Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/28/17
Area Forecast Discussion
National Weather Service Albany NY
1016 PM EDT Thu Jul 27 2017
.SYNOPSIS...
Behind a departing cold front, dry weather is expected for most
of the area Friday into the weekend; however, some rainfall is
possible across far southern areas as low pressure passes by to
the south. Temperatures will remain a bit cooler than normal.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1016 PM...Ahead of a weak surface boundary, some rain
showers are still ongoing across parts of the Adirondacks and
into central and southern. Based on the 3km HRRR and radar
trends, these showers will continue to slide southeast and
weaken over the next hour or two. As the boundary continues to
wash out over the forecast area, showers will be coming to an
end by shortly after midnight or so.
The main challenge will be cloud cover/fog potential. Satellite
imagery has shown that most areas have been clearing out, which
is setting the stage for some radiational fog to develop due to
the recent rainfall and light surface winds. Some stratus clouds
may remain in place over the higher terrain which could limit
fog for those areas (such as the Adirondacks and southern VT). For
the majority of the area, have gone with partly cloudy skies
with patchy/areas fog mention. Lows tonight near to slightly
above normal in the upper 50s to mid 60s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
The main player in the forecast for Friday into the weekend will
be a vigorous, compact upper low forecast to move from the
Western Great Lakes to around the Delmarva. A surface low will
develop in the lee of the Mid-Atlantic Appalachians and slowly
expand northeastward into the Atlantic Ocean south of Cape Cod.
Models are in generally good agreement on the synoptic scale with
the progression of the upper low and area of lower surface
pressure, but still differ a bit on stronger mesoscale areas of
lower pressure developing over the waters on the weekend.
Guidance indicates potential for strong moisture advection in
association with these strong mesoscale lows, with deformation
precipitation to the north. Model consensus continues to keep
the majority of the forecast area dry during the period.
However, the northern extent of the deformation zone could
impact the mid-Hudson Valley and Northwest Connecticut Friday
night into Saturday with some showers. As of now, aside from a
few ensemble member outliers, precipitation amounts appear to be
light.
Friday appears to be a tranquil weather day for the entire
forecast area as the region remains situated between high
pressure to the northwest and the developing low to the south.
High temperatures are expected to be warmer than Thursday but
still slightly below normal. Saturday could become a bit breezy
as the low strengthens to our south, with seasonably strong
northeasterly winds developing. H850 CAA will also occur as the
low wraps cooler air in, with temps dropping to around 10C. As a
result, highs are expected to struggle to reach the mid-70s even
with good diurnal mixing outside of southern areas that see more
in the way of cloud cover and possibly some showers. Humidity
should be low for this time of year for most of the forecast
area.
A bit cooler Saturday night as the pressure gradient relaxes
somewhat, with lows mainly in the 50s (possibly some 40s up
north). Current indications are for another tranquil day Sunday
as the low becomes situated more to our south or east. Highs a
bit warmer than Saturday but still a bit below normal with low
humidity.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
At the start of the extended period, a closed off low at 500 hpa
will be situated just south of the region over the mid-Atlantic
States. This upper level low will be associated with a surface
storm located just off the New Jersey Shore and this storm will
slowly drift northeast through Tuesday.
Our region should be far enough north of these features to remain dry
for Sunday night through at least Monday night, as any precipitation
will likely only reach as far north as the New York City area and a
weak area of surface high pressure remains situated close enough to
the region. Overnight lows will mainly be in the 50s with highs
reaching into the upper 70s to low 80s for valley areas on Monday
under a partly to mostly sunny sky.
The upper level low will start to open up on Tuesday as it passes
over far eastern New England. In addition, a weak and subtle upper
level disturbance passing within the northern stream could help
allow a few showers and possibly a thunderstorm to develop on
Tuesday afternoon, mainly for northwestern parts of the area. Most
areas should continue to remain dry, with seasonable temps in the
low to mid 80s along with a partly sunny sky.
Another upper level shortwave trough will be diving towards the
Great Lakes and eventually the Northeast for the middle to latter
part of the week. The models are still unclear on the exact
strength and timing of the trough, but we will allow for slight to
low chc POPs for showers and possible thunderstorms for Wednesday
into Thursday, as this feature heads towards the area. With warmer
temps expected aloft, it should be seasonably warm with high temps
reaching into the mid 80s for most valley areas. The humidity also
looks to creep up as well, as the low-level southerly flow ahead of
the approaching shortwave trough will allow dewpoints to reach back
into the 60s.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
With a weakening frontal boundary moving across the area, the
threat for rain showers has ended. Clouds have been clearing out
and with plenty of lingering low-level moisture in place and
light to calm winds at the surface, some radiational fog will
form tonight. All sites may see some fog developing overnight, mainly
after 06Z, although there could be some patches that develop as
early as 02z-04z. Fog will lower flying conditions down to IFR
for most sites by late tonight, although the most widespread
and/or dense fog will probably be at KGFL and possibly KPSF.
Any fog/mist should dissipate by 11z-12z, allowing for VFR
conditions to return for Friday, with light winds throughout the
day. It looks to be dry, with just some passing high cirrus
clouds through the day.
Outlook...
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Low Operational Impact. Slight Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
Drier weather is expected to take hold Friday into the weekend,
although isolated to scattered showers are possible over
portions of the Mid-Hudson Valley and Northwest Connecticut. RH
values will still remain somewhat elevated Friday, only falling
into the mid-50s to mid-60s. It will be progressively drier
into Sunday, with RH values bottoming out near 40 percent by
Sunday. North-northeasterly winds could become a bit breezy on
Saturday, gusting to around 25 mph at times.
&&
.HYDROLOGY...
Rain showers will continue to diminish through this evening and
generally be on the light side.
Conditions will generally be dry Friday into the weekend, but
some periods of rainfall may impact areas around the mid-Hudson
Valley and Northwest Connecticut Friday night into Saturday.
Models continue to keep the heavier rainfall south of the
forecast area, with generally light amounts of 0.25" or less
expected. Trends will continue to be monitored as there will be
a sharp cutoff in precipitation amounts, so a slight northward
shift in the storm track could result in increased QPF totals.
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/OKeefe/Thompson
NEAR TERM...Frugis/Thompson
SHORT TERM...Thompson
LONG TERM...Frugis
AVIATION...Frugis
FIRE WEATHER...Thompson
HYDROLOGY...Thompson
Area Forecast Discussion
National Weather Service Binghamton NY
954 PM EDT Thu Jul 27 2017
.SYNOPSIS...
Isolated showers will taper off overnight in northeast PA and
south central NY. Afterwards, Friday through the weekend looks
mostly rain free, as high pressure builds down from eastern
Canada. The one exception will be parts of northeast
Pennsylvania, where showers and a few storms will occur
Saturday, across areas mainly south of Wilkes Barre and
Scranton, on the outer edges of a rare summer coastal storm
system.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
930 pm update...adjusted POPs for some residual showers that
continue to slowly press east into upstate NY and weaken. The
latest HRRR has the best handle on this weak convection relative
to the other high resolution convection allowing models. The
weak convection was forming in response to a small upper level
wave which was moving across NY at this time as seen in the
GOES-16 Water Vapor channels. The HRRR suggests this isolated
shower activity works its way into northeast PA and then falls
apart overnight. Then there will be a break before the next
shield of precipitation moves north toward northern PA Friday
morning. Water Vapor channels on the GOES-16 all show a well-
defined upper level low over northeast Minnesota. This upper
level low is projected to drop southeast tonight and Friday and
link up with a broad area of surface low pressure over the
Middle Atlantic states and form a fairly rare summer coastal low
off the mid atlantic coast by Saturday. All main synoptic
models (Euro, GFS, CMC and 80 km NAM) show that the northern
edge of the showers and storms reaches just into northeast PA by
00z Saturday with the heaviest precipitation staying well south
of northeast PA. So we have slight chance POPS from south
central NY increasing to likely POPs in our far southern zones
in the Poconos. Other than adjusting POPs tonight for the
minimal activity no major changes through Friday.
630 pm update...did a quick upate to account for the showers
forming in Steuben County and the western Finger Lakes region.
This activity was forming in advance of a small short wave
moving southeast toward NY state in the presence of the day`s
heating. This wave will pass east and the heating of the day
will wane and hence the shower activity will taper down by late
evening. I also added patchy fog into our valley late tonight
as there will be some clearing combined with a very moist
boundary layer.
230 pm update... Steadier showers continue to exit stage right
late this afternoon. Developing breaks of sunshine across the
region have allowed the atmosphere to destabilize somewhat, with
ML CAPE values of 200-500 j/kg. This, along with the approach of
a short-wave from the northern Great Lakes region, may cause
isolated-scattered showers and thunderstorms to re-develop, and
then persist into the early evening.
Later tonight, conditions should become generally rain-free,
with partly cloudy skies most areas. Given the anticipated
breaks in cloud cover and saturated ground conditions, the re-
development of lower stratus clouds and fog seem like a good
bet. Although fog can`t be ruled out anywhere, it will likely be
most dense in the river valleys of the twin tiers. Lows by
daybreak should range from the upper 50s-mid 60s.
Friday-Friday night, model trends continue to show the main
threat of heavy rainfall shifting well south and east of our
forecast area, across southern PA, NJ, and perhaps into southern
New England, in association with a sharp upper trough and
developing surface wave along the east coast. The outer
periphery of the steadier rainfall may scrape parts of NEPA,
thus we`ll continue with chance-likely probabilities for light
rain (40-60%). Farther north into CNY, rain-free weather is
foreseen.
Highs Friday will be in the 70s, with lows Friday night in the
50s-lower 60s.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
The main concern this period will continue to be monitoring closed
low south of the region that will continue to brush our
southern zones. To begin the period Saturday morning, the low
looks to be situated near the Delmarva. Heavier rain will be
affecting areas around the Jersey coast at this time with a
little light rain possibly continuing to affect NE PA into
Saturday morning, especially south of I-84. The twin tiers
region northward looks to be mainly dry but it will be close and
at this point indications are the low will at least be close
enough to bring considerable mid and high cloudiness as far
north as central NY zones and this will keep temperatures down.
Highs look to be mainly in the low to mid 70s and be accompanied
by a fairly breezy NE wind so not exactly a hot summer day.
Any lingering light rain over NE PA tapers off by late day
Saturday with clearing skies to follow for Saturday night. Lows
will be mainly in the low to mid 50s.
Sunday...high pressure looks to finally build in as the low to
the south moves away and this will bring mainly sunny skies but
continuing cooler than average temperatures for this time of
year. Highs will mostly be in the mid to upper 70s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure will continue to dominate the weather through
Monday bringing mainly clear skies with seasonal temperatures.
Lows will be in the 50s with highs generally around 80. Heading
toward the middle of next week, a disturbance moving through the
upper level flow could spark a few isolated to scattered storms
by Tuesday afternoon across central NY but otherwise mostly dry
weather looks to predominate. A cold front will then move in by
next Wednesday bringing a better chance for more widespread
showers and storms which could last into Thursday. Temperatures
will generally remain around seasonal for the long range.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
A small cluster of showers could bring a brief period of rain to
ELM through 02z and at BGM between 01z and 03z, otherwise VFR
conditions can be expected through this evening with scattered
clouds. Areas of MVFR conditions will develop after 06z with
localized IFR conditions in low clouds and fog between 08z and
12z. Conditions will improve to VFR by mid-morning. Rain over
southern Pennsylvania will move north with some showers possible
at AVP by late in the day Friday otherwise dry conditions will
hold through the day Friday farther north. Winds will be light
and variable tonight becoming northeast at 5 to 10 kts on
Friday.
Outlook...
Saturday-Monday...Outside of early morning fog (mostly KELM),
mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...DJN/MLJ
NEAR TERM...DJN/MLJ
SHORT TERM...PCF
LONG TERM...PCF
AVIATION...MLJ/MSE/TAC
Area Forecast Discussion
National Weather Service Denver/Boulder CO
652 PM MDT Thu Jul 27 2017
.UPDATE...
Issued at 652 PM MDT Thu Jul 27 2017
Increased pops for the northeast corner of Colorado where
thunderstorms are expected to move southeast into the area. These
storms are strong to severe. Large hail and damaging winds will
be possible over the northeast corner through the evening.
Elsewhere, the main threat with the storms will be heavy rain.
Airmass moist, but not as moist as yesterday. Precipitable water
value off the 00Z sounding at DNR was 1.13 vs 1.34 yesterday.
Thunderstorm coverage will be isolated to scattered.
&&
.SHORT TERM...(This evening through Friday)
Issued at 400 PM MDT Thu Jul 27 2017
An abnormally moist atmosphere trapped beneath a large upper level
high pressure will remain over Colorado/eastern Utah through at
least Friday. Based on radar and satellite imagery, convection has
been quite limited this afternoon. Only in the past hour have t-
storms begun to form over the northern Front Range and over and
around South Park. Believe the tranquility elsewhere will break in
the next hour or two. A moist southeast low-level flow on the
plains, steep 700-500mb lapse rates and the passage of a weak
disturbance in light northwest flow aloft are still expected to
generate t-storms scattered across eastern sections of the CWA
through this evening. Storms in the South Park area, of which one
has produced hail in the past several minutes, are predicted to
track east-northeast over southern portions of the I-25 corridor by
00z. This batch of storms is then projected to merge this a broken
line of t-storms swinging out of the northern foothills in the next
hour or so and then southeast across ern Larimer, Weld and Morgan
counties 00z-04z this evening. OOz/Sat RAP and NAM sfc CAPES in this
area anywhere from 1500-2500j/kg. Boundary layer shear also looks
favorable for storm formation. Where these two batches of storms
come together, best estimate in the eastern Weld, Morgan and Logan
county area, could see some storms turn severe. SPC has part of this
area in a slight risk for severe. Large hail and damaging winds main
svr threats. Slow storm motions and mean layer PWs in the 1.0 to 1.2
range could also result in heavy rainfall from a few of these cells,
with locally up to 1.5 inches in under 45 minutes. Most if not all
of this storm activity is forecast to exit to the CWA around
midnight. Could see patchy fog form again in wet low-lying areas
towards dawn. But, not as widespread as this morning.
On Friday...these same warm and humid conditions beneath the under
ridge will be in place for another round of t-storms by the
afternoon. PW values are forecast to gradually increase through the
day, setting the stage for locally heavy rainfall once again from a
slow moving storms. The formation of a Denver cycle tomorrow
afternoon could also create conditions suitable for hail in the
Denver metro area. Will need to monitor this closely tomorrow.
Otherwise, temperatures during the next 24 hours will remain below
average.
.LONG TERM...(Friday night through Thursday)
Issued at 400 PM MDT Thu Jul 27 2017
The upper ridge axis will stay right over Colorado Friday night
into Saturday. The upper ridge is to migrate westward and be over
the Great Basin by Sunday morning. There is little in the way of
any synoptic scale energy through Sunday night. The low level
winds look to stick to normal diurnal trends. Precipitable water
values remain in the 0.75 to 1.50 inch range all five periods. Dew
point readings range from the upper 40s F west to mid 60s F east
through Sunday night. There are pretty decent CAPE values over the
eastern two-thirds of the CWA Friday evening into Saturday
afternoon. The best CAPE for late day Sunday is over the far
eastern CWA. The QPf fields show pretty decent coverage of
measurable rainfall Friday evening, then again Saturday afternoon
and much of the night. Again, Sunday afternoon and evening there
is decent QPF. Will leave in or go with "likely"s in the
mountains, with "chance"s over the plains. Will also need pops in
the overnight and morning periods. For temperatures, Saturday`s
highs are 1-3 C cooler than Friday`s. Sunday`s readings are
similar to Satruday`s but a bit cooler of the northeast corner.
For the later days, Monday through Thursday, the upper ridge axis
stays west of Colorado Monday. By Tuesday and continuing through
Thursday, the upper ridge is centered over the Great Basin into
southern Idaho. There is moisture around through Tuesday night,
then it dries out Wednesday quite a bit. Temperatures stay below
seasonal normals.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 652 PM MDT Thu Jul 27 2017
Thunderstorms have struggled to survive as they move east off the
higher terrain. Still a chance the Denver airports see a
thunderstorms through 05Z. The best chance will be at KBJC and
KAPA. Skies are expected to clear some after 06Z. For Friday,
there will be another chance for thunderstorms after 21Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Meier
SHORT TERM...Baker
LONG TERM...RJK
AVIATION...Meier
Area Forecast Discussion...UPDATED
National Weather Service Caribou ME
948 PM EDT Thu Jul 27 2017
.SYNOPSIS...
A cold front will cross the region tonight with scattered
showers and isolated thunderstorms before midnight. The front
will stall along the down east coast on Friday. High pressure
will build in on the weekend bringing a sunny and dry weekend
for most areas.
&&
.NEAR TERM /THROUGH FRIDAY/...
9:30 PM Update...Forecast is in good shape, just cleaned up the
grids a little. Most of the rain showers are coming to an end
with Washington County still receiving some rainfall at this
hour. A few isolated showers for the remainder of the region,
but overall the rain is coming to an end. Very variable rainfall
amounts today with a few hundreths in some areas all the way up
to .4" tenths in isolated areas. On average most areas received
around a tenth of an inch of rainfall. Not the good soaking the
area needs, especially since the pattern is remaining dry
through the next 7 days.
6:30 PM Update...Took the enhanced wording out of the grids as
storms are relatively weak at this and should remain weak
through the evening. A stray lightning strike is still possible
as the 500mb shortwave trough and surface cold front are just
beginning to approach the Quebec/Northwoods border. Overall
shower and thunderstorm coverage will remain scattered with only
half of the area expected to get measurable precipitation
tonight.
Previous Discussion...
Some thunderstorms could have very heavy rainfall and strong
wind gusts this evening.
The latest meso-analysis showed the axis of enhanced wx shifted
further s into the Central Highlands and interior Downeast. The
cold front is shown by the latest run of the NAM12/RAP and HRRR
to slide across the state tonight. Showers and tstms will set
up. The heaviest activity looks like it will be across the
aforementioned areas which would include the Mt. Katahdin region
with heavy rainfall and strong wind gusts. There is also an
area of heavier activity shown to move through ne Aroostook
County this evening. Sounding data showed possible training of
cells which would lead to very heavy rainfall. As mentioned in
the earlier update, there is some directional & speed shear
which would allow for any stronger storms to have some rotation.
The evening crew will need to monitor things. Activity looks
like it will wind down later in the evening w/loss of diurnal
effects and best forcing pushing e. Decided to add the mention
of fog as winds will be fairly light into the morning.
For Friday, winds will pick up as the upper front apchs from
the nw and some drier air works into the region. The cold front
is expected to stall along the coast into the midday w/some
light showers lingering. Decided to keep a 20% pop for some
showers along the coast. Elsewhere, some sunshine returning
w/daytime temps in the 70s.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Strong high pressure will build in from he west Friday Night and
persist over the region Through Sunday. At the same time low
pressure will develop over the Mid-Atlantic States and pass to
the south of New England Saturday and Sunday. This system is
expected to stay far enough to the south to keep both clouds and
precipitation south of the forecast area through the weekend.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure is expected to weaken over the region on Monday
and Tuesday allowing clouds to increase, however the high should
remain strong enough for conditions to remain dry. A cold front
will then approach from the northwest Wednesday and may result
in some showers late in the day or in the evening. Another
strong area of high pressure is then expected to build in from
the northwest again on Thursday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MVFR conditions this evening for the northern
terminals w/VFR for KBGR and KBHB. Some tstms will lower
conditions to IFR briefly this evening. Looking for some fog to
develop later tonight which could allow for cigs/vsbys again to
briefly drop to MVFR/IFR. Conditions look like they will
improve to VFR for all terminals on Friday w/the exception of
KBHB as that site could see some MVFR cigs through early
afternoon.
SHORT TERM: Expect VFR conditions Saturday through Tuesday.
&&
.MARINE...
NEAR TERM: No headlines are expected through the next 24 hours.
Kept wind at 10-15 kts w/some gusts to 20 kts. Winds will drop
off later tonight as they turn to the nnw as the closes in. Seas
2-3 ft attm will build some to around 4 ft this evening. Fog
will develop later this evening and persist into Friday.
SHORT TERM: Have used the NAM to initialize wind grids through
the day sunday then transition to the Super Blend winds. With
northeasterly flow expected Saturday into Sunday, will not make
any adjustments for boundary conditions. For Waves: Expect
longer period southeasterly swell (1-2 feet/8-9 seconds) to
dominate early Saturday then northeasterly wind wave is expected
to become the primary wave system later Saturday into Sunday as
low pressure passes to the southeast. Will use the Nearshore
Wave Prediction System (NWPS) to initialize wave heights. Will
not adjust wave heights Saturday and Sunday with under
northeast flow but will lower model wave heights for the
remainder of the period due to boundary inversion induced by
relatively cold sea surface temperature.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...Hewitt/Dumont
Short Term...Mignone
Long Term...Mignone
Aviation...Hewitt/Dumont/Mignone
Marine...Hewitt/Dumont/Mignone
Area Forecast Discussion
National Weather Service Charleston SC
1045 PM EDT Thu Jul 27 2017
.SYNOPSIS...
Broad low pressure near southeast Georgia will shift northeast
tonight. A cold front will approach the area Saturday and move
through the area Saturday night. High pressure will then build
into the area from the northwest for the first part of next
week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
No significant changes were made for the rest of tonight. Latest
radar indicates that convection has ended across the area.
However, still expect isolated to scattered convection to re-
form over the Atlantic waters later tonight as the weak mid
level low center drifts up the coast. The HRRR continues to show
scattered showers/thunderstorms reaching into the coastal areas,
especially for SC late tonight/early Friday morning. Given lack
of rainfall across the area, feel fog threat it too low to
mention.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Friday: A strong mid and upper level disturbance especially for this
time of the year will shift from the Great Lakes to the Mid
Appalachian mountains during the period resulting in a increase in
mid and upper level westerly flow across the region. A weak area of
surface low pressure along the South Carolina coast early Friday
morning will shift slowly northeast along the coast and will
gradually be absorbed by a larger area of lower pressure further
north in the Mid Atlantic. Friday should be characterized by a more
typical summertime day with showers and thunderstorms most likely
along the sea breeze during the afternoon and evening hours. Rain
chances Friday should be lower than recent days, in the chance
category. Strong cyclonic flow, deep moisture and an influence from
a strengthening upper level jet should aid in upstream thunderstorm
development Friday afternoon which should propagate into mainly
northern and western areas during the first part of Friday night.
Despite the loss of heating and likely destabilization from
afternoon and evening convection, still feel that there is a decent
threat for rain chances after midnight, mainly in the north and
west. Temperatures will be fairly typical for the middle of summer,
with highs from the upper 80s near the coast to mainly the lower 90s
elsewhere and lows from the mid 70s inland to the upper 70s near the
coast.
Saturday: As a fairly decent East Coast upper trough becomes
established, a cold front will approach the area on Saturday and
then move through the area Saturday night. Increasing upper level
lift, decent low level convergence along the front, and high
moisture levels all support a likely threat for showers and
thunderstorms. Extensive cloud cover, only weak instability, and the
timing of the cold front during Saturday night should preclude the
development of severe thunderstorms. However, could not rule out a
few strong thunderstorms especially Friday evening. The high water
content of the atmosphere support the potential for areas of heavy
rainfall. The threat of showers and thunderstorms should diminish
from west to east behind the front Saturday night. Highs Friday will
be kept down by cloud cover and precipitation and should range from
the mid 80s in the north to near 90 in the south. Overnight lows
will be a bit cooler behind the cold front, ranging in the near 70
in the west and north to the mid 70s along the southeast Georgia
coast.
Sunday: Model trends support a quicker end to the threat of showers
and thunderstorm and now only am only forecasting a slight chance
for showers and thunderstorms in far southeast Georgia and that
should mainly be in the morning. Drier and more comfortable air will
move into the area with high temperatures mainly in the lower to mid
80s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Conditions should be mostly dry to start of the week while a stalled
front remains offshore and/or south of the region. However, guidance
suggests the boundary will drift back north and toward the coast
through the middle of next week. Given the setup, a slight chance of
showers/thunderstorms is forecast along coastal areas only on
Monday, but a gradual trend to chances of showers/thunderstorms is
anticipated Tuesday and Wednesday. Greatest precip coverage should
occur along coastal areas, especially in Southeast Georgia. Temps
will generally be a few degrees below normal next week, peaking in
the mid/upper 80s. Overnight lows will range in the upper 60s/lower
70s.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
KCHS through Friday morning: Still feel the chances for
noctural/late night showers and possibly thunderstorms will
increase after midnight. Latest mesoscale models keep the bulk
of activity just offshore. Thus, kept precip. mention out
through mid Friday morning. Did hint at the potential for lower
clouds MVFR/IFR late.
KSAV through Friday morning: Expect a similar pattern as
mentioned for KCHS with chances for showers and isolated
thunderstorms increasing later tonight. Again, have kept precip.
mention out of TAF through Friday morning, but showed potential
for IFR ceilings late as indicated by latest LAV guidance.
Extended Aviation Outlook: Periods of flight restrictions are
possible by later Friday morning and afternoon through Saturday
night in/around showers and thunderstorms. VFR conditions
should return Sunday and into the first part of next week.
&&
.MARINE...
Tonight: No highlights expected. Weak low pressure near the GA
coast will shift northeast with winds mainly from the S/SW 10 to 15
kt or less. Seas will build to 2-3 ft across the near shore
waters and to 3-4 ft across the offshore waters. Chances for
showers and thunderstorms are expected to increase overnight.
Some stronger storms could produce gusty winds and low visibilities
at times.
Friday through Tuesday: The waters should remain between high
pressure well offshore and a strengthening trough of low
pressure inland through Friday. A cold front will then approach
from the north/northwest Friday night and Saturday before moving
through the waters Saturday night. A chance for showers and
thunderstorms are forecast over most waters Friday and Friday
night, while showers and thunderstorms will be likely ahead of
and along the cold front Saturday and Saturday night. The front
could drift back over coastal waters by midweek, producing
additional showers and thunderstorms. Wind/sea conditions are
expected to remain below Small Craft Advisory levels through the
period. However, a southwest/south flow could gust around 20
kts Friday afternoon into early Saturday as the pressure
gradient tightens ahead of cold front. Seas will range between
2-4 ft, highest this weekend in advance of the cold front.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...RFM/RJB
SHORT TERM...MTE
LONG TERM...
AVIATION...MTE/RJB
MARINE...MTE/RJB
Area Forecast Discussion
National Weather Service Cleveland OH
937 PM EDT Thu Jul 27 2017
.SYNOPSIS...
A cold front will sag southward across the region this evening as
low pressure moves eastward across the lower Ohio Valley. The
low will move off the Middle Atlantic Coast on Saturday allowing
high pressure to build across the region Saturday night into
Sunday.
&&
.NEAR TERM /THROUGH FRIDAY/...
Just some minor changes to the forecast overnight. The precip is
just about gone and will leave a 20 pop in for another hour or
two otherwise will just go with a dry forecast overnight.
Northern areas are currently clear but still expect clouds to
increase overnight. No changes to temps as we should be able to
dry slightly in the northeast flow.
Previous...Low pressure over nrn Indiana this afternoon with a
weak cold front across far northwest OH. This low will drop SSE
across OH overnight as the front moves south. By morning the
from will be in southern OH with another developing surface wave
moving northeast toward the Lower Ohio Valley along the
boundary. The low will then move east to the Virginias by 00Z
Saturday. Forcing is weak with the system initially however
models continue to show an upper short wave moving through the
western lakes tonight and becoming a closed low Friday as it
reaches the area. Convective development has been quite limited
today with the focus remaining well south of the area in
vicinity of a warm front where instability is greater. Following
the HRRR will go with chance pops for a few
showers/thunderstorms mainly south/southwest mainly this
evening. For Friday will bring high chance and likely pops back
into the south and southeast portion of the area where moisture
is best as better forcing descends into the area with the upper
low. Friday night the system and associated moisture will pull
out as drier air and high pressure build in from the northwest.
Temps Friday a few degrees below normal with highs in the upper
70s.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
Showers should be SE of the forecast area by daybreak Saturday
as upper level trough slides SE. At the surface large Canadian
high will become the dominant weather feature through the
remainder of the weekend. Saturday will be cooler and drier with
highs only in the 70s. Little change for the remainder of the
forecast period with high pressure anchored over the Great
Lakes. Expect dry conditions with slightly below normal temps
and copious amounts of sunshine.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
In general surface high pressure will be in place to start. A cold
front will be dropping down from the upper Midwest for the second
half of the week, although there are differences in timing that wave
over the top of the western U.S. ridge. Will bring the mention of
showers/thunderstorms into the forecast for Thursday. Temperatures
will be seasonable each day.
&&
.AVIATION /00Z Friday THROUGH Tuesday/...
The front across the area continues to push. All of the precip
falling right now is south of U.S. 30 and this should all be
south of the area by sunset. The nighttime hours will be quiet.
Still expecting some MVFR fog to develop in the south late
tonight where rain has fallen. Fairly widespread MVFR cigs
should develop tomorrow morning in the northeast flow off of the
lake. It will take till sometime in the afternoon for cigs to
lift to VFR. By that time winds will have picked up. Gusts in
excess of 20 knots are expected during the afternoon.
OUTLOOK...Non-VFR in low ceilings Friday afternoon could
persist into Saturday.
&&
.MARINE...
The cold front across SE Lower Michigan will move across Lake Erie
tonight. Choppy conditions develop on the lake tonight as winds
turn to the NE and increase to 10 to 15 knots behind The front. A
Small Craft Advisory will be needed tomorrow as NE winds increase to
15 to 25 knots. Small Craft will likely continue into Sunday when
the winds begin to diminish as high builds in.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/Kubina
SHORT TERM...DJB
LONG TERM...Oudeman
AVIATION...Kubina
MARINE...DJB
Area Forecast Discussion
National Weather Service Dodge City KS
641 PM CDT Thu Jul 27 2017
...UPDATED AVIATION SECTION...
.SHORT TERM...(This evening through Friday)
Issued at 213 PM CDT Thu Jul 27 2017
Radar indicating some scattered afternoon convection continuing
across western Kansas this afternoon. These showers were occurring
ahead of a 400mb PV and along the 700mb deformation zone.
Following the RAP late today into early tonight these scattered
showers and isolated thunderstorms will slowly move southeast
towards Oklahoma early early tonight.
An upper level ridge axis will remain nearly stationary over the
central and northern Rockies overnight and Friday. NAM, GFS, and
ECMWF all showing another upper level wave rotating around this
upper ridge axis and out into the Central Plains on Friday,
however subtle differences on timing and track does exist. Even
with these subtle discrepancies it appears the better chances for
convection will be late Friday/Friday night but there is a slight
chance for a few storms near the Colorado border a little earlier
in the day.
Cloud cover and the forecast 900mb to 850mb temperatures at 18z
Friday and 00z Saturday continues to support another unseasonably
cool day. Highs in the 80s still appear reasonable with the cooler
temperatures in far southwest Kansas.
.LONG TERM...(Friday night through Thursday)
Issued at 213 PM CDT Thu Jul 27 2017
An extended wet period appears to be setting up for western
Kansas given the Northwesterly flow aloft and the location of
where the GFS and ECMWF develops a mid level baroclinic zone
across western Kansas from Saturday through early next week. At
this time the most favorable area for widespread precipitation
this weekend will be west of a Hays to Coldwater line. Heavy
rainfall can be expected with these storms this weekend and given
the potential that several rounds of storms will occur over the
same area day after day there will be a chance for some water
issues to develop, especially from Saturday night through Monday.
At this time will hold off issuing any type of flood watch
products but as confidence on location, amounts, and timing
improves this may be required.
Temperatures will stay unseasonably cool this weekend into early
next week based on the expected cloud cover and precipitation
chances. Highs mainly in the 80s still looks on track but if we
get a rain through most of the day the highs for that day could
easily end up being only in the upper 60s to lower 70s.
For the first half of the work week the better chances for
precipitation will begin to shift from far western Kansas to north
central and south central Kansas. Again the main hazards from
these storms early next week will be periods of heavy rainfall.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 634 PM CDT Thu Jul 27 2017
Light surface winds are expected through this TAF period as broad
upper high pressure dominates the region, with weak upslope
boundary layer winds. HRRR model does develop some post frontal
IFR category stratus late in the overnight which is reflected in
the southern terminals locations. Visibility is expected to remain
above the IFR category at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 87 67 87 / 20 10 20 30
GCK 67 86 66 85 / 10 20 30 30
EHA 66 84 65 87 / 30 30 50 30
LBL 69 84 68 87 / 30 40 40 30
HYS 66 88 66 86 / 10 10 10 20
P28 72 91 68 89 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Burgert
AVIATION...Russell
Area Forecast Discussion
National Weather Service Quad Cities IA IL
612 PM CDT Thu Jul 27 2017
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 318 PM CDT Thu Jul 27 2017
The main cold front extended from central MO to central Il and was
sagging southward. A secondary weak front or trough was moving
through northern IL (seen on visible satellite imagery) and was
producing a few showers on this boundary, but was east of the dvn
cwa. Despite the HRRR wanting to generate showers in the dvn cwa
there has been no evidence on radar as of yet. Will hang onto the
slight pops this afternoon just in case.
Northeast winds were coming off the Great Lakes with much drier
air across MN/WI/MI where dewpoints were in the 50s at many
locations. Across the dvn cwa, dews ranged from the mid 60s north
to the lower 70s south.
&&
.SHORT TERM...(This Evening through Friday)
ISSUED AT 318 PM CDT Thu Jul 27 2017
Forecast focus on delightful weather for the end of July.
Tonight: With loss of heating the cumulus clouds will dissipate
giving way to a clear and comfortable night, as dewpoints continue
to lower on northeast winds. Lows should range from 60 at
Freeport, Il to the mid 60s in extreme northeast MO.
Friday: High pressure building into the Great Lakes will bring a
fantastic day with comfortable humidity and light northeast winds.
Other than scattered fair weather cumulus clouds dotting the
landscape, there will be plenty of sunshine. Afternoon highs will
push into the upper 70s to lower 80s at most locations. ..Haase..
.LONG TERM...(Friday Night through Thursday)
ISSUED AT 318 PM CDT Thu Jul 27 2017
Friday night through the weekend...Latest run medium range models in
good agreement of suggesting long wave trof to continue to dig south
and establish acrs the Appalachians and Atlantic seaboard this
period, while broad upper ridge engulfs the west half of the CONUS.
Resultant amplifying northwest fetch will allow for a seasonably
robust llvl high pressure system to dump down out of Canada and
backdoor it`s way down the western GRT LKS this period. Looking at
extent of projected air mass influx, drier column from the sfc on
up, and thicknesses generally suggest lows at night well down in the
50s, with afternoon highs in the upper 70s to lower 80s. More areas
may have trouble making it out of the 70s on Saturday depending on
mix out depth, will have to go above H85 MB to get the 80s. H85 MB
ridge cool rule supports lows down in the low to mid 50s for much of
the CWA for both Fri and Sat nights.
Monday through next Thursday...Projected upper jet trends and extent
of the western ridge mass indicate the synoptic scale pattern to
adjust little and remain almost blocked until later in the week. The
air mass acrs the region will look to modify and warm back up to
normal levels this period. Looking at longer range trends, it
appears that ridge-riding wave energy will try to propagate
southeastward into the GRT LKS and re-enforce the troffiness from
the GRT LKS on eastward. In the process, it will try and shunt a sfc
front down acrs the local area from the north sometime Wed into Thu,
which may act as a focus for shower and thunderstorm development
during the afternoon and evening. But most of the medium range
solutions suggest marginal moisture feed and convergence into this
boundary and there may not be much organization to any convection...
sctrd diurnal clusters to isolated showers/storms both Wed afternoon
and possibly Thu. The 12z ECMWF really washes out this feature to
the south By next Thu and suggests most of the day to be dry. The
12z GFS of course is wetter and more bullish, festering rounds of
showers and storms from Wed into Thu acrs portions of the area.
Unless there can be a more enhanced low to mid level draw into the
front from the southwest to utilize some monsoonal influences,
currently see the 12z ECMWF solution becoming more viable for the
long range. ..12..
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
ISSUED AT 612 PM CDT Thu Jul 27 2017
VFR conditions will be the rule overnight through Friday as high
pressure builds into the western Great Lakes. There is a low
potential for patchy shallow ground fog, which is not mentioned in
the forecasts.
&&
.HYDROLOGY...
Issued at 318 PM CDT Thu Jul 27 2017
Only isolated showers and maybe a thunderstorm will be possible
this afternoon, thus no real additional impact expected to the
flood sensitive river basins. An extended period of dry weather is
still on track across the entire area from tonight through at
least next Tuesday night. This dry weather will allow area
waterways to go below flood stage and allow the saturated ground
across northeast Iowa and northwest Illinois to dry out. But
elevated readings on all area waterways are still expected into
early August.
Wapsipinicon River...
Moderate flooding is ongoing at Anamosa Shaw Road, but the gage that
was determined to be reading incorrectly has been adjusted to 18.8
feet. Still forecast there to start falling tonight and drop below
Moderate Flood Stage by late Friday morning. Major flooding still on
track near DeWitt by Saturday morning.
Rock River...
Major flooding continues along the Rock river. Joslin is falling
after a brief jump in the river level there from the storms over
that basin yesterday evening. Como will experience a secondary crest
around 13.2 feet by Friday afternoon. Moline continues to slowly
fall with the potential of dropping below Major Flood Stage there by
Sunday morning.
Pecatonica River...
Flooding continues along the Pecatonica River. The Winslow area is
observing significant flooding, with the crest near that location as
of Thursday morning. Downstream at Freeport the river should start
rising again as the crest makes its way downstream. However, the
timing of the rise and how much higher the river will go is still
uncertain as there is significant spreading of the water across the
rural areas. The current forecast is for the river to crest around
15.6 feet, but it could be up to 0.3 ft higher or lower than that.
Mississippi River...
Flood warnings remain in effect for minor flooding from Muscatine
down to Burlington, although Muscatine should drop below flood stage
this afternoon. The flood crest is at Gladstone L&D 18, and
currently approaching Burlington. Keithsburg appears to be slowly
falling and thus has crested earlier this morning.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...Haase
SHORT TERM...Haase
LONG TERM...12
AVIATION...Sheets
HYDROLOGY...Brooks/12
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1025 PM EDT Thu Jul 27 2017
.SYNOPSIS...
A strong cold front will cross the region from the west Friday
through Friday night. Cooler and drier air will arrive across the
western Carolinas and northeast Georgia through the weekend and
linger through the early part of next week. More typical summertime
conditions will return about the middle of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 1015 PM: Trimmed PoPs back a bit over the next few hrs, with
HRRR and NAMNest showing just some very isolated activity firing on
remnant outflows left behind by the current storms. I continue to
advertise an increase from north to south beginning after midnight
as the convergence zone and associated showers encroach from the
north. Temp trends were largely on track so far; the guidance blend
chosen by the previous shift accounted for the cirrus well. I did
make some minor adjustments to values later tonight as the newest
hourly guidance is overall a bit warmer. This is reflected in new
min temps.
The 18z NAM bucked the trend of late and showed less of a
stabilizing effect Friday due to the morning cirrus and possibly
light stratiform precip. 00z NAM continues this trend. Our
confidence has increased that at least the NC Piedmont, where
model consensus has been highest for significant instability,
will be at risk for severe wx. At least the GFS sweeps a cold
pool from upstream storms into our forecast area such that it
depicts virtually no sbCAPE across most zones by 18z. While
this is plausible, it`s by no means a given, and it does create
a considerable amount of uncertainty in tomorrow`s forecast. The
uptick in instability seen in the most recent NAMs is decreasing the
uncertainty for severe wx in our east, in that it lends confidence
to other solutions still showing high SBCAPE values there. However
it increases the uncertainty in how far west the advertised SPC
Slight Risk should be extended when Day 2 becomes Day 1 tonight.
At any rate, the potential for abundant buoyancy is a bit
disconcerting considering the anomalously strong mid/upper level
flow, with attendant deep layer forcing and low level & deep
layer shear of 25-35 kts, as one would typically expect a very
active severe weather day with such ingredients in late July. The
combination of upper support, along with lee side/pre-frontal
trough and perhaps outflow boundary(s) associated with the morning
convection should support scattered to numerous showers and storms
across the area by afternoon. The potential for a few significant
severe storms still cannot be ruled out. Tomorrow`s highs should
be a couple of degrees (if not more) below climo under expected
widespread mid/high clouds.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 225 PM EDT Thursday: The best upper-level forcing rounding the
slowly deepening eastern trough will likely cross our piedmont
Friday evening before swinging rapidly east to the coast overnight.
An attendant sharp cold front will also cross the region through the
nighttime hours. PoPs will thus remain fairly high during the
evening hours before drier air starts arriving from the northwest
overnight post-fropa. However, the best severe convective threat
should have passed east of the area by evening - unless any strong
redevelopment occurs along the immediate frontal zone. Showers may
linger along the northern mountains in moist low level upslope flow
well into Saturday morning.
A closed, upper-level low pressure system will then migrate from the
central Appalachians to the Virginia Tidewater region Saturday
through Saturday night. The surface cold front will depart southeast
of the region and drier air will work in. The main exception is that
a trailing vorticity lobe rounding the upper low will swing down
across the western Carolinas Saturday night, reinforcing moisture in
the 850 to 700 mb layer. This will lead to some return cloudiness,
but probably no associated showers.
Deep layer northerly flow will continue Sunday through Sunday night
on the back side of the deep eastern coastal trough. Periods of mid
level moisture could permit slightly higher cloud cover at times,
but with no attendant showers expected. Anticipate maximum
temperatures about 1 to 2 categories below climo by Sunday
afternoon.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 225 PM EDT Thursday: Reinforcing shortwave energy arriving
from the upper Midwest will keep a mean trough axis positioned over
the eastern U.S. Monday through Wednesday. Mainly dry surface high
pressure will sprawl over to the north of the region through this
same period. The airmass will slowly modify, with isolated
convective coverage returning to the southeast mountains late Monday
and then more typical diurnal mountain ridge top coverage Tuesday
through Thursday. Some modest height recovery is expected on
Thursday with max temperatures finally returning to near seasonal
normals.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: A few SHRA/TSRA will continue this evening
mainly over the mountains and Upstate. With abundant moisture and
increasingly perturbed upper level flow downstream of trough and
cold front, it is not out of the question that occasional showers
will redevelop overnight. Hence VCSH/VCTS is used liberally in
the first few hrs of the TAF and then returns in some places by
daybreak. Cirrus will continue to blanket the area and limit
radiation, so only the mountain valleys are expected to see
restrictions. Falling heights and the nearing cold front could
permit robust storms to develop Friday aftn...if we are able
to destabilize. Over the past few runs, guidance has mainly
indicated that remnant cloud cover and stratiform precip would
drift in from TN and keep us stable during the day. While this
still looks possible over the mountains and western Upstate,
over at least KCLT and KHKY trends suggest above-climatological
values of SBCAPE will develop. Stronger winds aloft imply a severe
wx risk with any storms that form in that environment, mainly in
the form of damaging winds. Hence PROB30s for those sites include
a gusty wind mention. Elsewhere the severe risk is smaller though
SCT storms may still form.
Outlook:Drier air will filter in from the north behind a passing
cold front this weekend. Chances for morning fog and stratus
will also be possible, Saturday morning, mainly in the mountain
valleys. A typical summer-time pattern is expected to return by
the middle of 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 83% Med 77% High 92% High 94%
KHKY High 100% Med 75% High 100% High 100%
KGMU High 100% High 98% 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 and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...HG
NEAR TERM...JDL/Wimberley
SHORT TERM...HG
LONG TERM...HG
AVIATION...Wimberley
Area Forecast Discussion
National Weather Service Wichita KS
654 PM CDT Thu Jul 27 2017
.SHORT TERM...(This evening through Sunday night)
Issued at 314 PM CDT Thu Jul 27 2017
Tonight, A diffuse frontal boundary is currently located from
Wellington to Iola or generally along and just east of the KS
turnpike. Latest satellite imagery shows some clearing just
southeast of the frontal boundary, with some CU trying to bubble
up due to the differential heating. Latest RAP data shows some
surface based instability continuing to pool just to the south of
the boundary with SBCAPE values of 2000-3000 j/kg.
Latest hi-rez model solutions suggest that the frontal boundary will
make slow progress to the south for the late afternoon hours. Some
concern that this front will linger over SE KS for the late
afternoon hours, with afternoon heating leading to renewed surface
based convection for late this afternoon, and early this evening
mainly across the Flint Hills, and areas southeast of the Wichita
metro area. So will keep some low pops across SE and southern KS for
this chance. Main concern with convection will be a few strong to
marginally severe storms with wind gusts to 50-60 mph and locally
heavy rainfall due to the slow movement and precipitable water
values of 200 percent of normal. As the evening progresses, think
the storm chances will shift to the south-southeast as the front
pushes into nrn OK.
Some concern that the elevated 850-700h baroclinic zone may linger
over srn KS which may lead to some additional showers/storms across
srn KS late this evening. But widespread subsidence looks to build
in behind the front, with the best FN-convergence located to the
south of the forecast area. So will continue to go with a pops
shifting south of the area.
By Friday morning, the front will be well south into Oklahoma
with some drier air finally making its way into the area. Upper
flow will become more northwesterly as a shortwave approaches the
Ohio Valley. This will also shove the upper ridge slightly
southwest along with the above normal temps. Any shower or storm
chances through the weekend will be tied to moonsonal
moisture/energy. High Plains of eastern CO/western KS will have
the higher chances through the weekend with a small chance some of
this may work into areas west of I-135 Sun evening. With rain
chances tied to such weak upper forcing, confidence is not very
high on how far east showers/storms make it.
Good news is that temps this weekend will be a few degrees below
normal as they top out in the upper 80s to around 90 degrees.
.LONG TERM...(Monday through Thursday)
Issued at 314 PM CDT Thu Jul 27 2017
Overall pattern will not change too much for next week with upper
troughing over the eastern CONUS with broad ridging over the
west/sw. This will keep close to or slightly below normal temps
in place through next week. Precip chances will continue to be
associated with desert sw moonsonal moisture that may try and push
east into the high Plains by mid week. The GFS in much more
agressive with this scenario compared to the ECMWF which does
decrease confidence with regards to precip.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 639 PM CDT Thu Jul 27 2017
850-700 mb frontal zone will be slow to shift southward out of
southeastern Kansas tonight. Clusters of showers/thunderstorms
will occur within this frontal zone, with most convection
remaining just south of the CNU terminal. Will include a VCTS at
CNU however. Northeasterly wind and low dewpoint depressions
should allow for MVFR/IFR stratus to develop overnight in south-
central and southeastern Kansas. The stratus in the south is
expected to lift/improve to VFR by midday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 71 90 67 88 / 10 10 0 0
Hutchinson 69 91 65 88 / 10 10 0 10
Newton 68 89 64 86 / 10 10 0 0
ElDorado 69 87 64 86 / 20 10 0 0
Winfield-KWLD 72 90 67 88 / 30 10 0 0
Russell 66 89 66 88 / 0 0 10 10
Great Bend 68 91 65 87 / 10 10 10 20
Salina 68 89 66 89 / 0 0 0 10
McPherson 68 90 64 87 / 10 0 0 10
Coffeyville 73 89 66 87 / 60 10 0 0
Chanute 71 86 65 86 / 20 10 0 0
Iola 70 85 64 85 / 20 0 0 0
Parsons-KPPF 72 87 66 87 / 40 10 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...RBL/Ketcham
LONG TERM...RBL
AVIATION...JMC
Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
920 PM CDT Thu Jul 27 2017
.UPDATE...
Have updated the forecast to removed the Heat Adv wording. Have
also made some tweaks to the overnight forecast....with isolated
to scattered SHRA/TSRA remaining possible overnight.
&&
.PREV DISCUSSION...(ISSUED 605 PM CDT Thu Jul 27 2017)
DISCUSSION...
Updated to include the 00Z aviation discussion below...
AVIATION...
Some isolated to scattered SHRA/TSRA will become more possible
this evening into the overnight hrs...though coverage will not be
too widespread at this time. As a result...just mentioning
VCSH/VCTS and TEMPOs for this activity. This precip could caused
decreased flight rules as well...especially under the strongest
storms. Winds will eventually shift to the N/NW near the end of
this TAF period.
PREV DISCUSSION...(ISSUED 200 PM CDT Thu Jul 27 2017)
Short Term...Tonight thru Saturday night...
This morning the short term models were backing off on precip
chances across the state this afternoon and tonight. However, the
last several runs have been ramping chances back up, and this is
consistent with observed radar and satellite trends.
During the last hour visible sat imagery has been showing a line of
convective clouds developing from NE AR into central AR, and radar
is now showing returns. This is now lining up well with the latest
HRRR runs indicating a line of convection forming from roughly JBR-
LIT at 21Z. With these trends I have upped POPs in the eastern and
southern portions of the forecast area tonight versus the earlier
forecast.
The cold front itself should come thru central AR around daybreak,
and will start to usher in the cooler and drier air we have been
mentioning for several days. Front should clear southern AR by
tomorrow evening and this will bring and end to POPs. Saturday
should be dry.
Models have been inconsistent with the extent of the cooling and
drying effect for several runs, but the latest trends are dropping
temps back to the mid 80`s north, the upper 80`s central, with
readings around 90 remaining across the west and the far south.
Certainly a nice cool down for late July, and this will be
especially apparent with the lower dewpoints, although the driest
air will not arrive until the extended term.
Extended Term...Saturday night through Thursday...
Northwest flow will be in place for the weekend, providing
continued relief from the heat and at least the possibility to
usher weather systems into the region late in the period. Max
temperatures will top out in the 80s through early next week and
gradually warm back into the 90s by mid week. As of now, models
are not picking up on any rain makers until late next week.
Introduced POPs on Thursday but would expect timing and chances to
be more fine tuned in the coming days.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
62
Area Forecast Discussion
National Weather Service Midland/Odessa TX
910 PM CDT Thu Jul 27 2017
.DISCUSSION...
Area radars show convection has pretty much died out, except for a
few lingering cells on the Diablo Plateau. 00Z NAM zeroes out
convection for the rest of the night, but the HRRR is persistent
in spotty convection near current activity. We`ll take POPs down
to bare minimums to cover this, and update other parameters as
necessary. Updates out shortly.
&&
.PREV DISCUSSION... /issued 606 PM CDT Thu Jul 27 2017/
DISCUSSION...
See 00z aviation discussion below.
AVIATION...
VFR conditions are expected for the next 24 hours. Winds will
mostly be out of the southeast and will weaken late this evening.
There is a slight chance of thunderstorms but chances are too low
to mention at this time.
PREV DISCUSSION... /issued 437 PM CDT Thu Jul 27 2017/
DISCUSSION...
We`ll do a quick update to include convective activity near
Alpine. Updates out shortly.
PREV DISCUSSION... /issued 144 PM CDT Thu Jul 27 2017/
DISCUSSION...
Central and Western U.S. locked into a summer pattern with ridge in
control of wx. The upper ridge centered over NM this morning will
wobble around but not shift west until early next week. As it does
temperatures should decrease a little and rain chances increase.
Persistent S/SE wind will keep low level moisture high which will
help to moderate temperatures. Current dewpts into the lower 60s.
The normal high for most of the region for late July is the mid 90s.
Expect highs a little above normal in the uppers 90s through the
rest of the week with 100 or more along the Pecos and Rio Grande.
With so little day to day change went with a blend between guidance
and persistence. The last time MAF recorded 100 degrees or more was
July 3rd. Next week may be a a little cooler with long range
guidance trending downward as the ridge center moves off.
Had a few showers and storms kick off before noon in Eddy county but
as of 18z most precip is west of the CWA. Model qpf keeps the
precip mainly around the western edge of the region due to the
ridge. Best chances the rest of the afternoon and evening should be
over the higher elevations from near CNM to MRF. QPF also shows a
little precip moving down across the NE Permian Basin Saturday night
and/or Sunday as shortwaves come down around east side of ridge.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 75 99 73 100 / 0 0 0 10
Carlsbad 73 100 72 99 / 10 10 10 10
Dryden 75 99 75 102 / 0 0 0 0
Fort Stockton 73 98 73 99 / 0 0 0 0
Guadalupe Pass 69 89 68 90 / 10 10 10 10
Hobbs 70 96 70 96 / 0 0 0 0
Marfa 64 90 60 91 / 10 10 10 10
Midland Intl Airport 74 99 74 99 / 0 0 0 0
Odessa 74 99 74 99 / 0 0 0 0
Wink 74 102 73 102 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
80/44
Area Forecast Discussion
National Weather Service Paducah KY
717 PM CDT Thu Jul 27 2017
.UPDATE...
Issued at 716 PM CDT Thu Jul 27 2017
There remains minor shear, moderate surface based CAPE, little
CIN, weak surface convergence (between the approaching cold front
to the north and departing MCV/effective outflow boundaries over
the southern Kentucky Pennyrile region of west Kentucky) across
the WFO PAH forecast area.
Given the weak shear aloft, the cirrus canopy from the morning and
afternoon convection limited effective heating of surface parcels
to support widespread convection. Where there was differential
heating, updrafts remained weak, making most storms outflow
dominated. In the absence of persistent upshear flow (except with
the interaction of the MCV with outflow boundaries), any potential
for multi-cell thunderstorm development was mitigated.
Cannot rule out some focused convection with the cold frontal
boundary, but had to consider a significant reduction in the
overall PoP/Weather picture for tonight, especially between the
front and the departing MCV this evening. Adjusted the
differential mention of thunderstorms to be tied with the
departing MCV in the southern Pennyrile of west Kentucky and over
with the cold front, mainly over southwest Indiana, southeast
Illinois, and northwest Kentucky.
The high resolution, convection allowing, HRRR model family, as
well as the NAM-WRF family suite was used to reflect rain chances,
rainfall amounts, weather type, and cloud cover for tonight. There
is some concern that the difluent northwest flow aloft may
tighten up Friday morning, keeping a small chance for convection
over the southern part of the WFO PAH forecast area in place early
Friday, but will need to see how the shortwave/low over Lake
Michigan will react later tonight to determine whether it will be
worth dropping any additional rainfall mention on Friday.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 249 PM CDT Thu Jul 27 2017
A cold front over central Missouri and central Illinois this
afternoon is heading southeast. This front will bring much quieter
and drier weather by the weekend. In the meantime, there will be
some potentially strong convection to deal with.
As of mid-afternoon, scattered storms were developing across the
Lower Ohio Valley. These storms were developing on the northern
edge of a pool of very moist and unstable air that was unaffected
by the early morning mcs that tracked across Illinois. These
storms were supported by a mesoscale vorticity center over south
central Missouri, which was evident in radar loops. This vort
center was generated by an early morning mcs over western
Missouri.
In the near term, convection will likely expand in coverage across
the very unstable air over western Kentucky and extreme se
Missouri late this afternoon. Once the atmosphere is raked over
and the vort center passes to our southeast this evening, there
should be relatively little activity on radar. A second smaller
round of storms is likely late tonight along the actual cold front
as it moves southeast across the Ohio River and southeast
Missouri.
Heavy rain appears to be the primary hazard given high precip
water values over two inches. There is also some potential for
training cells if an organized mcs develops. Corfidi vectors
indicate a slow southward motion to any organized mcs that forms.
Individual cell motion is mostly to the east.
Once the front exits the Pennyrile region of western Kentucky
Friday morning, there will be a slow drying trend during the
afternoon. Some isolated weak convection could lag behind the
front as a strong 500 mb shortwave drops south-southeast across
the Great Lakes region. The drier air will be slow to filter south
initially, which means dew points will still be mostly in the 70s.
However, clouds should keep high temps mostly in the mid 80s.
Saturday and Saturday night will be noticeably cooler and drier.
Little if any cloudiness is expected. Model soundings indicate any
diurnal cumulus clouds would be scattered at most. Even with full
sun on Saturday, highs will range from 80 to 84 with a north
breeze. Overnight lows will be in the upper 50s and lower 60s
Saturday night, which will be the coolest night since June 28.
.LONG TERM...(Sunday through Thursday)
Issued at 249 PM CDT Thu Jul 27 2017
The overall forecast confidence is high.
The dominant feature on the weather map throughout the extended
forecast will be a strong upper-level ridge over the western half of
the country. This will result in troughing of some amplitude over
the eastern half, including our region. At the surface, cool, dry
high pressure will remain in place through much of the period. The
airmass will slowly moderate, but south winds never really get
established, so the moderating process will be slow.
The medium range models bring an upper-level storm system southeast
through the Great Lakes or Northeast on Thursday, which could push a
cold front into our region. Depending on the strength/path of this
system, some convection may reach our eastern counties Thursday
afternoon.
&&
.AVIATION...
Issued at 716 PM CDT Thu Jul 27 2017
Removed measurable rainfall chances for the WFO PAH TAF sites for
the 00z Friday issuance. The trend is still to move from a chaotic
VFR cloud deck/ceiling (due to scattered convection) toward a
MVFR/IFR ceiling and visibility combination as the frontal
boundary works through each of the WFO PAH TAF sites overnight. A
return to VFR category forecast should dominate the region after
14z Friday for all of the WFO PAH TAF sites.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...Smith
SHORT TERM...MY
LONG TERM...DRS
AVIATION...Smith
Area Forecast Discussion
National Weather Service Pueblo CO
311 PM MDT Thu Jul 27 2017
.SHORT TERM...(This evening through Friday)
Issued at 309 PM MDT Thu Jul 27 2017
Current water vapor imagery indicating upper high across the
Southern High Plains and the Southern Rockies, with weak west to
southwest flow aloft across the state at this time. Monsoonal
moisture plume remains entrenched across the region, however,
satellite blended total precip waters indicating best moisture
across the southeast plains (PWATS 170 percent of normal) sliding
south into eastern New Mexico, as some slightly drier air (PWATS 100-
125 percent of normal) is working into western Colorado at this
time. Regional radars indicating scattered to numerous showers and
storms over the higher terrain, with the best coverage over the
southern mountains at this time. Further east, mcv from last nights
convection still helping to keep a few storms across the far
southeast plains, with a more stable airmass in place across the
rest of the plains at this time.
Tonight...Latest high res models continue to support storms across
the higher terrain through the evening, with most of the convection
diminishing with the setting of the sun, save for a few possible
storms across the southern mountains into early Friday morning.
Storms try and move east across the I-25 corridor, though look to
diminish as they encounter the more stable air, though latest HRRR
does indicate a few storms possibly moving across the southern I-25
corridor through the late afternoon and early evening. With the
ample moisture in the air, there could be some patchy stratus/fog
develop across the eastern plains overnight, though currently
thinking there will be enough high clouds moving across the area
overnight and did not include in the forecast at this time.
Friday...Not much change in the current forecast, with quasi-
stationary upper high keeping weak west to southwest flow aloft
across the region. Best monsoonal moisture remains just south of the
area, though still enough moisture to support another round of
scattered to numerous afternoon and evening storms over and near the
higher terrain. Storms will be slow moving, with locally heavy
rainfall and the potential for flashing flooding over area burn
scars the main threat from storms. With slightly warmer conditions
expected, through will see a slightly better chance of storms across
the eastern plains in the afternoon.
.LONG TERM...(Friday night through Thursday)
Issued at 309 PM MDT Thu Jul 27 2017
.Saturday through Monday...Plenty of moisture will remain over
the region. Surface high pressure centered over the midwest will
tend to keep upslope flow over the eastern plains and into the
eastern mountains. Models show dew points generally in the 50s
continuing into next week. In addition, the upper level ridge will
remain centered over or near New Mexico, keeping the monsoon
plume over the region. With all the available moisture, threat for
convection, with heavy rain possible, will continue into next
week. Subtle features, which are tough to forecast more than a day
in advance, will determine the favored locations for convection
and the threat for heavy rains. Could not improve on CR model
blends so only made very minor adjustments. Convection will be
likely over the mountains most afternoons and evenings, with high
scattered PoPs elsewhere. Temperatures will remain near or below
average with usplope flow on the plains and afternoon convection.
.Tuesday through Thursday...Upper ridge builds westward over the
Great Basin with northerly flow aloft developing. This will bring
in drier air aloft, which will tend to decrease chances for
convection. However, disturbances moving southward on the east
side of the ridge could enhance convection, especially over the
plains and eastern mountains. GFS is more bullish on convection
than the EC. Grids have decrease in PoPs starting Tuesday, but
they are not as dry as the EC would suggest. --PGW--
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 309 PM MDT Thu Jul 27 2017
Generally VFR conditions expected at COS and PUB over the next 24
hours, as the atmosphere remains stable from yesterday`s rain. Still
could see a few storms try and move east across the Pikes Peak
region, though would expect storms to diminish as they move into the
more stable atmosphere. With ample moisture across the region, could
see some patchy stratus develop across the eastern plains, however,
currently thinking there will be too much high cloudiness to
indicate the mention in the TAFs attm. Will see a slightly better
chance of storms moving across COS later tomorrow afternoon.
ALS will continue to see chances of storms through the early
evening, with brief MVFR/IFR conditions possible in locally heavy
rain. High clouds to prevail through the overnight, with another
chance of storms tomorrow afternoon.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MW
LONG TERM...PGW
AVIATION...MW
Area Forecast Discussion
National Weather Service Charleston WV
1046 PM EDT Thu Jul 27 2017
.SYNOPSIS...
Low pressure system brings rounds of showers and thunderstorms,
with heavy rain, through Friday. High pressure with cooler and
less humid air follows for the weekend into next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1045 PM Thursday...
Lowered PoPs a little overnight. Rainfall is mainly light to
moderate, with rates expected to pick up early Friday morning
in the middle Ohio Valley, and by midday Friday or so over West
Virginia.
As of 825 PM Thursday...
Forecast on track with minor adjustments. Bands of showers
continue to back build, with other shower clusters forming well
upstream, to keep high PoPs going into the overnight. Adjusted
chance for thunder downward based on blended CAPE.
As of 215 PM Thursday...
The HRRR and the RAP have been consistently depicted a relative
lull in the convection for about a 4 hour window or so, with the
timing depending on location, before the next wave of
convection moves through. After a morning of priming with
scattered storms, a flash flood warning is now in effect until
the front exits the region tomorrow evening.
PWAT values are in the 1.5 to 2.0 inch range again, hence the
heavy rain that has already been seen, with many cells giving
one half inch in 30 minutes being the norm. Instability is high
in the mixed and most unstable layers.
Convective debris is dissipating off to the west, so expect the
convection to fire again upstream, as mentioned earlier in
regards to the flash flood watch. Severe threat is marginal, and
most storms have not eclipsed the 35mph wind mark, nor have they
produced any hail.
High dewpoints keep the overnight lows near 70F for the
lowlands.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
As of 315 PM Thursday...
Models continue to target our area for heavy rain Friday. Waves
of low pressure will be moving up along a slow moving cold
front that will cross our area from west to east during the day
Friday. With very moist (PW`s above 2 inches) and unstable air
in place with the front, there is a Flash Flood watch through
the day Friday. The front will finally be kicked east of the
area Friday evening as an upper low drops south across the Great
Lakes and into our area. Showers will end from west to east
west of the Ohio River Saturday night, but showers will continue
through the day Saturday over much of West Virginia as the
upper low stalls over the Mid Atlantic states. The upper low
finally shifts far enough east for all rain to end saturday
night. It will be warm and humid ahead of the front, and much
cooler behind the front with temperatures going well below
normal.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 335 PM Thursday...
A cool and dry period is on tap as Canadian high pressure will
be in control from Sunday into much of the next work week.
There will be a slow increase in high temperatures each day, but
it will be dry with temperatures at or below normal.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
As of 825 PM Thursday...
A low pressure system crossing the area this period will keep
showers ongoing. The best chance for thunderstorms is Friday
midday and afternoon, although lightning can be seen at almost
anytime.
VFR to at times MVFR conditions tonight, and an IFR ceiling here
and there, will trend toward an MVFR / IFR mix overnight into
Friday, and not much if any improvement is expected Friday
afternoon. Also, an overnight lull in rain would lead to lower
ceilings in stratus, and lower visibilities in fog, primarily in a
04Z to 14Z time frame.
It is important to note, however, that in thunderstorm
environments, the atmosphere changes significantly from the
model initializations, and in many cases, renders the second
half of the forecast less accurate. Thus, there will likely be
significant timing issues with the TSRA/VCTS in the forecast
beyond the 6 hour time frame.
Light south to southwest surface flow overnight will become
north, behind a low pressure system crossing the middle Ohio
Valley, Friday. Light west to southwest flow aloft will likewise
become light to moderate north, as the low presses the middle
Ohio Valley on Friday.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: Medium to high on the occurrence of
convective activity, low on timing.
ALTERNATE SCENARIOS: Timing of showers and thunderstorms, and
associated flight categories, could vary, with short term
amendments likely needed.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 07/28/17
UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
EDT 1HRLY 23 00 01 02 03 04 05 06 07 08 09 10
CRW CONSISTENCY H H M M M M L M M L M L
HTS CONSISTENCY M M M H M H M H H H M L
BKW CONSISTENCY L H M H H H M M M M H L
EKN CONSISTENCY L L L M M M M M M M M L
PKB CONSISTENCY L L M L L L L L L M M L
CKB CONSISTENCY L H H H M M M M M L M L
AFTER 00Z SATURDAY...
IFR in showers, stratus and fog possible Friday night into
Saturday.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flash Flood Watch through Friday evening for WVZ005>011-
013>020-024>034-039-040-515>526.
OH...Flash Flood Watch through Friday evening for OHZ066-067-075-
076-083>087.
KY...Flash Flood Watch through Friday evening for KYZ101>103-105.
VA...Flash Flood Watch through Friday evening for VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...TRM/26
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...TRM
Area Forecast Discussion
National Weather Service Shreveport LA
1003 PM CDT Thu Jul 27 2017
.DISCUSSION...
A quiet evening will manage much of the night with debris cirrus
aloft. Our temperatures are still ranging in the 80s with only a
couple of upper 70s. Thats where most of us will end up by
daybreak with a couple mid 70s maybe. No changes to going
forecast as HRRR does show spotty QPF by 12Z in our North, we will
keep the slight chance wording in place and await the front
tomorrow night and hopefully a good wetting rain areawide. /24/
&&
.PREV DISCUSSION... /issued 727 PM CDT Thu Jul 27 2017/
UPDATE...
To rerun zones without the heat advisory headlines.
DISCUSSION...
With the exception of De Queen`s 106 all current heat indices are
below 105. Storms are brewing in AR well ahead of the cold front
and will make for a quiet evening for us arriving after midnight
if at all. This approaching cold front will increase our chance
for rain for the next day or two and will slowly filter down,
bringing clouds as much as rain. Hopefully for all of our area,
but we will check new numbers with 00Z data before any further
issuance on the heat. /24/
PREV DISCUSSION... /issued 703 PM CDT Thu Jul 27 2017/
AVIATION...
VFR conditions should continue through the 28/00Z TAF period. An
extensive cirrus shield will linger across much of the region
overnight, as sct convection continues to develop this evening
along an old outflow bndry over Cntrl and Ern AR and spill WSW
around the upper level ridge centered over OK/Wrn AR. Can`t rule
out brief IFR/low MVFR cigs around/shortly after 12Z Friday over
portions of Deep E TX (possibly affecting LFK)/Wcntrl LA, but a
sct cu field should develop around midday areawide. Convection to
our N tonight may build SSE across Cntrl AR overnight, and could
send a bndry S to trigger additional sct convection around/after
12Z over SE OK/SW AR, possibly affecting the TXK/ELD terminals.
Have inserted VCSH mention for TXK at 12Z for the potential for
elevated -SHRA, but more sfc based convection may affect ELD after
12Z, lingering over SW AR through much of the morning before
diminishing. Bndrys from this convection may shift S into portions
of NE TX/N LA through the afternoon, which may trigger additional
sct convection over E TX/N LA, but low confidence when and where
precludes mention attm. Sct convection looks to continue/shift SSE
across the remainder of E TX/Ncntrl LA Friday night. S winds
3-7kts tonight will become WSW around 10kts after 15Z. /15/
PREV DISCUSSION... /issued 407 PM CDT Thu Jul 27 2017/
DISCUSSION...
The upper level ridge axis continues to hold strong across the
southern CONUS with mostly middle 90s for highs this afternoon.
As was the case yesterday, most locations reached heat advisory
criteria while a few areas mainly in northeast Texas managed to
mix out dew points into upper 60s which keep them slightly under
105 degrees for max heat indices. Fortunately, this spell of hot
weather is nearing the end of its run as a rare mid-summer cool
front is making its way south across the Plains with its aim on
the Gulf Coast as we head into Friday and through the weekend.
Unfortunately, we`ve got one more hot day ahead on Friday before
the cooler and drier air really begins to arrive. However, cloud
cover ahead of the frontal boundary should help to keep daytime
temperatures a few degrees below what we saw today so have opted
not to extend the heat advisory beyond its 7 PM expiration this
evening and will defer to the evening/overnight shifts on a final
call as to whether an advisory is needed for any of our southern
sections on Friday.
Confidence is still not great on widespread convection with this
front so have held pops down to just chance category for now. If
the front slows its progress like models have suggested it may, we
may have a more prolonged period with showers and storms along the
front such that more areas may see rainfall. Although a few storms
may sneak into our extreme northern zones late tonight, the best
chances for rain will come late Friday over our northern sections
through the day Saturday farther south along the I-20 corridor and
points south. Rain will gradually taper off from north to south on
Saturday as the front eases on south toward the coast with cooler
and drier air mass filtering in behind it. Pleasant temperatures
will come for the latter half of the weekend into early next week
with a gradual moderation back near seasonal averages by mid week.
/19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 78 94 79 91 / 0 20 40 30
MLU 77 91 76 89 / 0 30 50 50
DEQ 75 93 74 91 / 20 40 30 10
TXK 78 94 76 90 / 10 30 40 20
ELD 76 92 74 89 / 10 40 50 20
TYR 78 96 78 93 / 0 10 30 30
GGG 78 95 77 92 / 0 10 30 30
LFK 76 97 77 94 / 0 10 30 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
24/15