Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/06/22
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
921 PM CDT Mon Sep 5 2022
.UPDATE...
Issued at 919 PM CDT Mon Sep 5 2022
No updated planned with the evening update.
UPDATE Issued at 620 PM CDT Mon Sep 5 2022
No significant changes to the early evening forecast. Cloudless
sky but smoke remains aloft over the forecast area with some near
surface smoke over western ND. A weak cold front will move through
the area tonight through Tuesday. This should help clear out the
near surface smoke in the west, at least temporarily.
Updated text products will be transmitted shortly.
&&
.SHORT TERM...(This Evening through Tuesday Night)
Issued at 239 PM CDT Mon Sep 5 2022
Highlights for the short term period include well above normal
temperatures, near critical fire weather conditions in the west, and
smoke aloft.
An upper level ridge axis is rebounding over eastern Montana and the
western Dakotas early this afternoon behind a departing shortwave. A
surface trough is currently analyzed along the Highway 83 corridor
and is drifting east. Winds along the surface trough are light, but
southerly winds are sustained near 20 mph ahead of the trough.
Behind the surface trough, winds have turned westerly around 10 to
15 mph. Afternoon temperatures are already in the 90s across western
North Dakota, with humidity below 20 percent. Winds are expected to
remain under 20 mph across western North Dakota through the rest of
the day, but the very low RH in the presence of the westerly breeze
will result in near critical fire weather conditions. Much lighter
winds along the surface trough and higher dewpoints to the east will
keep the fire weather concerns limited to western North Dakota.
The Northern Plains will sit at the northeast corner of the strong
dome of high pressure through Tuesday as a progressive Canadian
shortwave forces an enhanced zonal flow along the international
border. This pattern will continue to advect smoke aloft from
western US wildfires over the region. The 12 UTC HRRR implies a
moderate thickness to the smoke, which could impact the low and high
temperature forecast by a few degrees. However, light winds and no
clouds would otherwise promote strong cooling and heating, so the
affects of smoke on temperature may be canceled out in the forecast.
Highs on Tuesday are expected to range from the lower 80s far north
to mid 90s far southwest and south central. Despite another day of
low RH, especially in the southwest, lights winds will preclude any
fire weather concerns.
.LONG TERM...(Wednesday through Monday)
Issued at 239 PM CDT Mon Sep 5 2022
Well above normal temperatures will quickly transition to below
normal with the passage of a cold front now set to arrive on
Thursday.
A transient ridge approaching the Canadian prairie provinces and
lining up with the peak of the CONUS dome of high pressure will
allow the thermal ridge to strengthen over the Northern High Plains
on Wednesday. This should result in widespread highs in the upper
80s to upper 90s, but smoke aloft could once again be a factor in
the temperature forecast. South-southeast surface flow between
downstream high pressure and upstream low pressure may be under-
represented in NBM guidance, as was the case in a similar regime
yesterday. But at this time, little to no overlap of sustained winds
around 20 mph or greater and RH 20 percent or lower is expected,
with the driest conditions once again kept in far southwest North
Dakota.
Recent deterministic and ensemble guidance has greatly sped up the
passage of a cold front attendant to a deepening trough ejecting off
the Canadian Rockies. The consensus time of arrival in northwest
North Dakota implied by NBM surface fields is now early Thursday
morning, with the front clearing the forecast area by the evening.
This forecast change is reflected in the entire NBM maximum
temperature distribution in the northwest shifting 10 degrees cooler
since this time yesterday! Ensemble cluster analysis also shows
strong support for the sped up frontal passage, with near unanimous
consensus from the perhaps under-dispersive ECMWF ensemble (the 12
UTC deterministic ECMWF is even faster though). Locations along and
ahead of the front at midday, which could include much of south
central and eastern North Dakota, are still likely to see highs in
the mid 80s to mid 90s, with some possible assistance from
compressional heating. The boundary layer wind field and cold air
advection associated with the front do not look as strong as was
indicated by previous model suites, but the timing of the front now
better coincides with steep low level lapse rates. While wind speeds
may remain below advisory criteria and critical fire weather
thresholds, the potential for a sharp wind shift moving through an
antecedently hot and dry air mass could cause fire weather to be a
concern on Thursday.
Deterministic guidance suggests chances for rain should mostly be
post-frontal, coinciding with stronger height falls arriving later
on Thursday. CAPE looks very minimal to non-existent, but strong
shear and modest lapse rates could promote localized strong wind
gusts with any shower or storm, though the probability of lightning
is not high enough to mention in the forecast at this time. The full
effects of the colder air mass will be felt on Friday when the NBM
projects highs mainly in the 60s. The cyclonic flow regime on Friday
could be conducive to diurnal convective shower activity, and a
secondary vort max rounding the base of the trough could provide
supplemental forcing. The low temperature forecast for Friday
night/Saturday morning bears watching, with the NBM already
advertising widespread lower to mid 40s and pockets of upper 30s.
Cluster analysis shows strong support for regional surface high
pressure, but a mixed signal on cloud potential, owing to
uncertainty on the progression of the upper trough, which is also
keeping low chances for rain in the forecast through Friday night.
Ensemble spread begins to widen more greatly into early next week.
There is a general theme for a rebounding of the western CONUS ridge
over this time period, with ECMWF ensemble mean height fields more
amplified than their GEFS counterparts. Aside from the potential for
post frontal showers late Thursday through Friday, the chance of
measurable rain through the long term period is near zero.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 919 PM CDT Mon Sep 5 2022
VFR conditions are expected through the 00Z TAF period. Possible
reductions in vsby due to smoke west tonight but predictability
too low to mention in KDIK or KXWA TAF.
A westerly wind at KXWA and KDIK with a southerly wind at the
remaining TAF sites to begin the TAF period. Winds diminishing
this evening. A cold front will move east across the remaining TAF
sites tonight through Tuesday morning, with All TAFS shifting
westerly then northerly behind the cold front. Wind speeds light
tonight and generally 15 mph or less Tuesday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...TWH
SHORT TERM...Hollan
LONG TERM...Hollan
AVIATION...TWH
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
624 PM CDT Mon Sep 5 2022
...New AVIATION...
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 242 PM CDT Mon Sep 5 2022
Ample tropical moisture will continue to remain in place through
the short term period. This mornings sounding showed PWATs of 2.20
inches with forecast PWATs remaining between 2 and 2.25 through
Tuesday, especially across the lower Valley. This excess moisture
along with a slowly sagging weak boundary will continue to lead to
rain and some thunderstorm chances across Deep South Texas into
tomorrow. So far today, most of the heavy activity has remained
offshore, but showers and thunderstorms are still expected across
the region. WPC maintains the slight risk of excessive rainfall
for Cameron, Willacy and southern Hidalgo today, with a marginal
risk for much of Deep South Texas on Tuesday.
Temperatures will continue to remain below normal through the
period due to the excess cloud cover and continuing rain chances.
Temperatures on Tuesday will be a touch warmer than today and top
out in the upper 80s to low 90s. Anywhere that sees sunshine could
experience temperatures a bit higher than currently forecasted.
Overnight lows will remain generally in the mid 70s both tonight
and tomorrow night. Winds will also remain fairly light, though
brief gusty winds are possible with any thunderstorm activity.
&&
.LONG TERM...
(Wednesday through next Monday)
Issued at 242 PM CDT Mon Sep 5 2022
Unsettled weather will stick around through mid week before drier
air moves in, tapering rain chances off through late week. Temps
will start off a few degrees below normal on Wednesday, gradually
warming, but will stay near or just shy of seasonal averages.
Deep South Texas and the Rio Grande Valley will remain partially
under the influence of a positively-tilted mid to upper level
trough that will quickly become a cutoff low over Louisiana,
spinning over the region into the weekend. The best chances for
rain in the long term will be on Wednesday before precipitable
water values drop below two inches and a shortwave rounds the
base of the trough.
As drier air filters in (especially in the mid to upper levels
with the northerly flow as we sit on the southwestern side of the
mid-level low), rain chances will taper off through the rest of
the work week, but just enough moisture will remain to support
daily sea-breezes, though coverage will be isolated, leaving most
areas dry. The surface pressure gradient will remain very weak,
supporting lighter winds that will likely be dominated by diurnal
processes (easterly wind shifts with the sea breeze).
Heading into the weekend, some difference will arise among the
deterministic model guidance, but not too much. Both global models
suggest clearing skies and lowering rain chances, even as another
mid-level short wave trough dives into the Mississippi Valley.
For now, used the NBM which brings isolated PoPs, at best, with
the sea breeze each day through the weekend.
Under this pattern, temperatures will remain below average
initially with Wednesday being the coolest day (temperatures near
90 to the lower 90s across the RGV) before temperatures stabilize
and recover to near normal thereafter.
&&
.AVIATION...
(00Z TAFS)
Issued at 614 PM CDT Mon Sep 5 2022
Light rain from Mexico should affect MFE through the next few
hours, while BRO and HRL remain dry. The HRRR model suggests that
all aerodromes will encounter additional convection tomorrow, so
a TEMPO for it has been included in the current issuance of TAFs.
Overall, VFR should prevail through a majority of the next 24
hours.
&&
.MARINE...
Issued at 242 PM CDT Mon Sep 5 2022
Now through Tuesday Night...Shower and thunderstorm activity will
continue through the period that could lead to localized areas of
elevated winds and seas along with downpours and occasional to
frequent lightning. Otherwise, expect generally light wind and
seas running around 2 to 3 feet.
Wednesday through Saturday Night...A mid-level trough will sag
south over the Lower Mississippi Valley and into the North Gulf
late in the week. A mid-level low will cut off over Louisiana and
a surface stationary front will lie over the North Gulf Coast. The
surface pressure gradient will remain weak. Thus, light to
moderate variable direction winds and low to moderate seas will
prevail through the long term. Due to the aforementioned
destabilizing features, showers and thunderstorms will arise from
time to time. Another mid-level trough will dive into the Lower
Mississippi Valley late in the weekend, supporting persistent
unsettled Gulf weather, absent small craft advisory conditions.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 77 90 77 90 / 60 70 50 70
HARLINGEN 75 88 74 89 / 60 70 30 50
MCALLEN 75 90 75 92 / 60 70 30 50
RIO GRANDE CITY 75 89 75 91 / 60 70 30 40
SOUTH PADRE ISLAND 79 87 79 86 / 60 60 40 60
BAYVIEW/PORT ISABEL 77 88 76 88 / 60 60 40 60
&&
.BRO WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Area Forecast Discussion
National Weather Service Cheyenne WY
535 PM MDT Mon Sep 5 2022
.SHORT TERM...(This evening through Thursday)
Issued at 230 PM MDT Mon Sep 5 2022
Key Impact Messages:
1) Well above to record breaking temperatures likely to continue
into Thursday.
2) Patchy areas of smoke and haze from wildfires across southern
Idaho and northern California expected to increase across the
region on Tuesday.
3) Critical fire weather conditions may be possible Thursday
afternoon, especially across Carbon and Albany counties.
Weather Details: Forecast remains on track as we will continue to
sit under a large area of high pressure with 700mb temperatures
hovering between 19-20C. The expanding thermal ridge moves into
the region Tuesday and strengthens on Wednesday. Numerous record
high temperatures could be broken over the next several days, see
climate section below. Temperatures are expected to be in the
96-101 range along and east of the I-25 corridor and into the
100-105 range across the NE Panhandle over the next three days.
Large wildfires across southern Idaho and northern California may
bring some areas of patchy smoke and haze into the region this
afternoon and into tomorrow. HRRR smoke model has been consistent
in pushing a concentrated area of thick smoke across Carbon county
by morning and moving it east through Laramie and into western
Laramie county by late morning. This area of smoke my impact
temperatures through the morning and bring some reduced visibility
and maybe a window of poor air quality. HRRR diminishes this smoke
by noon but another surge of smoke and haze expected to infiltrate
into northern Wyoming.
.LONG TERM...(Friday through next Monday)
Issued at 230 PM MDT Mon Sep 5 2022
Latest model runs have remained consistent with a strong cold front
moving through Thursday night into Friday, drastically dropping
temperatures 15 to 20+ degrees. Forecast high temperatures Friday
are upper 60s to low 70s in southeast Wyoming and 70s in the
Nebraska panhandle. Scattered chances of showers mainly along and
east of the Laramie Range through Friday, tapering off to the
southeast Saturday morning. Saturday looks to be the coolest day in
the upcoming long term forecast period with morning low temperatures
sitting in the lower 40s and afternoon high temperatures in the 60s
to 70s. As this frontal passage is still 6 to 7 days out, there is
still low confidence in how this low pressure will evolve.
Following the potential nice, fall temperatures, southeast Wyoming
and the Nebraska panhandle dries out and warms up to the 80s again
by Monday.
&&
.AVIATION...(For the 00Z TAFS through Tuesday evening)
Issued at 535 PM MDT Mon Sep 5 2022
Strong upper level high pressure will continue to dominate the
weather pattern early this week. Generally light winds and
limited, if any, cloud cover is expected to continue. Some
smoke from the wild fires to the north may spread into the area
from time to time, but no limitations in VIS expected at this
time.
HAZARDS/WEATHER TRENDS: VFR condition expected tonight and Tuesday.
Winds will become light and variable tonight with surface winds
shifting into the east or southeast across the high plains terminals
by 18z Tuesday.
&&
.FIRE WEATHER...
Issued at 230 PM MDT Mon Sep 5 2022
Well above to record high temperatures expected to
continue through Thursday with critical minimum RH values between
10 to 15 percent with single digits RH values across Carbon
County. Under the influence of a strong high pressure system,
winds will be variable with erratic gusts during the afternoon
hours. Wind and wind gusts should remain below criteria so no fire
highlights are expected through Wednesday. An approaching strong
cold front on Thursday will increase the winds significantly
across Carbon county and parts of Albany county. Critical fire
weather conditions may develop across these areas Thursday
afternoon.
&&
.CLIMATE...(Tuesday through Thursday)
Issued at 230 PM MDT Mon Sep 5 2022
Tue 9/6: City Forecast High Temp Record High Temp
Cheyenne 96 deg F 91 deg F (2020)
Scottsbluff 103 deg F 102 deg F (2013)
Chadron 104 deg F 102 deg F (1998)
Wed 9/7: City Forecast High Temp Record High Temp
Cheyenne 97 deg F 90 deg F (1959)
Scottsbluff 103 deg F 101 deg F (1908)
Chadron 105 deg F 99 deg F (1931)
Thu 9/8: City Forecast High Temp Record High Temp
Cheyenne 94 deg F 91 deg F (1979)
Scottsbluff 102 deg F 98 deg F (2013)
Chadron 99 deg F 103 deg F (1959)
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...AW
LONG TERM...LK
AVIATION...LK
FIRE WEATHER...AW
CLIMATE...LK
Area Forecast Discussion
National Weather Service Grand Forks ND
1055 PM CDT Mon Sep 5 2022
.UPDATE...
Issued at 1054 PM CDT Mon Sep 5 2022
No change in thoughts to prior update.
UPDATE Issued at 702 PM CDT Mon Sep 5 2022
Breezy southerly winds are dwindling, and should dip to around 10
mph tonight. Skies are expected to remain clear sans elevated
smoke which should stay aloft through tonight. Efficient
radiational cooling is expected tonight, which may allow for some
shallow, patchy radiational fog to form near an incoming sfc warm
front from central ND where winds have the best chance of being
calm. Expected timing of the front brings this fog potential from
Devils Lake basin south to the Sheyenne and James River Valleys.
However, given how dry the lowest levels are, impacts are
generally not expected given its patchy and shallow nature. Thus,
will opt to leave out of the forecast for now.
There is some possibility elevated smoke could mix to the surface
tomorrow west of the front as currently noted in eastern MT,
however impacts from visibility and air quality reductions are
not expected.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 311 PM CDT Mon Sep 5 2022
Impacts are not expected this afternoon or evening, with mostly
sunny skies and temperatures generally in the middle 70s to low 80s.
South to southeast winds prevail at 20 to 25 mph, with gusts
reported as high as 40 mph, especially within the Red River Valley.
Outside the Valley, we are seeing gusts range from 30 to 35 mph.
Hazy skies are possible through the remainder of the afternoon and
evening due to mid and upper level smoke advecting into the area.
The HRRR vertically integrated smoke product keeps this above the
boundary layer through at least the overnight hours; however, there
could be a minor impact on temperatures this afternoon, as we are
slightly below NBM forecast guidance thus far. The potential for
smoke at the surface will be minimal.
Low temperatures tonight are expected to be a bit warmer than last
night, with lower 50s along the International Border and near 60
degrees in the southern Red River Valley. Heading into Tuesday, look
for highs in the 80s across the region, along with breezy northwest
winds for areas west of the Red River.
.LONG TERM...(Wednesday through Monday)
Issued at 311 PM CDT Mon Sep 5 2022
Not much in the forecast for impacts in the long term period. Mid-
week will be quieter, with the possibility for some warmer
temperatures on Thursday. Spread in the ensembles is high, so not
too confident on how warm we could be for high temperatures.
High pressure in the mid and upper levels will break down at the end
of this week, allowing a trough to briefly pass through the area.
The attendant cold front will bring in cooler temperatures, but the
possibility for precipitation remains up in the air. Ensembles have
not decided on a solution for where the most likely area for QPF is
yet, so confidence is low on any precipitation forecasting in the
area for Friday and Saturday. As of now though, any precipitation
received looks to be minimal.
The remainder of the weekend and into next work week looks to be
more seasonal, with highs in the 70s across eastern North Dakota and
west central Minnesota. After the trough exits, another period of
quiet weather will begin.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1054 PM CDT Mon Sep 5 2022
No change in thoughts to 06Z TAFS from 00Z TAFS.
VFR conditions are expected throughout the TAF period. Southerly
winds will shift westerly to northerly behind an incoming front
from central ND, although generally expected to remain under 12 kt
through tomorrow afternoon. Elevated smoke will linger across much
of the region throughout the period, and generally remains above
6 kft.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...CJ
SHORT TERM...Lynch
LONG TERM...AK
AVIATION...CJ
Area Forecast Discussion
National Weather Service Goodland KS
550 PM MDT Mon Sep 5 2022
.SHORT TERM...(This evening through Thursday Morning)
Issued at 136 PM MDT Mon Sep 5 2022
High pressure continues to dominate the High Plains as virtually no
cloud cover is present across the area. Surface troughing is
resulting in a tighter pressure gradient across west
Kansas/east Colorado resulting in occasional gusts approaching 25
knots; the weak wind field is however limiting any gusts from going
higher. The overall forecast for today remains on track currently.
Mainly clear skies will continue into tonight with overnight lows
falling into the mid to upper 50s with winds becoming more
southwesterly.
Tuesday will be nearly identical to today other than warmer and
drier conditions being present. Winds will become more southwesterly
allowing drier air to advect into the area which will lead to RH
values in the low to mid teens mainly along and west of a Tribune to
McCook line. The surface trough will be further SE than today but
not as pinched. The wind field is relatively similar to today, but
due to the lack of pressure gradient think winds won`t be quite as
breezy as today with gusts around 20 knots. Elevated fire weather
will again be expected mainly along and west of a Cheyenne Wells to
Trenton line. High temperatures are currently forecasted to be in
the mid 90s to low 100s with overnight lows falling into the mid
50s. Overnight lows may need to be lowered a bit more as radiational
cooling may play a role as in previous nights with dew points n the
mid 40s to low 50s. A concern I currently have in this scenario is
that winds won`t be light enough for optimal radiational cooling to
occur despite the clear skies, went with a blend of the 5th and 25th
NBM percentile to lower temperatures some. There may be some hazy
skies during the afternoon as smoke from western CONUS fires gets
transported via the eastern periphery of the ridge into the areas,
the 12Z HRRR Vertically Integrated Smoke supports this as well. I am
refraining from introducing into the forecast currently as
observations across southern Montana and the Black Hills don`t
show much impact. There are some less than 9SM visibilities being
reported in southern Montana, but they are closer to the fires so
will that magnitude of haze be able to advect down into the Tri-
State area.
Wednesday looks to be relatively uneventful as the high pressure is
firmly over the plains. Hot temperatures and low RH values look to
be present as afternoon highs again reach the mid 90s to low 100s.
Winds will however be light (less than 10 knots) which will mitigate
and potential wildfire spread.
.LONG TERM...(Thursday through Monday)
Issued at 125 PM MDT Mon Sep 5 2022
Thu: Dry conditions and above normal temps will persist.. via
synoptic subsidence assoc/w a de-amplifying upper level ridge
situated over the Intermountain West, 4-Corners, and central
Rockies -- extending eastward across the Central Plains.
Fri-Mon: A pattern transition will occur in this period as an
amplifying upper level trough.. arising from a complex
amalgamation of shortwave energy in western/central Canada.. digs
southward into the Northern Plains, supplanting the aforementioned
ridge. Meanwhile, an upper level low -- presently centered invof
Ark-La-Tex -- will meander S-SSE and stall invof the TX/LA/MS/AL
Gulf Coast through the remainder of the work week. This feature
could [perhaps] interact with the amplifying northern stream
trough late this week.. introducing additional complexity to the
forecast. Broadly speaking.. expect a cool-down in this period..
as surface pressure rises on the western /subsident/ periphery of
the aforementioned trough drives a cool Canadian airmass southward
through the Northern and Central Plains Fri-Fri night. Forecast
specifics -- e.g. timing of the cold frontal passage, whether or
not precipitation will accompany the front, the southernmost
extent of the front, magnitude/degree of cooling, and longevity
of this cooler airmass (over the weekend) -- cannot reasonably be
ascertained at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 543 PM MDT Mon Sep 5 2022
KGLD expects to see VFR conditions during the 00Z TAF period
starting with southerly winds around 10 kts before the winds
become southwesterly around 8 kts by 08Z. At 15Z, KGLD sees winds
become variable around 6 kts for the remainder of the period.
KMCK also sees VFR conditions during the 00Z TAF period beginning
with southerly winds around 10 kts before the winds become
variable around 6 kts by 08Z. At 23Z, KMCK winds become
northeasterly around 10 kts.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...Trigg
LONG TERM...VINCENT
AVIATION...076
Area Forecast Discussion
National Weather Service Gray ME
1112 PM EDT Mon Sep 5 2022
.SYNOPSIS...
A cold front stalls across southern New England tonight,
bringing cool and wet conditions. Heavier showers and storms
may bring some localized flooding concerns in southern and
coastal areas that receive multiple rounds of rain. Drier air
gradually returns from the north Tuesday, which will culminate
in a mostly sunny and warm second half of the week under high
pressure and upper level ridging.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1112 PM Update...Incoming 00Z guidance suggests moderate to
heavy rain over SW New England will start to push northwards
with heavier rainfall rates moving into southern New Hampshire
after midnight. The last few runs of the HRRR focus the heaviest
rain across the Cheshire and and Hillsborough Counties with
pockets of heavy rain spreading east-northeastward into the
southern White Mountains and extreme western Maine. The greatest
threat for additional flood concerns will be across the
southern tier of counties in New Hampshire. While pockets of
moderate to heavy rain may cross areas that were hardest hit
earlier today from the Conway, NH area into southern Oxford
County, additional rainfall looks to stay under 1 inch with
rates generally less than 0.25 inches per hour. The overall
trend has been for dry northerly flow to win out thus far, with
a downward trend for flood concerns across northern and eastern
portions of the Flood Watch. Have decided to not make any
changes to current Flood Watch and will reassess for the
morning forecast package. Main changes to the going forecast was
to fine tune PoPs based on latest guidance and remove thunder
as there has been little to no lightning observations with the
heavy rain over SW New England. Have also confined heavy
rainfall wording to where the greatest threat for heavy rain
looks to be and removed heavy rainfall wording across portions
of central Maine.
Previously...
7 PM Update...
Have updated the forecast this evening as rain continues to
cross the region. Heavier echoes will continue to enter western
New England before reaching southern and central New Hampshire
and parts of far southwestern Maine. This is supported by the
latest mesoscale models.
Drier air will enter northern areas overnight, ending the
precipitation. Rain, heavy at times will continue across the
south along with patchy fog. Made minor adjustments to
temperatures with this update which will not move much
overnight.
ORIGINAL DISCUSSION...
Continuing to monitor periods of moderate to heavy rainfall
crossing the area which will continue into the overnight hours.
Plenty of moisture both at the surface and aloft will combine
with an upper level disturbance to produce the wet conditions in
a very high PWAT environment. We remain in a marginal risk for
excessive rainfall all the way to the Canadian border where
cells trained earlier in the day.
There remains the possibility of thunderstorms as well, mainly
over southern New Hampshire. This precipitation will be
relatively slow moving and parallel with the upper level flow.
Therefore, training remains possible with locally heavy
rainfall. Flood watches remain in effect for southern and
central areas.
Patchy fog remains a good bet overnight with all of the moisture
in place. Overnight lows will not be that far from their current
levels with the cold air damming continuing across the region.
Expect widespread 50s by morning.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Drier air will gradually filter in from the north on Tuesday,
confining the rain to southern New Hampshire by afternoon. There
will be patchy fog in the morning. Sunshine can be expected over
northern and eastern areas with the aforementioned drying. This
will allow northern areas to have the warmest after
temperatures with highs reaching the upper 60s. Lower 60s can be
expected due to the cloud cover over southern zones.
Drier air will continue to slowly enter the region Tuesday night
as the upper level trough exits to our south. There will still
be sufficient moisture to allow for more patchy fog.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Overview: Surface high pressure will build over New England on
Wednesday, allowing for a return to drier conditions and near
seasonable temperatures. A weak cold front will then approach from
the west on Thursday but other than an isolated shower across the
north and mountains, most places will remain dry. Continued dry
conditions and near seasonable temperatures are then expected until
Monday as upper level ridging settles in overhead.
Impacts: No major weather related impacts expected through the
extended.
Forecast Details: Surface high pressure will begin to build over
northern New England on Wednesday, which will help to finally push
the front responsible for the earlier week`s rainfall southward.
Skies will be partly to mostly sunny with high temperatures
primarily into the 70s and lows into the 40s to 50s from north to
south. A weak cold front will approach western zones on Thursday,
which may result in an isolated shower across mainly the north and
mountains but most areas will remain dry under partly cloudy skies
and near seasonable temperatures.
Gradually warming temperatures to a little above average are then
expected for the end of the week as upper level ridging moves over
the eastern CONUS. Our next chance for showers looks to not arrive
until at least Sunday night and into Monday as high pressure begins
to be pushed offshore ahead of a closed low over the Great Lakes
region.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Short Term...IFR/LIFR conditions expected tonight in all areas
with periods of heavy rain and possibly a thunderstorm, mainly
over southern New Hampshire. Patchy fog will continue under a
northeast wind.
Drier air will gradually filter into the region on Tuesday from
north to south, however low ceilings will allow for IFR or lower
conditions to continue. IFR conditions will continue Tuesday
night over southern areas with VFR conditions developing in
the north outside of patchy fog.
Long Term...VFR conditions will dominate through the extended,
although some patchy BR/FG on Wednesday night may result in
some localized restrictions.
&&
.MARINE...
Short Term...Northeast winds will continue over the waters,
gusting to near SCA thresholds by Tuesday. There will be patchy
fog and limiting visibilities at times. Seas along the outer
waters will run 3 to 4 feet.
Long Term...Winds and seas to remain below SCA criteria
Wednesday through Friday night before seas build to 4-6 ft on
Saturday as a result of a tropical low pressure system well
offshore.
&&
.HYDROLOGY...
Have made some adjustments to the total rainfall map for our
region. Highest totals have been in the North Conway area where
added upslope has enhanced the rainfall in that region. Also,
portions of Oxford County have received over 3 inches of rain as
of 2240Z.
A Flood Watch continues for portions of the forecast area
tonight and into tomorrow. An anomalously moist airmass (PWATs
on the order of 1.75-2.0 inches) and very deep warm cloud layers
(12-14 kft) are indicative of an airmass conducive to efficient
warm rain processes, so long as sufficient forcing is
available. Further, weak low- and mid-level flow is leading to
slow storm movement which will lead to localized high rainfall
amounts.
An upper level trough will approach the region overnight. This
will bring steady precipitation to southern areas tonight and
into tomorrow which will lead to a persistent rainfall across
southern zones, steadily dropping south out of the area on
Tuesday.
Pockets of heavy rain will likely lead to ponding on roadways
and flooding in low-lying, poorly-drained, and urban areas...
with embedded convection and associated high rainfall rates
leading to flash flooding potential due to runoff.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch until 8 AM EDT Tuesday for MEZ012-018>021-023>027-
033.
NH...Flood Watch until 8 AM EDT Tuesday for NHZ004-006.
Flood Watch through Tuesday afternoon for NHZ008>015.
MARINE...None.
&&
$$
UPDATE...Schroeter
NEAR TERM...Cannon
SHORT TERM...Cannon
LONG TERM...Tubbs
Area Forecast Discussion
National Weather Service Lincoln IL
849 PM CDT Mon Sep 5 2022
.SYNOPSIS...
Issued at 239 PM CDT Mon Sep 5 2022
A slow moving storm system will continue to produce scattered
showers and a few thunderstorms into Tuesday, primarily in areas
near and south of I-72. As we get into mid week, high pressure
will control our weather for a few days, allowing temperatures to
warm into the 80s for highs.
&&
.UPDATE...
Issued at 847 PM CDT Mon Sep 5 2022
The region remains under the influence of an upper level low,
which was evident in water vapor imagery north of Lafayette, IN,
at 0130z/830pm. A weak frontal zone in place across southern IL/IN
has resulted in scattered showers and storms south of I-70, but
these have been weakening and are expected to dissipate shortly.
The main focus this evening has been evaluating the fog potential
for overnight. Despite northeasterly winds in the post-frontal
airmass, dewpoints remain relatively moist, in the mid-60s.
Current satellite imagery shows a broken cloud deck in place
across much of central IL, but some clearing across north-central
IL. The latest guidance trended towards greater cloud coverage
overnight, which would limit fog development, but the clearing
across north-central IL leaves some uncertainty. Still think low
stratus will be more prevalent across the CWA early tomorrow
morning, but patchy fog will be possible in any areas that see
prolonged clearing, and the current thinking is that areas
northwest of Bloomington have the best chance at fog development
tonight. Expanded the patchy fog mention in the gridded package,
but otherwise no major changes were made at this time.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 239 PM CDT Mon Sep 5 2022
Early afternoon water vapor imagery shows the upper level
circulation has drifted south to near Kankakee, while the surface
boundaries remain closer to the Ohio River. Most of the rain
activity of late has been near these boundaries, from the St.
Louis area to south of Lawrenceville. Latest HRRR keeps most of
the activity near and south of I-70 through sunset, though stray
showers can`t be ruled out north toward I-72 or so. With the
surface low sliding along the Ohio Valley, additional showers will
be possible on Tuesday across the southeast CWA.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 239 PM CDT Mon Sep 5 2022
Main challenge in the extended period remains with the evolution
of the deep upper wave that will be dropping into the northern
Plains Thursday night and Friday. GFS and European models are
coming into better consensus in closing off an upper low near
Kansas City later in the weekend, while the Canadian solution
favors a position over the western Great Lakes. Initial surge of
rain chances will begin toward Saturday, as moisture surges north
from the Gulf courtesy an upper low over Louisiana, then
additional rain chances arrive with the northern wave on Sunday.
Temperature-wise, mid to late week will be the warmest, with highs
generally in the lower to mid 80s. GFS and European ensembles are
in good agreement with a significant cooldown Sunday and Monday
with 2-meter temperature anomalies of 4 to 6 degrees F below
normal, potentially lingering into the middle of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 619 PM CDT Mon Sep 5 2022
MVFR ceilings have finally started to rise, and any lingering MVFR
cloud decks should gradually climb to VFR over the next hour or
two. The main concern for the rest of the TAF period is the
potential for low stratus and/or fog overnight. Guidance has
trended towards greater cloud coverage and lower ceilings, with
widespread IFR ceilings possible between 10-13z. Most confident in
IFR conditions occurring at CMI/BMI, but may need to expand to
all terminals next TAF cycle if trends continue. Ceilings rise
during the morning Tuesday, reaching VFR around midday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Erwin
SYNOPSIS...Geelhart
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Erwin
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
537 PM CDT Mon Sep 5 2022
.DISCUSSION...(This evening through Monday)
Issued at 249 PM CDT Mon Sep 5 2022
KEY MESSAGES:
- Warming each day through Thursday, then chances for showers return
Friday and the weekend.
The low clouds and fog were slow to dissipate this morning from St.
Cloud southward to Mankato and St. James, but sufficient mixing has
since allowed that to happen. Scattered to broken CU should dissipate
some this evening with the loss of heating. The set up for tonight
doesn`t look quite as good for regeneration of low clouds and fog on
a widespread basis, but patches remain possible.
Temperatures will warm through Thursday this week as mid level
ridging builds in. As a cold front approaches late week, thermal
ridging will arrive Thursday, characterized by 925 mb temps of +25 to
+30C. The GFS, of course, is way too hot with highs in the 105-110
degree range across MN. However, even the NAM, Canadian, and ECMWF
would suggest highs well into the 90s across most of MN, with the
possibility of 100 in the typical downslope areas of west central MN.
The forecast highs were increased a few degrees toward the higher
end of the ensemble envelope given the relatively dry airmass
expected, and the tendency for such situations this time of year to
overachieve.
The cold front will arrive Thursday night and Friday morning. No
precipitation is expected along and ahead of the front, but some
post-frontal showers are likely to form Friday and Friday night. It
doesn`t look like the thunder threat will be too great given the
cooler airmass behind the front and the poor lapse rates aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 526 PM CDT Mon Sep 5 2022
Some VFR cigs around 3.5 to 5.0 kft will slowly diminish overnight
across portions of central/southern Mn, and adjacent west-central Wi.
Otherwise, the only concern is the smoke layer moving across the
Dakotas and into Minnesota overnight, and into Tuesday. The latest
HRRR suggest that this smoke layer will become denser across western
Mn toward morning with cigs around 10.0 to 15.0 kft. I have
introduced SCT150 based on the smoke layer, but this could become
more of an opaque layer if conditions warrant.
KMSP...
No other concerns.
/OUTLOOK FOR KMSP/
WED...VFR. Wind SE 5-10 kts.
THU...VFR. Wind SW 10-20G35 kts.
FRI...VFR. Chc SHRA/TSRA. Wind NNE 15-20G25 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Borghoff
AVIATION...JLT
Area Forecast Discussion
National Weather Service Nashville TN
746 PM CDT Mon Sep 5 2022
...New UPDATE...
.UPDATE...
Issued at 746 PM CDT Mon Sep 5 2022
Updated to remove previous flood watch references from suite of
forecast products. Mentioned continuation of isolated to scattered
showers and thunderstorms across southern and southeastern
portions of mid state region through mid evening hours. Tweaked
currently hourly temperature, dewpoint, and wind speed/direction
grids blending them with associated previously forecasted mid
to late evening hourly gridded values. Current regional
temperature trends continue to support forecasted low values
for tonight. Remainder of forecast continues to be on track.
&&
.SHORT TERM...
(This afternoon through Tuesday Night)
Issued at 132 PM CDT Mon Sep 5 2022
Upper trough is situated to our west this afternoon and already
the deepest moisture is sliding off to the east. The heavy
rainfall that justified keeping the current Flash Flood Watch in
place until this evening has not materialized. At this time, there
is very little active weather in Middle Tennessee, and the HRRR
has consistently shown only scattered cells the remainder of the
afternoon. POP`s will further diminish tonight, but look for more
widespread activity tomorrow as the upper trough swings across the
mid state.
&&
.LONG TERM...
(Wednesday through next Monday)
Issued at 132 PM CDT Mon Sep 5 2022
Rain chances and QPF values look to be quite anemic from
Wednesday through Friday, but then increase starting Friday night
as a strong upper low migrates northward out of the Gulf of Mexico
and pushes a fresh swath of moisture into Middle Tennessee. So
this weekend could be another rainy one. The rainy pattern could
persist into next week as neither the GFS nor the Euro is in a
hurry to push the upper low/shortwave away from Middle Tennessee,
although the GFS keeps a great deal more moisture over the area
than the Euro. Temperatures through the 7-day forecast period look
to stay close to seasonal normals. So the latest 6-10 day outlook
favoring near normal temperatures and above normal rainfall
appears justified.
&&
.AVIATION...
(00Z TAFS)
Issued at 704 PM CDT Mon Sep 5 2022
Shower coverage has decreased this evening with a few isolated
pockets of rain developing, but they seem to be dodging any
terminals for now. The main focus late tonight through tomorrow
morning will be fog development thanks to very saturated surface
conditions and calming winds. All sites could see reduced
visibilities, especially CKV where skies are clearing at this
hour. Even with some mid to high clouds hanging around, BNA and
MQY could still see MVFR vis develop. CSV is most likely to see
IFR visibilities and ceilings late tonight through Tuesday morning
and it could be the afternoon hours before clouds lift to VFR
heights at that terminal. Some showers will be possible again on
Tuesday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 69 85 68 84 / 10 60 20 50
Clarksville 67 82 67 82 / 10 50 20 30
Crossville 65 80 64 77 / 50 50 20 60
Columbia 68 85 67 83 / 20 50 20 40
Cookeville 67 82 66 80 / 50 60 20 50
Jamestown 65 79 64 77 / 20 60 20 60
Lawrenceburg 68 84 67 82 / 50 50 20 40
Murfreesboro 68 86 67 84 / 40 50 20 40
Waverly 68 84 67 83 / 10 40 10 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......JB Wright
SHORT TERM...Rose
LONG TERM....Rose
AVIATION.....Whitehead
Area Forecast Discussion
National Weather Service Pocatello ID
208 PM MDT Mon Sep 5 2022
.SHORT TERM...Tonight through Tuesday night.
Upper level ridge remains over Idaho in the short term period with
continue very hot conditions through Tuesday with low elevation
highs in the 90s again with some locations reaching 100 degrees
again. Winds will generally be light on Tuesday ahead of an
approaching cold front. Heat advisories remain in effect with the
continued pattern of high temperatures around 15 degrees above
normal for early September. Will see 20 to 30 mph wind gusts this
afternoon and evening in the Snake River Plain which will diminish
quickly by sunset. Another couple of days of extreme heat is the
impact short term.
GK
.LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
High pressure and a long-duration heat wave continue, with Wed
perhaps the hottest day of the week (97 to 102 in the Heat Advisory
area). Both deterministic and ensemble model data are finally
starting to show some better agreement in a broad trough cutting
down the ridge and crossing the region Thu/Fri (although 500mb
height cluster analysis still suggests some timing uncertainty). A
few showers/t-storms may accompany this in the Upper Snake Highlands
and portions of the ern highlands, but otherwise a dry/diffuse
frontal passage is expected. Highs Fri may only reach 75-85 degrees!
Late this weekend into early next week, some models hint at moisture
from Tropical Storm Javier being pulled north toward our region
between high Plains shortwave ridging and a PacNW trough (perhaps in
tandem with a weak monsoon push), but confidence remains low. The
NBM now trends PoPs away from Sun and more toward Mon/Tue. 01
&&
.AVIATION...
High pressure continues to support hot, VFR conditions across SE
Idaho. Diurnal winds may yet again manage to gust to 20-25kts today
(lower at KBYI), but winds will trend lighter Tue and Wed. Wildfire
smoke impacts have largely remained north of the TAF terminals, but
based on this AM`s obs and the HRRR have added a low-confidence
mention of 5SM FU tonight into Tue AM at KSUN, KIDA, and KDIJ. 01
&&
.FIRE WEATHER...
Will have 20 to 30 mph wind gusts this afternoon mainly in zone
410 which will die down by sunset. Expect hot and very dry
conditions Tuesday with winds subsiding. Upper ridge collapses
beginning Wednesday as upper level wave and associated cold front
work through Wednesday through Thursday. Have issued a Fire
Weather Watch for zones 475 and 476 for gust winds and low
humidity Wednesday afternoon and evening. Breezy conditions will
continue Thursday wtih the highest winds in the Snake Plain and
zone 410 and 425 as well as 427 and 413 and may need highlights
for winds on Thursday as well although humidity will rise quite a
bit with much cooler conditions expected Thursday behind a cold
front although they will still be quite low. The cooler but still
well above normal temperatures are expected to continue through
the weekend. Some of the operational long term models are
indicating the potential for some rain next week.
GK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM MDT Wednesday for IDZ051>059-075.
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for IDZ475-476.
&&
$$