Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/23/21
Area Forecast Discussion
National Weather Service Denver/Boulder CO
923 PM MDT Thu Jul 22 2021
.UPDATE...
Issued at 915 PM MDT Thu Jul 22 2021
Convective coverage continue to wane this evening. The showers left
are producing light rainfall. There is little to no lightning
anywhere over the CWA. All the flood advisories have ended. Models
indicate the convection should be done by 06Z-07Z. The water vapor
pictures show that fairly decent moisture is now in place under
the upper ridge. Will make a few GFE grid adjustments to the
pops, sky cover, and QPF on this update.
&&
.SHORT TERM...(This evening through Friday)
Issued at 223 PM MDT Thu Jul 22 2021
Weak flow aloft tonight will be over the region with the upper
ridge centered around the Four Corners, and a closed upper low
over west TX. Some minor flooding issues in the Cameron Peak burn
areas this afternoon. The latest HRRR runs continue to generate
thunderstorms over the mountains and foothills this afternoon,
then shift some of those storms eastward into the urban corridor
by early this evening. Precipitable water values not as high as
yesterday, but still enough to produce moderate to heavy rainfall
coupled with the slower storm motions. Threat will increase over
all the burn areas on Friday, as models continue to show an uptick
in the precipitable water values Friday afternoon, with
subtropical moisture increasing over the forecast. On Friday, the
upper low will shift slightly northwestward as will the center of
the ridge as it moves over central UT. This will result in a
continued weak north/northeast flow regime in the mid levels.
Another warm afternoon on tap with high temperatures in the mid
90s once again. Storm motions weak on Friday, with 700/500 mb
layer winds less than 10 kts. Mixing ratios in this same layer
around 6 g/kg this aftn increase to 8 g/kg over the high elevation
areas Friday aftn. Heavy rain will be a threat everywhere by late
in the day, but the biggest threat will be over the burn area
which is where the flash flood watch in effect.
.LONG TERM...(Friday night through Thursday)
Issued at 223 PM MDT Thu Jul 22 2021
An elongated upper level ridge of high pressure will stretch from
Central California into the Southern Plains States Friday night
through Sunday with an easterly wave moving west across the Desert
Southwest. Abundant monsoonal moisture will still remain in place
over Colorado with PW`s ranging between 0.75" to 1.00" in the high
country and 1.00" to 1.50" on the plains through Saturday.
Values are expected to decrease somewhat on Sunday, but will still
be anomalously high. In addition, a weak cool front moving across
Northeastern Colorado will bring slightly cooler temperatures and
weak upslope flow east of the mountains on Saturday. Therefore, it
looks like there is a good chance that the 90 day streak will end.
This pattern should produce isolated to scattered showers and
storms across the plains with scattered to numerous showers and
storms over the high country. The storms will be slow moving and
capable of producing locally heavy rain and flash flooding,
especially across the burn areas. At this time it looks like the
greatest risk for flash flooding will be Friday night and Saturday
with a lower risk on Sunday.
Drier weather is expected Monday through Thursday as the upper ridge
builds over the Rocky Mountain Region and Central Plains States. The
plains should be mostly dry through this period with above normal
temperatures. Max temperatures will be in the 90s each day with
possibly reaching a 100 degrees in some locations Tuesday and
Wednesday. The mountains will continue to see scattered afternoon
showers and storms each day through the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 920 PM MDT Thu Jul 22 2021
Drainage winds have already kicked at DIA. Precipitation looks to
be over for the night. There should not be any drainage issues
overnight.
&&
.HYDROLOGY...
Issued at 223 PM MDT Thu Jul 22 2021
There will be an elevated risk of flash flooding for burn areas on
Friday, with a low risk of flooding elsewhere. Increased moisture
and slow moving storms will create a higher risk of heavy rain.
Abundant moisture and slow moving storms will create the potential
for heavy rain and flash flooding Friday night through Sunday. The
greatest risk for flash flooding will be Friday evening and then
again on Saturday, especially over the burn areas. The risk will
be somewhat lower on Sunday due to a decrease in monsoonal
moisture. For Monday through Thursday, warmer temperatures are
expected with a lesser chance of showers and storms. However,
there may still be a low risk for flash flooding across the burn
areas any of these days.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from Friday afternoon through Friday evening
for COZ033>035.
&&
$$
UPDATE.......RJK
SHORT TERM...Cooper
LONG TERM....Kalina
AVIATION.....RJK
HYDROLOGY....Cooper/Kalina
Area Forecast Discussion
National Weather Service Des Moines IA
857 PM CDT Thu Jul 22 2021
.UPDATE...
Issued at 843 PM CDT Thu Jul 22 2021
Overall...quiet evening across the state of Iowa. Expecting mostly
clear conditions overnight with low temps in the upper 60s to
lower 70s. Could see a few high clouds spill in from the Dakota`s
convection late tonight.
Of interest continues to be the smoke from ongoing wildfires
across the west. The GOES-16 GeoColor imagery around sunset
showed impressive smoke coverage across much of central US -
pretty amazing. For tomorrow, the vertically integrated smoke
parameter from HRRR-Smoke indicates relatively higher
concentrations of smoke drifting south/southeastward across the
forecast area. Not seeing any restrictions to sfc vsby across
SD/MN so feel most of the smoke remains well off the sfc. Skies
will defintely look hazy once again but dont feel this should
impact high temps much /maybe a degree or so/ with highs still
forecast to reach the lower 90s in most locales.
&&
.DISCUSSION.../Tonight through Thursday/
Issued at 228 PM CDT Thu Jul 22 2021
Key Points:
-Heat and humidity settle across the area
-Mainly dry with a few small windows for precipitation
Details:
A few light rain showers across northwest Iowa early this
morning moved across north-central Iowa through the early afternoon,
feeding off weak lift on the nose of the thermal ridge as it shifts
east. Increased moisture transport across the area has allowed
dewpoints this afternoon to reach the upper 60s and 70s with
diurnally driven cumulus evident in GOES-East imagery.
By Friday the thermal ridge axis will pass across the area, pushing
temperatures here into the low 90s. The temperature forecast
Friday is not straightforward, however, as the thermal ridge will
battle increased smoke across the region. HRRR vertically
integrate smoke simulations continue to indicate a slug of higher
concentration smoke moving across the area on Friday, as noted in
previous discussions. How this increased haziness influences
temperatures remains unclear. Either way, Friday will be quite
warm - the first day of many in a prolonged stretch of 90+ degree
days.
On Saturday warm air advection and moisture transport crank up across
the area, allowing temperatures to soaring to the mid to upper 90s
with heat indicies of 100-105+ possible across southern Iowa.
Meanwhile, a ridge rider shortwave will move across northern Iowa
which could bring chances for precipitation to northern counties,
however most activity will remain north of the area in southern
Minnesota. By Sunday into to Monday the ridge axis is squashed down
a bit by shortwaves traversing the ridge, helping to pull
temperatures back a few degrees. Instability Monday will be more
than sufficient within this hot/humid airmass and with 0-6km shear
approaching 30 kts, storms could be organized enough for some
severe potential. Otherwise, high pressure settle across the area
with both the GFS and Euro suites indicating temperatures soaring
by the middle to end of next week. All indications point towards a
very warm end to July.
&&
.AVIATION.../For the 00Z TAFS through 00Z Friday evening/
Issued at 620 PM CDT Thu Jul 22 2021
VFR conditions expected this period. Tonight, diurnal cumulus
clouds should dissipate around sunset with just some high clouds
overnight. With winds staying up around 10kts, not expecting any
HZ or FG formation. Similar conditions on Friday with a few
cumulus clouds and prevailing south/southwest winds from 10-15kts
in the afternoon.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Fowle
DISCUSSION...Hagenhoff
AVIATION...Fowle
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
258 PM PDT Thu Jul 22 2021
.SYNOPSIS...Temperatures will warm into the 90s to low 100s this
weekend. In addition, periods of sunshine and mild afternoon
conditions are expected along the coast. Otherwise, showers and
thunderstorms will be possible next week as monsoon moisture
spreads north across the region.
&&
.DISCUSSION...An upper trough positioned over the NERN PAC and
PACNW is forecast to exit the region, and will be followed by a
transition to quasi-zonal flow aloft Friday through the weekend. A
warming trend will subsequently occur over NWRN CA, with interior
valley highs expected to range from the 90s to low 100s. In
addition, nocturnal marine stratus development is forecast to be
highly localized near Humboldt Bay and the Fort Bragg area during
the next 24 hours. Hi-res model cross sections indicate those
areas of stratus will quickly dissipate by midday, with abundant
sunshine yielding mild afternoon conditions. However, HREF and
deterministic 12 km NAM guidance shows stratus spreading from
offshore areas toward the coast Saturday morning...which may
jeopardize another day of pleasant afternoon coastal conditions.
Otherwise, model guidance continues to show an anomalous plume of
monsoon moisture spreading west and north around an anticyclone
located over the Intermountain West. That moisture is forecast to
move across NWRN CA Sunday night into Monday, and then linger
through mid week. In addition, a fairly potent PV anomaly is
forecast to move north across the region on Wednesday. Ascent
occurring downstream from that feature combined with a moist and
weak to moderately unstable airmass will likely yield shower and
thunderstorm development. However, the official forecast remains
dry due to uncertainty in the magnitude and timing of thunderstorm
ingredients.
Garner
&&
.AVIATION...This morning`s stratus coverage was nearly a carbon
copy of Wednesday`s. There was a bit more stratus offshore, and
coastal clearing was a bit later than yesterday. The marine layer
is shallower than yesterday at this time, and the low-level
inversion has strengthened. Expect stratus to re-develop along the
North Coast tonight. However, there will be less inland coverage
due to the shallower marine layer. The thickest clouds should be
from Cape Mendocino to the Humboldt Bay area, but some near shore
eddies may advect low clouds and fog northward toward Crescent
City (per HRRR model guidance). Conditions at KUKI are expected to
remain VFR. Winds will be generally light, with afternoon and
evening gusts at KCEC. /SEC
&&
.MARINE...Northerly winds are expected to continue through the
period, with occasional gusts to gale force across portions of the
outer waters. The latest forecast package doesn`t support Gale
Warnings or Hazardous Seas Warnings, so will stick with a strongly
worded Small Craft Advisory. The best chance of gale force gusts
will be downwind from coastal promontories, but areal coverage
within each zone will be much less than 50%. A mid-period NW swell
and a long period SSW swell will return late in the weekend, but
both of these swell trains are expected to be fairly small, and
the forecast will be dominated by short period, locally generated
waves. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...None.
NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until
3 AM PDT Saturday for PZZ450-455.
Small Craft Advisory until noon PDT Sunday for PZZ470-475.
&&
$$
Visit us at https://www.weather.gov/eureka
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https://www.facebook.com/NWSEureka
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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
546 PM MDT Thu Jul 22 2021
...UPDATED FOR THE 00Z TAF CYCLE...
.AVIATION...00Z TAF CYCLE...
Mostly VFR conditions expected over the next 24 hours. The
exceptions will be near SHRA/TSRA, where MVFR to IFR is possible.
The best chances for storms remain over the western portions of
the CWA, especially west of KTCS and KDMN. Thus, kept the VCTS
for another hour or so, as there are storms to the west.
Overnight, there are chances for storms, but the latest model
runs keep TSRA away from any TAF site. Tomorrow after 18Z storms
return to the forecast, beginning in the mountains and
subsequently moving to the lowlands. But kept the mention of
storms out of the TAFS due to low confidence of actually hitting
any sites yet. Winds will be generally from the south AOB 12 kts early
on, then become from the southwest after 18Z. The exception will
be near TSRA where gusty and erratic winds are possible.
&&
29
.PREV DISCUSSION...242 PM MDT Thu Jul 22 2021...
.SYNOPSIS...
An approaching disturbance will end our quiet period beginning
this evening, as thunderstorms form over the Gila Region and the
area near the Arizona border. Moisture will increase significantly
Friday as the disturbance passes over our area, resulting in
thunderstorms area wide. Heavy rain is possible, especially west
of the Rio Grande. This will continue into Saturday before backing
off somewhat Sunday. Temperatures will be a little below normal
until next week, which will be a little hotter with fewer storms.
&&
01
.DISCUSSION...
.SHORT TERM...Tonight and Friday...
Moisture is slowly recovering this afternoon as an upper-level high
and upper-level low work to pull in some better mid and upper level
moisture. Dewpoints are still on the meager side with most locations
in the U40s and L50s though areas along the AZ border are much
higher. Moisture is expected to continue to increase. What that
means for the afternoon is thunderstorm chances will mainly be over
mountain areas and near the AZ border. Most lowland locations will
stay dry thanks to the lack of moisture. There is a fly in the
ointment for rain chances, as the upper-level low near the Big Bend
continues to approach, UL support will increase and thunderstorm/
shower chances will increase in spite of the lack of moisture. The
NAM Nest and HRRR give two very different solutions for the
overnight periods as to whether the lowlands will see showers/storms
tonight. The difference will affect tomorrow`s forecast. Fewer
storms tonight will lead to increased storms tomorrow and vice
versa.
By tomorrow afternoon, the upper-level low will be over eastern NM
giving it a favorable position to enhance precip across much or all
of the CWA. As noted, there are differences on how thunderstorms
will evolve tomorrow afternoon though there is a tendency for the
least amount of precip to occur across the greater El Paso area and
the heaviest towards the Gila and AZ border where a flash flood
watch remains in effect. The main threat with any storms will indeed
be heavy rain and flash flooding, even for those areas east of the
watch. With the increased clouds and precip, highs tomorrow will
cool a few degrees from today.
&&
34
.LONG TERM...
The upper low mentioned by the short term forecaster will maintain
the thunderstorm scenario as it passes over NM Saturday, with the
area west of the Rio Grande being favored for heavy rainfall. On
Sunday, storms will decrease over most of the area except west of
the divide as the upper low opens up and attacks AZ. Meanwhile
the upper high will strengthen and become centered over the
central plains states next week. Initially this will lower the
moisture content and heat up the max temps somewhat, with storm
coverage scattered in the mountains and isolated in the lowlands.
At the end of the forecast period (next Thursday) the models are
bringing toward us an inverted trough from a lower latitude than
the current system, so perhaps there will be another upswing in
convective activity then. That would be a noisy send-off.
Wait. What do I mean by send-off? Well, this is my final forecast
discussion before retirement in about a week. It`s been awesome
serving the Borderland, and the staff of this office will continue
to serve you well if not better. Meanwhile, I obtained permission
from the FGZ MIC to live in his CWA, so I should be fine. Bye!!!
&&
01
.FIRE WEATHER...
The rest of this afternoon will be fairly quiet for most locations
with isolated storms possible east and scattered storms more likely
west, across the Gila and southwest NM. An approaching upper-level
low will bring an increase in moisture as well as foster more
thunderstorms. Widespread storms are likely across the Gila tomorrow
and portions of the western lowlands. Storms will be more scattered
in nature elsewhere. Heavy rain and flash flooding will be the main
concerns. Thunderstorm chances peak on Friday, but a typical
monsoonal pattern will continue the rest of the period.
With the increased moisture and slightly cooler temperatures, min RH
values will be higher than today for tomorrow with values dropping
into the mid 30s. Winds, away from thunderstorms, will top out 10 to
15 MPH and vent rates will vary but generally range good to
excellent for most locations.
&&
34
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 70 88 70 88 / 30 50 50 50
Sierra Blanca 65 84 64 83 / 20 30 40 40
Las Cruces 66 87 66 85 / 30 60 50 70
Alamogordo 68 88 65 86 / 30 60 50 60
Cloudcroft 50 66 48 65 / 30 70 50 70
Truth or Consequences 68 86 65 83 / 40 80 70 80
Silver City 59 76 60 75 / 50 80 80 90
Deming 67 86 64 84 / 30 70 70 80
Lordsburg 71 80 64 79 / 40 80 70 80
West El Paso Metro 76 89 70 87 / 30 50 50 60
Dell City 62 90 66 89 / 20 30 40 40
Fort Hancock 70 90 68 89 / 20 40 40 40
Loma Linda 65 80 63 81 / 30 40 50 50
Fabens 68 88 69 88 / 20 40 40 40
Santa Teresa 70 87 66 86 / 30 50 50 60
White Sands HQ 67 86 68 84 / 30 60 60 60
Jornada Range 64 85 66 83 / 30 60 60 70
Hatch 68 88 66 84 / 30 70 60 70
Columbus 65 86 66 83 / 30 60 60 70
Orogrande 68 87 66 86 / 30 50 50 60
Mayhill 53 77 54 75 / 30 60 50 60
Mescalero 55 76 53 75 / 30 70 50 70
Timberon 49 74 51 73 / 30 60 50 60
Winston 56 79 56 76 / 50 80 80 90
Hillsboro 62 83 62 79 / 40 80 70 80
Spaceport 64 85 65 82 / 30 70 60 70
Lake Roberts 52 77 55 75 / 50 80 80 90
Hurley 61 79 60 78 / 40 80 70 90
Cliff 64 82 58 83 / 50 80 80 90
Mule Creek 57 77 61 78 / 50 80 80 90
Faywood 63 81 61 77 / 40 80 70 80
Animas 69 82 63 79 / 50 80 70 90
Hachita 66 81 63 80 / 30 80 70 80
Antelope Wells 64 83 63 80 / 50 80 70 90
Cloverdale 64 76 60 73 / 50 80 70 90
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...Flash Flood Watch from Friday morning through late Saturday
night for NMZ401>408.
Flash Flood Watch from Friday morning through late Friday night
for NMZ414>416.
TX...None.
&&
$$
34-Brown/01-Fausett/29-Crespo
Area Forecast Discussion
National Weather Service Wilmington NC
945 PM EDT Thu Jul 22 2021
.SYNOPSIS...
A weak front will meander across the area for the next several
days. Isolated showers and thunderstorms will be possible along
the afternoon sea breeze each day through Sunday. Rain chances
will increase next week ahead of cold front.
&&
.UPDATE...
Convection easing. A brief FLS was needed earlier for interior
NE SC earlier, where up to 4 inches may have fallen in farmland
between Lambert and Trio South Carolina, where extensive rice
was grown `back in the day`. Up to 1.5 inches fell near Leland
with Waterford checking in with 1.52 inches of rain from low-
topped CBs and light steering wind. Clearing overnight, patchy
fog or stratus late the expectation.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
Yesterday`s cold front has certainly done its work as evident by
the 12Z MHX RAOB`s PW value of 1.33" (yesterday morning 2.14"). Its
a rare thing here in July to not only be talking about a lack of
convection but also cumulus clouds, who`s development has been
hindered by the smoke plume coming at us from the northwest. Just a
few shallow convective elements have managed to develop along
southern Williamsburg and Georgetown Counties where the moisture is
a little deeper and the convective-stifling smoke is far less
present. Dry northwesterly mid level flow continues tomorrow and our
only chance for convection appears to be isolated storms that move
into western zones after having formed in the Piedmont trough. Given
the overall little change in trajectories aloft suspect that the
smoke will still be around, an idea supported into the morning by
the HRRR vertically integrated smoke product.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Mid level ridging extending in from the west will mostly
dictate dry and seasonable conditions through the weekend. Some
guidance is still showing some convection daily just to the west
of the area but somewhat weakly forced which makes the trek
into our area of responsibility difficult. Highs will be in the
lower 90s each afternoon although slightly higher Sunday with
lows around 70 or so.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
The pattern will slowly transition to a more unsettled
nature with east coast troughing and of course a slow moving cold
front. The GFS suite is a bit more unsettled when compared to the
ECMWF therefor a modest increase in pops daily is appropriate.
Temperature forecast leans a little higher than seasonal values but
not exceedingly so.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR. Convection locally to dissipate by 1-2z, with SKC or SCT090
most areas. MVFR VSBY and CIG possible between 9z-12z in mist
and chunks of stratus, otherwise VFR with light winds. Winds
becoming SE 8-12 knots in afternoon, higher gusts by the coast,
TSTMs to remain limited in coverage, but a few could be strong.
Extended Outlook...Isolated SHRA/TSRA, and brief periods of MVFR
mist.
&&
.MARINE...
Through Friday Night: Very quiet marine conditions expected as
no appreciable pressure pattern becomes established following
Wednesday`s frontal passage. Dominant seas will be a 2-3ft wind
chop with a much lesser 7-10 second swell trying to become
established out of the southeast.
Saturday through Tuesday:
Overall a typical summer pattern will prevail across the
waters with a southerly component to the winds, mostly southwest
especially in time with speeds ten knots or less. With the
deliberate pattern change winds may increase to a range of 10-15
knots late. Significant seas will be mostly 2-3 feet.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...Coastal Flood Advisory until 11 PM EDT this evening for NCZ107.
MARINE...None.
&&
$$
SYNOPSIS...ILM
UPDATE...08
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MJC
MARINE...MBB/SHK
Area Forecast Discussion
National Weather Service Lincoln IL
851 PM CDT Thu Jul 22 2021
.SYNOPSIS...
Issued at 245 PM CDT Thu Jul 22 2021
Scattered showers and a few storms remain possible through early
evening mainly across the areas along and north of I-72. The heat
and humidity build in starting tomorrow, but especially Saturday and
Sunday when heat indices surge into the 95 to 105 range. Additional
chances for storms are possible Friday afternoon across east-central
IL and again Saturday night into Sunday.
&&
.UPDATE...
Issued at 850 PM CDT Thu Jul 22 2021
No major changes to the forecast this evening. Last couple showers
will continue to fade over the next hour or so with dry conditions
expected overnight. Patchy fog development will again be possible,
especially across east central Illinois closest to the ridge axis
where winds are lightest.
&&
.SHORT TERM...(This evening through tonight)
ISSUED AT 245 PM CDT Thu Jul 22 2021
Surface analysis early this afternoon has surface high pressure
located over the lower Great Lakes Region with a washed out surface
boundary draped across northern IL. Further west, upper ridging
remains in place with northwest flow positioned aloft. A weak
shortwave trough stretched from eastern IA into central WI is
sinking southeast with small bits of vorticity out ahead of it. This
paired with steepening lapse rates and daytime heating has resulted
in the development of a few scattered showers and storms across
parts of central IL. Activity will likely linger through early
evening, but should wane with the loss of daytime heating. Hazy,
smoky conditions remain in place area wide as western US wildfire
smoke continues to follow the clockwise flow of the upper ridge and
spill into the Midwest states. Some of this smoke has worked it`s
way down to the surface as of yesterday, which has resulted in spots
of the area being classified in the unhealthy for sensitive groups
air quality category. The HRRR smoke model depicts near surface
smoke sticking around through at least Friday, though it may clear
out later Saturday with the arrival of a cold front (more on that
below).
.LONG TERM...(Friday through Thursday)
ISSUED AT 245 PM CDT Thu Jul 22 2021
Upper ridging falls over east into the Midwest states going into
Friday as a low moves into central Canada. This will act to push the
surface high into the eastern Great Lakes Region, turning surface
flow more southwesterly. This will bring in much warmer temperatures
and higher dewpoints in the low to middle 70s, which will send heat
indices into the 95 to 105 range. The aforementioned upper low will
send a cold front through the Great Lakes Region and points south
Saturday night into Sunday, bringing our next chance for showers and
storms. With high heat and humidity, instability will be plentiful.
However, forecast soundings do show the area somewhat capped with a
warm nose aloft. Therefore, at this time the threat for a few strong
to isolated severe storms looks to remain northeast of the area. As
the front moves through, it may act to clean out some of the near-
surface smoke lingering around. However, the hazy, milky look to the
sky from wildfire smoke high up in the atmosphere will likely remain
through the entirety of the long term period as large-scale ridging
remains in place over the western CONUS. Temperatures next week look
to be be seasonably warm, daily maximum heat indices in the 90s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 639 PM CDT Thu Jul 22 2021
Widely scattered showers and a few storms are in place this
evening but should diminish after sunset. Overnight, haze and
possible some patchy fog development late may restrict visibility
into the MVFR category at times. Any visibility restrictions
should improve mid to late morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Deubelbeiss
SYNOPSIS...NMB
SHORT TERM...NMB
LONG TERM...NMB
AVIATION...Deubelbeiss
Area Forecast Discussion
National Weather Service North Platte NE
631 PM CDT Thu Jul 22 2021
.SHORT TERM...(This evening through Friday night)
Issued at 331 PM CDT Thu Jul 22 2021
West to northwest flow aloft continues across the region as upper
level high pressure remains anchored across the Four Corners region.
Little support for precipitation chances tonight, nevertheless some
CU developing in a fairly moist upslope flow regime across the
northern Panhandle this afternoon. HRRR and HREF do hint that an
isolated thunderstorm cannot be ruled out very late this afternoon
into the early evening across the northern Panhandle and perhaps
into northwest NE. If these develop they should quickly die as we
head toward sunset. On Friday a weak shortwave will cross the
Dakotas. The upper ridge will flatten a bit as this occurs and a
weak cold front will move south into NE as the shortwave passes.
Temperatures aloft will cool a couple of degrees which helps weaken
the capping inversion. A few thunderstorms appear possible late
Friday afternoon into Friday night with the frontal boundary draped
across the area. A stronger storm does appear possible as low-level
moisture pools in the vicinity of the weak front. As a result the
NAM does develop a narrow corridor of decent CAPE with about 20-30kt
0-6km Bulk Shear right near the front. Mid-level lapse rates are
only marginally steep, and with the warm temperatures aloft the
threat for hail seems low with gusty winds the main threat. As far
as the heat, temperatures and dew points are similar Friday as to
what was seen today, and this again puts heat index readings in the
upper 90s which is just shy of heat advisory criteria.
.LONG TERM...(Saturday through Thursday)
Issued at 331 PM CDT Thu Jul 22 2021
Sunday the front lifts northward as a warm front. Somewhat better
low-level moisture and shear will be in place as the front lifts to
the north. This day is uncertain regarding thunderstorm potential
however. A weak perturbation appears that it could move into the area
from the west early Sunday morning with the potential for widespread
mid-level cloudiness and even some isolated shower/thunder
potential. This seems reasonable as mid-level monsoonal moisture
rotates around the Four Corners upper ridge. If this were to occur
SFC based instability could be greatly affected and curtail much
chance for stronger storm development near the warm front. Monday
and beyond the upper ridging builds into the Western High Plains and
eventually the Central Plains. Very warm temperatures aloft will
accompany this with little or no chance for precipitation and
continued hot temperatures. Highs both Tuesday and Wednesday could
be near or exceed 100F.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 627 PM CDT Thu Jul 22 2021
VFR conditions should prevail over the next 24 hours across
western and north central Nebraska. Gusty southerly winds in
northern Nebraska this evening will decrease after sunset. Winds
across the area will become light tomorrow morning. Southerly
gusts will redevelop later tomorrow morning in southwest Nebraska
including KLBF, lasting into the afternoon. A few thunderstorms
are possible tomorrow evening in the northern Panhandle, but are
not expected to impact either terminal at this time.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Taylor
LONG TERM...Taylor
AVIATION...Meltzer
Area Forecast Discussion
National Weather Service Louisville KY
1036 PM EDT Thu Jul 22 2021
.Forecast Update...
Issued at 1035 PM EDT Thu Jul 22 2021
Another quiet night across the area as high pressure continues to
hold sway over the region. Latest surface analysis places the 1024mb
high pressure center over Lake Huron with a quasi-stationary
boundary draped W-E across the southern TN border. Current
temperatures across the CWA are in the upper 60s to low 70s with dew
points in the low 60s across the Bluegrass region and in the upper
60s across our western counties.
With little change to the overall pattern, patchy morning fog will
again be possible especially across our southern and western
counties. Also, haze will continue aloft as NW flow continues to
advect smoke from western US wildfires. But do expect less surface
based haze as high pressure drifts to the NE resulting in an E to
ESE flow across most of the area. Latest HRRR-NCEP Smoke Vertically
Integrated Smoke product continues to show high concentrations over
the region, but the 1000ft AGL product shows little to none over us.
Forecast soundings show a mixing layer up to around 4kft tomorrow
afternoon, so it would be possible to see a little low-level
haziness across SW Indiana and western KY.
Otherwise, the only changes made to the forecast were the addition
of a few hours of patchy fog and a refresh to the near-term grids.
Updated products forthcoming.
&&
.Short Term...(This evening through Friday)
Issued at 305 PM EDT Thu Jul 22 2021
Sfc high pressure spreading across the entire Ohio Valley will
continue to influence dry and quiet weather across our region. Upper
level NW winds will continue to filter thick smoke into our region
aloft, as suggested by the HRRR Vertically Integrated Smoke guidance.
However, ENE winds at the sfc have helped partially clear out near-
sfc smoke. NE sfc winds continuing tomorrow should help improve low
level conditions, but HRRR Near-Surface Smoke guidance does suggest
we`ll still at least have some smoke around tomorrow, mostly
concentrated to our west and south however. It likely won`t be as
thick as in recent days.
For tonight, temps will range from low to mid 60s, with our coolest
locations expected to be across the Bluegrass region. We could even
have a few isolated places dip into the upper 50s. Some early
morning patchy fog is possible, except for the quadrant of our CWA
that is both north of the Bluegrass Pkwy and east of I-65. For
tomorrow, another dry day as high pressure keeps mostly sunny sky
cover with some haze. Afternoon temperatures are forecast to reach
the mid-upper 80s.
.Long Term...(Friday night through Thursday)
Issued at 311 PM EDT Thu Jul 22 2021
Friday Night through Sunday Night...
Moving into the weekend, upper trough axis over New England is
forecast to move off shore. However, a northwest flow aloft will
continue across the Ohio Valley. Surface high pressure is forecast
to be to our east and a southerly return flow event will unfold
bringing higher amounts of moisture and heat to the western sections
of the Ohio Valley.
As we warm up and become more humid, the chances of
afternoon/evening convection will increase. The overall coverage
for Saturday looks to be relatively small. Model soundings show a
decent capping inversion holding through much of the day. However,
I can`t rule out some showers/storms down along the KY/TN border
perhaps arcing back into Western KY. Lows Friday night will be
mild with lower-mid 60s over the Bluegrass and mid-upper 60s
elsewhere. Highs Saturday should warm into the upper 80s to perhaps
the lower 90s. Ongoing smoke layer aloft may end up keeping temps a
little cooler than current guidance suggests.
On Sunday, convective chances look a bit better as the capping will
be much less weaker as mid-level perturbation and weak frontal
boundary push into the region from the north. While shear remains
generally weak across the area, we`ll have plenty of instability to
work with, so I expected more widespread convection Sunday
afternoon/evening across the region. Based on projected model
soundings, heavy rainfall (given high PWAT values), gusty winds, and
lightning will be the primary weather hazards. After morning lows
in the upper 60s to the lower 70s, highs Sunday should warm into the
upper 80s to the low 90s.
Monday through Thursday...
Moving into next week, the guidance remains in general agreement
with keeping a decent amount of ridging over the western US while a
baggy trough axis remains across the eastern third of the US.
Frontal boundary from Sunday may get hung up across the southern
Ohio and northern Tennessee Valleys and that could keep higher
chances of afternoon/eve convection across the region. This frontal
boundary may get pushed a bit further south on Tuesday resulting in
a drier day.
By mid-late week, a large ridge should continue to develop while
being centered out in the inter-mountain west. The global models
want to expand that ridge a bit further east as the week goes on.
Our region will remain on the eastern periphery within the
notorious NW flow pattern. Perturbations within this flow regime
could send a series of MCS`s our way, though the overall pattern may
keep much of this in the Midwest and into the southern Great Lakes.
Given the overall tendency of the models being too fast with
building heat ridges east this summer, the last few runs of the Euro
may be too quick with this evolution by a few days or so. So, given
the pattern, at least some slight to chance PoPs are warranted for
the mid-late week period. There does seem to be a bit less
variability in the upper level pattern for the late week and into
next weekend time frame where the ridge axis may get a good run of
expanding eastward into the Ohio Valley. Should that be the case, a
much warmer and drier pattern can be expected.
Highs Monday/Tuesday should average in the upper 80s to the lower
90s with overnight lows around 70. Wednesday and Thursday`s temps
should generally average in the lower 90s with overnight lows in the
lower 70s.
&&
.Aviation...(00Z TAF Issuance)
Issued at 721 PM EDT Thu Jul 22 2021
Expect mostly VFR conditions throughout the period with the
exception of MVFR fog potential at BWG and HNB early Friday morning.
Otherwise, winds will be light out of the E to ESE with a SCT mid
cloud deck throughout the day Friday. Surface VIS will remain
unrestricted Friday, but haze aloft due to western US wild fires
will likely continue as a result of NW flow above 12kft.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update...CG
Short Term...CJP
Long Term...MJ
Aviation...CG
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
936 PM CDT Thu Jul 22 2021
.UPDATE...
936 PM CDT
For the rest of tonight, it appears the chances for any convection
of note are diminishing. In the warm and moist air mass, we`ve
seen widely isolated showers pop up at times, though as of this
writing, only seeing a lone cell south of Pontiac. A weak short-
wave centered near the southeast MN, northeast IA border will
drift south-southeast through the night. Meanwhile, a slightly
stronger wave over north central WI, responsible for higher
coverage of showers and thunderstorms will give only a glancing
blow of forcing to northeast IL and northwest IN overnight, with
the stronger forcing passing into lower MI.
00z RAOBs showed a pronounced dry layer above 700 mb and most
recent AMDAR soundings also indicated a weak inversion around 600
mb. Meanwhile, despite the very muggy boundary layer with low to
mid 70s Td, lacking better saturation in the 900-800 mb layer on
aforementioned soundings, where a theoretical elevated parcel
could lift from to tap into MUCAPE, also appears to point toward a
struggle to generate robust enough updrafts for lightning
generation. Thus, with only modest forcing and rather unfavorable
profiles, kept thunder mention at slight chance through the night.
For this update, kept the 30-40% PoPs into northeast IL and far
northwest IN, though looking like that may be a bit generous. Some
widely scattered lighter showers may be all that ends up occurring,
if that. Recent HRRR runs have fully backed off on activity, while
3km NAMnest has a few isolated cells over Chicagoland overnight.
The only other forecast change of note was to have haze mention
from effects of lower level wildfire smoke to areas where there
were recent minor visibility reductions. On Friday, southwest flow
looks to bring a higher concentration of low-level smoke to the
region per the 00z HRRR surface smoke forecast, so added haze
mention through Friday night to the grids. Subtle forcing toward
mid day Friday into the afternoon and lake breeze convergence
hugging the shore may be just enough to pop isolated to widely
scattered showers and thunderstorms.
Castro
&&
.SHORT TERM...
248 PM CDT
Through Friday night...
Southwesterly flow is pumping in warm. moist air, with dewpoints
jumping from the mid-60s this morning to the lower 70s as of
writing. Clouds and haze from smoke has scattered out in many areas,
allowing temperatures to climb into the low to mid 80s. Temperature
differential has allowed the lake breeze to set up and move inland,
just east of O`Hare at this moment, and is expected to move just
west of the main airports, shifting winds to the southeast, and
helping keep locations near Lake Michigan a bit cooler in the upper
70s.
Increased heat and moisture is reflected in isentropic upglide,
allowing for a slightly unstable atmosphere, as reflected with
occasional showers moving through the forecast area. With CAPE
values in excess of 1000 J/kg, the potential for isolated
thunderstorms to fire this afternoon exists, although they should be
isolated in nature.
A short wave/vorticity max will move out of northern Iowa and may
provide focus for increased convective activity Thursday night into
early Friday morning. Guidance is not in agreement with the location
of this increased chances, but presently appears to be focused along
the Wisconsin/Illinois border, especially northeast Illinois. The
short wave will move east Friday morning, but with continued
southerly flow pumping in warm, moist air, instability will remain
throughout Friday for a continued slight chance of isolated showers
and maybe even a thunderstorm or two to fire Friday afternoon. High
temperatures will be in the mid to upper 80s, although the heat
indices will be in the lower 90s.
Chances for precipitation decrease Friday overnight, but continued
southerly flow will keep dewpoints in the lower 70s, with lows
Saturday morning in the lower to mid 70s.
BKL
&&
.LONG TERM...
256 PM CDT
Saturday through Thursday...
No substantial changes to the forecast for this weekend into the
middle of next week as seasonably summertime conditions with
intermittent chances of thunderstorms continue.
Broad ridging centered across the central and southern High
Plains will remain established through the forecast period,
keeping the western Great Lakes on its northeast fringe.
Seasonably warm and humid conditions will be the rule for northern
Illinois and northwest Indiana. While the greatest convective
chances through the period will remain northeast of the forecast
area, the most favorable period for storms to edge southwest into
the area will be late Saturday afternoon and night, and possibly
into Sunday.
Saturday and Sunday: Low-level moisture will continue to increase
through the day Saturday on southwest winds sporadically gusting
to 25 mph. While some guidance may be overdone with forecast dew
points into the upper 70s, widespread dew points solidly in the
low 70s and edging into the mid 70s is likely. With these dew
points, the environment should remain capped through much of the
day under an 850 hPa warm nose. We will have to monitor any
potential upstream convection on Friday night, however, as there
are some signals a residual MCV may track within faster WNW mid-
level flow just north of the area and bring either enhanced mid-
level clouds/decaying showers (assuming the expected stronger cap)
to northern Illinois late morning/early afternoon.
The increase in dew points combined with temps potentially into
the low 90s will result in heat index values around 100F in the
afternoon. If mid-level cloud cover and any potential smoke aloft
is minimal, slightly higher temps and heat index values nearing
the local Heat Advisory criteria of 105F are possible.
Capping may erode enough ahead of an approaching cold front to
allow for isolated to scattered convection to develop over
primarily northeast Illinois and northwest Indiana Saturday
evening. A highly unstable environment with modest 0-8km shear
(better metric due to potentially very tall storms) of 25-30kts
will support explosive convective growth and a resultant severe
thunderstorm wind risk with any convection that does develop.
The southward push of the cold front or effective outflow boundary
will depend on the amount of upstream convection on
Saturday/Saturday night. While guidance has been fairly persistent
on clearing the boundary through most, if not all, of the CWA by
Sunday afternoon, any slower progression will support another
afternoon of isolated explosive severe thunderstorm potential
across southern portions of the forecast area. Additionally, heat
index values will near or surpass 100F again around and even
behind the boundary ahead of somewhat drier air advecting in from
the north.
Monday through Thursday: The latest GFS is a bit of an outlier in
bringing additional rounds of convection across the area with WNW
flow aloft on Monday and again on Tuesday, likely owing to
unrealistic amounts moisture (dew points nearing 80F) in then
lowest 500ft of modeled profiles. With surface high pressure
setting over the region and the weekend`s boundary drifting south
on renewed convection each day, Monday and Tuesday will likely
remain dry and warm. A more pronounced wave should bring
increasing chances for convection Wednesday into Thursday.
Kluber
&&
.AVIATION...
For the 00Z TAFs...
Aviation Forecast Concerns:
* Some low VFR/high MVFR visibility in haze for metro terminals
this evening.
* Low probability for SHRA/TSRA late tonight/pre-dawn Friday.
Somewhat ill-defined surface warm front extended from southern
WI, southeast along the lake breeze boundary west of ORD/MDW and
then southward near the IL/IN state line early this evening. This
front will continue to evolve slowly northward overnight. While a
few isolated showers had developed along this boundary across the
Chicago metro this afternoon, a lack of stronger forcing should
keep things quiet across the terminals through this evening.
Various model guidance continues to depict the potential for some
convective development primarily across southeastern WI later
tonight along/north of the warm frontal boundary, on the nose of a
modest southwesterly low level jet and in association with a weak
mid-level short wave which will track southeast across the
region. With a southeasterly propagation expected to any
showers/storms which develop over southeast WI, the potential does
exist for some of this to affect the Chicago metro terminals
after midnight, generally in the 06-11Z period based on CAM
solutions. Confidence in any significant coverage this far south
across the terminals is fairly low, with better chances north and
northeast of the terminals across WI/southern Lake Michigan on the
nose of the jet and with a little better mid-level moisture
profile. Felt it prudent to leave some mention for now though and
since can`t use the inherited prob30 (only allowed beyond first 9
hours of TAF) have carried a VCSH mention at this time and will
monitor for development across WI later this evening to assess
the potential for our forecast area.
On Friday, the mid-level wave will track off to the east and an
upper level short wave ridge is progged to build across the
western Lakes region. Warming mid-level temps due to subsidence
beneath this ridge looks as if it will generally provide a capping
inversion with respect to renewed convection. Some guidance
weakens this cap a bit late in the day and suggests some isolated
convective threat, though feel that this is a fairly low coverage
and low probability occurrence at any particular terminial and
thus will maintain dry TAF Friday/Friday evening.
East-southeast winds for ORD and MDW will become light southeast
later this evening and then light south-southwest overnight.
Modest south-southwest winds Friday should keep lake breeze
boundary east of ORD/MDW. Only other concern is with current
patchy low-end VFR visibility in haze across parts of the Chicago
metro. Expect this may improve as winds turn southerly overnight.
Ratzer
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
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Area Forecast Discussion
National Weather Service Marquette MI
627 PM EDT Thu Jul 22 2021
.SHORT TERM...(This evening through Friday)
Issued at 406 PM EDT THU JUL 22 2021
A shortwave continues to bring scattered showers and mostly cloudy
skies over the U.P. today. Convection so far has been mostly limited
to shower activity today, with the west being the most likely area
to have anything hit the ground as RAP soundings do show a dry layer
in the lower levels of the atmosphere. Limited instability and weak
bulk shear magnitudes make convection possible for this evening, but
not likely; therefore, only a slight chance of thunderstorms was
included across the west this afternoon into early tonight.
Meanwhile, isolated to scattered showers are possible in the western
and central U.P. today and tonight, although not so confident on all
the precipitation getting to the ground, particularly in the central
areas. Temperatures were a little warmer than expected today,
probably due to some breaks in the cloud cover (and maybe the WAA
into the U.P. was stronger than expected?).
For tonight, thinking there still might be a slight chance for
showers and thunderstorms across the western area, as some model
guidance has some light convection hanging on throughout the night.
The reasons for including slight thunderstorms is that some model
guidance holds onto some MUCAPEs around 500 J/kg. When combined with
the information that another shortwave is approaching, and our
location still being in the right entrance region of an exiting jet
streak, thought a slight chance of thunderstorms was possible
tonight across the west. Models have trended down cloud coverage;
therefore lowered temperatures slightly tonight (there is still
slight WAA aloft). Some upslope flow from the north Bay of Green Bay
may bring some foggy conditions to the south central areas late
tonight.
Friday looks to be warmer, as WAA continues to move into the area.
Another shortwave should move over us ahead of an approaching cold
front from the Canadian Prairie northwest of us. Have a slight
chance for showers and thunderstorms during the morning hours for
the western half as some model guidance showed some light
precipitation occurring. These slight chances might be removed later
as CAMs are now showing hardly any precipitation until the afternoon
hours though. Could see some scattered showers and thunderstorms in
the western half Friday afternoon ahead of the cold front. Severe
weather potential doesn`t look too promising ahead of the cold
front; bulk shear magnitude is unimpressive and MUCAPE only reaches
to around 1000 J/kg. Otherwise, temperatures may get hot out in the
west, as WAA and lesser cloud cover could bring temperatures to the
upper 80s across parts of the west.
.LONG TERM...(Friday night through Thursday)
Issued at 320 PM EDT THU JUL 22 2021
Overall upper pattern for the next week will be dominated by broad
upper ridging over the intermountain west and central/northern
plains. Low amplitude mean troughing will remain over far eastern
North America. The Upper Great Lakes will remain on the eastern
fringes of the large heat dome over the central U.S. with above
normal temperatures expected for much of the period from this
weekend through next week. Occasionally, a shortwave cresting the
upper ridge will push a weak front southward across the U.P. and
northeastern U.S. providing some cooling...mainly lowering
temperatures back to just above normal vs. uncomfortably warm.
Any rain chances will be tied to these shortwaves/fronts. The highest
likelihood for much needed rain over the next 7 days will occur
Friday night into Saturday. Shortwave/front moving east along the
Canadian border will initiate a cluster of showers and thunderstorms
over northern MN Friday afternoon that will then move southeastward
across the area Friday night exiting the eastern U.P. Saturday
morning. While thunderstorm intensity will wane through the night
with marginal shear values and loss of low level instability...PWs
close to 200 percent of normal will yield some locally heavy rain.
The surface trough/front will likely clear the area by Saturday
afternoon but if it gets hung up near the Lake Michigan lake breeze
there could be a couple of storms that pop up Saturday afternoon. In
addition...breezy southerly winds up Lake Michigan will result in
high swim risk conditions along Schoolcraft County beaches on
Saturday.
Sunday and Monday look dry and warm before next shortwave brings at
least a chance of a few showers and thunderstorms Monday night into
Tuesday. Then dry and warm again for midweek next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 627 PM EDT THU JUL 22 2021
VFR conditions will continue at IWD and CMX through the forecast
period. SAW will have MVFR clouds early and will then stay VFR
through most of the rest of the forecast period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 406 PM EDT THU JUL 22 2021
Some northeasterly winds 20 to 25 knots are possible this afternoon
and early this evening near Duluth, MN. Otherwise, expect winds to
be 20 knots or less over the lake for the forecast period, save for
some southerly winds over the eastern lake possibly getting up to 20
to 25 knots Friday night.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...TAP
LONG TERM...MZ
AVIATION...07
MARINE...TAP
Area Forecast Discussion
National Weather Service New York NY
1028 PM EDT Thu Jul 22 2021
.SYNOPSIS...
Weak high pressure builds towards the area through Friday, with
weak disturbances passing through this evening and Friday. High
pressure builds in for Saturday with a frontal system
approaching Saturday night and into Sunday. The frontal system
may linger in the area through the beginning of next week. Weak
high pressure builds in for Tuesday with another frontal system
approaching by midweek.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A light southwest flow along the coast has kept dew points in
the lower to mid 60s while inland areas, under near clear and
calm conditions, have fallen into the mid and upper 50s. Updated
temperatures, dew points, and winds for current condition and
overnight trends.
Mean northern stream upper troughing continues over the region
through the end of the week. An embedded weak shortwave moves
east this evening, with a stronger shortwave approaching Friday
morning.
Perhaps a window for radiational cooling late tonight in wake of
this shortwave, and ahead of next approaching shortwave, but appears
a combo of mid and high clouds will limit this potential. Lows in
the 50s across far outlying areas, and 60s for urban centers and
coast.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
More vigorous shortwave energy pivots through the region on
Friday, with associated surface trough sliding through the
region in the afternoon. Shortwave lift, in a marginal unstable
and weak shear environment, will trigger potential for
isolated/scattered shra/tsra Friday afternoon across the
interior hill terrain and mountains to the north, sinking south.
Highest probability (30%) across interior southern CT.
Otherwise another seasonably warm (lower to mid 80s) and
relatively comfortable day. Morning sunshine will give way to
sct (coast)-bkn (interior)instability cu in the afternoon, while
modest NW flow should limit seabreeze development to late day
and mainly for s coastal areas. HRRR smoke product indicating
the bulk of the smoke plume aloft will move south of the region
on Friday.
Shortwave and mean trough axis slide east Friday Night, with
surface high pressure building in from the west. This should
allow for clearing skies and diminishing NW flow. Potential for
some good radiational cooling well down into the 50s for
Interior locations, with generally 60s elsewhere.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A weakening in the upper-level trough will allow for surface
high pressure to take control of the area on Saturday with
temperatures in the low to middle 80s. A mid-level disturbance
approaches by Saturday evening and the associated cold front
pushes into the area by Sunday. The chance for showers should be
expected with the convective activity dependent on the exact
timing of the front, however, models indicate that there will be
enough instability by Sunday afternoon to support some
thunderstorm development.
The upper level trough attempts to reestablish itself during
the beginning of the week. At the surface, the front looks to
stall near the area. This may be a focus for some additional
showers (and thunderstorms during the afternoon and early
evening) on Monday as well. Depending on where exactly the front
stalls, SW flow on Monday may allow for high temperatures to
rise into the upper 80s and low 90s.
Weak high pressure may build in on Tuesday as the front pushes
a little more to the south, but there is some disagreement in
global models as to how strong the high is and exactly how far
south the front moves. Generally though Tuesday is kept dry.
Another frontal system looks to move into the area mid-week but
once again the timing of its approach and passage varies from
late Wednesday through early Friday.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
High pressure builds in from the west through Friday, and
remains over the terminals Friday night.
VFR through the TAF period.
Winds NW 5 to less than 10 kt through the overnight, with a few
outlying terminals light and variable. Winds NW less than 10 kt
Friday, with afternoon sea breezes at KJFK, KISP, KBDR, and
KGON.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected. A sea breeze is likely
Friday afternoon at KJFK.
.OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.Friday night-Saturday...VFR.
.Sunday-Monday...MVFR or lower possible with a chance of showers and
thunderstorms.
.Tuesday...VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Minor update to the ocean seas which were about a foot too high
in a few locations.
Winds and seas are expected to remain below SCA criteria
through the Saturday Night in a weak flow regime. Winds and
waves on the ocean approach SCA threshold on Sunday ahead of a
frontal system. Seas remain elevated through much of the day on
Monday before falling below SCA threshold by Monday night. Sub-
SCA conditions are expected thereafter in the mid- week.
&&
.HYDROLOGY...
No hydrologic impacts are expected into next week.
&&
.TIDES/COASTAL FLOODING...
Astronomical tide levels continue to rise with the approach of a
full moon on Friday.
Isolated minor coastal flooding along the western south shore
bays seems likely with the evening high tides cycles Friday and
Saturday.
A general low to moderate rip current risk continues at the
ocean beaches through Saturday. The moderate risk will be
particularly around the times of low tide, due to the higher
tidal range with the upcoming full moon.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...NV/MW
NEAR TERM...MET/NV/MW
SHORT TERM...NV
LONG TERM...MW
AVIATION...MET
MARINE...MET/NV/MW
HYDROLOGY...NV/MW
TIDES/COASTAL FLOODING...NV/MET
AREA FORECAST DISCUSSION
National Weather Service Charleston WV
1016 PM EDT Thu Jul 22 2021
.SYNOPSIS...
High pressure continues to hold over the area into the weekend.
Moisture increases Sunday, ahead of a cold front that crosses
Monday. High pressure may arrive for the middle of next week.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 1015 PM Thursday...
Forecast continues to remain on track.
As of 720 PM Thursday...
Current forecast remains on track.
As of 252 PM Thursday...
Surface high pressure around the lower Great Lakes will maintain dry
and quiet conditions through this evening. By tonight, light to calm
winds amid a shallow nocturnal inversion should set the stage for
valley fog across parts of the area. However, there is still some
uncertainty with the fog development tonight as models do show that
some potential exists for some high level clouds to move across the
area.
Latest CAMs show convection developing upstream across WI/MI
overnight due to a shortwave embedded in the northwest flow aloft.
As this activity continues to dive southeastward and approach our
area on Friday, expecting this to weaken substantially as it moves
into more stable conditions in our area. Thus, not expecting any
precipitation across the region on Friday despite the aforementioned
shortwave rippling through the area during the day, but this may
still result in an increase in high clouds in the afternoon hours.
Otherwise, temperatures should be slightly warmer tomorrow with
values generally around normal for late July. In addition, with
northwest flow remaining in place, can`t completely rule out
hazy/smoky skies continuing on Friday, which the latest HRRR
vertically integrated smoke parameter seems to suggest at this
time.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 234 PM Thursday...
Surface high pressure will remain in control Friday night into
Saturday. Mostly clear skies and near calm winds will provide very
hot conditions this weekend, with highs reaching 92 degrees at few
spots across the lowlands. Low level moisture will be high
contributing to heat index climbing into the mid to upper 90s at
some spots across the lowlands especially Sunday.
In addition, the HRRR vertically integrated smoke product suggest
areas of smoke/haze will return to our area Friday through the
weekend. Therefore, introduce HAZE to the forecast for this time
frame.
A slight chance for afternoon shower or thunderstorm will be
possible along the eastern mountains, and in interior southeast Ohio
during the weekend due to diurnal heating and orographic effects.
Otherwise, it will be dry. Expect very muggy nights with lows in the
upper 60s.
Any afternoon convection will quickly subside by sunset during the
weekend. There is a slight chance for a weak cold front to spread
additional showers or storms across the middle Ohio Valley overnight
Saturday night.
Central guidance temperatures generally looked reasonable.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 234 PM Thursday...
A cold front arrives during the day Sunday spreading scattered to
scattered showers or storms before exiting east on Monday. Again,
shower/storm activity will depend on the diurnal heating and
convergence along the cold front to produce a heavy downpour. Yet,
another cold front arrive early Monday with additional chances
for showers and storms.
Expect above normal temperatures through the period, with only
a slight dip behind the cold front by midweek.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
As of 728 PM Thursday...
High pressure continues to allow VFR conditions to persist for
much of the period at most sites. However, with mostly clear
skies and relatively calm winds expected tonight, river valley
fog may develop. Any sites that have fog formation tonight could
have MVFR and potentially IFR visibilities. Currently expecting
EKN to have the best chance for fog tonight and this site may
even have visibilities/ceilings lower into the LIFR range.
Any fog that forms will begin to dissipate out tomorrow morning
giving way to VFR conditions for the day tomorrow and through
the end of the period.
Relatively light and variable winds start the period with winds
becoming light to calm tonight. Light and variable winds are
expected to pick back up during the day tomorrow.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Coverage, timing, and duration of valley
fog tonight may vary from forecast.
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 07/23/21
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H M M M M
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H L M M M
PKB CONSISTENCY H H H H H H H H M L L M
CKB CONSISTENCY H H H H H H H H H L H H
AFTER 00Z SATURDAY...
IFR possible with showers thunderstorms on Sunday.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.
&&
$$
SYNOPSIS...ARJ/RG
NEAR TERM...RG/CG
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...CG
Area Forecast Discussion
National Weather Service Blacksburg VA
930 PM EDT Thu Jul 22 2021
.SYNOPSIS...
High pressure will maintain primarily dry and seasonal weather
through Friday. The high will gradually shift to off the southeast
coast this weekend while a front moves in from the northwest.
This will be our next bonafide opportunity for showers and
thunderstorm, especially by Monday.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
As of 930 PM EDT Thursday...
...Comfy and calm conditions tonight with seasonable temps as high
pressure remains nearby Friday...
Little to no change in the current forecast package with the
exception of cloud cover and temperatures. Dewpoints continue to
fall into the mid to upper 50s area wide with air temperatures in
the upper 60s and low 70s. Mid to upper level cirrus continues
to stream through as well with HRRR and NAMnest guidance still
showing some thickening overnight into early Friday morning.
Cirrus will break mid to late Friday morning giving way to milky
sunshine with fair weather puffy cumulus building in the
afternoon hours.
An isolated shower or storm cannot be ruled out
over the North Carolina mountains and back into the highest
peaks of the Greenbrier Valley/Alleghany Highlands. Most
locations will remain dry with departing high pressure and
enough subsidence leftover to suppress any convection from
forming. Better chances for hit or miss storms return for the
weekend ahead.
Previous discussion..
Current forecast package remains on track. A comfortable evening
ahead gives way to another dry day Friday...
Some minor adjustments in regards to temperatures and dewpoints as
drier air pools in from the north. Current mid to upper level water
vapor reflects a good pocket of dry air diving down from the
northwest as high pressure settles in. Dewpoint factors as of 530
PM are generally in the mid to upper 50s north of the US-460
stretch and down into the North Carolina mountains. Elsewhere
values are right around 60 to 63 degrees making for a fairly
comfortable evening ahead.
Milky skies will remain for the remainder of the evening as
upper level cirrus continues to stream in with an upper level
jet streak just to the north across north central West Virginia,
western Maryland, and southwestern Pennsylvania. Hi-res model
guidance continues to suggest cirrus hanging tough and even
thickening a bit after midnight especially in areas north of
US-460. Elsewhere similar conditions look to prevail through
Friday morning so don`t be surprised to wake up to brief
overcast or even milky skies obscuring sunrise/Buck Moon. The
extra cirrus may also limit our overall drop in temperature and
fog development heading into early to mid Friday morning. As a
result, we can expect lows a in the mid to upper 50s west of the
Blue Ridge with low to mid 60s out east. Truly a treat for late
July standards.
Dry conditions continue Friday with cirrus slow to burn off in the
morning and puffy fair weather cumulus in the afternoon. An isolated
shower is possible over the highest ridges of North Carolina as
moisture builds back in on return flow. Subsidence will still rule
the forecast as high pressure sits nearby keeping mostly everyone
dry with highs in the mid to upper 80s.
Confidence remains high in the near term.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 230 PM EDT Thursday...
An upper level trough that is over the region will shift off the
east coast Friday night. Meanwhile, surface high pressure over New
England will wedge south into North Carolina. A combination of a
final shortwave coming around the trough and the boundary of the
wedge moving over the area will bring a chance for showers to the
piedmont counties late Friday night into Saturday morning. As the
center of the high moves offshore in the afternoon, southeast
upslope flow may be enough to generate showers along the eastern
slopes of the Blue Ridge. As these storms build, steering flow will
direct them east into the piedmont in the evening. Any showers or
thunderstorms Saturday are not expected to become strong or severe
and should fade during the evening hours.
On Sunday, an broad upper level ridge centered over Texas and the
western Gulf will begin edging into the area. This system will help
increase temperatures and moisture in the region. Through the day, a
lee trough develops over the piedmont. Showers and thunderstorms are
expected to form along the Blue Ridge and foothills in the afternoon
then again drift east into the evening. Meanwhile, a slow moving
cold front in the Ohio Valley will approach the area late in the
day. A few showers and thunderstorms out ahead of the front may
track across the mountains. With slight better instabilities Sunday,
a few storms could become strong to severe.
Near normal temperatures expected Saturday with upper 70s to mid 80s
across the mountains and mid to upper 80s east of the Blue Ridge.
Highs Sunday will range in the 80s west of the Blue Ridge to low 90s
east. Each night, overnight lows will fall into the 60s.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 230 PM EDT Thursday...
Models continue to display a cold front coming across the region on
Monday, jumping to a lee trough in the afternoon. However, with
zonal flow, timing could be delayed until Tuesday. This front could
stall across the area Monday bringing rain to mainly the mountains,
then moves east with rain mainly to the piedmont Tuesday. Since the
degree of uncertainty is high, will keep chance PoPs in the forecast
with slightly higher numbers Monday. Once the front clears the area,
models agree with dry high pressure settling over the region Tuesday
and Wednesday. A second frontal passage is possible Thursday. High
pressure following this front should keep the region dry going into
the next weekend.
Temperatures ahead of the front will run warmer than normal with the
warmest day being Monday. Following the front, temperatures will
fall back towards normal values Tuesday and Wednesday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
As of 726 PM EDT Thursday...
Good flying conditions are expected to continue with primary VFR
through Friday. A chance remains for pockets of river valley fog to
develop tonight in the vicinity of KBCB and KLWB. For now, the
highest confidence for this remains at KLWB where fog has been an
issue over the last two mornings between the 9z-13z window. Overall
fog may be limited with hi-res model guidance suggesting mid to
upper level cirrus thickening tough at all TAF sites through Friday
morning.
The cirrus should start to diminish by mid to late Friday morning
with pockets of puffy fair weather cumulus at all TAF sites Friday
afternoon. An isolated shower or storm cannot be ruled out in the
vicinity of KTNB to KGSO as moisture slowly returns to the area.
High pressure nearby should keep subsidence in play suppressing any
scattered to widespread convective development until the weekend
ahead.
Winds will remain light out of the north and northwest tonight
through Friday morning before switching to the east and southeast Friday
afternoon.
Confidence remains high for the TAF cycle. Moderate confidence on
river valley fog at KBCB and KLWB based upon the increasing mid to
upper level cirrus deck moving in.
Extended Aviation Discussion...
VFR conditions are expected through much of the upcoming weekend.
Some late night fog at LWB, perhaps BCB may occur. Any other hazards
would be from showers/storms which will become more prevalent when a
frontal boundary moves into the area Sunday into Monday. Drier
conditions are expected by the middle of next week.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...PM
NEAR TERM...ET/PM
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...ET/PM
Area Forecast Discussion
National Weather Service Springfield MO
616 PM CDT Thu Jul 22 2021
...Updated 00Z Aviation Discussion...
.SHORT TERM...(This evening through Friday)
Issued at 249 PM CDT Thu Jul 22 2021
Hazy conditions were occuring across the area Today from the fires
out west. Visibilities were around 5-7 miles across the area. Some
weak energy across Arkansas, combined with increasing moisture
from the south, has allowed for isolated showers and storms along
the Missouri/Arkansas border. Most places will likely remain dry.
Similar conditions are expected for Friday with highs in the
upper 80s to perhaps 90 across western Missouri and southeast
Kansas. Models suggest a slightly better shot at an isolated
shower or storm across the eastern ozarks, where mid level temps
will be cool enough. Otherwise heat index values of 95-100 seem
likely. HRRR smoke tool shows most of the hazy conditions further
east for Friday.
.LONG TERM...(Friday Night through Thursday)
Issued at 249 PM CDT Thu Jul 22 2021
Mid level heights rise for both Saturday and Sunday along with
warming 850mb temps. Therefore highs in the lower 90s and heat
index values around 100 are likely. It appears shortwave energy
will drop into Missouri by Sunday night and Monday. While
ensembles shoe the highest precip chances east of the area, we may
get clipped by some rainfall and the NBM 20-40 percent
probabilities for precip account for this. This may knock a degree
or two off highs for Monday.
Ensembles are in good agreement that the upper level ridge will
move into the central plains and expand next week, creating even
warmer temps (highs in the middle 90s). NBM continues to show the
potential for even higher temps however this will likely be
dependent on how ground cover/vegetation. 850mb temps of 23-25C
would support middle 90s temps.
As far as heat headlines go, none planned at this time. At this
time the highest potential to reach a 105F heat index is on Sunday
however even then we may come up short. By Monday and beyond
however we will likely reach the criteria of 100 deg heat index
for 4 or more days (the prolonged heat impact).
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 615 PM CDT Thu Jul 22 2021
Hazy conditions are expected to continue through this evening with
visibilities reduced to as low as 6 miles at times. Meanwhile, a
few isolated showers are present across the area and will
dissipate after sunset. Most areas will remain dry. Given minimal
coverage, precipitation chances are not being reflected in TAFs.
Winds will be light out of the south through tonight, before
turning more southwesterly on Friday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Burchfield
LONG TERM...Burchfield
AVIATION...Perez