Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/03/17
Area Forecast Discussion
National Weather Service Binghamton NY
743 PM EDT Thu Nov 2 2017
Conditions will be primarily dry and warm tonight. A cold front
will then cross the region Friday with a few showers, followed
by cooler air. The best chance of rain will be in central New
York. Saturday will be dry and seasonable. Rain showers will
return Saturday night.
.NEAR TERM /THROUGH FRIDAY NIGHT/...
730 pm update...
Only minor changes made to the forecast. Moved ahead the start
time of the initial band of rain expected to move in late
tonight/Friday morning...and increased expected rain amounts by
less than a tenth of an inch...per the latest runs of the HRRR
3 pm update...
Last bit of showers exiting Otsego County NY. Some breaks in
the clouds have pushed temperatures into the mid and upper 60s
this afternoon. Some showers still possible in Oneida County
through the evening.
Late tonight showers return with and behind a cold front
dropping southeast into and through the area in the morning.
Showers will be mostly in central NY where the best support is
for lift. Moisture will not be deep. The upper level flow dips a
little but for the most part it will be zonal this period. The
showers end in the afternoon from northwest to southeast as high
pressure builds in from the upper Great Lakes.
Temperatures drop little tonight into the low and mid 50s with
the southerly flow. Friday a nondiurnal trend with temperatures
in NY moving little with the early fropa. In NEPA temperatures
have time to get well into the 60s before the front. Behind the
front temperatures drop into the 40s in NY and 50s in PA. Lows
Friday night in the low to mid 30s with partly cloudy skies and
a much drier air mass.
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
For Saturday, high pressure covers the region in the morning as
the next system rapidly approaches from the Great Lakes and
midwest. Strong warm air advection develops during the day as
the high slides off the coast and NY and PA get into a deep
southerly flow. Models all show a short wave riding northeast
across the Ohio Valley to Eastern Great Lakes late Saturday and
Saturday night. A strong low-level jet will form in response to
this wave and will accelerate as it moves through NY and PA
late Saturday and especially Saturday night. This low-level jet
will lead to enhanced isentropic lift / warm air advection and
moisture transport into our area. Hence, a steady rain will
break out across all of central NY and northeast PA Saturday
night and early Sunday. Later on Sunday the rain will taper to
scattered showers as the best lift and warm air advection shifts
northeast of the region.
Then for Sunday night, another short wave associated with the
cold front shifts east and will spread showers into western NY
so have likely POPs in our western counties and chance POPs for
rain showers rest of forecast area.
.LONG TERM /MONDAY THROUGH THURSDAY/...
For Monday, models are in agreement that the cold front with
associated rain showers will cross the region with likely to
categorical POPs all areas. For Monday night, Tuesday, Tuesday
night and Wednesday we will continue the chance for showers
which could mix with snow showers Tuesday night and early
Wednesday as a west to southwest flow remains over the area with
various short waves moving through. Colder air moving into the
region could lead to a little mixed rain and snow showers
Tuesday night and Wednesday. Accumulations will be minimal.
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR conditions will continue this evening. Still expecting a
cold front to move in late tonight and Friday morning with
steady rain showers likely. Ahead of the front ceilings will
lower to MVFR. Will see visibilities lower to MVFR and cigs drop
to fuel alternate required around 11-13Z. In NY ceilings will
drop to IFR in the rain at times. The rain will taper off after
14-17Z with MVFR cigs continuing through midday and becoming VFR
by the mid to late afternoon hours.
In PA, AVP will see upslope flow ahead of the front, which will
allow cigs and vsbys to fall to MVFR around 08z. Ceilings stay
MVFR behind the front but visibilities should rise with no
significant restrictive rain expected.
South winds 5 to 10 kts this evening will shift to the
southwest Friday morning then west to northwest at 10 kts in
low level wind shear in NY with a SSW jet at 35 to 40 kts at 2k
Friday night and Saturday...Mainly VFR.
Saturday night through Tuesday...Chance of flight restrictions
with showers as fronts/disturbances pass through the region.
Area Forecast Discussion
National Weather Service Denver/Boulder CO
926 PM MDT Thu Nov 2 2017
Issued at 904 PM MDT Thu Nov 2 2017
Model show a fair amount low level moisture across the northeast
plains late tonight and early Friday morning. As a result, areas
of stratus but will also add patchy fog to the grids. Otherwise
only minor adjustments planned at this time.
.SHORT TERM...(This evening through Friday)
Issued at 345 PM MDT Thu Nov 2 2017
Low stratus and fog will continue to dissipate through the late
afternoon. Temperatures will lag on the plains with highs more in
the 40s to lower 50s. Altered daytime temps with a few degrees
shaved off of MOS guidance to account for weak diurnal heating.
GOES-16 water vapor shows upper jet over Wyoming extending south
with the anti-cyclonic region helping bring enough mountain-top
stability for a small mountain wave for the late afternoon and
early evening. The jet will transition to the north as an upper
trough pushes toward the west coast bringing increased SW flow
over the Great Basin. At the surface SE flow will continue into
the early evening hours helping to keep moderate levels of
moisture at the surface. Lows will get back into the lower 30s
with clearing overnight creating some low stratus/fog formation in
the early hours on Friday...especially over the SE counties of
Elbert and Lincoln. Some areas in South Denver and the Palmer
Divide area might be an exception due to winds changing to the SW
through the morning that will help bring drier air and keep
stratus at bay. Temperatures will be warmer than today with highs
reaching into the mid 60s.
.LONG TERM...(Friday night through Thursday)
Issued at 345 PM MDT Thu Nov 2 2017
Westerly flow aloft will continue through the middle of next week.
A short wave will move north of Colorado Saturday night, then
another wave which may be stronger will move over the state about
Moisture and winds will increase ahead of the first wave Saturday.
This will bring orographic snow to the mountains. Initially the
flow will be more southwesterly with relatively warm temperatures.
The snow level will be around 9000 feet Saturday, but should fall
at least a thousand feet by Sunday morning. Warm temperatures may
limit accumulation a bit in areas below 9000 feet, but at higher
elevations there should be significant snowfall over a 24-36 hour
period as there will be a deep moist layer and 25-30 knots of flow
at ridgetop. I would not be surprised to see a foot of snow in
areas favored in west to southwest flow, especially over the
northern portion of our mountains where there may be a bit more
lift and instability. Given the strength of the wind and some
synoptic scale lift, some of the snow should spill over into the
foothills mainly north of I-70. Temperatures will limit
accumulation though, and the first half of the event may be mainly
rain in the foothills. On the plains in this period it will be
warm and breezy ahead of the wave on Saturday, then a cold front
will move in late Saturday. Any showers will likely be limited to
areas near the northern border. Sunday will have cooler
temperatures, and maybe some stratus in the morning.
Monday is a bit of a break, though there will still be some
moisture to produce some light mountain showers. It will still be
cool on the plains.
Still varying solutions on the next wave, somewhere between an
open trough bringing a quick shot of showers Monday night into
Tuesday, and a stronger wave with a better chance of widespread
precip Tuesday into Wednesday. Pretty good chance of snow again in
the mountains, the stronger solutions would give a chance of rain
and maybe a little snow over the plains while the weaker ones
would just be a quick chance of showers Monday night. We will
continue a compromise with a low chance of showers Monday night
through Tuesday night. After some lingering mountain showers,
there may be a bit more moisture coming into the mountains
Wednesday or Thursday.
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 904 PM MDT Thu Nov 2 2017
Latest HRRR runs maintains a weak north/northeasterly flow this
evening then transitions to a light west/northwest or variable
component after 09z. Could see some patchy fog overnight for brief
period of IFR restrictions fm 11z-15z. Otherwise VFR conditions
with no restrictions.
Area Forecast Discussion...Updated
National Weather Service Billings MT
817 PM MDT Thu Nov 2 2017
Bands of light snow continue to develop over south central
Montana and drift northeast. This being caused by isentropic
ascent and jet forcing, along with some weak low level upslope
flow. GFS was not handling this well at all, and the HRRR wants to
constantly kill the precip off, then redevelop it late tonight.
Adjusted PoPs already for the evening earlier, and made another
update to raise PoPs again for the overnight hours. Although
isentropic lift and upslope flow weakens overnight, jet forcing
lifts north, but not enough to decrease light snow chances in
Billings overnight, so kept light snow going. Snow should not
amount to much, with the heavier amounts along the western
foothills and locations north of Billings overnight. TWH
.SHORT TERM...valid for Fri and Sat...
Areas of light snow were seen on radar moving N into the forecast
area. The snow was being generated by isentropic lift. The models
were in good agreement with the synoptic pattern through Saturday
night, but differed with QPF amounts. Tonight, the right-rear
quadrant of an upper jet will bring divergence into the western
zones, while isentropic ascent continues over the area. These
factors will bring the likelihood of snow W of KBIL with lesser
chances elsewhere. Will begin a Winter Storm Warning for the
western mountains at 06Z tonight. The jet divergence will move
into the north central part of the area by 18Z Friday and
isentropic lift continues, as a warm front pushes N into SE MT.
The best chances for snow will continue W of KBIL. Rain will mix
with snow in the afternoon from KLVM to just SE of KBIL to N
Rosebud County S. The GEFS plumes continue to show a threat of
freezing rain and sleet in KBIL, but will continue to leave this
out as GFS Bufkit soundings do not look convincing enough to add
this precipitation. Periods of Q-vector convergence will move
through the area on Friday and Friday night. A cold front pushes S
into the area Fri. night with a frontogenesis band that moves
quickly S. Jet divergence continues over the west, adding to the
lift. Again, highest precipitation chances will be W of KBIL with
decent chances to the N as well. Frontogenesis moves S of the area
on Saturday with more jet divergence over the W in the morning
that shifts E during the day. A shortwave will push through the
area Sat. through Sat. evening. Pushed the high PoPs southward a
bit faster on Saturday per the models, and left a chance over the
area Sat. night.
Noted the QPF was higher on the ECMWF than on the GFS through the
event, but the W was targeted with the highest snow chances on
both models. Thus ran the Winter Storm Warning for the mountains
through 13Z Sunday. Also will issue a Winter Storm Watch for
Judith Gap S through the foothills, and W through Park County,
including the Paradise Valley, for 12Z Fri. through 13Z Sunday.
May eventually need Advisories E of the Watch area. Arthur
.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...
Snowy and cold pattern will continue through the weekend into the
beginning of next week. Models are in good agreement to start the
extended but diverge somewhat by the end of next week.
The Friday/Saturday snow will be winding down by Sunday morning
as the disturbance and upper forcing move east of the forecast
area. There will continue to be some lingering light snow or snow
showers during the morning, but the precip will be ending from
north to south during the morning/early afternoon hours. Morning
lows Sunday will be quite cold with teens common and highs Sunday
will only be in the lower to middle 20s for most locations.
By Monday, another upper low and trough over the Pacific
northwest slide southeast across Idaho during the morning and
afternoon bringing another quick shot of snow to the forecast area
with the best chances along and south of KLVM-KBIL-Hardin line.
Highs Monday will continue to be well below normal with readings
only in the 20s.
Models try to build some ridging along with some downslope flow
across the area Tuesday into Thursday. This would bring a break in
the precipitation along with a slight warming trend with
temperatures back into the 30s to possibly lower 40s, but these
readings would still be below normal for this time of year.
Areas of light snow can be expected through the overnight hours
and through Friday morning. These will mainly be along and west
of a Roundup-Billings-Sheridan line. MVFR/IFR conditions will
prevail across these areas due to low ceilings and/or lower
visibilities in areas of snow. Isolated regions of LIFR are
possible through the night as well. East of this line, cloudy
skies with isolated snow showers are possible with MVFR conditions
prevailing mainly due to low ceilings. All mountains will be
obscured through the TAF period. Some improvement in conditions to
VFR/MVFR is possible after 18z tomorrow as a weak warm front lifts
.PRELIMINARY POINT TEMP/POPS...
Fri Sat Sun Mon Tue Wed Thu
BIL 026/036 025/032 018/027 014/025 015/033 019/040 023/043
74/J 58/S 53/S 34/S 31/U 00/N 11/B
LVM 026/038 024/034 018/031 017/028 015/036 020/042 026/045
77/W 97/S 43/S 44/S 31/U 01/N 22/W
HDN 026/042 025/035 018/030 014/028 015/037 018/044 021/046
63/W 37/S 53/S 24/S 21/U 00/B 11/B
MLS 027/041 027/033 017/027 013/023 014/034 017/039 021/042
33/W 45/S 32/S 24/S 21/U 00/U 11/B
4BQ 028/044 029/038 021/030 016/028 017/037 021/043 023/046
32/W 24/O 52/S 23/S 22/J 00/U 11/B
BHK 025/035 026/034 016/027 012/024 013/033 018/039 021/040
33/J 34/S 42/S 13/S 21/B 00/U 01/B
SHR 025/044 025/037 018/032 015/030 014/037 018/045 021/046
42/W 17/O 73/S 13/S 21/B 00/U 11/B
MT...Winter Storm Watch in effect from 6 AM MDT Friday through
late Saturday night FOR ZONES 28-40-41-56-63>66.
Winter Storm Warning in effect from midnight MDT tonight to 6
AM MST Sunday FOR ZONES 67-68.
Area Forecast Discussion
National Weather Service Charleston SC
1006 PM EDT Thu Nov 2 2017
High pressure along with warm temperatures and dry conditions
will prevail through early next week. A cold front is expected
to push through the region around Wednesday, followed by high
pressure through late next week.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Dry through tonight with broad surface high pressure in place.
There could be some higher clouds as a shortwave moves through
aloft but generally clear skies and calm winds will promote
some fog late tonight as suggested by MOS, NAM, RAP and SREF
guidance. Can`t rule out the fog getting dense in spots similar
to last night but overall the threat appears low given limited
low-level moisture. Low temps will be in the mid to upper 50s,
except lower 60s close to the coast.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Friday through Sunday: A series of disturbances will move through
the southeast Friday and Saturday before ridging builds back in on
Sunday. These disturbances could bring rounds of enhanced
cloudiness, but with such a dry air mass in place there is little to
no support for precipitation. At the surface, weak high pressure on
Friday will dissipate as a backdoor cold front attempts to approach
from the north early Saturday. Then high pressure will then become
more prominent again on Sunday. Overall, no change to the previous
forecast. Land areas are expected to remain dry, with only slight
chance PoP`s at times over the weekend across the coastal waters as
a subtle coastal trough develops. A more important note is the warm
temperatures through the weekend. Highs each day are expected to be
in the 79-83 degree range for most locations, with some mid 80s
possible across interior southeast Georgia. Overnight lows will be
mild, ranging in the upper 50s to low 60s. Finally, we could also
see rounds of fog early each morning through the weekend. Fog has
not been added to the forecast as of yet, but is certainly worth
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
This period will begin with unseasonably warm conditions for early
November. Deep layered high pressure will reside over the region
Monday then will shift south ahead of an approaching upper
trough/associated surface cold front. Temperatures in the lower/mid
80s Monday could increase to record/near record levels in the
mid/upper 80s Tuesday as offshore flow develops. A cold front is
then expected to cross the area around midweek, but confidence is
low regarding timing and associated POPs. The latest forecast
indicates above-normal temperatures and low POPs Wednesday followed
by more seasonable temperatures Thursday.
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Maintained VFR through 00Z Sat. Moderate chance for some fog
across the area late tonight toward 12Z given decent radiational
cooling conditions but confidence too low of any significant impacts
at the terminals to mention at this time.
Extended Aviation Outlook: Expect VFR conditions to prevail. There
is a small chance for some flight restrictions in late night/early
morning ground fog each day.
Conditions across the local waters will generally be quiet
through the weekend and into early next week. High pressure will
be the main feature during this period, though it will evolve
with time as one weak high center dissipates this weekend and
gets replaced by another thereafter. Northeast flow will be the
prevailing flow through much of the period, then shifting to
more southerly and then southwesterly by Tuesday. Wind speeds
through the period are expected to top out in the 15 knot range,
strongest Saturday and Sunday. Seas are expected to be in the
2-4 foot range and no Small Craft Advisories are anticipated.
The November 4 full moon/spring tide and subsequent November 6
Perigee will combine to produce elevated astronomical tides this
weekend into the middle of next week. The latest guidance
indicates stronger northeast winds which could contribute to
elevated tide levels Saturday through Sunday. Thus, Coastal
Flood Advisories for minor coastal flooding could be needed at
least around the times of the morning high tides this weekend.
Then, even as astronomical factors continue to support elevated
tides into the middle of next week, wind direction/speed will
change and will contribute less to tide levels as compared with
the weekend. Thus, while minor coastal flooding could still
occur around the times of the morning high tides during the
first half of next week, the probability for Coastal Flood
Advisory conditions will decrease.
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1004 PM CDT Thu Nov 2 2017
Minor tweaks to both temps and dew points tonight, to account for
trends in observations. Overnight low temperatures should fall into
the low 70s across SE TX. Patchy fog will also be a possibility
across much of the region based off short term guidance visibility
probabilities, and higher dew points specifically along the coast.
These misty conditions may result in an occasional drizzle in the
early morning hours starting around 09Z, as indicated in the HRRR
short term guidance. Coverage becomes more isolated across SE TX
by the late morning hours, and therefore still holding on to a 20%
PoP over much of the forecast area for Friday. Removed isolated
thunderstorms from the forecast for the late morning hours based
on the forecast soundings which show a decent cap around 850 mb.
.PREV DISCUSSION... /ISSUED 646 PM CDT Thu Nov 2 2017/
VFR conditions are expected to transition to MVFR by 06-09Z
overnight with CLL/UTS/CXO experiencing drops to IFR. Expect MVFR
ceilings to persist through the morning, lifting above FL030 after
18Z. Patchy MVFR fog will be possible again overnight outside of
the Houston terminals with deep moisture along the coast resulting
in MVFR visibility reductions at Galveston from haze/mist.
Isolated showers will be possible mid to late morning through the
afternoon hours near the terminals but anticipated coverage is too
low to mention in the TAF attm. Southerly winds 10 knots or less
are expected through the period.
PREV DISCUSSION... /ISSUED 313 PM CDT Thu Nov 2 2017/
An upper level high pressure area over northern Mexico will keep
a southwesterly flow pattern in the mid and upper levels over
Southeast Texas through the weekend and very warm temperatures
for this time of the year are expected.
For the late night and early morning periods over at least the
next couple of days, patchy fog could form. Isolated rain chances
are possible on Friday as an upper level shortwave trough moves
across the Southern Plains. Even these isolated rain chances will
diminish to just the far southeastern areas on Saturday and to
below 20 percent on Sunday through Tuesday.
There is the possibility of cooler temperatures and better chances
of rain by the middle of next week. This will depend upon how far
south a cold front moves from the Red River Valley. The GFS keeps
the front mainly north of the forecast area while the ECMWF pushes
the front through to the coast during the day on Wednesday. Given
the westerly upper flow pattern at that time, the front may only
briefly move that far south before pushing back inland.
High pressure over the eastern United States and lower pressure over
West Texas and the Plains will maintain a moderate southerly flow
until the middle of next week. 33
Temperatures could possibly reach to near the record highs over
the next few days. The following table lists the record high
temperatures for the major climate sites in the NWS
Houston/Galveston forecast area:
Houston Hobby Arpt Galveston College Stn
Date Rec/Date Rec/Date Rec/Date Rec/Date
Nov 3rd 88/2016 90/1973 85/1886 88/1948
Nov 4th 89/1988 88/1988 85/1988 90/1948
Nov 5th 88/1963 87/2005 83/1886 92/1891
Nov 6th 88/1963 88/1963 83/2005 88/1931
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 70 85 69 85 68 / 10 20 10 10 10
Houston (IAH) 72 85 70 85 71 / 10 20 10 10 10
Galveston (GLS) 75 81 73 82 73 / 10 20 10 10 10
Area Forecast Discussion
National Weather Service Wilmington OH
923 PM EDT Thu Nov 2 2017
A cold front will push through from the west tonight, bringing
showers and isolated thunderstorms. Drier weather will follow on
Friday with high pressure building to the north. A few showers may
develop on Saturday when a warm front is forecast to lift north
across the area. Showers and thunderstorms are expected late
Sunday along another cold front.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Surface analysis shows that the cold front is currently located
roughly from Pontiac MI to Danville IL, continuing to work its
way into the region. As has been expected, convection has
developed in broken bands along and just ahead of the front.
Though probably not purely surface-based, there has been enough
instability for thunder to develop. Well ahead of the cold
front, within a regime of continual boundary-layer theta-e
advection, a rippling convergent band of showers has entered the
ILN CWA, and is now becoming somewhat convective in the Dayton
area. This appears to be forced further aloft -- tracking the
feature on radar, it is evident that the overall source of lift
is moving SE, while individual echoes are moving ENE with the
The 00Z KILN sounding is actually no more moist than the 12Z
flight, but the environment will continue to moisten ahead of
the front, with precipitable water values eventually reaching
into the 1.25"-1.50" range. The evening sounding also indicated
a strong cap near 800mb, which will erode as the lower levels
saturate and the front approaches.
SPC mesoanalysis and HRRR soundings show that instability will
continue to be narrow/weak but present, even into the overnight
hours. PoPs were re-focused a little bit based on HRRR timing,
and thunder was included for the entire CWA for a few hours near
frontal passage. T/Td grids were also tightened up a bit to
follow current trends.
Previous discussion >
Area is under a mild southerly flow in the warm sector. Weather
is dry to start though clouds persist in a few saturated
After dry conditions continue into this evening, a
strengthening cold front to the west will be moving through.
Showers will develop and spread from northwest to southeast with
the front, warranting continuation of categorical pops. There
will also be a slight chance for thunderstorms in an environment
containing up to 500 j/kg CAPE aloft.
With the southerly flow persisting for much of the night,
overnight lows will stay above normal, ranging from around 50
northwest up to the lower 60s southeast.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Cold front will be positioned near the southeast corner of the
FA Friday morning. While the progression of the front slows as
it becomes more parallel to the mid level flow, lingering
showers will diminish during the morning and then end by mid
afternoon, leaving dry weather late Friday afternoon into
Friday night when the front will lie south of the area. Later
Friday night, the front will return north as a warm front,
producing a chance of showers again.
Highs on Friday will not rise too much due to cold advection on
northerly behind the front. However, highs ranging from the mid
50s north up to the low 60s south will stay a bit above normal.
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Aforementioned frontal boundary will be moving north as a warm front
on Saturday. Moist ascent (WAA/isentropic lift) will already be
ongoing, bringing a chance of showers to the region during the
morning hours. An embedded s/wv is expected to pivot from the
central Plains into the Great Lakes during the day. Best overall
forcing still looks to be to our west/northwest. However, there are
some hints that showers may become a little more numerous as the
warm front moves through our northern zones. Confidence is not quite
there yet for likely PoPs, so have given all locations a high chance
PoP of 50 percent. Temperatures will warm into the 60s region wide.
The s/wv and warm front will lift north of the region Saturday
night. Will continue with a chance of showers, but this chance
should decrease from south to north overnight. Lows will not fall
that much, ranging from the upper 50s to the lower 60s.
Focus for Sunday into Sunday night will be on a mid level trough to
traverse southern Canada/the upper Midwest/northern Great Lakes. A
cold front will accompany this system, which is still forecast to
move southeast into the region Sunday night. Initially, we should be
warm sectored for most of the day on Sunday. There could be a low
chance of showers, mainly across our northwest in the WAA pattern.
It will become breezy as south winds gust between 20 to 30 mph
during the afternoon. Despite considerable clouds, this WAA pattern
will boost temperatures into the lower and perhaps mid 70s. For
Sunday night, models are in fairly good agreement on frontal timing
and a weak surface low to ripple northeast through the Great Lakes.
Instability ahead of the front will increase due to warm, moist air
in the low levels combing with steepening mid level lapse rates as
the front approaches. This setup will provide for MLCAPEs to be
close to 1000 J/KG early on across our region, with a gradual
overall decreasing instability trend as the night progresses
(diurnal cycle). Low level convergent forcing is expected to be
decent along and ahead of the front which will result in the
likelihood of showers and embedded thunderstorms overnight. There is
some concern for a few storms to be strong or marginally severe,
particularly across our far northwest early on. The pros for
marginal and/or a small severe threat are the marginal instability
and sufficient deep layered shear for storm organization. The
precipitation will likely end up forming into line segments.
However,the threat for a decent QLCS doesn`t seem to be there given
slow frontal movement, weak surface low pushing quickly away to the
northeast, and an unfavorable 0-3 km shear vector angle to the
potential orientation of the convective line. As such, do not think
the severe threat will be as expansive as currently depicted in the
SPC day 4 product and have opted to keep the low hazard probability
threat in the HWO at this time. If a threat should materialize, it
would be mainly due to wind. Lows Sunday night will remain mild,
ranging from the mid 50s northwest to the lower 60s southeast.
On Monday, models push the front southeast through the region. There
will likely be a decrease in the precipitation threat by afternoon
as it shifts to our southeast. Temperatures will not warm too much
from morning lows.
For Monday night into Wednesday, models continue to struggle with
the mid level flow pattern and subsequent embedded s/wvs and
associated ripples that may develop along stalled boundary near our
south. As such, the threat for precipitation will exist, especially
south, but had to broad brush the extended given timing, position,
and strength issues among the models.
By Thursday, models suggest that surface high pressure may finally
build into the region, ending the precipitation threat.
Temperatures for the remainder of the extended will exhibit a
cooling trend to values below normal for early November.
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
VFR conditions will continue for another few hours, but MVFR
ceilings will advance into the region later this evening. A few
light showers will also be possible.
Most of the focus for this forecast is with the cold front
moving through the region overnight. Ahead of the front, there
will be a period of rain, with some embedded heavier showers
possible. There is a slight chance of thunderstorms developing
as well, but with too low a probability to include for any of
the TAF sites. Nonetheless, the heavier showers could produce
brief IFR conditions. Eventually, as the front approaches, IFR
ceilings are expected at all of the TAF sites anyway. There will
be a sharp wind shift from the SSW to the NNW, and some gusts in
the 15-20 knot range will be possible as this occurs.
Ceilings will gradually improve on Friday, though MVFR ceilings
may persist into the late morning or early afternoon, especially
at the Cincinnati TAF sites.
OUTLOOK...MVFR conditions are possible at times from Saturday
afternoon through Monday. There will also be a chance of
thunderstorms late Sunday afternoon through early Monday
Area Forecast Discussion
National Weather Service Jackson MS
917 PM CDT Thu Nov 2 2017
Updated for evening discussion.
Expect isolated shower activity overnight. Patchy fog will be
possible late, especially across the southeast. Lows temperatures
tonight will be in the 60s. The only change to the current
forecast was to lower pops for this evening. /27/
Prior discussion below:
Water vapor imagery and RAP H5 analysis indicated relatively
zonal flow across the Southeast, with an upper wave moving across
the ArkLaMiss this afternoon. This is helping to provide lift to
generate showers and a few storms mainly on the northern/eastern
fringes of the CWFA as of this writing. A secondary wave is noted
W of this feature across Nrn TX, and it`s this feature that will
play into the weather for tomorrow/tomorrow night. At the sfc, an
area of low pressure is deepening across NErn OK, with a cold
front sprawled W/SW of this feature across portions of the
Panhandle Regions of TX/OK. Ahead of the front is a dryline, with
dewpoints ahead of this feature teetering in the upper 60s to
lower 70s, and dewpoints in its wake tumbling down into the upper
30 to lower 40s.
Most of the convection currently in the CWFA remains just to the E
and W of I-55 this afternoon, colocated within the Marginal Risk for
svr storms from SPC. While we haven`t gotten any reports of wind
gusts yet from this activity, the better window for this to occur
will be over the next 4-6 hours as the jet gets closer/lift
Aside from the potential for convection through sunrise Friday
morning, an abundance of moisture trapped in the lowest levels of
the atmosphere will set the stage for lingering low clouds and
reduced visibilities overnight. As the threat for thunder wanes
overnight, the associated mixing will decrease, setting the stage
for fog development across much of the CWFA. More
widespread/slightly more dense fog is expected in the Srn zones
where convection hasn`t really overturned the lower/moist levels of
the atmosphere, so expect lower ceilings/more reduced vsbys there
(though this should stay above Dense Fog Criteria attm).
The secondary upper level disturbance currently over TX/OK will move
into the ArkLaMiss Friday into early Saturday, with more showers and
a few storms possible Friday aftn/eve. SPC again has mainly the
Nrn/NWrn areas included in a Marginal Risk for svr storms, mainly
for damaging winds and perhaps some hail.
Saturday overall looks to be a transitional day of sorts across the
area, with the disturbance moving NE and the lower atmosphere finally
drying out a tad compared to days past. PoPs were removed
Saturday night as a result, with the next chance of rain arriving
early next week.
Temperatures during this time will be mild/warm, with daytime
highs in the lower 80s, with morning lows starting out each day in
the lower to middle 60s.
For those who favor the warmer temps, they will stick around
through the weekend and into the beginning of next week thanks to
the upper-level ridge, sfc high and southerly flow in place.
Daytime highs will be in the lower 80s through Tuesday with
overnight lows in the lower 60s through Monday night. This pattern
will keep conditions dry except for an isolated shower brushing
the northern fringe of the forecast area on Monday from an
approaching cold front in the process of stalling out.
The cold front will finally move through the forecast area Tuesday
night into Wednesday. A few showers will start to encroach the
forecast area on Tuesday afternoon, slowly spreading southeast into
Wednesday. Models have come to a better agreement on the timing of
the front, however there is still some timing issues to work out.
Also, there is still a disagreement on the strength of the front.
Regardless, there will be a cool down behind the front! On Wednesday,
look for highs in the upper 60s/lower 70s with overnight lows in
the upper 40s.
00Z TAF discussion:
Southerly flow will bring another round of MVFR/IFR stratus
tonight with perhaps more emphasis on fog in the HGB area where
low level mixing will be slightly less. Expect the stratus to mix
out later Friday morning. A few SHRA/TSRA will be possible,
especially during daytime heating. /EC/
.PRELIMINARY POINT TEMPS/POPS...
Jackson 66 82 64 84 / 12 26 26 17
Meridian 64 81 62 82 / 7 20 23 16
Vicksburg 68 82 64 82 / 15 33 34 17
Hattiesburg 63 82 61 82 / 5 18 18 11
Natchez 68 82 64 82 / 11 26 33 14
Greenville 67 81 64 81 / 19 39 33 16
Greenwood 67 81 64 81 / 22 40 36 24
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1028 PM EDT Thu Nov 2 2017
Issued at 1028 PM EDT THU NOV 2 2017
Upstream we continue to see convection fire up along and near the
cold front. This convection will continue to march eastward
tonight, but not sure that we will have enough instability to keep
it going. However, for now will keep what we have going which
does bring some initial thunder into our western zones by 12Z. The
other issue tonight has been temperatures, as possibly some
downslope flow has eroded clouds. This is allowing the more
shelter valley sites to see 10 degrees or greater splits from the
ridges. Otherwise little changes needed to deal with obs and
UPDATE Issued at 633 PM EDT THU NOV 2 2017
The evening surface analysis shows a cold front still to our NW
and we remain in the return flow side of things this evening.
Despite the return flow, we will see some ridge/valley splits
given some breaks seen in the clouds. Overall the forecast was in
good shape, with only minor changes needed to deal with latest
obs and trends.
.SHORT TERM...(This evening through Friday night)
Issued at 410 PM EDT THU NOV 2 2017
19z sfc analysis shows a well defined area of low pressure moving
through the Southern Plains stretching up into the lower Great
Lakes with a warm front well north of Kentucky. To the east, high
pressure is found along the Eastern Seaboard and these main
features are keeping a steady flow of air from the south at low
levels into eastern Kentucky. As a result, temperatures are
running above normal in the low 70s most places with mid and
upper 50s dewpoints. Winds are generally 5 to 10 mph with gusts to
between 15 and 20 mph from the south to southwest under partly to
mostly cloudy skies.
The models are in good agreement aloft through the short term
portion of the forecast. They all depict nearly zonal flow over
Kentucky at the base of a large and shallow trough. Along the
transition between the trough to the north and higher heights over
the Gulf of Mexico various waves of energy will ripple above the
JKL CWA from later tonight through Saturday morning. An initial
wave impacts the area after midnight with a trailing one passing
Friday night complete with some limited height falls and
divergence aloft. Given the good model agreement at the broad
scale will favor a general blend, though prefer the details from
the higher resolution NAM12 and HRRR - as available.
Sensible weather will feature a quiet evening ahead of an
approaching front. This boundary will keep the winds stirred with
mostly cloudy conditions in place for a mild night. Showers will
push into the area from the northwest for the second half of the
night with a stray thunderstorm possible toward dawn. As the
boundary presses deeper into the area, showers will be a good bet
for eastern Kentucky through the day along with a potential for
thunderstorms over most of the state, as well. Despite the pcpn
and cloud cover, southerly winds along and ahead of the front will
support highs again near 70 degrees. The slow to depart front
will keep the threat of showers and potential thunderstorms going
into Friday night with mild conditions continuing.
Used the CONSShort and ShortBlend as the starting point for all
the short term grids with only minor, point-based, adjustments
made maxes and mins for temps. Did run PoPs higher through the day
Friday than the blend in favor of the NAM12`s depiction with the
better convection moving across quicker and further north.
.LONG TERM...(Saturday through Thursday)
Issued at 315 PM EDT THU NOV 2 2017
The story through the extended will continue to be the
continuation of mild and damp conditions. Saturday will start with
the stalled out front lifting back to the north/northeast as a
warm front with some light precipitation spreading northward with
the front. We may be able to pop a few shallow showers in the
warm sector on Saturday, but confidence is not high with
instability lacking across the area. All in all, rain chances will
show a gradual diminishing trend through Saturday. Eastern
Kentucky will reside solidly in the warm sector on Sunday with
very little if any chance of rain. This will send afternoon highs
well into the 70s, possibly reaching 80 in a few spots.
A strong cold front will then cross the Ohio river valley Sunday
night into Monday with showers and thunderstorms spreading into
Kentucky. Front looks to arrive fairly early on Monday with any
storms likely weakening. Thus, best thunder chances may occur in
the afternoon as the front stalls over the area and we see showers
and storms redevelop. If storms can redevelop, some could become
strong with decent shear in place. However, instability will be in
question with a good deal of cloud cover in place with the front
stalled over the region. The front will remain stalled over the
region into the middle of next week, providing a prolonged period
of wet weather. Given the setup with the front laid out west to
east, some locally heavy rainfall will also be a possibility.
However, models continue to shift around with the evolution the
the first half of next week, so still quite a bit of uncertainty
on how much rain will actually materialize. It does appear, a cool
down will be in store later in the week, as a stronger system
finally pushes the front south and we return to more seasonable
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 737 PM EDT THU NOV 2 2017
We remain under VFR conditions across the region to begin the
period. We are watching a frontal boundary to our northwest that
will slowly push southeast tonight. We could begin to see a few
showers move toward the area toward dawn and better chances
spreading into the region from NW to SE through the day Friday.
This will bring at least MVFR CIGs and VIS at times on Friday, with
a few storms possible mainly in the Lake Cumberland region. The
winds will remain out of the south most of the period before
veering out of the north behind the boundary. This will mainly be
seen late in the period at SYM, but will spread southward beyond
the TAF period.
Area Forecast Discussion
National Weather Service Melbourne FL
955 PM EDT Thu Nov 2 2017
Sprawling high pressure ridge covers the eastern CONUS and western
Atlantic with a broad inverted surface trough axis around 73W. This
will keep synoptic scale NE flow in place overnight, with the local
pressure gradient loose enough to allow winds to back to a northerly
drainage flow overnight.
Skies mostly clear inland with a few clouds along the coast, and
maybe even an isolated brief sprinkle moving onshore the barrier
islands. Inherited forecast is in pretty good shape, about the only
change of note is to add aforementioned low chance for sprinkles
along the coast. Could see some spotty ground fog in a few spots,
but not expected to be of much consequence, expect perhaps in a few
spots NW of I-4.
.AVIATION...VFR. SKC inland and SCT040-050 near the coast with
perhaps an occasional CIG near BKN040.
.MARINE...NE winds around 10KT with seas 2-3FT, building to 3-4FT
well offshore toward sunrise.
.PREV DISCUSSION... /issued 315 PM EDT Thu Nov 2 2017/
...Deteriorating Marine Conditions expected Friday...
Fri...The aforementioned high pressure ridging will continue to get
squeezed and weaken slightly as a cold frontal boundary advances
toward the mid Atlc and Tennessee Valley. N/NNE flow (10-15 mph)
will result as an inverted trough advances toward the eastern
Bahamas. Gradually deepening moisture, weak mid-level trough
northward, and surface heating will combine for a SCHC mention of
light showers KMLB southward to include southeastern Okeechobee
County. Highs generally near 80 degrees to L80s near the coast with
some M80s possible well into the interior.
Weekend...Models indicate little overall change in the pattern with
a high pressure ridge entrenched from the eastern seaboard into the
Gulf of Mexico. An inverted trough is still shown pushing westward
towards Florida while starting to de-amplify Sun. This pattern will
generate a northeast wind flow and slow moistening with precipitable
water reaching to around 1.3 inches on Sun. No changes to PoPs
with a low chance for marine showers along the coast Sat and then
across the area Sun. The air mass will start to feel more humid
with coastal dew points rising into the upper 60s and interior
values to the mid 60s. Max temps will be in the lower 80s, while
some interior sections will reach the mid 80s.
Monday-Thursday...The inverted trough is still forecast to dampen
out early in the period, then a surface high pressure ridge and
mid level ridge will become oriented west-east while the axis
settles into the state. This will diminish onshore flow and shower
chances look too low to mention after Mon. Late in the period the
models suggest a back door front settling down the eastern
seaboard into northern sections, but that looks too sketchy to
include mention of any rain chances. Little change in temperatures
is indicated with lows running at least 5 degrees above normal
and highs about 3-5 degrees warmer than normal.
.AVIATION...Still mainly VFR. SCT-BKN040-060 CIGs will diminish
over the interior this evening. Very ISOLD -SHRA/--SHRA south of
KMCO/KMLB will also come to an end by around sunset. Winds will
become light/variable again this evening/overnight. Guidance
suggests patchy fog along/north of I-4 late overnight/early Fri
morning, but have not bit just yet on adding any tempo groups to
terminal aerodromes here. The HRRR visibility predictor is also not
buying into this at the moment.
Afternoon/Tonight/Fri...Surface high pressure ridging over the
southeast U.S. remains in place thru Fri. An inverted trough axis
will approach the eastern Bahamas by late in the day on Fri.
Enough moisture remains in place for ISOLD-WDLY SCT sprinkles/light
showers again on Fri. Northeast winds may back a bit more tonight
toward the NNE/N and remain generally northerly during the day on
Fri. The pgrad tightens a bit more with winds possibly approaching
15-18 kts over the open Atlc during the day on Fri. Choppy shorter
period seas will result with the increasing northerly winds opposing
the Gulf Stream. Seas generally around 3 ft tonight, but may build
to 4 ft in parts of the Gulf Stream. On Fri, seas will continue
to build to 5 ft over the Gulf Stream and up to 4 ft near shore.
Weekend...A high pressure ridge from the eastern seaboard into the
Gulf of Mexico will provide a northeast wind flow. An inverted
trough over the Atlantic moving westward should maintain a gradient
tight enough to support wind speeds 15 to near 20 knots on Sat.
The trough is forecast to weaken Sun so northeast winds should be
10-15 knots then. Seas look 3-5 feet except up to 6 feet in the
Gulf Stream Sat. Isolated to scattered showers are forecast.
Monday-Tuesday...The inverted trough will gradually wash out and
high pressure will become oriented west-east with the axis across
north Florida Tue. This will generate a weakened northeast to east
wind flow at 5-10 knots with a corresponding drop in seas to 3-4
feet. Only isolated showers are anticipated.
.PRELIMINARY POINT TEMPS/POPS...
DAB 64 80 66 81 / 0 10 10 10
MCO 63 84 66 83 / 0 10 0 10
MLB 66 82 70 82 / 10 20 20 20
VRB 65 81 70 82 / 10 20 20 20
LEE 63 84 65 83 / 0 0 0 10
SFB 63 82 66 83 / 0 10 0 10
ORL 65 83 66 83 / 0 10 0 10
FPR 64 81 70 82 / 10 20 20 20
Area Forecast Discussion
National Weather Service Tulsa OK
756 PM CDT Thu Nov 2 2017
The region lies between 2 different streams of the westerlies
aloft in a highly zonal flow pattern this evening. A fast moving
low amplitude shortwave trough in the northern stream is moving
toward the Great Lakes this evening. Surface high pressure
building over the Midwest in the wake of the system has forced a
shallow wedge of colder air down into NE OK and the Ozarks this
evening. This boundary should continue south with time, eventually
hanging up in the terrain of SE OK and NW AR on Friday.
Radar data has showed scattered shower development across southern
MO this evening, and just recently a shower has popped up in
Carroll county AR. This is occurring in association with the
southward sagging front and its interaction with a moist
southwesterly low level flow. The data indicates that this flow
will gradually weaken and veer with time, suggesting that activity
should wane after midnight. Rain chances should stay east of the
I-49 corridor as well. So far there has been only 1 lightning
strike with the stronger cells in southern MO. There is enough
instability available to justify carrying a slight chance of
thunder in NW AR.
The HRRR is suggesting that stratus will be predominant north of
the boundary, with some fog potential across SE OK and NW AR. Will
monitor trends and add fog if necessary.
.PREV DISCUSSION... /Issued 630 PM CDT Thu Nov 2 2017/
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
IFR/LIFR conditions are expected to engulf area TAF sites late
this evening and into Friday as a slow moving frontal boundary
moves across the region. Conditions may improve into the MVFR
category by the end of the Valid period.
PREV DISCUSSION... /Issued 329 PM CDT Thu Nov 2 2017/
Unseasonably warm conditions this afternoon south of approaching
cold front, resulting in near record high temps in a few
locations. Cold front currently stretches from central Missouri
back into western Oklahoma, and persistent low clouds have kept
temperatures in the lower 50s across much of Kansas this
afternoon. Surface dew points in the 60s have surged north into
the Ozarks this afternoon and as the front encounters this moist
air this evening, isolated to widely scattered convection possible
mainly across northwest AR where boundary will likely hang up due
to the shallow nature of the cold airmass. Coverage and intensity
appears limited as low level flow remains rather weak tonight.
Eventual southward progress of the front will likely be halted by
terrain with a sharp gradient in high temps Friday likely. Also
will see enough upglide north of the front to result in a period
of drizzle along with persistent low clouds across northern
areas, as indicated by forecast soundings of near saturated layer
at lowest levels. Showers and storms possible again Friday near
and east of stalled boundary, but best upper support will be
mainly to our east by that time.
Overall consensus among various guidance is for shallow cold air
to scour out during the day Saturday resulting in warmer temps
over the remainder of the area. However, it should be noted that
the last few runs of the NAM12, which often depicts shallow cold
air better, have been less bullish with this idea which adds some
uncertainty to the high temperature forecast for Saturday across
northeast OK. Have trended high temps down a bit from Tulsa
northwest to account for this, but still far from certain at this
time. By Sunday, all areas back to unseasonably warm weather.
Another shallow front expected to arrive Sunday night into Monday
with unstable but capped airmass south of the front from most of
the day Sunday. Some storm potential may develop near the boundary
by Sunday evening and overnight as the front briefly stalls ahead
of mid level shortwave energy that should arrive mid week. This
will provide the front a stronger push south with increasing rain
chances and temperatures likely dropping back below normal for
Wednesday and Thursday.
.PRELIMINARY POINT TEMPS/POPS...
TUL 52 62 49 78 / 10 10 0 10
FSM 60 79 56 79 / 10 20 10 10
MLC 54 72 54 82 / 10 10 0 10
BVO 49 58 45 74 / 10 10 0 10
FYV 57 71 54 76 / 10 20 10 10
BYV 56 66 55 77 / 20 30 10 10
MKO 55 69 53 79 / 10 10 10 10
MIO 52 63 49 75 / 10 10 10 10
F10 52 67 52 82 / 10 10 0 10
HHW 58 79 57 82 / 10 20 10 10