Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/11/23
Area Forecast Discussion
National Weather Service Amarillo TX
631 PM CDT Mon Jul 10 2023
...New AVIATION...
.SHORT TERM ...
(This evening through Tuesday night)
Issued at 306 PM CDT Mon Jul 10 2023
Strong to severe storms still appear possible for portions of the
Panhandles later this afternoon and evening, but the affects of
lingering cloud cover through the morning have left some doubt as
to the extent of this risk. The Panhandles should dry out
overnight, starting a brief stretch of quieter weather for the
long term.
As of 18z, most low clouds have thinned out and lifted for most
of the area, but much of the central and northeast Panhandles
still have low stratus/cumulus in place. As a result, heating has
been somewhat limited in spots, but any areas that have seen
better clearing through the morning (mostly the southern TX
Panhandle south of I-40) will still have a chance to reach the
low 90s later, especially with downsloping SW winds. Latest
mesoanalysis suggests that capping has already begun to erode over
eastern New Mexico and into the SW Texas Panhandle, but even with
heating, there may still be the slightest of capping holding on
through the evening based on 18z RAP forecast soundings. Dew pts
have held in the upper 60s to even low 70s across the area,
helping to quickly build instability where clearing has occurred
with SBCAPE values analyzed around 3000-4000 J/kg and MLCAPE in
the 1000-2000 J/kg range. Sfc-6km shear is currently about 20-30
kts, but is forecast to slightly improve through the
afternoon/evening as 500mb flow strengthens.
GOES water vapor imagery shows a shortwave crossing the Rockies
into NE New Mexico as it rounds the ridge to our southwest, and is
already generating some showers ahead of it. This activity has
been and should continue to decay as it pushes east and enters
more stable air over the NW Panhandles. As the disturbance
progresses towards the Panhandles, additional waves of convection
should develop off the Rockies and invigorate as they move E/SE
into better moisture. This is where model trends have been muddied
by uncertainty resulting from the widespread clouds holding on
throughout this morning and afternoon. Confidence is still highest
that storms will develop near and south of I-40 towards Lubbock
where destabilization has been greatest and the CAP will likely
erode, allowing any activity to tap into available fuels and
potentially become severe. Further north, scattered showers and
storms may still develop later this afternoon, but their ultimate
intensity as well as whether or not they will become surface based
is in question. HRRR run-to-run trends have generally been less
aggressive through the day with storm coverage and intensity for
this afternoon and evening, likely catching on to the detriments
from the clouds this morning. Latest guidance suggests that the NE
combined Panhandles may also have a better shot at strong to
severe storms after 7 PM as a broken complex of storms drops down
from SE Colorado through the evening. DCAPE values of 1000-1500
are in place and could further improve as sfc heating enhances low
level lapse rates, so any storms that can become surface based
will have the potential to produce wind gusts in excess of 60 mph.
There is still a chance though that storms may remain rooted
above the cap and fail to get these wind gusts to the sfc. Our 12z
observed sounding this morning revealed warm temperatures above
500mb that even the approaching shortwave may fail to sufficiently
cool in order to support large hail potential, especially if deep
layer shear doesn`t improve very much. PWATs of 1.0-1.5 inches
will be supportive for heavy rainfall rates capable of also producing
flash flooding, especially in the northeast where flooding has
already been a recent issue.
Harrel
&&
.LONG TERM ...
(Wednesday through next Sunday)
Issued at 306 PM CDT Mon Jul 10 2023
Mid to upper level high pressure is expected to prevail over much
of the Desert Southwest into the Southern Plains in the extended
period. With the high pressure daytime highs are expected to be
quite warm, starting tomorrow with highs returning to the upper
90s to low end triple digits. Persistent upper level low pressure
over the Hudson Bay into portions of Manitoba and Ontario, Canada
will create troughing in portions of the Upper Midwest into the
northeastern CONUS. This trough is expected to help shift the high
pressure westward sending the FA into northwest flow aloft.Also,
it will create some shortwaves through northwest flow creating
better chances for thunderstorms each and every night starting
with Thursday night. The NBM did have some slight chance pops for
Wed night but has since trended dry.
Tomorrow, Tuesday, looks to remain dry, giving the combined
Panhandles a break from thunderstorms. The big question for
tomorrow is how strong of a surface trough will impact the western
FA. Higher dewpoints are expected to stay in the east with upper
60s to lower 70s. Some lower dewpoints are looking to push into
the far western portions of the FA. This will help temperatures
get a few degrees warmer in the west. Looking at progged H85
temperatures the west will also see a bit of a LLTR helping to
warm things up nicely. Models disagree about how far east some of
the drier air moves in the combined Panhandles. This is leading
to some concerns for Palo Duro Canyon to reach Heat Advisory with
heat indices of 105 or higher with a temperature especially if the
canyon floor hangs onto 60 degree Td`s. Even with raising the PDC
floor a couple of degrees above the NBM/Conshort, the actual
temperature is progged to be around 102/103. Going into Wednesday
the canyon floor is progged to hit 105 and is looking to need a
Heat Advisory regardless of the humidity Wed afternoon.
Thu and Fri, as the high pressure gets shifted westward some
relief may come to the northern combined Panhandles with
temperatures only making it into the lower 90s as opposed to the
upper 90s. The NBM has given slight chance pops to much of the
area for Thu night, favoring the northern FA. It is not until Fri
night when the FA sees chance pops, favoring the northern FA once
again. H5 temperatures are starting to hit that -6 to -4 degrees
C range, which will limit the chances for large hail. At this time
cannot rule out severe storms with damaging winds being the main
threat Thu into Fri night.
With even further shifting of the ridge to the west daytime highs
over the weekend are progged to be in the mid 80s to lower 90s
with continued chances for precipitation with the northwest flow.
36
&&
.AVIATION...
(00Z TAFS)
Issued at 618 PM CDT Mon Jul 10 2023
Main concern for this package will be the potential for
thunderstorms over the next 6 to 8 hours or so. Storm coverage is
uncertain, and latest trends suggest activity may be isolated a
best. There is an area of storms up in KS with some lighter
activity further south into eastern NM, but these may struggle to
hold together. Still, even showers could produce some gusty
outflow winds and if a storm does manage to form, large hail and
damaging winds can`t be ruled out. Best storm chances are before
midnight at all terminals, with KGUY having the highest chance
overall. Otherwise, VFR conditions are expected with some periods
of mid level clouds. Southerly winds are generally expected at 5
to 15 knots.
Ward
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 68 99 74 101 / 40 0 0 0
Beaver OK 66 94 70 99 / 20 0 0 0
Boise City OK 63 95 67 96 / 40 0 0 0
Borger TX 69 101 75 104 / 30 0 0 0
Boys Ranch TX 68 101 73 103 / 30 0 0 0
Canyon TX 67 99 73 101 / 50 0 0 0
Clarendon TX 67 97 74 99 / 50 0 0 0
Dalhart TX 63 97 67 99 / 30 0 0 0
Guymon OK 65 95 69 98 / 60 0 0 0
Hereford TX 67 100 72 102 / 50 0 0 0
Lipscomb TX 66 95 71 99 / 30 0 0 0
Pampa TX 66 96 73 99 / 40 0 0 0
Shamrock TX 67 95 72 99 / 30 0 0 0
Wellington TX 69 98 73 101 / 40 0 0 0
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory from 2 PM to 9 PM CDT Tuesday for TXZ317.
OK...None.
&&
$$
SHORT TERM...38
LONG TERM....36
AVIATION...07
Area Forecast Discussion
National Weather Service La Crosse WI
1059 PM CDT Mon Jul 10 2023
.DISCUSSION...(This evening through Monday)
Issued at 245 PM CDT Mon Jul 10 2023
Key Messages:
- Scattered storms, a few potentially strong/severe, developing late
this afternoon/evening. The main hazards are strong winds
perhaps some hail this evening.
- Maybe another low chance of strong to maybe severe storms on
Tuesday Night south of Interstate 90.
- Periodic shower and thunderstorm chances from Wednesday Night
through Monday. Both the heavy rain and severe weather threats
look to be south and southwest of the area.
Tonight:
Early this afternoon a cold front stretched from central MN to
northern WI with gusty southwest winds pushing temps well into the
80s. A few showers were occurring in the vicinity of the boundary in
north-central WI. Overall, expect coverage of storms to increase
late this afternoon/evening along the front where moisture
convergence is maximized and broad large scale lift with a shortwave
trough occurs. Deeper boundary layer mixing/large dew point
depressions will limit instability somewhat, with the RAP indicating
up to 1000-1500 J/kg of MLCAPE along the boundary. Will have to
watch moisture trends through the afternoon, as a more aggressive
mixout, as the HRRR suggests, could limit/impact coverage of storms
during the evening, but the HRRR has initialized too dry so far
early this afternoon. A few CAMs have also shown some pre-frontal
storms developing with modest low-level convergence/perhaps a weak
shortwave trough by late afternoon with little capping, but
confidence in this evolution is lower.
The stronger deep layer shear will lag the front, while some
increase in low-level shear is expected with a modestly increasing
low-level jet during the evening. With the linear forcing and along
boundary shear vectors, some linear organization of storms is
possible before storms weaken overnight with loss of instability.
Locally damaging winds are the primary threat given the deeply mixed
boundary layer although a few storms within the first few hours of
storm initiation could also produce marginally severe hail. Given
the timing of the front, the higher chances for any severe storms
looks to be near or north of I-90 this evening.
Tuesday Night into Wednesday:
Another shortwave trough will eject out of the Northern Plains
on Tuesday evening and move southeast through the Mid and Upper
Mississippi River Valley on Tuesday night and Wednesday morning.
There is still plenty of uncertainty on the northern extent of the
severe weather threat with this wave. Elevated CAPES look to be
generally less than 500 J/kg along and south of Interstate 90.
Unlike tonight, there is much better 0-6 km shear (around 40
knots). Much of this shear is located in the 0-3 km layer.
However, with the area being north of warm front, we will not
likely realize all of this shear. As a result, took a look at the
1-3 km layer shear and it is generally less than 20 knots. If a
storm happens to be a bit closer to the warm front, the effective
shear could potentially reach 30-35 knots. The CAMs currently have
a wide variety evolution of convective systems on Tuesday night.
At this time, it looks like the best chances of severe weather
will be mainly across northern and central parts of Iowa and
Illinois. The Storm Prediction Center currently has a marginal
risk for our far southern counties and that seems reasonable. The
main severe weather threat would be hail.
While there will be likely (40-80% - highest along and south of
Interstate 90) be rainfall, the heaviest rain looks to fall south
of our area. Currently, have rainfall totals up to a quarter inch
north of Interstate 90 and a quarter to a third of an inch across
the remainder of the area. Depending on the location of the
storms on Tuesday night, rainfall totals could be in the excess of
1 inch. The grand ensemble suggest the probabilities of this
occurring in less than 15%.
Wednesday Night through Monday...
The 10.12z models are in general agreement that there will be an
active northwest flow across the northern US. This could result
in periodic showers and storms. At this time, it looks like the
heaviest rain and severe weather threats would be mainly southwest
and southwest of the area. As typical in these situations, the
timing of these waves are highly uncertain; thus, stayed close to
the NBM precipitation chances.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1056 PM CDT Mon Jul 10 2023
Thunderstorms are expected to diminish and be south of LSE and RST
by 06Z with VFR conditions expected to prevail through the TAF
period. Dry conditions are forecast for much of Tuesday, but a
20-30 percent chance of showers and storms will move into
southeast Minnesota Tuesday evening.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...Boyne/JM
AVIATION...JAW
Area Forecast Discussion
National Weather Service Boston/Norton MA
950 PM EDT Mon Jul 10 2023
.SYNOPSIS...
Showers and a few thunderstorms will come to an end this
evening. Mid summer weather conditions return beginning Tuesday,
with highs into the lower 90s for many of us on Wednesday.
Chances for thunderstorms, along with humid conditions, return
for Thursday and Friday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10 PM Update...
Showers have all but come to an end across our region save for a
few light showers across the high terrain of Worcester County
and the downslopes of the Berkshires. Fortunately, we wont see
much additional precipitation out of these radar returns.
Clearing develops quite rapidly behind the exiting line of
showers earlier this evening, prompting us to improve the cigs
and vsby forecast overnight. Some fog is still holding on across
the eastern MA coastline, but should dissipate as winds continue
to switch to the W. Some low/mid level clouds will filter in
across NW MA this evening but dropping dewpoints should allow
those to dissipate as well.
7PM Update...
Showers continue to dissipate this evening and should end
before midnight. Low clouds and fog should also dissipate from
west to east as winds flip around to the west. There is a low
chance for radiation fog in low lying areas tonight given the
high level of ground moisture due to rain and dew points in the
mid 60s.
345 pm update...
monitoring a band of showers and thunderstorms stretching from
central MA southward into eastern CT. These have formed along a
surface convergence boundary associated with a surface trough,
combined with a modest amount of surface instability. SPC
mesoanalysis indicates lesser instability to the east of that
line, likely due to the southeast flow advecting in a more
stable marine influenced airmass. Latest hi-res models suggest
that this line may go another 30-40 miles eastward before
dissipating. This would be great news, especially across
portions of northern RI (and the PVD area) which got soaked a
little earlier today, so even a little bit of additional
rainfall would cause problems. Have made adjustments to the
hourly PoPs based on the latest HRRR and RAP models, and go with
the idea that the convective line will be dissipating between
6-7pm.
With sunset, we lose the instability and that means most of the
shower activity should dissipate. Could still be a rogue shower
or two through midnight, especially near that surface trough, as
it slowly moves eastward and eventually offshore. Once that
happens, the rest of the night should be quiet. Still rather
high humidity, so lows in the 60s.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
345 pm update...
High and dry for the day. Upper level trough will push offshore
early in the day, setting us up with dry west/northwest flow.
Good amount of sunshine will promote boundary layer mixing up to
5000ft or so. Some winds of 20-25kts up that high, so we could
see occasionally breezy conditions, but overall not bad. 850mb
temperatures will be around 15C, so that supports surface
temperatures about 30C. Stuck with the NBM which had highs in
the mid/upper 80s across the region. Don`t think there will be
any significant sea breeze tomorrow given the westerly flow, but
if one does form, it will be pinned pretty much to the coast.
Quiet Tuesday night. Not an overly dry airmass with dewpoints in
the 60s, so overnight lows will be in the 60s.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
345 pm update...
Given the ongoing weather today, the extended forecast is pretty
much NBM, and not much different than previous shift had. A few
highlights:
Wednesday: 850mb temperatures up around 17C, so that suggests we
should be able to reach the 90F level, especially across the
lower elevations. Dewpoints will be in the lower to mid 60s, so
although a bit muggy, it won`t be oppressive. Small risk of
afternoon convection, primarily across the higher terrain of
western MA.
Thursday/Friday: Looks like unsettled weather returns. Upper
trough to our west sets up, with shortwaves rippling through the
flow that if everything works out perfectly with timing, will
result in additional showers/thunderstorms especially during the
daytime. Flow turns more southwest, so we return to a humid
airmass, thus potentially another round of threat for locally
heavy rainfall. Coordination with WPC to add in a slight risk in
their most recent ERO for both Thursday and Friday -- primarily
across western sections of SNE.
Saturday/Sunday/Monday: Broad southwest flow continues at all
levels. Looks like what mid-summer is supposed to be here in SNE
with warm and humid conditions with the chance of showers and
thunderstorms. NBM seems to offer the best forecast at this
point as those nuance details (such as low level boundaries,
timing of shortwaves, exact amounts of low level instability)
are too hard to pin down this far out in time. Thus we have
pretty much a climo forecast - highs in the 80s with a 40-50%
chance of showers/t-storms each day.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
00z Update
Overall moderate confidence.
Remaining showers will quickly come to an end this evening
across BOS and BED. VFR across western terminals tonight.
LIFR/IFR improving to MVFR/VFR around 06z for eastern terminals.
Winds tonight will shift west at 5-10 knots behind the front
and should remain high enough to keep widespread fog from
forming overnight
VFR conditions should be in place for much of the region by 12z
Tuesday, and that should continue for the entire day. VFR into
Tuesday night as well.
BOS Terminal...Moderate confidence. LIFR/IFR this evening with
lingering showers. Improving conditions overnight, should be
VFR by the morning push. Winds start out of the east and shift
to the west around 03-04Z.
BDL Terminal...High confidence. VFR tonight with a west wind at
5-10 knots
Outlook /Wednesday through Saturday/...
Thursday: VFR. Breezy. Chance SHRA, isolated TSRA.
Thursday Night: Mainly VFR, with areas MVFR possible. Breezy.
Chance SHRA, isolated TSRA.
Friday: Mainly MVFR, with areas VFR possible. Breezy. SHRA
likely, isolated TSRA.
Friday Night: Mainly VFR, with local MVFR possible. Breezy.
Chance SHRA, isolated TSRA.
Saturday through Saturday Night: VFR. Chance SHRA, isolated
TSRA.
Sunday: Chance SHRA, isolated TSRA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
345 pm update
High confidence
Showers, perhaps an isolated thunderstorm, and areas of fog will
be the primary weather through this evening. However improving
conditions expected after midnight and lasting through Tuesday
night. Winds will ultimately turn westerly after midnight and
last Tuesday. Speeds will remain less than 20 kts, so wave
heights will generally be 4ft or less through the period.
Outlook /Wednesday through Saturday/...
Thursday: Winds less than 25 kt.
Thursday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas locally approaching 5 ft. Chance of
rain showers, isolated thunderstorms.
Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of seas approaching 5 ft. Chance of rain
showers, isolated thunderstorms.
Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 20 kt. Areas of seas approaching 5 ft. Chance of
rain showers, isolated thunderstorms.
Saturday through Sunday: Winds less than 25 kt. Seas locally
approaching 5 ft. Chance of rain showers, isolated
thunderstorms.
&&
.HYDROLOGY...
700 pm update...
Attention the next couple of days turns to the Connecticut
River. Lots and lots of rain further north will be sending quite
a surge of water our way. River Flood warnings already raised
for points from Springfield northward. Expect it to crest into
the moderate levels. Would think we will raise warnings for the
river in CT as well sooner than later as the flood crest should
be getting down there starting Tuesday. We will await updated
forecasts from the NERFC before making those decisions.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...Nash
NEAR TERM...KP/KS/Nash
SHORT TERM...Nash
LONG TERM...Nash
AVIATION...KP/Nash
MARINE...Nash
HYDROLOGY...
Area Forecast Discussion
National Weather Service Burlington VT
1012 PM EDT Mon Jul 10 2023
.SYNOPSIS...
Multiple rounds of moderate to heavy rain is ongoing. Widespread 2
to 5 inches of rain with locally 7 inches have already fallen
and an additional 1 to 3 inches are expected through Tuesday.
Flash flooding caused by excessive rainfall continues to be
possible through Tuesday morning, though the event is currently
evolving to more of an areal and main stem river flood threat
as the rainfall rates decrease but river levels continue to
respond to all the rainfall in the last 24 to 36 hours. Muggy
and unsettled conditions continue through the rest of the week.
More rain is forecast Thursday into Friday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 1010 PM EDT Monday...Once again, most of our attention and
manpower is currently directed toward the ongoing flooding, so
updates have been light. Main focus of course was PoPs, and
noticed models have shifted precip toward northern New York
later tonight. Increased PoPs in those areas and added some
patchy fog many spots as it`s not out of the question with all
this rain. As always, please use caution and turn around, don`t
drown. Previous discussion below...
Previous discussion:
* Flash flooding caused by excessive rainfall continues to be
possible through Tuesday morning, though the event is currently
evolving to more of an areal and main stem river flood threat as
the rainfall rates decrease but river levels continue to respond
to all the rainfall in the last 24 to 36 hours.
A potent 572 Dm low has now closed off near Oswego, NY with the
upper level trough taking on a negative tilt along with upper
level diffluence over our region. The 12z HRRR and NAM 3km
picked up on this development and is now backing/blossoming the
precipitation over the populated Winooski River valley from
Montpelier to Burlington. In addition, the favorable left exit
region of the 250mb jet streak is now nosing into Connecticut.
The overall impressive jet dynamics have led to some convective
showers and heavy rainfall with embedded thunder pivoting up the
I-89 corridor and the Winooski River valley into the Champlain
valley. So updated the 6 hour QPF for this afternoon using some
of the hi- res 12z CAM guidance. In addition, WPC now has most
of VT under the High Day 1 Excessive Rainfall Outlook, which
means that widespread flash floods are likely with significant
to potentially catastrophic impacts. The existing Flash Flood
Warnings across northern VT might need to be updated/upgraded in
severity. Stay tuned and always remember turn around, don`t
drown.
On Tuesday, we will have to monitor the potential for a low-
level jet of 35 to 45 knots lifting north across the region as
the upper low intensifies. Forecast guidance suggests mid-level
cooling may allow some of these winds to mix to the surface of
the Northeast Kingdom. With such saturated soils, felling trees
would be easier than normal. Wind gusts 20 to 30 mph will be
possible across portions of northern NY and VT on Tuesday
afternoon. Otherwise, while the heavy rain threat comes to an
end by Tuesday morning, river levels will continue to respond to
the deluge of rain in the last 24 to 36 hours. Winooski, Lamoille and
Mad River expected to crest at major flood stage later tonight
or on Tuesday before gradually receding.
Please continue to take this flooding event seriously, have
multiple ways to receive real-time NWS weather alerts and have
contingency plans in place.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 343 PM EDT Monday...A frontal boundary will move slowly over
northern New York and Vermont on Wednesday, bringing a widespread
chance of thunderstorms to our area. There remains fair amount of
uncertainty on how exactly this will play out as models have not
come in line. Coming on the heels of Monday`s extreme rainfall and
flooding, we will need to keep our eyes on continued impacts in any
areas that receive another round of precipitation.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 343 PM EDT Monday...A low pressure system well to our north
will continue to steer shortwaves from the southwest into the North
Country through the weekend. Expect warm and humid conditions to
persist with periods of rain every day through the long term. The
chance of thunderstorms is highest for Thursday and Friday while the
weekend appears to have less instability, although rainfall will
continue. Model consistency provides us with a fair amount of
certainty through Thursday night while the timing and location of
precipitation becomes less clear as we move into the weekend.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...Very messy out there in terms of flight
categories this evening, with anywhere from VFR to IFR
conditions and a mix of lowered ceilings and visibilities plus
variable winds. Main focus of this 24 hour TAF period will be
the gradual improvement in conditions- lifting of cigs and
lessening of the heavy, vis- lowering rain until conditions turn
drier. Thinking earlier improvement to VFR at NY sites, around
05Z-12Z Tuesday, while VT sites could be lifting to VFR around
12Z-16Z Tuesday. LLWS no longer looks to be a big issue for this
TAF period. Stay safe out there!
Outlook...
Tuesday Night: VFR. Slight chance SHRA, Slight chance TSRA.
Wednesday: VFR. Chance SHRA, Chance TSRA.
Wednesday Night: VFR. Slight chance SHRA, Slight chance TSRA.
Thursday: Mainly VFR, with local MVFR possible. Chance SHRA.
Thursday Night: Mainly VFR, with areas MVFR possible. Likely
SHRA, Slight chance TSRA.
Friday: MVFR/IFR conditions possible. Chance SHRA, Chance TSRA.
Friday Night: Mainly VFR, with local IFR possible. Chance SHRA.
Saturday: Mainly VFR, with areas MVFR possible. Chance SHRA,
Chance TSRA.
&&
.HYDROLOGY...
** WPC has updated their Day 1 Excessive Rainfall Outlook and
most of VT is now in their Day 1 High risk ERO, which means
that widespread flash flooding is expected/likely.
We remain in a Moderate Risk from the Adirondacks east, with an
embedded High Risk ERO along the eastern slopes of the
Adirondacks, Champlain Valley, and across the spine of the Green
Mountains. This indicates numerous flash flooding is likely.
There will be two rounds of widespread heavy rainfall. One is
ongoing, which is producing rainfall amounts between 0.50" and
2.50", locally up to 3.50" of rain. After a brief lull, rainfall
will once again blossom during the day, peaking this afternoon
into evening. There is even potential for a third round of
moderate rainfall overnight hours as wrap around precipitation
develops behind an upper low. Given the saturated ground and
antecedent high river/creek levels, bottom line is that it will
not take a whole lot of rain to cause widespread issues.
Overall, we continue to forecast widespread 2 to 5 inches of
rain with locally 7+ inches especially along and near the spine
of the Green Mountains. Expect washed out roads and culverts,
fast- responding creeks spilling out of their banks, as well as
widespread poor drainage urban area flooding. Even outside of
the stratiform widespread rainfall, convective elements will be
possible this afternoon, leading to locally enhanced rainfall
with a quick inch or two in as little as an hour. By this
evening into overnight hours, and heading into Tuesday, the
flooding mode will transition from flash flooding to more of
area and main stem river flooding. Typically vulnerable basins
including the Mad River in Moretown, Otter Creek in Center
Rutland, Winooski River in Essex Junction and Ausable River at
Ausable Forks are expected to reach minor and moderate flood
stage on later today, Tuesday, and even into Wednesday.
The main takeaway is that if you are in a Flood Watch, please take
this flooding event seriously, have multiple ways to receive real-
time NWS weather alerts and have contingency plans in place.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Flood Watch through Tuesday evening for VTZ001>011-016>021.
NY...Flood Watch through Tuesday evening for NYZ027-028-030-031-034-
035.
&&
$$
SYNOPSIS...Chai
NEAR TERM...Chai/Storm
SHORT TERM...Langbauer
LONG TERM...Langbauer
AVIATION...Storm
HYDROLOGY...Chai/Hastings
Area Forecast Discussion
National Weather Service Caribou ME
918 PM EDT Mon Jul 10 2023
.SYNOPSIS...
Low pressure will lift to the Gulf of Maine tonight, then cross
the region Tuesday. A weak frontal boundary will stall across
the region Wednesday. A series of disturbances will then cross
the region Thursday into Saturday.
&&
.NEAR TERM /THROUGH TUESDAY/...
920PM Update...No major changes to the forecast for this update.
Rain continues to move into the region with some moderate convection
per obs, though staying below heavy rain.
Previous Discussion...
A negatively tilting upper trof/closed low will help support
low pressure which will lift to the Gulf of Maine tonight, then
cross the region Tuesday. Showers early this evening, will
transition to a steadier rain overnight. Rain will persist
through Tuesday morning then taper to showers during the
afternoon. Will also have enough elevated instability to support
isolated thunderstorms tonight through Tuesday morning.
Isolated/scattered thunderstorms are then expected Tuesday
afternoon. Deep moisture, upper level forcing, low level
convergence and precipitable water values of up to around 2.00
inches will support locally heavy rains overnight into Tuesday
morning. Potential training precipitation and embedded
convection could lead to the risk of localized flash flooding
later tonight into Tuesday morning. The greater rain totals are
expected north and west of a line from Greenville to Houlton.
Generally expect rainfall totals of 1 to 2 inches in these
areas. Rainfall totals Downeast are generally expected to be
less than an inch. However, locally heavier totals are possible
regionwide with any convection or training of precipitation.
Patchy/areas of fog are also expected tonight into Tuesday
morning, most extensive Downeast. Low temperatures tonight will
generally range from around 60 to the mid 60s across the region.
High temperatures Tuesday will range from the lower to mid 70s
across much of the region, with upper 60s to lower 70s along the
Downeast coast.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Tuesday night precipitation will taper off, but fog will be a
concern again with plenty of available moisture and clearing
skies overnight. Overnight lows should remain in the low 60s.
On Wednesday, a weak cold front will come through in the
afternoon. Thunderstorms will trigger along the front as it
moves through. CAPE values ahead of the front will be in the
2000 to 2500 J/kg range, which is on the higher end of what we
have been seeing this year. At the same time, 0 to 6 km shear
will increase to 20 to 30 knots. Freezing levels will still be
high, around 12k feet, but with increased shear and large CAPEs
will increase the potential for large hail and gusty winds in
any storms that form. Heavy rainfall will also continue to be a
concern since there PWATs will not decrease and there will be
potential for training for a short period along the front.
Melting hail may also contribute to heavy rainfall. Have decided
not to add any enhanced wording to the forecast for now, but it
may be considered as that period gets closer in time.
In spite of the cold front moving through Weds, by Thursday, the
cool(er) air aloft will retreat to the north, and southerly flow
will bring a resurgence of hot, humid air. Therefore, afternoon
highs will still reach the mid 80s Thursday afternoon, with
continued muggy conditions. Chances of showers and thunderstorms
will continue, in particular on Thursday afternoon as
instability will increase with the warm air mass in advance of
the next round of rain expected Thursday night.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Overall weather pattern remains the same through the weekend. A
negatively-tilted longwave trough will remain anchored off to
the NW, with the upper low center over central Canada. This
keeps northern New England in southwest flow aloft, with a warm
tropical air mass remaining overhead. Thus, the long term
forecast is just a rinse and repeat, with several shortwaves
rotating through the pattern and causing periods of rainfall,
with afternoon thunderstorms. Right now, the hottest days look
like Thursday and Monday, with 850 hPa temps peaking at around
17 C both days. Monday is a little more of a question mark on
high temps, because there may be enough lingering clouds from
the previous system to temper any solar heating.
As for bands of precipitation, right now the models are in good
agreement on another period of rainfall Thursday night through
Friday morning. Right now probabilistic guidance is indicating a
high likelihood (60 to 70% chance) of PWATs between 1.5 to 2.0
inches. Since this is similar to what we have seen in recent
systems, it would indicate there could be a risk of more intense
rainfall in embedded showers and thunderstorms, mainly over
western Maine again. On Saturday, another trough is likely to
bring more precipitation. However, the timing on this feature is
a lot more uncertain, and model ensembles are not showing a
distinct cluster of solutions indicating whether this will be
Saturday morning or afternoon, and how long this precipitation
will stick around. A second wave on Sunday provides a similar
problem on timing. So although confidence is high that the
weekend will be rainy, confidence is low on timing and whether
the rain will arrive in the form of thunderstorms.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: Across northern areas, VFR/MVFR early tonight
lowering to IFR/LIFR overnight. Showers early, then rain. Rain
could be heavy at times. Isolated thunderstorms. Patchy fog
overnight through early Tuesday. Across Downeast areas tonight,
IFR/LIFR with occasional VLIFR. Showers early, then rain. Rain
could be heavy at times. Isolated thunderstorms. Areas of fog.
IFR/LIFR regionwide Tuesday. Rain tapering to showers during
the afternoon. Rain possibly heavy at times during the morning.
Isolated/scattered thunderstorms. East/southeast winds around
10 knots tonight. Variable winds 5 to 10 knots Tuesday.
SHORT TERM:
Tuesday night...MVFR, improving to VFR, except
possible IFR in FG, mainly for northern sites. Chance showers
early. E to SE wind 5 to 10 kt, becoming S to SW.
Wednesday...VFR/MVFR. Chance showers and afternoon thunderstorms.
SW to W wind 5 to 10 kt.
Wednesday night through Thursday...MVFR improving to VFR. Variable
wind 5 to 10 kt.
Thursday night through Friday...VFR/MVFR, occasional IFR in rain.
Chance showers and thunderstorms.
Friday night...MVFR/occasional IFR for northern sites. Possible fog.
Saturday...Mainly VFR. Possible MVFR early. Chance showers and TS.
&&
.MARINE...
NEAR TERM: Winds/seas below small craft advisory levels tonight
through Tuesday. Extensive fog tonight through Tuesday with
significant visibility reductions. Rain tonight into Tuesday.
Isolated thunderstorms tonight, scattered thunderstorms Tuesday.
SHORT TERM: Winds and seas remain below SCA for the long term
forecast. Possible return of dense fog Tuesday night.
&&
.HYDROLOGY...
Climatologically anomalous moisture content over very saturated
soils with showers and storms developing will pose a threat of
Flash Flooding across the Moosehead Region northward into the
western St. John Valley into this evening. For this evening
PWATs are in the 1.75-2.00 inch range across the area which is
between the 97-99.5 percentile range. Latest RAP and LAPS
analysis show some tall skinny CAPE along with decently moist
low and mid levels. Freezing levels are 12-13kft which indicates
a strong warm cloud processes will be dominant in precipitation
production. Although CAPE is weak there is enough for convection
to tap into the production of rainfall rates >2" per hour but
even >1" per hour poses a flash flood risk. Due to recent
thunderstorms in the past couple days the North Woods 1-3hr
Flash Flood Guidance is 1-1.5". 14 day rainfall remains well
above 200-300% of normal across large portions of the CWA.
Tonight as a boundary begins to work northeast through the area
we will see a heavy rain threat across the area. The greatest
potential of heavy rain will extend from the Central Highlands
northward into the Crown with the "bullseye" over the North
Woods. The SE flow will support upslope ascent across the
Longfellow Mountains. As the 500mb trough approaches this will
place us in the left-exit region of the 250mb jet stream
supporting strong upper level divergence aiding surface lift.
Although activity will be mainly along and ahead of a line
progressing decently across the area based on latest CAMs expect
torrential downpours to pose a flood threat.
There remains a potential of rapid small stream and creek
flooding combined with excessive runoff flash flooding concerns
through tonight into tomorrow. This will also pose a risk to
campers, hikers and washouts to dirt roads and ATV trails. Those
heading out into the North Woods should stay alert for rapid
changes to streams and creeks and have a way to get warnings in
no cell signal areas. At this time there is no flood threat on
the larger rivers except the upper West Branch of the Penobscot
and upper Piscataquis which are prone to flash flooding. WPC
continues a slight risk in the Excessive Rainfall Outlook for
tonight and a marginal risk for Tuesday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...LaFlash/Norcross
Short Term...LF
Long Term...LF
Aviation...LaFlash/Norcross/LF
Marine...LaFlash/Norcross/LF
Hydrology...
Area Forecast Discussion
National Weather Service Cheyenne WY
532 PM MDT Mon Jul 10 2023
.SHORT TERM...(This evening through Wednesday night)
Issued at 210 PM MDT Mon Jul 10 2023
Forecast concerns continue to deal with isolated severe storms
today and Tuesday...followed by elevated to locally critical fire
weather conditions Tuesday and Wednesday.
Currently...Surface trough lays across northeastern Colorado into
the southern Panhandle...northeast into south central South
Dakota this afternoon. 1016mb surface high analyzed near Craig
Colorado with surface ridging into central Wyoming. Radar showing
isolated convection developing over the north Laramie Range and
near the state line in northern Colorado. Storm motions from
northwest to southeast. 1PM dewpoints range from 64 at Sidney to
37 at Rawlins.
Some concern this afternoon as SPC mesoscale SBCAPEs up near
4000J/KG over the southern Panhandle currently. SBCAPE ranges from
2000J/KG over Goshen County to eastern Laramie County to this
4000J/KG bullseye over Sidney. HRRR simulated radar does show
possibility of a few severe storms across Niobrara County to maybe
Alliance as well as just south of Kimball and Sidney after 4PM.
Good news...RAP instability on the decrease across the southern
Panhandle after 00Z. So any severe storms that develop between 4PM
and 6PM likely to be short lived.
Dry air surges east Tuesday as upper ridge continues to build over
the CWA. PWATS in the Panhandle start out around an inch in the
Panhandle Tuesday morning...but fall to .5 inch by 00Z. Held on to
some isolated showers and storms for Tuesday afternoon...mainly in
the northern Panhandle...where these high PWATS will be the last
to decrease. This matches up well with SPC`s Marginal Risk area
for Tuesday.
Wednesday looks mainly dry and have undercut NBM guidance on PoPs
Wednesday afternoon as a really dry and warm as upper ride firmly
over the area. Can`t rule out some isolated afternoon convection
over the northern Panhandle Wednesday afternoon. Most other areas
dry.
.LONG TERM...(Thursday night through Monday)
Issued at 210 PM MDT Mon Jul 10 2023
An upper level ridge will remain in place across the southwest CONUS
through much of the long term period with multiple shortwave
passages late this week under northwest flow leading to the chance
of showers and thunderstorms Thursday and Friday afternoon. Models
are split on Thursday with the Euro keeping low level moisture
farther west into WY, but strong westerlies and downslope flow will
likely lead to the moisture boundary farther east into the NE
Panhandle. Kept PoPs around 20-30% Thursday afternoon and again
Friday evening with a frontal passage. Temperatures will drop a few
degrees headed into the weekend, but still remain only slightly
below normal in the upper 70s to low 80s. Post frontal upslope flow
could lead to increased morning cloudiness Saturday and Sunday along
with isolated afternoon showers and thunderstorms under northwest
flow aloft.
This upper level ridge will begin to build over the Intermountain-
West late this weekend with 500mb height rises across the area.
Latest NAEFS guidance has 700mb temps approaching climatological
90th percentile values for mid-July, but uncertainty still remains.
Ensemble systems still showing multiple camps with the strength and
eastward progression of the upper level ridge which will be highly
dependent on the placement of an upper level low near the Great
Lakes region. Latest NBM has a fairly high spread in high
temperatures next Monday for Cheyenne with an IQR from 76F to 89F.
Will need to monitor forecast trends for the potential of late July
summer late, though as it looks right now temperatures should not
approach record levels.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 528 PM MDT Mon Jul 10 2023
Ridging aloft and a relatively dry atmosphere will keep skies
mostly clear with only scattered clouds from 8000 to 10000 feet
AGL at times. Winds will gust up to 22 knots at Cheyenne until
02Z, and to 30 knots at all Wyoming terminals after 15Z Tuesday.
&&
.FIRE WEATHER...
Issued at 210 PM MDT Mon Jul 10 2023
Surface high pressure over northwestern Colorado this afternoon
extends north into Carbon County and central Wyoming. Fairly dry
air west of the Laramie Range with afternoon humidity in the upper
teens to low 20s. East of the Laramie Range...humidity quite
higher with upper 40 percents in the Panhandle. A few storms are
possible this afternoon in this higher humidity...but
overall...most FWZs will stay dry. Warmer and drier Tuesday as
upper high builds over the CWA. Westerly winds still expected to
pick up Tuesday mid morning along and west of the Laramie Range as
afternoon humidity falls to the upper single digits and low teens.
Fuels reported as still not susceptible to large fire growth...so
fire weather headlines not expected. Similar conditions Wednesday
with low humidity and gusty west winds west.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...GCC
LONG TERM...MB
AVIATION...RUBIN
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Grand Rapids MI
1057 PM EDT Mon Jul 10 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 1057 PM EDT Mon Jul 10 2023
No changes to the going forecast for tonight. A cold front is
situated upstream from the Eastern U.P. southwest into Southern
Minnesota. A band of showers and thunderstorms are located along
the front as of 1050pm. We expect instability to continue to wane
tonight. What will be left late tonight as it moves into Central
Lower Michigan will likely just be scattered showers. The last
two runs of the HREF have shown very meager precipitation in the 3
hourly probability matched mean. So, some scattered pops over
Central Lower looks to be a good forecast. A seasonable night is
in store in a southwest flow, with lows in the 60s.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 218 PM EDT Mon Jul 10 2023
- Risk for showers/storms late tonight into Tuesday
Weak elevated instability shows up along the cold frontal zone
later tonight and into Tuesday. Generally though this instability
will be weakening as the front moves into the CWA. A low level
jet will be accompanying this front but the nose of it will be
located over northern Lower MI which is where the strongest and
greatest coverage will be overnight. Surface based instability
redevelops across the CWA Monday afternoon and several and we
could see redevelopment of the thunderstorms then. Deep layer
shear is shown to be up around 30 knots which could lead to some
organization. SPC HREF shows the best potential for stronger
growth of the storms to be near and east of a Mount Pleasant to
Lansing to Jackson line. Low level wind fields Tuesday afternoon
will be convergent as the front slips through the CWA so low level
lift is expected.
- Possible late night storm Tuesday night
The frontal zone will become nearly stationary near or just south
of Interstate 94 later Tuesday night. Showers and thunderstorms
could start to reform along this boundary towards daybreak as a
possible MCS takes a track southwest of the CWA. SPC HREF trends
also show an increased potential for late night showers/storms for
the southern half of the CWA. We did bump up POPs to reflect
this trend.
.LONG TERM...(Wednesday through Monday)
Issued at 218 PM EDT Mon Jul 10 2023
- Rain Potential Remains for Wednesday
A stationary boundary will be located somewhere near the MI/IN
border by Wednesday morning. The upper level pattern across the
Midwest Wednesday morning will feature a coupled upper level jet,
500 mb shortwave feature, and a 30-40 kt low level jet tapping Gulf
moisture and converging it over a surface stationary front. These
all support the likelihood of MCS development across the Midwest,
which is broadly agreed upon by numerical guidance via modeled
precipitation output.
An MCS should be ongoing Wednesday morning likely across Iowa and
northern Illinois, but there is uncertainty in the geographic
location and extent of this feature, as well as the eventual
propagation during the day and whether it may impact us. A few
scenarios could unfold. One possibility is this complex presses E/SE
and modulates the stationary boundary further south into IL/IN/OH,
leaving the best forcing for either sustainmnent of existing
convection or development of new convection out of our area with
little threat for rain. A second scenario is the complex breaks into
multiple segments...one heading south toward greater instability
during the morning but a second segment developing on the nose of an
increasingly northward oriented LLJ (see 12z GFS/GEM and 00z/06z/12z
ECMWF) that gets into Michigan late morning through the afternoon
and potentially the evening as well. A third scenario, perhaps least
likely, is that the morning MCS gets far enough north to impact us
with additional storm development on the back of it as the LLJ ramps
up. Either the 2nd or 3rd scenario would bring a fairly broad area
of rain with some thunderstorms to the region, and enhanced
potential for rain amounts in excess of 1". At this point the 2nd
scenario is favored but until we get into the 24 hr window for the
CAMs this will be difficult to ascertain with much confidence.
Any threat for severe weather with this system would depend on the
positioning of the stationary boundary, which will mark the northern
extent of surface based instability. We will likely see only
elevated convection, and with thin CAPE shown on model soundings
this will probably come down to whether any strong winds aloft can
mix down to the surface near the boundary.
- Unsettled Weather Possible at Times for Late Week into Weekend
Scattered showers and a few storms may occur Thursday in the wake of
Wednesday`s system mainly east of US 131. With low level W/NW flow
off Lake Michigan it seems unlikely there will be much rain west of
US 131 on Thursday. Beyond Thursday, it appears the Friday
night/Saturday morning timeframe is favored for additional rainfall
as another 500 mb vorticity maximum pivots through and a LLJ may
develop across the Midwest. Truth be told, given the entrenched
positioning of the upper low across northern Manitoba and Ontario
late week into the weekend and occasional vort lobes swinging across
the Great Lakes, periodic showers and thunderstorms are a
possibility through the weekend and into Monday, though breaks will
occur.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 805 PM EDT Mon Jul 10 2023
Despite a cold front sweeping southeastward through the area over
the next 24 hours, VFR weather is still expected to prevail most
of the time. Clear skies are in place at 00z and that will remain
the case at the TAF sites into the overnight hours. It is not
really until the 06z to 09z time frame that some clouds will
filter in from the northwest. That said, these clouds will still
be VFR with bases at or above 5,000 feet.
Clouds will traverse the TAF sites on Tuesday as the front moves
into the area. We expect broken ceilings to develop with bases
around 5,000 feet. The best chance at scattered showers and
possibly an isolated thunderstorm will be at BTL, LAN and JXN in
the 16z to 23z time frame. Chances for thunder were too low to
include in the TAFs, but we have VCSH in at the aforementioned
sites.
Winds will continue from the southwest tonight in the 5 to 15 knot
range, increasing to 10 to 20 knots on Tuesday.
&&
.MARINE...
Issued at 127 PM EDT Mon Jul 10 2023
High res models like the HRRR show the gusty south to southwest winds
persisting overnight over Lake MI as the cold front moves into
the zones. This is also when the low level jet moves in. These
stronger surface winds will build the waves this afternoon and
evening leading to hazardous boating/swim conditions. We decided
to extend the headlines and shift them into Ottawa County.
Commonly, when these fronts move in late at night the waves
remain elevated. The veering winds around the frontal zone will
also help to push the higher waves further south, likely into
Ottawa County. As a result it looks like the conditions to start
Tuesday will feature waves over 3 feet, which can lead to
hazardous conditions.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Tuesday morning for MIZ037-043-
050-056.
LM...Small Craft Advisory until 11 AM EDT Tuesday for LMZ846>849.
&&
$$
UPDATE...Duke
SHORT TERM...MJS
LONG TERM...Hoving
AVIATION...Duke
MARINE...MJS
Area Forecast Discussion
National Weather Service Gray ME
1110 PM EDT Mon Jul 10 2023
.SYNOPSIS...
A frontal boundary will remain stalled over the region through
tonight as an area of low pressure tracks along it. This will
result in numerous showers and drenching thunderstorms with
flash flooding remaining possible, especially across the
interior. Conditions likely won`t dry out until the middle of
the week before conditions potentially turn unsettled again late
week. Otherwise warm and humid conditions will continue.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1110 PM Update... Upper low is now pivoting across western Mass
with a dry slot pushing across the southern half of NH into far
SW Maine. Further north, an arcing band of moderate rain
stretches from northern NH towards the Mid Coast. Latest runs of
hi res guidance brings the band northeastward through the rest of
tonight and clears far northeastern zones by daybreak. The good
news, is that areas hardest hit with rainfall across SW NH
towards the White Mountains will see little if any additional
rainfall for the rest of tonight. The focus for heaviest
rainfall for the rest of tonight will be across the western
mountains and foothills of Maine towards the Canadian Border.
Have mainly fine tuned PoPs and QPF overnight and have removed
chances for thunder as there has been little lightning activity
over recent hours.
650 PM Update... Going forecast is in good shape with a
convective band of showers staying south of New Hampshire as it
slides east across Mass. Main concern in the near term is still
across SW NH in northern Cheshire and Sullivan Counties where
current flood advisories are in effect. Rainfall rates here have
approached and in some cases eclipsed 1 inch per hour. The last
few runs of the HRRR does indicate a drying trend here as
precipitation lifts northeast with rates declining. Also,
previous runs of the HRRR have been highlighting a second band
of heavy rainfall pivoting into western Maine later this evening
as the left exit region of an upper jet nears the area. However,
latest runs of the HRRR and WoFS has suggested this second band
will be weaker than previously advertised. Will continue to
monitor SW NH over the next hours or so for short fused products
with attention then turning towards SE facing slopes of the
Whites towards central Maine.
Previously...
The forecast is going along reasonable well today, as the sfc
low slowLy moves NNE from southern New England to Northern New
England. Dry slot evident over central MA based on radar and
satellite, and convection developing in this area which will
track N into SW NH. Although CAMs disagree on how this holds
together. Otherwise seeing a steady stream rain moving N along
the MA coast into S NH and SW ME, but it seems to lose some of
its punch as it approaches the NH seacoast. Models suggest a E-W
band of convection, probably associated with the occlusion and
close to the triple just to W, developing over the gulf of ME in
a few hours and shifting N onto the SW ME coast, early this
evening. Will have to watch for this feature, as it could
produce good rainfall rates. Probably won`t be an issue for much
of the coast and points just inland, but could be a problem for
the foothills and mountains of western ME, which have been hit
hard from prior flood a week or two ago. IT seems that most of
the heavy precip will be done in the SW NH and CT valley by
02-03Z, and over the western ME by about 06Z or so, but some
linger shower will continue overnight. Low will once again
mainly be in the 60s, but maybe a few degrees cooler than last
night, running from the low to mid 60s mostly.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
An actual cold front will work through the area in the pre-dawn
on Tuesday and winds shift to NW during the morning. Will see
clearing from W-E during the day, with NH seeing some sun in the
morning and ME in the afternoon. Will actually see NW winds,
10-15 mph, which we haven’t seen a while. The ME mountains may
see some showers and clouds will linger until late afternoon.
Highs will range from the mid 70s in the N and and E zones to
the low to mid 80s across the srn half of NH and SW ME. Winds
subside and skies clear out Tuesday night, which will allow some
weak rad cooling, but Tds will still be in the upper 50s N, to
the low 60s, and with wet ground, likely to see patchy fog
developing, with lows mostly in the 60-65 range, but upper 50s
in the mtns.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
High Impact Weather Potential:
* Temperatures reach 90F over southern areas Wednesday with heat
indices 90-95F likely.
* Weak frontal system will bring the potential for a few strong to
severe thunderstorms Wednesday.
* Greatest threat of flash-flood producing rainfall will be on
Friday.
* Shower/thunderstorm chances continue this weekend with the
potential for additional flooding and possibly severe storms.
--Pattern and Summary--
Primary controlling feature through the long term forecast period
remains longwave trough/closed low centered in the vicinity of
Hudson Bay with multiple disturbances rotating around this feature
and into the northeastern United States. This entire closed low will
begin to dive south towards the US/Canadian border by the end of
this forecast period...which will maintain warm....moist
south/southwest flow across the region through next Monday. The
overall result will be a warm and active pattern with each shortwave
impulse focusing concerns on flood potential given saturated soil
conditions while heat will be the focus between the events as
humidity levels remain high.
--Daily Details--
Wednesday - Thursday: Cold front north and west of the region to
open the period Wednesday will stall as mid level forcing pushes off
to the east before flow backs southwesterly Wednesday night into
Thursday ahead of next approaching shortwave. Convective coverage
appears pretty low given relatively weak forcing on Wednesday...
which should allow us to see some sun and take advantage of T8s
around +15C and westerly flow to support 80s to around 90 from north
to south with the westerly flow keeping the seabreeze from making
much inland progress. Will have to watch for a few spots in
southern NH and SW ME nearing heat advisory criteria. Convective
chances into Thursday as the front returns north and shortwave
energy arrives from the west.
Friday: Southerly flow boosts PWATs to near 2" once again with good
deterministic/ensemble agreement in a potent shortwave pushing
through the region in the southwest flow aloft. This will bring the
best chances for more widespread shower/storm activity of the period
and given very wet antecedent conditions...flash flood risk will be
of concern /see WPC ERO Slight Risk for this period/. It is a bit
early to look too deeply into model soundings...but airmass supports
deep warm cloud depths and...depending on the timing of the arriving
shortwave...the potential for significant instability. With the
precipitation activity...highs look at least 5-7F cooler than on
Thursday though dewpoints will keep it feeling tropical.
Saturday - Sunday: Broad southwest flow continues across the region
through the weekend. Timing embedded impulses in the flow is not
possible at this range though the GFS/GEFS has a deeper upper low a
bit to the New England which provides more support for diurnal
convection over the weekend. A continued humid airmass supports
warm overnight lows with seasonable highs in the upper 70s to lower
80s. Mid level flow looks modest which indicates that along with a
continued isolated flash flood risk...there will be a risk for
isolated severe thunderstorms as well.
Monday: Consensus guidance trends PoPs down a bit on Monday with
less signal for any upstream shortwaves with the longwave trough
axis over the Great Lakes. High temperatures remain seasonably mild
with the streak of warm overnight lows continuing with dewpoints
well above 60.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Short Term...One more night of widespread IFR-LIFR in fog and
low clouds as the system moves out Tuesday morning and winds
shift to NW. MAy take a chunk of of the morning to clear along
the coast and at KAUG, but should see VFR there by midday.
Given the very wet ground, will likely see ground fog
developing, so fog is a good possibility at any terminal, but
especially KHIE/KLEB.
Long Term...Mainly VFR expected Tuesday night through Thursday,
but will have to watch for the potential for nighttime stratus
and fog to come back into the picture by Thursday night. Lower
conditions expected Friday with the arrival of showers.
&&
.MARINE...
Short Term...Will see the Se winds gust around 20 kts ahead of
cold this evening and overnight, but winds shift NW on Tuesday
and stay below SCA levels through Tue night. Also will get a
break from the fog by Tuesday afternoon.
Long Term...Conditions to remain below SCA through Friday.
&&
.HYDROLOGY...
WE have to get through the evening before the threat of heavy
rains lessens, but expecting it to start to dry overnight, and
definitely on Tuesday. Some river may remain above flood through
Tuesday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch until 8 AM EDT Tuesday for MEZ007-008-012-013-033.
NH...Flood Watch until 8 AM EDT Tuesday for NHZ001>009-011-015.
MARINE...None.
&&
$$
UPDATE...Schroeter
NEAR TERM...Cempa
SHORT TERM...Cempa
LONG TERM...Arnott
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
632 PM CDT Mon Jul 10 2023
.SHORT TERM...
Issued at 208 PM CDT Mon Jul 10 2023
Through Mid-Day Tuesday...
As higher pressure moves eastward over southern Illinois toward the
Tennessee Valley, the impact to Chicagoland is a fairly gorgeous day
with blue skies that is being jealously observed on local webcams.
Temperatures took a little longer to rise compared to what was
forecast so high temperatures were adjusted down by a couple
degrees; however mid to upper 80s are still projected for Monday.
Winds will remain breezy, 10 to 15 mph, out of the southwest,
through early this evening for a nice mid July evening.
An area of showers and some thunderstorms sitting over Northern
Wisconsin as of this writing is associated with a cold front.
Additional showers and thunderstorms, some strong to severe, are
expected to initiate off the front over the Upper MS Valley and
then propagate southeastward through tonight. Given an
increasingly hostile environment for convective maintenance
locally, the approaching convection should be a rapid decaying
trend as they draw nearer. That said, trends will be monitored
through the night as again, decaying showers and storms are
expected to move southward, but not projected to cause notable
thunderstorm impacts into northern Illinois into Tuesday morning.
Mostly clear to partly cloudy skies are otherwise projected with
Tuesday morning low temperatures in the low 60s farther inland,
with upper 60s in the city.
DK/Castro
Through Wednesday Night...
Key Forecast Messages:
* Scattered thunderstorms Tuesday afternoon and early evening
along a south and southwestward advancing cold front, a few of
which may be severe with a hail and wind threat
* Potential for training thunderstorms and a flash flood threat
Tuesday night into Wednesday morning
* Additional threat for severe weather during the day on Wednesday
into the evening, particularly south of I-80, with damaging
winds the main threat
The backdoor cold front, moving more quickly down the lake and
then advancing south and southwestward with time, will be the
source of lift for convective initiation Tuesday afternoon via
enhanced lower level convergence. This is due to gradually rising
500 mb heights and stronger large scale forcing with a potent
short-wave trough passing well to our northeast. There is
uncertainty regarding overall thunderstorm coverage given timing
differences in the front surging southward and owing to the lack
of stronger large scale forcing, plus a pocket of dry mid-level
air advecting southeastward in concert with the front. However,
that said, signal in a broad sense remains robust enough for
scattered afternoon thunderstorm mention in the grids.
Temperatures in the mid and upper 80s ahead of the cold front and
dew points pooling in the mid-upper 60s (locally 70F) ahead of it
will provide the fuel for 1000 to up to 2000 J/kg of MLCAPE with
little/no capping amidst relatively steep (~6.5C/km mid-level
lapse rates). 25-40 of 0-6 km bulk shearing and good veering with
height in sharp northwest flow aloft could yield a couple
supercells with an attendant hail and wind threat. SPC`s level 1
of 5 (marginal) risk in their day 2 outlook appears reasonable for
this setup. Temperatures cooling fairly quickly near the lake
behind the front during the afternoon is one more item of note for
tomorrow.
Conceptually, the lack of stronger forcing as 500 mb height rises
continue through the evening suggests that Tuesday PM convection
will have a strong diurnal component with coverage in the vicinity
of the front (by then near the I-80 corridor or a bit south)
diminishing fairly quickly in the evening. This relative break may
be short-lived however though into the later evening and
especially overnight.
Concern is increasing for a frontal type Maddox flash flooding
threat in a corridor just north of the front. Gradually
strengthening LLJ will focus moisture transport near the stalling
cold frontal boundary, with 65+F dew points moving back northward.
The frontal position should generally be south of I-88 in our
timeframe of greatest concern, oriented from west-northwest to
east-southeast. Given northwesterly 500 mb flow regime roughly
paralleling the frontal orientation, this scenario may yield
upwind propagation of convective cells near the boundary. By this
time, ensemble mean dew points up to 1.8" will be more than enough
for an appreciable heavy rain threat, and an increased threat for
flash flooding if training occurs.
This potential would continue into Wednesday morning and the
frontal position being reinforced by convection relatively farther
southward may very well play a role in what happens the rest of
Wednesday, discussed in next paragraph. Timing and location wise
for this heavy rain and flash flooding threat, note that the most
recent extended HRRR runs have been farther northward and earlier
than other operational and CAM solutions, something to keep an eye
on. However, grids for now are a lean toward the later and I-88
and south corridor, if not south of that, being in a more favored
zone per consensus frontal boundary position. WPC has a level 1
of 4 (marginal) risk in their day 2 ERO, up to a slight (2 of 4)
in the updated day 3 ERO, which capture things fairly well for now.
Turning to the threat for severe weather on Wednesday, with 40-50+
kt northwesterly 500 mb flow, an ingredient is there for a robust
forward propagating and wind producing MCS, if one gets going,
which would be favored to occur during the day for locales south
of I-80, including our central IL and northwest Indiana to the
south of the Kankakee River. Overall confidence in convective
evolution trends on Wednesday is unfortunately on the lower side.
Should the juicy air mass featuring 70+F dew points be able to
advance back northward (if a strong MCS and cold pool doesn`t
occur), then the parameter space may become favorable for severe
storms farther north. Unfortunately, Wednesday is one of those
days where a lot will be learned observationally over the next
36-hours that will help ascertain the general trends. Until that
point, we`re unable to offer much in the way of specifics.
Signal is strong for waves of showers and storms regardless of
severe and flood threat evolution, so categorical NBM PoPs were
maintained. Temperatures are favored to be a bit below normal in
the 70s to around 80F due to the clouds and precip.
Castro
&&
.LONG TERM...
Issued at 330 PM CDT Mon Jul 10 2023
Thursday through Wednesday Night...
As we get to Thursday, the two drivers for our weather will be
the Canadian low-pressure system centered over Hudson Bay, and
another low centered over the Northern Pacific. These will
continue to influence a ridge over parts of the continental United
States, and will create hit or miss chances for precipitation.
Looking at the 500mb isotachs, the jet stream will continue to
track along the ridge, and due to this going right over our area,
on and off showers and storms will be possible late in the week
into the weekend. During this period, temperatures will be
consistently in the lower to mid 80s, and dew points in the 60s to
near 70, before drier air advects southward later on Sunday.
Currently, the Canadian low is centered over Northern Ontario,
and as the days progress, it will cycle around and start to swing
back south. When the low reaches its southern peak on Sunday, the
upper level ridge would sink to our south, which results in our
area underneath an upper level trough. Counterclockwise flow will
likely advect a wind from the northwest, which will help keep
higher temperatures, dew points, and other ingredients favorable
for rain to the south, and would limit precipitation chances by
the end of the weekend. Exact timing of this switch is difficult
to say because if it was to slow down, we may not see that until
early to mid next week. But before the upper low comes closer to
our area, expect humid temperatures, and on and off rain chances.
Bjork
&&
.AVIATION...
For the 00Z TAFs...
Aviation weather concerns through Tuesday evening consist of:
* Potential for TS late tonight, mainly INVOF RFD.
* Sharp NE wind shift Tuesday afternoon at the Chicago-area
terminals with a cold front.
* Second potential for scattered showers and thunderstorms Tuesday
afternoon and evening.
Southwest winds will ease under 10 kts tonight with VFR conditions
at all terminals. Thunderstorms are currently developing upstream
across northern Iowa and southern Minnesota and there is some
potential these meander into northern Illinois overnight tonight.
Have introduced a PROB30 at RFD to account for this increasing
potential, but have refrained from a mention at the Chicago-area
terminals where this potential looks a bit too low to justify a
formal inclusion.
A sharp northeast wind shift will occur on Tuesday afternoon with
a cold front. Have not made any changes to the inherited timing
from the previous TAFs (approximately 20z at ORD, MDW, and GYY,
and about two hours later at DPA). Scattered showers and
thunderstorms may develop along this boundary. While confidence is
increasing that TS will develop in/around c90, it`s not high
enough at this time to warrant TEMPO groups or a VCTS mention at
the terminals at this time.
Additional bouts of showers and storms are possible just beyond
the current extended ORD/MDW TAF windows.
Carlaw
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
Visit us at weather.gov/chicago
Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSChicago
www.twitter.com/NWSChicago
www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Marquette MI
913 PM EDT Mon Jul 10 2023
.SHORT TERM...(Through early afternoon)
Issued at 1114 AM EDT MON JUL 10 2023
Morning showers associated with the initial push of a cold front
moving into the region have exited Upper Michigan. This supported
some isolated shower activity over mostly the south and east this
morning, with a few embedded thunderstorms observed as well.
Following this, low level clouds pressed eastward just ahead of the
analyzed cold front and worked to establish a north-south
temperature gradient over the forecast area as the front took on a
more west-east orientation. Current placement of the front is that
it extends eastward from near Lake o` Lakes across the central.
North of the boundary, temps have been largely steady in the low 70s
or upper 60s but south of the boundary, temps have warmed into the
mid 70s with dewpoints in the low-mid 60s. Along and south of the
boundary, current mesoanalysis paints a corridor of increasing
instability and should be the main focus for afternoon/evening
convection late today.
.LONG TERM...(Late Afternoon through Monday)
Issued at 328 PM EDT MON JUL 10 2023
An active and seasonably cool pattern is expected to prevail
throughout the long-term as an upper level low parks across the
Manitoba-Ontario-Hudson Bay region. Shortwaves rotating around the
closed low about every other day result in frequent rain chances and
near to above normal precip through the extended period. The most
energetic/amplified shortwave pivots southeast across the area late
this afternoon into early tonight. A noticeably cooler and drier
air mass moves in behind tonights cold front with clearing skies
leading to some fog potential, especially where it rains this
evening. The next chance for more widespread showers/storms
appears to be Friday into Saturday , but there could be a few
isolated showers during the aftn/evening Wednesday and Thursday
too.
Confidence is high that thunderstorms will develop in the vicinity
of a cold front later this afternoon and evening as an intense PV
maxima digs southeast toward the UP. Surface observations and the
17Z RAP mesoanalysis indicates that frontal boundary is currently
positioned near the line from Land o` Lakes, WI east to Trenary, MI
north-northeast to Wawa, Ontario. A lake-breeze enhanced cold front
showed up on radar around 1630Z and surged south across Alger County
where it intersected a shower that developed over northern WI late
this morning. RAP model soundings indicate in this area show ~1000
J/kg MLCAPE and effective shear of 35-40 knots that is sufficient
for organized updrafts, but so far updrafts continue to struggled
reach the modeled equilibrium level (though the storm passing south
of Iron Mountain at 19Z seems to be tapping into better CAPE). The
majority of available shear is below 3km with uniform westerly flow
from there up to the equilibrium level suggesting more surface-
based, pre-frontal storms have the best severe potential. Thus, this
threat is mainly confined to the triangle Iron Mountain to Escanaba
to Marinette.
Looking ahead through this evening, HREF guidance shows thunderstorm
probabilities increasing from ~30% at 21z to ~90% at 01Z as the 850
mb LLJ ramps up to near or above 30 knots. Additional convergence at
the nose of this feature is likely to result in more widespread
thunderstorm development. Model soundings by 02Z show a stable
boundary layer with weak to moderate elevated instability rooted
near 850 mb and cloud layer bulk shear near or below 20 knots.
Overall, this suggests poorly organized storms along and north of
the cool front and given the cooler environment there could be some
small hail potential with the strongest storms. The other aspect to
monitor is related to heavy rainfall potential as a narrow axis of
fairly impressive f-gen forcing intensifies with the LLJ this
evening. Event-total probability matched means seem to have
decreased a bit, but still indicate a narrow axis where training
thunderstorms are possible this evening. The latest guidance
suggests this axis will extend roughly between Iron Mountain and
Munising.
Rapid post-frontal drying/clearing results in clearing skies from NW
to SE tonight that when combined with earlier rainfall could allow
for patchy fog formation. While the 12z 3km NAM is likely too
aggressive with nocturnal cooling, it deserves an honorable mention
for dipping lows into the mid-30s across the typical cool spots of
the interior west. The next shortwave moves into the area on
Wednesday, but dry low levels suggests it will struggle to squeeze
and precip out of the increasing cloud cover. If rain occurs on Wed,
the best chance appears to be near the WI state line. Somewhat more
moisture in place for Thursday could allow for diurnal shower
activity, but a better chance for rain arrives on Friday as another
cold front pushes across the UP. A reinforcing cool front could
wring out of lighter showers on Saturday before the next dry air
mass moves in for Sunday/Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 913 PM EDT MON JUL 10 2023
A cold front will continue pressing southeastward through the region
into tonight, continuing to kick up showers and stronger
thunderstorms along the boundary; severe storms are no longer
expected to impact the TAF sites. These showers and storms could
produce heavy rain that may periodically reduce visibilities and
ceilings at SAW through the next 1 to 2 hours. As this boundary
continues away from the region, expect clearings skies overnight and
a return to VFR conditions.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 328 PM EDT MON JUL 10 2023
A cold front pushed across the lake today with generally light and
variable winds late this afternoon. Northwesterly winds overspread
the lake by Tuesday morning but will remain light and below 20 knots
through next weekend. Showers and thunderstorms will be likely
especially across the southeast half of the Lake from late this
afternoon through this evening.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JTP
LONG TERM...EK
AVIATION...Jablonski
MARINE...EK
Area Forecast Discussion
National Weather Service Great Falls MT
839 PM MDT Mon Jul 10 2023
.SYNOPSIS...
After a few showers and thunderstorms this evening, slightly
cooler air will arrive across North Central and Southwestern
Montana, keeping highs in the 70s and 80s the next few days. In
addition to the cooler temperatures, tranquil weather is also
expected, with only a few isolated thunderstorms after midweek.
&&
.Update...
Evening update has been published, with the primary change being
to increase PoPs across eastern portions of Central and North
Central Montana. Numerous showers and thunderstorms were moving to
the northeast of a Lewistown to Whitlash line as of 2030 MDT,
with isolated to scattered showers and thunderstorms behind the
main line across western portions of Southwest through North
Central Montana. As the evening progresses, expect the primary
line of showers and storms to exit to the east over the next
1-2hours, with the remaining isolated to scattered showers and
thunderstorms slowly dissipating and/or lifting northeast and out
of the CWA through 0300 MDT to 0600 MDT Tuesday. While a few
strong wind gusts of between 45-55 mph can`t be ruled out over
portions of Fergus, Blaine, and Hill counties over the next 1-2
hours, the threat for severe thunderstorms continues to decrease
with the loss of surface heating and instability. Otherwise, the main
concern through the remainder of the night and into Tuesday
morning will be the threat for fog development, especially in the
valleys of Southwest and Central Montana, where rain recently fell
as skies slowly clear from west to east through sunrise on
Tuesday. - Moldan
&&
.AVIATION...
408 PM MDT Mon Jul 10 2023 (11/00Z TAF Period)
Showers and thunderstorms will continue to move to the northeast
through the remainder of the afternoon and evening, clearing the
KCTB, KGTF, KLWT, KHLN, KBZN, and KEKS terminals between 03z to 06z
this evening and the KHVR terminal between 05z to 08z Tuesday. Main
threats from any of the stronger thunderstorms will be frequent
cloud to ground lightning, gusty and erratic winds up to 30kts, and
the possibility for hail. While CIGS are largely expected to remain
VFR throughout the 1100/1200 TAF period, brief but intense bursts of
heavy rain could lead to MVFR/low-VFR CIGS and/or VIS. Periods of
mountain obscuration will occur through 06-12z Tuesday, with
improving mountain visibility expected thereafter. - Moldan
Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.
&&
.PREV DISCUSSION...
/ISSUED 408 PM MDT Mon Jul 10 2023/
A potent shortwave trough extending from Eastern Washington
through Idaho will lift through the area this afternoon, sparking
off numerous showers and thunderstorms. Earlier forecasts, and
still this one to a degree, were keying in on the potential for
strong to possibly severe thunderstorms across the area, but some
early morning cloud cover across Central and Southwestern Montana
helped to keep temperatures a bit cooler than expected across
parts of the area, which in turn kept the atmosphere a bit more
stable. Now that the cloud cover has begun to thin out,
temperatures are starting to recover, but it remains to be seen if
the area will still destabilize in the way it was expected to.
In spite of the morning clouds, we are still seeing some
convective initiation along the Rocky Mountain Front and along the
Montana/Idaho border, so the storms are there. The main question
is whether or not the environment is still favorable for the
storms to develop organized cold pools (which will drive the
winds). To this effect, the 18z/noon run of the HRRR shows a less
organized cold pool than it did earlier in the day, and the SPC
mesoanalysis show some capping (which could hinder storm
development), so I am less concerned about severe winds than I was
24 hours ago. Regardless, I do still expect the thunderstorms to
produce some gusty outflows as they propagate northeastward this
afternoon and evening, and while it could still reach severe
criteria (58 mph winds), it looks less likely than it did before.
For now, the area most likely to see strong winds will largely be
an area between I-90 and the Montana/Idaho border, where downdraft
potential is highest at this time.
Beyond tonight, our weather will turn a bit cooler and more
tranquil as the upper level flow becomes more zonal (westerly).
Aside from a few leftover rain showers Tuesday morning, dry
weather is expected Tuesday and Wednesday as weak surface high
pressure builds into the area. A slightly better chance for rain
will arrive Thursday and Friday as another shortwave trough pushes
through, but this system will very limited moisture to work with,
which will result in just a few isolated showers and thunderstorms
as the trough slides by.
Looking towards the weekend, upper level ridging will begin to
build across the Western CONUS. This will allow for rather
tranquil conditions as temperatures warm over the weekend, with
highs likely returning to the upper 80s/low 90s by next Monday.
Ludwig
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 82 52 85 / 50 10 0 0
CTB 52 77 49 82 / 50 20 0 10
HLN 58 85 54 88 / 70 0 0 0
BZN 53 84 49 84 / 70 0 0 0
WYS 44 76 39 77 / 30 0 0 0
DLN 50 81 46 82 / 40 0 0 0
HVR 59 84 55 84 / 80 30 10 10
LWT 55 80 51 80 / 80 10 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls