Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/28/22
Area Forecast Discussion
National Weather Service Cleveland OH
916 PM EDT Wed Jul 27 2022
.SYNOPSIS...
Weak low pressure moves across northeast Ohio into western New
York through the evening pulling a cold front eastward with it.
Another cold front is expected to cross the region Thursday
night into Friday morning. High pressure returns Friday, then
persist into the weekend.
&&
.NEAR TERM /THROUGH THURSDAY/...
915 pm update
No impactful forecast changes were needed at this time.
700 pm update...
We have toned down the previous forecast with the hourly POPs to
isolated and widely scattered. The inherited forecast was a bit
too high on the POPs this evening. We have adjusted the POPs
this evening and overnight to better reflect the latest HRRR
model run and coverage. The rest of the forecast looks fine at
this time.
Previous discussion...
Weak low pressure moves across northeast Ohio into western New
York through the evening pulling a cold front eastward with it.
There is a 7H jet of around 40 knots but its influence looks to
be mainly the central and southern portion of the state. Also
there is a lack of low level instability across northern OH into
NW PA so really no threat for severe weather. So for now have
increased the rain chances across the entire region. Thunderstorms
look to be scattered at best.
Highs this afternoon limited by the showers and cloud cover
with 70`s to maybe lower 80`s. Lows tonight should be warmer
with the increased low level moisture. So expect to see lows in
the 60`s to lower 70`s.
Showers should end from west to east through Thursday morning
with most areas dry during the afternoon. There should be a decent
amount of sunshine so it will be warmer. Highs in the 80`s.
Stronger cold front moves into the area Thursday night with an
increase of showers and thunderstorms along and ahead of it.
Current thinking is that moisture levels will be slightly
decreased with only scattered coverage to the convection. Lows
Thursday night should range from the upper 50`s to mid 60`s.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
The cold front
will be slow to push south of the region Friday morning as it
hangs up over central Ohio in response to another mid/upper
shortwave dropping through the central Great Lakes as it rounds
the base of a closed mid/upper low traversing eastern Ontario
and Quebec. The front remaining over central Ohio through mid
day and increasing upper level forcing as a 100-105 knot H3 jet
sinks into the lower Great Lakes will lead to continued isolated
to scattered showers and thunderstorms over the far SE counties
in the morning and early afternoon before the boundary finally
pushes south, allowing drier air to begin to build in. Highs
Friday will be in the upper 70s/low 80s with decreasing
humidity. The aforementioned shortwave will push through the
eastern Great Lakes and NE CONUS Friday evening and Friday night
followed by a strong 1022-1024 mb Canadian surface high
shifting over the Ohio Valley Saturday and Saturday night. This
high along with a broad mid/upper trough over the Great Lakes
and NE through the weekend will bring mostly sunny skies and
continued comfortable temperatures and humidity. Highs Saturday
will remain in the upper 70s/low 80s with dew points only in the
50s. A great day to give the AC a break before the heat comes
back in a big way later next week. More on that below.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The surface high will remain over the Ohio Valley early Sunday
before shifting into the NE CONUS and Mid-Atlantic late Sunday and
Sunday night. The return southerly flow on the backside of the high
will start to advect warmer, more humid conditions into the region
Sunday night with the old frontal boundary lifting northward as a
warm front. Guidance continues to differ on how quickly the warm
front will lift north, and suspect it will be a bit slower given the
strong surface high in place ahead of it. For this reason, delayed
the onset of slight chance PoPs for showers and thunderstorms until
late Sunday night, with better chances arriving Monday as a well-
defined northern stream mid/upper shortwave approaching from the
Upper Midwest pulls the front directly over or just north of our
region, along with some better upper jet support. Forcing and shear
parameters look weak overall, so expect the thunderstorms to mostly
be garden variety, although cannot rule out localized downbursts
given the likelihood of at least moderate instability if sufficient
heating can take place. The aforementioned shortwave will dive
through the lower Great Lakes and Ohio Valley Monday night pulling a
cold front through the region, so kept high chance PoPs for showers
and thunderstorms through the night (broad brushed over the entire
area) until we can get a better feel on the exact timing of the
front. Highs Sunday will warm into the mid 80s with comfortable dew
points continuing before highs in the mid/upper 80s and dew points
in the upper 60s to near 70 return Monday.
For the Tuesday and Wednesday time period, deterministic and
ensemble guidance is in fairly strong agreement that an unusually
potent 594-598 DM H5 ridge that has been baking the Rockies and High
Plains will progress east into the central Plains and Mississippi
Valley as the mid/upper trough axis shifts into the far eastern
Great Lakes and New England. This will advect a bubble of anomalous
heat and humidity (highs possibly around 100 F) into the Plains,
cornbelt, and western Great Lakes by Wednesday, with the axis of
extreme heat sitting just west of our area. This will lead to NW
flow aloft across the Great Lakes and Ohio Valley with the cold
frontal boundary from Monday night slowly lifting NE as a warm front
Tuesday into Wednesday. This pattern could bring MCS activity, or at
least MCS remnants, across our area for the midweek period as a
strong instability/theta e gradient will bisect the region. For this
reason, added chance to slight chance PoPs Tuesday through Wednesday
since I cannot guarantee a dry forecast in this pattern. Highs
Tuesday will continue in the mid/upper 80s before warming to near 90
Wednesday.
Looking farther ahead to next Thursday through the following
weekend, there is remarkable model consensus that the anomalous H5
ridge will continue to slide east through the Ohio Valley and into
the East Coast. This could bring a few days of high heat and
humidity, possibly the warmest temps of the summer, if current
trends hold. The Climate Prediction Center has a high risk for
excessive heat in the August 4-6 time period across all of northern
Ohio and NW PA for this potential heat wave, so those with outdoor
plans should start to plan accordingly.
&&
.AVIATION /00Z Thursday THROUGH Monday/...
Mainly VFR conditions are expected but there may be times MVFR
ceilings could sneak in this evening. MFD, CAK, CLE, YNG, and
ERI may see some MVFR ceilings between 10z and 13z late tonight
into early Thursday morning. There also could be a touch of
light fog/mist at MFD down to 5sm late tonight. Otherwise, any
lower morning ceilings will rise back to VFR later in the
morning through the afternoon. There could be a few widely
scattered showers this evening but have left those out of any
TAF forecast at this time. The probability of any shower
impacting a site is too uncertain to mention in the TAF. Winds
will be southwesterly to west-southwesterly 5 to 10 knots
through the period.
Outlook...Non-VFR possible in showers and thunderstorms
Thursday night.
&&
.MARINE...
A cold front will cross Lake Erie tonight with W winds of 10-15
knots behind it and waves building to 2 to 3 feet. W to SW winds
increase to 15-20 knots Thursday afternoon with 2 to 4 foot waves.
This will bring a moderate risk of rip currents for the central and
eastern basins. At this time, feel that we will stay just under
Small Craft criteria, but it will be close in the eastern basin
given the longer fetch. A secondary cold front will cross the lake
Thursday night with winds shifting to NW and decreasing to 5-10
knots. Quiet conditions are then anticipated Friday through Saturday
night with light W to NW winds of 5-10 knots as high pressure
settles overhead before winds turn more southerly Sunday. SW winds
are then expected with a warm front lifting onto the lake Sunday
night into Monday with speeds increasing a bit to 10-15 knots at
times.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...MM
NEAR TERM...Griffin/MM
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...Griffin
MARINE...Garuckas
Area Forecast Discussion
National Weather Service Cheyenne WY
745 PM MDT Wed Jul 27 2022
.UPDATE...
Issued at 734 PM MDT Wed Jul 27 2022
Severe Thunderstorm Watch issued for the southern Panhandle this
evening. HRRR mesoscale guidance showing a few storms developing
in the next couple hours and continuing through 06Z. May end up
capping off as suggested by other mesoscale guidance. Will stay on
the safe side though with the watch after what happened here in
Laramie County.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 200 PM MDT Wed Jul 27 2022
The risk for showers and thunderstorms remains in place over far
southeast Wyoming and western Nebraska this evening. Thick morning
stratus cloud cover has somewhat delayed the onset time for
convective initiation, as evidenced by notable capping on SPC RAP
mesoanalysis and a relative lack of robust cumulus anywhere east
of I-25. CAM guidance has trended later with onset times, most
notably the HRRR which now shows no real robust convection any
earlier than the 23z-0z timeframe. The most likely outcome for
this evening appears to be typical orographic convection off the
Laramie Range. If capping can be overcome to the east of I-25, any
thunderstorms that can sustain themselves off the higher terrain
will have robust surface moisture (Tds in the mid to upper 50s)
and decent speed shear (45kts+ per latest RAP). One or two
dominant supercells may emerge, with a large hail and outflow wind
gust threat. While the current SPC outlook does mention a very low
tornado threat, this may be ultimately be tied only to areas in
western Nebraska, closer to where a lingering outflow boundary
from morning convection resides. Showers and thunderstorm activity
should generally wind down after around 9pm and translate south
and eastward into Colorado. Lingering moist upslope flow in the
wake of this activity may result in another round of overnight fog
and stratus. Have added low-end probabilities of surface fog in
this forecast package from midnight through sunrise Thursday
morning.
The Thursday forecast, which once looked quite wet on
deterministic and ensemble guidance a few days ago, has continued
to trend drier. PWAT normalized anomalies from latest global
models are only running around 1-2 sigma in the band of moisture
set to arrive from the northwest. Still, a subtle shortwave
passing through in west-northwest flow will assist with lift
during the afternoon. Showers and thunderstorms should remain
confined to the higher terrain in southern Wyoming. Will have to
watch the potential for heavy rain and isolated instances of flash
flooding in higher terrain and in any burn scar areas. High
temperatures will be notably cooler on Thursday, running around 10
degrees below average with cloud cover and rain assisting in the
temporary below-average trend.
.LONG TERM...(Thursday night through Wednesday)
Issued at 200 PM MDT Wed Jul 27 2022
Little to no changes to the long term from the previous forecast.
The long term forecast period remains relatively inactive, with the
exceptions of the first and last days: Friday and Tuesday. Friday,
as a trough to the northeast pushes off, we get the last bit of a
moisture surge before a ridge cuts us off from the moisture source.
Friday we will likely see scattered showers and thunderstorms across
southeast Wyoming and the Nebraska panhandle, especially on the
southern and western fringes of the CWA where the better moisture is
set up.
Conditions dry out and warm up Saturday through Monday with high
temperature creeping back into the upper 80s to 90s. There`s a
chance for the higher terrain to see a thunderstorm or two over the
weekend, but the chances remain low and will be highly dependent on
how much moisture remains in the area.
Tuesday looks to be the next active day after Friday as we get once
again, another monsoonal surge into the western portions of our CWA.
The ECMWF, GFS, and Canadian are all showing similar patterns and
timing, giving us higher confidence in this occurring. However, as
this is still 7 days out, there is plenty of time for conditions to
evolve and change.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1104 AM MDT Wed Jul 27 2022
Low clouds will continue to dissipate late this morning. SNY is
expected to scatter out early this afternoon as mixing erodes the
low stratus layer. After 21z, showers and thunderstorms are likely
for CYS, SNY, BFF and AIA. Thunderstorms will likely bring CIG and
VIS into the MVFR and perhaps IFR ranges, especially farther east
at SNY. Gusty outflow winds from the west northwest are possible,
however general wind flow outside of storms will remain mostly
light easterly. Overnight, low stratus and fog is indicated by
several ensemble model members, and will likely bring ceiling
heights into the MVFR and possibly IFR range at SNY and CYS.
&&
.FIRE WEATHER...
Issued at 142 PM MDT Wed Jul 27 2022
Increased surface moisture as well as showers and thunderstorms
will keep fire weather concerns relatively low over the next few
days. Showers and thunderstorms are likely today, with wetting rains
possible once again on Thursday. A drying trend will move in for the
weekend however isolated showers and storms remain possible in the
higher terrain. Overall, winds will remain below 20 knots outside any
thunderstorm outflow with RH values remaining above 20% through the
period.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
UPDATE...GCC
SHORT TERM...MAC
LONG TERM...LK
AVIATION...MAC
FIRE WEATHER...MAC
Area Forecast Discussion
National Weather Service Dodge City KS
1102 PM CDT Wed Jul 27 2022
...UPDATE TO SYNOPSIS AND AVIATION...
.SYNOPSIS...
Issued at 1100 PM CDT Wed Jul 27 2022
WV imagery indicates a westerly flow aloft prevailing across the
Western High Plains. Near the surface, a near stationary frontal
boundary extends off of an attendant low in the Texas Panhandle east-
northeast into Northern Oklahoma.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 1226 PM CDT Wed Jul 27 2022
17Z obs are showing a mixture of clouds and sun with a stalled
frontal boundary from northern Oklahoma to southeast Colorado.
There is also a dying MCS in south central Nebraska which is
pushing an outflow boundary from northeast Colorado to northwest
Kansas. Robust moisture is all across the region with dewpoints in
the mid to upper 60s and PW values in the 1.5 inch range. In the
upper levels the winds have turned to the northwest as a low
centered over central Canada has pushed the polar front far
enough south to have the northwest flow in the region. In the mid
levels an upper level high in the southern plains is leading to
mainly westerly winds and this will bring in periodic shortwaves
which will lead to our rain events coming up from tonight through
Saturday.
For tonight models are forecasting two areas of storms to develop.
The first is in southeast Colorado this afternoon in the vicinity
of the stationary front with an upper level shortwave moving off
the Rockies. These storms should move into southwest Kansas and
the Oklahoma panhandle through the evening and continue through
the Red Hills by midnight as the mid level lift with the wave is
showing to remain in the ARW/HRRR/RAP models. Another MCS is
forecast to develop with a shortwave in the Nebraska panhandle and
dive southeast through the evening into northwest Kansas. The
momentum and propagation of the storms should take it into our
northwest zones before midnight and could affect areas around Hays
with some brief gusty winds. The latest trends have been showing a
more western propagation of the MCS. Given the moisture fields
and CAPE forecasts are showing higher amounts from Dodge to
Syracuse combining with the residual outflow from the earlier MCS,
I like this idea and increased POPs with the overnight MCS. Most
of the models are suggesting the CAPE will diminish quickly after
midnight so we should expect storms to quickly subside towards
sunrise...however expect residual clouds for much of the overnight
and lows will be in the upper 60s.
Thursday we will probably start the day with a break in the rain
in the morning and then by afternoon the rain and storms will
start to ramp up again. A large mid level wave ejects out of
Colorado in the afternoon and combining the present moisture along
with the monsoonal flow we should have a large area of rain and
storms breaking out in southeast Colorado and far western Kansas.
With upslope winds all day and more clouds than sun models are
keeping us in the 80s for highs. Overall QPF amount potential for
tonight through Thursday has a good swath of around 1 inch of rain
with our better chances and higher amounts coming Thursday night
into Friday.
.LONG TERM...(Thursday night through Wednesday)
Issued at 205 PM CDT Wed Jul 27 2022
Heavy rain and flash flooding risk is still on track for Friday.
WPC has a moderate risk of excessive rain from Dodge City to
southeast Colorado during the day and a slight risk for the rest
of southwest Kansas. Updated models are varying a bit on location
of the heaviest rain with the NAM being along the Oklahoma border,
the GFS in the central portions of the CWA and the Euro staying
consistent for area along and north of highway 50. The latest Euro
QPF forecast is painting a swath of 4-6 inches of rain from Scott
City to Pratt. It does look like we should have a good area of
700mb convergence across southwest Kansas and loads of lower and
mid level moisture during the day. The other factor that bears
watching is where the surface and 850 mb high set up as this will
determine where the heaviest rain forms as well as where the
moisture will be scoured out. At this point the high is centered
in eastern Nebraska and Kansas which would keep much of our area
in the best rain making zones. Temperatures on Friday should also
stay pretty cool for this time of the year as clouds, rain, east
winds, and 850 mb temps being brought in by the cooler high will
be around 15(C) that it could be struggle to get into the low 70s
in the afternoon.
Saturday should be another decent chance of rain mostly in the
morning and early afternoon as the 500-700 mb convergence zone
slowly shifts to the east with the stationary frontal boundary
starting to lift to the north as a warm front in the afternoon.
The last bit of rain should rap up by Saturday evening with the
last shortwave moving from Colorado into south central Kansas.
Overall it looks like a decent chance of the entire CWA seeing at
least 1 inch of rain with the potential of somebody getting 6
inches or more. Given the great lack of soil moisture and how a
lot of the soil can absorb some water...aerial flooding impacts
will be minimal outside of smaller creeks and ditches. However
areas prone to flash flooding will need to be monitored. It will
be a good event to help fill up some of the lakes and rivers.
Sunday we see the ridge in the Rockies start to build back in and
the temperatures will start to heat up. We should see highs back
to around 90 degrees.
Next week the ridge comes back into the central plains and we will
go back to summer time with temperatures approaching 100.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1100 PM CDT Wed Jul 27 2022
An area of thunderstorms will continue to track eastward along the
Oklahoma border in southwest Kansas overnight affecting the vicinity
of KLBL generally after 05Z. Another round of thunderstorms will be
possible during the day Thursday, potentially a little more widespread.
Otherwise, mainly VFR conditions are expected to continue through much
of the period. Light east-southeast winds are expected to persist
through late Thursday as a near stationary frontal boundary remains
situated generally along and south of the Oklahoma border.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 84 64 73 / 40 40 80 70
GCK 66 81 62 70 / 40 50 80 70
EHA 66 81 62 73 / 50 70 90 80
LBL 67 84 63 74 / 40 60 80 80
HYS 66 81 62 75 / 60 40 40 40
P28 73 88 66 76 / 50 40 80 70
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Grand Rapids MI
956 PM EDT Wed Jul 27 2022
LATEST UPDATE...
Update
.UPDATE...
Issued at 956 PM EDT Wed Jul 27 2022
It`s been fairly quiet so far this evening, but chance of showers
should ramp up just a bit late tonight as the sfc cold front and
mid level shortwave approach. Pops still only 20-40 pct though as
coverage expected to be widely scattered at best.
Low level convergence progs favors the MKG to RQB area for
showers initially in the 09Z to 12Z timeframe, shifting southeast
with time then favoring areas from GRR to the south and east 12Z-
15Z. Drying out after 15Z Thursday from the west, with dry/breezy
weather prevailing in the afternoon.
Bad time of day for fropa to produce much of a thunder threat,
but can`t rule an isolated tstm with MUCapes of 400-800 J/KG, a
low level jet of around 30-35 kts, and nearly 50 kts of deep
layer shear (per RAP guidance).
The Beach Hazard Statement and Small Craft Advisory still looks
good on Thursday. Latest RAP guidance has 20-25 kts sustained
low level westerly flow coming in behind the front, and the cold
advection atop warm water temps of 70-75 degrees will definitely
kick up the waves/currents at west Michigan beaches.
&&
.DISCUSSION...(This evening through next Wednesday)
Issued at 245 PM EDT Wed Jul 27 2022
- Scattered showers into Thursday
Convection will be limited late this afternoon and evening. That
is due to the dry air at mid to high levels, allowing the updrafts
to ingest too much dry air, once they get above 20000 ft. We do
have over 1000 j/kg of surface based cape our Southwest Michigan
and with the cold front moving across the area with evening we
will have surface convergence. However all that dry air above 700
mb will kill the updrafts once the get above 700 mb. The evening
showers (what few there are) are due to a cold front pushing
through the area.
Thursday morning, the upper trough comes through and that will
result in a few scattered showers. Like today though, the dry air
above 700 mb will limit the activity. Still some showers will be
around mostly mid morning into early afternoon.
- Dry but cooler Friday and Saturday
Another in a long series of cold core upper lows moves through the
Great Lakes during this time. This system has a weak shortwave
that rotates through the area Friday night. That shortwave tries
to create it`s own upper low. It may have some sprinkles with it
as it comes through.
More than anything else this will bring our area below normal
temperatures through Saturday.
- Warming early next week with convection Monday into Tuesday
Once that system gets east of here we get a warm up. That does
not last all that long since there is yet another upper low
dropping south from northern Canada. This will bring the risk of
showers and thunderstorms Monday into Tuesday. Currently, Monday
looks like the warmest day.
- Then the heat returns
Finally by the middle of next week, the upper high that has been
parked over the western CONUS for quite some time, redevelops
over the eastern CONUS by the middle of next week. With the
center of the upper high over the Ohio, that puts Southwest
Michigan in an ideal area for hot weather. The question that we
have to answer is will yet another closed upper low come in and
end the heatwave before it is a chance.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 758 PM EDT Wed Jul 27 2022
VFR weather is expected to prevail tonight and Thursday, however
scattered showers early Thursday could bring brief MVFR or lower
conditons if any of the heavier rain showers impact the terminals.
West winds behind the cold front on Thursday will increase and
become gusty by afternoon: 12-15 kts sustained, with gusts to 25
kts.
&&
.MARINE...
Issued at 203 PM EDT Wed Jul 27 2022
We have issued a Small Craft Advisory and Beach Hazard for
Thursday. This event is another one of those northwest flow, cold
advection events the models tend to underplay. We are thinking 3
to 5 foot waves are likely Thursday. There will be two periods
higher winds and waves. The first is the morning behind the first
cold front, then toward evening a second push of cold air, where
the winds will turn more to the north northwest, will be the
second peak. That is why we have the headlines going into the
evening. Beyond that I do not see marine headlines until early
next week.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 5 AM EDT Thursday through late
Thursday night for MIZ037-043-050-056-064-071.
LM...Small Craft Advisory from 5 AM Thursday to 2 AM EDT Friday for
LMZ844>849.
&&
$$
UPDATE...Meade
DISCUSSION...WDM
AVIATION...Meade
MARINE...WDM
Area Forecast Discussion
National Weather Service Northern Indiana
739 PM EDT Wed Jul 27 2022
.SYNOPSIS...
Issued at 734 PM EDT Wed Jul 27 2022
A front will drop southeast through the region and bring a chance
of showers and perhaps a thunderstorm this evening. Lows tonight
will be in the lower to middle 60s. A low chance for showers
lingers into Thursday morning. Thursday afternoon highs reach the
upper 70s and lower 08s. High pressure then brings dry weather
with seasonable temperatures this weekend.
&&
.SHORT TERM...(This Evening through Thursday)
Issued at 236 PM EDT Wed Jul 27 2022
Extruded monsoonal moisture remains steadfast Central Plains into
Indiana/Ohio providing multilayer mid/high clouds stream.
Beneath. morning stratus developed across much of CWA as 925 mb
flow ramped/backed southwesterly over southern Illinois/Indiana
overnight. This allowed for tap of rich, 14.5-16 g/kg, moisture to
advect northward into CWA. Within northern stream, cyclone dips
through Ontario through Thursday sharpening longwave trough while
a series of embedded shortwaves swing through faster Upper Great
Lakes mid level flow. First shortwave and attendant frontal band
from Lake Superior to Quad Cities early this afternoon will track
eastward through CWA this evening and provide impetus for a chance
of showers/slight chance thunderstorm. Question will be how much
destabilization will be realized over northern Indiana. Only
modest upstream instability, up to 1000 J/kg MLCAPE by 21 UTC per
RAP mesoanalysis over southwest Lake Michigan to west central
Illinois. Less favorable downstream conditions with thick/layered
cloud cover limiting afternoon insolation with slow MLCIN erosion
noted through midday over CWA. Given paltry mid level lapse rates,
followed by start of nocturnal cooling, any convection to remain
relatively shallow and decay as it tracks east-southeast in
advance of front through the evening hours, despite 30-35 knots
effective layer shear present.
Secondary trough rotates through early Thursday, sufficient for
low chance PoPs, primarily midday/afternoon. With mid level cold
pool/5H height falls remaining north and lifting into southeast
Canada through the day and disfavorable timing, not sufficiently
impressed for thunderstorm chance mention at this time.
&&
.LONG TERM...(Thursday Night through Wednesday)
Issued at 236 PM EDT Wed Jul 27 2022
Mid level trough progressively lifts out eastern Canada
Friday/Saturday, followed by a more zonal pattern. Meanwhile
strong/subsident anticyclone dives southeast from the Dakotas and
envelopes southern Great Lakes/Ohio Valley this weekend. Dry with
gradual thermal moderation to near normal by Sunday. North Pacific
shortwave brings next front with relatively low chance PoPs
Monday/Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 734 PM EDT Wed Jul 27 2022
Predominantly VFR conditions are expected at the TAF sites, with
brief periods of MVFR possible at KFWA. A cold front will pass
through the area, bringing chances for showers and thunderstorms
and a wind shift to the west-northwest. A line of the heavier showers
and thunderstorms (greater likelihood of MVFR conditions) has
drifted east of KSBN, so left VCSH in for the next hour or so and
then continue with dry conditions overnight. The line should
impact KFWA anytime between 03z-7z (if it survives), with the
potential for thunderstorms waning as it moves eastward. It`s
possible the line completely falls apart before reaching KFWA, but
felt confident enough to at least include chances for showers.
Left out thunder for now. Otherwise, behind the line we`ll see
clearing skies for a brief period which could lead to some BR
development or lower ceilings) between 9-12z at KFWA, so have
included this in the TAF for now.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Murphy
SHORT TERM...Murphy
LONG TERM...Murphy
AVIATION...MCD
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Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1021 PM CDT Wed Jul 27 2022
.UPDATE...
Issued at 1017 PM CDT Wed Jul 27 2022
Updated for 06z aviation discussion.
&&
.DISCUSSION...(This evening through Wednesday)
Issued at 240 PM CDT Wed Jul 27 2022
KEY MESSAGES:
- Generally dry conditions with increasing temperatures this weekend
into next week.
- The highest chance for rain is late Sunday into Sunday night.
Thunderstorms are possible but the threat for severe weather is
low.
Today through Friday...Early afternoon satellite imagery together
with radar and RAP13 surface analysis showed clouds scattered across
the Upper Midwest. A few of the deeper areas of convection were
managing to produce some showers across northern Minnesota and
northern Wisconsin, with another area across the south near I-90.
This will continue to be the trend the rest of the afternoon, with
decreasing coverage toward the evening.
Severe weather is not expected, but forecast soundings show an
inverted V-signature which means that gusty winds are possible under
any showers as the rain-cooled air falls to the surface. RAP
soundings also show a few hundred J/kg of MUCAPE across southern
Minnesota, so some lighting also can`t be ruled out.
Overnight skies will clear and winds will decrease. On Thursday
another area of showers will be possible, mainly north of I-94, but
the coverage should be less than today. Highs on Thursday will be a
bit cooler, only in the mid 70s.
Saturday through Wednesday...A low amplitude shortwave will approach
from the west, with warm air advection beneath it as the surface high
pressure retreats southeast toward the Ohio River Valley. Forecast
guidance indicates a few showers and thunderstorms across western
Minnesota Saturday night, followed by a break Sunday morning, and
a chance for redevelopment Sunday evening and overnight. The winds
throughout the column are fairly light, and surface dewpoints are
only in the 60s, meaning only marginal shear and instability for
thunderstorms. Forecast guidance does suggest convection develop
later on Sunday, but neither severe weather, nor widespread rainfall
is expected. Looking ahead, southerly flow will return on Tuesday,
which will bring warmer air across the region mid-week. Highs on
Wednesday are in the 90s, but the GEFS ensemble has some extreme
values in there, which seem to be overdone. So at this point, it
looks like another solid stretch of warm summer weather, with only a
small chance for dangerous heat.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1017 PM CDT Wed Jul 27 2022
VFR conditions and west-northwesterly winds expected the entire
period. Winds will increase to 10 to 15 knots Thursday afternoon with
gusts to near 20 knots before slowing again Thursday evening. A fair
weather cumulus field should develop around 5000 feet late Thursday
morning and last through Thursday afternoon.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
Fri...VFR. Wind NW 5-10 kts.
Sat...VFR. Wind S 10 kts.
Sun...VFR. Chc MVFR/TSRA late toward 00Z Monday. Wind SSW 10-15 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
UPDATE...CTG
DISCUSSION...JRB
AVIATION...CTG
Area Forecast Discussion
National Weather Service San Francisco Bay Area
443 PM PDT Wed Jul 27 2022
.SYNOPSIS...Seasonable conditions prevail through the week with a
slight warming trend across the interior. Otherwise, look for
periods of night and morning clouds near the coast and adjacent
valleys giving way to mostly sunny conditions each afternoon.
Monsoonal moisture arrives late week into the weekend.
&&
.DISCUSSION...as of 01:15 PM PDT Wednesday... A 2000 foot marine
layer moved ashore overnight and resulted in pockets of moderate
to heavy drizzle along the coast and for some coastal facing
slopes this morning. Several sites reported at least a hundredth
of an inch of accumulated drizzle while a handful reported a few
to several hundredths in the upslope portions of the SF Peninsula
and East Bay hills. As of early this afternoon, satellite imagery
depicts mostly clear skies across the majority of the region with
some lingering coastal stratus across the immediate coast. Very
little day over day change as of noon, with only 1 to 2 degrees
difference in temperature. Biggest change as of noon would be
breezy onshore winds near KSFO versus light offshore experienced
yesterday. Latest HRRR data indicates a thin veil of higher level
wildfire smoke from the Oak Fire moving westward towards the area
by this evening, through tonight, and into Thursday. Like the
initial arrival of this smoke into the region earlier this week,
it is expected to remain generally above surface level with no
significant impact to air quality per the HRRR near-surface smoke
prog.
A potent 596dm 500mb high pressure ridge will develop over the
Redding-Lassen-Tahoe portion of Northern/Northeastern California
through the remainder of the week. The PacNW and portions of N/NE
California will experience record high temperatures from this heat
dome while only the interior reaches of the Bay Area will respond
to this system. Expect a gradual warming of 3 to 6 degrees by
Friday across the interior, pushing those areas to the upper 90s
to low 100s, while nearshore and bayshores areas will remain
moderated by the marine air mass and remain similar to today, or
in the upper 60s to low 80s depending on distance to the nearest
shoreline. In addition, the high pressure system over the area
will gradually compress the marine layer through the coming days
meaning increased likelihood of fog and localized drizzle along
the coast and coastal slopes. The high pressure heat dome drifts
towards the ENE from Saturday PM and onward which will result in
gradual cooling across the interior and a deepening of the marine
layer nearshore.
Finally, monsoonal moisture will rotate clockwise around the high
pressure ridge through the next several days. Given the placement
of the ridge to the northeast, the flow around the ridge is more
conducive for advecting monsoonal moisture towards the Bay Area
and Central Coast. As such, expecting to see a surge of this
monsoonal moisture from the Desert Southwest through the late
week. PWATs in excess of 1.00" arrive regionwide tomorrow with
pockets of up to 1.25" possible by Friday morning. For now, models
are struggling to capture define the risk of elevated convection
from this moisture surge with generally sub 30 modified total
totals with intermittent values 32-34 in the deeper moisture
pockets. It is within these localized maxima that MUCAPE values
also are pushing 50-200 J/Kg very briefly, though, it looks much
less organized and concerning as the most recent event that
occurred early Tuesday morning along the eastern periphery of the
Bay Area. For now, best chance to see more than just general mid
level accus clouds would be early Saturday morning as PWATs
attempt to push to 1.3-1.4 with monsoonal surge from the SE
alongside a potential kicker of a trough positioned to the NW.
Confidence remains low but for now to seeing enough to warrant a
mention of thunderstorms in the immediate near term, however, the
time to watch will be the Saturday morning timeframe. Often times
do not see enough model/ensemble confidence with these events
until within roughly 24-48 hours, so will continue to monitor and
update as confidence increases.
&&
.AVIATION... As of 04:40 PM Wednesday... For the 0Z TAFs. VFR
throughout the region, except in patches of the immediate coast
where the marine layer stratus persists. Winds have peaked higher
than forecast with gusts to 26 knots at SFO and approaching 20 knots
at the Monterey Bay terminals, but are expected not to increase much
farther than that. Stratus returns this evening near 03-06z as the
marine layer expands again. Opted for persistence forecast. Skies
should clear around 16-18z with winds generally from the west at
around 10-12 knots.
Vicinity of KSFO... VFR throughout the day with west winds gusting
as high as 26 knots. Winds die down overnight as stratus pushes in
through the Golden Gate. Expect MVFR-IFR ceilings to develop rather
late (around 09z) as the bulk of the stratus aims for KOAK and the
East Bay Hills. Clearing around 17z, with west winds gusting to
around 20 knots Thursday afternoon.
KSFO Bridge Approach... Stratus might start filling in earlier than
observed at SFO. Otherwise similar to SFO.
Monterey Bay... VFR at KMRY and KSNS for the rest of the day with
winds from the northwest with gusts approaching 20 knots. Stratus
returns around 03z bringing IFR conditions, with high confidence for
LIFR ceilings at KMRY, and medium confidence for the same at KSNS.
Stratus clears around 17z with winds breezy from the west.
&&
.MARINE...as of 04:43 PM PDT Wednesday...Expect northwest winds to
increase into the weekend through the waters. Locally gusty winds
will also develop in the afternoons and evenings through the
Golden Gate to the Delta as well as along the coastal jets. Long
period south swell decreasing to moderate period later tonight.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...SF Bay
&&
$$
PUBLIC FORECAST: DRP
AVIATION: Dial
MARINE: Murdock
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Area Forecast Discussion
National Weather Service Reno NV
231 PM PDT Wed Jul 27 2022
.Synopsis...
High pressure aloft will yield hot and mainly dry conditions
through Saturday, with near record high temperatures likely coupled
with unusually warm overnight lows. High pressure breaks down Sunday
into Monday allowing for increased thunderstorm development. More
seasonal temperatures, and typical dry afternoon winds are projected
for next week.
&&
.Short Term (through Friday morning)...
* Main story the next few days is heat, with near record
temperatures lasting through Saturday. Skies will be mostly sunny
with lighter than average winds, making it feel even hotter to
those outdoors for extended periods of time. Coupled with this,
overnight lows will be unusually warm. This leads to high risk for
heat health impacts even among the general population and
especially those without access to air conditioning.
* Airmass through Thursday will be relatively stable, limiting t-
storm development for most areas. Latest satellite trends do show
some building Cu over Mono-Mineral Counties where NBM does have a
10-20% chance of storms. Similar pattern expected for tomorrow.
With temperatures around 100 you can`t entirely rule out something
bubbling up over the Sierra as far north as Tahoe and along the
Pine Nuts - where NBM shows a 7-10% chance of a storm each day.
* Smoke concerns look fairly minimal here on the east side of the
Sierra, based on current Oak Fire activity and latest HRRR Smoke
models showing limited transport flow over the Sierra. In fact
most transport flow on this side of the Sierra is northerly. Safe
to say we`ll at least have a light haze in the region, and the
model shows that, but not seeing indications of denser smoke
through Thursday.
-Chris
.LONG TERM...
Extended period of near record temperatures continues Friday and
Saturday when daytime high temperatures in desert valleys will
reach 100-105 degrees each afternoon with unusually warm overnight
temperatures increasing the heat health risk. High pressure
begins to break down over the weekend with high temperatures
dropping closer to 90 in the lower elevations by midweek.
Increasing thunderstorm coverage is possible on Sunday, and
potentially Monday as a trough of low pressure moves through the
Pacific Northwest increasing instability over the Sierra and
western Nevada. However, PWATs increase to near or above 1" Sunday
and Monday which has a history of creating widespread cloud cover
and limited thunderstorm activity, so thunderstorm coverage
remains lower on the predictability scale.
There will also be increasing chances for a day or two with
stronger winds as the trough brings cooling temperatures and
increasing surface gradients to the region, especially in
northwest Nevada. Breaking down of the high pressure ridge with
increasing thunderstorm coverage followed by gusty winds is a
classic fire weather pattern for the region, so we`ll have to keep
an eye on early next week for increased fire weather concerns.
-Zach
&&
.AVIATION...
Hot temperatures (100-105) in the valleys the next few days could
bring some density altitude issues with temperatures forecast to
cool off next week. Winds remain below average the next few days
as high pressure builds over the region.
A few thunderstorms remain possible the next few days, mainly in
Mono and Mineral counties. Storm coverage may spread throughout
the region on Sunday and Monday as a trough passing by the north
increases instability. Areas of haze with slantwise visibility
reductions will remain possible with ongoing fires in California,
but upper level flow is currently keeping thicker haze and smoke
on the west side of the Sierra. -Zach
&&
.REV Watches/Warnings/Advisories...
NV...Heat Advisory from 11 AM Thursday to 10 PM PDT Saturday
NVZ001-003>005.
CA...Heat Advisory from 11 AM Thursday to 10 PM PDT Saturday
CAZ070-071.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno