Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/16/19
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1045 PM EDT Thu Aug 15 2019
.SYNOPSIS...
An upper level disturbance will produce isolated to scattered
showers with isolated thunderstorms tonight. Warm and humid
conditions will be in place tomorrow through the weekend with a
slight to low chance of showers and thunderstorms each day,
especially during the afternoon and early evening hours. Warm, but
potentially unsettled weather will continue into next week as well.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1045 PM EDT...A batch of showers with some embedded
thunderstorms continues to move across central NY into eastern
NY as of 0230 UTC. The activity has been most concentrated over
the Schoharie and western Mohawk Valleys northeast into the
southern Adirondacks, and Lake George Region. The convection has
shown signs of weakening with generally less than 1000 J/kg of
instability per the SPC RAP mesoanalysis. The 0-6 km bulk shear
weakens downstream towards Albany with generally 20-25 kts which
is supported by the 00Z KALY sounding. The latest 3-km HRRR and
NAMnest have the activity rapidly diminishing between 03Z-
06Z/FRI especially north and west of Albany. We increased the
POPs to likely and categorical values in these areas. Some
rainfall rates will generally be in the 0.25-0.50"/hr range with
heavier showers/isolated thunderstorms. We did keep some slight
chance to low chance PoPs in between 06Z-10Z with the boundary
still south of the region, and the tail of the short-wave
trough moving through.
Humidity levels will start to increase, and some patchy fog is
possible due to recent wet soils, and the increasing low-level
moisture. Lows will be in the 60-65F range in the valley areas,
and mid to upper 50s over the elevated terrain.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
The pattern will remain rather similar through the entire short
term period, with our region remaining within the fast west-
southwest flow aloft. Our region will remain on the northern
edge of the strong ridging in place across the central and
eastern CONUS, so several quick moving upper level disturbances
will be passing through the flow from the Great Lakes towards
the Northeast. This will result in a chance for showers and
thunderstorms on both Friday and Saturday, with the highest
coverage generally during the afternoon and evening hours.
With the strong winds aloft, 0-6 km bulk shear will continue to
be 30 to 40 kts each day. However, instability still looks
fairly limited, as rather warm temps aloft will keep instability
to just about 1000 J/kg or less, along with fairly poor mid
level lapse rates. While storms look to be around each day, the
threat for widespread severe weather looks limited. However,
with the warm and humid air mass in place, can`t totally rule
out a rogue gusty pulse storm, as well as the potential for
locally heavy rainfall.
Temps look fairly seasonable, with valley highs in the lower 80s
on Friday and Saturday (70s across the high terrain). Overnight
lows will be in the 60s. Dewpoints will be starting to feel
rather muggy, with values generally in the 60s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Hot and humid conditions look increasingly likely through at least
next Tuesday, as mid/upper level ridging continues to build across
the southeastern U.S. extending northward into the northeast.
Uncertainties remain in timing and southward extent of shortwaves
traversing the Great Lakes and southern Canada through early next
week, which would modulate chances of showers/storms, especially
across the southern Adirondacks and southern VT which will be closer
to any of these passing features.
If these disturbances remain farther north and west, stronger mid
level capping could limit shower/thunderstorm coverage through
Tuesday, especially southeast areas. For now, will indicate isolated
to scattered coverage of mainly afternoon/evening
showers/thunderstorms through Tuesday due to these uncertainties.
Model consensus suggests a stronger shortwave and attendant cold
front may approach/pass through the region sometime later Wednesday
into early Thursday, so will indicate slightly greater coverage of
showers/storms during this period, with decreasing coverage
possible by later Thursday.
High temperatures Sunday through Tuesday should reach the upper 80s
to lower 90s for valley areas, and upper 70s to mid 80s across
higher terrain areas. Dewpoints should remain in the 60s to lower
70s through this period, resulting in maximum heat indices of
between 95-100 for many valley areas. Should confidence increase
that these maximum heat indices will occur, then heat advisories
would be needed. Will address this potential in the HWOALY. With the
potential for more clouds and showers Wednesday, it may be slightly
cooler for highs, mainly in the 80s. By Thursday, highs may cool
into the 70s to lower 80s, or perhaps even cooler depending on the
timing of the next cold front and how far south/east the next
airmass extends.
Overnight lows Sunday-Wednesday mornings mainly in the 60s, although
perhaps only lower 70s within portions of the Hudson River Valley.
Temps should cool into the 50s to lower 60s by Thursday morning.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
An approaching upper level disturbance from the west will
trigger showers and isolated thunderstorms this evening for
KGFL, KALB, and KPSF. Another upper level disturbance could
bring isolated to scattered showers and thunderstorms for Friday
afternoon.
Showers continue expanding east/northeast and will continue to
affect KGFL, KALB and KPSF through 04Z/Fri. There could be an
embedded thunderstorm, but coverage of thunderstorms should
remain limited and therefore will keep out mention in current
TAFs. Locally heavy rainfall could occur, especially at KGFL.
After 04Z/Fri, showers should taper off. Low clouds/fog may then
form, especially at KPOU and KGFL, where IFR/LIFR conditions are
possible. Elsewhere, mainly MVFR to IFR conditions are expected,
especially for Cigs.
On Friday, MVFR/IFR stratus may persist until late morning,
especially at KPOU. Expect mainly VFR conditions for the
afternoon. However, isolated to scattered showers and a few
thunderstorms will be possible in the afternoon, especially for
KGFL and KALB.
Light/variable winds overnight will trend into the southeast to
south at 5-10 KT Friday.
Winds will be stronger, and variable in direction in and near
any thunderstorms.
Outlook...
Friday Night through Tuesday: Moderate Operational Impact.
Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
Thanks to a couple of passing upper level disturbances, there
will be a threat for scattered showers and thunderstorms over
the next few days, especially during the afternoon and evening
hours. RH values only look to lower to 50 to 60 percent each day
during the afternoon and winds will be fairly light. During the
overnight hours, RH values will recover close to 100 percent,
and some dew and fog formation will be possible as well.
&&
.HYDROLOGY...
Widespread hydrological issues on the main stem rivers are not
expected the next several days.
Through the weekend and into early next week, there will be a
isolated to scattered threat for showers and thunderstorms each
day, mainly during the afternoon and evening hours. There will
be a threat for locally heavy downpours, especially by the
weekend, as humidity levels and dewpoints will be increasing.
Any thunderstorm will be capable of producing flooding of urban,
low lying or poor drainage areas.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis/Wasula
NEAR TERM...Wasula
SHORT TERM...Frugis/Wasula
LONG TERM...KL
AVIATION...KL/NAS
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service Denver/Boulder CO
854 PM MDT Thu Aug 15 2019
.UPDATE...
Issued at 854 PM MDT Thu Aug 15 2019
Weak shower activity continues moving over northeast Colorado with
mostly virga and gusty winds. Brisk outflow from thunderstorms
over the northeast corner of the stateis bringing wind gusts into
the 20s into the Denver area along with dew points climbing into
the lower 50s. Temperatures have cooled into the lower and mid
70s, so the airmass should remain too stable for any additional
showers to develop as the outflow runs up against the foothills.
Had updated the forecast to include isolated shower activity over
parts of the northeast through about midnight, so no other updates
are necessary. The latest HRRR doesn`t show any significant shower
activity or any fog developing overnight. Just diminishing winds
after the outflow boundaries run their course.
&&
.SHORT TERM...(This evening through Friday)
Issued at 236 PM MDT Thu Aug 15 2019
Hot dry air has pushed back into the I-25 corridor as expected. On
the eastern part of the plains temperatures are cooler and the
airmass will likely remained capped, with a slight chance of
storms over the northern border and maybe the west part of the
Palmer Divide early this evening. There is still a slight chance
of tonight`s Nebraska MCS clipping the northeast corner of the
state as well, though it will probably be further east.
We still prefer an intermediate solution for the amount of cooling
and moisture that comes in Friday morning. With less convection
today, and those storms probably east of our area, the threat of
fog making it all the way in to Denver looks less than it did
before. The cooler temperatures will mean the we will likely be
capped most of the day tomorrow, but there will probably be enough
moisture for some storms late in the day and a better chance in
the evening. With better moisture, when we do get storms there
would be a threat of severe storms with CAPEs ranging from 1500 to
3000 J/kg. The highest CAPEs may actually be closer to the
mountains in the late afternoon/early evening if it gets warm
enough, which is still uncertain.
.LONG TERM...(Friday night through Thursday)
Issued at 236 PM MDT Thu Aug 15 2019
Models have zonal flow aloft for the CWA Friday night and
Saturday. Saturday night through Sunday night, the upper ridge
builds back into Colorado. There is a bit of weak upward synoptic
scale energy for the CWA Friday night. There is downward energy in
place Saturday night and Sunday. The low level winds are pretty
weak through the period and generally adhere to normal diurnal
trends with some downsloping mixed in. Moisture-wise, there is
some around Friday evening, then it gets pretty sparse through
Sunday night into the extended period. There is pretty decent CAPE
in place over the plains Friday evening. There is way less for
late day Saturday, the highest values over the southern CWA. For
late day Sunday, there may be some CAPE over the far eastern
border. For pops, will go with "scattered"s over the plains Friday
evening, then 10-20%s over the western half of the CWA for late
day Saturday. No pops for Sunday. For temperatures, Saturday`s
highs are 1-2 C warmer than Friday`s. Sunday`s highs are 2-3 C
warmer than Saturday`s. For the later days, Monday through
Thursday, the upper ridge is centered right over Colorado all four
days with pretty weak flow aloft. Monday is pretty dry but there
is some increase Tuesday through Thursday. Temperatures look to
remain a bit above seasonal normals.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 854 PM MDT Thu Aug 15 2019
Winds have shifted to the east and northeast with the arrival of
outflow boundaries from northeast Colorado showers earlier this
evening. Winds should remain out of the east for a few more hours
and then become more southerly after midnight. No other aviation
impacts are expected. However, with dew points now in the lower to
mid 50s, if winds remain out of the east and skies clear out, then
some radiation fog may develop. When winds transition to drainage
southerlies, there should be enough drying to keep fog from
forming.
&&
.FIRE WEATHER...
Issued at 236 PM MDT Thu Aug 15 2019
The mountains will be dry again on Friday with a bit stronger
winds than today. Gusts of 30 mph should be common in the
afternoon, and minimum humidities will be around 15 percent. This
will create marginal Red Flag conditions for much of the afternoon
in the mountain valleys. Fuel conditions likely vary depending on
recent rainfall, but in general they are getting to the point
where rapid fire spread is possible with very high fire danger
indices.
Above normal temperatures and a drying airmass will create
elevated fire weather weather conditions both Saturday and Sunday
afternoons and early evenings.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 8 PM MDT Friday for COZ211-213-214.
&&
$$
UPDATE...Dankers
SHORT TERM.....Gimmestad
LONG TERM......RJK
AVIATION...Dankers
FIRE WEATHER...Gimmestad/RJK
Area Forecast Discussion
National Weather Service Caribou ME
1114 PM EDT Thu Aug 15 2019
.SYNOPSIS...
High pressure will move eastward into Canadian Maritimes
overnight. Numerous upper level disturbances will move across
the state Friday through Sunday. A cold front will cross the
state later Monday.
&&
.NEAR TERM /THROUGH FRIDAY/...
1115 PM Update...
Temps were adjusted to fit the latest obs and conditions. The
satl showed high clouds pushing ne. The latest sky forecast was
matching up w/this situation quite nicely. Decided to push the
precip chances back by at least 6 hrs as the latest RAP was
matching up w/the regional radar showing rain well back across
NYS. RAP showed rain moving into western areas by mid morning.
Previous Discussion...
The high pressure system will provide one more cool night
before moving eastward into the Canadian Maritimes on Friday.
Under a shallow inversion, lows will be in the low to mid 50s,
but upper 40s are possible in cooler spots of Aroostook County.
Some mid and high level clouds will arrive in northern zones
just before sunrise and keep temps from dropping any lower.
These clouds will be in association with an H700 trof
propagating northeastward from Vermont. This mid level trof will
be the main feature for Friday, bringing clouds and some shower
activity with a weak baroclinic zone. The showers will be
enhanced by the entrance region to a weak upper jet too.
Nonetheless, both the upper level and surface trofs will rapidly
decay as they move into the powerful high anchored in Maritime
Canada. Most of the area will measure less than a tenth of inch
of precip in the morning...if anything... except perhaps the
Moosehead Lake region. No instability is expected and thunder
remains out of the forecast. In spite of warm advection, the
clouds and onshore flow will produce highs that are about the
same or slightly lower than today`s readings. The other item of
interest with the developing onshore flow will be the arrival of
fog and stratus along the coast. For late tonight, it may reach
the outer islands of Hancock County before retreating Friday
morning. It will return Friday evening along the entire coast.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Upper level westerly flow will be over the area Friday night
through Sunday with several upper level shortwaves, while at low
levels we will be under onshore southerly flow.
Friday night...Marine layer setting up Downeast then moving
inland. Widespread low clouds with some fog. Only a chance of
light showers.
Saturday and Saturday night...Weak upper level shortwave trough
moves through Saturday afternoon and evening. This will bring
an increasing shower chance. Went with likely PoPs in far
North/Northwest Maine (best upper level dynamics), with chance
PoPs elsewhere. Marine layer firmly entrenched thus only a small
chance of thunder mainly extreme NW. Fairly muggy, but marine
layer will keep temperatures down Saturday with highs around 70.
Marine layer persists into Saturday night with areas of fog.
Shower chances decreasing (but not totally going away) through
the night as upper level shortwave exits.
Sunday...Sunday`s a bit tougher day to pin down. Area seems to
be in between upper level shortwave troughs in zonal flow.
Airmass will be quite muggy, while marine layer seems to weaken
a bit. If clouds can break some, could get storms, but if clouds
persist, may just be a few showers and that`s it. Zonal flow in
between shortwave troughs doesn`t really help convection. For
now went with partly to mostly cloudy skies and a chance of
showers with a slight chance of storms. A bit warmer with highs
in the mid to upper 70s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Monday appears to be the most active day with a cold front
moving through around late Monday. Doesn`t look like a strong
system, but enough that put chance to likely PoPs in the
forecast with a chance of storms as well.
A bit less muggy on behind the cold front Tuesday with just a
slight chance of showers, though can`t rule out cold front
stalling out Downeast which would keep higher precip chances
there if that were to happen.
Model agreement goes down Wednesday through Friday. There is a
recent model trend toward a decent upper level low diving
southeast out of Quebec and toward our area, which would lead to
increased precipitation chances especially Wednesday and perhaps
into Thursday. However, as mentioned, still plenty of model
disagreement and only trended forecast some toward this
solution.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR conditions are expected. There is a chance of
shallow fog near sunrise at HUL, BGR and BHB. The fog won`t last
long. IFR cigs are possible at BHB by Friday evening.
SHORT TERM:
Friday Night... IFR ceilings likely Downeast with MVFR
developing Northern Maine later in the night.
Saturday...Likely remaining MVFR through the day Downeast and
perhaps improving to VFR in the afternoon in the north.
Saturday night...Widespread IFR ceilings, especially later in
the night.
Sunday...Improving to VFR most areas in the afternoon.
Sunday night and Monday...Mostly MVFR with some IFR especially
near the coast. Chance of storms.
Monday Night and Tuesday...Improving to VFR most areas.
Winds...Mainly light, except a bit breezy Monday afternoon with
a cold front.
&&
.MARINE...
NEAR TERM: Winds will remain light and seas will continue to run
around 2 feet or less. Fog will become a concern later
tonight...mostly towards coastal Hancock County. Any fog will
dissolve in the morning, but will reform along the coast in the
evening.
SHORT TERM: Remaining below small craft. Fog will be an issue
through Sunday, then gradual improvement Monday and Monday
night.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service State College PA
337 PM EDT Thu Aug 15 2019
.SYNOPSIS...
A trough of low pressure will keep the weather unsettled
for the next several days. Temperatures will remain near normal
and it will be rather humid. By late in the weekend into early
next week look for hot and humid conditions, especially across
the southeast portions of the area.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Radar shows numerous showers and thunderstorms breaking out
under the strong August sun. The near term CAMs continue to
advertise a noisy afternoon. RAP shows ML CAPE between
1500-2000J with moderate shear. SPC has issued a SWOMCD with a
40% of a watch. Isolated rotating storms will be possible as we
progress into the afternoon.
The highest threat will be for some gusty winds with the
strongest storms along with brief heavy downpours.
Convection will continue into the evening hours before
decreasing in coverage and intensity later. It will be a muggy
night with patchy fog if skies manage to clear at all. Lows will
be in the 60s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Weak upper troughing will once again tend to lead to mainly
diurnal showers and thunderstorms Friday. Models develop
moderate instability and shear so we could be looking at a
virtual repeat of today.
Highs will range from the upper 70s to mid 80s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Prevalent zonal west-southwest flow aloft will persist from
this weekend through the early part of next week before
significant pattern amplification unfolds over the CONUS. A
strong upper builds builds from the Four Corners region to the
south central Plains by mid week. Downstream upper troffing will
be prevalent over much of the GLAKS and eastern seaboard, with
perhaps a trend towards slightly less heat and humidity late
next week. It still looks quite warm however.
Initially, a very warm air mass should build north and east
into PA this weekend with heat indices by Sunday likely topping
90F over much of the southeast. Mainly diurnal convection
chances persist each day, although in this pattern most areas
will remain dry at any given time, and scattered
afternoon/evening variety is favored.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Most of the area as improved to VFR, and any impacts going into
the evening will be confined to those terminals that experience
a hit from the scattered thunderstorms that are breaking out.
Low clouds and fog are expected to bring more widespread
restrictions again tonight into early Friday morning, with
Friday afternoon seeing scattered showers and thunderstorms
developing once again.
.Outlook...
Sat-Tue...VFR. Isolated-scattered showers/thunderstorms
possible, mainly in the afternoon/early evening hours. Late
night and early morning fog/low clouds.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...La Corte
LONG TERM...Ross
AVIATION...DeVoir
Area Forecast Discussion
National Weather Service Cheyenne WY
233 PM MDT Thu Aug 15 2019
.SHORT TERM...(This evening through Saturday)
Issued at 233 PM MDT Thu Aug 15 2019
A couple strong to severe storms moving across northern Goshen
county presently. These likely set off by the southern fringe of a
shortwave moving across South Dakota as well as a diffuse outflow
boundary. Some question as to how far they will progress into the
Panhandle the rest of the afternoon. Of more concern is the
likelihood for another round of strong convection later this
evening/tonight up north as another shortwave passes by, a
similar setup to last night. Activity should move out of the CWA
very late tonight or early Friday morning.
Friday and Saturday will continue to have a chance for convection
mainly east of the mtns but should be isolated. Sufficient shear
and instability for a few strong to severe storms but forcing
remaining rather low.
.LONG TERM...(Saturday night through Thursday)
Issued at 233 PM MDT Thu Aug 15 2019
A warmer and mainly dry weather regime should build into the area
Sunday into early next as the upper high builds over the region
and the stronger westerlies lift well north of the area. Chances
for isolated mainly late day showers and storms should return by
midweek as a bit of moisture lifts northward into the region.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1055 AM MDT Thu Aug 15 2019
Nocturnal thunderstorms and low flight categories look to return
to the Nebraska Panhandle and KCYS tonight...similar to what we
had this morning. HRRR guidance showing this as well as LAMP MOS
guidance. Generally followed both of these forecast tools for the
18Z TAFs today. Looks like KAIA could get hit pretty good this
evening as HRRR simulated radar shows a severe storm moving
through KAIA around 08Z. Still too early to put that in the KAIA
TAF...but later shifts may need to add.
&&
.FIRE WEATHER...
Issued at 233 PM MDT Thu Aug 15 2019
Little change is seen in the weather conditions through the
weekend with critical to near critical conditions looking to
remain confined to southwestern Carbon county. Another round of
showers and storms is expected mainly over east central Wyoming
across the northern Nebraska panhandle tonight with more isolated
activity east of the mountains Friday and Saturday. Mainly dry
and warmer conditions will move in Sunday and continue into early
next week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ304.
Fire Weather Watch from Friday afternoon through Friday evening
for WYZ304.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...RE
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
628 PM CDT Thu Aug 15 2019
.SYNOPSIS...
Issued at 330 PM CDT Thu Aug 15 2019
H5 analysis this morning had High pressure anchored
along the AZ/NM border. North of this feature, broad westerly flow
extended from the Pacific NW, east southeast into the Ohio Valley.
Within this flow, three distinct shortwaves were noted this morning.
The first was over Nebraska, a second over eastern Montana, and a
third over Washington state. As of midday, WV imagery had the
Nebraska shortwave over SE Nebraska. The Montana wave was just about
to enter western North Dakota and the Washington state wave, was
crossing the Idaho panhandle. Strong subsidence was noted in the
wake of the Nebraska shortwave today, and has led to clear skies
across western and north central Nebraska. Temperatures as of 2 PM
CDT ranged from 75 at North Platte to 83 degrees at Valentine.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 330 PM CDT Thu Aug 15 2019
An active pattern will
continue over the next 24 to 36 hours across the high plains.
Convective cloudiness in association with the Dakota shortwave
continues to develop currently over eastern portions of Wyoming.
This activity will approach western portions of the forecast area
around 4-6 PM CT this evening per the latest HRRR and NAMNEST solns.
As this activity works east into west central and central Nebraska
mid evening, mid and upper level dynamics weaken quite a bit where
widespread thunderstorms were earlier today. More widespread
thunderstorm chances will arrive during the overnight hours. A
strong shortwave, currently crossing the Idaho panhandle, will dive
to the southeast into Wyoming this evening. Strong mid level warm
air advection in advance of this feature, will overspread eastern
Wyoming and the Panhandle during the mid to late evening hours.
Favorable lift will transition to the east southeast overnight
across the forecast area with precipitation chances continuing into
the overnight. As for the severe threat: Steep mid level lapse rates
and decent elevated CAPE is noted in the panhandle and eastern
Wyoming this evening, which would be very favorable for large hail.
However, once you travel east of the panhandle, mid level lapse
rates and CAPE values drop rapidly. This would limit the hail threat
across western and north central Nebraska tonight. The threat for
strong thunderstorm winds appears limited as well as the best D CAPE
is confined over far swrn Nebraska this evening. Thunderstorms are
expected to exit the forecast area Friday morning with a brief lull
in storms for most of Friday afternoon. By late afternoon,
thunderstorms will begin to develop across nern Colorado INVOF of a
surface boundary and thetae ridge. This activity will ride east into
the evening hours with the best chances for precipitation being
across southwestern portions of the forecast area. As activity
transitions east across the forecast area, it will encounter limited
CAPE and weaker lapse rates, which should limit the severe threat.
.LONG TERM...(Saturday through Thursday)
Issued at 330 PM CDT Thu Aug 15 2019
A northern stream low and trough of low pressure aloft will
approach and track through the forecast area Saturday into
Saturday night with another chance for showers and thunderstorms.
Starting Sunday, high pressure aloft will build into the southern
Rockies and southern Plains. H5 Hts will rise 80 to 100 meters
from Sunday into Monday. This will lead to drier and warmer
conditions across the forecast area through Tuesday. Ridging in
the central CONUS will begin to break down midweek next week as a
trough of low pressure deepens across the PAC NW. As lead
shortwaves lift across the intermountain west, the high will
retreat south. This will result in cooler temps and an increased
threat for precipitation.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 628 PM CDT Thu Aug 15 2019
Isolated thunderstorm activity this evening becomes scattered
after midnight and lasts through noon Friday. This thunderstorm
activity is associated with an upper level disturbance, currently
operating across nwrn WY/swrn MT, which will move through wrn and
ncntl Nebraska later tonight. An area of IFR/local LIFR in fog
may form south of Interstate 80, 09z-15z Friday morning.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1016 PM EDT Thu Aug 15 2019
.SYNOPSIS...
A cold front will remain stalled to the west through Friday
then dissipate over the region this weekend. High pressure
offshore will dominate early next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1010 PM Thursday...Scattered thunderstorms still confined
to the northern tier of the CWA from Martin County east along
the Albemarle Sound, and over the central Outer Banks. High-
resolution models continue to struggle with placement and extent
of convection and will use a combination persistence/consensus
approach for the near term forecast. Think the current
convection over the northern tier will wane in the next hour or
two with a lull in convection overnight, except for perhaps a
few light showers. HRRR and 3km NAM show convection refiring
near the coast toward morning (09z and later) before working its
way inland later tomorrow morning. PoPs have been adjusted to
reflect this trend, although confidence is still fairly low.
Heavy downpours will be possible in any of the stronger storms
as precipitable water values remain well over 2 inches. Lows
continue above climo, in the mid/upr 70s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
As of 230 PM Thu...The front will remain stalled just to the
west Friday, as shortwave energy continues to rotate through the
upper flow. Deeper moisture will shift toward the coast as low
level southerly flow continues. Scattered showers expected, with
best chances in the morning along the coast. Heavy rain possible
along the coast early. Low level thickness values, cloudy
skies, and southerly flow support highs in the mid to upper 80s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
As of 230 AM Thu...A cold front will dissipate N of the region
thru weekend with sct shra and tsra from time to time espcly
cst. Ridging over the Atlantic will extend over the area early
to mid next week with wdly sct to sct convection and typical
summertime heat and humidity.
Fri night through Sun...Better moisture begins to shift to cst
late in week into the weekend as front dissipates N of area.
Will keep chc pops mainly for the cst this weekend with slight
chc inland. No signif airmass change with highs upr 80s/lower
90s and lows in the 70s.
Mon thru Wed...Ridging over the Atlantic will dominate this
period. Mdls do show weakness aloft to the W and this may at
times lead to some increased chc of convection but overall looks
like typical summertime pattern of wdly sct to sct convection
with better chcs inland in aftn and evening. Temps will cont
near to slightly above normal with upr 80s and lower 90s for
highs and muggy 70s for lows.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Short Term /through 00z Saturday/...
As of 625 PM Thursday...Very low confidence TAF this cycle with
many different solutions with regards to coverage and extent of
convection during the next 24 hours and its impact on flight
operations. Using a consensus of the HRRR and NAM 3km shows the
current scattered convection waning a bit overnight before
redeveloping near the coast early Friday morning, then
translating inland during the afternoon. Deep low-level moisture
and a wet ground from early convection will lead to patchy
IFR at KPGV, KISO and KOAJ and MVFR fog at KEWN for the 09z-12z
period in the morning. Will include VCTS in all TAFs starting
around midday on Friday.
Long Term /Fri night through Tuesday/...
As of 230 AM Thu...Deeper moisture begins to shift mainly E of
taf sites Fri into early next week with less shra/tsra coverage
and mainly VFR. As usual some patchy fog/st poss late
night/early morn with high dewpts and rather light winds.
&&
.MARINE...
Short Term /through Friday/...
As of 1015 PM Thursday...Wind directions a bit confused at late
evening due to convection, but generally are SE over the
northern zones and SW over southern marine areas. Seas continue
at 2-3 feet. Wind speeds are mostly 5-15 knots. Front will
remain to the west through Friday and SW 10-15 kt will continue
across the waters. Seas will remain 2-4 ft overnight and
continue into Fri.
Long Term /Fri night through Tuesday/...
As of 230 PM Thu...Models are trending a bit stronger with the
SW winds Friday night into the first part of Sat. The GFS and
NAM are quite a bit stronger than other guidance, developing SCA
conditions, winds 20-25 kt and seas building to 4-7 ft.
Increased winds from previous forecast, still some uncertainty
but a period of SCA could develop. Front will dissipate to the N
with offshore high pres cont to dominate. This will lead to
mainly S to SW winds 8 to 15 kts thru pd with 2 to 4 foot seas.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...RF
AVIATION...CTC/CQD
MARINE...CTC/CQD
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
604 PM CDT Thu Aug 15 2019
.UPDATE...For 00Z Aviation discussion below
&&
.SHORT TERM...(This evening through Friday night)
Issued at 303 PM CDT Thu Aug 15 2019
Short term concerns remain severe convective potential into this
evening.
Latest short range HIRES models showing potential for bowing
complex moving into southwest MN early this evening. Have trended
PoPs this way at the moment. MLCAPE to 2000 J/kg ahead of the
front over eastern South Dakota along with forecast shear to 35
kts or so into southwest MN would favor some sort of severe
potential. If a cold pool develops along the convective line, a
bowing structure would be likely per HRRR trends. Heavier cumulus
over eastern MN may yet yield an isolated shower/thunder late
this afternoon/evening. SPC SWOMCD earlier indicated possible WW
into SW MN for the evening. Will continue to monitor overall
trends.
The upper trough moves east into western WI by Friday morning.
The convective potential should gradually wane through 06z Fri as
the system moves east. CLouds and some fog is possible as the
system exits to the east late. Bufkit profiles suggest lower
humidity to remain much of Friday morning before lifting,
especially to the east. The front exits over Wisconsin by Friday
afternoon and should take most of the convective threat with it.
Various HIRES models along with the deterministic models develop
some convective potential into eastern MN again later Friday
afternoon. Instability increases and we may see a weak convergence
trough develop over eastern MN late afternoon which could trigger
at least some isolated thunder. Will include a low end PoP for
this possibility.
.LONG TERM...(Saturday through Thursday)
Issued at 303 PM CDT Thu Aug 15 2019
Showers and thunderstorms continue to look possible this weekend,
as an upper-level low over northern Alberta/manitoba drags a cold
front across the region. Models have come into better agreement
with the timing of the front, with the best chance for
precipitation now looking like Saturday evening into Sunday
morning. Some uncertainty still exists on how widespread showers
and thunderstorms will be along the front, as central/southern
Minnesota and western Wisconsin will be split between areas of
better forcing with the upper level low to our north and a
shortwave tracking to our south. Moisture return into the Upper
Midwest looks to be rather paltry as well as a stationary front
across Iowa/Illinois will block the flow of Gulf moisture into the
region. Will continue to keep PoPs in the chance range saturday
evening to Sunday morning, with further refinement expected as we
are able to add higher resolution CAMs into the forecast. Not
expecting any heavy rain or severe weather concerns with the lack
of deep Gulf moisture over the region, although will have to watch
the shortwave to our south and potential for stronger storms
across southern Minnesota if guidance shifts its track farther
north.
Beyond Sunday, the forecast looks drier as zonal aloft
transitions to drier northwest flow thanks to ridging building
into the central US. Guidance has shown some consistency with
developing a convective complex Monday night into Tuesday as a
shortwave rounds the periphery of the ridge to our southwest. Will
keep PoPs low as there is little confidence in resolving the
details with mesoscale features at this range. Temperatures will
generally be warmer next week as heights rise and southerly flow
develops over the region, but we may see a brief cool-down midweek
as troughing develops over eastern Canada and its influences
extend into the western Great Lakes.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 604 PM CDT Thu Aug 15 2019
Showers and thunderstorms look to spread east across the area
tonight. Strong winds appear possible at western sites (KRWF and
KAXN) as the line of storms moves through, but should see
decreasing intensity with eastward progression. Attendant MVFR
conditions are expected with the precipitation, with MVFR/IFR
ceilings persisting overnight in the wake of the precipitation.
May see areas of fog with MVFR visibilities as well. Improvement
to VFR will occur late Friday morning and afternoon.
South/southwest winds shift to west/northwest for Friday.
KMSP...
Expect showers and isolated thunderstorms between 05Z and 09Z,
with MVFR ceilings in the wake of the precipitation. Expect
ceiling to improve to VFR around 17Z Friday.
/OUTLOOK FOR KMSP/
Sat...VFR with MVFR/TSRA possible. Wind SW 10 kts.
Sun...VFR. Wind SW 10 kts.
Mon...VFR. Wind S 5 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...DWE
LONG TERM...ETA
AVIATION...LS
Area Forecast Discussion
National Weather Service Marquette MI
747 PM EDT Thu Aug 15 2019
.SHORT TERM...(This evening through Friday)
Issued at 418 PM EDT THU AUG 15 2019
WV imagery and RAP analysis indicated a broad trough through the
northern CONUS. A weak shortwave trough was moving east of Upper
Michigan while the next significant shrtwv was located over the
central Dakotas. Although low level moisture was limited, SBCAPE
values in the 250-500 J/Kg range with daytime heating was enough to
support some sct/isold -shra over the west half of Upper Michigan.
Tonight, expect any lingering -shra over central Upper Michigan to
dissipate this evening with the loss of dayimte heating. After a
period of favorable radiational cooling allows temps to drop into
the lower 50s inland, increasing clouds late over the west half will
keep readings from falling further. Some shra and possibly and isold
tsra may move into the far west late.
Friday into Friday night, sct/nmrs shra will spread through the area
supported by moderate 700-300 qvector conv ahead of the shrtwv.
Although cloud cover will limit surface heating, there may be enough
elevated instability for a few tsra, similar to what was observed
over North Dakota. Shra and a few tsra over the east should move
east of the area by late evening with clearing moving into the west.
.LONG TERM...(Saturday through Thursday)
Issued at 347 PM EDT THU AUG 15 2019
The large-scale long-term pattern initially looks to be a
continuation of what we`ve seen the past several days: broad ridging
stretching across most of the central and southern U.S., and an
active northern stream across southern Canada with occasional dips
in the jet that reach as far south as the Northern Plains and Great
Lakes. That ridging builds all the way northward to near the
Canadian border early next week before the pattern amplifies and the
next system drops down across the Great Lakes towards the middle of
next week.
Yesterday`s battle between the EC and the rest of the guidance re:
FROPA timing this weekend seems to be settled...in the EC`s favor.
There will be a subtle mid-level short wave lifting northeastward
into Wisconsin by Saturday afternoon, but with heights rising out
ahead of it, plenty of dry air aloft, and all of the models dry
through the day Saturday, have cleared out POPs - except for some
chance POPs creeping in over far western Lake Superior in the
afternoon. Therefore Saturday actually looks like quite a nice day
now, with just a few clouds around and highs right around 80 for
most.
But ultimately that cold front and its associated shower/storm
chances are delayed - not denied. The front should come through
Sunday from west to east across Upper Michigan. And whereas
yesterday I said the timing did not support organized or widespread
thunderstorms, today I may have to eat my words. The slowing trend
in the models allows much if not all of the region to destabilize up
to 2000 J/kg MUCAPE in the NAM, GFS, CMC, and EC. With 40-45 knots
of 500 mb flow, 0-6 km bulk shear vectors in the above models all
range from 35 to as high as 50 knots in the warm sector, suggesting
strong to severe storm organization might be possible. PWATs rising
above 1.5" also introduces a slight flash flood risk, but given the
seasonably fast mid-level flow mentioned above, this risk would
probably only materialize in an isolated instance or two of training
storms. All that said, we`re still 3 days out and I suspect the
FROPA timing might not be settled just yet either, so stay tuned.
With high pressure behind this wave, have kept Monday dry and warm,
but it`s a short-lived reprieve. The next short wave approaches
Tuesday, but the model blend seems to bring PoPs in a bit early/too
northerly Monday night, so have trimmed that back. Still think there
will be at least a slight chance of showers and storms by Tuesday
afternoon, though. Strong high pressure by August standards settles
in Wednesday through the remainder of period. With 850 mb temps
dropping to around 5 C behind this wave/cold front, the end of the
week next week looks like some comfortable days and perhaps a few
chilly nights, but given how far out this is, have not strayed far
from the model blend for temps at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 747 PM EDT THU AUG 15 2019
A few showers continue over western Upper Michigan this evening but
will die off with the loss of daytime heating. Skies will stay VFR
overnight, with the potential for MVFR ceilings with the next round
of precipitation approach of the convective activity currently over
the northern plains during the day. At KIWD, have included mention
of BCFG for tonight as winds to be light and skies will clear for a
period this evening.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 418 PM EDT THU AUG 15 2019
Winds over the lake are expected to stay at or below 20 knots for
the majority of this period. Models continue to show the chance at
an active period of weather this weekend. Expect chances of showers
and thunderstorms through the weekend. Latest model runs have backed
off on the gusts for Sunday slightly but there still remains a fair
chance at gusts up to 25 knots on Sunday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...lg/RJC
AVIATION...RJT
MARINE...JLB
Area Forecast Discussion
National Weather Service Pueblo CO
259 PM MDT Thu Aug 15 2019
.SHORT TERM...(This evening through Friday)
Issued at 257 PM MDT Thu Aug 15 2019
Isolated and weak convection developing across the San Juans at
mid-afternoon, with a couple cells farther east on the plains in Las
Animas County as well. Expect isolated activity to continue until
sunset, with HRRR suggesting perhaps a stronger cell or two
lingering toward midnight in Kiowa/Prowers counties where low level
moisture/instability is greatest. Weak surface boundary then backs
westward toward I-25 overnight, though lack of much in the way of
organized convective outflow suggests any lower clouds and deeper
moisture should stay farther east toward the KS border. On Fri,
slightly stronger upper wave crosses the area, which should increase
thunderstorm chances over most of the higher terrain in the
afternoon. Rather meager low level moisture will still be the
limiting factor for storms, with most activity fairly high based and
weak. On the plains, deeper low level moisture and instability north
of the Arkansas River and near the Kansas border may aide in the
development of a few strong/severe storms late in the afternoon,
especially Kiowa County which is clipped by the SPC SWODY2 slight
risk for tomorrow. Max temps may drift down a degf or two at many
locations Fri, as minor height falls push into the region.
.LONG TERM...(Friday night through Thursday)
Issued at 257 PM MDT Thu Aug 15 2019
An upper disturbance will be exiting CO to the east late Fri evening
with shower/tstms over the far southeast CO plains ending before
12Z Sat. Limited moisture over the area on Sat should lead to only
some isolated chances for precip, mostly over the mtns, high
valleys, and Palmer DVD. High temps on Sat will be in the 90s
across the southeast plains, and in the lower to mid 80s in the
San Luis and Upper Arkansas River Valleys.
Sun and Mon the upper ridge builds back over CO, and there will be
little moisture over the area. Dry weather is expected both days,
along with above average temps. Highs across southeast CO will be
in the 90s, with lower 100s expected along the Arkansas River Valley
from the Pueblo area to the KS border. The San Luis Valley and the
Upper Arkansas River Valley should see highs in the mid to upper 80s.
Moisture is expected to move back into the area for Tue and Wed, and
a weather disturbance is expected to move across the state on Wed.
Chances for showers and thunderstorms will return to most of the
area these day, but especially over the mtns. Thu precip should
mostly be confined to the mtns and adjacent lower elevations.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 257 PM MDT Thu Aug 15 2019
VFR at all taf sites the next 24 hrs. Very low risk of a tsra
late this afternoon into early this evening at KALS, while drier
air limits tsra chances at KPUB and KCOS. On Thu, deeper moisture
remains just e-ne of the area, with only isolated afternoon
convection expected over mainly the ern mts and plains. Again,
chances for tsra look too low to mention in the taf.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...28
AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Tulsa OK
951 PM CDT Thu Aug 15 2019
.DISCUSSION...
Strong to severe storms across northeast Kansas are dropping south
southeast and will at least pose some threat to parts of
northeast Oklahoma and northwest Arkansas late tonight into Friday
morning. Most of the latest data keeps the activity to our north
and east, but the latest HRRR does show some development to the
west across northeast Oklahoma Friday morning. Given current radar
trends, feel some mention of showers and storms remains warranted,
but did remove pops prior to 06Z, and lower them slightly between
06-12Z. The rest of the forecast looks good at this time.
Update on the way.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...20
LONG TERM....05
PLATE