Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/30/22
Area Forecast Discussion
National Weather Service Boston/Norton MA
951 PM EDT Fri Jul 29 2022
.SYNOPSIS...
Weak low pressure tracks south of New England, resulting in
periods of light rain overnight, with steadiest rain over RI and
southeast MA. Not a drought buster, but beneficial rains. Then
dry weather this weekend with warm days, cool nights and
comfortable humidity. Very warm to hot temperatures with
increasing humidity levels anticipated for the upcoming
workweek, with the most oppressive days looking to be Thursday
and Friday. Showers and thunderstorms are possible on Tuesday,
but significant rains are not anticipated and dry weather should
prevail much of the workweek.
&&
.NEAR TERM /UNTIL 5 AM SATURDAY MORNING/...
10 PM Update:
Forecast dilemma remains unchanged, will short wave trough over
Lake Erie this evening have sufficient amplitude to back the
mid level flow to capture deep layer moisture over VA/MD
northward into SNE? 18z guidance continues the theme from the
12z CAMs on a period of steadier rains after midnight across RI
and southeast MA. This is response to a strengthening 850 mb SW
jet over the ocean south of New England, with max moisture and
thermal advection into RI and southeast MA, especially the Cape
and Islands. Previous forecast captures this well, thus no major
changes with this update. Earlier discussion below.
================================================================
Following trends, the 18z guidance and HRRR runs, adjusted
PoP/Wx/QPF for anticipated rains overnight tonight. Changes
essentially focus less QPF north and west of I-95, with similar
or slightly more towards central/southern RI, South Coast, Cape
and Islands.
Axis of surface wind convergence and CAPEs on the order of 1000
J/kg appear the culprits in developing a cluster of scattered
convection across the Berkshires into western Hampshire and
Franklin Counties (with additional development in east-central
NY). Suspect these are probably high-based and while a brief
downpour looks possible given radar trends, with 25-30 degree
dewpoint spreads it certainly could make it tough to generate
much rain.
The dry profiles look to exist thru still a decent depth of the
lower atmosphere across all of SNE. While radar is indicating
showers mainly near or south of Route 6 from Hartford to west of
Providence, falling from lower to mid-based clouds. None of
these showers appear to be reaching the ground but expect that
to change moving toward late evening/midnight with mainly light
rains within a few miles north of I-84 northeastward to the
North Shore. For these locations in interior CT and MA though,
duration of rain looks fairly short and I`ve reduced rain totals
for these areas to a few hundredths to a tenth of an inch. Rain
looks to become steadier across southeast New England and
particularly central/southern RI, South Coastal towns and the
Cape and Islands overnight as convectively enhanced surface wave
low passes over the 40/70 benchmark. Though rain should
predominate, some limited instability (LIs 0 to -1) in fcst
soundings across southeast New England could result in some
thunder and in-cloud lightning flashes as low approaches. Rain
then diminishes by the pre-dawn/early Sat AM hrs. Made a little
bit of an increase in QPF towards a half to two-thirds of an
inch, with 2 inch PWAT values contrasting with a rather
progressive system.
No changes to lows which look on track attm.
&&
.SHORT TERM /5 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Highlights...
* Warm and less humid for Saturday under mostly sunny skies.
Saturday: Surface low departs the near shore waters of southeastern
Massachusetts during the early morning hours. An isolated shower or
two isn`t out of the question along with areas of patchy fog through
mid Saturday morning. High pressure builds in from the west and
provides all of us a wonderful day under mostly clear skies. As we
are located on the eastern edge of the area of high pressure the
flow is out of the northwest and this ushers in a drier air mass
with dew points in the mid 50s. Winds are northwest 8 to 12 knots.
Afternoon temperatures are seasonable in the middle and upper 80s.
Saturday night: Quiet night with clear skies and light winds. Should
expect good radiational cooling with many locations outside of the
urban centers falling into the mid 50s, great night for sleeping
with the windows open. The urban centers will retain some heat,
resulting in lows 63 to 65 degrees.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Highlights:
* Warm, dry and tranquil weather Sunday with still comfortable
humidity levels.
* Very warm to hot weather with increasing humidity levels for most
of the upcoming workweek, potentially to oppressive levels mid to
late in the week.
* Best chance for showers and storms is with a cold front Tuesday,
though significant rain is not expected.
Details:
Sunday:
Tranquil and dry weather prevails as surface ridge remains in place
with shortwave ridge aloft. Good weather for outdoor plans Sunday,
and while it will be a touch more humid than Sat, still fairly
comfortable with dewpoints in the upper 50s to lower 60s and highs
in the mid 80s to perhaps a spot 90F reading away from the coast
(mid 70s to low 80s for the coasts). Low-amplitude shortwave trough
induces weak height falls and spreads increased cloudiness late-day
Sunday into overnight, but the cloud cover looks to be of the mid to
high variety and not likely to produce rains. Decreasing clouds
second half of the night but dewpoints rise into the mid to upper
60s. Fairly mild lows in the mid 60s to near 70.
Monday:
High pressure offshore brings SW flow to SNE. Very warm, humid but
also with some modest southwest breezes. Possible sea-breezes near
the coast as synoptic gradient at the moment looks on the weaker
side. Highs in the upper 80s to low 90s inland, lower 80s coastal
locales. Mostly clear to partly cloudy skies for the evening with
muggy lows mid-upper 60s to lower 70s.
Tuesday:
Tuesday still looks to feature the best chance for showers and
possible storms as a cool front moves eastward through New England.
Despite this, differences in deterministic and ensemble QPF both
placement and amounts are apparent as well as some minor variance in
frontal timing (at the moment, a frontal passage around the
afternoon to mid evening hours are favored but 12z ECMWF is a few
hours slower). Any rains will help and precipitable water values are
around 1.8 to 2 inches, but front seems too progressive to bring
significant wetting rains. Clearing by evening with highs in the
upper 80s to lower 90s inland, lower to mid 80s coastal areas. Lows
upper 60s to lower to mid 70s.
Wednesday through Late Week:
Ensemble means still indicate even warmer to hot weather and more
humid conditions are in store for Southern New England. While
deterministic global guidance is a few degrees higher, there are
strong probabilities for 850 mb temps at or greater than 20C. Latest
guidance indicates Thursday projects as the hottest and most humid
of the stretch; however Friday may also feature mid/upper 90s highs
as prior guidance has backed off on the timing of a sagging cold
front toward the weekend. Potential exists for heat headlines for at
least a part of this period but exact heat indices are still
unclear.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
02z TAF Update: no change from previous forecast thinking. Best
chance for a period of steady rains with MVFR conditions after
midnight over RI and southeast MA, then exiting 09z-12z. Earlier
discussion below.
=================================================================
Tonight: High confidence in trends, moderate on timing.
VFR initially begins to deteriorate approx. 03-05z as rain
expands NE. Rain however looks light enough for airports north
and west of I-95 that prevailing VFR looks more likely with
mainly dry runways. Best chance at MVFR/brief IFR
ceilings/vsby for PVD, Cape Cod and Islands after 06z. Rain
begins to taper off in the 08-12z timeframe. SW winds 6-10 kt
ease a bit thru midnight then to trend NW/N.
Saturday...High confidence.
VFR. NW winds 8-12 kt.
Saturday Night...High confidence.
VFR. NW winds 5-8 kt.
KBOS...High confidence in TAF.
KBDL...High confidence in TAF.
Outlook /Sunday through Wednesday/...
Sunday through Sunday Night: VFR.
Monday: Mainly VFR, with local MVFR possible. Breezy.
Monday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.
Tuesday: Mainly VFR, with areas MVFR possible. Slight chance
SHRA, isolated TSRA.
Tuesday Night through Wednesday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Winds and seas expected to remain below SCA thresholds through
Sunday. Rain showers move in this evening and exit on Saturday
morning. Can`t rule out a few thunderstorms for the waters
south of Block Island to Nantucket.
Outlook /Sunday through Wednesday/...
Sunday through Sunday Night: Winds less than 25 kt.
Monday through Monday Night: Winds less than 25 kt. Slight
chance of rain showers.
Tuesday: Winds less than 25 kt. Slight chance of rain showers,
isolated thunderstorms.
Tuesday Night through Wednesday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...Loconto/Gaucher
NEAR TERM...Nocera/Loconto/Gaucher
SHORT TERM...Gaucher
LONG TERM...Loconto
AVIATION...Nocera/Loconto/Gaucher
MARINE...Loconto/Gaucher
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
632 PM CDT Fri Jul 29 2022
.AVIATION...00Z TAFs
Isolated showers will affect the COT area for the next hour with
gusty winds and near MVFR vsbys possible with the stronger showers.
Convection is expected to diminish by 02Z. Gusty southeast winds
will linger through the evening hours over the Brush Country, then
become light over inland areas overnight. Patchy fog/MVFR vsbys
could occur over the inland coastal plains and brief MVFR ceilings
may develop over the Brush Country around daybreak. But chances
are remote and did not include in TAFs. Models depict air mass
will become drier on Saturday and the mid level ridge to the
north builds southward into the region. Do not expect isolated
convection with the sea breeze on Saturday. VFR conditions with
winds becoming gusty over the coastal plains in the afternoon with
the sea breeze.
&&
.PREV DISCUSSION... /Issued 330 PM CDT Fri Jul 29 2022/
SHORT TERM (Tonight through Saturday Night)...
Hot and humid summer time conditions continue into the weekend.
Broad mid level high pressure draped generally from TX to the FL
coast, will build slightly southwest across S TX tonight through
Saturday. This will bring drier mid level air across the area
leading to highs on Saturday being a degree or two warmer and lows
Saturday night a couple of degrees cooler. Low level moisture will
remain sufficient for the humidity to remain elevated through the
short term. The humidity combined with the hot temperatures Saturday
afternoon will result in heat indices of 105 to 109. A few locations
could briefly reach 110.
The drier airmass will lower the PWATs down to around 1.5 inches on
Saturday which is near normal for this time of year. Despite the
limited moisture and the high building across the area, most models
show isolated convection over the coastal waters Saturday with the
HRRR and RAP showing the isolated convection moving inland with the
sea breeze Saturday afternoon. Went with a 20 PoP across the
Victoria Crossroads where the moisture will be slightly deeper and
went with silent 5-10 PoPs across the remainder of the CWA for any
possible rogue showers.
There is a small window Saturday afternoon/evening across the Brush
Country/Rio Grande Plains when winds increase and just before the
humidity also increases, where elevated fire weather conditions will
be possible.
LONG TERM (Sunday through Friday)...
Concur with the deterministic GFS/ECMWF that an upper level inverted
trough of low pressure, and associated copious moisture, will move
westward across the region and contribute to at least isolated
convection Sunday/Monday. Expect the best chance for convection
activity over the CWA to occur Monday afternoon owing to the
combination of sea breeze convergence, moisture, and forcing
associated with the upper trough. The trough will move west of the
CWA and the upper ridge will begin to build Tuesday. Nevertheless,
additional isolated convection anticipated for Tuesday owing to
lingering moisture. Drying/subsidence should preclude convection
during the remainder of the period. Maximum Heat Index values
105- 109F Sunday/Monday. A slight increase in maximum temperatures
beginning Tuesday (owing to lower PWAT values/less moisture in
the vertical column) will combine with continued near surface
moisture to generate greater Heat Index values. Heat Advisory
conditions may occur Tuesday-Thursday over a significant portion
of the CWA. Greater wind speed magnitudes beginning Tuesday (owing
to slightly greater temperatures resulting in a greater MSLP
gradient) may combine with low minimum relative humidity values to
generate Elevated fire weather conditions over the Country/Rio
Grande Plains Tuesday-Friday.
MARINE...
A moderate onshore flow can be expected through this evening. The
flow will then become weak to moderate by Saturday morning and will
continue through Saturday night. Can not rule out an isolated shower
or two early Saturday morning. Isolated to scattered showers and
thunderstorms are possible by Saturday night. The combination of
an upper inverted trough/associated copious moisture, will
contribute to at least isolated convection Sunday/Monday. Addition
isolated convection early Tuesday owing to lingering moisture.
Anticipate moderate onshore flow during the period. Brief Small
Craft Advisory conditions may occur, especially Tuesday/Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 78 96 77 93 77 / 10 10 10 10 10
Victoria 76 98 76 96 76 / 10 20 0 10 10
Laredo 78 106 77 102 77 / 10 0 0 10 0
Alice 75 102 74 99 74 / 0 10 10 10 10
Rockport 83 94 82 94 81 / 10 10 10 10 10
Cotulla 79 107 77 105 77 / 10 10 0 10 0
Kingsville 79 101 76 95 76 / 0 10 10 10 10
Navy Corpus 83 96 82 90 81 / 10 10 10 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
TMT/89...AVIATION
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
814 PM EDT Fri Jul 29 2022
.SYNOPSIS...
A weak surface front will settle southward from Kentucky and the
Virginias into the western Carolinas late today and stall across the
region over the weekend. Abundant moisture will remain in place
across the area through the weekend and into early next week. The
front should dissipate by Tuesday, with high pressure over the
western Atlantic taking control for the rest of the week.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 810 pm EDT: Convection has mostly dissipated across the
western Carolinas and NE GA this evening. The weak frontal boundary
to our west has lead to showers and thunderstorm development across
eastern TN. This activity looks to weaken as it tracks eastward into
the western NC mtns. Have maintained chance PoPs along the NC/TN
border overnight to account for this activity. Went ahead and
decreased PoPs east of the mountains this evening into late tonight.
Otherwise, satellite imagery and RAP 500 mb heights continues to
show broad cyclonic flow in place over the eastern CONUS. Meanwhile,
the a weak cold front remains over over eastern KY and western WV
this evening. This boundary is expected to make steady progress
southward into the western Carolinas late this evening into the
overnight hours. Deeper moisture moving in with the frontal zone
could permit isolated to scattered showers to persist into the
overnight hours. Mins will run 5 or more degrees above climo, and
mountain valley fog/low stratus will be possible again if the debris
clouds thin sufficiently.
Precipitable water values will rise further during the day on
Saturday and the lingering boundary in the region should permit
coverage to be a bit higher during peak heating. That may be
especially true if the low-level flow acquires more of a S to SE
component as suggested in some models. Additional vorticity lobes in
the cyclonic flow aloft could yield a bit better upper support as
well. The hydro problem potential will rise with PWAT values nearing
2 inches and efficient rainfall likely in the warm cloud processes.
Still, no one area appears to have a high enough risk of flooding to
warrant any Flood Watches at this point. The severe threat could be
a bit less with more cloudiness and warm and moist profiles, but
isolated severe will remain possible in any areas receiving better
heating. Maxes should be near climatological values most areas on
Saturday afternoon.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 100 PM EDT Friday: Stalled frontal boundary will set up
shop from west to east across the CFWA Saturday night through
much of the day on Sunday. The better upper forcing should overlap
the boundary by the beginning of the short-term. With stout PWAT
values in place (2.00"+), deep warm cloud layer, skinny (-ish)
CAPE, and very weak MBE velocities, expect for convection that
develops along or in the vicinity of the boundary to potentially
train. This will uptick the overall flash flood threat, especially
in areas that have received appreciable rainfall the previous few
days leading up to the weekend. Numerous to widespread showers and
thunderstorms will be in store through the early part of next week
in this setup. With an enhancement of convective coverage during
peak heating due to the frontal boundary and upper divergence under
weak confluent flow, precipitation coverage should be able to thrive
in this setup and linger into the overnight hours Saturday and
Sunday. Thus, nocturnal chance to likely PoPs will remain in the
forecast. Few shortwaves will pass to the north during this time,
but a stronger shortwave trough will round out from the mid-MS
Valley Sunday through the OH Valley Sunday night and help reactivate
the frontal boundary into a warm front, which should help lift it
north of the CFWA by Monday. Placed under a warm sector regime and
factoring in the loss of upper forcing and surface convergence,
expect for more typical diurnally driven convection by peak heating
Monday. Temperatures will be near normal through the period due
to extensive cloud cover and higher than normal PoPs.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 230 PM EDT Friday: Lingering upper troughiness will remain
in place across the area through the early part of next week,
which should continue to allow for above normal PoPs and near
normal temperatures. The synoptic pattern will begin to shift
as the upper ridge over the western Atlantic retrogrades over
the southeastern CONUS behind the departing upper trough to the
north. Typical mid-Summer pattern should settle over the region by
the middle part of next week with diurnally driven convection and
slightly above normal temperatures. Localized pulse severe storms
and flash flooding will still impact the region, but these threats
will be much lower compared to the short-term forecast.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: SHRA and TSRA have mostly dissipated across
the western Carolinas this evening. Have a scattered convection
tracking across eastern TN that is associated with a weak frontal
boundary. This activity should weaken as it tracks into the western
NC mtns. Added VCSH at KAVL to account for this activity. Mountain
valley fog and low stratus are expected again overnight into
daybreak Saturday. Low stratus and fog are possible east of the
mountains for areas that saw heavy rainfall earlier today. However,
confidence was too low to mention in the 00Z TAF forecast period.
Winds will be light and variable overnight into early Saturday
morning. The weak frontal boundary will continue pushing east across
the western Carolinas overnight into Saturday morning before
stalling across the SE CWA. This FROPA will allow for scattered SHRA
and TSRA chances to return Saturday afternoon and evening, so have
PROB30s at all TAF sites. Expect lighter wind speeds on Saturday
compared to the last few days.
Outlook: Diurnal scattered to numerous showers and thunderstorms are
expected this weekend and into early next week. Fog and low stratus
may develop each morning in the mtn valleys and where appreciable
rain has fallen the previous evening.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...CAC/HG
NEAR TERM...AP/HG
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...AP
Area Forecast Discussion
National Weather Service New York NY
1200 AM EDT Sat Jul 30 2022
.SYNOPSIS...
A cold front, with a wave of low, tracks through the region
overnight. A weak surface trough passes through on Saturday
while high pressure begins to build in from the Midwest. The
high moves overhead on Sunday and slides offshore by midweek. A
few weak frontal systems will impact the region late Monday
through Tuesday, followed by building high pressure toward the
end of the week. A cold front approaches on Friday.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Made minor updates to the forecast for the overnight, removing
the chance of thunder over the ocean waters.
Aloft, an upper- level low within a 500-mb trough is located
over southeast Canada, with a relatively potent jet rounding the
base of the low.
A weak area of low pressure develops along the approaching front
and tracks just south of the region tonight into early Saturday
morning. With the trough to our west, and the area falling under
the RR quadrant of a potent 140 kt jet streak over northern New
England, clouds and rain with the wave should extend farther
north through the area. The wet weather comes to an end from
west to east after 06z, with everyone dry by 12z at the latest.
Patchy fog may develop in spots close to daybreak.
Storm total rainfall is expected to be around a quarter of an
inch for much of the region, though higher amounts are likely
where the corridor of heaviest rain falls.
Temperatures overnight range from the mid 60s to low 70s.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
The upper level trough axis remains over the area early in the
day, with heights beginning to rise as the trough lifts north
and east. Cyclonic flow associated with the trough may allow for
a few mid- level clouds to develop in the afternoon, though
skies should be predominantly sunny through the day.
Temperatures remain warm behind the frontal passage, with most
areas topping out in the mid-to-upper 80s. Drier air advects in,
however, with a northwest flow setting up as surface high
pressure begins to build in from the Midwest. Forecast dew pts
fall into the 50s, helping make it feel more comfortable
outside.
Ideal radiational cooling conditions set up Saturday night,
with light winds and clear skies. Leaned toward the cooler MOS
guidance for lows. Cooler spots in the interior and LI Pine
Barrens likely bottom out in the upper 50s, with mid 60s to low
70s elsewhere.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Ensembles depict zonal flow followed by an amplifying longwave
ridge over the northeast through much of the period, with
building heights aloft from midweek through the end of next
week. The area will likely experience another round of excessive
heat next week as a result.
In terms of sensible weather, high pressure remains overhead on
Sunday giving way to a warm front that will approach from the
south as its parent surface low heads through upstate NY on
Monday. Shower chances will increase on Monday afternoon as the
front approaches, but at this point, precip looks to be light
with very limited instability. By Tuesday, the area becomes warm
sectored as southerly flow increases, and have added thunder
chances for the afternoon as instability increases (500-1000J/kg
per GFS soundings.) ahead of a weak cold front and prefrontal
trough. Precip chances ramp down the frontal system moves
offshore by Tuesday night. CSU ML severe forecasts showing the
5-15% chance for severe across much of the eastern seaboard for
Tuesday.
High pressure then follows for Wednesday and moves offshore by the
end of the week. This will allow deep southwest flow to begin
bringing in a more warm and humid airmass for Wednesday. 850mb
temperatures begin to rise to the low 20s into Friday, as dewpoints
are progged to reach the low 70s. Have adjusted high temperatures up
toward the NBM 50th percentile, which is above the NBM deterministic
MaxTs. The 50th percentile MaxT from NBM performed quite well during
the previous heat event across the local area. Heat indices are
expected in the upper 90s to low 100s for much of the area on
Thursday, and possibly into Friday. A cold front approaches for
Friday, and depending on the timing, Friday may be a few degrees
warmer than Thursday should the front sweep through late in the
day.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
A frontal wave passes to the south and east overnight, dragging
a cold front through the area. High pressure will then build in
slowly from the west on Saturday.
Mainly VFR overnight, but occasionally MVFR in some heavier
showers. Much of the showers will be east of the area by
daybreak with the possible exception of the terminals east of
NYC. Few-Sct Cu around 5-7kft Saturday afternoon.
W/SW winds become light and variable over the next few hours as
low pressure approaches from the SW and a cold front approaches
from the NW. Winds shift to the N-NW late at less than 10 kt,
then become NW 10-15kt on Saturday, with occasional higher gusts
in the afternoon, gradually backing to the west.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of showers this evening (00z to 07z) may be off by an
hour or two.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
.Saturday Night through Sunday...VFR.
.Monday and Tuesday...Mainly VFR. Slight chance of a shower or
thunderstorm, mainly in the afternoon and evening.
.Wednesday...VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Adjusted winds, gusts, and ocean seas for current conditions and
trends through the overnight. Also, removed the thunderstorms
over the ocean waters as any convective activity will remain
well to the south.
Winds and seas should remain below SCA levels on all waters
into early next week.
&&
.HYDROLOGY...
No hydrologic impacts are expected through late next week.
&&
.TIDES/COASTAL FLOODING...
There is moderate rip current risk on both Saturday and Sunday
from a combination of 2-3 ft S wind waves and 2-3 ft SE swells.
The rip risk may lessen by Sunday afternoon.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DBR/DR
NEAR TERM...DBR/DR/MET
SHORT TERM...DR
LONG TERM...DBR
AVIATION...DW
MARINE...DBR/DR/MET
HYDROLOGY...DBR/DR
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Pueblo CO
352 PM MDT Fri Jul 29 2022
.SHORT TERM...(This evening through Saturday)
Issued at 232 PM MDT Fri Jul 29 2022
Key Messages:
1) Scattered to numerous showers and thunderstorms through the
evening with best coverage across the Southern Tier.
2) Warmer tomorrow with best coverage of afternoon storms over
and near the higher terrain.
Current water vapor imagery and upper air analysis is indicating
modest westerly flow aloft across the region, with satellite data
indicating PWATS running 120 to 150 percent of normal across the
Central Rockies. Water vapor imagery is also indicating one embedded
short wave translating through the Northern Rockies, with another
embedded wave translating across northern New Mexico. SPC meso-
analysis has MUCape of 1000-2000 j/kg across the higher terrain,
greatest across the Northern mountains, with MUCape of 500-1000
j/kg across the southeast plains.
Models continue to indicate flow aloft becoming more north to
northwest through the day tomorrow, though remaining weak, as
the northern Rockies wave continues to translate south and east
into the High Plains and upper level ridging continues to build
into the Great Basin.
For the rest of tonight, should see showers and storms continuing
to develop and move east southeast across the region, with the best
coverage of storms remaining across the southern tier and out across
the far southeast plains. These storms could continue into the late
evening and into the overnight hours, especially across the far
southeast plains, as the northern New Mexico wave continues to
translate east overnight. Cloud cover and low lapse rates across
the region has limited storm strength today, especially across the
southern tier, however, with more solar heating, storms across the
northern and central mts and moving into the Teller County have been
more feisty, with very heavy rainfall being observed with these
stronger storms. At any rate, the latest runs (19Z and 20Z) of HRRR
indicates these stronger storms will diminish in strength as they
continue to move southeast across the adjacent plains. Further east,
with storms continuing to develop across the far southeast plains, will
keep the Flood Watch out for Bent, Prowers and Baca Counties, where
saturated soils could lead to flash flooding. With the ample moisture in
place and weak upslope flow across the plains, will see some clouds
persisting across the area into the overnight hours, with stratus
possible again along the lower eastern slopes.
On Saturday, should see clearing skies through the early morning,
with showers and storms developing over and near the higher terrain
once again through the late morning and afternoon. Best coverage of
storms shifts slightly west across the ContDvd, with all storms being
slow moving and capable of producing heavy rainfall, leading to
another day of possible flash flooding. However, with no evident short
wave to help trigger storms, there is no clear cut place for any flash
flood highlights at this time. Further east across the plains, models
indicate low level moisture in place, leading to Sbcape of 1000-1500
j/kg into the afternoon. However, model soundings indicating a healthy
cap in place. Temperatures do warm back into the 80s across the plains,
with 60s and 70s across the higher terrain.
.LONG TERM...(Saturday night through Friday)
Issued at 232 PM MDT Fri Jul 29 2022
Key messages:
1) Warmer and generally drier weather for the week.
.Sunday through Tuesday...Upper ridge over the Pacific Northwest
continues to drift to the east southeast passing over Colorado on
Monday. Middle and upper level monsoon moisture will continue moving
through the ridge for diurnal convection over and near the
mountains. The best chances for thunderstorms will mostly be over
the eastern San Juan Mountains. Precipitable waters over the
mountains remain roughly 0.5 to 0.75 inches, which can result in
storms producing locally heavy downpours. Models and ensembles have
precipitation chances decrease towards the east with residual
moisture remaining on the plains. Suspect that storms which move off
of the mountains and into the I25 corridor and eastern plains will
become higher based with less rainfall and gusty winds. Hot weather
returns to the plains with highs in the 90s to around 100.
.Wednesday through Friday...Ensemble means have the upper ridge
drift to the east with increase southerly flow aloft, which would
increase the mid and upper level monsoon moisture over the region.
Models hint at a weak front passing over the plains on Wednesday.
The upslope behind this front could briefly increase low level
moisture on the plains. NBM PoPs increase over the mountains and
nearby plains with the increase in moisture. The latest GFS and EC
show a fairly sharp trough passing across the northern Rockies,
which could enhance convection. Latest EPS and GEFS show hints of
this feature, but it is not a sharp as in the operational models.
Ensembles suggest there is much variability in the strength and
timing of this trough. Hot weather continues on the plains with
highs generally in the 90s. --PGW--
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 232 PM MDT Fri Jul 29 2022
Moist upslope flow and monsoonal moisture in place across the
region will keep mainly VFR cloud cover in place at COS and PUB
through the evening, as storms develop across the higher terrain
and try to move east into a more stable environment across the
adjacent plains. Storms will still be possible at terminals
from the late afternoon and evening hours, with MFVR and brief
IFR conditions possible with heavy rainfall and gusty outflow
winds the main threats, if storms can develop/move over the
terminals. Convection wanes through the evening, and with the
ample moisture in place, could see MVFR stratus develop once
again at the terminals overnight. VFR conditions are expected
through the rest of the period, with storms remaining over
and near the higher terrain.
At ALS, scattered showers and storms expected at the terminals
through the afternoon and evening hours, bringing occasional
mvfr and patchy ifr conditions. Showers could linger into the
late evening hours, with MVFR stratus likely developing once
again at the terminal overnight. VFR conditions are expected
across through the rest of the period, with more isolated
storms possible Saturday afternoon.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 PM MDT this evening for COZ094-097>099.
&&
$$
SHORT TERM...MW
LONG TERM...PGW
AVIATION...MW
Area Forecast Discussion
National Weather Service Blacksburg VA
944 PM EDT Fri Jul 29 2022
.SYNOPSIS...
A frontal boundary will slide south into the Carolinas Saturday,
then lift back north as a warm front Sunday into early next
week. This will keep our area in an unsettled weather pattern.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 940 PM EDT Friday...
...Warm and muggy night...
Convection is waning and having a hard time arriving along the
cold front. Have cancelled the Flood Watch a little early. It
will be a warm and muggy night with some fog around where we can
get some clearing. It will take all night for the front to move
through, and until tomorrow when some drier air finally arrives.
As of 650 AM EDT Friday...
Remainder of Severe Watch cancelled, Flood Watch still in
effect...
Weak storms are continuing to move east out of the area. Still
some convection south of Danville into parts of northern NC,
but besides heavy rainfall and lightning the storms are not a
threat. To the west, have kept the Flood Watch up as a cold
front nears locations which have seen 1-4+" in the last 48
hours, mainly along the WV/VA border and a county or so south.
Showers and storms currently forming in central WV will try and
reach the Flood Watch area, but many CAMs show them diminishing
as they run into the terrain and also a more stable and cooler
air mass. This will also coincide with the loss of heating.
However, the threat of training cells increases as the boundary
nears, and it would not take much to cause flooding problems.
So will keep a close eye on this.
Expect fog to form overnight into the early morning hours with
dry air lagging behind the actual FROPA.
As of 515 PM EDT Friday...
Trimming back Severe Watch...
Convection has been having trouble becoming severe or even
strong, even in areas that saw plenty of sun today. The best
instability is to our south while the better speed shear at
500mb and 300mb is to our north. Westerly winds at the surface
are also not helping the situation as a surface trough shifts
into eastern VA. Have dropped part of the watch that we do not
expect to see redevelopment in, but we may be dropping the
remainder of the Severe Watch and perhaps the Flood Watch in
the next 1-3 hours. Dropping the Flood Watch will depend on what
develops along a cold front which is still to our northwest.
As of 130 PM EDT Friday...
Currently watching the progression of a cold front to the west,
slowly drifting southeast through this evening. Ahead of this
front, have seen quite a bit of clearing and in response to
this, strong destabilization is occuring across much of
Virginia and North Carolina. Expecting wider coverage of storms
within the next hour or two as better forcing works eastward,
with activity beginning over the mountains and then eventually
spreading east into the Piedmont of Virginia and North Carolina.
Storm mode will likely be multicell/line segments with damaging
winds being the main threat.
Flooding remains a threat this afternoon and evening as well
owing to a very saturated airmass in place. RAP analysis has
PWAT values of around 2 inches across the area which will result
in very efficient, heavy rainfall rates. The biggest concern for
flooding will be for southeast West Virginia and southwest
Virginia where saturation has occured from multiple days of
rainfall through the week. Due to low flash flood guidance and
the potential for very heavy rainfall rates impacting these
areas again today it will not take much rainfall to cause
flooding issues, so opted for a Flood Watch until 10 PM EDT for
southeast WV and far southwest Virginia.
Front will progress through the area tonight and rain should
eventually taper off with the exception being some lingering
showers for the far western mountains. The front eventually
stalls over the Carolinas and most rainfall on Saturday will be
confined along and south of the NC/VA border.
Temperatures this afternoon will feature 90s across the eastern
areas, with 70s and 80s elsewhere. Guidance has been running a
bit low on temperatures so have bumped up highs slightly this
afternoon. Temperatures on Saturday will be several degrees
cooler, featuring highs in the 70s and 80s across the entire
area.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
As of 200 PM EDT Friday...
Lifting front Sunday returns rain...
A front will sag southward late Saturday, pushing the currently
stalled front also south of its position. This will help keep
any rain chances near or south of the VA/NC border Saturday
night. Into Sunday and part of Monday, the front will slowly
lift northward, transiting the CWA at a leisurely pace, but
again returning heavy showers and storms to the forecast area.
Of particular concern are the regions of far southwest VA,
particularly Tazewell and Smyth counties, and southeast WV,
where almost daily rain has saturated the ground for the past
week. Flash flood guidance values will be exceptionally low, so
it won`t take much rain to tip the scales and create flooding
issues in these areas. When considering the high rain rates
expected with these showers, a close eye will be kept on
hydrology concerns Sunday and Monday.
Since we will be on the cool side of a frontal boundary and
sitting under clouds and rain showers, temperatures have been
held on the cool side, with highs only in the 70s and low 80s
for this forecast period.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 310 AM EDT Friday...
Warming Temps And Diurnal Rain Chances...L
After the front exits to our north Monday, we will return to a
more typical diurnal summer pattern as a subtropical ridge edges
north and into the Mid-Atlantic. Some chance PoPs will fit in
each afternoon as heating destabilizes the atmosphere. Model
guidance doesn`t exhibit a consistent time frame for the next
organized system or front to pass through next week.
Temperatures will be around normal for early August in the
extended time frame.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
As of 635 PM EDT Friday...
Showers and storms are diminishing and moving southeast away
from KDAN and KLYH. A cold front will move through tonight, and
may still bring a few SHRA/TSRA to KBLF and perhaps KLWB through
02Z. Thereafter the rain threat should drop everywhere.
Cigs and vsbys will drop to sub-VFR tonight as drier air takes
its time filtering in. Fog may become more an issue at
LWB/BCB/LYH once we begin to clear.
Fog burns off an hour or two after sunrise and most locations
should go back to VFR with perhaps some lingering mixed MVFR
conditions in the mountains.
Forecast confidence is average.
.Extended Aviation Discussion...
The front will meander and linger through Saturday with highest
chances for storms in the afternoon hours Saturday south of the
VA/NC border. The abundant moisture and daily precipitation
will result in areas of dense late night/early morning fog/low
clouds with MVFR or lower conditions.
The front to our south lifts back north as warm front Sunday
into early next week, keeping the rain threat around with sub-
VFR likely at times. Fog also possible in the late night/early
morning time frame.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...BMG
NEAR TERM...BMG/SH
SHORT TERM...VFJ
LONG TERM...VFJ
AVIATION...BMG/WP