Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/04/19
Area Forecast Discussion
National Weather Service La Crosse WI
1048 PM CDT Thu Oct 3 2019
.SHORT TERM...(This evening through Friday)
Issued at 217 PM CDT Thu Oct 3 2019
At 2 PM, skies were mostly cloudy across the Upper Mississippi River
Valley. There were a few scattered showers being detected by
surface observations and very light radar returns. Temperatures
ranged from the mid-40s to lower 60s.
The 03.12z models continue to show that the clouds currently over
the region will dissipate late this evening. However, with the
models having a bias of clearing out clouds too fast, opted to be
much more pessimistic and kept skies mostly cloudy through Friday
morning. This is when the ridge axis finally starts to move east of
the area. Despite the clouds, low temperatures will become rather
chilly (ranging from the mid-30s to lower 40s) on Friday morning.
There may be some patchy to areas of frost in central and north
central Wisconsin. Thought about a Frost Advisory, but with mostly
cloudy skies opted not to do one at this time.
The low clouds should gradually dissipate during the late morning
and early afternoon. However, as this occurs, mid and high clouds
will move into the area ahead of the next system. High temperatures
on Friday will be mainly in the 50s.
.LONG TERM...(Friday night through Thursday)
Issued at 217 PM CDT Thu Oct 3 2019
The surface high and upper ridge axis will drift east of the area
heading into Friday night. Meanwhile a negatively tilted surface
low/upper trough will make their way into the Northern Plains. Our
area will remain between these two systems Friday night, with
developing return flow pulling a substantial amount of Gulf moisture
northward into the Upper Mississippi Valley again. Moisture
transport will increase locally late Friday night on the nose of a
low level jet, nudging PWATs back into 1 to 1.4" territory across
the forecast area for Saturday. As the intensifying surface low
lifts into northern Minnesota, it will drag a trailing cold front
through the forecast area Saturday afternoon-evening. The result
will be another round of substantial widespread rainfall for the
area. Rain is expected to arrive across southeast MN and northeast
IA by late Friday evening, spreading into Wisconsin overnight. Bulk
of the rain will progressively taper off from west to east through
the day on Saturday, largely ending by Saturday evening. Still
looking like very limited elevated instability, but wouldn`t rule
out an embedded storm or two. Still consistent model signals
pointing to the likelihood of rainfall around an inch or so across
much of the forecast area, likely heaviest along and north of I-90.
Looks like less rainfall down towards Grant County, which is good
news given recent flooding issues there. Regardless, will need to
keep an eye on this system as the area recovers from recent heavy
rainfall.
Deep cyclonic flow will then linger through Monday as a longwave
trough drops through the eastern CONUS. This may result in spotty
light showers or sprinkles at times across Taylor/Clark counties on
Sunday and Monday, but ridging aloft and at the surface will quickly
build into the region by Monday night into Tuesday. An expansive
surface high will quickly grow to dominate most of the eastern CONUS
by midweek, but its influence here will be declining as its center
shifts to over the Northeast. Will have to watch for isolated light
shower potential by Wednesday as weak shortwave energy arrives with
an increasingly moist airmass. Models are coming into agreement with
another system dragging a cold front through the region next
Thursday with more widespread rain.
Temperatures will remain fairly seasonable through the period with
highs generally in the 50s/60s and lows in the upper 30s to 40s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1048 PM CDT Thu Oct 3 2019
For the most part, the low clouds have remained over the region
this evening. The exception is over eastern Wisconsin where a
rather large hole in the clouds has developed. Satellite imagery
indicates this is moving to the south for the most part but there
is some slow westward expansion of the clearing. The 04.02Z RAP
does show reduction in the 925mb moisture over the eastern part of
the state but does not bring is west over either airport. Plan to
keep both sites in the clouds until Friday morning with MVFR
ceilings. The clouds should then break up once the low level
ridge axis moves over the area allowing VFR conditions for much of
the day. The next system will quickly advance toward the area
Friday evening and spread a mid-level VFR ceiling back over both
airports. Rain from this system, along with more MVFR conditions,
looks to hold off until after 05.06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Boyne
LONG TERM...Kurz
AVIATION...04
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
848 PM CDT Thu Oct 3 2019
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...The 500 mb inverted trough that brought the afternoon
conv to the RGV this evening will continue drifting steadily
westward tonight into Fri. The afternoon and early evening conv
has died down with the loss of the afternoon heating. However, the
00Z BRO sounding shows a pretty unstable and tropical airmass in
place over the region with a PWAT of 2.11 inches and an MUCAPE of
3795 J/KG. The RGV airports will likely remain free of the conv
over the next few hours. However, expect the conv to refire later
tonight into early Friday morning as per the latest HRRR conv
guidance which appears to have initialized pretty well on the
recent conv. Will go with general VFR conditions over the upcoming
24 hours with some periodic reductions to MVFR conditions due to
the sct passing conv.
&&
.PREV DISCUSSION... /issued 341 PM CDT Thu Oct 3 2019/
SHORT TERM (Tonight through Friday Night): Upper low currently
centered southeast of the CWA will continue to moves slowly
northward tonight and Friday. This feature will contribute to the
overall unsettled synoptic pattern which has persisted all week
across Deep South TX and the Rio Grande Valley. An uncapped very
moist airmass will once again contribute to scattered to even
numerous showers and thunderstorms through Friday. Higher POPs
will be indicated further east closer to the upper low, higher
moisture, and better boundary layer forcing. As the upper low
begins to get sheared apart on Friday night, the convective
activity is expected to become less widespread. As a result, will
drop off rain chances significantly, especially west of I-69C, for
Friday night. Despite the increased rain chances and higher cloud
cover, temps will still be overall slightly above normal.
Long period 3-4 ft swells along with high astronomical October tides
will produce minor coastal flooding again tonight. This will
coincide several hours before and after high tide which is just
after 04Z Friday. As a result, issued a coastal flood statement for
the entire lower TX coast.
LONG TERM (Saturday through Thursday): Once again today...the
difficulty of the long term forecast lies in how models are
handling the wind shift/front early next week. The ECMWF remains
more bullish on the push of cooler air which leads to a stronger
surface ridge punching down across the eastern Rockies into the
Texas Panhandle by early Monday...at 1030 mb...while the GFS is
both weaker (1025 mb) and more east-west in its
orientation...which allows it to quickly scoot east with more of a
bridging effect for the impacts to be less of a true "front" and
more of a slight reduction in heat back to or a hair above normal.
Interestingly...the drier ECMWF pushes both lower dewpoints and
higher daytime temperatures (given dry to super-adiabatic mixing)
while the GFS has a bit more moisture as well as rain chances
which keeps temperatures near average (upper 80s by day, upper 60s
by morning or most). Until the situation clears up...have
continued to blend forecast data but the lean here is toward the
GFS simply because the upper level and strength of the surface
high/source region is not sufficiently strong enough for a full-on
sweeping front next week.
For the sensible weather, then...the developing of flat 500 mb
ridge to our west and northerly flow between it and the weakness
nosing into the southwest Gulf will both shove deeper moisture
into northeast Mexico and keep the surface low pinned in the Bay
of Campeche. This will maintain a weak extension of the surface
high from the U.S. east coast through east and southeast Texas,
with light east/east northeast flow across the region under a mix
of sun and clouds. Low to silent rain chances (20 to 10 percent)
is the best bet...though could see a little action near South
Padre early Saturday before lower coverage arrives by afternon.
Temperatures will be able to recover back to the low to mid 90s in
most areas with the increased sunshine/minimal coverage of showers
each day.
By Monday...the bridging ridge will move across the southern
Plains with ridge axis extending through the Valley...and with the
blended solution this picks up northeast to north winds to the
breezy side near the coast but only a fresh breeze farther inland.
Some deeper moisture associated with shear axis combined with
enhanced low level moisture from strengthening northeast flow off
the still very warm Gulf, have maintained the 30-50 percent
chances coastal/Gulf but trimmed back to slight chances farther
west. For Tuesday through Thursday...maintained the blended
forecast which sees winds slowly veer from northeast to
east/southeast and enough dry air filter in to lower dewpoints a
shade, especially along and west of I-69C, and split the
difference on afternoon highs which will still be 2 to 3 degrees
above average for the dates (October 8-10). Morning lows will
finally drop...but may remain above 70 along/east of US 77/IH 69E
and could struggle below that even in rural areas of the Valley
and King Ranch.
Hopefully...we`ll have a better consensus on how this will play
out this time Friday.
Two key hazard to continue to monitor is for beachgoers. Swell
period has picked up to 8 seconds today and expect this to
continue through the weekend, per gradient from weakening east
coast ridge and the broad low pressure from the Bay of Campeche to
the northwest Caribbean. Rip currents will range from moderate to
high intensity, focused at Isla Blanca park, while waves
themselves will remain inviting as heights hold in the 2 to 4 foot
range overall. Tidal "run up" will continue as well, and may
encroach the dunes at overnight high tides after midnight Saturday
and Sunday night. The good news? Tidal ranges are among the
highest we see, and by midday are expected to be near the zero
line above mean higher high water, which is generally the point
at which foam reaches one`s toes. That said, enhanced wave `set
up` with the persistent swell period should allow a bit more water
than usual to run up during low tide, so all beaches will still
narrow a bit even by day...but not enough to force people to set
up equipment behind the dunes when the beaches are crowded.
Bottom line? Expect rip current statements at some point through
the weekend, with coastal flood statements and perhaps an advisory
to cover the high tide rises overnight.
Beyond the weekend, additional run-up is likely as the gradient
and fetch pick up further, with the potential for 9-10 second
swell periods and high waves offshore running onto the beach.
Advisories and continued high danger rips may be common Monday
through Wednesday.
MARINE: Tonight through Friday night...Incoming swells due to a
long fetch of moderate east- northeast flow will keep seas
generally in the 4 foot range through Friday. Gradient flow will
keep conditions below caution or advisory levels. Rain chances
will be the highest over the waters given the uncapped and higher
moisture atmospheric profile.
Saturday through Tuesday Night...The big story is the wind
shift/potential front and strength of the high pressure behind it.
That comes Monday and continues into Tuesday. For the weekend,
light winds and moderate seas (courtesy of the swell) will
dominate, and rain coverage should be lower than in recent days so
overall not a bad time for boating/fishing since swell will be
more dominant than wind waves and seas should be 3 to 4 feet
overall.
By Monday, that changes, with northeast winds approaching small
craft advisory conditions and seas likely responding to a
combination of wind and east/northeast fetch with the tighter
gradient. WaveWatch4 does not handle this situation as well, so
blended with TAFB and have seas up to 6 feet in the offshore
waters and 5 feet elsewhere for Monday through Tuesday morning
before slowly subsiding later Tuesday into Tuesday night. Small
craft exercise caution may be required for this period (Monday-
Tuesday night) due to seas alone.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
Short Term/Aviation...60
Long Term/Upper Air/Graphicast...67
Area Forecast Discussion
National Weather Service State College PA
1117 PM EDT Thu Oct 3 2019
.SYNOPSIS...
A frontal system will will pass through the region tonight.
After a cooler day tomorrow, many areas will see their first
frost on Saturday morning. After that look for a dry weekend
with moderating temperatures. Wet weather will return early next
week as a new frontal system moves our way.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Meso anal shows a very complex frontal system moving across the
area. As of 10PM the front is just west of Wellsboro down to
just about overhead State College into VA/ND east of Bedford.
Radar shows just a couple of very light leftover showers over
my SERN zones and given upstream trends, I generally sliced a
bunch off the overnight post frontal POPs.
The latest RAP and HRRR suggest this complex front will
continue east this evening, clearing my SERN zones around or
shortly after midnight.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Post frontal weather tomorrow with cooler and drier air. Any
clouds will dissipate through the day, leaving most places clear
by sunset. Maxes only in the u40s over the hilltops of the
north, but in the m60s in the south...about 5 to 10 degrees
below normals.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
The medium to long range period will be highlighted by a fairly
progressive northern stream flow across the northern U.S. and a
trend toward more normal to slightly below normal 500 mb heights
and 850 mb temps.
Leading off the period, the first significant Frost/Potential
Freeze will occur across the Northern mtns of PA late Friday
night through sunrise Saturday as a 1032 mb sfc high slides by
just to our north. A Freeze Watch was recently posted for 3 of
our northern tier counties from 06Z-13Z Sat, with min temps
expected to average 32-34F, though some of the typically
colder, high mountain valleys could see mins of 29-30F.
As the high slides off the New England Coast Saturday afternoon
and night, a rather strong llvl p-gradient will develop across
the CWA with a gusty south to SE flow developing. Abundant
sunshine will try to balance out the chilly temps Saturday. Mid/high
level clouds will be increasing from the west pretty quickly
Saturday night, within an area of increasing WAA and at the
leading edge of an area of approx plus 2 sigma PWAT air ahead
of a potent upper trough.
Conditions will likely stay dry across most or all of the
western zones through daybreak Sunday, before numerous showers
spread across the NW half of PA during the day. Showers will be
more scattered and favor the afternoon and nighttime hours
Sunday across the Lower Susq Valley. Most model guidance
indicates a backing upper flow with the region becoming located
beneath a pronounced Jet Entrance Region Sunday night through
Monday. This will likely greatly slow the CFROPA or temporarily stall
out the boundary across PA with a moisture laden, albeit weak
wave of low pressure lifting NE from the Ohio River Valley
through PA.
This will bring a widespread, soaking stratiform rain to start
the week with GEFS 24-hour QPF expected to average between
0.50-1.00 inch. However, low GEFS probs of 2+ inches/36 hr and
EC storm total QPF in the 1.5-2 inch range across the northern
mtns suggests that some minor ponding/sharp rises on small
streams could become a notable impact by Monday.
The Tues-Thu period of next week contains a fairly high
confidence for dry weather with mostly sunny days with
slightly below normal temps in the 50s/60s, and fair, chilly
nights in the 30s/40s.
The next chc of showers will arrive sometime Friday based on a
blend of the EC/GEFS and NBM.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Large area of IFR and MVFR conditions associated with low cigs
and even some lower vsby across a good portion of the area.
Frontal system will push through the area later tonight with
improving conditions. Mainly VFR tomorrow with much better
weather.
.Outlook...
Fri...Gusty NW winds. AM low cigs possible NW Mtns/Laurels.
Sat...Patchy AM fog possible.
Sun...Rain/low cigs possible, mainly N Mtns.
Mon...Rain/low cigs possible, mainly W Mtns.
Tue...Improving conds esp during daylight hours.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Freeze Watch from late Friday night through Saturday morning
for PAZ005-006-037.
&&
$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...Ross
LONG TERM...Dangelo/Lambert/Evanego
AVIATION...Ross/Gartner
Area Forecast Discussion
National Weather Service Goodland KS
830 PM MDT Thu Oct 3 2019
.UPDATE...
Issued at 825 PM MDT Thu Oct 3 2019
GFSLamp, Rap13, HRRR model runs are in excellent agreement
producing visibility reductions in fog starting around 10z and
lasting through 15z or 16z for locations north of a warm
front...Wray to Colby and Gove southward. Have updated the
forecast to introduce areas of fog and HWO to mention threat of
dense fog. With the increase in cloud cover and dewpoints from
increasing southerly winds I`m a bit concerned the overnight low
temperature forecast may be too cool. Will evaluate latest model
data but have trended min temps up just a bit from previous
forecast.
Strong south winds are expected Friday with gusts to 45 mph along
and west of the CO/KS border. Dust dispersion models do not show
any signs of a blowing dust threat. This may be partially due to
the relatively high surface relative humidity and fairly low
(stable) 0-2km lapse rates.
&&
.SHORT TERM...(This evening through Friday)
Issued at 200 PM MDT Thu Oct 3 2019
Old front has stalled against the Front Range, but will gradually
return eastward as a warm front tonight and Friday as a large
upper trough moves across the northern Rockies. Clouds will
gradually increase from the south tonight, as do surface winds,
which will keep low temperature in the middle 40s. Precipitation
chances will begin to creep back into the far southeastern
counties overnight. Precipitation will be very light, but there is
some low MUCAPE forecast so decided to add a mention of thunder.
Friday will start out mostly cloudy over the entire area, then
some partial clearing in western areas on the warm side of the
front. Eastern areas will be cloudy all day and cooler. So, there
will be a rather large east to west temperature gradient, with
highs ranging from the upper 50s east to upper 70s west.
Precipitation chances will continue, mainly in the east in the
morning, then another batch of showers/thunderstorms in the
afternoon as the main upper trough ejects into the central and
northern High Plains. Best forcing will remain north, so expecting
only scattered coverage. Weak instability is forecast in the
afternoon in northeast Colorado and along the Kansas border area
by the more aggressive CAMs (1000-1500 j/kg), and fairly decent
deep layer shear of around 40 kts, so cannot totally rule out an
isolated severe threat for marginally severe hail/wind, but with
the combination of weak instability/weak forcing the probability
is rather low. It will be windy, with south winds 20-30 kts and
higher gusts by the afternoon. Precipitation chances will move out
to the east through Friday night with gradual clearing. Low
temperatures will be in the 40s and 50s.
.LONG TERM...(Friday night through Thursday)
Issued at 228 PM MDT Thu Oct 3 2019
Forecast concerns will be colder low temperatures into Monday
morning, and winds/fire weather on Saturday. Satellite showing an
amplified but still progressive flow from the Pacific into eastern
North America. Upper trough over the western portion of the country
with ridging over the east.
Saturday/Saturday night...Dry conditions expected. Strong upper jet
moves across the area in the morning into early afternoon. The day
will begin with a strong cold front just having just cleared the
area. Pressure gradient and 3 hour pressure rises would indicate
windy conditions. There looks to be some decent downward motion in
the afternoon. The Gfs is mixing down stronger winds, and get close
to warning criteria. However most of output fits with the previous
forecast of near 45 mph gusts. This and collaboration with neighbors
led to using Consmos for winds.
It looks like the winds start decreasing early in the afternoon as
the surface ridge starts moving into the region. Forecast blend
maxes look reasonable. For the affects of this on Fire Weather,
refer to that section below.
The winds become light during the night, especially in the eastern
portion of the area. Right rear quadrant of the upper jet moves
across during the night. Models are indicating some mid to high
level cloud cover which could slow the cooling. Mos output/some
consensus output support going lower than the forecast blend. Model
certainty output led me to lower the blend a few degrees but
potential there for more cooling. At the very least some frost is
expected.
Sunday/Sunday night...Dry conditions expected. Right rear quadrant
of the jet moves across during the morning. At the beginning of the
day it looks like a reinforcing shot of cold air arrives which
causes breezy to windy conditions. Again forecast blend maxes look
reasonable.
Winds drop off again during the night. However they do not look as
light as models shift the winds around faster. After looking at
model certainty output, I lowered the lows again more frost
occurring.
Monday through Thursday...Deterministic output starts out in good
agreement and then become increasingly different by the end of the
period. This primarily has to do with how the models handle the
northern system in both speed and amplitude.
Fast west to northwesterly flow aloft and dry conditions looks to
be prevail into Wednesday. Then in some form or other the above
mentioned trough move across. General consensus is the bulk of the
lift and chance of precipitation look to be to the north of the
area. So the slight chance pops the forecast blend gives me looks
reasonable. Also precipitation looks to be ongoing when
temperatures get cold enough for some light snow in northern Yuma
County Wednesday night. Little if any accumulation expected.
Due increasing model disagreement, am leaving temperatures alone. If
current forecast blend is close, widespread temperatures in the 30s
look to occur Wednesday and Thursday nights.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 450 PM MDT Thu Oct 3 2019
Sub vfr cigs move north reaching KGLD around 06z and KMCK near 12z
with winds from the southeast at 7 to 15kts (highest at KGLD).
Could see some mist as well at KGLD toward 12z. Cigs improve to
vfr at KGLD around 20z or so while remaining sub vfr at KMCK as
the axis of low level moisture lifts northeast. South winds
increase at KGLD with gusts over 35kts expected. At KMCK southeast
winds gusting over 30kts expected during the afternoon hours.
&&
.FIRE WEATHER...
Issued at 228 PM MDT Thu Oct 3 2019
Dewpoints look to remain low into the afternoon. However the winds
look to be lower in the afternoon than in the morning. Relative
humidities are 15 to 20 percent in eastern Colorado. However that
is when the winds are the lightest there. So it appears that
conditions will not be near critical. If the timing of the front
would slow down then there would be a better combination of stronger
winds and low relative humidities.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...024
LONG TERM...BULLER
AVIATION...99
FIRE WEATHER...BULLER
Area Forecast Discussion
National Weather Service Marquette MI
750 PM EDT Thu Oct 3 2019
.SHORT TERM...(This evening through Friday)
Issued at 317 PM EDT THU OCT 3 2019
Mid-upper level trough axis over the Upper Great Lakes as noted on
water vapor imagery and RAP analysis will shift east later this
evening. Forcing associated with the trough should also shift
east by this evening as any remaining rain showers will likely be
attributed to pure lake effect convection as temps at top of 4-5
kft convective layer will be -3 to -4c resulting in a lake delta-t
of around 17C. Convergent low-level northerly flow will help
focus lake effect rain bands into the higher terrain of west and
north central Upper Mi this evening.
Late tonight into Friday, increased ridging and associated lowering
of the subsidence inversion to 2-3 kft from the west overnight into
Friday should help bring to an end to isolated lake effect rain
showers over the western higher terrain late tonight and over the
north central higher terrain by early Friday. Otherwise, mid
level and sfc ridging building into the area should bring partial
clearing and slightly warmer conditions to the area. Diurnal cu
could still linger, especially over the higher terrain of north
central Upper Mi favored by upslope ne flow, as 850 mb temps fcst
to be 2-3C.
Look for min temps tonight ranging from the mid 30s interior west to
the lower 40s near the Great Lakes. Expect highs Friday generally in
the lower to mid 50s.
.LONG TERM...(Friday night through Thursday)
Issued at 448 PM EDT THU OCT 3 2019
Over the next 7 to 10 days, a typical progressive fall pattern will
prevail, featuring two trofs that will swing across the northern
CONUS. The first will reach the western Great Lakes late this
weekend and the second Thu/Fri next week. As would be expected under
a progressive regime, temps will fluctuate btwn above and blo
normal. Right now, it does not appear that daily temp departures
from normal will be significant. As for pcpn, the first trof will
feature a vigorous shortwave lifting across the northern Great Lakes
Sat night, likely providing a period of shra Sat/Sat evening. This
wave will also be a wind maker, gales for Lake Superior and likely
wind advy for the Keweenaw. Trailing shortwave moving thru the trof
will keep sct shra around into Mon. Dry weather should then prevail
Tue/Wed. Next approaching trof will bring shra back into the fcst
for Thu/Fri.
Beginning Fri night, with mid-level ridge over the Upper Great Lakes
and associated sfc high pres over eastern Lake Superior early, the
evening will start quiet. In advance of the shortwave trof
approaching the western Plains, developing waa/isentropic ascent
across the northern Plains will lead to high clouds spreading
downstream and across the fcst area during the night. However, it
looks like the increase in high clouds will be slow enough to allow
for a potential widespread frost across the interior central and
east. That said, there is one complication, and that would be the
possibility of lake clouds developing/spreading off Lake MI under
developing light se winds. Late in the night, leading edge of 850-
700mb moisture transport and isentropic ascent may reach the far w
toward 12z. So, -shra may arrive there near sunrise.
As upstream shortwave moves to the Upper Mississippi Valley by Sat
evening, 45-50kt low-level jet translates to the Upper Lakes along
with a good push of 850-700mb moisture transport and deep layer
forcing per q-vectors. Thus, expect shra to spread across the fcst
area from w to e during the day on Sat. Not out of the question that
there could be a rumble or two of thunder, but instability is really
lacking for tsra.
Shra will end Sat evening as cold front passes and mid-level dry
slot arrives. With cyclonic flow and the edge of deeper moisture
brushing the nw fcst area, there could be a few -shra thru the night
across nw Upper MI. Otherwise, main concern will shift to wind for
Lake Superior and the Keweenaw. Favorable aspects for stronger winds
are shortwave briefly taking on a negative tilt as it swings across
the area, favorable isallobaric wind component (though pres
rise/fall couplet is not especially notable at roughly +4 and
-5mb/3hr), and upwards of 45kt in the mixed layer. Negatives are
lack of strong caa as 850mb temps only fall around 4C, and for the
Keweenaw, low-level winds are more of a wsw direction rather than
the more favorable wnw direction. At least for now, looks like a set
up for a wind advy (sustained winds of 30mph or more and/or frequent
gusts 45mph or greater) for the Keweenaw Peninsula overnight Sat
night thru at least Sun morning. It is noted that the last couple of
GFS runs have showed 4-5hrs with potential to mix to 55kt winds over
the Keweenaw. Will be something to monitor for a potentially higher
impact wind event. With gales on Lake Superior, large waves may lead
to some lakeshore flooding/erosion issues around the w side of the
Keweenaw on Sun. Elsewhere across the fcst area, expect breezy
conditions on Sun with gusts to 30-35mph or so. Cyclonic flow/cold
air aloft may support isold -shra on Sun. Trailing shortwave passing
late Sun night/Mon morning will then maintain isold/sct -shra thru
Sun night into mainly Mon morning.
Dry weather will follow Tue/Wed as mid-level ridging passes. Expect
warming as well as sw low-level flow takes hold. Wed should be the
warmest day of this fcst period with high temps potentially well
into the 60s. Next trof will shift across the western Great Lakes
late Thu/Fri, bringing a period of shra.
&&
.AVIATION...(For the 00Z TAFS through 24Z Friday afternoon)
Issued at 750 PM EDT THU OCT 3 2019
Northernly flow from Lake Superior will persit through the evening,
bringing IFR conditions to all sites. KIWD and KSAW will
occasionally see LIFR conditions before the cloud base lifts. By mid
morning, all sites should be MVFR with continued lifting after that
thanks to an incoming ridge. Northern flow will also bring scattered
lake effect rain showers to all sites as well. As the ridge settles
in, expect winds to be light to VRB at all sites. &&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 317 PM EDT THU OCT 3 2019
Northerly winds of 15 to 25 knots this evening will relax blo 20
knots late tonight into Friday. Light and variable winds are still
expected by Friday afternoon as fairly strong high pressure moves
overhead. Southerly winds increase ahead of the next low pressure
system, with a good bet for southerly gales to 35 knots over the
east half of the lake ahead of the system late Saturday with
widepread sw-w gales to 40 knots behind the system for late Sat
night into Sunday. West winds diminish blo gales Sun night and by
sunrise Monday should diminish to 20 knots or less and remain that
way into Tue.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...Rolfson
AVIATION...JP
MARINE...Voss
Area Forecast Discussion
National Weather Service Shreveport LA
811 PM CDT Thu Oct 3 2019
.UPDATE...
True cold front late this evening was located across S OK into N
AR but a prefrontal trough has made good progress into our region
and this combined with ample lift from an upper level disturbance
across SE TX and abundant instability from daytime heating
resulted in scattered to numerous thunderstorms earlier today and
we are still dealing with the aftermath this convection at this
late hour. A large outflow boundary exists from SW AR into NE TX
with convection continuing to develop/propagate to the west and
northwest in its wake. Coverage is significant enough such that
will increase pops for the remainder of the evening hours across
portions of NE TX/SW AR and NW LA. Latest HRRR has come in
suggesting that we may not see more than isolated coverage at best
late tonight through the predawn hours on Friday so lowered pops
to slight chance variety after midnight.
Overnight low temperatures are in good shape with upper 60s to
lower 70s areawide as the true cold front to our north should
slowly backdoor itself to near the I-20 corridor of NE LA by 12z
Fri.
Update out shortly...13.
&&
.PREV DISCUSSION... /issued 537 PM CDT Thu Oct 3 2019/
AVIATION...
Scattered to numerous showers and thunderstorms continue near or
in the vicinity of most of our terminal locations late this
afternoon. Will therefore prevail VCTS at all terminals through
much of the evening. E TX terminals will prevail VCTS through 04z
as latest HRRR shows convection through the remainder of the night
remaining mostly east of our NE TX terminal locations. Therefore
for the TXK/ELD/SHV and MLU terminals, these high res solutions
suggest that convective coverage is significant enough to keep
VCTS going through much of the night. At these terminal locations,
mentioned VCTS through 04/08z with coverage likely beginning to
diminish after that hour.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 72 90 68 91 / 60 30 0 0
MLU 72 90 67 93 / 30 20 10 0
DEQ 69 83 63 88 / 30 20 0 0
TXK 70 85 63 89 / 50 20 0 0
ELD 68 85 63 91 / 60 20 0 0
TYR 72 89 68 91 / 60 30 10 0
GGG 71 89 67 89 / 60 30 0 0
LFK 71 91 69 89 / 30 20 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
13/13
Area Forecast Discussion
National Weather Service Tulsa OK
948 PM CDT Thu Oct 3 2019
.DISCUSSION...
Cold front has cleared the forecast area this evening, and will
remove the evening pops in southeast Oklahoma and west central
Arkansas. Cloudiness across the far northwest part of the forecast
area is likely to expand some to the southeast overnight, and the
latest HRRR does show a few showers developing prior to sunrise.
Thus will leave the low pops as is for late tonight in parts of
northeast Oklahoma. Have also made just a couple minor
adjustments to low temperatures tonight.
Update on the way.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...20
LONG TERM....05
PLATE
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
535 PM MDT Thu Oct 3 2019
.DISCUSSION...(This Evening Through Thursday)
Issued at 218 PM MDT Thu Oct 3 2019
Upper-level ridging was over the CWA per water vapor images and
the RAP model analysis. Surface high pressure over the eastern
Dakotas and a trough over central MT/WY has resulted in a
tightening pressure gradient across the CWA, with correspondingly
gusty south winds.
As an upper-level trough over the West Coast approaches the CWA
tonight and Friday, a strong low-level jet stream (up to 50 kt) will
develop over the CWA. This will allow for continued gusty south
winds over northeastern WY and western SD tonight, and over the SD
plains on Friday (where marginal wind advisory conditions may be
met). Conditions are not ideal for extreme downslope winds over
the northern foothills tonight, but it is something that bears
watching.
A narrow sliver of MLCAPE from 500-1000 J/kg will develop over
northeastern WY Friday afternoon, which when combined with the
strong Q-G forcing, a dry boundary layer, and strong deep layer
shear, should be conducive to a few high wind-producing
thunderstorms. The upper trough will swing through the CWA Friday
night, bringing scattered showers and thunderstorms, along with
some snow to the Black Hills and northeastern WY (amounts 1 inch
or less).
Strong northwest winds will develop late Friday night and Saturday
behind the cold front as 850-mb winds reach 50 kt along with modest
cold advection. Sunday will be less windy but still cool as
northwest flow aloft continues.
Model ensembles support upper ridging Monday and Tuesday, leading to
above-average temperatures and dry weather. The next cold front is
slated to move through the CWA Tuesday night, with reasonably good
agreement among the ensembles on the timing.
&&
.AVIATION...(For the 00Z TAFS Through 00Z Friday Evening)
Issued At 532 PM MDT Thu Oct 3 2019
VFR conditions are expected through Friday afternoon. A
developing low level jet will low level wind shear to much of the
area tonight. Gusty south winds are expected on Friday. A cold
front will move into northeast Wyoming late Friday afternoon with
a chance of showers and thunderstorms.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION...Bunkers
AVIATION...7