Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/20/19
Area Forecast Discussion
National Weather Service Amarillo TX
610 PM CDT Sat Oct 19 2019
.AVIATION...00Z TAFs...Pressure gradients will weaken slightly
heading into the evening and overnight hours, though there will be
a strong low level jet around 2k ft AGL out of the southwest at
around 40 to 45 kts. This will help create low level wind shear at
all terminals until the winds can become surface based around
20/16Z as a Arctic Front impacts KGUY, and a Pacific cold front
impacts KDHT and KAMA. Winds should remain elevated through the
end of the forecast period around 20 to 30 kts with higher gusts,
along with high clouds streaming into the area AOA 20k ft AGL.
Other than the winds, VFR conditions will prevail through the
forecast period.
Bieda
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 71 47 76 35 65 / 0 0 0 0 0
Beaver OK 73 46 75 36 65 / 0 0 0 5 0
Boise City OK 69 43 69 29 62 / 0 0 0 5 0
Borger TX 74 49 77 38 67 / 0 0 0 0 0
Boys Ranch TX 72 46 77 33 67 / 0 0 0 0 0
Canyon TX 72 47 75 35 66 / 0 0 0 0 0
Clarendon TX 73 48 80 39 67 / 0 0 0 0 0
Dalhart TX 71 43 74 30 65 / 0 0 0 5 0
Guymon OK 72 46 71 34 65 / 0 0 0 5 0
Hereford TX 71 47 75 33 67 / 0 0 0 0 0
Lipscomb TX 74 47 79 38 67 / 0 0 0 5 0
Pampa TX 71 48 77 35 65 / 0 0 0 0 0
Shamrock TX 75 47 82 41 68 / 0 0 0 5 0
Wellington TX 76 46 83 42 70 / 0 0 0 0 0
&&
.PREV DISCUSSION... /Issued 248 PM CDT Sat Oct 19 2019/
.SHORT TERM...Tonight and Sunday...
Main focus in short term revolves around critical fire weather
conditions on Sunday. See Fire Weather section below.
Clear sky and dry low levels in post-frontal environment will lead
to a cool night, with lows about 7 to 10 degrees below seasonal
norms. Light to moderate southerly winds expected tonight as
surface ridge departs to our southeast while pressures as next pre-
frontal trof deepens to our west.
Cold front moves into northwest and northern sections Sunday
morning. Mid-level cloud deck expected to also move in to northern
sections. Decreased insolation will hold max temperatures below 70
in the northwest and will also keep winds down somewhat during the
morning. Clouds expected to dissipate during the afternoon. Drier
air moves in from the west during the afternoon with west winds
suggesting passage of a Pacific cold front. Sunday highs expected
to be about 5 degrees below normal. No pops through Sunday.
Cockrell
LONG TERM...
Current water vapor analysis shows a closed low over Washington
State. The 15Z RAP shows the associated trough axis running down
through Oregon into northern California. Further model analysis is
depicting this low moving over the Inner Mountain West as an open
trough tonight and becoming a closed low in eastern Colorado by
Sunday morning. Sunday, this system will bring in an associated
cold front into the CWA, as mentioned in the short term
discussion. This front will bring behind it cooler air but also a
surface high that will drop winds down to 5 mph or less in the
western CWA, with other areas seeing 5 to 10 mph, going into
Monday morning. Areas in the western Oklahoma Panhandle and the
far northwest Texas Panhandle are looking at seeing temperatures
dropping into the upper 20s, with calm winds and clear skies,
behind the front Monday morning. The southeastern half of the
Texas Panhandle is looking to stay in the mid 30s to very low 40s.
Clear skies behind the cold front Monday will allow temperatures
to at least get into the 60s. Continuing high pressure will keep
winds calm through the day, and will be variable at times. Monday
night into Tuesday will be chilly once again with temperatures in
the low 30s for the northwest and mid 30s elsewhere in the CWA. If
the winds stay below 5 mph and skies stay clear we could see even
lower temperatures than what guidance is giving us at the moment.
Going into Tuesday through Wednesday, we will see gradual warming
in the southern Texas Panhandle with temperatures reaching well
into the 70s. Wednesday night into Thursday morning another cold
front is expected to pass through the area. Lows will drop to near
freezing in the northwest overnight. This front will be associated
with a system that brings more clouds with it on Thursday. Post-
frontal with cloud cover, will hold day time temperatures back,
only reaching the 50s across the CWA.
A second front, or secondary push of colder air will move in
Thursday night into Friday morning. Friday morning will bring
temps into the upper 20s in the northwest one third of the CWA,
and the rest of the CWA will see temps in the low 30s. There are
still some questions about this system that is expected Thursday
night. The GFS has wide spread QPF across the area, while the Euro
only has QPF in the Oklahoma Panhandle. Also, the GFS is still
the only model that shows H85 temperatures below freezing,
allowing for possible snow. With the other models depicting above
freezing temperatures at H85, some wintry mix may be in question
for Thursday night as well. Thursday night is still a ways away.
Therefore, will keep pops below 20 percent and will only have the
possibility for snow in the far northwestern CWA.
Hoffeditz
FIRE WEATHER...
Will convert Fire Weather Watch over western zones
to Red Flag Warning, and will also include remainder of Oklahoma
Panhandle and north-central Texas Panhandle. Fuels have dried
sufficiently over these areas where no appreciable rain has fallen
for the past 2 weeks. Dry southwest winds will shift to northwest
across the north during the morning, and are expected to shift to
west over remaining sections with passage of Pacific cold front.
RFTI values expected to remain highest in the west, with values of 5
to 6 forecast. In newly-added areas, RFTI values of 3 to 5 are
expected, yet with ERCs above the 50th percentile, fuels over at
least parts of these counties will be supportive of fire spread.
Critical fire weather conditions expected to end by 9 PM Sunday.
Cockrell
&&
.AMA Watches/Warnings/Advisories...
TX...Red Flag Warning from 1 PM to 9 PM CDT Sunday for the following
zones: Dallam...Deaf Smith...Hansford...Hartley...Moore...
Oldham...Sherman.
OK...Red Flag Warning from 1 PM to 9 PM CDT Sunday for the following
zones: Beaver...Cimarron...Texas.
&&
$$
98/23
Area Forecast Discussion
National Weather Service Bismarck ND
916 PM CDT Sat Oct 19 2019
.UPDATE...
Issued at 902 PM CDT Sat Oct 19 2019
At 9 PM CDT surface low pressure was located over north central
Wyoming with surface ridging to the east, including western and
central ND. Skies were mostly clear over the forecast area with
mid-high level clouds poised to move into southwest ND, associated
with the storm system that will move across the Dakotas Sunday
through Monday morning. Forecast models are a bit slower in moving
clouds and precipitation into the forecast area tonight. Have
delayed precip arrival until after midnight. The slower arrival
has also allowed temperatures to drop lower than originally
expected. Lowered min temperatures into the lower 30s over a good
portion of the forecast area, with a few readings into the upper
20s possible. Temperatures are expected to rise with the
approaching system, so still expecting just rain.
UPDATE Issued at 529 PM CDT Sat Oct 19 2019
Steep low level lapse rates and weak instability has been enough
for some isolated shower activity over northwest North Dakota late
this afternoon. There was even a few lightning strikes. RAP
soundings do show a period of weak CAPE that is pretty much gone
by early evening. Added a small area of isolated showers across
the northern tier counties through early this evening. For now
will hold off on the thunder. Otherwise no significant changes to
the going forecast.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 215 PM CDT Sat Oct 19 2019
Forecast highlights in the short term period will be weather
associated with a strong storm system impacting western and
central North Dakota late tonight through Monday night.
Currently, embedded wave over northwest Minnesota pushing east,
with only a few lingering mid level clouds across northern areas
of the state. Westerly mixing winds and plenty of sunshine giving
us one more nice day with afternoon temperatures currently in the
50s across western and central ND.
S/WV trough will push east-southeast across the Rockies this
evening, triggering lee side cyclogenesis and closing off over
the high plains of Wyoming later tonight. As this occurs,
increasing cloud cover tonight with chances for rain developing
southwest overnight. Models have trended a tad slower with the
onset of rain and earlier made this tweak in the forecast with a
relatively dry boundary layer initially in place Sunday morning.
As a strong jet streak rounds the base of the upper low, forcing
increases after 12-15Z Sun and this is when we expect a moderate
band of rain to start pushing north into south central ND and
eventually developing east into the James River Valley. POPs were
increased for those areas, while we decreased northwest where
nothing is now expected. Precipitation (mainly rain with some snow
possibly mixing in on the back side) continues central and
especially east Sunday night as the stacked low starts to lift
northeast into Minnesota. Low continues northeast on Monday into
northern MN and will see rain chances ending from west to east
across our region by Mon eve at the latest.
Uncertainty remains still on how much QPF the forecast area will
receive. Models continue to flip flop, but it does appear the
heavier rainfall (1 1.5") will occur across the south central and
over much if not the entire James River Valley (where rain is not
welcome right now). GEFS plumes have converged with QPF, but still
a rather large spread of around half an inch.
Wind will also be an issue. As the low becomes more vertically
stacked and propagates first east and then north, expect winds to
increase along with a tightening pressure gradient as the center
of the low moves through central Minnesota. Winds will be
strongest in the south on Sunday, sustained at 20-25 mph and
gusting up to 35 mph. These will increase on Monday primarily in
the James River Valley and central North Dakota, with sustained
winds up to 30-35 mph and gusting up to 50 mph. Will continue to
mention this in the HWO.
.LONG TERM...(Tuesday through Saturday)
Issued at 215 PM CDT Sat Oct 19 2019
A northwest flow regime will be in place through much of the work
week, followed by an interesting possible end to the week Friday
and Saturday.
Weak area of surface high pressure is projected to be over the
Dakotas Tuesday in the wake of our late weekend storm. Expect
mainly quiet weather with seasonal temperatures in the mid 40s to
lower 50s, though still breezy east.
Strong embedded wave and associated sfc low will quickly move into
and through the Northern Plains Tuesday night-early Wed, bringing
a shot of rain or snow and dragging a cold front south across the
local area. An uptick in winds and cooler temperatures for
Wednesday behind this wave. Some light snow accumulations also
possible, though nothing impactful expected at this time.
Another quiet day for Thursday with sfc high pressure building
across the region. Upper level ridge will be building into the
Pacific Northwest Thursday, then into the Northern Plains/south
central Canada for Friday as it is pushed east by a strong S/WV
moving into western Canada. Mild weather will be possible for
western and central ND for Friday, depending on the timing of WAA
associated with the ridge. GFS waits till Friday night, while the
EC is faster with the arrival of warmer mid level air during the
day Fri. Both models then bring a strong cold front across our
area on Saturday as the aforementioned wave continues east across
southern Canada and closes off. Much uncertainty with this feature
though a cold FROPA looks likely.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 902 PM CDT Sat Oct 19 2019
VFR conditions and a moderate westerly wind to start the 00Z TAF
period. Winds will diminish quickly this evening and shift
southeast to east by 12 UTC Sunday, then shifting northeast to
north and increasing to around 10 to 20 kts by Sunday afternoon
as low pressure tracks across northern South Dakota. Widespread
rain is expected at KBIS beginning around 18Z, and 20Z at KJMS
with MVFR to IFR ceilings and vsbys in rain and fog. KDIK
expecting VCSH, with low VFR ceilings, while KXWA and KMOT remain
dry with VFR ceilings.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...NH
AVIATION...TWH
Area Forecast Discussion
National Weather Service Burlington VT
1053 PM EDT Sat Oct 19 2019
.SYNOPSIS...
Dry weather is expected to persist through Monday night as weak
high pressure remains in control of our weather. As we head
into Tuesday, a strong frontal system will move through the
region and widespread rainfall is expected across the North
Country. Showers will persist through the remainder of the week
but they should be fairly scattered and short-lived. Overall,
after Tuesday the remainder of the week looks pretty nice with
near normal temperatures.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 1050 PM EDT Saturday...Main update at 1030 is that the
temperatures aloft have been colder than expected and are
already dipping into the 20s. Otherwise, no big changes for a
quiet cold night.
Some pesky low clouds have persisted across the northern
Adirondacks and northern Vermont this morning as some moisture
trapped below a surface inversion has had a difficulty mixing
out. Looking at the most recent satellite imagery, it finally
looks like these low clouds are beginning to mix out thanks to
the increasing sun angle this afternoon. This should yield
mostly clear skies by sunset tonight as some weak dry air
advection is noted in the latest RAP data. Temperatures will be
quick to drop tonight with winds becoming nearly calm after
sunset and clear skies persisting. However, we should see
increasing cirrus clouds ahead of post- tropical storm Nestor
and the upper level trough to our west. The increasing cloud
cover should limit radiational cooling after midnight which
should keep temperatures from bottoming out. Because of this,
have increased overnight lows across much of the forecast area.
Widespread frost is still expected across the Champlain Valley
with nearly calm winds and temperatures in the upper 20s to mid
30s.
In addition to the increasing cloud cover, the latest HRRR, RAP
and NAM3 have begun to show an increasing pressure gradient
across northern New York after midnight. It won`t be a lot of
wind but it should be enough to prevent fog development in fog
prone areas of northern New York. The fog prone areas of eastern
Vermont still look likely to fog in as the increasing flow
aloft shouldn`t make it that far east until after sunrise.
Sunday should be another nice day across the North Country as
afternoon high temperatures will be 5-8 degrees warmer than
those observed today. Even though a blanket of cirrus clouds
will move through the region during the daylight hours, warm air
advection associated with increasing mid-level heights and
thicknesses will drive the warming trend on Sunday. It still
looks like the bulk of the moisture associated with post-
tropical Nestor will remain well to our south and have continued
to decrease PoPs in response to this trend. As we head into
Sunday night, we will find ourself in an area of weak flow with
a sharpening upper level trough over the midwest and post-
tropical Nestor to our east. This could set us up into a
favorable pattern for fog Sunday night but details with this
will be ironed out in the next day. With the southwest warm air
advection regime continuing into the overnight hours, lows on
Sunday night will be warmer than tonight with lows in the lower
30s to near 40 degrees.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 314 PM EDT Saturday...Another dry day in store for Monday
as high pressure gradually retreats to the northeast. As the
day progresses, southerly gradient flow will increase ahead of
an approaching system to the west. Highs will generally be in
the low 60s. Monday evening, high clouds will spread over the
region, thickening and lowering through the night. Increasing
warm air advection overnight will limit diurnal cooling, with
lows over northern NY and the Champlain Valley noticeably warmer
than previous nights. Meanwhile further east, eastern Vermont
will be the last to feel the effects of the developing WAA...and
can expect cooler lows in the upper 30s. Winds Monday night are
rather tricky to forecast. A 40+ kt LLJ will move over area,
but for the most part not expecting this momentum to transfer to
the surface with such strong WAA during the overnight hours.
However, any shallow mixing that develops near sunrise could
start to bring down some gusty winds to lower elevations.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 314 PM EDT Saturday...A vertically-stacked low pressure
system centered over western Ontario will push a cold front
eastward through the forecast area late Tuesday into Tuesday
night. At the same time, a fairly robust shortwave will round
the base of the upper-level low, becoming slightly negatively
tilted as it rotates through New England. Ahead of the boundary,
increasing southerly flow will result in some gusty southerly
winds (mainly in the 15 to 25 mph range for gusts) during the
day Tuesday before the rain starts. The increasing southerly
flow/moisture transport ahead of the boundary will feed into a
region of moderate ascent over the North Country, resulting in a
wetting rainfall as the boundary moves through later Tuesday
into Tuesday night. However, low-level convergence along the
front is not overly impressive given the occluding nature of the
boundary with southwesterly flow to the west. In addition,
depending on timing of front, upper jet placement may not be
conducive to the best lift.
One wildcard that will have to be watched closely in this setup
will be the potential interaction of the trough moving in from
the west with the remnants of Nestor to our east. While Nestor
itself will stay well offshore as it tracks northeastward over
the western Atlantic Monday through Tuesday, the system will
steer onshore flow towards New England. This increases the
potential moisture advection into the region ahead of the cold
front , although at this point it`s unclear how much additional
moisture will make it this far north and west of the coast. Will
be keeping a close eye on the interaction between Nestor and
the system approaching from the west, but for now doesn`t look
like Nestor will have much of an impact on the BTV forecast
area.
By Wednesday morning, front will be to our east and post-
frontal southwesterly flow will commence. The upper-level low
will continue to send numerous shortwaves through the
northeastern US Wednesday through Thursday night. This will keep
some clouds and potential for some spotty light showers in
place, especially in the lee of Lake Ontario where moisture will
be locally enhanced. The unsettled, showery pattern will
continue through the week. Chances for more widespread
precipitation return over the weekend as a low pressure system
potentially tracks into the area, although details are murky
this far out.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...All terminals are starting VFR tonight.
Skies are clear and winds mainly light. Fog still looks likely
at MPV and eastern Vermont as the winds won`t make it in until
12Z-14Z. VFR conditions will once again persist on Sunday with
winds shifting to the southeast after sunrise.
Outlook...
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: Mainly VFR, with local MVFR possible. Likely SHRA.
Tuesday Night: Mainly VFR, with areas MVFR possible. Definite
SHRA.
Wednesday: Mainly VFR, with areas MVFR possible. Chance SHRA.
Wednesday Night: VFR. Slight chance SHRA.
Thursday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Frost Advisory until 9 AM EDT Sunday for VTZ001-002-005-009.
NY...Frost Advisory until 9 AM EDT Sunday for NYZ028-035.
&&
$$
SYNOPSIS...Clay
NEAR TERM...Clay/Neiles
SHORT TERM...Duell
LONG TERM...Duell
AVIATION...Clay/Neiles
Area Forecast Discussion
National Weather Service Columbia SC
814 PM EDT Sat Oct 19 2019
.SYNOPSIS...
Nestor will continue to lose tropical characteristics as it
tracks northeastward and through the forecast area tonight. The
system will bring significant rainfall to the area along with
breezy conditions. Dry high pressure behind the low will be
over the area Sunday. A cold front will approach Monday and move
through the forecast area early Tuesday. Much of the moisture
will be ahead of the front Monday night.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
The center of the remnants of Nestor was located over southern
Ga at 00z moving northeast. Strong and deep convection has
developed near the storm center over the past couple of hours.
The convection is located near the warm front. The convection
has showed a weakening trend based on satellite and radar
images. The air mass across central SC and the CSRA is remains
stable. However, it is possible a more favorable environment for
convection including a few supercells may develop mainly across
eastern SC/GA later this evening...after 03z. This is supported
by RAP and HRRR guidance. Will continue to monitor radar and
satellite trends but there remains a low chance of an isolated
tornado across mainly the east Midlands overnight.
Rainfall has been light to moderate across the area this evening
with relatively strong warm advection/isentropic lift across the
area northeast of the storm center. Rainfall will likely
increase over the next few hours as the remnant storm center
approaches then moves over the area. Locally heavy rain possible
but flood threat appears low due to dry antecedent conditions
coupled with fast storm movement and limited QPF earlier in the
day.
Breezy conditions remain possible...model soundings and radar
vad wind profiles show 40 kts around 2000 ft...but stable near
surface layer/inversion resulting in winds mainly 10 to 20 mph.
Will continue Lake wind advisory with stronger mixing on lakes.
Rainfall should diminish after 09z as the storm moves to the
northeast of the area. Temperatures should remain nearly steady
or rise a bit overnight in the 60s.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Post Tropical Storm Nestor is forecast to move off the NC coast
Sunday. Precipitation should lift northeast of the Midlands
during the early morning hours Sunday.
Dry ridging is forecast to be in the region Sunday and Sunday
night.
High Sunday should be in the mid 70s to around 80 as skies
clear and winds diminish. Lows Sunday night are expected to be
in the 50s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The models depict a progressive fall weather pattern during the
medium-range period. Ridging is forecast to move off the coast
early Monday ahead of an approaching cold front. The front is
expected to cross the area Tuesday. The models depict the
deepest moisture ahead of the front Monday night into early
Tuesday. The dry air mass behind the front should dominate
Wednesday and Thursday. Moisture may increase again ahead of
sharpening upper troughing and as associated cold front Friday.
The GFS and ECMWF MOS support near-normal temperatures during
the period.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Moisture associated with the remnants of Nestor continue to
result in flight restrictions, with prevailing IFR ceilings and
occasional IFR visibilities at all terminals within steady
light to moderate rain. The rain will begin to taper off after
about 08-09Z as the remnant low passes the area, but the low
ceilings will prevail well through Sunday morning as wrap-around
low level moisture persists. The low clouds should begin to
scatter out with VFR conditions developing around mid-afternoon
Sunday.
Strong low level winds will continue ahead of the remnant low,
with 40-45 kt winds depicted by models and showing up on the
KCAE VAD Wind Profile around 2k feet. However, an inversion has
significantly limited the vertical mixing to the surface where
winds will generally remain around 10 kt or less. Given this,
low level wind shear will be maintained in the TAFs through at
least 09Z, and may need to be extended for several more hours
beyond that.
EXTENDED AVIATION OUTLOOK...Widespread IFR fog may occur late
Sunday night and Monday morning because of noctural cooling
combined with high low-level moisture and light wind.
Restrictions may occur Monday night into Tuesday associated with
a cold front. Gusty winds may occur just behind the front
Tuesday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...Lake Wind Advisory until 2 AM EDT Sunday for GAZ040-063>065-
077.
SC...Lake Wind Advisory until 2 AM EDT Sunday for SCZ016-018-
020>022-025>031-035>038-041-115-116.
&&
$$
Area Forecast Discussion
National Weather Service Dodge City KS
605 PM CDT Sat Oct 19 2019
...Updated Aviation Discussion...
.SHORT TERM...(This afternoon through Sunday night)
Issued at 1130 AM CDT Sat Oct 19 2019
A weak transitory surface high pressure ridge axis will provide
for a splendid autumn afternoon, with winds diminishing to light
and variable over the next few hours. Afternoon temperatures very
near normal.
Southeast to south winds will increase tonight, as high pressure
retreats eastward, establishing return flow, and a low level jet
develops after midnight. South/southeast winds will remain
elevated and gusty all night, gusting 25-30 mph. Mid level clouds
will increase from west to east tonight (especially toward
sunrise), as shortwave energy arrives from the west. With south
winds keeping the boundary layer mixed, temperatures will only be
allowed to fall to the 40s. Most likely, temperatures will quickly
fall to the 40s this evening under a clear sky and light winds,
and then remain steady/slowly climb through the 40s through
sunrise.
Models deepen a 545 dm 500 mb low in eastern Wyoming sunrise
Sunday, to a 542 dm closed low in central Nebraska 7 pm Sunday.
This synoptic evolution is a classic dry slot scenario for SW KS,
and removed what little pops we had in the grids. All locations
will be dry, with just an increase in mid/high clouds as the
Pacific cold front arrives daytime Sunday. Elevated gusty south
winds at sunrise Sunday will veer to W/SW Sunday morning, and
continue to veer NWly behind the frontal passage through Sunday
afternoon. Very little cold air advection will be associated with
these NW winds, and what little there is will be masked by a
warming downslope component, keeping afternoon temperatures in the
upper 60s and lower 70s for most zones. Southeast counties will
have ample opportunity to warm well into the 70s before frontal
passage. The NW winds will be accompanied by strong dry advection,
with dewpoints falling into the teens and 20s by afternoon.
Pattern recognition suggests NW winds will be quite strong in the
afternoon, but model guidance is curiously weaker than what would
be expected. Went above the guidance and continued to show NW wind
gusts of 30-40 mph in the afternoon across the NW 1/2 of SW KS.
Winds will be weaker SE of Dodge City.
The sky will clear Sunday night, under subsidence and dry/cool
advection. Temperatures sunrise Monday in the 30s west and 40s
east.
.LONG TERM...(Monday through Saturday)
Issued at 155 PM CDT Sat Oct 19 2019
Monday...cool and breezy with elevated NW winds, on the backside
of a strong cyclone over the upper Mississippi valley. 850 mb
temperatures are at their coolest Monday, but the combination of
sunshine and NWly downslope components will allow most locations
to achieve the lower 60s, just a few degrees below normal. NW
winds of 20-30 mph will be common, especially near I-70, nearest
the departing cyclone.
Tuesday...quiet, sunny and warmer with less wind. Heights rise
nicely, and with a W/SWly downslope component returning, afternoon
temperatures will easily warm through the 60s, into the lower 70s
at many locales.
Wednesday...still dry and quiet (daytime hours), as flow aloft
becomes zonal, in response to strong shortwave diving into the
northern Rockies. 12z ECMWF depicts a strong cold front associated
with the shortwave diving down the Colorado Front Range/high
plains Wednesday afternoon. Currently, it appears all zones will
have sufficient time to warm into the 60s before this cold front
blasts through with strong north winds Wednesday night.
All models generate widespread upslope-generated QPF Wednesday
night/early Thursday, most of it snow, from the Colorado Front
Range extending eastward into SW KS. The vast majority of
accumulating snow will fall close to the I-25 corridor, but
frontogenetic forcing will support a precipitation band passing
south through SW KS roughly early Thursday. Atmosphere will be
cold enough to support rain changing to wet snow. This is not
expected to be a major winter storm. That said, feel NBM pops are
too dry/low (given 12z MEX pop for Dodge City is 58%). Increased
pops for a light QPF event are expected with future model runs.
Thursday will be much colder (likely colder than the NBM) with
temperatures struggling through the 40s in the afternoon.
Freezing temperatures are expected Friday morning, beneath a
strong surface high pressure ridge, before temperatures moderate
quickly through Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 604 PM CDT Sat Oct 19 2019
Light southerly winds this evening will gradually increase
overnight as a trough of low pressure develops and deepens over
eastern Colorado. The south southeast winds will increase to
around 15 knots between 09z and 12z Sunday and become gusty. A 45
to 55 knot low level jet is forecast to develop across western
Kansas late tonight so include wind shear in the 00z TAFS between
09z and 15z Sunday. The surface lee trough/dryline will move
across western Kansas early in the day and will be followed by a
cold front as an upper level trough exits the Central Rockies and
moves out into the West Central Highs Plains. The latest RAP and
NAM both are in good agreement in moving this boundary east of
Hays and Dodge City by 18z. As this boundary passes the gusty
southerly winds at 15 to 20 knots early Sunday morning will shift
to the west/northwest. Ahead of an approaching upper level trough
clouds will begin to increase from the west in the 6000 to 1000 ft
AGL level during the day on Sunday.
&&
.FIRE WEATHER...
Issued at 1239 PM CDT Sat Oct 19 2019
Upgraded the inherited fire weather watch for Sunday afternoon and
evening to a red flag warning. Winds will become NW and increase
during the peak heating/early afternoon hours, with the strongest
winds expected NW of a Dighton-Garden City-Johnson line. Here, NW
winds will average 20-30 mph with gusts near 40 mph. NW winds for
the remainder of the red flag warning will be more marginal, but
strong dry advection will force minimum relative humidity to the
10-15% range across all of the red flag warning area. Areas near
the Colorado/Kansas border are most likely to achieve red flag
criteria for several hours Sunday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 70 38 62 / 0 0 10 0
GCK 44 68 35 62 / 0 0 10 0
EHA 45 69 33 63 / 0 0 10 0
LBL 45 73 35 63 / 0 0 10 0
HYS 48 66 39 60 / 0 10 10 0
P28 45 74 44 65 / 0 10 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon CDT /11 AM MDT/ to 8 PM CDT /7 PM
MDT/ Sunday for KSZ043-044-061>063-074>077-084>087.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Burgert
FIRE WEATHER...Turner
Area Forecast Discussion
National Weather Service Duluth MN
1010 PM CDT Sat Oct 19 2019
.SHORT TERM...(This evening through Sunday night)
Issued at 359 PM CDT Sat Oct 19 2019
A cold front has exited the Northland this afternoon and shortwave
ridging will develop overnight. Skies will clear over far eastern
areas late this afternoon and it will remain mostly clear tonight.
There may be some patchy fog tonight, especially over northwest
Wisconsin. The mostly clear skies and light winds will lead to lows
in the lower to mid thirties. An upper low will move into South
Dakota on Sunday and a surface low will be in nearly the same area.
Clouds wil be on the increase through the day with it becoming
mostly cloudy during the afternoon over western areas. We kept the
day dry as most guidance holds off on precipitation until the
evening and forecast soundings are quite dry below 700MB through.
00Z Monday. We bumped highs up a bit for Sunday and have highs in
the upper fifties to lower sixties.
.LONG TERM...(Monday through Saturday)
Issued at 359 PM CDT Sat Oct 19 2019
Main concern in the extended is widespread rain late on Sunday
through much of Tuesday. Expecting strong winds as the system lifts
north of the region late on Monday and Tuesday. Temperatures
trending downward as the week progresses.
A neutrally tilted trough will lift from the High Plains Sunday
evening into the Upper Mississippi River Valley and become
negatively tilted on Monday. As the surface low pressure will lift
from the High Plains into Minnesota. Models have slowed down a bit
on the onset of precipitation and have tried to reflect this by
slowing down precipitation chances Sunday night. Even though we are
only 36 to 54 hours out models still diverge a bit on the surface
low track. The NAM is an outlier with the low much further east than
the GFS, GEFS, ECMWF and GEM. The GEFS and GFS solutions are similar
with the low track a bit further north across northeast Minnesota,
while the ECMWF and GEM track the low along the Minnesota and Iowa
border. This will have implications for the Northland as a more
northerly track would likely bring the dry slot into the area which
would reduce precipitation totals. A more southerly track would
bring more precipitation to the region. At this point in time the
WPC Super Ensemble shows QPF values clustering roughly between 1 to
1.5 inches Sunday night through Tuesday. The system will lift over
the Northland through Monday into Ontario on Tuesday which will
gradually taper off precipitation Tuesday night from southwest to
northeast. It is during this timeframe where there is the best
chance for rain becoming snow, however no accumulation is expected.
There is some instability present Sunday night through Monday. This
will couple with strong QG forcing and may bring some isolated
thunderstorms to the region. Severe storms are not expected.
The other concern with this strong fall system is strong winds on
Monday and Tuesday. The tight pressure gradient over the region will
bring easterly winds early on Monday becoming northerly with speeds
of 5 to 15 mph and gusts of 15 to 25 mph by the afternoon. Winds
will become more westerly or northwesterly late on Monday into
Tuesday as the low lifts into Ontario. Expect sustained wind speeds
Monday night of 10 to 25 mph with gusts of 15 to 35 mph. Increased
wind speeds on Tuesday from the previous forecast with sustained
winds ranging from 15 to 25 mph. Gusts at this point in time are 20
to 35 mph. Several pieces of deterministic guidance suggest that
gusts may be around 45 mph per the GFS, NAM and ECMWF. If models
continue to trend in this direction then a Wind Advisory may be
needed.
The low pressure system will continue rotating across northern
Ontario on Wednesday and Thursday. This will bring scattered rain
shower chances for much of the region due to the colder air
advecting in aloft combined with some daytime heating and cyclonic
flow over the region. Confidence lowers late in the week as model
significantly diverge in solutions. Low temperatures will be in the
mid 20s by late in the week. Highs will drop into the upper 30s and
mid 40s by Thursday and Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1229 PM CDT Sat Oct 19 2019
VFR through the forecast with high pressure building in. High
confidence in breezy conditions this afternoon in wake of the cold
front per the GFS, NAM and RAP guidance. Any gusty winds will
subside this evening as the mixed layer decouples and winds become
light.
Confidence is low in the possibility of MVFR conditions at INL and
HYR. The NAM, GFS and RAP hint at the MVFR stratus moving in from
southern Manitoba to INL. Not sure if this stratus will continue
to advance as the high builds in, but have hinted at the
possibility. Late tonight have medium confidence in radiation fog
development at HYR due to recent precipitation, clearing skies and
light winds. Most guidance does not show fog development, but the
ARW and NMM do have LIFR fog developing east of HYR. Leaned on the
ARW, NMM and past experience to at least hint at fog for HYR.
Any fog will lift by early Sunday morning as the mixed layer
grows. Winds will remain less than 10 knots with high pressure
sliding east of the region.
&&
.MARINE...
Issued at 1009 PM CDT Sat Oct 19 2019
Fairly quiet as high pressure builds overhead. A strong system
approaches Monday morning and will likely bring strong small craft
winds and maybe even gales to the waters Monday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 35 59 44 49 / 0 0 50 90
INL 36 58 43 49 / 0 0 50 80
BRD 35 59 46 50 / 0 10 90 90
HYR 36 61 46 54 / 0 0 40 90
ASX 36 60 44 55 / 0 0 30 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
SHORT TERM...Melde
LONG TERM...WL
AVIATION...WL
MARINE...Wolfe
Area Forecast Discussion
National Weather Service Goodland KS
835 PM MDT Sat Oct 19 2019
.UPDATE...
Issued at 835 PM MDT Sat Oct 19 2019
Have updated the forecast through early Sunday evening.
Main concerns are for fire weather and blowing dust Sunday.
Current Red Flag Warning area looks good based on 00z data.
Have adjusted the blowing dust threat to areas generally from
McCook to Goodland and Flagler west. This area is under favorable
surface to 1km winds, mainly after 21z through about 01z where
good mixing will also occur. Local ongoing research shows better
chances for blowing dust exist with wind gusts exceeding 35kts,
higher probabilities with gusts over 40kts which looks likely in
the northwest portion of the area. Soil moisture is very favorable
given dry conditions the past several days. My thinking is that a
plume or two of dust could originate in northeast Colorado,
northwest of our forecast area, and move toward the southeast into
our area from late afternoon toward sunset. Confidence isnt
terribly high but its certainly possible. Dust dispersion models
hint at this scenario as well.
Will also have to monitor the possibility of a High Wind Warning
being needed for Yuma county. Currently have wind gusts to 55 mph
in updated forecast. 0.5-1km winds reach 50kts in the northwest
corner of the county around 00z Monday. 00z HRRR shows a small
area of 50kt wind gusts in this area around 23z.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 337 PM MDT Sat Oct 19 2019
Mostly zonal flow aloft was dominating over the Tri-State area
earlier today along with low level CAA moving in behind a weak
cold front that passed through the area this morning. Skies have
cleared out and highs only got into the mid to upper 60s. Our
surface flow will become southwesterly shortly before turning
south as another shortwave moves across our area from the
southeast tonight. Winds are also expected to increase with this
system coming through, and skies will become more cloudy as a
result.
Tomorrow the trough will strengthen over the rockies leading to
the pressure gradient over our area tightening and increasing
winds ahead of this system. We are still forecast to dry out,
dropping our RH values in the lower teens for the southern half of
our CWA. Looking at guidance, winds will become west 15 to 25 mph
increasing at peak afternoon heating to around 25 to 35 mph with
gusts potentially up to 45-50 mph.
As a result, felt it was a no-brainer to go ahead and upgrade the
Fire Weather Watch to a Red Flag Warning. Kept the same counties
at this time as confidence wasn`t high enough to expand the
warning any further north, but that may change tonight on the
midnight crew`s watch. Timing is a little difficult because as the
trough deepens and start to trek east, we will see an increase in
moisture to our area ahead of the system. So, as of now, thinking
if we do reach critical fire weather criteria, for counties not
in the warning, it will be very brief in time, and more isolated
to our southeastern counties.
Lastly, for Sunday afternoon, because we are so dry and this time
of year, we are is still a risk of patchy blowing dust across the
entire Tri-State area.
Monday is looking less likely to met fire weather thresholds, so
kept it out at this time, but blowing dust could be possible as
winds are expected to be sustained around 20 mph. Looking at flow
aloft, we will switch back to the northwest after the trough has
moved out of our area. As a result, we will see clearing skies
with highs in the mid 50s. and overnight lows in the lower 30s.
.LONG TERM...(Sunday night through Saturday)
Issued at 230 PM MDT Sat Oct 19 2019
The CWA lies on the backside of a lifting trough Monday. A ridge
moves across the Tri-State area Tuesday. An upper level trough
begins to extend from the previous low, now over north-east Canada,
into the central Plains by Thursday. This trough moves across the
central U.S. through Friday morning as another ridge approaches. A
new trough swings southeastward into the northwest Plains Saturday.
Surface leeside troughing sets up along the Front Range Tuesday. As
the associated low moves out of the Tri-State area, a cold front
passes through Wednesday bringing precipitation in the form of rain
and snow. Dry conditions return Thursday night as high pressure
moves into the area. Another cold front moves into the northern
Plains Saturday causing leeside troughing to redevelop along the
Front Range.
High temperatures will range from the mid-40s to upper 60s through
the extended forecast period. Lows in the 20s to mid-40s are
expected. Monday and Wednesday could be breezy with winds from the
north-northwest at 15-25mph and gusts up to 35 mph. Aside from
Wednesday and Thursday when the precipitation and front are
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 450 PM MDT Sat Oct 19 2019
For KGLD and KMCK, vfr conditions through the period. South to
southeast winds will slowly increase overnight with KGLD seeing
the strongest winds at speeds sustained at 15 to 20kts with higher
gusts. On Sunday winds will veer to the west then northwest at
KGLD with gusts 35kts expected in the afternoon. At KMCK west
winds will increase with gusts near 35kts expected in the
afternoon.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Red Flag Warning from 11 AM MDT /noon CDT/ to 8 PM MDT /9 PM
CDT/ Sunday for KSZ013-027>029-041-042.
CO...Red Flag Warning from 11 AM to 8 PM MDT Sunday for COZ253-254.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...EV
LONG TERM...NEWMAN
AVIATION...99
Area Forecast Discussion
National Weather Service Green Bay WI
1016 PM CDT Sat Oct 19 2019
Updated aviation portion for 06Z TAF issuance
and new information added to update section
.UPDATE...
Issued at 957 PM CDT Sat Oct 19 2019
Clearing has not materialized this evening, as satellite and
surface observations show widespread low stratus covering most
of north central and central WI. Expect the stratus to gradually
lower into a fog deck overnight, and any localized areas of
clearing should also fog in quickly. Based on a blend of forecast
visibilities off various meso-models, and the arrival of a ridge
axis over our western counties, expect fog to be most widespread
(and locally dense) over north central and central WI overnight
into early Sunday. The Fox Valley may also see locally dense fog.
Have already issued a Special Weather Statement to highlight the
areas at greatest risk for hazardous travel into Sunday morning.
&&
.SHORT TERM...Tonight and Sunday
Issued at 254 PM CDT Sat Oct 19 2019
The latest RAP analysis and satellite/radar imagery show a cold
front moving across Wisconsin early this afternoon. A band of rain
is accompanying the front, within a region of mid-level fgen and
moisture convergence. This rain is moving across areas from
Rhinelander to Wisconsin Rapids and will slowly track east into
northeast Wisconsin by late afternoon or early this evening.
Clearing skies are moving across eastern Minnesota behind the
front. Forecast concerns generally revolve around precip trends
and potential for dense fog late tonight.
Tonight...The cold front will continue to march east and move into
Lake Michigan by roughly 06z. The short range models generally
show the band of rain weakening as it moves into the eastern part
of the state due to diminishing mid-level fgen. Skies remain
expected to quickly clear behind the front, with a weak surface
ride axis settling across the region. Because of the clear skies
and light winds, conditions will support fog formation late
tonight. Statistical guidance has appeared to have backed off on
the fog potential, but the href hits central and north-central WI
relatively hard. This makes sense as these areas will see the most
rainfall and coolest temps today. Locally dense fog appears
possible in this area. Lows tonight are expected to fall into the
mid 30s over north-central WI to the mid 40s near the lakeshore.
Sunday...Morning fog may persist until 9 or 10 am. Otherwise,
should see a nice fall day with only high clouds invading the
region from the southwest during the afternoon. Temps will be mild
and range from the upper 50s to low 60s for most locations.
.LONG TERM...Sunday Night Through Saturday
Issued at 254 PM CDT Sat Oct 19 2019
The negatively tilted upper trough over the Northern Plains will
intensify as jet energy continues to rotate around it Sunday night
through Tuesday as it lifts slowly northeast towards the Minnesota
Arrowhead and then northern Lake Superior.
Dry air ahead of the system should keep the forecast area dry at
least through the early morning hours Monday. Gulf moisture should
arrive during the day Monday and produce an inch or so of rain in
most areas, with perhaps more across central and northern counties.
There could be a few thunderstorms south of a Green Bay to Wausau
line with elevated instability. Temperatures Sunday night will be
held above normal due to cloud cover. Highs Monday should be a
few degrees above normal with southerly winds bringing in warmer
air from the south.
As the surface low intensifies Monday night and Tuesday, gusty
west winds will bring slightly colder air into the region, along
with showers. The air aloft doesn`t appear cold enough for anything
but rain at this time. Gale force wind gusts are possible late Monday
night through Tuesday. Mainly dry and cool weather should follow
for Wednesday through the end of the week.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 957 PM CDT Sat Oct 19 2019
A weakening band of light showers was pulling out of far northeast
WI late this evening, and should be east of the region by TAF
issuance. Widespread stratus with IFR ceilings covered north
central and far northeast WI. Patchy fog was developing wherever
localized clearing had occurred.
Expect the stratus deck to lower into a fog deck overnight, with
possible LIFR/VLIFR conditions developing over north central and
central WI, and possibly the Fox Valley. The fog is expected to
dissipate by around 15z, followed by VFR conditions for the
afternoon and evening.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........Kieckbusch
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1024 PM EDT Sat Oct 19 2019
.SYNOPSIS...
The remnants of Tropical Storm Nestor will continue to track across
southern Georgia and South Carolina through the overnight. Brief
drying returns by mid-day Sunday, before an active cold front
crosses the area Monday night into Tuesday. Dry high pressure builds
in on Wednesday, with another moist frontal system affecting the
region late in the week.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1000 PM: The center of circulation of Post-Tropical Cyclone
Nestor was nearing Eastman, Georgia and continuing to advance
northeast toward the coastal plain of South Carolina late this
evening. The instability gradient continues to wrap westward across
the Low Country of South Carolina and the latest RAP model run has
some measure of positive surface-based buoyancy reaching roughly an
Augusta to Columbia to Chesterfield line by 09Z. Despite the
improving 850 to 700 mb flow north of the circulation across our
region, and the associated uptick in deep layer bulk shear values to
40 to 45 kt, it appears rather unlikely that an overlap of
instability and shear will reach the lower piedmont. Will keep a few
isolated rumbles of thunder in the forecast for eastern sections
overnight, but severe weather looks rather unlikely at present.
There is still a reasonably strong band of mid-level frontogenesis
featured on the back side of the passing remnant low center, and
this could lay down a stripe of nearly two inches of rainfall in the
lower piedmont overnight. Amounts may be greatest from Chester to
Monroe and points east, but fortunately these locations have not
experienced the heaviest rainfall thus far today. Thus, the hydro
threat remains relatively low as the heaviest showers are shared
around the region and falling on soil with dry antecedent conditions
prior to today.
Precip will likely end from the southwest by around 12z over most of
the area. Winds will be upslope against the Appalachian spine at
that time, supporting a small PoP there for a few additional hours.
It appears winds will take some time to go uniformly downslope
across the area, and it may take until noon, or later in the eastern
zones, for the low clouds to break up completely. Many aspects of
this event bear similarity to CAD wedge development and erosion.
Temp trends thru the overnight hours are no exception; values likely
will remain nearly steady overnight if not rising slightly when
precip diminishes. Aided by downsloping and the clearing skies,
temps tomorrow will be quite a change from today, generally rising
into the 70s, with values closer to 80 over parts of the Savannah
River Valley and western Upstate.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 143 PM EDT Saturday: With what`s left of Nestor long gone by
Sunday night, our attention will turn to the next system, that being
a strongly-forced cold front approaching from the west on Monday
and crossing the region early on Tuesday. Probably. Before we get
there, Sunday night will be quiet as high pressure ridges down from
the north in the wake of the Nestor remnants, but low temps will
remain on the order of 5-10 deg above normal. On Monday, as the
front approaches, a southeasterly upslope return flow will develop
through the day, so shallow rain showers are still a possibility
close to the Blue Ridge Escarpment. The fcst favors a small chance
in that vicinity per the model blends and statistical guidance, in
spite of the operational model output being mainly dry through 00Z
Tuesday. The cold front will be making its way east at a steady clip
on Tuesday evening, so precip chances will quickly escalate from
west to east during the Tuesday night period. Precip looks like a
safe bet across the mtns and foothills early Tuesday morning...but
at that point, model differences start to come into play, casting
some uncertainty. The GFS and ECMWF generally have a fropa early
in the day on Tuesday, essentially east of the fcst area by 18Z,
while the NAM is six hours slower. The problem with the NAM is
that it would raise the stakes for some severe weather threat,
at least over the eastern zones in the afternoon as the Charlotte
metro area would be uncovered and might realize sbCAPE upwards of
500 J/kg while shear on the order of 35-40kt was still around. The
faster GFS does not develop this high-shear/ low CAPE environment,
at least not until the front is well to our east. The fcst favors
the faster solution for the time being, as the GFS ensemble also
has the front to the east by 18Z. Thus, precip chances end by the
end of the day Tuesday.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 130 PM EDT Saturday: No major changes were made to the going
fcst. The upper pattern becomes zonally flat early Wed which will
support a broad 1023 mb sfc high across the SE CONUS Wed thru most
of Thu. Cross sections show deep-layered dry air in place and PWATs
dropping below 0.35 inches both days. Thus...good insol and mixing
of td/s will be had...while temps reach near normal levels. Winds
will remain weak...so two rather pleasant fall days are in store.
Moisture begins to increase within the upper levels Thu afternoon
ahead of a deepening upper trof across the Midwest. This system will
be the next precip maker for the area early Fri into Sat as it
interacts with a weak sfc wedge leftover from the exiting cP
airmass. The models continue to show differing ideas with the
evolution of the system...with the ECMWF much quicker and phased
better than the GFS and the CMC solns. The GFS is more aggressive and
moist with an elevated warm front Fri...which coincides with the
pre/frontal moist seen on the ECMWF...so PoPs were kept in the high
chance range thru most of Fri. On Sat...confidence continues to
decrease as the ECMWF crosses the frontal zone east of the FA while
the GFS lingers good lift and moisture over the region. So...will
mention low-end chance PoPs for now. Thunder chances will be small
due to warm mid-levels...however the GFS is showing some elCAPE
across the ern zones as the wedge retreats which could lead to a few
general tstms in the later afternoon into the evening. Temps will be
held a cat or so below normal Fri/Sat due to high amts of moisture
and decent coverage of precip.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Showers will continue into the early morning
hours across the terminal forecast area as the remnant circulation
of Nestor passes to the east. Where not already IFR, conditions will
quickly deteriorate to IFR under the heavier showers and remain that
way through the overnight hours. Both thunderstorms and low-level
wind shear conditions may flirt with the KCLT vicinity from mainly
06Z to 09Z, but expect both conditions to remain generally a county
or two east of the airfield. Although precipitaion will taper off
from southwest to northeast by daybreak, low clouds will take most
of the morning to scatter, and they could linger into the early
afternoon at KCLT. Expect northeast winds to gust into the 20 to 25
kt range at times through early overnight, except in the more
sheltered NW flow at KAVL. Steadier N to NW winds are expected
through Sunday at less than 10 kt as the Nestor remnants move away
to the northeast.
Outlook: Generally VFR expected late Sunday, but some nocturnal
restrictions may develop Sunday night. The next system approaches
late Monday night with precipitation and periodic flight
restrictions likely. VFR will return Tuesday and last for most of
the work week.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT Med 79% Med 68% High 92% High 100%
KGSP Med 68% Med 73% Med 70% High 100%
KAVL High 83% Med 73% Med 61% High 100%
KHKY Med 71% Med 78% Med 76% High 100%
KGMU Med 76% Med 73% High 81% High 100%
KAND Med 71% Med 62% Med 61% 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
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...SBK
NEAR TERM...HG
SHORT TERM...PM
LONG TERM...SBK
AVIATION...HG
Area Forecast Discussion
National Weather Service Lake Charles LA
855 PM CDT Sat Oct 19 2019
.UPDATE...
Will maintain Coastal Flood Advisory as high tide is occurring
and criteria has already been reached at Amerada Pass.
An unseasonably warm night is forecasted as temperatures over most
of the area are well into the 70s. Water vapor and UA analysis are
showing upper jet streak approaching central Texas. Good warm
advection is developing above the boundary layer ahead of this
feature across southeast Texas. This may be sufficient for some
showers to develop overnight over western parts of the forecast
area. HRRR during the past few runs was hinting at slightly
stronger convection over the southeast Texas Lakes region. May
tweak POPs slightly higher over that area. No other updates
planned.
&&
.PREV DISCUSSION... /issued 806 PM CDT Sat Oct 19 2019/
AVIATION...
Looking at VFR thru the evening hours into the overnight hours.
Clouds to start moving in after sunrise. VFR thru the forecast
cycle.
PREV DISCUSSION... /issued 359 PM CDT Sat Oct 19 2019/
SYNOPSIS...
Elevated tides to bring the possibility of minor coastal flooding
right along the coast and inland of coastal lakes and bays during
high tide through Sunday night.
Strong to Severe thunderstorms along with locally heavy rainfall
possible ahead of a cold front on Monday.
Fair weather expected behind the front through mid week.
Rua
DISCUSSION...
A rather warm day with mostly sunny skies allowing temperatures to
rise into the low to mid 80s. Weak high pressure will move away
from the region and this will allow some moisture to return
tonight into Sunday. A southern stream disturbance will help
interact with the moisture to produced some scattered light rain
showers.
A rather potent upper level disturbance moving down from the
Pacific Northwest will develop a mid latitude cyclone over the
Plains on late Sunday. This system will move off to the east and
help push a cold front across the forecast area during the day on
Monday. Timing among the guidance members are in the ball park
for frontal passage during late Monday afternoon.
Instability and lapse rates are rather modest ahead of the front.
However, decent low level jet is noted possibly being bisected by
a mid level speed max. Therefore, shear numbers will be decent.
So there will be the possibility of some strong to low end severe
storms. SPC has an area northeast of a Toledo Bend to Opelousas
line outlined in a Slight Risk for severe storms, with the
remainder of the area in a Marginal Risk. Straight line wind gusts
will be the main hazard, although an isolated tornado can not be
ruled out.
The southerly winds will also bring in ample Gulf moisture with
precipitable water values increase to near 2 inches. Therefore,
some locally heavy rainfall will also be possible from intense
rainfall rates in the stronger convection that may allow for
street flooding or flooding of poor drainage areas. WPC has
outlined the entire forecast area in a Marginal Risk for Excessive
Rainfall.
Drier and cooler air will then move in behind the front proving
for a nice Tuesday and Wednesday, before the cycle starts all over
again ahead of a cold front on Friday.
Rua
MARINE...
With Nestor becoming extratropical and moving across the Florida
Panhandle and further away from the region, and low pressure
developing over the Southern Plains, winds will continue to become
onshore overnight. These southerly winds will increase on late
Sunday into Monday as the low deepens and moves into the Northern
Plains. Small craft exercise caution may be needed during the
Sunday night into Monday period as winds approach 20 knots and
seas build to near 6 feet.
A cold front is then expected to move across the coastal waters on
late Monday. A few strong thunderstorms may occur ahead of the
front with locally higher winds and seas, along with occasional to
frequent cloud to water lightning.
North winds are expected to increase behind the front with speeds
over 20 knots and a small craft advisory is possible for Monday
night into Tuesday. High pressure behind the front will move off
to the east on Wednesday, with a moderate easterly flow expected.
Rua
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 82 66 86 72 / 0 30 30 30
LCH 84 72 86 75 / 0 10 20 40
LFT 84 68 86 74 / 0 0 40 30
BPT 84 72 86 75 / 10 10 30 50
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 7 AM CDT Sunday for LAZ041-052>054-
073-074.
TX...Coastal Flood Advisory until 7 AM CDT Sunday for TXZ215-216.
GM...None.
&&
$$
PUBLIC...04
Area Forecast Discussion
National Weather Service Miami FL
809 PM EDT Sat Oct 19 2019
.UPDATE...
The center of post-tropical Cyclone Nestor was located across
southern Georgia this evening. Robust warm air advection ahead of
this system extended from the Carolinas through the western
Bahamas, with a residual low-level moisture feed extending across
south Florida on southwesterly winds. This is evident via
Satellite derived precipitable water values of 1.9 to 2.3 inches.
While the better thermal advection has departed to our east, the
latest RAP analysis suggests several small pockets of modest
850-700 mb warm advection are yet to rotate through our area
tonight. There is enough turning in the low-level wind field to
support rotating storms this evening, with a few of these storms
approaching severe limits at times. These storms were mainly
confined to northern portions of our area, where model analyses
suggest effective storm relative helicity values of around 200 and
effective shear on the order of 30 kt. While these values are
forecast to decrease with time, there remains a low-end concern
that a few storms overnight may still achieve strong or possibly
low-end severe status. The genesis region for these storms as
depicted by the latest high resolution model guidance is along the
Gulf coast along and ahead of the moisture gradient in
association with a pre-frontal trough. The storms would then
advance E/NE-ward into our area overnight. There remains some
question as to the coverage and intensity of the storms, but the
primary severe hazards (if realized) would be an isolated damaging
wind gust and/or brief tornado. This threat should be ending by
the early morning hours with quieter weather expected on Sunday.
Warm and muggy conditions will continue with temperatures
approaching record warm minimum and maximum values.
&&
.AVIATION(00Z TAFS)...
Prevailing VFR through the TAF period. Small shower chances into
Sunday but too low for mention (outside of APF/PBI). SSE winds
this evening should shift more towards the SSW by tomorrow
morning, possibly shifting back to the SSE by tomorrow afternoon.
Low confidence in the afternoon wind shift, so kept the winds SSW
for now.
&&
.PREV DISCUSSION... (Issued 333 PM EDT Sat Oct 19 2019)
Discussion...
Short Term (Tonight-Sunday): the latest forecast for Post-
tropical cyclone Nestor show the associated stratiform canopy
moving across SoFlo, which had a noticeable hindering effect to
the daytime heating cycle earlier today. Showers and thunderstorm
activity will gradually diminish tonight as the remnants of Nestor
continue to pull NE and away from the Florida peninsula. But
there is still enough dynamic support for any storm that forms to
become strong tonight with model and upper air sounding data
depicting SRH 0-1km around 100, PWATs close to 2 inches, and
plenty of upper lvl divergence for adequate ts-top ventilation.
SPC has portions of SoFlo in a marginal risk for severe weather,
mainly Glades, Hendry and northern Collier counties, where the
stronger convection associated with the frontal boundary draped
across central Florida has been observed on radar. However, the
limiting factor continues to be having an effective lifting
mechanism for convection to reach the better dynamics aloft.
Therefore, will keep the inherited trend of decreasing POPs/Wx
this evening and into the overnight hours with mainly scattered
coverage across the area.
Brief heavy downpours could still bring localized flooding at
times, with also a marginal risk of excessive rainfall continuing
this evening.
As the remnants of Nestor move away from the region on Sunday, the
aforementioned frontal boundary will stall over southern Florida. The
leftover moisture lingering across soFlo will combine with returning
daytime heating for some convection to develop Sunday during the
early afternoon hours. The moist airmass will also contribute to
warmer temps on Sunday with highs climbing back to near 90.
Long Term (Monday-Saturday): General benign weather conditions
will return early next week with high pressure establishing in the
wake of Nestor, and with the frontal boundary over the region
finally lifting and dissipating.
Long range model solutions suggest increasing rain chances
for the middle of the week as the next cold front approaches the
area. This front should stall somewhere over extreme SoFlo or even
into the Keys. Slightly cooler temperatures are possible by
week`s end along with shower chances given the front in the
vicinity.
Temperatures remain close to seasonal values or slightly warmer
with afternoon highs in the upper 80s to around 90.
Marine...
A Small Craft Advisory remains in effect for all Gulf waters
through late tonight due to elevated winds and seas associated
with Nestor. Also, Cautionary conditions are possible over the
Atlantic waters and Lake Okeechobee. Showers and thunderstorms,
some potentially strong, will continue to develop at times
tonight, and possibly through Sunday. Seas in the Gulf will be
slow to subside on Sunday as residual swells from Nestor continue
to move toward the coast.
Beach Forecast...
Hazardous beach conditions continue along the Gulf coast as Nestor
moves across the Florida Panhandle tonight. There is a high risk
for Rip Currents through Sunday, with minor coastal flooding
possible through the first half of Sunday due to onshore flow and
increased swells.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 89 76 88 / 40 30 20 20
Fort Lauderdale 79 89 78 88 / 20 30 10 20
Miami 78 89 77 88 / 20 20 0 20
Naples 77 88 75 89 / 80 50 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Sunday evening for FLZ069.
AM...None.
GM...Small Craft Advisory until 2 AM EDT Sunday for GMZ656-657-676.
&&
$$
Update/Aviation...SPM
Tonight/Sunday and Marine/Beaches...AR
Sunday Night through Saturday...AR
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Sunday)
Issued at 320 PM CDT Sat Oct 19 2019
For tonight and Sunday morning, dry air over the area and a lack
of forcing is expected to keep dry weather over the area. The RAP
and NAM forecast soundings show some potential for radiational fog
with the boundary layer decoupling and becoming saturated after
06Z. With dewpoints holding in at around 50 across east central
KS. think probability for fog formation is increasing and have
included a mention of fog in the forecast. Considered a dense fog
advisory for parts of eastern KS, but models have the pressure
gradient increasing overnight and hint at some wind developing
before sunrise. The NAM even suggests any fog lifts into a stratus
deck. So confidence in dense fog is not as high and will let
later shifts monitor trends for a dense fog advisory. Lows tonight
are expected to fall into the 40s.
The next frontal boundary is forecast to move into the area Sunday
evening as an upper low closes off and deepens to the north of the
area over NEB and SD. There continues to be some variability with
the track of the system. This impacts how much moisture may move
north ahead of the boundary and the NAM has trended with higher
elevated instability across east central KS. So there remains a
potential for severe storms given the deep layer shear. Although
much of the guidance has low level winds a little more veered with
the better moisture shifted east into MO. If the front is more
progressive, there may only be a few hours in the late afternoon or
early evening for thunderstorm development. Otherwise think precip
chances will push off to the east after midnight with the front
pushing through and dry air increasing. Have trended highs Sunday
cooler be a degree or two. It is looking like mid level clouds could
be on the increase early in the day. So even if there is limited fog
and stratus in the morning, insolation could be limited and make it
hard for temps to reach the lower 70s.
.LONG TERM...(Monday through Saturday)
Issued at 320 PM CDT Sat Oct 19 2019
Monday and Tuesday continue to look dry as the closed storm
system slowly lifts into the Upper Midwest. This should leave a
dry westerly flow over the central plains with precip unlikely.
Monday could be a blustery day as a northwest wind gusts while
some cold air moves in as well. Highs are forecast to only make it
to around 60. Some moderation is anticipated for Tuesday with
winds becoming southwesterly with good insolation.
The next weather system is likely to affect the area Wednesday night
and through the day Thursday. Models are starting to come into
better agreement with a cold front setting up to the southeast of
the forecast area while a positively tilted upper trough deepens
over the southern Rockies on Thursday. This would favor pieces of
energy to lift out from the base of the upper trough along the
frontal boundary while moisture advects north into the boundary.
There remains some uncertainty as the Canadian solution is a little
stronger with a surface ridge and pushes the boundary further south
with more dry air limiting precip chances for us. Also the GFS prog
shows northerly low level winds persisting north of the boundary
with the potential for dry air to undercut any overrunning across
the forecast area. Nevertheless there looks to be a chance for
mainly cold rain at this point. Although forecast soundings from the
GFS are not to far off from being cool enough for some wet
snowflakes to fall with surface temps in the +1C to +3C range. Have
trended highs for Thursday down to around 50 thinking clouds and a
north wind will limit warming. This may still be to warm if we do
see a stratiform rain for much of the day as the GFS/ECMWF
advertises. Would like to see better agreement from the models in
temp profiles as well before getting to excited for snow chances as
the ECMWF and Canadian don`t have as much cold as the GFS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 624 PM CDT Sat Oct 19 2019
VFR conditions are expected through 07Z with mist and fog
developing after 08Z, especially at TOP and FOE where mvfr to lifr
vsbys are possible between 10Z and 13Z. Fog may lift into a lifr
cig at TOP and FOE, but held off for this issuance. MHK may see
some river valley fog reducing vsbys to mvfr after 07Z to 11Z
when winds are expected to increase. VFR expected after 13Z with
increasing southeast to south winds around 12kts, increasing to
near 14 kts after 18Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Wolters
SHORT TERM...Wolters
LONG TERM...Wolters
AVIATION...53
Area Forecast Discussion
National Weather Service Tulsa OK
838 PM CDT Sat Oct 19 2019
.DISCUSSION...
The main challenge in the short term will be fog potential and low
temps.
Low VFR cigs developed this afternoon over far eastern OK and
western AR and have been slow to erode this evening. If these
clouds hold on, fog potential would be greatly reduced. The HRRR
has trended less aggressive with the fog thru the evening,
especially over NW AR, which has me suspicious. Feel more
confident we will have fog development west of the clouds across
portions of NE OK, and the HRRR still suggests some fog here. One
would think that west of the cloud deck there will be favorable
radiational cooling conditions. This, combined with the fact that
dry air advection from the west has stopped, leads me to believe
there will be fog. I will leave the going fog forecast intact,
showing some faith that the HRRR will be right with the eventual
erosion of the cloud deck over western AR. Confidence isn`t high
enough to issue any headlines attm however. I also made some
tweaks to overnight lows but no major changes.
Lacy
&&
.PREV DISCUSSION... /Issued 642 PM CDT Sat Oct 19 2019/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Mostly clear to a few low end VFR conditions should continue into
the overnight hours across much of Eastern Oklahoma....while
broken/overcast low end VFR holds over Northwest Arkansas through
the evening. Overnight tonight...ceilings are forecast to lower
across Northwest Arkansas...with widespread LIFR/IFR ceilings and
visibilities possible late tonight into Sunday morning. Some of
these conditions looks to reach Eastern Oklahoma TAF sites and
will continue tempo groups for timing. During the day Sunday...the
fog/low stratus clouds should lift and dissipate by late
morning/early afternoon with southerly winds and few/scattered
high clouds for the afternoon hours.
PREV DISCUSSION... /Issued 343 PM CDT Sat Oct 19 2019/
DISCUSSION...
The main forecast concerns will be fog potential tonight, followed
by severe weather potential with a strong upper storm system and
cold front Sunday night into early Monday. Rain/storm chances with
another storm system and front for the latter half of next week is
also worth mentioning.
An impulse which brought the showers and a few storms last night
into this morning has lifted off to the northeast. At the surface,
a weak cool front is sliding east across the region in the wake of
the upper disturbance. Moisture is increasing across the region,
especially down over the Arklatex. While some drier air is trying
to advect in from the west, models suggest this will stop after
sunset as winds go light beneath the surface ridge. Clearing
skies, light winds and the higher dewpoints all say radiational
fog potential tonight. The NAM and HRRR guidance break out
widespread dense fog across SW MO, SE KS and down into NW AR and
NE OK after midnight tonight. The NAM would suggest that some fog
potential will extend south of there as well, into SE OK and W
Central AR. Inserted areas of dense fog, with patchy fog mention
in the south where there is more uncertainty.
Now to the meat of this forecast. A strong PV max currently over
the Pacific Northwest, on the nose of a potent cross-Pacific jet,
will dive southeast and then east across the northern and central
Plains Sunday night. At the surface, a cold front will advance
east/southeast across the region. There are some hints in the data
of a frontal low developing on the front near the nose of the mid
level jet streak in the base of the parent upper low/trough across
south central OK then tracking across southeast OK. Moisture
recovery ahead of the front remains a big question, as most data,
including the GFS and HREF, suggests that the true warm sector
will not extend much farther north than the Red River. The NAM is
by far the most aggressive with northward advancement of warm
sector, and is an outlier at this point. As such, the magnitude
of this severe event remains in doubt. Showers and storms will
likely begin initiating near the frontal low/triple point with
coverage gradually expanding along the front with time. Kinematic
fields will be easily sufficient to support rotating/organized
storms. The initial development could become supercellular, though
increasingly elevated the farther north you go, with a large hail
and possibly a wind threat. Storms down near the Red River, ie.
Pushmataha and Choctaw counties, will have the best chance of
being near surface-based and would be capable of producing large
hail, damaging winds and a tornado or two. The convective mode
should trend toward linear with time along the advancing front. The
front should clear the region between 4 and 7 AM, ending the
severe weather threat.
Another storm system and front will affect the region beginning
Wednesday night and continuing potentially into Friday. The ECMWF
has gone back and forth regarding closed low development within
the diving PV max/shortwave trough during this time frame. The GFS
remains progressive and has been more consistent. What is of
greatest confidence is rain potential with moisture returning and
interacting with the front ahead of the approaching system
Thursday. Raised PoPs above blended guidance as a result, mainly
Wednesday night and Thursday. Instability will be limited and
confined mainly to the south for this event as it looks now. Rain
chances will taper off by the weekend, though how quickly this
occurs is still a bit uncertain.
Lacy
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 48 78 50 68 / 0 0 80 0
FSM 53 81 55 70 / 0 0 90 10
MLC 49 80 53 69 / 0 0 90 0
BVO 42 77 46 67 / 0 0 90 0
FYV 48 75 51 63 / 10 0 90 10
BYV 50 76 53 64 / 20 0 90 10
MKO 48 78 50 67 / 0 0 80 0
MIO 46 75 48 64 / 0 0 80 0
F10 48 80 51 68 / 0 0 90 0
HHW 53 81 56 70 / 0 0 90 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...30