Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/02/16
Area Forecast Discussion
National Weather Service La Crosse WI
245 PM CDT FRI SEP 2 2016
.SHORT TERM...(This evening through Saturday)
Issued at 245 PM CDT Fri Sep 2 2016
Latest 19z surface analysis shows high pressure centered over
northern Wisconsin into northern Michigan. This is producing mostly
sunny skies and some diurnal cumulus clouds across the forecast
area per latest visible satellite imagery.
Tonight into Saturday...Surface/upper level ridge over the Great
Lakes Region will continue to dominate the forecast area. Light
winds and clear skies will result in patchy to areas of fog in the
Wisconsin river valley and favored locations in central Wisconsin.
The 02.12z GFS/NAM and 02.15z RAP hint at wind speeds of 15 to 20
knots at or above 300 feet. This will inhibit fog formation in the
Mississippi river and its tributaries. With surface/upper level
ridge ridge in control Saturday...the forecast area is expected to
remain dry...along with seasonable temperatures.
.LONG TERM...(Saturday night through Friday)
Issued at 245 PM CDT Fri Sep 2 2016
Sunday into Monday...Upper level ridge flattens out and
southwesterly flow aloft develops over the High Plains and the
Upper Midwest. The forecast area should remain dry Sunday...as the
02.12z GFS/NAM/ECMWF suggest lift/forcing/moisture convergence in
association with shortwave troughs embedded in the southwesterly
flow to be west of the forecast area. As upper level trough
deepens over the Rocky Mountains and surface front moves slowly
southeast Sunday night into Monday...moisture transport/convergence
begins to increase after 06z Monday across the far
northwest/western sections of the forecast area...with the
stronger low level jet/moisture transport/convergence west of the
forecast area. Have continued chances of showers/thunderstorms
mainly across western/northwest sections of the forecast area.
During this time frame...severe threat looks low as the higher
instability remains west of the forecast area and the
deterministic models show 0-3km shear around 20 knots.
The main concerns Monday night through Friday revolve around
thunderstorm chances, particularly Tuesday through Wednesday.
An upper-level longwave trough parked over the western CONUS will
place the Upper Midwest under southwesterly flow through Wednesday
night. The first in a series of shortwaves will pass by to our
northwest Monday night. Associated shower and thunderstorm activity
may sneak into our northern areas. A frontal boundary is progged to
set up from the Central High Plains extending into the Great Lakes
region on Tuesday. This quasi-stationary boundary should be the
focus for shower and thunderstorm development Tuesday and Wednesday,
aided by a strong low-level jet, ample moisture transport, and
subtle disturbances moving through aloft. Strong to severe storms
may be possible Tuesday into Wednesday, especially if the best shear
and instability line up with each other. Another concern is a
prolonged heavy rain potential, which will be dependent on how far
southeast the frontal boundary drifts on Wednesday. The upper-level
trough finally kicks eastward out of the northern Rockies by
Thursday morning, with the ECMWF continuing to be the faster
solution. This should clear our area of precipitation chances by
Thursday evening, if not sooner.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1208 PM CDT Fri Sep 2 2016
VFR conditions are expected through the TAF period. After a few to
scattered cumulus and cirrus today, mostly clear skies are
expected for the overnight. A pressure gradient develops tonight
as the high edges east. This will limit any fog development,
confining it to the Wisconsin River Valley and central Wisconsin.
&&
.ARX Watches/Warnings/Advisories...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ/MH
AVIATION...WETENKAMP
Area Forecast Discussion
National Weather Service Columbia SC
609 PM EDT FRI SEP 2 2016
.SYNOPSIS...
Tropical Storm Hermine will lift farther northeast of the forecast
area tonight. Behind Hermine, drier and cooler high pressure will
build into the region for the weekend.
&&
.NEAR TERM /THROUGH SATURDAY/...
Have followed radar trends and the HRRR for the placement of
showers ending from west to east tonight. The flood threat will
also diminish from west to east. Will maintain the high wind
warning in the central and east section through late tonight. Wind
has generally diminished below the criteria of 50-knot gusts but
based on impacts with less wind required to down some trees in the
saturated soil.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
Extended models consistent showing Hermine located near the NC/VA
coast by 12z Saturday as a 500mb ridge builds into the region by
early next week. Drier air and a return to sunshine this weekend
with temperatures slightly cooler than normals for this time of year.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Continued dry with mainly clear skies through the period as 500
mb ridge remains in control over the Southeast US. Temperatures
will slowly warm back above normal next week with highs in the
lower 90s and lows in the upper 60s to lower 70s.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
It will be windy this evening associated with Tropical Storm
Hermine. Conditions expected to improve behind the departing
cyclone overnight, with gradually decreasing wind speeds.
Followed the GFS LAMP for the timing. Also used the GFS LAMP for
the ceiling forecast. Outside of showers, mixing should limit fog.
Expect VFR conditions and light winds after 13z as the storm moves
farther northeast of the area.
EXTENDED AVIATION OUTLOOK...No impacts to aviation expected
Saturday through Tuesday.
&&
.HYDROLOGY...
Heavy rainfall associated with Hurricane Hermine will produce
significant rises on the area rivers. Total rainfall amounts of 2
to 6 inches with locally higher amounts have occurred. Although
the area river forecast points will rise significantly over the
next several days...only the North Fork of the Edisto River at
Orangeburg is expected to exceed flood stage.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...Flash Flood Watch through late tonight FOR GAZ040-063>065-077.
Wind Advisory until 2 AM EDT Saturday FOR GAZ040.
High Wind Warning until 2 AM EDT Saturday FOR GAZ063>065-077.
SC...Flash Flood Watch through late tonight FOR SCZ015-016-018-
020>022-025>031-035>038-041.
Wind Advisory until 2 AM EDT Saturday FOR SCZ015-016-018-
020>022-025-026.
High Wind Warning until 2 AM EDT Saturday FOR SCZ027>031-
035>038-041.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
HYDROLOGY...99
Area Forecast Discussion
National Weather Service Dodge City KS
215 PM CDT FRI SEP 2 2016
...Updated Long Term...
.SHORT TERM...(This evening through Saturday)
Issued at 1220 PM CDT Fri Sep 2 2016
Stratus and stratocumulus gradually eroding across the W/SW
counties early this afternoon, slowed down by rather moist upslope
SE boundary layer winds. SE winds will gust 20-25 mph at times
this afternoon, with temperatures again running several degrees
below early September normals. Shortwave trough over the Colorado
Rockies at midday is expected to generate a substantial amount of
showers and thunderstorms across eastern Colorado through 7 pm.
12z NAM suggests some of this activity will survive into the
NW/N zones tonight. Latest HRRR solution continues to forecast a
linear thunderstorm complex along the CO/KS border 5-7 pm, and
then weakens it dramatically as it tries to limp into the western
CWA this evening. Best chances of seeing a thunderstorm are
obviously across the far western counties (Hamilton, Stanton,
Morton) and kept chances conservative and isolated elsewhere
overnight as shortwave enters NW Kansas. Low stratus clouds are
expected to overspread SW KS again late tonight and Saturday
morning. With a cloudy sky by morning, and SE winds remaining
elevated, temperatures tonight will be much warmer than last
night, with lows in the 60s.
Saturday...Windy and warmer. Lee side surface cyclone in SE
Wyoming near 998 mb will yield a surface pressure gradient of
about 10 mb across SW KS during the afternoon. South winds of
20-30 mph will be common during peak heating. With 850 mb temps
climbing about 5C, expect mid to upper 80s to return. 12z NAM
forecasts a significant increase in instability Saturday
afternoon, with lifted indices to -5 and MLCAPE to near
2000 J/kg across mainly the northern zones. Given the lack of a
focusing mechanism, kept pops isolated for most zones, with most
locations remaining dry. Best opportunity for a storm still looks
to be NE zones near Hays Saturday evening, as shown by GFS.
.LONG TERM...(Saturday night through Friday)
Issued at 215 PM CDT Fri Sep 2 2016
Typical late summer will prevail throughout the long term.
SW flow aloft will persist across SW KS Sunday through Tuesday, as
Hermine stalls on the eastern seaboard and a broad trough remains
anchored across the northern Rockies. This pattern will ensure
leeside troughing on the plains each day, with strong south winds
each afternoon. Wind gusts of 30-35 mph will be common both Sunday
and Monday afternoons, and this will be the largest impact on
Labor Day holiday outdoor activities. This is a warm pattern for
Kansas, expect afternoon highs a few degrees above normal in the
upper 80s and lower 90s. Convective potential Sunday and Monday is
very limited, with most of us dry. With south winds maintaining a
moisture feed from the Gulf of Mexico, and the lee trough
persisting, a lone late day storm is possible somewhere in SW KS
each day, but most of us will not see them. With strong mixing at
night, low temperatures will also warm to well above normal
levels, near 70 by Labor Day morning.
12z ECMWF shows little in the way of temperature changes next
week, with any cooler airmasses remaining north of SW KS.
Temperatures will show little daily variation next week, with
highs in the 80s and lows in the 60s. With no obvious boundaries
to focus convection, any thunderstorms will be isolated at best.
Warm and dry...typical of September.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1200 PM CDT Fri Sep 2 2016
Stratus W/SW of GCK will dissipate this afternoon, as lee trough
strengthens across eastern Colorado. SE winds gusting 20-25 kts
this afternoon. Shortwave arrives in NW Kansas this evening, with
NAM/HRRR models developing a linear convective system along the
CO/KS line by 00z Sat. Uncertain how far this convection will
advance east into KS tonight before weakening. With low
confidence, only included VCTS at GCK/HYS tonight, with no mention
at DDC. Much higher confidence that stratus will return during the
06-12z Sat time frame, with IFR/MVFR cigs likely. Consensus of
short term models suggests IFR cigs are most likely at EHA, LBL
and GCK near 12z Sat. After 15z Sat, south winds increase sharply,
gusting near 30 kts at all airports.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 79 63 84 68 / 10 20 20 20
GCK 80 65 85 67 / 10 20 20 20
EHA 81 63 88 66 / 30 30 20 10
LBL 81 64 87 68 / 20 10 20 10
HYS 79 62 83 68 / 0 20 30 40
P28 80 62 85 68 / 0 10 10 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Turner
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
352 PM EDT FRI SEP 2 2016
.DISCUSSION...
High amplitude and increasing blocked mid level pattern will present
a forecast that`s largely of persistence throughout the upcoming
holiday weekend. Building upper ridge axis now anchored across the
Mississippi River Valley will arc northeast and into Great Lakes
over the next 24 hours. The resulting 588-590 DM upper high will
effectively remain centered across the region through the weekend,
as the extensive north-south elongated ridge pinches into the
tropical system Hermine circulating off the Mid Atlantic coast. With
surface high pressure centered over southern Ontario sustaining a
drying and increasing stable easterly flow, this pattern will
sustain an extended stretch of quiet weather into early next week.
Rapid removal of any lingering diurnal cu with the loss daytime
heating, leaving plenty of clear sky for the tonight period.
Moisture/wind profile will yield a favorable radiational cooling
environment under this open sky. The resulting nocturnal cooling
response will be solid given the existing thermal profile, with lows
pushing the upper 40s in the coldest locales. Some potential does
exist for patchy fog development in light of the favorable low level
easterly wind component working across the marine layer.
Notable growth in upper heights for Saturday will prompt a
corresponding increase in the deep layer temperature field.
Under full insolation, a moderately mixed profile will support highs
largely within the 75 to 80 degree range. Temperatures will see an
additional nudge upward for Sunday /lower 80s/ as the air mass
continues to moderate. The existing environment otherwise presents
virtually a carbon copy with plenty of sunshine and manageable
humidity levels through the day.
Labor Day continues to look promising as surface high pressure
travels eastward over the state, bringing dry conditions and warm
temperatures as we peak in the lower 80s for a daytime high. Strong
southerly flow will continue to advect warm air into the area,
allowing daytime highs to peak into the mid to upper 80s early next
week. The next chance for scattered showers and thunderstorms will
return Wednesday into Friday.
&&
.MARINE...
Surface high pressure will build into the central and eastern Great
Lakes tonight. The strong surface ridging will then maintain an
influence on the marine weather throughout the holiday weekend.
Expect dry weather will relatively light easterly flow trajectorie
through Monday afternoon. Wave heights over the nearshore waters are
expected to remain 2 feet or less through early next week.
&&
.PREV DISCUSSION...
Issued at 141 PM EDT Fri SEP 2 2016
AVIATION...
Maturation and deepening of the boundary layer will lead to further
scattering of cumulus this afternoon as spacing increases between
convective cells. Expect clear skies tonight under surface high
pressure. Interestingly, model data is suggesting that a core of
modestly mixed easterlies will push through the region this evening,
after sunddown. With the high pressure firmly in control, this
appears to be more of a reflection to the lowering of mixing heights
during the evening transition. HRRR data has less of a signal than
the NAM and will continue a mixed wind this evening. The structure
of the sounding tonight is not overly impressive for fog potential,
but best response may be those locations in the Tri Cities downwind
of Saginaw Bay.
For DTW...With uncertainty, will need to keep a mixed northeasterly
wind in the taf forecast throughout the evening. Models are
suggesting some potential for northeast winds to remain 7 knots or
greater through 04z tonight.
//DTW Threshold Probabilities...
* Low for cig aob 5kft
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
DISCUSSION...MR/AM
MARINE.......CB
AVIATION.....CB
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Raleigh NC
358 PM EDT FRI SEP 2 2016
.SYNOPSIS...
Tropical Storm Hermine will track northeast through eastern NC
tonight and early Saturday. High pressure will follow through early
next week.
&&
.NEAR TERM /TONIGHT/...
As of 345 PM Friday...
Tropical Storm Hermine is still on track to cross eastern NC/SC
this evening through early Saturday, passing southeast of Clinton
around midnight. The main change to the forecast has been to
reduce QPF a little, especially across the northwest.
QPF: Upstream rainfall observations have been mostly below one
inch per hour within the band extending north from the center of
Hermine, though rates are expected to intensify as the center
approaches and low/mid-level fgen is enhanced along the baroclinic
zone over the Piedmont this evening. Thus, trends in qpf suggest
rainfall totals may be a but less than projected, or at least the
rates may not be high enough for significant flash flooding and
this will be a long drawn out steady rain. The gradient will be
very tight from east to west, with some areas in the western
Piedmont seeing less than a half an inch. using WPC`s adjusted
QPF, which seems to account for the reduced QPF on the northwest
side, storm totals should range from less than a quarter inch in
the northwest Piedmont to 4-5 inches east of I-95, with the
possibility still of a relatively heavier band in the Piedmont,
which the HRRR has been indicated.
Wind: Wind reports on the western side of the the center of
Hermine have been mostly 30kt or less so far, but models continue
indicate strengthening northerly 975-925mb winds across the NC
coastal plain tonight as the center passes by, enough so that the
northern coastal plain may see a few gusts up around 40mph and
some minor impacts from downed trees.
Tornado potential: The risk of an isolated tornado will be
greatest this evening as the stronger southeasterly winds and
weak destablization arrive immediately ahead of Hermine. Much of
the southern coastal plain has continuous stabilized by light
rain today, so the warm sector will likely have a hard time
penetrating inland. The threat appears to be low at this point,
possibly near Clinton, but mostly toward the coast.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 345 PM Friday...
The center of Hermine is forecast to be over the Pamlico Sound at
12z Saturday, with its associated rainband pivoting out of the
northern coastal plain by 15z as the storm move off into the
Atlantic, per model consensus. Significant slowly of the system is
expected as it begins wrapped up into the upper trough and stuck
beneath the northern Atlantic ridge. Some guidance has been
indicating a continued chance of rain northeast of RWI, but latest
guidance indicates the wrap around moisture will be further
northeast and yield only partly cloud skies.
There will likely be some continued gusts on the back side of the
storm, mainly over the eastern piedmont and coastal plain,
especially as clouds begin to break and mixing taps into 30-40kt
of northerly flow. These gusts will slowly subside from west to
east during the afternoon, with an otherwise nice day. Dry
adiabatic mixing to 950mb suggests highs in the low to mid 80s,
though with mixing forecast to be a little lower, will keep highs
in the upper 70s and lower 80s.
contemplated the potential for fog Saturday night with light wind
and lows dipping to near the upper 50s/lower 60s dewpoints, but
there isn`t much support from guidance. Lows - 60-64
Hermine will be very slowly easing to the NE away from the northern
Outer Banks during this time, although the lingering cyclonic
circulation and trailing weak upper trough extending ESE of the mid
level reflection may yield some mid cloudiness and a period of
partly to mostly cloudy skies particularly across the north and
northeast CWA. Otherwise, a stabilizing and drying column with
recovering heights aloft and encroaching ridging at the surface will
mean dry and quiet weather with diminishing winds. Expect lows Sat
night and Sun night in the lower to mid 60s, with highs Sun from the
upper 70s NE to the mid 80s SW, where thicknesses will be easing
back to near or above normal. -GIH
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 355 PM Friday...
Dry and progressively warmer, with a lingering NRLY breeze over the
NE Piedmont and NRN Coastal Plain Sun-Mon.
The models are relatively consistent with their handling of a
shortwave trough now over central IN, which they forecast to
separate from a larger-scale positive tilt trough extending across
the NERN U.S., and subsequently capture/merge with Hermine along the
Middle Atlantic coast. Around that associated circulation, cyclonic
flow aloft will linger over central NC through early next week. Mid
level ridging is otherwise forecast to expand from the lower MS
valley NEWD across the SRN Appalachians and Carolinas through mid to
late week.
At the surface, cP high pressure now centered over the Great Lakes --
and which is responsible for surface dewpoints in the 50s as far
south as VA today-- will ridge SWD through the Appalachians, and
yield similarly low surface dewpoints (in the 50s) across much of
central NC through early next week. A lee trough will then sharpen,
with warming temperatures and continued dry conditions beneath the
aforementioned mid level ridge, through the end of the forecast
period.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
As of 145 PM Friday...
At the INT/GSO terminals, MVFR ceilings will prevail this afternoon
into tonight as Tropical Cyclone Hermine tracks NE along the
Carolina coast. NE winds at 10-15 kt this afternoon will gust as
high as 30 kt late this evening (particularly during the 00-06Z time-
frame) and early tonight. As Hermine progresses NE/ENE along the NC
coast overnight, winds will back to the N at ~15 kt, with VFR
conditions returning by sunrise as a drier airmass advects into the
NW piedmont west of Hermine.
At the RDU/FAY terminals, MVFR/IFR ceilings (700-1500 ft AGL) will
prevail this afternoon into tonight as Hermine tracks NE/ENE along
the Carolina coast and moderate to occasionally heavy rain
overspreads the region. NE winds at 10-15 kt this afternoon will
increase to 15-25 knots this evening, with gusts as high as 35-45
knots possible for several hours late this evening/early tonight (00-
06Z) as Hermine passes within ~50nm of the FAY terminal while
progressing from Myrtle Beach to Cape Lookout. Winds will back to
the North at 15-20 kt with gusts to 30 kt by 12Z Sat as Hermine
progresses NE toward Manteo. VFR conditions /clearing/ are expected
to return by late morning or early afternoon as a drier airmass
advects into central NC from the north and Hermine slows down
/eventually stalling/ offshore the VA coast.
At the RWI terminal, conditions will be similar to those mentioned
above at the RDU/FAY terminals, with the exception that northerly
winds may be stronger (20-30 kt gusting to 40 kt) than at FAY/RDU
and will likely last longer, perhaps until the end of the TAF period
(15-18Z Sat) as Hermine slows in forward progress and begins to
stall offshore the VA coast.
Looking ahead: An extended period of VFR conditions is expected
Saturday afternoon through the majority of the upcoming work week as
Hermine stalls/meanders offshore the Mid-Atlantic coast, allowing a
dry N/NW flow to persist over central NC. -Vincent
&&
.HYDROLOGY...
AS OF 1105 AM FRIDAY...
The flash flood threat continues as convection associated with the
cold front which moved south across the area yesterday produced
fairly widespread significant (>0.50 inch) rainfall across the south
and east. This was well forecast, and lines up nicely with the FFA.
The extensive rain shield is similarly on track, creeping slowly
north into the southern tier of the area this morning with the trend
for progressively heavier rain continuing to move into the area and
expand north and east into tonight. The rainfall gradient is still
expected pretty much along the I-95 corridor, with 4+ inches over
the eastern areas, so the timing and amounts support no changes to
the FFA. The flash flood threat will taper off overnight and
should be limited to the northern coastal plain by sunrise Saturday.
Minor flooding on smaller streams and in low lying areas along and
east of I95 is likely to be extensive, but whether we get enough
rain to cause mainstem river flooding is still in question. At this
point it appears that while there will be significant rises, the
mainstem rivers will remain below flood stage. Heavier rain will be
in the central to lower reaches of the Tar, Neuse, and Cape Fear
basins, so while upper forecast points will easily remain below
flood stage, an unexpected extra inch of rain or a small deviation
of the heavier rain swath to the west could produce minor flooding
at downstream points, especially at Smithfield, Goldsboro, or
Tarboro.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Saturday morning for NCZ042-073>078-
083>086-088-089.
Wind Advisory until 8 AM EDT Saturday for NCZ011-028-043-078-
083>086-088-089.
Flash Flood Watch through Saturday morning for NCZ008>011-
024>028-040-041-043.
&&
$$
SYNOPSIS...BADGETT/MWS
NEAR TERM...BS
SHORT TERM...BS
LONG TERM...MWS
AVIATION...VINCENT
HYDROLOGY...MLM
Area Forecast Discussion
National Weather Service Bismarck ND
534 PM CDT FRI SEP 2 2016
.UPDATE...
Issued at 534 PM CDT Fri Sep 2 2016
Have decided to cancel the wind advisory as sustained winds and
gusts are not meeting criteria. It will remain breezy this evening
and winds may briefly be enhanced central ND into the James River
Valley as mixing stronger winds aloft down to the surface as a
weak line of showers moves through. Currently, the showers are aligned
from southwest Sioux County, to Burleigh county, and northeast to
Pierce County.
Otherwise, farther west, a cumulus field continues to develop over
eastern Montana, ahead of a cold front. Per latest HRRR, an area
of showers and thunderstorms are expected to grown this evening. The
latest HRRR shows a line of showers and thunderstorms developing
between now and 03z/10PM CDT Friday, then crossing into our
western border thereafter. The HRRR indicates that northwest ND
would be the favored area for precipitation and have adjusted
pops in this region. Rest of forecast remains on track.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 1238 PM CDT Fri Sep 2 2016
The main focus for the short term is winds and precipitation
chances.
Afternoon winds so far have remained just below Wind Advisory
criteria, with sustained speeds around 25 mph and gusts around or just
less than 40 mph. Wind speeds will diminish somewhat this evening
as diurnal heating and mixing ends. However, a tight pressure
gradient will remain over the eastern half of North Dakota and a
low level jet may intensify late tonight across east central North
Dakota. This could keep gusty winds around 30 mph through the
overnight hours for portions of the James Valley.
So far today precipitation has been rather scattered and weak.
Very little if any precipitation is reaching the ground across
western North Dakota. Latest runs of short term guidance continue
to trend dryer for this afternoon and evening and the 18z special
sounding shows a rather substantial cap. However, an upper level
shortwave trough is expected to swing through later this afternoon
and evening. This could enhance the potential for precipitation
later this afternoon and evening across central and eastern North
Dakota and will therefore keep a mention of a slight chance of
light rain showers in the forecast. There have been a few
lightning strikes from time to time and with forecast
showalter indices around -5 will keep a mention of thunderstorms
in the forecast as well.
.LONG TERM...(Saturday night through Friday)
Issued at 1238 PM CDT Fri Sep 2 2016
Possible heavy rain and severe weather will highlight the
extended forecast.
A slow moving upper level trough will impact the Northern Plains
this weekend into early next week. A moisture plume will push
precipitable water values above the 99th percentile and will
support the possibility for heavy rainfall across central and
eastern North Dakota Sunday afternoon and Sunday night. At the
same time cape and shear could be substantial enough to produce
some strong thunderstorms with large hail and damaging winds
Sunday afternoon and evening. Some uncertainty on how much surface
heating will occur if ongoing showers and thunderstorms limit the
afternoon heating, but at this time it seems plausible that some
portions of southern North Dakota will be under the threat for
strong thunderstorms.
By Monday the cold front will bring cooler and more stable air to
the region. More widespread showers are expected across the
northwest North Dakota where the strongest winds aloft will be
found.
Somewhat cooler weather is expected Tuesday through Thursday with
a chance for scattered showers and isolated thunderstorms.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 534 PM CDT Fri Sep 2 2016
A cold front will slowly move into western ND after 06z, and then
continues into the central terminals Saturday afternoon, before
stalling prior to getting into KJMS. Hence, ahead of the cold
front Friday night, expect a vcsh/vcts at KISN and possibly KDIK,
then shifting into KMOT/KBIS after 18z Saturday. Vfr cigs/vsbys
still expected with the frontal passage.
&&
.BIS Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...AC/KS
Area Forecast Discussion
National Weather Service Columbia SC
639 PM EDT FRI SEP 2 2016
.SYNOPSIS...
Tropical Storm Hermine will lift farther northeast of the forecast
area tonight. Behind Hermine, drier and cooler high pressure will
build into the region for the weekend.
&&
.NEAR TERM /THROUGH SATURDAY/...
Have followed radar trends and the HRRR for the placement of
showers ending from west to east tonight. The flood threat will
also diminish from west to east. Will maintain the high wind
warning in the central and east section through late tonight. Wind
has generally diminished below the criteria of 50-knot gusts but
based on impacts with less wind required to down some trees in the
saturated soil.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
Extended models consistent showing Hermine located near the NC/VA
coast by 12z Saturday as a 500mb ridge builds into the region by
early next week. Drier air and a return to sunshine this weekend
with temperatures slightly cooler than normals for this time of year.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Continued dry with mainly clear skies through the period as 500
mb ridge remains in control over the Southeast US. Temperatures
will slowly warm back above normal next week with highs in the
lower 90s and lows in the upper 60s to lower 70s.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
It will be windy this evening associated with Tropical Storm
Hermine. Conditions expected to improve behind the departing
cyclone overnight, with gradually decreasing wind speeds.
Followed the GFS LAMP for the timing. Also used the GFS LAMP for
the ceiling forecast. Outside of showers, mixing should limit fog.
Expect VFR conditions and light winds after 13z as the storm moves
farther northeast of the area.
EXTENDED AVIATION OUTLOOK...No impacts to aviation expected
Saturday through Tuesday.
&&
.HYDROLOGY...
Heavy rainfall associated with Hurricane Hermine will produce
significant rises on the area rivers. Total rainfall amounts of 2
to 6 inches with locally higher amounts have occurred. Although
the area river forecast points will rise significantly over the
next several days...only the North Fork of the Edisto River at
Orangeburg is expected to exceed flood stage.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...Wind Advisory until 2 AM EDT Saturday FOR GAZ040.
High Wind Warning until 2 AM EDT Saturday FOR GAZ063>065-077.
SC...Wind Advisory until 2 AM EDT Saturday FOR SCZ015-016-018-
020>022-025-026.
High Wind Warning until 2 AM EDT Saturday FOR SCZ027>031-
035>038-041.
Flash Flood Watch until 6 AM EDT Saturday FOR SCZ015-016-021-
022-027>031-035>038-041.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
HYDROLOGY...99
Area Forecast Discussion
National Weather Service Dodge City KS
551 PM CDT FRI SEP 2 2016
...Updated aviation discussion...
.SHORT TERM...(This evening through Saturday)
Issued at 1220 PM CDT Fri Sep 2 2016
Stratus and stratocumulus gradually eroding across the W/SW
counties early this afternoon, slowed down by rather moist upslope
SE boundary layer winds. SE winds will gust 20-25 mph at times
this afternoon, with temperatures again running several degrees
below early September normals. Shortwave trough over the Colorado
Rockies at midday is expected to generate a substantial amount of
showers and thunderstorms across eastern Colorado through 7 pm.
12z NAM suggests some of this activity will survive into the
NW/N zones tonight. Latest HRRR solution continues to forecast a
linear thunderstorm complex along the CO/KS border 5-7 pm, and
then weakens it dramatically as it tries to limp into the western
CWA this evening. Best chances of seeing a thunderstorm are
obviously across the far western counties (Hamilton, Stanton,
Morton) and kept chances conservative and isolated elsewhere
overnight as shortwave enters NW Kansas. Low stratus clouds are
expected to overspread SW KS again late tonight and Saturday
morning. With a cloudy sky by morning, and SE winds remaining
elevated, temperatures tonight will be much warmer than last
night, with lows in the 60s.
Saturday...Windy and warmer. Lee side surface cyclone in SE
Wyoming near 998 mb will yield a surface pressure gradient of
about 10 mb across SW KS during the afternoon. South winds of
20-30 mph will be common during peak heating. With 850 mb temps
climbing about 5C, expect mid to upper 80s to return. 12z NAM
forecasts a significant increase in instability Saturday
afternoon, with lifted indices to -5 and MLCAPE to near
2000 J/kg across mainly the northern zones. Given the lack of a
focusing mechanism, kept pops isolated for most zones, with most
locations remaining dry. Best opportunity for a storm still looks
to be NE zones near Hays Saturday evening, as shown by GFS.
.LONG TERM...(Saturday night through Friday)
Issued at 215 PM CDT Fri Sep 2 2016
Typical late summer will prevail throughout the long term.
SW flow aloft will persist across SW KS Sunday through Tuesday, as
Hermine stalls on the eastern seaboard and a broad trough remains
anchored across the northern Rockies. This pattern will ensure
leeside troughing on the plains each day, with strong south winds
each afternoon. Wind gusts of 30-35 mph will be common both Sunday
and Monday afternoons, and this will be the largest impact on
Labor Day holiday outdoor activities. This is a warm pattern for
Kansas, expect afternoon highs a few degrees above normal in the
upper 80s and lower 90s. Convective potential Sunday and Monday is
very limited, with most of us dry. With south winds maintaining a
moisture feed from the Gulf of Mexico, and the lee trough
persisting, a lone late day storm is possible somewhere in SW KS
each day, but most of us will not see them. With strong mixing at
night, low temperatures will also warm to well above normal
levels, near 70 by Labor Day morning.
12z ECMWF shows little in the way of temperature changes next
week, with any cooler airmasses remaining north of SW KS.
Temperatures will show little daily variation next week, with
highs in the 80s and lows in the 60s. With no obvious boundaries
to focus convection, any thunderstorms will be isolated at best.
Warm and dry...typical of September.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 551 PM CDT Fri Sep 2 2016
Isolated thunderstorms over eastern Colorado will move toward southwest
Kansas this evening. There is some small potential for the storms to
persist into the late evening hours and possibly impact flight operations
at Garden City but confidence in this is low at this time. MVFR to
possibly IFR cigs are expected to redevelop at Garden City and Dodge
City later tonight. Conditions should improve to VFR by mid to late
Friday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 84 68 89 / 20 20 20 20
GCK 65 85 67 91 / 20 20 20 10
EHA 63 88 66 91 / 30 20 10 20
LBL 64 87 68 92 / 10 20 10 20
HYS 62 83 68 90 / 20 20 30 20
P28 62 85 68 90 / 10 10 10 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Gerard