Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/14/22
Area Forecast Discussion
National Weather Service Grand Forks ND
1016 PM CDT Sat Aug 13 2022
.UPDATE...
Issued at 1016 PM CDT Sat Aug 13 2022
Upstream trends are lowering confidence in shower/thunderstorm
coverage in our area, and latest CAMs have slowed down
timing/coverage as well. I made adjustments to match this trend.
Elevated instability is limited in our CWA with mid level lapse
rates 6.5 C/km or lower and latest RAP favors similar conditions
air mass persisting. Considering this, I adjusted mention of
thunder to just our far western CWA as signal at this time just
favors mainly light pockets of showers/sprinkles if activity does
develop. Signal for light fog while still in place is still very
spotty in our MN counties and while Td depressions are much lower
impacts would likely be limited to just patchy ground fog as
drier air is not far off the surface.
UPDATE Issued at 641 PM CDT Sat Aug 13 2022
Surface high pressure is still gradually shifting east and as the
next weaker wave moves in from the west and mid-high clouds
increase there could be enough clearing still in our northwest MN
counties (maybe the southern RRV) for patchy ground fog
development. I didn`t adjust PoP timing in our west, but I did add
a mention of patchy fog to our east for now.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 314 PM CDT Sat Aug 13 2022
Impacts and challenge to the forecast will be coverage or
southeastward extent of shower activity overnight into Sunday
morning as precip encounters drier more stable air. Skies will
continue to gradually clear this evening before an increase in
coverage along the Int`l Border and Devils Lake basin as a weak
or subtle impulse in the mean 500mb flow brings an isolated storm
or shower after midnight or towards morning into the northern
valley. Any shower or storm will be small and rather quick moving
so amounts will generally be a tenth of an inch or less. With the
southerly flow and increasing clouds not expecting the widespread
fog that we had this morning.
More sun tomorrow with highs a bit warmer than today, in the 80
to 85 range. Sunday night another round of shower and storm
changes, once again in the 20 to 30 percent range for eastern ND,
as a weak wave approaches. Light amounts are again expected with
most remaining dry and possibly a tenth where precip occurs.
.LONG TERM...(Monday through Saturday)
Issued at 314 PM CDT Sat Aug 13 2022
The extended period covers from Monday through Saturday. Upper level
ridging begins to flatten and become more zonal over the Northern
Great Plains Sunday into Monday. Agreement between the ensembles and
models signal the most impactful weather will occur Monday evening
through Tuesday morning. Increased moisture and CAPE with a change
in flow pattern increase confidence that showers and possible
thunderstorms will occur however the amount of precipitation is
still uncertain. The Devils Lake Basin and the Northern Red River
Valley are the areas most likely impacted determined by the Skew-Ts
depicting rain profiles.
Thursday into Friday, the models are showing a low pressure system
beginning to form over the North Dakota/central Minnesota area. CAPE
levels are increasing for the Red River Valley creating a signal for
isolated rain showers. The ensembles also reflect this signal for
the possibility for the occurrence of rain showers. There is
uncertainty as to where the areas most likely impacted are. The PWAT
for region is also a little less than preferred to increase
confidence for rain showers.
The temp structure during the time frame will be fairly consistent
with near average readings. The multi-run ensembles and the NBM
Box and whisker plots puts the daytime highs in the low to mid
80s, dropping a bit by the end of the week. Overnight lows are
progged to range from the mid 50s to low 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 641 PM CDT Sat Aug 13 2022
VFR conditions are prevailing at TAF sites across eastern ND and
northwest MN and this is likely to continue for most sites through
the TAF period. There is a low probability for MVFR vis/status at
KBJI as surface high pressure will linger long, but current
guidance favors this further south and east and at most it would
patchy/shallow in nature. Scattered showers and isolated
thunderstorms may develop into the Devil Lake Basin after 06Z
possibly into northeast ND before ending before daybreak (based on
latest timing). Wind will tend to be light through the night,
increasing from the south 10-15kt during the daytime period Sunday
as low pressure begins to deepen to the west.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...DJR
SHORT TERM...JK
LONG TERM...MM/CJ
AVIATION...DJR
Area Forecast Discussion
National Weather Service Grand Junction CO
546 PM MDT Sat Aug 13 2022
.SHORT TERM...(Tonight through Sunday night)
Issued at 229 PM MDT Sat Aug 13 2022
Little has changed in the short term with high pressure centered
over the Oklahoma Panhandle dominating the weather pattern over the
region and the main thrust of the monsoonal flow just to the west of
the area from central Utah to eastern Nevada. Satellite imagery
confirms the model initialization with the cutoff low that has been
hanging around off the coast of the Pacific Northwest has been
picked up in the storm track and ejected northeast into British
Columbia. Initial observations of the sky late this morning as the
cumulus started popping indicated little, if any convective
inhibition with towering cu seen in all directions from KGJT. This
mornings sounding again had the PWat slightly above one inch
indicating plenty of moisture to support convective activity and
with forecast diurnal heating, free convective potential up to about
200 mb. The initial convective activity is confirming this lack of a
cap. The steering flow aloft is almost non-existent with the early
convection nearly stationary, increasing the risk for heavy rain
leading to localized flash flooding. Lightning activity is much
stronger today than the past couple days with more ground strikes,
also indicative of deeper convection. The HRRR and HREF are an hour
or two behind on initiation while the WARF errors on the aggressive
side as usual. Satellite shows an MCV south of the Great Salt Lake
that is drifting eastward towards the Uinta Mountains and the CAM`s
prog it to be a player this evening in northeastern Utah and
southwestern Wyoming. The CAMs are forecasting convection lasting
through the evening tonight with a few nocturnal storms continuing
into Sunday morning especially across the northern area.
Most models have picked up on a stronger MCV in northern Arizona
today, moving it up into northeastern Utah and northwestern Colorado
Sunday into Sunday night. Should it drift farther east, it could
become a big player for the Moab area in eastern Utah northeast to
the Park Mountains in Route County. In general, Sunday looks to be
the most active day with widespread showers and thunderstorms over
the higher terrain of eastern Utah, and central and northern
Colorado. Look for isolated to scattered storms in the lower
valleys. The southern areas will see somewhat drier conditions as
the plume of moisture remains to the north. With increased daytime
cloud cover and the more precipitation in the central and northern
areas, will see temperatures cool about five degrees with only
slightly warmer temperatures in the drier southern areas.
.LONG TERM...(Monday through Saturday)
Issued at 229 PM MDT Sat Aug 13 2022
Deep monsoonal moisture will remain in place as high pressure
remains to our southeast over eastern New Mexico and the Texas
Panhandle, with another high pressure ridge situated over the Great
Basin. Even though conditions appear to dry out across the
Intermountain West, this favorable southerly flow will allow this
deep moisture plume to surge from central and eastern Arizona into
eastern Utah and western Colorado. PWAT anomalies will increase as
this deep moisture plume shifts eastward from the Great Basin over
the western slope, with values in the range of 160 to 220 percent of
normal. In addition to the deeper moisture, remnants of a shortwave
trough will continue to track across the north, allowing for more
robust convection on Monday. As this trailing shortwave trough dives
southeast, it will suppress the high to our southeast and shift
convection into southwest Colorado through the late afternoon and
evening hours on Monday. Although it`s hard to pinpoint exact areas
of deep convection, Monday looks to be a very active day with
widespread showers and thunderstorms, favoring the mountains
initially with drift into lower valleys late afternoon into the
evening hours and redevelopment over some valleys as outflow
boundaries interact. Deep moisture is still in place, so the added
benefit of a robust shortwave disturbance will enhance convection
with potential for heavy rain and localized flooding as many areas
are already saturated. Burn scars will be watched closely as well.
By Tuesday, the northern Great Basin high will try to push some
drier air in across the north, keeping the deeper monsoonal moisture
for the central and southern areas. This pattern continues through
Wednesday with moisture continuing to be recycled each day and no
discernible features moving through under this high. The focus
for afternoon/evening convection appears to be the central and
southern mountains and adjacent valleys for Tuesday and Wednesday
with northern areas experiencing a bit of a downturn in terms of
storm coverage.
An interesting change seems to occur Thursday as a low pressure
trough moves onto the northern California coast and progresses
inland across the northern Great Basin, getting caught underneath
the ridge of high pressure. A bit of a Rex Block forms over northern
Utah late Thursday into Friday, with this low being absorbed by
upper level flow and pushed southward next weekend. Kind of a
complicated setup with no real focus for best areas of convection,
but moisture appears to move in with this low pressure with more
monsoonal moisture being drawn up from the south across the Four
Corners with our CWA largely remaining in a deformation area between
these features. In simple terms, if you can simplify this, moisture
looks to increase Thursday through Saturday with more scattered to
widespread storm activity across much of the area and potential for
convection to rumble through the overnight hours. Heightened
potential for heavy rain and localized flash flooding over prone
areas looks probable with a slow drying trend perhaps late next
weekend as northerly flow hopes to drive this embedded low and
moisture south again. Temperatures through the coming week into next
weekend appear to stay near to a few degrees below normal with
continued moisture in place and resultant daily storm activity.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 542 PM MDT Sat Aug 13 2022
Some convection continues this evening but has become more
isolated in nature. Kept VCTS for KMTJ and KTEX for the next few
hours. Overnight, a few showers will remain possible but don`t
anticipate any occurrences at TAF sites. Expect more activity
tomorrow afternoon and becoming more widespread. Gusty outflow
winds to 40 kts are possible with storms as well as heavy rain.
This heavy rain may drop airfields to MVFR albeit very briefly in
the afternoon and evening hours. Included VCTS for mountain TAF
sites as confidence remains highest there, all after 18Z
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Flash Flood Watch until 10 PM MDT this evening for COZ008-010-
013.
UT...None.
&&
$$
SHORT TERM...DB
LONG TERM...MDA
AVIATION...TGR
Area Forecast Discussion
National Weather Service Jackson MS
947 PM CDT Sat Aug 13 2022
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
An increasingly diffuse frontal boundary remains draped across the
area with the main delineation being low 70s to upper 60s
dewpoints and drier air across the northern half of the CWA with
mid 70s dewpoints along and south of I-20. PWs are below 2" across
the area with 2" or greater amounts confined to the Gulf Coast.
Dry air above 700mb, per the 00z JAN sounding, resulted in dry air
entrainment of convective updrafts this afternoon with coverage of
diurnally driven activity much more isolated. As of this writing,
a lone shower remains across east central Jasper County, but will
likely dissipate shortly after AFD issuance. For the remainder of
the evening, mostly clear to partly cloudy skies are expected with
temperatures dropping into the mid to upper 60s north of I-20
with low 70s along and south. Patchy fog may develop across the
Pine Belt along with a scattered low stratus deck, but widespread
fog is not anticipated. The ongoing forecast remains on track and
only minor changes to PoPs were needed. /TW/
Prior discussion below:
Tonight and Sunday:
Tonight: Ridging is anticipated to build SE tonight, keeping NW flow
aloft & dry thermo profiles around overnight. The stalled sfc
frontal boundary will slowly lift back to the NE, keeping drier air
& dewpoints in the mid 60s to the N of I-20 while low 70s S of I-20.
Lows will fall near climo in the low 70s in the S half of the area
while cooler & below in the upper 60s to the N. With decreased rain
coverage today & limited coverage of fog this morning, some patchy
ground fog can`t be ruled out overnight but widespread fog potential
looks less likely. RAP or NAM isn`t as aggressive in density or
areal coverage as last night, so holding off any mention of patchy
dense fog.
Sunday: Near carbon copy of today is expected Sun as ridging & warm
thermo help most areas warm near or above climo into the low-mid
90s. Rain & storm coverage late aftn into the Hwy 84 corridor.
Little better heating & lapse rates could help some brief strong
wind gusts. Humidity won`t be a concern, but we could be muggy as
heat indices again climb into the upper 90s to low 100s. No heat
stress concerns are expected for the HWO. /DC/
Monday through Saturday:
The primary driver of the weather pattern for the new work week
will be a deepening upper-level trough over the eastern half of
the CONUS. The ridge that has been persistent over the Southern
Plains will translate westward over the Inter-Mountain West,
allowing for flow aloft to become more northwesterly by later in
the week. The lingering influence of the ridge and compressional
heating ahead of a southward-diving cold front will boost temps
on Monday into the mid-90s or so. We`ll get one more day of hot
weather before the front moves into the region, with peak heat
index values near or above 105 degrees for much of the area. There
will be a slight chance for showers and thunderstorms on Monday
with the disturbance moving into warm, unstable air.
For the rest of the week, the frontal boundary is expected to
waver across our region as the upper-level trough becomes
dominant and westerly flow sits over the Gulf Coast. Timing is a
little uncertain regarding shortwaves in the flow aloft, but there
are increasing chances for heavy rainfall Wednesday night and
Thursday night as the front dips south. Increasing westerly flow
in the low levels with any shortwave will be the focus for
potential training rainfall and high rain rates driven by PWATs
near 2.0 inches. Will monitor the trends for possible flash flood
threats later this week. /NF/
&&
.AVIATION...
00Z TAF discussion:
VFR conditions will prevail at all terminals through the TAF
period. Ongoing isolated showers will dissipate over the next
several hours. Patchy fog and scattered low stratus will be
possible during the early morning hours, especially at HBG/PIB.
Any fog/low stratus should quickly mix out/scatter by 14/14z.
Afternoon showers and storms will be isolated tomorrow with
confidence in coverage too low to warrant mention in the TAF at
this time. Winds will be light and out of the north/northwest.
/TW/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 72 93 73 95 / 8 10 2 21
Meridian 72 95 72 96 / 10 11 2 28
Vicksburg 72 94 73 95 / 8 7 1 16
Hattiesburg 73 93 74 94 / 19 24 4 25
Natchez 72 92 73 94 / 10 15 3 18
Greenville 69 95 73 96 / 1 3 0 16
Greenwood 69 95 73 97 / 1 3 0 17
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
TW/NF/DC
Area Forecast Discussion
National Weather Service Key West FL
1016 PM EDT Sat Aug 13 2022
.DISCUSSION...
Significant amounts of cirrus were spilling southward, left from
convection earlier this afternoon and evening over the mainland.
Temperatures were in the mid 80s with dewpoints in the lower to
mid 70s, with very light winds having backed out of the northeast.
The surface ridge was hard to discern, having fractured from
troughing off the southeast U.S. and resultant from strong
insolation over the peninsula earlier today. The evening sounding
looked similar to last evening in terms of lapse rates, with added
mid-level moisture bringing the calculated precipitable water near
2.0 inches.
Over the past 24 hours, the high-level trough northeast of the
Bahamas has begun to lift further out over the north Atlantic,
with the Northeast trough axis now east of the Carolinas.
Northerly flow was becoming better-established over the Florida
Peninsula with an upper high over the western Gulf.
Of the CAM guidance this evening, the HRRR shows an interesting
development over the Middle and Lower Keys, suggesting localized
convergence setting up should ocean-side winds veer back to the
east to southeast direction observed earlier today, bucking up
against increasing landbreeze northeast flow off the Everglades.
If true, this would develop a good round of showers and
thunderstorms near or just north of the Lower Keys after midnight.
NAM guidance also shows the veering over the Straits and simply
spreading Gulfside without sharpening the convergence...and
therefore not much more than isolated convection. Statistical
guidance seems to base any increase in rain chance with the onset
of veering east-southeast winds, mostly in the pre-dawn hours
closer to sunrise. Not sure if any good clues in any wind veering
may occur prior to midnight along the reef. No changes are planned
at the moment, but wind directions oceanside will be monitored
very closely over the next couple hours.
&&
.MARINE...
There are no watches, warnings, or advisories currently in effect
for the coastal waters of the Florida Keys. This evening, winds
were northeast to east less than 5 knots with the signifcant seas
observed at Satan Shoal, west-southwest of Sand Key were at one
foot. A weakened western Atlantic ridge axis will linger across
South Florida and the Keys for the next week. As a result, an
extended period of light to gentle breezes are expected for the
coastal waters of the Florida Keys.
&&
.AVIATION...
VFR conditions will prevail over both the KEYW and KMTH terminal
sites through 14/12Z. However, guidance has showers developing over
the Gulf waters and effecting Key West between 14/04-14/06Z. There
is high uncertainty in the location and timing of the possible
convection late tonight into the morning hours. Therefore, VCSH will
not be included in the TAF`s at this time but, may be required later
tonight or tomorrow morning. Near surface winds will be generally
from the east to southeast near 5 knots, but will at times become
light and variable.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...JR
Aviation/Nowcasts....TW
Data Acquisition.....DR
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Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
845 PM CDT Sat Aug 13 2022
.MESOSCALE DISCUSSION...
Issued at 845 PM CDT Sat Aug 13 2022
Severe threat has diminished, with only isolated thunderstorm
coverage likely remainder of late evening/overnight.
Surface low pressure was analyzed near the Quad Cities at 00Z,
with a cold front trailing through northern MO into far northern
KS. A warm front curved southeast and south of the low through
western IL into eastern MO. While a few convective attempts were
made along the front in eastern IA late this afternoon/early this
evening, the warm mid-level temps and resulting inhibition/capping
mentioned in the previous mesoscale update appear to have proven
too much to overcome. Farther east, elevated isolated to widely-
scattered showers have developed across northern IL in warm
advection/isentropic upglide above the warm frontal slope. AMDAR
aircraft ascent soundings from MDW at 0030Z/730 PM depicts
relatively poor lapse rates through the column, though some
shallow instability was noted above ~880 mb likely supporting
current showers. DVN 00Z RAOB (in the warm sector west of the
surface warm front) looked a little better, though sampled a warm
layer of +14C around 740 mb, with a fairly dry profile through and
above that level.
Given above, it appears that severe threat has diminished greatly
across the region this evening. While some increase in scattered
showers is likely across the area late this evening into the
overnight, thunderstorms look to be more isolated and likely along
the cool side of the surface warm front as it tracks east-
southeast across the cwa into the pre-dawn hours. Occasional cloud
to ground lightning, brief downpours and small hail will be
possible with these isolated storms.
Ratzer
&&
.SHORT TERM...
Issued at 301 PM CDT Sat Aug 13 2022
Through Sunday night...
Aside from a few widely scattered showers ongoing across parts of
northern IL, all is quiet across the area. This is likely to
change, however, as we head into this evening. Currently our main
area of focus is with an approaching surface cold front and
compact surface low. This front is located northwest of the area
over eastward IA into far southwestern WI, just northwest of KDBQ
and KCID. It is within this area that we will be monitoring for
the initial development of isolated to widely scattered
thunderstorms after 5 pm.
A narrow corridor of lower 70 degree dew points now resides
within the frontal boundary, and clouds have cleared across this
area, allowing temperatures to warm into the lower to middle 80s.
While satellite imagery current suggests capping remains in place
near the front, the expectation is that continued surface heating
over the next couple hours and modest height falls/cooling
associated with an approaching impulse will weaken convective
inhibition enough to support at least isolated storm development
late this afternoon after 5 pm over northwestern IL and
southwestern WI. Recent runs of the HRRR continue to support this
idea. Any storms that do develop with be capable of developing
rotating updrafts (super cellular structures) owing to enhanced
and veering mid level flow. Any such structures will increase the
threat for a few isolated instances of hail, and strong gusty
winds. Also cannot rule out a brief window in which a short lived
tornado or two could result with any of these surface base storms
early this evening given the veering low- to- mid level flow. The
window for such would be short lived, and primarily west of I-39.
Storm coverage is expected to increase over northern IL after
sunset this evening as Theta-E advection ramps up owing to an
increasing west-southwestern low-level jet. Storms will become
increasingly elevated after sunset, so the threat of tornados will
quickly subside. However, with the threat of some elevated
supercells, the threat for isolated instances of hail will
continue over eastern IL and into northwestern IN this evening,
along with heavy downpours. The main focus for storms is expected
to become focused across far eastern parts of IL and into
northwestern IN later this evening before shift east-
southeastward out of the area overnight. The primary time period
of possible strong storms will be from about 6 to 10 pm.
Winds will turn northerly and become breezy on Sunday in the wake
of the wave of low pressure shifting over the area tonight.
Temperatures will be on the cool side of average (low to mid 70s) as
lower cloud cover looks to hang on for a good part of the day. The
most notable concern is the likelihood of dangerous swimming
conditions developing along the northeastern IL shores due to
building waves on Lake Michigan. We have opted to issue a beach
hazard statement from late morning Sunday through Monday morning,
though onshore winds through the day Monday will continue at
least a moderate swim risk.
KJB
&&
.LONG TERM...
Issued at 301 PM CDT Sat Aug 13 2022
Sunday night through Friday...
No changes to the extended period this afternoon.
The extended forecast period features pleasant late summer weather
with seasonable to slightly below normal temperatures expected
through the work week. North to northeast surface winds will
limit warming near Lake Michigan to just the mid 70s. Further
inland can expect highs in the upper 70s to lower 80s. There are
occasional weak short-waves embedded within the northwest upper
level flow that move overhead through midweek but think dry
conditions should prevail for most areas under broad surface high
pressure. The eastern periphery of the western ridge will begin
to break down later in the week. Long-range guidance remains
varied in the handling of this. Will maintain blended slight to
low chances for showers/storms Thursday into Friday noting that
our dry stretch could persist. Either way it is not looking like
a wash out heading into the weekend at this range.
Petr
&&
.AVIATION...
For the 00Z TAFs...
Forecast concerns for the terminals...
*Chance for scattered showers and a few thunderstorms this evening
*MVFR ceilings move in behind the cold front late this evening and
linger through Sunday
*Breezy northeast winds Sunday afternoon
A broad surface low and associated cold front continue to
gradually push eastward across eastern Iowa this evening which
will eventually move through the terminals late this evening.
While nothing more than a few light showers/sprinkles has been
shown on radar so far, forecast soundings continue to show decent
elevated instability present across the area which would support
the development of a few thunderstorms this evening as the front
moves through. Given this possibility I have maintained a formal
TSRA mention at the Chicago terminals starting around 03z which
seems reasonable given the latest observational and guidance
trends. I did decide to go with a VCSH mention for RFD given its
close proximity to the cold front and the limited activity around
the terminal so far which is likely due to some remaining capping
aloft, however; the possibility is still there for an isolated
thunderstorm or two to develop near RFD prior to the frontal
passage around 04z.
Once the cold front moves through this evening winds will turn
northwesterly with speeds around 10 kts persisting through the
rest of the overnight hours. Winds will then become northeasterly
and increase in speed as the pressure gradient tightens behind the
surface low Sunday morning with gusts around 20 kts expected
Sunday afternoon. Ceilings will also be lowing to MVFR behind the
front overnight and are expected to linger throughout the day on
Sunday before gradual improvement begins to occur late Sunday
evening.
Yack
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ103-ILZ104...11 AM Sunday to
10 AM Monday.
IN...Beach Hazards Statement...INZ001...11 AM Sunday to 10 AM Monday.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744...11
AM Sunday to 4 AM Monday.
&&
$$
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Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1102 PM CDT Sat Aug 13 2022
.UPDATED for 06Z Aviation Discussion...
Issued at 1059 PM CDT Sat Aug 13 2022
&&
.DISCUSSION...(This evening through Friday)
Issued at 248 PM CDT Sat Aug 13 2022
KEY MESSAGES:
- Fog likely late tonight into Sunday morning and again Sunday night
into early Monday morning.
- Near and slightly below normal temperatures through the upcoming
week. The chance continues for several small rounds of
precipitation.
Tonight through Sunday Night...A slow-to-exit low pressure center
over far SE MN and SW WI in conjunction with a weak mid-level
shortwave trough within the northwest flow aloft has kept low
stratus clouds in place all day. While no precipitation has resulted
nor will result from this setup, is has kept optimum insolation from
reaching the surface, thus keeping afternoon temperatures down from
previously expected max temperatures. The cloud cover will generally
remain in place through the rest of the daylight hours, holding max
temperatures this afternoon in the 60s and 70s. This low pressure
center will shift away into the Great Lakes tonight, being replaced
by an area of high pressure dropping in from central Canada.
However, its orientation will maintain a weak east to northeast
surface flow overnight. The nightly inversion will trap low level
moisture in place near the surface. Even with partial clearing, the
setup is there to have appreciable fog coverage overnight tonight,
or at least in conjunction with low stratus should wind speeds be a
little bit higher than currently forecasted. Have added fog mention
into the gridded/text products. Not confident enough at this point
to mention dense fog (less than 1/4 mile) but that possibility
cannot be ruled out, especially in western WI. Any fog will
dissipate by late Sunday morning, making for another comfortable day
as highs are expected to run in the mid-upper 70s, maybe even lower
80s in central-western MN should enough sunshine be realized. High
pressure is expected to remain generally in place Sunday afternoon
through Sunday night, with little change otherwise in the synoptic
features across the area. Therefore, fog is again looking likely
across the WFO MPX coverage area Sunday night into early Monday
morning so have again added its mention into the gridded/text
products. Low temperatures both tonight and Sunday night will run in
the mid 50s to lower 60s.
Monday through Friday...The majority of Monday`s precipitation
should bypass Minnesota to the south and west as a disturbance just
barely misses us. It is not out of the question for some of these
showers to crawl into southern Minnesota should they be able to break
through the dry layers aloft. Beyond Monday, forecast models are
indicating more chances for PoPs throughout the week, but overall
timing and placement are still highly variable. Currently have low
confidence in significant rainfall at any one location this week and
medium confidence in the MPX CWA seeing some form of precipitation
every day this week (splattering of 20-40% PoPs every day). As the
days inch closer, we hope to have a better grasp on the atmospheric
setup and thus the precipitation chances and timing. Precipitation
chances aside, this week looks to have light winds and slightly below
normal temperatures as a very wide and weak pressure gradient
sprawls across the CONUS.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1059 PM CDT Sat Aug 13 2022
Low stratus is lingering across much of the region tonight, and the
question remains whether or not this will transition to fog later
tonight and Sunday morning, or if it will remain as MVFR to possibly
IFR stratus. Forecast soundings off the RAP show that low stratus is
more likely to the east at KMSP/KMKT/KEAU/KRNH, with fog likely to
the west, so tried to transition this way in the TAFS. VFR conditions
should return for Sunday.
KMSP...
Continues with the trend of more low stratus than fog overnight in
the TAFs, but could see some fog develop at KMSP if clearing
happens before sunrise. Winds will be light, and become more
easterly for Sunday.
/OUTLOOK FOR KMSP/
Mon...VFR. Wind SE 5-10 kts.
Tue...VFR. Wind SE 5-10 kts.
Wed...VFR. Wind S 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...JPC/PEM
AVIATION...JRB
Area Forecast Discussion
National Weather Service Topeka KS
550 PM CDT Sat Aug 13 2022
...AVIATION UPDATE...
.DISCUSSION...
Issued at 232 PM CDT Sat Aug 13 2022
Forecast Summary:
1. Heat indices today around 100 degrees across much of the area.
Tomorrow the focus area shifts to the southwestern areas.
2. A couple chances for rain into Tuesday and possibly again late
Thursday into Friday.
3. Cooling trend continues into next weekend starting Monday night.
More detailed forecast:
Currently, a deep trough is lifting through the New England region
with northwest flow into a broad ridge over the northern Rockies as
a semi-permanent anticyclone remains in place over the southern
Plains into the central Plains regions. Monsoonal moisture continues
to be drawn around the western flank of the anticyclone through the
Desert Southwest into the northern Rockies. Another Pacific system
is currently just off the coast of the Pacific Northwest region.
For today and tomorrow hot temperatures remain over much of the area
with heat index values today around 100 degree at most locations
even as low level moisture mixes out with air temps upper 90s and
low 100s. A weak boundary sags into the area overnight allowing for
some ares to cool into the upper 60s and low 70s. Sunday will be hot
again with most areas above normal into the upper 90s but areas on
the northeast side of the boundary remain near normal around 90. So
the focus for heat Sunday and even still holding on into Monday
becomes further to the southwest over north central into central and
portions of east central areas. Still expect most areas heat index
wise to to top out into the low 100s so no headlines planned at this
time.
Sunday morning could see a few early morning showers but this would
likely be very isolated and there appears to only be weak support
with weak isentropic ascent along the 310K surface for a brief
period of time but saturation doesn`t appear to be deep at all. The
HRRR model is still suggesting a weak band of showers develops early
and lasts through mid morning. Just beneficial rain for those who
get it but wouldn`t likely amount to much.
Into late Monday night and during the day Tuesday, a better chance
for precipitation looks more likely - mainly over northeastern areas
- with a sharp gradient further southwest across the area. As a
Pacific trough works through the northern Plains into the central
Plains, the ridge flattens and forcing for ascent increases mainly
over eastern Nebraska into Iowa and northern Missouri. Currently,
northeast KS appears to be on the southwestern flank of the best
forcing for ascent but H85 moisture flux and convergence does set up
over portions of northeast KS with high PWAT values from 1.50-2.00
inches. If storms can back build into the area, then high rain rates
could be in place for a few hours with relatively slow moving
storms. Can`t rule out some flooding but right now hard to determine
if the focus areas would be into northeast KS at all. Once this
moves through, a surface ridge begins building with another
shortwave perturbation working into the area late Thursday into
Friday. Right now the GFS appears to be the most aggressive solution
with the entire area seeing rainfall and storms for now. This time
frame does appear to have a high level of uncertainty with fairly
wide spread amongst the deterministic models at this time.
Overall, consistency in trending cooler than normal with
temperatures does appear to be consistent further into the upcoming
work week into next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday)
Issued at 550 PM CDT Sat Aug 13 2022
VFR conditions are forecast to persist. There is some concern for
ground fog as models pool slightly higher dewpoints north of the
weak boundary sliding south. However there are some mid level
clouds expected to overspread the area with overnight lows
remaining rather mild. With almost all guidance keeping
visibilities greater than 6SM, will monitor trends and keep the
forecast without restrictions.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Drake
AVIATION...Wolters