Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/12/20
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
403 PM AKDT Thu Jun 11 2020
.SYNOPSIS...
Isolated to scattered afternoon and evening showers and
thunderstorm are expected across the Interior this evening as well
as for the next several days. The best chances for storms today
and Friday will be in areas east of Fairbanks. The northwest
Arctic will see showers tonight thanks to an upper level low that
is currently in place over Kotzebue Sound. This low and the
associated showers will move north tonight and Friday. A warming
trend in temperatures is expected for the Interior and the west
coast over the next few days as a ridge builds over the area.
&&
.DISCUSSION...
The 12 UTC model suite generally initialized well when compared
to the obs. The models all have the same general idea with the
synoptic scale pattern out through early Saturday; however, by
Saturday evening the models start to diverge. The GFS is much
more aggressive than the NAM or with its handling of an easterly
wave that will push across the Interior late Saturday into Sunday.
For the afternoon forecast package, we will lean more on the NAM.
Aloft, at 500 mb, a 543 dam low is currently in place over
Kotzebue Sound, while the Interior and the eastern half of the
North Slope is under a ridge. The low will move to the north
tonight, allowing for the ridge to build to the west and
strengthen. A shortwave will move from east to west along the
south side of the ridge on Saturday. At this point, there are
still some differences in how the models are handling this.
Central and Eastern Interior: A stalled front associated with a
low over Kotzebue Sound currently stretches along a line from
Arctic Village to Northway. A weak easterly wave is currently
moving over the southeastern Interior. The combination of the two
is currently serving as a forcing mechanism for thunderstorms.
We expect scatted thunderstorms along the line with some isolated
thunderstorms elsewhere across the Interior. Temperatures
tomorrow will be warmer than today for most locations with the
typical afternoon showers and thunderstorms (with the best chances
for thunderstorms east of Fairbanks). An easterly wave will move
across the southern Interior on Saturday bringing showers and
thunderstorms. The models differ on the timing and strength of
this feature at the moment, which introduces some uncertainty
into the temperature forecast for Saturday.
North Slope and Brooks Range: Scattered thunderstorms are expected
this evening along a stalled from that stretches over the eastern
Brooks Range and the eastern half of the Arctic Plain. As the
upper low moves to the north on Friday, expect scattered showers
over the Brooks Range along with some isolated thunderstorms. Some
high resolution guidance, such as the HRRR is suggesting that
thunderstorms could make it as far north as the coast on Friday.
West Coast and Western Interior: Showers along with a few
isolated thunderstorms will continue under an upper low that is
currently over Kotzebue Sound. The best chances for showers
tonight will be in the Kobuk and Noatak Valleys. The low will
slowly drift to the north tonight and Friday. Low stratus and fog
will persist tonight for the Bering Strait and for St. Lawrence
Island. A gradual warmup moves in on Saturday as interior ridging
builds inland from the east.
Coastal Hazard Potential Days 3 and 4...None.
&&
.FIRE WEATHER...
Scatted thunderstorms will develop this evening along a stalled
front in the eastern Interior, mainly along a line from Northway
to Arctic Village. Widely scattered thunderstorms are expected
for the Fortymile Country on Friday. Easterly flow aloft will
help ignite more active afternoon thunderstorms across the Alaska
Range north to the White Mountains and Tanana Valley on Saturday.
Otherwise, the warmest and driest conditions through the weekend
are expected over the Yukon Flats, where temperatures will rise
into the 80s.
&&
.HYDROLOGY...No major concerns at the moment. It is possible that
if a individual thunderstorm cell remains stationary for a while
it may produce enough precipitation to cause a rapid rise in a
small stream. This would be most likely in areas of steep terrain,
such as the Alaska Range.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
JUN 20
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1035 PM EDT Thu Jun 11 2020
.SYNOPSIS...
A cold front will continue to move east of New England,
as a much drier airmass will be ushered in tonight. Another cold
front will move across the region Friday afternoon and evening
bringing in a cooler airmass for the upcoming weekend.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1033 pm EDT...Some isolated to scattered showers will
continue to until about midnight for the southern Taconics and
Litchfield County, as the cold front and dewpoint boundary is
slowly pressing south/southeast into the mid Hudson Valley,
southern Taconics and northwest CT. The last few runs of the
3-km HRRR were a bit faster moving these showers out. We have
not observed any thunder, but a localized half an inch to a inch
of rain is possible based on the latest MRMS pcpn data.
Dewpts continue to fall into the 50s to lower 60s in the wake
of the boundary (some upper 40s in the Adirondacks). Overall,
dry wx is expected for the rest of the region for the overnight
period with subsidence in the wake of the boundary. The skies
have become clear or mostly clear north and west of the Capital
Region. The air mass is much drier with the 00Z KALY sounding having
a PWAT of 0.86" compared to the 2.07" from this morning. We did
add some patchy fog across southern VT especially east of the
southern Green Mtns.
Overnight lows will be 10 to 15+ degrees cooler than last night
with some upper 40s over the southern Adirondacks and mainly 50s
across the rest of the region. The winds will go light to calm
as high pressure ridges in from the OH Valley.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
The region will remain under a trough which will deepen as
short wave energy dives in out of central Canada. A secondary
reinforcing cold front will cross the region Friday afternoon
and evening. The airmass in place will be quite dry so just some
isolated showers are possible. What will be notable is the
cooler airmass which is ushered in with its passage for the
weekend. Mainly fair weather is expected on Saturday but with
trough over the region and short waves moves through have
slight chance pops for showers.
Dew points are expected to drop down in the 40s to lower 50s on
Friday making for more comfortable conditions. Expecting highs
in the lower/mid 80s in the Hudson Valley from the Poughkeepsie
area into the Capital District with 60s across the southern
Adirondacks and highest terrain of the eastern Catskills and
southern Greens with 70s elsewhere. Highs Saturday are expected
to be 10 degrees cooler.
Lows are expected to be in the 40s to lower 50s both Friday and
Saturday nights with some cooler upper 30s across the southern
Adirondacks Friday night.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Global models continue to trend drier through the long term period,
though, forecast confidence remains low.
At upper levels, two low pressure systems embedded in the upper
level trough are progged to split, with one ejecting to the
northeast on Sunday, and the other getting pushed to our south. The
second low is expected to become cut off across the southeast CONUS
with upper ridging building into the region. This would result in
mainly dry weather through much of the work week as ridging
strengthens. The main question is how far south the closed low
tracks as pieces of energy could ride overtop the closed low and
spark showers at times throughout the week. With both the GFS/ECMWF
trending drier, have lowered PoPs from the ER model blend.
There is more confidence in temperatures gradually warming into the
mid and upper 80s by the end of the week but sky cover is also in
question depending on the position of the low.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A cold front will move across New England early this evening.
High pressure will ridge in from the Ohio Valley and West
Virginia overnight. A secondary cold front will approach from
the St Lawrence River Valley with some some clouds, but very
little low-level moisture with it, as the best chance of an
isolated shower will be west of the Hudson River Valley.
VFR conditions are expected most of the next 24 hrs ending
00Z/SAT for KGFL/KALB/KPOU/KPSF. The skies are clearing in the
wake of the cold front early this evening, except near KPOU
where the front should move through between 01Z-03Z. Some recent
wet ground from the showers, light to calm winds and clearing
skies may allow for some patchy ground fog to form at KPSF
between 08Z-12Z/FRI. We placed some MVFR mist in. KGFL has a
chance for some patchy radiational mist overnight too, but we
left out of the TAFs for now. The skies will clear at KPOU-
KALB-KGFL with the winds becoming light and variable at 4 kts
or less.
In the late morning into the afternoon, expect some sct-bkn
diurnal cumulus to form and possibly some mid level clouds ahead
of the front. The cloud bases will be around 5 kft AGL. The
clouds should thin in the late afternoon with the frontal
passage.
The winds will be increasing from the south to southwest at
5-10 kts in the late morning, and then veer to west to southwest
at 8-14 kts in the afternoon with some gusts around 20 kts at
KALB/KGFL/KPSF.
Outlook...
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: Low Operational Impact. Slight Chance of SHRA.
Sunday: Moderate Operational Impact. Chance of SHRA.
Sunday Night: Low Operational Impact. Slight Chance of SHRA.
Monday: Moderate Operational Impact. Chance of SHRA.
Monday Night: Low Operational Impact. NO SIG WX.
Tuesday: Low Operational Impact. Slight Chance of SHRA.
&&
.FIRE WEATHER...
A much drier airmass will be ushered in tonight. Another cold
front will move across the region Friday afternoon and evening
ushering in a cooler airmass for the weekend.
Minimum RH values are expected to be 35 to 45 percent Friday
afternoon and in the upper 30s to upper 40s Saturday afternoon.
&&
.HYDROLOGY...
The rainfall was much needed across the area. Rainfall totals
ranged from a quarter of an inch up to almost 2 inches. A Public
Information Statement was issued and a map of the rainfall was
posted and tweeted on social media.
Mainly fair weather is expected over the next several days.
There could some isolated to scattered with any QPF being
minimal.
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...IAA/Wasula
NEAR TERM...Wasula
SHORT TERM...IAA
LONG TERM...JLV
AVIATION...Wasula
FIRE WEATHER...IAA
HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service Columbia SC
1020 PM EDT Thu Jun 11 2020
.SYNOPSIS...
A cold front will remain over the forecast area tonight and
near the I-95 corridor through the weekend. The chance for
showers and thunderstorms will continue with the highest chance
across the eastern Midlands. Unsettled weather is expected
through the middle of next week as an upper low stall over the
eastern states.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A line of thunderstorms near the NC/SC state line is expected to
drift slowly southward overnight. The HRRR has been persistent
over the past several runs that the thunderstorms will diminish
overnight. Though perhaps not before entering the northern-
most counties in the county warning area (CWA). Heavy rain from
these slow moving storms will still be possible in Chesterfield
and Lancaster counties and supports continuing the Flash Flood
Watch. Any showers and thunderstorms that linger into early
Friday morning should be isolated and generally in the eastern
CWA. Low temperatures tonight will range from the mid 60s west
to lower 70s east. Widespread fog potential is low due to
mixing.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Friday and Friday Night: The cold front will become nearly
stationary along the I-95 corridor on Friday and linger through
Friday night. Precipitable water values will remain high, around
1.75 to 2.00 inches, near the front, but drop off considerably
closer to 1 inch across the western portion of the forecast area
as drier air advects in within a northeasterly flow. Given the
large gradient in moisture across the area, expect a
corresponding gradient in precipitation coverage. The forecast
will indicate isolated showers and thunderstorms north/west of
I-20, scattered coverage farther south/east, with numerous
coverage near the I-95 corridor, where locally heavy rainfall is
possible. Cloud cover and the cooler northeast flow will keep
temperatures down a bit, with highs in the mid 80s most areas.
Nighttime lows will be in the mid to upper 60s.
Saturday and Saturday Night: The nearly stationary front will
shift a bit closer to the coast on Saturday, with a drier
northeast flow in place across much of the area. Isolated to
scattered showers and thunderstorms are possible, but the
greatest coverage should be across the eastern Midlands in
closer proximity to the front. Despite the northeast flow, more
sunshine should result in warmer temperatures, with highs in the
mid to upper 80s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
A closed upper level low will drop southeast out of the Ohio
Valley late in the weekend, with the stalled front retreating
inland as a warm front, moving across the area late Sunday and Sunday
night. This will result in scattered showers and thunderstorms
on Sunday with numerous showers and thunderstorms possible
Sunday night across the northern Midlands with enhanced
convergence along the front. The closed upper low will settle
over the southern Appalachians and Carolinas through the middle
of next week, resulting in unsettled conditions and cooler than
normal temperatures during that time. The upper low finally
begins to lift northward late in the week, with drier conditions
expected.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Front remains stalled out across the region, and it will remain
into Friday. Local radar showing much of the shower/storm
activity that had been across the eastern Midlands has
diminished significantly. Will keep all sites dry at this point
overnight, but will monitor for any redevelopment later.
Convective models do hint at some activity moving in from the
north late tonight, possibly impacting Midlands sites of
cae/cub/ogb, but confidence in that scenario remains low.
Plenty of cloud cover across the eastern Midlands associated
with prior rainfall. High pwat values remain across the extreme
eastern Midlands/CSRA, while drier air resides across the
western Midlands and CSRA. This will affect cloud conditions and
potential overnight. Higher confidence in lower mvfr/ifr
ceilings late tonight at ogb due to previous rainfall and higher
moisture content. Lower confidence at other taf locations due to
model inconsistencies and lower moisture. Can not rule out a
period of mvfr ceilings at all other locations towards morning.
Stratus remains preferred over fog due to a 20 knot low level
jet after 06Z. Winds will become southeasterly tonight and
northeasterly by 12Z Friday morning, remaining northeasterly
through the day. Another round of showers/storms possible across
the eastern Midlands again late Friday morning into the
afternoon.
EXTENDED AVIATION OUTLOOK...A stalled front will remain in the
area into the weekend. Early morning ceilings and visibility
restrictions will be possible with mainly diurnal convection.
&&
.EQUIPMENT...
The Columbia SC (KCAE) WSR-88D Weather Radar will be out of
service from June 12th to June 19th, 2020. This is due to
necessary generator upgrades and other maintenance as part of
the Service Life Extension Program (SLEP). During this outage,
data is available from adjacent WSR-88D radars at Greenville-
Spartanburg SC (KGSP), Charleston SC (KCLX), Wilmington NC
(KLTX) and Warner-Robbins AFB GA (KJGX). For additional details,
see our web page at www.weather.gov/cae
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Flash Flood Watch until 6 AM EDT Friday for SCZ016-116.
&&
$$
Area Forecast Discussion
National Weather Service Quad Cities IA IL
622 PM CDT Thu Jun 11 2020
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 214 PM CDT Thu Jun 11 2020
A gorgeous late Spring day was playing out across the Midwest after
a busy past few days of dealing with tropical moisture remnants. 18z
surface analysis showed sprawling surface high pressure centered
from central Colorado to western Arkansas, with northwest flow in
place across the Midwest. KDVN radar was mainly quiet, although some
isolated rain showers were not too far away to the north near KARX,
which were being driven by a weak upper level impulse moving across
southeast Minnesota and southwest Wisconsin. Temperatures as of 2 Pm
ranged from 76 in Freeport to 82 in Muscatine.
&&
.SHORT TERM...(This Evening through Friday)
ISSUED AT 214 PM CDT Thu Jun 11 2020
Key Message:
1) Other than a slight chance of an PM rain shower/sprinkle, dry
condtions will prevail for the rest of the work week with near to
below normal temperatures.
Discussion.
The aforementioned high pressure centered across the lower
Mississippi River Valley will slowly progress towards the southwest
portions of the Ohio River Valley over the next 24 hours, and will
continue to be the primary influence on our weather. The majority of
the period will see partly to mostly clear skies with some diurnally
driven Cu. Temperatures will be seasonable, with lows tonight in
the mid to upper 50s, and afternoon highs Friday in the upper 70s
to low 80s.
Like today, some guidance including the GFS, HRRR and NAMnest
attempt to fire some scattered sprinkles/rain showers Friday
afternoon over northwest Illinois as a shortwave rounding an upper
level low moves across southeast Wisconsin. However, dry sounding
profiles and best forcing remaining out of the area favors mainly
dry conditions, hence only a slight chance for now.
.LONG TERM...(Friday Night through Thursday)
ISSUED AT 214 PM CDT Thu Jun 11 2020
Key Messages:
1) Beautiful weekend shaping up with comfortable condtions Saturday;
slightly warmer Sunday.
2) Other than a slight chance of rain/storms Monday, mainly dry
and very warm weather is forecast for the remainder of the long
term period.
Discussion.
Friday Night through Saturday...
High pressure building into the upper Mississippi River Valley will
usher a backdoor cold front across the area from east to west Friday
night, and will stall just to the west of the Mississippi River
Saturday. Conditions should be mainly dry as it passes with little
in the way of vertical moisture and forcing to work with.
However, I can`t rule out a sprinkle or two, especially during the
early morning.
This front will set the stage for a picture-perfect start to the
weekend as easterly flow advects surface dewpoints in the mid
40s/low 50s and 925-850 hPa temps around 5-10 C into the area.
Afternoon highs ranging from near 70 in northwest Illinois, to the
upper 70s in northeast Missouri are forecast Saturday with a mix of
sun and clouds. Perfect to do just about anything outdoors or to
even keep the window open!
Sunday...
High pressure remains in control with another great day expected.
Temperatures will be slightly warmer as increasing southerly flow
aloft begins advecting warmer temperatures back into the area.
Currently have afternoon highs advertised in the mid to upper 70s.
Dewpoints will remain comfortable in the low to mid 50s.
Monday...
Deterministic guidance trending towards an omega-like blocking
pattern establishing itself from the southern Great Plains to the
upper Mississippi River Valley to start the week. This will
effectively push low and mid level ridging across the area, with 950-
850 hPa temps progged to climb back into the 20-25 C range by late
in the day into the overnight. Surface temps will respond, with
afternoon highs forecast to climb to near 80 to the lower 80s.
With the arrival of the warm air will come a chance for
showers/storms. GFS/ECMWF starting to agree on development of
precipitation along an elevated warm front/LLJ across central and
east central IA Monday morning, which may potentially linger into
the early afternoon before diminishing with the passage of the front.
Tuesday on...
Blended guidance favors dry condtions for the remainder of the long
term with very warm and humid conditions persisting underneath
the ridging. Daily highs are progged in the upper 80s to lower 90s
by Wednesday, with overnight lows in the upper 60s to near 70.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
ISSUED AT 621 PM CDT Thu Jun 11 2020
VFR conditions will be the rule for all terminals over the next
24 hours. Winds will be generally under 10 kts, from the
northwest.
&&
.HYDROLOGY...
Issued at 1118 AM CDT Thu Jun 11 2020
Quiet weather through next week means that routed flow will be
the main concern in river forecasting. In the next day or so, we
should have a much better idea of this routed flow and thus better
forecasts for crests into next week.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...Speck
SHORT TERM...Speck
LONG TERM...Speck
AVIATION...Ervin
HYDROLOGY...Gibbs
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
628 PM CDT Thu Jun 11 2020
.SHORT TERM...(This evening through Friday)
Issued at 257 PM CDT Thu Jun 11 2020
Clear skies and relatively light winds will continue this afternoon,
and into tonight across the forecast area. A weak surface boundary
stretches from near Dodge City up through far southern Nebraska.
Winds are generally westerly north of this boundary and more
southerly to the south of it, but otherwise isn`t impacting the
weather in the local area. The HRRR shows some thunderstorms
developing near this front this evening, but this should occur
well south of our forecast area.
Southeast winds start will increase a bit Saturday as surface high
starts to shift east the pressure gradient tightens over the local
area. That being said, we are talking about 15-25 MPH
gusts, nowhere near the winds that we saw earlier this week. A
warming trend will also start as an upper ridge amplifies
overhead. Temperatures are forecast to be a couple degrees warmer
than today in most spots with highs in the upper 80s and low 90s.
.LONG TERM...(Friday night through Thursday)
Issued at 257 PM CDT Thu Jun 11 2020
Hot and dry is the main story with this forecast. Most global
deterministic models and ensembles are showing little (if any)
precipitation through the next 7 days.
The ridge axis will shift overhead Saturday into Sunday, pushing
temperatures into the mid 90s to low 100s for most of the area. This
will also be coupled with increasingly gusty southeasterly winds.
Gusts to around 35 MPH are expected on Sunday. Chances for
precipitation are very low during this period. The only opportunity
for rain would be from High Plains convection moving in overnight,
but locally dry air will make this very unlikely. This dry air will
keep heat indices below heat advisory criteria through the
weekend.
The trough will be deamplified and pushed farther east Monday into
Tuesday as troughing moves into the northwestern CONUS. This will
lead way to more southwesterly winds at the surface, and highs are
still forecast to reach the mid 90s and low 100s. There is a very
small chance for isolated thunderstorms Monday as as a front
tries to approach from the northwest. Even if these develop, the
vast majority will still stay dry, so these chances remain far
too low to include in the forecast.
Next Wednesday is forecast to be the hottest day of the stretch, and
most of the area will push into the upper 90s and make a run at 100
degrees. The passage of a front and increasingly zonal flow will
then hopefully bring us some relief from in the form of rain chances
and cooler temperatures next Thursday through the following
weekend.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday)
Issued at 626 PM CDT Thu Jun 11 2020
Skies are expected to be clear through the period. Light and
somewhat variable winds are expected through the night and into
Friday morning, before increasing from the east during the
afternoon.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...Mangels
LONG TERM...Mangels
AVIATION...JCB
Area Forecast Discussion
National Weather Service Goodland KS
535 PM MDT Thu Jun 11 2020
.SHORT TERM...(This afternoon through Friday Night)
Issued at 1216 AM MDT Thu Jun 11 2020
18Z Water vapor imagery and RAP analysis indicated CWA on eastern
portion of large H5 ridge centered over the northern Rockies. Large
area of drying/subsidence was noted moving into the area. At the
surface a trough was draped from southeast Colorado into central
Nebraska. Not much of an airmass difference was noted across it in
the Goodland CWA, although trough did mark the separation of
strong southerly winds and much lighter conditions.
For tonight...Any potential instability/thunderstorms will be to
the south of the area where more intense heating and a narrow
plume of higher dewpoints will be present. Given the northerly
flow aloft, any storms that form here will not be heading towards
the area. as a result expect clear skies and light winds to allow
temperatures to drop into the low 50s at most locations and would
not be shocked to see a few spots in the 40s in western zones.
Friday-Friday Night...Upper level ridge will amplify and move to
the east through the period, with strong subsidence and warming
temperatures expected. Winds will shift to an easterly direction
and increase in response to cyclogenesis over the Rockies. Some
small potential for thunderstorms as instability axis will develop
south of Interstate 70. Despite weakening CINH and instability, lack
of persistent strong convergence and overall subsidence leads me
to doubt that cap will be overcome and think continued dry
forecast is warranted. Temps will return to the 90s on Friday and
with increased winds may see conditions get close to Red Flag
thresholds. For the time being it looks like conditions will not
be met, but will have to keep an eye on it.
.LONG TERM...(Saturday through Thursday)
Issued at 154 PM MDT Thu Jun 11 2020
Through early next week, will see southwest flow aloft between a
ridge axis to the east and an upper low over the northern Rockies.
While thunderstorm chances will be low, cannot rule out an
isolated afternoon or evening storm developing along persistent
lee trough at the surface and synoptic forcing with any weak
embedded shortwave aloft. The environment will be hot and dry, so
storms will be high based with little precipitation reaching the
ground, and potentially gusty winds. Starting Tuesday and through
the end of the period, the upper ridge will retrograde/rebuild
further west, though ECMWF weaker compared to the GFS. In fact,
with the ridge further south, the ECMWF allows a weak cold front
to slip into the area and a shortwave trough comes over the ridge
with a chance of showers/thunderstorms on Thursday. No sign of
this in the GFS, so will leave it dry for now.
The other concern during this period will be fire weather. Fuels
have dried enough in Kansas so that they are now considered
susceptible to wild fires, in addition to Colorado. Relative
humidity will drop to 15-20 percent every afternoon in the long
term period with temperatures reaching the 90s to near 100. As a
result, wind speeds will discriminate elevated from critical fire
weather days. On Saturday winds will be marginal, on Sunday it
appears critical conditions may be met with slightly higher wind
speeds, on Monday and Tuesday winds are currently forecast to be
light and only slightly higher on Wednesday and Thursday which
appear marginal at best for critical.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 535 PM MDT Thu Jun 11 2020
VFR conditions will present for both terminals during the forecast
period. For winds, KGLD will see northerly winds around 10kts
thru 03z-04z Friday, then light/variable. By 16z, SE 10-20kts.
For KMCK, NNE around 10kts thru 04z Friday, then light/variable.
By 16z, ESE 10-15kts.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...024
AVIATION...JN
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1023 PM EDT Thu Jun 11 2020
.SYNOPSIS...
Drier air will filter in behind a cold front and seasonably
pleasant weather will be in store for Friday and Saturday. The
front moves back west on Sunday as a wave of low pressure forms
along it then stalls. Unsettled weather sets up shop in our area
for the first half of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 1010 PM: A weak frontal boundary is stretched out just south
of I-85 across the CWA, and this will settle slowly southward
thru the remainder of the area this evening. Convective activity
has continued to congeal across central NC, building westward
to the Stanly/Cabarrus border in the last hour. This band is
beginning to push into Union NC, with combined front/outflow
boundary extending west to eastern York Co. TCLT returns indicate
the outflow is starting to edge out from under the precip core,
and trends in recent HRRR runs suggest that will be the
beginning of the end of that activity. Nevertheless, torrential
rain is expected in the next hr or two over much of Union
County, where we have a seemingly expertly placed Flash Flood
Watch (props to the previous shift). Still could see a bit more
back-building into the eastern Upstate or far southern Meck in
the same timeframe. Large DCAPE exceeding 1000 J/kg implies some
risk of a damaging microburst with the more vigorous activity,
in addition to the heavy rain threat.
Meanwhile, a 500 mb trough axis will continue to sharpen up along or
just west of the southern Appalachians tonight through Friday. This
may further slow the eastward progress of the frontal zone. The
Flash Flood Watch may be cancelled prior to its expiration at
6 AM. Between light easterly upslope flow behind the front, and
upper DPVA from the west, increasing cloud cover is expected, and a
stray shower can`t be totally ruled out. Northeasterly flow should
finally bring better boundary layer drying in the early morning,
lasting through Friday. Max temps will run 1 to 2 categories cooler
on Friday afternoon, and dewpoints may advect/mix into the 50s in
many locations, with plenty of high mountain 40s expected.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 225 PM EDT Thursday: The short-term fcst picks up at 00z
on Saturday with heights falling across the fcst area as broad
upper trofing digs down over the Eastern CONUS. The upper trof
deepens thru the period as a series of shortwaves rotate thru
the larger trof. At the sfc, a stalled-out frontal boundary will
still be lingering to our east and south with very broad Canadian
high pressure centered well to our NW. The high will gradually
shift SE thru the period, keeping NLY to NELY low-lvl flow over
the area thru most of the period. By the end of the period late
Sunday, the models try to develop a weak wedge east of the
Appalachians, but it is not expected to become very well-defined.
Overall, Saturday has been trending drier with just a slight chance
for convection over our NE zones. With deeper moisture spreading
over the area on Sunday, the chances for sct to widespread showers
and thunderstorms increase considerably, especially over the NE
zones. Saturday temps will likely be just below climatology and
Sunday temps will be a few degrees cooler than Saturday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 215 PM EDT Thursday: The extended fcst picks up at 00z on
Monday with an upper low closing off over the Ohio Valley while
steep upper ridging persists over the Central CONUS. The long
range guidance continues to keep this upper low nearly stationary
just to our north thru at least mid-week. The latest GFS tries
to open the low back up by late Wednesday as it drifts over the
Atlantic Coast, but then stalls the system again over the coast.
The ECMWF keeps the low closed and farther west thru the end of
the period. At the sfc, broad Canadian high pressure will be in
place well to our north as the period begins. The ECMWF has another
wave of low pressure develop on the stalled frontal bndy and keeps
it nearly stationary allowing a moist ELY flow with widespread
precip over the area thru most of the period. The GFS, on the other
hand, moves the low NE on Tues and Wed with little in the way of
widespread precip on both days. As for the sensible fcst, I continue
to use a model blend which gives solid chance to likely PoP over
our eastern zones and slight to solid chance over our western zones.
Temps have been trending a bit cooler for much of the period, with
values below normal thru Wednesday and near-normal temps by the
end of the period.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Front will settle past KAND later this
evening, leaving northerly flow at all sites for the period.
This flow will veer into NE quadrant late tonight or Friday.
Patchy VFR clouds persist across the area, and development of
easterly midlevel flow north of the front will lead to cig
development around 035-060. Dissipating clouds in the morning
with the few bases that remain being at VFR level.
Outlook: Expect dry/VFR weather to continue through Saturday. Then,
moisture slowly returns with chances of mainly diurnal convection
Sunday through early next week.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Flash Flood Watch until 6 AM EDT Friday for NCZ082.
SC...None.
&&
$$
SYNOPSIS...CAC
NEAR TERM...HG/08
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...08
Area Forecast Discussion
National Weather Service Paducah KY
647 PM CDT Thu Jun 11 2020
.SHORT TERM...(Tonight through Saturday night)
Issued at 239 PM CDT Thu Jun 11 2020
Dry weather will continue through at least Saturday night. A mid-
level ridge will build eastward into the area tonight and Friday,
which will allow for a nice warm up to slightly above normal
levels. Highs in the upper 80s will be common. After that, the
upper pattern will amplify with the trough pushing the ridge back
to our west. This will result in dry and cool surface high
pressure reasserting itself over our region for the first half of
the weekend. Highs Saturday will be a few degrees below normal
and lows Saturday night will be 7 or 8 degrees below normal.
.LONG TERM...(Sunday through Thursday)
Issued at 239 PM CDT Thu Jun 11 2020
Models show a mid/upper level trof to our east and a mid/upper level
ridge to our west from Sunday through mid week. The ridge makes
very little progress east due to a cutoff low developing in this
trof. The low will roam around over the east central and southeast
U.S., or just off the east coast, through the week. This pattern
keeps the PAH forecast area dry, and with northerly flow aloft, dry
air will keeps skies clear to partly cloudy.
At the surface, north to northeast flow will persist through
Tuesday. This will only allow temperatures to moderate a few
degrees, going from highs in the middle 70s to near 80 degrees
Sunday, to seasonal readings in the middle 80s by Tuesday. Humidity
levels will remain quite low, with dew points in the middle 40s to
around 50 degrees on Sunday, moderating to the middle 50s by
Tuesday. Overnight lows Sunday night will be 8 to 10 degrees below
normal in the lower to middle 50s, with lows Monday night in the
middle 50s.
By Tuesday night into Wednesday, a surface low over the Central
Plains and a surface high over the northeast U.S. will shift our
winds back to the south to southwest. This warm southerly flow will
push high temperatures into the upper 80s by Wednesday and the lower
90s by Thursday. Dew points will also gradually creep upwards, with
readings in the lower 60s by Thursday. This is still pretty
comfortable for mid June. Overnight lows will also be trending
upward, will lows near normal by Wednesday night in the middle 60s.
&&
.AVIATION...
Issued at 646 PM CDT Thu Jun 11 2020
VFR forecast for the 00z Friday WFO PAH TAF issuance. Some
question of whether parcel moisture will be sufficient for Few or
Scattered cloud bases around 6-10kft AGL across most of the TAF
sites. RH values at this level barely reach 60 percent during the
day on Friday. Moisture trajectories at this point don`t support
much in the way of lower cloud decks at this time. Good mixing and
moisture transport may have taken away alot of boundary layer
moisture yesterday and today.
For now, have gone with cloud bases near cirrus level, this is in
line with a majority of NWS offices. The NAM and RAP guidance do
bring some moisture in the 2.5-3km AGL level toward the KCGI/KPAH
TAF sites near 00z Saturday, but would like to see some
continuity before introducing cloud bases again with the 06z
Friday TAFs.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...DRS
LONG TERM...RST
AVIATION...Smith
Area Forecast Discussion
National Weather Service Blacksburg VA
740 PM EDT Thu Jun 11 2020
.SYNOPSIS...
For the weekend, an upper level trough of Low pressure over
eastern Canada will gradually move south through the Great Lakes
and Ohio Valley, bringing a return of moisture to the region.
This upper level trough is expected to cutoff over the eastern
United States and become nearly stationary for early next week
resulting in unsettled weather Sunday through Wednesday.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 720 PM EDT Thursday...
Made some minor adjustments in pops and weather for this
evening into tonight using the latest radar images and blended
in the HRRR and NAMnest. Adjusted temperatures for this evening
into tonight utilizing the surface obs,their trends and shaped
towards NBM tonight.
As of 210 PM EDT Thursday...
A cold front is moving across the VA/NC piedmont with scattered
showers and thunderstorms out ahead of it. Instabilities have
been restricted by cloud cover, but modest CAPE and shear enough
for a Marginal Risk for strong/severe capable of producing
damaging winds this afternoon. The front and associated
convection will move east into the coastal piedmont this
evening.
Behind the front, high pressure will bring cooler temperatures
and lower humidities to the area that will linger into the day
Friday. Today`s highs will top out in the 70s across the
mountains to upper 80s east of the Blue Ridge. Same idea
tomorrow but a few degrees cooler. The upper 60s to mid 70s dew
points the past couple of days will drop into the 50s.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 100 PM EDT Thursday...
A narrow region of high pressure will continue over the area
Friday night into early Saturday, providing for no
precipitation, less humidity, and slightly cooler conditions.
This will be short-lived. Our next cold front is expected to
arrive Saturday evening. This front will bring isolated to
scattered showers and storms to northern parts of the region by
Saturday afternoon. Additional showers will continue into
Saturday night, and increase in coverage. By Sunday, the front
is expected to be to our south, but stalled west to east across
the Carolinas.
Additionally, we are expected to see the development of a
closed area of low pressure over New York state and a shortwave
trough over the western Great Lakes region. While the NY low is
expected to head northeast and weaken, the western Great Lakes
feature is expected to head southeast into the Ohio Valley,
stall, close-off, and deepen. While the proximity of the stalled
front to the south will play a role as a focus for convection
on Sunday, the advancing upper low with its steepening lapse
rates will also help in shower and storm development.
Heading into Sunday night, models start to deviate on the exact
path this closed low will take. However, all seem in agreement
that it will be slow in heading in any one direction. This will
help keep the potential for additional showers in the forecast
Sunday night.
Temperatures during this portion of the forecast will start
near normal, but trend to readings slightly below normal.
Confidence in the above section of the forecast is moderate to
high.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 1100 AM EDT Thursday...
During this portion of the forecast, guidance is offering a
solution that places a closed upper level low pressure parked
over either the mid-Atlantic or southeast U.S. region of the
country. While this variability makes specific details tricky
given the nature of just where this upper low, and its
associated surface low will meander, a more generalized
statement is probably the best way to go at this point. With the
low parked/wobbling either over, or very near the area, there
should be daily chances of showers and some storms thanks to
both the relatively steep lapse rates that will be produced by
the system`s relative cool core aloft, and jet dynamics and
weaker shortwave troughs traversing through the cyclonic flow
around the parent low. Add in some daytime heating, and this
entire period of the forecast has the potential for daytime
showers and storms, maximized during the peak heating of the
day, and then waning heading through the evening and overnight
hours.
On a day to day basis, we`ll need to monitor where the heaviest
rains occur, potentially setting up one area of the region over
another as a candidate for localized flooding.
With expected precipitation and enhanced cloud cover,
temperatures during this portion of the forecast are expected to
average a little below normal, but with a trend towards
potentially milder numbers late in the period if the low can
make some progress east of the area.
Confidence in the above scenario is moderate.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 740 PM EDT Thursday...
A cold front continues to move east towards the Atlantic ocean
tonight. Isolated showers and thunderstorms are possible for the
next couple of hours in the southeast portion of the forecast
area. VFR conditions will continue at the TAF sites this evening
into tonight. Patchy fog is possible in the western river
valleys especially the Greenbrier valley overnight into Friday
morning. KLWB may drop to LIFR conditions Friday morning. Any
fog or low clouds will lift quickly Friday morning. VFR
conditions expected Friday afternoon.
High confidence in ceilings,visibilities and winds during the
taf period.
Extended Aviation Discussion...
Surface front is expected to remain stalled along the eastern
seaboard with main impacts to aviation confined to the piedmont
and tidewater areas into Friday night. A secondary front is
expected to cross the area Saturday, possibly associated with
showers and MVFR Cigs.
For early next week, an upper level trough of low pressure over
eastern Canada will gradually move south through the Great
Lakes and Ohio Valley, bringing a return of moisture to the
region. This upper level trough is expected to cutoff over the
eastern United States and become nearly stationary through
midweek resulting in unsettled weather Sunday through Wednesday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...RCS
NEAR TERM...KK/RCS
SHORT TERM...DS
LONG TERM...DS
AVIATION...KK/RCS