Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/03/21
Area Forecast Discussion
National Weather Service Cheyenne WY
514 PM MDT Fri Jul 2 2021
.SHORT TERM...(This evening through Monday night)
Issued at 212 PM MDT Fri Jul 2 2021
Forecast concerns deal with shower/thunderstorm chances through
the short term. Currently...still have a stationary boundary over
the eastern half of our CWFA this afternoon. Dewpoints in the
upper 50s east of this front across the Nebraska Panhandle and low
50s across the southeast Wyoming plains east of the Laramie
Range. While west of the front...we are seeing upper 30s and low
40s across Carbon County. Radar beginning to show some showers and
thunderstorms developing across northern Colorado.
For this afternoon...looking at afternoon surface based CAPE on
the order of 1500/2000 J/KG with afternoon heating. Sfc-6km shear
still not all that impressive around 20-30kts. So not expecting
much in the way of severe thunderstorms. Forecast storm motions
still low...under 15kts...especially out in the panhandle. So
could see some heavy rainers once again today. Latest HRRR shows
convection peaking out around 22Z to 01Z...then dying off quickly
with less heating.
SPC has a Marginal Risk for severe thunderstorms in the Nebraska
Panhandle for Saturday. A little bit better directional shear as
upper level winds out of the northwest and low level winds out of
the southeast. Still not all that impressive...but a few storms
could be severe Saturday afternoon.
Clipper system Sunday moves through the eastern CWFA that could
give us another good chance for more widespread convection into
Monday afternoon.
.LONG TERM...(Tuesday through Friday)
Issued at 212 PM MDT Fri Jul 2 2021
Tuesday...Somewhat similar coverage to Monday with scattered showers
and thunderstorms during the afternoon under northwest flow aloft. A
bit cooler with the coverage of showers and thunderstorms.
Wednesday-Friday...Ridging aloft builds overhead, and with the
warmer temperatures aloft, more limited shower and thunderstorm
coverage is anticipated, isolated at best. Warmer temperatures also
expected with the forecasted 700 mb temperature rise. Perhaps
slightly cooler on Friday with a bit more cloud cover.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 506 PM MDT Fri Jul 2 2021
VFR conditions and SCT cloud cover bases around 8-10k ft continue
for all sites across southeastern Wyoming and western Nebraska
Panhandle. Isolated thunderstorms will push eastward until 10PM
bringing VCTS at sites KLAR and KCYS until 04Z. Gusty winds up to
30kts will arrive in the Nebraska Panhandle starting 15Z for all
sites until Saturday evening 00Z.
&&
.FIRE WEATHER...
Issued at 212 PM MDT Fri Jul 2 2021
Minimal fire weather concerns as we see daily chances for showers
and thunderstorms through at least Tuesday. Afternoon humidity
remains above critical levels with good overnight recoveries.
Weather forecast to change after Tuesday as high pressure builds
back into the area with drier weather and lower humidity. By
Thursday and Friday next week...southwest winds forecast to become
breezy with afternoon gusts over 30 mph. So looking at possible
critical fire weather conditions at that time.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...GCC
LONG TERM...RUBIN
AVIATION...AW
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
257 PM PDT Fri Jul 2 2021
.SYNOPSIS...Hot and dry weather will persist across the interior
through this weekend and into early next week. Coastal areas will
remain seasonably cool with nightly stratus intrusion into the
coastal river valleys, followed by some afternoon clearing.
&&
.DISCUSSION...Hot and dry conditions will persist across the interior
through next week as a warm and dry air mass dominates. Valleys
in Trinity and far NE Humboldt Counties will be the hottest this
weekend with highs around 98-104F degrees. Elsewhere in the
interior, afternoon high temperatures will generally range from
the mid 80s to upper 90s. The heat risk will remain mostly in the
moderate category through this weekend, but there will be
localized areas of high risk in Trinity County such as Big Bar.
While temperatures are above average, current guidance does not
warrant the issuance of a heat advisory. Stratus has remained
locked onto the coast and offshore for the last several days.
Nightly stratus intrusion into the North Coast river valleys
(mainly the Eel and Van Duzen) is expected through the weekend. A
southerly wind reversal is also expected to develop this weekend.
Southerly winds may advect Sonoma County stratus into the southern
Mendocino interior (Hopland and Ukiah) during the early morning
hours Saturday and Sunday.
Confidence we will see any thunderstorms over or nearby northeastern
Trinity County this weekend continues to fade. SREF plumes indicate
sufficient mean MLCAPE for thunderstorms each day. The atmosphere
is quite dry, but PWATS do appear to increase some on Saturday.
BUFKIT profiles actually have CAPE peaking in the late evening
on Saturday, however air parcels will need to be lifted from
12,000 to 13,000 feet for the CAPE to be released. Convective
allowing models continue to indicate high probabilities for deep
convection and thunderstorm/lightning activity over the Sierra
Nevada and NE California. Granted the HRW-NSSL indicates composite
reflectivity less than 40 dBZ near far NE Trinity County late
Saturday afternoon. Thus expected some afternoon cumulus build
ups. There is a disturbance that is forecast to rotate northward
around the four corners ridge Saturday. NAM-nest hint at returns
aloft drifting over Lake and southern Mendocino Counties Saturday
night. HREF probabilities for thunderstorms remain well to the
east and southeast of the area during this time period. Thus, will
leave out any mention of nocturnal storms.
Hot/dry weather is expected to persist in the interior, while
coastal areas have cooler temperatures with persistent marine
layer cloud cover through next week. A trough will approach early
to mid next week and may bring some interior cooling. The four
corners ridge will likely expand westward/northwestward toward
the end of the week bringing another round of triple digit heat to
the interior. The rate and magnitude of this next warm up are
highly uncertain at this time.
Also of note, smoke from the Salt fire north of Redding along the
I-5 corridor may spread into eastern and northeastern Trinty
County again tonight. The BlueSky smoke dispersion model shows
some smoke entering Trinity County. This may be a regular
occurrence for the next several days as winds become southeast
and easterly in the morning hours. So far the air quality has
been good to moderate, based on the air quality sensors in NE
Trinity. Air quality has been much worse in Siskiyou County.
Mostly southerly winds should keep smoke from the Lava fire in
Siskiyou county further to our north.
&&
.AVIATION...Stratus blankets most of the coastal waters once again
today. Earlier clouds near the coast were a bit more cumuliform in
nature, with thin spots in between the denser cloud elements. This
has allowed for a bit more clearing along the coast than on
Thursday, although several small eddies in the low-level flow
continue to push clouds inland along the immediate coast (including
at KCEC and KACV). In addition, the Eel River Delta continues to be
socked in. Expect clouds to once again expand inland overnight, with
visibility reductions in fog expected as well. The HRRR model
depicts low clouds advecting N up the Russian River Valley late
tonight. It also indicates a light southerly surface flow into the
early morning hours. This may allow at least a low scattered deck to
make it to KUKI around sunrise. Later shifts will continue to
monitor. /SEC
&&
.MARINE...Advisory-level northerly winds continue across most of the
outer waters this afternoon, with locally gusty winds near and just
S of Cape Mendocino as well. Expect the strongest winds to shift
slightly farther offshore over the next 12 to 24 hours as the max
pressure gradient pivots a bit farther to the W. For this
afternoon`s package, have extended the Small Craft Advisory for the
N inner waters through early Saturday morning due to seas. Have also
extended the outer waters advisory through Sunday night. Winds will
likely drop below advisory criteria in the S outer waters, but
enough of the zone will continue with elevated seas to warrant the
extension. The NW portion of the N outer waters will see near
Hazardous Seas Warning criteria seas into early Sunday, but the
areal coverage doesn`t warrant a warning at this time. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 9 AM PDT Saturday for PZZ450.
Small Craft Advisory until midnight PDT Sunday night for PZZ470-475.
&&
$$
Visit us at https://www.weather.gov/eureka
Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka
For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Area Forecast Discussion
National Weather Service Flagstaff AZ
841 PM MST Fri Jul 2 2021
.SYNOPSIS...Scattered shower and thunderstorm activity will
continue each afternoon through the weekend. Expect a decrease in
storm activity and an increase in temperatures heading into next
week.
&&
.DISCUSSION...Weak convection this afternoon has transitioned to
light stratiform precipitation across southern Navajo and Apache
counties this evening. Otherwise, the remainder of the area is
fairly quiet.
The moisture profile will remain fairly similar on Saturday with
the deeper moisture situated south of Interstate 40. Latest runs
of the HRRR indicate the potential for storms firing off the
Mogollon Rim and pushing into Yavapai County and central Arizona
through the afternoon and evening hours. The stronger storms will
remain capable of producing locally heavy rainfall, gusty outflow
winds, and lightning.
The current forecast handles all of this well and no major updates
are needed this evening.
&&
.PREV DISCUSSION /355 PM MST/...Debris cloud from overnight
convection to the south of the CWA suppressed convection in
central Arizona this afternoon. Areas outside this cloud cover
have been fairly active, with an outflow moving off the White
Mtns zone and into northern Gila county this afternoon. Activity
is expected to consolidate south of the CWA again this evening,
sending larger-scale outflows back northward overnight, This
pattern repeats over the weekend, with deeper moisture south of
the I-40 corridor keeping storms active and only isolated
activity north of the I-40 corridor.
After this weekend, the ridge begins to shift to a less favorable
position and we will partially transition to another heat wave,
with diminished shower and thunderstorm activity.
&&
.AVIATION...For the 06Z package...Mainly VFR conditions will
continue. Expect another round of isolated to scattered showers
and storms Saturday afternoon. Localized MVFR conditions will be
possible in the stronger storms especially along and south of a
KGCN-KFLG-KSJN line. Outside of storm activity, winds will be west
to southwest at 5-15 kts during the daytime hours. Storm coverage
and intensity diminishes Saturday evening. Aviation discussion
not updated for TAF amendments.
&&
.FIRE WEATHER...Afternoon showers and thunderstorms will continue
through Sunday, especially south of the I-40 corridor. Activity to
remain more isolated north of the I-40 corridor. Locally heavy
rainfall, gusty outflow winds, and lightning are the primary
hazards. Generally light winds are expected.
Monday through Wednesday...Expect a slight decrease in convective
activity, with drier air over the northern and west-central zones.
Daytime temperatures will increase during this period. Winds
remaining generally light.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...Excessive Heat Warning from
noon Saturday to 6 PM MST Friday FOR AZZ006.
&&
$$
PUBLIC...TPS/Peterson
AVIATION...TPS
FIRE WEATHER...Peterson
For Northern Arizona weather information visit
weather.gov/flagstaff
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
645 PM CDT Fri Jul 2 2021
.DISCUSSION...(This evening through Friday)
Issued at 355 PM CDT Fri Jul 2 2021
The main concerns revolve around tstm chances/timing and warm
temps through Monday, then better chances for tstms along a cold
front late Monday into Tuesday.
Picture-perfect summer weather is in place this afternoon with
mostly sunny skies, temps in the 80s, and relatively low dew
points for this time of year in the 50s to low 60s. Wind is fairly
light out of the SE. Latest water vapor imagery shows highly
amplified pattern across North America with deep trough over the
NE CONUS, strong ridging through central/northern Plains, then
another trough over the Pac NW/British Columbia. An axis of sfc
high pressure runs from the TX/OK Panhandles NE through the Great
Lakes, which is keeping relatively dry/continental air mass in
place across the Central Plains, with what moisture we do have
likely due to evapotranspiration from rapidly growing corn. Return
flow has setup over MT and W Dakotas, with temps in the 90s to
near 100F, which is a sign of what`s to come our way through the
4th of July holiday weekend and into early next week.
Quiet and relatively comfortable conditions will continue tonight
and through the late evening hours on Saturday. Do not expect any
natural fireworks to impact local festivities through late Sat
eve. It will be a touch more humid and warmer, but still not too
bad for early July with high temps in the upper 80s to near 90 and
Tds in the low 60s. Near and after midnight Sat night, some
tstms that initially develop across the Sandhills may try to
approach far NW/W portions of the CWA (from around ODX to LXN),
but they are forecast to weaken as they do so. Hi-res guidance is
in good agreement that what little activity our area may see will
be late and remain NW of the Tri-Cities, and given the LLJ is
fairly weak and already veered by the time it makes it in, leads
me to believe this is a reasonable scenario.
For the 4th of July (Sun), expect noticeably warmer and more humid
conditions as peak aftn heat indices will likely climb into the
mid to upper 90s. However, a caveat to this is the potential for
one or two MCVs and/or outflow boundaries from Sat night`s
convection to linger in the area, which could spark new convection
theoretically at any time on Sun, but particularly during the
aftn and eve. The 18Z HRRR and 12Z EC depict this scenario the
most, but the 12Z/18Z NAM runs also hint at some sporadic QPF in
or near the CWA at various points in the day. I think the main
takeaway at this point is that there`s a non-zero chc for
shwrs/tstms on Sun the 4th, but I doubt any activity will be
widespread or be considered a "washout". By no means need to
cancel any plans, but be aware that at least a few tstms are poss.
Considerably higher chcs for tstms will arrive at some point early
next week, most likely in the Mon night to Tue time frame, as a
series of upper disturbances flatten the upper ridge and move
through in the zonal/NW flow. This will help drive a cold front
into the region, either Mon night or Tue, depending on the current
model guidance. This is by far the best chc for pcpn with this
forecast package as portions of the CWA are now up to "likely"
PoPs in the latest NBM blend. Ahead of the front, however, will
still be quite warm as Mon is shaping up to be the hottest day
with highs in the mid 90s. Combine this with upper 60s/near 70F
Tds could result in heat indices on either side of triple digits.
Tue should be noticeably cooler owing to increased Nrly flow and
cloud cover/pcpn, with more pleasant 80s also lingering into Wed.
Models hint at a warm-up ahead of yet another cold front at some
point late next week, but they differ on timing, so confidence on
details is low.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 640 PM CDT Fri Jul 2 2021
No big overarching issues for this forecast. There is a small
possibility of a few pockets of MVFR visibility late overnight if
wind winds up subsiding enough and enough moisture from evapo-
transpiration from the height of corn growing season occurs.
Also, wind speed may increase a bit more for Saturday afternoon
and a few CU may develop along with some cirrus.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Thies
AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1053 PM EDT Fri Jul 2 2021
.SYNOPSIS...
A passing cold front will move southeast of the area this evening.
This will begin a dry and mild weather pattern that will last into
the early part of next week. This will give somewhat unseasonal
dryness and fair weather for the Independence Day holiday. By the
mid to late next week, either remnants of Elsa, should there be any,
or impacts from next upstream low pressure system will return
humidity and chances for showers to the forecast.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 950 pm EDT: The persistent HRRR forecasts of the past
several hours showing resurgent convection mainly near and southeast
of I-85 are finally coming to fruition late this evening. SBCAPE
values remain 1000 to 1500 J/kg and forcing from the boundary
settling southeast along with weak H5 DPVA triggering aloft is
allowing more solid scattered coverage to develop. This should
propagate southeast before ending in the lower Piedmont 04Z to 06Z.
Can`t rule out a few strong wind gusts with the stronger storms over
the next couple of hours. Some training has been occurring, but the
activity should be on the move late this evening into the early
overnight and flooding is not expected. High clouds will pull east
overnight, but patchy stratocumulus could linger over the region
with a weak mid-level inversion evident in model profiles. Cooling
temperatures remain on track given the weak cold advection in
developing northerly flow, moderated a bit by modest mixing and the
lingering stratocu. This will produce minimum temperatures about
five degrees or so below normal.
Saturday looks sunny, dry, and not as warm as recent days as high
pressure builds in from the NW under a deep NW flow. Temps should
stay below normal, and dewpoints have been dried out slightly with
mixing in the latest update.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 2pm EDT Friday: Weather should be excellent for the
Independence Day Holiday with relatively low dewpoints for this time
of year yielding a low 5 or so degrees below seasonal normal, and a
high near normal under clear skies. Winds will also be light and
northerly. Weather remains dry through Monday, at least. Post
frontal regime behind trough that pulled a cold front through on
Friday, transitions to a ridge on Monday, continuing clear skies and
warming things up to above normal levels Sunday and Monday. Surface
high will also allow some moisture to begin to move back into the
area on weak southeasterly to southwesterly flow, which along with
evapo-transpiration, will increase humidity late Sunday and beyond.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 2pm EDT Friday: Unclear on the destiny of Elsa, with various
models having quite a variety of possibilities. Latest GFS now de-
amplifies Elsa as it passes Cuba, much like the EC model has been
doing. Approach of Elsa is simultaneous with the eastward migration
of next upstream upper trough. Either of these entities will
increase the chances for rain mid-week, with POPs first rising above
negligible levels Tuesday evening, and in an uptrend each day
thereafter, with higher levels in the afternoon in a typical diurnal
thunderstorm pattern. Mid-level winds peak in the latest GFS
solution at only 20kts Thursday afternoon, which combine with weak
to moderate CAPE to produce only low-end severe chances. Currently
do not have a lot of QPF in the forecast with 1 to 2 inches total
for the Wed through Thu period, but should Elsa hold together and
target the Carolinas, QPF would increase.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Convection has finally started developing
along the boundary settling southeast of I-85 this evening, with
VCSH around the Upstate TAF sites and KCLT, and tempo TSRA indicated
at KAND through 03Z. Otherwise, expect northerly winds to gradually
develop throughout, with steady clearing. Patchy VFR stratocumulus
could linger under a mid-level inversion tonight, but with no
restrictions. Little more than a few high clouds and mainly light N
to NNE winds looks likely through Saturday. KAND winds may toggle
light/variable or back to WSW late Saturday.
Outlook: Dry weather and high pressure will continue into early next
week. Diurnal convection, along with the potential for mainly
mountain valley morning fog/low stratus, will return by the middle
of next week.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...WJM
NEAR TERM...HG/PM
SHORT TERM...WJM
LONG TERM...WJM
AVIATION...HG/PM
Area Forecast Discussion
National Weather Service Marquette MI
830 PM EDT Fri Jul 2 2021
.SHORT TERM...(This evening through Saturday)
Issued at 332 PM EDT FRI JUL 2 2021
Visible satellite shows just a small patch of cloud cover moving
into the north-central U.P. right now, this the dying remains of
some showers that dropped south out of Northern Ontario and across
Lake Superior. Earlier, had included isolated showers in the
forecast for the next couple of hours, but seeing how much they`ve
dried up, decided to knock that down to just "sprinkles" for the
next couple hours. Behind that, a more robust second batch of
showers and storms is diving south through Northern Ontario towards
Lake Superior. These showers are associated with a band of fgen and
theta-e advection on the leading edge of the warm air mass wrapping
around a strong ridge over the Northern Plains, and are being fed by
roughly 500 to perhaps 1000 J/kg of MUCAPE in the warm air behind
the front. GLM data shows the complex of storms has been maintaining
its intensity, so while most CAMs are pretty bearish, have included
slight chance to chance POPs/thunder for the east half this evening.
Given the current trajectory on satellite, it`s possible the POPs in
this forecast still aren`t quite far enough west.
Tonight, with the aforementioned ridge to the west and WAA from the
north, temps will not decrease much from where they are now already.
A developing WNW downslope wind into Marquette will likely keep them
in the 60s overnight. In other areas, even where there won`t be a
downslope contribution to the temps the wind will still remain up
through the night preventing effective mix out and radiational
cooling. A patch of wildfire smoke overhead right now has kept temps
this afternoon a couple degrees cooler than forecast, and the RAP
integrated smoke model shows a similarly high concentration of it
remaining overhead through about midnight which also will limit
temps from cooling off too much. That patch of showers or
thunderstorms that will be moving into the east this evening should
pull away by about 01-02z.
Tomorrow still looks hot, with that ridge over the Northern Plains
pushing eastward into the Upper Mississippi Valley and 850 mb temps
rising to around 21-22 C. The RAP shows most of the wildfire smoke
pushing off to the south before sunrise, so smoke should have less
of an impact on temps tomorrow. Mixing to around 850 mb will support
highs ranging from the mid 80s to the low 90s. A fairly stiff NW
wind should keep the Lake Superior lakebreeze offshore for Marquette
and points west, so I have downtown Marquette getting into the mid
80s for a high although the immediate lakeshore probably will be
cooler. East of Marquette, onshore flow will keep temps in the 70s.
Conditions will be dry and mostly sunny - great for parades,
barbecuing, fireworks, or however you`re celebrating this holiday
weekend (as long as you can tolerate the warmth).
.LONG TERM...(Saturday night through Friday)
Issued at 339 PM EDT FRI JUL 2 2021
Hot conditions Independence Day are expected to gradually cool
throughout the early week as a cold front slowly progs through the
area. Expect showers and thunderstorms with this cold front passage.
We may see a few strong thunderstorms late Sunday afternoon into
Sunday night, but the confidence is not great. Expect drier
conditions during the middle of next week as another high pressure
ridge builds above us. By the end of next week, another low pressure
is predicted to move over us, bringing us more showers and
thunderstorms.
Independence Day should be hot! As the ensemble 850mb temps approach
the 99th percentile Saturday night, expect for the slightly cooler
850mb temps to be made up by better mixing in the boundary layer on
Independence Day. This should mixing should give the atmosphere
abundant CAPE to work with should convection fire off before a cold
front arrives Sunday evening. However, given that there is going to
be a strong inversion in place before the arrival of the front, it
doesn`t appear likely that showers or thunderstorms will develop
before then. Therefore, expect mostly sunny to partly cloudy skies
Sunday. Low 90s are expected across the interior areas, although the
areas where lake-breezes set up could lower highs a bit (these lake-
breeze boundaries would also be the places where convection would
fire-up should it occur).
The cold front looks to begin getting into the far western U.P. late
Sunday afternoon/early Sunday evening. This front should bring in
some showers and thunderstorms that move across the area from west
to east Sunday night. While no severe weather is currently expected
at the moment, bulk shear and MUCAPE values near the frontal
boundary do approach 30 kts and 1000-2000 J/kg, respectively;
therefore, there may be a few strong thunderstorms (wouldn`t be
impossible to rule out a marginally severe thunderstorm either right
now). The severe weather threat should become clearer the closer we
get to independence day; right now, it seems marginal at best. These
showers and thunderstorms associated with the cold front may put a
damper on those hoping to see fireworks on the evening of the 4th in
western and central Upper Michigan.
Expect showers and thunderstorms to continue Sunday night into
Monday as the cold front slowly progresses through. Kept a chance of
thunder going through Sunday night into Monday as MUCAPE values do
see to be around 1000 J/kg throughout the night and the front
should, in my estimation, provide enough lift to overcome the
weakened inversion cap at the top of the boundary layer. Partly
cloudy skies throughout the day should provide enough diurnal
heating to ramp up more thunderstorms during the day Monday (even
though highs look to be a bit cooler than what is expected on
Independence Day). The front and precipitation associated with it
should end by Tuesday morning.
Expect much cooler conditions Tuesday and Wednesday of next week
behind the cold front. Highs should be in the 60s and 70s, whereas
lows during the nights could get to the 40s in the interior areas
(even the low 40s in the interior west). Given that a high pressure
ridge is predicted to be building over the area during this time, no
precipitation (and clearer skies) are expected. Temperatures should
gradually warm again throughout the late week next week ahead of
another low approaching Upper Michigan.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 830 PM EDT FRI JUL 2 2021
Exepct VFR conditions through the forecast period. A period of
marginal LLWS may develop at SAW with WSW sfc wind quickly veering
to NW in the lowest 1000 ft. Shear will diminish by early morning as
sfc wind veers around to NW as well.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 332 PM EDT FRI JUL 2 2021
Expect winds generally 15-20 kts or less across Lake Superior
through Monday. A cold front will pass through the area on Monday,
potentially accompanied by a few thunderstorms. Could see some gusts
to 20-25 kts in the wake of the front Monday night into Tuesday over
the east half of Lake Superior before winds relax to 15 kts or less
again on Wednesday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...RJC
LONG TERM...TAP
AVIATION...JLB
MARINE...RJC
Area Forecast Discussion
National Weather Service Pueblo CO
320 PM MDT Fri Jul 2 2021
.SHORT TERM...(This evening through Saturday)
Issued at 319 PM MDT Fri Jul 2 2021
Main Forecast Concerns/Challenges:
1) Isolated to scattered thunderstorms through mid evening across
the mountains, mountain valleys, and locations along and west of I-
25. Severe threat is low, though a stronger storm or two can`t be
ruled out. Isolated flash flooding threat, including the burn scars,
will continue as well.
2) Returning thunderstorm chances Saturday afternoon across southern
CO, with the potential for strong to severe storms over the plains
during the afternoon hours.
Isolated development of slow moving thunderstorms continues at this
time, mainly over the mountains and mountain valleys. Storms have
not been overly robust, but have been efficient rain producers. This
has supported a continued flash flooding threat this afternoon, and
expect this to continue through early to mid evening. Any location
that observes persistent thunderstorm development will have a flash
flood threat. This flash flood threat includes the burn scars, but
think the Junkins and Spring burn scars will have the highest
potential. While much of the development is still expected to be
west of I-25 over the mountains and mountain valleys, think there is
some potential for isolated development to approach the I-25
corridor before the storms end later this evening. Thermodynamic
profiles and weaker shear still don`t really support
robust/organized development into this evening. However, latest RAP
analysis is showing some weakening of the MLCIN across the southern
I-25 corridor along with some slight enhancement to the wind field.
So, think that if a stronger storm were to develop this evening
think it would have the highest potential to do so across the
southern I-25 corridor.
Well defined shortwave trough is forecast to dive southeast across
CO on Saturday, while lee surface trough deepens in the afternoon.
This focus and support along with returning instability and stronger
flow/bulk shear will support a threat of strong to severe storms
across the plains. Initial threat looks to be early to mid
afternoon along and just to the east of the I-25 corridor, with
development then expected to push east through the plains during the
afternoon hours.
.LONG TERM...(Saturday night through Friday)
Issued at 319 PM MDT Fri Jul 2 2021
Main Forecast Concerns/Challenges:
1) Burn scar monitoring needed Monday and Tuesday
2) The heat returns starting Thursday
Saturday night and Sunday...Convection is expected to start
dissipating from west to east between 9 PM and midnight, with partly
cloudy skies and mild conditions overnight. A weak cold front pushes
into eastern CO Sunday morning, which will help to spark showers and
storms along the eastern mts by midday. Models indicate that the
dryline will likely stay along and east of the CO/KS state line, but
that will have to be reassessed as Sunday nears since stronger
storms will be lurking. Overnight lows will cool into the upper 40s
to upper 50s for the high valleys, and 50s to around 60F for the
plains. On Sunday the aftn highs are forecast to be in the mid to
upper 80s for the high valleys, and mid 80s to mid 90s for the
plains.
Monday and Tuesday...The upper ridge will slide to the north and
northwest to begin the week, allowing an upper disturbance to cross
the northern Rockies on Monday. This upper level support, coupled
with available moisture and winds turning more easterly, will help
initiate more convection over the mts and adjacent plains Monday
aftn and eve. As this disturbance continue east-southeast overnight,
a cold front will push into eastern Colorado early Tuesday, setting
up for a slightly cooler day but with another enhanced round of
convection firing off of the higher terrain by midday. Area burn
scars will need to be monitored both days. As for temps, the high
valleys will warm into the 80s both days. Across the plains, expect
the mid 80s to mid 90s on Mon, then about 5 degrees cooler on Tue.
Wednesday through Friday...The upper high will be centered over the
Four Corners through the end of the work week, producing very hot
temperatures and just isolated convection chances, mainly tied to
the mts. Plan on highs each day in the 80s for the high valleys, and
90s to near 100F for the plains. Moore
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 319 PM MDT Fri Jul 2 2021
Any lingering MVFR ceilings across the TAF sites, particularly COS,
will continue to diminish in the near term. VFR conditions then
expected for the remainder of the TAF period, though some potential
for patchy fog across COS early Saturday morning. Still expect some
potential for isolated showers or storms to move around the ALS area
this evening, with some potential for isolated development to move
near COS and PUB. If this were to occur, expect any showers or
storms to be brief with dry conditions then expected later this
evening and overnight. Thunderstorm development expected once again
on Saturday, with COS and PUB having the highest chances to observe
this development during the afternoon hours.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RODRIGUEZ
LONG TERM...MOORE
AVIATION...RODRIGUEZ