peninsula. As this weak system moves across the region tonight,
snow chances are the main forecast concern.
Tonight...A sheared short-wave will move across the region, but
weak lift and a lack of deep saturation will limit precipitation
development. Progged soundings do moisten the sub-cloud layer
below 5-6 kft, so think that some snowflakes could reach the
ground though, mainly in the late evening to mid-overnight hours.
Therefore, kept a chance of flurries over mainly north central
WI, and a small chance of lake effect snow showers over northern
Vilas county (winds are too westerly for any significant
accumulations). Low temperatures should range from around 20 in
north central WI to around 30 near Lake Michigan.
Tuesday...High pressure will reassert itself as the shortwave
departs to the east during the morning. As a result, clearing
will progress from northwest to southeast through early afternoon.
Despite abundant afternoon sunshine, temperatures will remain
chilly, ranging from the upper 20s northwest to the upper 30s
southeast.
.LONG TERM...Tuesday Night Through Monday
Issued at 208 PM CST Mon Nov 6 2017
Well below normal temperatures will continue on towards the
weekend. A mid level trough will accompany another cold front
Wednesday night into Thursday, for a chance to see some snowfall
in northern Wisconsin. Some lake enhancement from Lake Superior will
be possible for the far north affecting primarily Vilas and
northern Forest counties. Northwesterly flow will continue
through Thursday into Friday with the rest of the area remaining
dry but much colder than normal. Any lingering snow showers will
come to an end on Friday as the winds shift back towards the
south.
Expect a warming trend towards the end of the week and into the
weekend, ahead of the next upper level trough. Active weather is
expected Saturday into Sunday as high temperatures skirt around
the freezing point. Mostly snow is expected in northern Wisconsin,
with a chance to see some rain further south during the afternoon.
Any precipitation that sticks around towards the end of the day on
Sunday will return to snow.
Highs will start in the 30s on Wednesday, before dipping into the
20s and upper teens on Thursday. A return to the 30s is in store
over the course of the weekend.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 515 PM CST Mon Nov 6 2017
Quiet weather and generally good flight conditions are
anticipated during the next 24 hours, with just middle and high
clouds passing through the region. Some Sc off Lake Superior may
briefly work into north-central Wisconsin late tonight as low-
level flow turns more northwesterly.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Uhlmann
AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Indianapolis IN
950 PM EST Mon Nov 6 2017
.UPDATE...
The NEAR TERM and Aviation Sections has been updated below.
&&
.SYNOPSIS...
Issued at 254 PM EST Mon Nov 6 2017
A couple of waves will move along a front in the Tennessee Valley,
bringing chances for rain to central Indiana tonight and Tuesday.
High pressure will then provide dry weather through Friday. Another
low pressure system will bring more rain chances for the weekend.
Temperatures will remain below average.
&&
.NEAR TERM /Overnight/...
Issued at 950 PM EST Mon Nov 6 2017
Surface analysis late this evening shows weak low pressure in
place over Arkansas. GOES16 shows clouds streaming east across
Indiana within the flow aloft. Water Vapor shows a upper
disturbance over middle Mississippi River Valley streaming
northeast. Temps across the area were mainly in the 40s.
Models suggest the upper wave to the southwest will continue to
stream east and provide lift across southern Indiana as a surface
low develops and strengths...passing along the Ohio River. HRRR
suggests precipitation development overnight...mainly across the
southern parts of Central Indiana. Thus have fine tuned pops a
bit...focusing best pops mainly across the southern parts of
Central Indiana.
Given the expected clouds and rain...trended overnight lows warmer
than the forecast builder blend.
&&
.SHORT TERM.../Tuesday through Thursday/
Issued at 254 PM EST Mon Nov 6 2017
Models are close enough that the model blend initialization
was accepted for most items.
Decent forcing will be ongoing across the far southeast with the
start of the Tuesday period so will go with likely PoPs there with
chance or lower PoPs farther northwest. These will diminish during
the morning as the forcing exits. Will go dry during the afternoon.
Another system to the south will bring some PoPs to the far
southwest Tuesday evening, but forcing is much weaker with this
system. Will only go slight chance PoPs to low end chance PoPs there
during the evening.
Afterward high pressure will build in and keep conditions dry
Wednesday and Wednesday night. A cold front will move in on
Thursday, but with no moisture to work with, dry conditions should
continue.
Model blend temperatures look reasonable.
&&
.LONG TERM /Thursday Night through Monday/...
Issued at 227 PM EST Mon Nov 6 2017
A progressive and somewhat zonal upper flow will occur over the
long term period. High pressure over the upper midwest Thursday
night and early Friday will track east across the Great lakes
brining cool and dry weather through early Saturday. A frontal
system and low pressure will give us a chance of showers late
Saturday into Sunday. The Canadian and GFS are a little faster
with the best chances of rain being Saturday night and the Euro
being a little slower with the best chances of rain occurring
Sunday and early Sunday evening. Will go with a blend for now
which is close to Superblend POPS.
After Sunday it will be dry and cool as high pressure builds into
the upper midwest and eventually our region.
Concerning temperatures went near to slightly above...close to a
Superblend MEX MOS blend.
&&
.AVIATION /Discussion for the 070300 IND Taf Update/...
VFR conditions are expected to continue the next several hours.
Only minor changes to the ongoing TAF as MVFR Cigs should hold off
until after 15Z.
Previous Discussion Below
/Discussion for the 070000Z Tafs/...
Issued at 705 PM EST Mon Nov 6 2017
VFR Conditions are expected to deteriorate to MVFR/IFR CIGS
overnight.
A quick moving short wave was found across Southern Illinois and
will push across the Ohio Valley tonight. Radar shows areas of
rain over Western Kentucky and Illinois developing...pushing east
within the flow. The bulk of this precip will remain close to the
Ohio River, however best chances for impacts will be at the BMG
TAF site...along with IFR conditions on Tuesday Morning as the
surface low moves east across Kentucky.
HUF and IND sites will mainly fall to MVFR conditions as the
surface low passes to the south. Improvement to VFR is expected at
all TAF sites by 21Z Wednesday as High pressure arrives from the
northwest.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....JH
AVIATION...JP
Area Forecast Discussion
National Weather Service Jackson MS
952 PM CST Mon Nov 6 2017
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Latest surface analysis indicates a stationary frontal boundary
located over the extreme northwestern area of the CWA. Zonal flow
aloft is allowing for only a slow southward progression of the
front into the region, but nevertheless it is expected to continue
its crawl through the area overnight and into tomorrow. Increasing
cloudiness can be expected throughout the region tonight along
with a slight chance of showers across the northern counties.
Patchy areas of dense fog are possible after midnight across the
southern counties, extending a bit farther northeast toward
Meridian in eastern locations. Low temps will be in the mid to
upper 60s across the CWA, with the chance for temps to cool a bit
more in northwestern locations as cooler air filters in behind the
front. /TH/
Prior discussion below:
Tonight through Tuesday...
Latest Rap and Satellite imagery showed flat ridging through the
atmosphere. A stationary cold front was positioned just north of
the forecast area where there was a big difference in temps.
Readings south of the boundary were in the 70s and 80s to the
north 50s and 60s. Area radars were picking up some showers north
of the forecast area.
For tonight latest CAM guidance shows some showers developing over
our northern counties overnight. There may be some limited potential
of some elevated convective potential. Guidance is also looking at
some patch fog to develop generally along and south of interstate
20. It will be another mild night with above normal lows in the
middle to upper 60s. Could see some near record high minimum temps
overnight.
For Tuesday expect the chances of rain to spread south to around the
interstate 20 corridor as the cold front makes it way slowly to the
south. There should be enough instability for some thunderstorms
during the afternoon. At this time not seeing any strong
thunderstorm potential. So as far as the short term is concern will
keep the HWO clear at this time. Highs on Tuesday will range from
the Lower 70s north to the lower 80s south./17/
Tuesday night through Sunday...
Zonal flow will continue across the region and a cold front will
slowly sag south across the area through Wednesday. This will
continue to keep chances for rain and some storms in the forecast
through Wednesday, with the highest chances of rain across central
portions of the forecast area on Wednesday. Rainfall amounts of
around 1-2 inches will be prevalent areawide, but it appears the
greatest QPF amounts will be along the I-20 corridor. Given the
relative dry nature of our weather pattern prior to this, flooding
should not be an issue. Most of this rain should also not be very
convective, which will also limit the potential for heavy rain and
flooding. However, this rainfall should be much appreciated.
By Wednesday night into early Thursday, the front will finally have
a push to clear the region as a shortwave trough will push through.
Rain will clear the southeast during the early portions of Thursday
and a cooler, drier airmass will filter into the region.
Temperatures through the end of the week into the weekend will feel
a bit more like fall, with highs in the 60s and lows in 40s. By late
in the weekend, another front will move through the region and bring
another round of rain and storms with it. Behind this, shortwave
ridging will once again move in. /28/
&&
.AVIATION...
00Z TAF discussion:
VFR conditions early in the period will become MVFR by midnight
and eventually IFR thereafter as low clouds and fog develop across
the region. These conditions will linger through mid morning
Tuesday followed by a slow rise in ceilings to MVFR. Showers and
thunderstorms will develop in the vicinity of GLH, GWO, and GTR
after midnight as a weak cold front moves into the area. The front
will pass through these locations between 07/14Z and 07/18Z, but
low flight categories will continue through the end of the period./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 68 77 59 63 / 1 21 38 85
Meridian 65 79 60 65 / 1 21 29 84
Vicksburg 67 76 57 60 / 1 25 43 85
Hattiesburg 66 80 64 71 / 3 8 12 64
Natchez 67 77 59 63 / 1 13 40 73
Greenville 64 68 52 56 / 4 38 56 85
Greenwood 67 69 54 58 / 5 40 54 85
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
Area Forecast Discussion
National Weather Service Melbourne FL
845 PM EST Mon Nov 6 2017
.UPDATE...
...Widespread low clouds with some areas of dense fog overnight...
Tonight...A high pressure ridge over the northeast Gulf of Mexico
and a weak inverted trough to our east will continue to provide
northerly low level winds. This flow has certainly not been tapping
any drier air, as afternoon dew points were in the mid-upper 60s,
and even in the lower 70s along the coast. High pressure aloft
should result in mostly clear skies, except along the Treasure Coast
where some cloudiness and isolated showers will move down the Gulf
Stream and push ashore. After 2 mornings with low stratus and fog,
the pattern will remain favorable for another round to develop after
midnight and become widespread.
The HRRR model has been showing fog working down from the north with
coverage similar to this morning, northward from about Okeechobee to
Vero Beach. Cape Canaveral profilers show about 15 knot northerly
winds in the boundary layer, so the lowest visibility should again
be near/west of Interstate 4. Expect local/areas of dense fog to
occur there in the pre-dawn hours.
Don`t see anything substantial to change in the current forecast
package.
&&
.AVIATION...
00z TAFs were essentially unchanged from the previous set which
somewhat mirrored what occurred early this morning. Areas of LIFR
are expected again in the pre-dawn hours, especially ISM-MCO-SFB-LEE.
Northerly winds may keep the low levels mixed enough to limit
duration/extent of very low ceilings at the coastal terminals.
&&
.MARINE...
Tonight-Tuesday...Buoy 41009 has been reporting north winds around
12 knots most of the evening with seas close to 4 feet. Weak
inverted trough is forecast to persist in the vicinity of the west
wall of the Gulf Stream into Tue morning. This should maintain
rather steady state winds and seas 3-4 feet. Widely scattered
showers have been moving down the Gulf Stream and don`t anticipate
any changes in that through Tue morning.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Lascody/Sedlock
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
601 PM CST Mon Nov 6 2017
.SHORT TERM...(This evening through Tuesday)
Issued at 259 PM CST Mon Nov 6 2017
Very dry atmosphere in the lowest 5k has kept most of the
measurable precipitation in far southwest Minnesota today. Area
web cams have noted that portions of southwest Minnesota have
seen a half inch to locally one or two inches of snow based on
these web cams. Only favorable areas of receiving any measurable
snowfall will occur along the Minnesota River Valley, south to the
Iowa border through the early evening as this system continues to
weaken. Any farther to the north, the drier air mass will keep
most of the area precipitation free, with only a few flurries
possible.
Forecast concerns tonight relate to the current run of the HRRR,
ESRL HRRR, and RAP which all noted some measurable snow this evening
in west central Minnesota where another weak disturbance moves
across the Dakotas. Although this is noted early this afternoon on
regional satellite imagery in southern Montana, there remains no
significant trigger for development of bands of light snow, only a
few flurries at best in Minnesota. Later forecasters can see how
well organized this system becomes this evening as it moves across
the Dakotas. Otherwise, a slow decrease in the cloud cover is
expected tonight, but temperatures will fall into the teens in
central Minnesota, to the 20s elsewhere.
.LONG TERM...(Tuesday night through Monday)
Issued at 259 PM CST Mon Nov 6 2017
Precip wise, the weather for the next week looks fairly quiet, with
the only meaningful chance for precip coming Saturday with what is
increasingly looking like a minor system at best. For temperatures,
it will be cold this week, especially Thursday, but a warmup back to
and even above normal still looks on track for next week.
Looking at the large scale, the dominate weather feature for this
week will be an anomalously deep h5 low dropping down around Hudson
Bay Thursday/Friday, which will bring us a hit of modified arctic
air to end the week. For the weekend, we`ll see the flow flatten
out, while next week the flow will become quite amplified in the
Pacific, with a ridge building into the Bering Sea and a trough
digging across the eastern Pac. This will send a ridge up our
direction and finally give us a reprieve from this prolonged stretch
of colder than normal weather that set in back on the 27th of
October.
Though cold, we`ll actually start out Wednesday in a warm sector
ahead of a cold front passing through. GFS is quite a bit faster
than the ECMWF and NAM with this FROPA and looks too cold for highs
Wednesday, so favored the forecast toward the warmer ECMWF/NAM, with
a decent shot at hitting 40 up to a Morris/St. Cloud/Chippewa Falls
line. Moisture with the front is lacking and forcing with it`s
parent upper wave in terms of PVA will be going from NW MN over to
northern lower MI, so we`ll be getting a glancing blow from this,
with only small chance for a quick hit of light snow behind the
front (but ahead of the shortwave) north of I-94. Behind the front,
h85 temps will be 10 to 20 degrees C below normal for Thursday, so
although a good 20ish degrees below normal, current forecast highs
in the upper teens to mid 20s for Thursday look good.
Going into Friday, the question becomes how quickly does the warm
air return as we get on to the back side of the Canadian high. GFS,
which looks too quick with bringing the front in Wednesday also
looks too quick with bringing the warm air back on Friday, so went
closer to the ECMWF for highs on Friday, which are only a couple of
degrees warmer than what is expected for Thursday. The one thing
that may need to be changed in the coming days for Friday is to
boost winds some as the pressure gradient gets cranking between the
departing 1040mb high over the Great Lakes and the 1005mb low
pressure trough moving across the Dakotas. Forecast soundings off
the 06.12 GFS in western MN Friday show top end potential for
sustained southeast winds in the 25-30mph with gusts to around 40
mph.
For the weekend the flow will become more zonal as the Hudson
Bay low lifts off toward Greenland. There will be at least one wave
heading across the upper MS Valley this weekend, but models still
disagree a bit on details. The key differences deal with a wave that
will come onshore in the Pac NW on Friday. This wave will be
splitting apart as it comes across the Rockies. The ECMWF keeps two
distinct waves with this system, one going across southern Canada
Friday night/Saturday, with a second southern stream wave tearing
off and going from CO Saturday into the Ohio Valley Sunday. The
GFS/GEM are not as aggressive with splitting this wave apart on
Friday and instead bring a single wave across upper MS Valley
Saturday that deepens to our east on Sunday. The net result is the
ECMWF shows nothing happening, while the GFS/GEM continue to break
out some light precipitation ahead of the wave Saturday, especially
along/east of I-35, with the GFS warm enough to have the majority of
that precip come as rain. So even if we do end up getting something,
the probability of a high impact winter event looks pretty low.
Sunday, we`ll see a surface ridge move through, which will help hold
our temperatures in the 30s, but by Monday, we`ll see ridging
building up out of the southern Plains which will send our highs
back up into the 40s, with some 50s not out of the question as we go
through the course of next week. In fact, when you look at the
frequency of 50+ highs in the Twin Cities for the month of November,
you have to go back to 1997 to find a November that produced zero
highs at or above 50, with the fewest number of 50+ highs since then
at 4, so we likely still have a couple of 50 degree highs left in us
before we go all out winter mode.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 601 PM CST Mon Nov 6 2017
VFR conditions expected, except across southwest MN where MVFR
cigs should develop a bit later this evening. A few flurries are
also possible there through the evening. Drier air will work in
from the north Tuesday with clearing skies expected mid morning
onward.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
Wed...VFR. Wind SW 5-10 kts, becoming northwest.
Thu...VFR. Wind NW 10-15 kts.
Fri...VFR. Wind SE 10-15 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...JLT
LONG TERM...MPG
AVIATION...BORGHOFF
Area Forecast Discussion
National Weather Service Marquette MI
715 PM EST Mon Nov 6 2017
.SHORT TERM...(This evening through Tuesday)
Issued at 258 PM EST MON NOV 6 2017
Water vapor imagery and RAP analysis show broad troffing from the nw
CONUS to the Upper Great Lakes with a shortwave swinging across
Manitoba. At the sfc, high pres is ridging from the Dakotas to Lower
MI. Position of the high pres ridge combined with approaching
shortwave over Manitoba has resulted in winds backing w to wsw
today, causing light LES, mostly just flurries, to shift n. This has
also allowed skies to clear out in areas where flow off Lake
Superior has been lost.
Short term part of the fcst will be affected by shortwave currently
over Manitoba. This wave will swing across Lake Superior tonight,
providing a brief period of weak synoptic forcing, mainly during the
evening. As the wave passes, fcst soundings show a very brief
lifting of the inversion which is initially based at 4-5kft. With
Lake Superior sfc water temps roughly around 7C, air mass will be
plenty cold enough to support LES as 850mb temps of -8 to
-10C to start the evening fall to -12 to -13C by morning before
moderating back to -8 to -10C by late Tue aftn. However, as has been
the case since last evening, fcst soundings continue to show a well-
mixed boundary layer (inverted-V profile) which is a negative for
LES. The negative impact of the dry air/well-mixed boundary layer
was evident this morning as LES remained light even with the 850mb
temps of -10/-11C. So, while passing shortwave will give LES a bit
of a boost as will the colder air arriving overnight, LES probably
won`t produce more than an inch or two of accumulation where -shsn
are most persistent. Longer fetch will provide better lake
moistening of the boundary layer into the ne fcst area, so heavier
shsn will affect that area. In addition, subtle wind shift as sfc
trof drops across Lake Superior will lead to a band of at least mdt
shsn moving onshore over the ne fcst area late tonight/early Tue
morning, and that may end up producing the bulk of the snow
accumulation. Increasingly anticyclonic low-level flow and lowering
inversion will cause LES to diminish from w to e during Tue. Backing
winds ahead of the next approaching low pres trof will also shift
the lingering LES to the n with time and will allow for increasing
sunshine from sw to ne. LES should end over the w in the early aftn
and e of Grand Marais by evening.
.LONG TERM...(Tuesday night through Monday)
Issued at 316 PM EST MON NOV 6 2017
Overall, confidence has increased in the timing and magnitude of the
first, early taste of winter across the Upper Great Lakes. This
colder, arctic air is expected to impact the region Thursday through
Friday and will bring moderate to heavy lake effect snow primarily
across the northwest wind snow belts. Temperatures will warm back up
towards seasonal this weekend into early next week, but
precipitation chances may linger through the weekend.
Tuesday night and Wednesday: Expect dry conditions to start off with
increasing cloud cover as surface ridging briefly clips the region
ahead of an advancing weak surface trough from the north. With
colder air beginning to filter south along and behind this surface
trough, expect 850mb temperatures to cool down enough for lake
effect snow showers to begin in the west wind snow belts towards the
end of the day on Wednesday.
Wednesday night through Friday: Quasi-zonal flow is progged to
become highly amplified across the Upper Great Lakes as a potent
shortwave digs south from Canada. Due to the strong cold air
advection along and behind this shortwave, expect moderate to heavy
lake effect snow to develop initially in the northwest wind snow
belts Wednesday night into Thursday. Further inland from Lake
Superior, as the main shortwave digs across Upper Michigan snow will
also be possible down to the Wisconsin border. By Thursday
afternoon, snow across the interior central will diminish while lake
effect snow continues as the main trough axis shifts east of the
region. With 850mb temperatures progged to drop to around -20C at
times, ample lake-induced CAPE and inversion heights approaching 10k
feet will be more than sufficient to support a convective boundary
layer. With the above mentioned cold air advection, forecast
soundings also show ample lift and cloud depth through the DGZ,
which will allow for efficient ice production, and thus higher
snowfall rates. Therefore, have increased QPF and kept the trend of
increasing SLRs, and thus accumulating snow, in the northwest wind
snow belts to account for this Wednesday night through Thursday.
Along with the accumulating lake effect snow gusty northerly winds
will spread across the area, especially near the shore of Lake
superior. This will likely result in reduced visibilities as SLRs
should become high enough to transition over to fluffier snow. Late
on Thursday through Friday, expect the lake effect to diminish from
west to east across Upper Michigan as a strong arctic high pressure
system slides across the region.
Temperatures during this time period will definitely provide the
first taste of winter for the region. The strongest cold air
advection is expected to arrive during the day and overnight hours
on Thursday. Therefore, expect temperatures to fall through the day
on Thursday across much of the area. In fact, by the afternoon hours
temperatures may only top out in the teens across portions of the
west and central. Gusty northwest winds will make it feel even colder
out, with wind chill temperatures only approaching the single digits
to teens in some locations. Thursday night into Friday morning,
overnight lows are expected to drop into the single digits across
the interior west and central, and into the teens elsewhere. The
combination of the cold air mass and lingering breezy winds will
make conditions feel around or just below zero across the area
during the overnight hours.
The up and coming weekend through early next week: An active pattern
is progged to develop this weekend into early next week, fostering
additional widespread and lake effect precipitation chances. The
above mentioned surface ridge will quickly slide east of the region
and we will get back under a quick shot of return flow ahead of an
approaching shortwave for Saturday. The medium-range models disagree
on the strength of this wave, but with the main trough axis tracking
across the region with broad warm air advection, this should foster
widespread light snow on Saturday. As the main trough axis pushes
east across Upper Michigan, another round of cold air advection will
push southeast across Upper Great Lakes Saturday night into Sunday.
This will allow any lingering widespread snow to transition to lake
effect snow in the northwest wind snow belts by Sunday. Early next
week, ridging is progged to build across the region and should favor
a warm up.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 659 PM EST MON NOV 6 2017
VFR conditions at the TAF sites will give way to MVFR conditions
in lake effect -shsn at KCMX and KIWD later tonight as a
disturbance and associated sfc trof pass across the area and winds
veer more to the nw across Lake Superior. Downslope nature of the
wind at KSAW should maintain VFR conditions at that terminal.
Westerly winds and increased mixing across the lake will lead to
gusty winds above 20 knots at times at KCMX. Expect improvement to
VFR at KIWD and KIWD by Tue afternoon as winds back sw and push
lake effect bands north of these sites.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 258 PM EST MON NOV 6 2017
Low pres trof will drop se across Lake Superior tonight. Ahead of
the trof, westerly winds of 20-30kt will prevail with perhaps a few
gale force gusts. In the wake of the trof, winds will diminish from
w to e late tonight/Tue morning, leading to a short period of winds
under 20kt. Winds will then quickly ramp up again from w to e Tue
aftn/evening ahead of the next approaching trof. There should be a
period of gales over portions of w and central Lake Superior Tue
night. Winds will diminish a bit Wed. In the wake of the trof, a
very cold air mass for this time of year may lead to gales on Thu,
especially over the e half of Lake Superior. Winds will diminish
from w to e Thu night/Fri, down to under 20kt for a time as a high
pres passes. Winds will then ramp up again into Sat ahead of the
next approaching low pres trof.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Watch from Tuesday evening through Wednesday morning for
LSZ242>244-263-264.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...Ritzman
AVIATION...Voss
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Omaha/Valley NE
528 PM CST Mon Nov 6 2017
.SHORT TERM...(Tonight through Thursday)
Issued at 248 PM CST Mon Nov 6 2017
WV imagery this afternoon showing that the large scale pattern
has amplified a bit since yesterday in part to a positive tilt
trof currently extending from the Pac NW into central Canada. At
the surface...a large area of high pressure was in control over
the majority of the eastern half of the CONUS.
The going forecast is in pretty good shape...only minor tweaks
needed. The chance for light snow continues over portions of the
northern CWA tonight. Lift will increase withe approach of an
elongated vorticity channel dropping out of the northern Plains.
Upper level Qvec convg...per both the NAM12/GFS20...suggests lift
via DPVA will be able to overcome the deep layer cold air
advection settling in. At any rate...the potential for light snow
accumulation will be focused over northern NE as well as extreme
southern SD. All told...the HRRR and RAP12 advertise accumulations
by events end Tuesday morning up to about half inch.
Otherwise...Dry and cold Tuesday through Thursday with highs
generally in the mid 30s-low 40s and lows in the low/mid 20s.
.LONG TERM...(Thursday night through Monday)
Issued at 248 PM CST Mon Nov 6 2017
No major changes planned in the extended periods. Dry and cold will
be the rule heading into next weekend with highs in the mid 40d.
Through next weekend both MAV/ECM MOS meteograms suggest a modest
warming trend with highs topping out in the low 50s. Precip
chances continue then Friday night/Saturday morning associated
with a Pac NW shortwave trof crossing into the central Plains. As
of now...dominate precip type is progged to be rain.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 527 PM CST Mon Nov 6 2017
At KOMA and KLNK, VFR conditions are expected through the TAF
cycle. At KOFK, light snow may affect the site later tonight into
Tuesday morning. Winds will remain light at all sites, with speeds
mainly around 6kt or less and direction shifting from
east/northeast to north and northwest by the end of the TAF cycle.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...Mayes
Area Forecast Discussion
National Weather Service Nashville TN
725 PM CST Mon Nov 6 2017
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Latest radar imagery shows widespread light to moderate rain with
a few embedded thunderstorms continues to spread eastward across
Middle Tennessee, now entering the Upper Cumberland. Regional
radar imagery shows activity still extends westward into Arkansas,
so off and on rain with some lightning and thunder will continue
through the night before ending from west to east after sunrise
Tuesday morning. Have raised pops this evening and tonight in
line with latest HRRR model runs. Surface observations show
frontal boundary has sagged southward to just south of the
Alabama border, with all of Middle Tennessee now in the stable
cool surface layer north of the front. Temperatures will therefore
remain steady or only drop slightly the rest of the night. OOZ
OHX sounding shows elevated instability up to 250 J/Kg is present
north of the front along with deep layer shear up to 55 knots, so
cannot rule out an isolated strong storm or two with small hail
overnight - mainly across southern counties closer to the surface
front.
&&
.AVIATION...
00Z TAF DISCUSSION.
A boundary is situated across Southern TN and a low will ride
along this boundary tonight and tomorrow. This will give the
possibility for thunderstorms tonight area wide...with a few
strong storms possible across the south. The main threat will be
hail and wind.
With the boundary in place all TAF sites will see mainly IFR
conditions. It might even be LIFR around 12Z and in and around
thunderstorms. Hopefully visibilities will improve after 18Z and
ceilings will improve to MVFR around 00Z Wednesday.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Shamburger
AVIATION........12
Area Forecast Discussion
National Weather Service Blacksburg VA
636 PM EST Mon Nov 6 2017
.SYNOPSIS...
A cold front will travel east across the Appalachians into tonight.
Behind the front, high pressure with much cooler air will then wedge
down east of the mountains tonight. A series of waves will then
ripple through the region and bring a good chance of rain to the
forecast for Tuesday and again on Wednesday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 635 PM EST Monday...Cold front roughly bisects the
forecast area at this hour, extending from Fredericksburg
southwestward into Amherst County on through the New River
Valley into the eastern TN Valley in VA/TN. Still somewhat
marginally unstable ahead of the front in the Piedmont to spark
some scattered moderate showers through mid-evening. More
significant change in sensible wx conditions awaits behind the
front, with cooler/drier air and post-frontal stratus now
beginning to plague much of the western Appalachians in WV and
VA, with lowering trend in ceilings taking place in the New
River Valley. Expect overall similar trends with
lowering/thickening clouds initially west of the Blue Ridge, but
later in the overnight in the Piedmont. May see some patchy fog
in the western mountains develop as well as brief period of NW
winds subside to calm, but winds likely stay up enough overnight
in the Piedmont to mitigate any fog development there.
Front more or less stalls near or just south of southwestern VA
overnight as we await the weak mid-level impulse and strong
burst of 925-700 mb warm advection now across western TN. 18z
NAM/GFS guidance has started to speed up timing of rain closer
to the pre-dawn hours. Will not make changes as yet, but it is
possible that upward alterations to PoPs/Wx may be needed later
this evening if trends continue.
Previous near-term discussion issued at 304 PM follows...
A cold front located in the mountains this afternoon will travel
southeast this evening into tonight as a wave of low pressure lifts
northeast into Tennessee by Tuesday morning. The combination of
mixing and downsloping winds has scour out the low clouds with the
lingering wedge east of the Appalachians. SPC Day One
convective outlook has back off of the marginal threat for
Virginia and trimmed back the general thunderstorms for the
western mountains. The best threat for any severe thunderstorms
will occur to our west from the Ozarks to parts of Tennessee and
Kentucky. For our area, the threat severe weather is minimal
with the weak thermodynamic parameters.
Used a blend of the HRRR and Conshort for pops allowing for
isolated to scattered convection this afternoon into this
evening, then a expect a break in the action early tonight as
high pressure over the upper midwest strongly wedges into the
region. Added some patchy fog tonight especially in the western
valleys. The wave moving out of the Mississippi valley will
approach from the west late tonight. This wave will run over the
top of the wedge and create enough lift to spread a chance of
rain back into the west late tonight into Tuesday morning.
Cooler air arrives with the wedge tonight. Low temperatures
tonight will range from the lower 40s in the north to the mid
50s along the southern Blue Ridge mountains.
The unsettled weather will continue into Tuesday as an initial upper
level shortwave generating strong isentropic lift moves through The
area. On Tuesday, PWAT values surge to 200% of normal and strong
lift over the low level wedge should generate some moderate rains.
Utilized WPCGUIDE for QPF with the heaviest noted across the
northwest on the GFS and ECMWF. With these QPF values for Tuesday,
any flooding issues would be minor. Because of the solid wedge in
place, the best chance for thunderstorms will be confined to the far
southwest/western portions of the forecast area where there is some
instability and a small probability of CAPES reaching 500 j/kg.
High temperatures on Tuesday will vary from the the mid 40s in the
north to around 60 degrees in the far west.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 304 PM EST Monday...
Frontal boundary draped across the Gulf Coast States to the NC/SC
coast will keep our weather on the wetter side this period as upper
flow remains parallel to the front with little movement expected.
Waves of low pressure will ride along the front and drive moisture
northward into the Virginias into Wednesday night. The wetter period
looks Tuesday evening, with a gradual shift southward in the precip
coverage over time as a northern stream wave drives southeast into
the Great Lakes by Thursday. Temperatures will remain on the cool
side thanks to an easterly flow, with highs Wednesday and Thursday
mainly in the 40s, with some 50s piedmont Thursday.
By Thursday night, northern stream front will be riding east of us
with clearing taking place as strong high pressure works into the
Western Ohio Valley. Should be chillier by Friday morning with lows
in the lower 30s with mid to upper 30s east.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 304 PM EDT Sunday...
Cool high pressure will work from the Great Lakes/Ohio Valley Friday
into the Northeast U.S. by Sunday. This will keep us dry and cooler
than normal for the Friday-Saturday time frame, but return moisture
ahead of the next front may bring a cold rain to us Sunday into
early Monday. The pattern actually favors freezing precipitation as
warmer air overrides the colder air but this far out will be having
mainly rain, at times mixed with snow in the mountains late at
night/early morning time frame. At the same time models show
differences on the strength on the high and next system, with the
GFS weaker. Another thought is November climatologically is not
favorable for much ice of any consequence for our area.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
As of 635 PM EST Monday...
Generally VFR (except MVFR for Lewisburg and Bluefield)
conditions as cold front makes eastward march across the Blue
Ridge. May see a few showers from these but unlikely to develop
to the point where they would cause significant restrictions.
Conditions then deteriorate around 03z, becoming quite messy
with poor flight conditions through the rest of the TAF period.
Look for a west to east lowering in ceilings with post-frontal
MVFR to LIFR stratus and associated MVFR to LIFR at times.
Confidence is moderate on at least MVFR to IFR ceilings, but is
lower on LIFR ceilings. May see periods of patchy mist or fog
set in after midnight mainly in the western mountains. Have poor
confidence on how low visibilities may get and when any fog may
lift as OVC skies opens questions on radiational cooling. Offered
a 2SM BR for Blacksburg, Lewisburg and Bluefield with this TAF.
Winds appear too strong in the Piedmont for any mist or fog.
After a brief period of NW winds 3-6 kts, expect a veer to
northeast/east 4-8 kts in the Piedmont, but trend variable west
of the Blue Ridge overnight.
We will then await the warm front now making its way across the
western TN Valley. 18z guidance brings 5-6 SM frontal rain into
the region between 10-18z, with P6SM- type showers thereafter. Expect
very limited change in ceilings overnight through Tuesday, with
IFR to MVFR being common. Southwesterly 35-kt low-level jet
overlying light east winds at surface may allow for occasional
low-level wind shears particularly in the mountains of NC and
far southwest VA but unlikely at any TAF.
Extended Discussion...
This entire system should move east and off the coast by
Wednesday. In general, first half of the week looks unsettled
with a high likelihood for sub VFR conditions followed by slow
improvement to VFR by Wednesday or Thursday pending just how
fast the boundary pushes to the south by midweek.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...KK
NEAR TERM...AL/KK
SHORT TERM...WP
LONG TERM...WP
AVIATION...AL/KK
Area Forecast Discussion
National Weather Service Shreveport LA
936 PM CST Mon Nov 6 2017
.UPDATE...
The cold front has pushed a bit farther southeastward than
initially forecasted, as it was located along a Hope AR to near
Vivian LA to north of Jacksonville TX line. The HRRR seems to
have an excellent handle on the cold frontal propagation and as
such, should reach Shreveport shortly before midnight tonight.
Have therefore adjusted the forecast to reflect this trend.
Furthermore, temperatures have fallen a bit faster post-frontal
across southeast OK and extreme northeast TX and southwest AR
thus, lowering the min temperatures several more degrees seems
justified /lower 50s northwest to middle to upper 60s south/. Also
tweaked the dewpoint temperatures and relative humidity values as
a result of the faster frontal propagation. Computer models
continue to hint at the potential for post-frontal light precip so
have held onto slight chance POPs mainly near and north of the
Interstate-20 corridor tonight. Had to insert light patchy fog
across southwest AR as a few 03Z metars are reporting this
occurrence, and also added a fog mention across deep east TX and
central LA overnight given low temperature-dewpoint spreads /and
several computer models hinting at this plausibility/.
&&
.PREV DISCUSSION... /issued 554 PM CST Mon Nov 6 2017/
AVIATION...
For the 07/00z TAFs, ceilings are expected to gradually
deteriorate into the MVFR range areawide by 07/06z. Flight
conditions will likely continue to fall into the IFR range at most
sites through the overnight hours. Some patchy drizzle is also
possible before sunrise. MVFR/IFR ceilings will persist for the
remainder of the period. Scattered showers are expected to develop
by late morning as a cold front begins to slowly move across the
area.
CN
PREV DISCUSSION... /issued 222 PM CST Mon Nov 6 2017/
DISCUSSION...
Another very warm November day across the entire Four State Region
today with Shreveport having already eclipsed yet another record
high with us sitting at 87 degrees as of this writing. Mid 80s
are common across all areas along and south of the I-20 Corridor
this afternoon with temperatures north of the corridor near 80 to
the middle 70s across the Middle Red River Valley of Southeast
Oklahoma.
This should be the last day of threatened record high temps
as a slow moving, yet potent, cold front will be working its way
into our region overnight from the north and west. This front has
finally begun moving very slowly south and east this afternoon and
as of 20z was located near a Mena, Ar. Idabel, Ok. Mineola, Tx.
line. Given the shallow nature of the cooler post frontal airmass,
the front has had a difficult time clearing the Ouachitas which
is often the case with these airmasses but the airmass should win
out overnight. The front should be near a Palestine, Tx.
Shreveport, La. to El Dorado, Ar. line by 12z Tue and through all
but our extreme southeast zones by 00z Wed. Cannot rule out some
spotty showers along the southeastward moving frontal boundary
overnight but the models have been overdoing our rain chances
last night and today so have lowered overnight pops to slight
chance variety across our northwest half late. Obviously a big
spread in overnight min temps tonight as well with lower 50s
possible across Northern McCurtain County to near 70 across our
southern most zones.
Kept some post frontal light rain chances going during the day
Tuesday across most of the region but the cooler temperatures will
filter into the region behind the cold front as we await the big
weather maker in the form of a shortwave trough moving into the
Southern Plains late Tue Night. Isentropic lift over top a much
cooler boundary layer Tue Night appears to be much weaker than
what the models showed this time yesterday so have shaved pops
slightly for Tue Night but regardless of when the precip begins,
Wed looks very wet as PVA will be very strong with the above
mentioned trough as it moves into the Mid Red River Valley. Could
easily see rainfall amounts of 1-3 inches when it`s all said and
done with the rain pulling out of our region late Wed Night/very
early Thu morning. Cannot rule out some elevated embedded thunder
with this widespread rainfall event but no severe weather is
expected
Northwest flow aloft follows the trough for the end of the work
week but ridging quickly moves east of our region Fri Night with
another much weaker trough moving across the plains and another
cold front swinging through our region late in the day Saturday or
Sat Night. Not much moisture return with this trough but the
models continue to spit out some moisture along the above
mentioned frontal boundary so kept this kind of wording for the
weekend as well.
Prelims to follow...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 65 75 55 55 / 20 30 50 80
MLU 67 77 56 56 / 10 30 50 80
DEQ 54 60 50 50 / 20 30 50 80
TXK 59 63 51 51 / 20 30 50 80
ELD 63 67 51 51 / 20 30 50 80
TYR 61 69 50 50 / 20 30 50 80
GGG 63 72 53 53 / 20 30 50 80
LFK 68 80 57 57 / 10 10 50 80
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
29/09/13
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Tuesday)
Issued at 401 PM CST Mon Nov 6 2017
The coverage and timing the front edge of the current stratus deck,
along with whether it will generate any drizzle tonight, is the
primary challenge for the tonight and tomorrow forecast period.
Broad zonal upper level flow was present across the central U.S.
this afternoon with a coupled jet streak feature noted over the area-
-bringing light snow to the Siouxland. At the surface, a large high
pressure ridge extended across the Northern Plains and was exerting
its influence across northeast Kansas in the form of a modest
northeasterly wind. This wind and associated weak near-surface CAA
kept temperatures 10-20 degrees below average for this time of year
despite ample sunshine over much of the area. However, flow at 925-
850mb had backed to the S/SE, allowing a higher theta-e plume/low
stratus clouds to begin working northwestward back across southern
portions of the forecast area. The leading edge of the stratus was
along a line from Newton to Lawrence at 21Z.
Leaned heavily on the NAM/RAP/HRRR for timing of this stratus
deck...which resulted in pushing the edge of the stratus further
westward with this update. Expect that the stratus will reach Topeka
around 00Z--with the edge of the clouds remaining just to the north
and west of the city. Low clouds look to linger through the
overnight areas east of the Flint Hills with moisture confined to
850mb and below. RAP BUFR soundings depict enough lift within this
layer to possibly generate light drizzle--primarily along and
southeast of I-35--though there is a chance that Topeka and Lawrence
will see some drizzle. Continued CAA ahead of the advancing high
pressure cell resulted in lowering max temps for tomorrow a few
degrees from the going forecast. Also kept overcast skies for a
longer period in the east per recent short-term guidance
solutions.
.LONG TERM...(Tuesday night through Monday)
Issued at 401 PM CST Mon Nov 6 2017
Elongated upper trough axis over the CO Rockies gradually drops
southeast towards the southern plains Tuesday evening through
Thursday. Much of the available qpf resides south and west of the
CWA as the weak frontal boundary passes through dry on Thursday.
Upper riding is temporary through Friday before the next progressive
shortwave trough impacts the Midwest late Friday evening into
Saturday. Extended guidance is more on track with the GFS, ECMWF,
and Canadian models than previous runs with the qpf amounts
increasing across the eastern half of the CWA. Precip type remains
as rain with the lack of a colder airmass behind the boundary.
Temperatures improve throughout the week into the lower to middle
50s from Friday onward.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 451 PM CST Mon Nov 6 2017
Forecast for lower cigs to move into TOP/FOE only adjusted a few
hours, as still anticipate stratus to advect in this evening.
Clouds remain through the overnight, should lift to MVFR then VFR
through the day Tuesday. May see drizzle near TOP/FOE but chances
too low to include this far out.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Skow
LONG TERM...Prieto
AVIATION...67