Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/28/21
Area Forecast Discussion
National Weather Service Corpus Christi TX
615 PM CDT Wed Oct 27 2021
.AVIATION...
VFR conditions will prevail across S TX through the TAF period.
The main concern will be winds and low level wind shear. Strong
gusty west to northwest surface winds this afternoon, will
decrease through the evening hours becoming light tonight.
However, models show winds above the surface increasing to around
35-40 knots overnight. This will lead to LLWS late tonight with
best chance of LLWS being across the VCT TAF site where models
show the strongest low level winds. After sunrise, winds will
begin to mix to the surface ending the LLWS, but increasing
surface winds with gusts to around 25 knots possible through the
day Thursday. Winds are expected to decrease late Thursday
afternoon.
&&
.PREV DISCUSSION... /Issued 426 PM CDT Wed Oct 27 2021/
SHORT TERM (Tonight through Thursday Night)...
An intense/high-amplitude upper disturbance over the central/southern
Plains/Texas is expected to move slowly eastward during the
period (NAM/GFS/ECMWF deterministic). The associated cold front
has already moved offshore (LAPS analyses). Significantly cooler
and drier conditions are expected during the period, with lows in
the mid 50s/lower 60s tonight, upper 70s/mid 80s Thursday, and
lower/mid 50s Thursday night (SREF ensemble mean/NBM).
LONG TERM (Friday through Wednesday)...
At the start of the long term period, South Texas will be on the
backside of the deep trough with a strong gradient. Winds will
remain elevated but will die down Friday evening. After that, the
synoptic flow changes to a quasi-zonal flow for the remainder of the
period.
The main story will be the cooler night-time temperatures with lows
in the 40s up north Friday night but mostly ranging in the 50s to
60s across the region. Daytime highs will range in the 80s each day.
As onshore flow returns Sunday, low level moisture will steadily
increase, with PWAT`s reaching to near 1.3" by around Wednesday.
Mainly clear skies this weekend will give way to increasing clouds
as mid to upper level moisture attempts to creep back in over the
area.
Another front may impact South Texas toward the end of next week
associated with a broad area of troughing stretching down from near
the Great Lakes region. Currently models suggest a weak frontal
boundary making to our CWA between a Thursday to Friday timeframe.
Due to uncertainty in timing/strength of the front between models,
have opted to stick with the NBM for temps for days 5-8 however, I
suspect this may be a little cold biased due to influence from
current initialization factors and considering a weaker front. May
adjust for future runs as the synoptic pattern becomes more clear.
MARINE...
Strong momentum aloft, associated with the foregoing intense upper
system, expected to mix toward the surface tonight and Thursday.
Deterministic runs predict a dry-adiabatic environment below
around 750 mb over the coastal waters during that period.
Anticipate Gale conditions 06z Thursday-06z Friday over the
coastal waters, the time frame where the the NAM, GFS. and RAP
predict 40kt wind at 850-mb, much of which should mix toward the
surface. Thus, issued a Gale Warning for the coastal waters for
that time period. The only caveat is probabilistic output from the
SREF that suggest winds below gale. Nevertheless, confident in
gale conditions given expected vertical mixing.
Flow will then weaken to moderate to strong by late Friday and then
weak to moderate by Saturday before turning onshore by early Sunday.
Small Craft Advisory conditions will continue through Friday night.
Dry conditions are expected to continue heading into next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 58 82 54 80 52 / 0 0 0 0 0
Victoria 55 78 50 75 46 / 0 0 0 0 0
Laredo 56 86 54 85 55 / 0 0 0 0 0
Alice 55 85 52 82 50 / 0 0 0 0 0
Rockport 62 83 57 79 56 / 0 0 0 0 0
Cotulla 53 86 52 85 52 / 0 0 0 0 0
Kingsville 56 83 52 81 51 / 0 0 0 0 0
Navy Corpus 64 82 62 78 61 / 0 0 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Red Flag Warning until 7 PM CDT this evening For the following
zones: Bee...Coastal Kleberg...Coastal Nueces...Coastal San
Patricio...Duval...Inland Kleberg...Inland Nueces...Inland
San Patricio...Jim Wells...Kleberg Islands...La Salle...
Live Oak...McMullen...Nueces Islands...Webb.
GM...Small Craft Advisory until 1 AM CDT Thursday For the following
zones: Coastal waters from Baffin Bay to Port Aransas out
20 NM...Coastal waters from Port Aransas to Matagorda Ship
Channel out 20 NM...Waters from Baffin Bay to Port Aransas
from 20 to 60 NM...Waters from Port Aransas to Matagorda
Ship Channel from 20 to 60 NM.
Small Craft Advisory from 1 AM to 4 AM CDT Friday For the
following zones: Coastal waters from Baffin Bay to Port
Aransas out 20 NM...Coastal waters from Port Aransas to
Matagorda Ship Channel out 20 NM...Waters from Baffin Bay
to Port Aransas from 20 to 60 NM...Waters from Port Aransas
to Matagorda Ship Channel from 20 to 60 NM.
Gale Warning from 1 AM Thursday to 1 AM CDT Friday For the
following zones: Coastal waters from Baffin Bay to Port
Aransas out 20 NM...Coastal waters from Port Aransas to
Matagorda Ship Channel out 20 NM...Waters from Baffin Bay
to Port Aransas from 20 to 60 NM...Waters from Port Aransas
to Matagorda Ship Channel from 20 to 60 NM.
Small Craft Advisory until 1 AM CDT Friday For the following
zones: Bays and Waterways from Baffin Bay to Port Aransas...
Bays and Waterways from Port Aransas to Port O`Connor.
&&
$$
TE/81...AVIATION
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
719 PM CDT Wed Oct 27 2021
.UPDATE...
Winds have generally decreased below 20 mph across South Central
Texas, so we have allowed the Wind Advisory to expire. We expect
winds to increase again Thursday morning and continue through the
afternoon across the eastern part of the CWA. Speeds will reach 20
to 30 mph with gusts up to 40 mph. We have issued another Wind
Advisory for Thursday from 10 AM until 7 PM for most of the area from
Llano County to Lavaca County.
&&
.PREV DISCUSSION... /ISSUED 635 PM CDT Wed Oct 27 2021/
AVIATION...
All terminals will have clear skies through this TAF period.
Northwesterly winds will decrease to less than 10 kts around sunset
this evening. Strong, gusty winds will redevelop Thursday morning
with sustained speeds around 15 kts and gusts to 25 kts. At AUS winds
will increase to sustained around 20 kts with gusts to 35 kts during
the afternoon.
PREV DISCUSSION... /ISSUED 507 PM CDT Wed Oct 27 2021/
UPDATE...
Winds continue to gust in the 30s across much of South Central Texas.
It`s taking a bit longer than we had previously anticipated for them
to drop off. We have extended the Wind Advisory until 7 pm.
PREV DISCUSSION... /ISSUED 240 PM CDT Wed Oct 27 2021/
SHORT TERM (Tonight through Thursday Night)...
Early this afternoon, satellite imagery and RAP analysis depict the
base of a sharp 500 mb trough beginning to exit our area east of I-
35. Convection cleared the area earlier this morning and dry air has
rushed in behind the front as advertised. NW winds at 15-25 mph and
occasionally near 30 mph along the Rio Grande have gusted to 35-45
mph in many locations today, and a Wind Advisory will continue
through 5pm for much of the region, including Atascosa, Bexar,
Comal, And Guadalupe which were recently added. In addition, the Red
Flag Warning continues through 7pm as RH as fallen into the teens
and 20s in tandem with these gusty winds. Atascosa and Medina
Counties were added today where conditions are a touch drier than
previous forecasts suggested.
Temperatures are MUCH more comfortable today, in the 70s to lower
80s. Tonight, winds will drop off pretty quickly to 5-15 mph for
most locations, and lows should dip into the low to mid 50s. A few
low-lying spots in the Hill Country could see some mid to upper 40s
around sunrise Thursday. The pressure gradient will shift eastward
on Thursday but remain strong as a sfc low deepens over MO/AR late
tonight and becomes nearly vertically stacked with the H5 low.
Anticipating breezy to windy conditions once again, highest from
Austin north and eastward where gusts may again exceed 40 mph at
times. Another Wind Advisory may be needed for a few counties,
however with one already in effect today we will hold off on that
decision until this evening or tonight. RH will again dip into the
teens west where winds will be lower, and in the 20s east. Elevated
to perhaps near critical fire weather conditions are expected once
again, primarily for areas that received little if any rainfall
earlier today out in the Winter Garden region. Thursday night lows
should be a couple degrees cooler than tonight, mainly in the mid
40s to lower 50s.
LONG TERM (Friday through Wednesday)...
Friday into the start of the weekend will remain fair and very
comfortable as the region remains under a dry northwesterly flow
aloft and high pressure at the surface. After the cool morning
start, the dry air and sunshine allow for temperatures to climb
upwards into the 70s and 80s. Friday night into early Saturday
morning may see the coolest temperatures this week as result of
clear skies and lighter winds at the surface. The surface high
slides eastward through Saturday, which should turn the surface
winds out of the southeast. It allows for a modest but gradual
moisture return and warm up across the region during the latter
portion of the weekend into early next week. Mid to high level
clouds also likely increase as the upper level flow becomes more
zonal.
Forecast confidence is lower than average for early to middle of
next week regarding the timing of fronts and the passage of weak
disturbances within the broad westerly flow aloft. While little
weaker on the 12Z run compared to the previous 06Z run, the GFS
remains the most aggressive on advancing a surface front towards
portions of the Hill Country on Monday. It also tries to generate
light qpf from showers across portions of the area. In contrast,
majority of the model blends and the ECM/CMC are much slower with
this pattern change and hold the surface front well to the north
until later in the week. Like the previous forecast shift, I will
continue to trend the forecast closer to the NBM (National Blend
Model) which favors a continued mainly dry forecast featuring
seasonably mild temperatures through Tuesday. Slight chances for
showers then enter the forecast on Wednesday when the NBM does
highlight the arrival of that next front.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 55 75 52 74 48 / 0 0 0 0 0
Austin Bergstrom Intl Airport 53 76 50 74 43 / 0 0 0 0 0
New Braunfels Muni Airport 52 79 49 76 45 / 0 0 0 0 0
Burnet Muni Airport 53 74 49 72 46 / 0 0 0 0 0
Del Rio Intl Airport 55 82 53 82 52 / 0 0 0 0 0
Georgetown Muni Airport 54 74 50 73 44 / 0 0 0 0 0
Hondo Muni Airport 51 81 48 79 45 / 0 0 0 0 0
San Marcos Muni Airport 52 77 49 74 44 / 0 0 0 0 0
La Grange - Fayette Regional 55 77 51 74 46 / 0 0 0 0 0
San Antonio Intl Airport 56 77 52 76 49 / 0 0 0 0 0
Stinson Muni Airport 57 81 53 78 48 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 10 AM to 7 PM CDT Thursday for Bastrop-Burnet-
Fayette-Lavaca-Lee-Llano-Travis-Williamson.
&&
$$
Short-Term/Aviation...05
Long-Term...Treadway
Area Forecast Discussion
National Weather Service Green Bay WI
1010 PM CDT Wed Oct 27 2021
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Thursday
Issued at 349 PM CDT Wed Oct 27 2021
The latest RAP analysis and satellite/radar imagery show eastern
Wisconsin positioned between high pressure over the lower Michigan
and low pressure over the central Plains. Low level southeast flow
out of the surface high continues over eastern WI. Lake-850mb temp
difference is running about 10-12C, which has contributed to
broken to overcast skies over much of northeast Wisconsin early
this afternoon. Meanwhile, mid and high clouds over the Plains have
made very little progress eastward ahead of the low pressure
system due to very dry air in the 850-625mb layer. As low pressure
moves east and low level east flow continues, cloud cover and
light precip chances are the main forecast concerns.
Tonight...Low pressure will continue to track east into the
northern Mississippi Valley by late tonight. Under a sharp ridge
axis, very dry air above the inversion will continue to block
deeper moisture ahead of the low from moving into eastern WI. This
will keep widespread rainfall along and west of the Mississippi
River. Although Lake-850mb temp difference may moderate some, the
temp difference will remain near 10C through the night. Combined
with moist, onshore flow with a large area of stratus over
Michigan, should see low clouds spread across northeast and into
north-central WI late this evening into overnight. Some saturation
above the inversion appears possible, which will lead to a chance
of light rain and drizzle. Have made only minor changes to precip
chances from the previous forecast, which will increase after
midnight. Temps will range from the upper 30s to middle 40s.
Thursday...With onshore flow continuing, a weak surface trough
remains expected to move from east to west across northeast WI.
Light rain/drizzle may be more concentrated along this trough,
particularly during the morning. Some moisture from the cyclone
over the mid-Mississippi Valley will try to spread northeast into
Wisconsin in the afternoon. Dry air will likely hold off precip
into central WI until mid or late afternoon. Highs will only
range from the low to mid 50s.
.LONG TERM...Thursday Night Through Wednesday
Issued at 349 PM CDT Wed Oct 27 2021
The main highlights from this forecast period revolve around the
continuation of light precipitation Thursday night into Friday, at
or slightly above normal temperatures sticking around through the
weekend, and temperatures falling below normal for early next week.
Thursday night through Friday...An upper-level trough will continue
to split into two pieces as it approaches from the west Thursday
night. The southern piece will become stronger with a closed low,
which will weaken the northern piece as they both advance east
Thursday night. However, lingering moisture from the northern piece
will combine with the increasing moisture from the southern piece
and spread light precipitation across the forecast area Thursday
evening/night. The precipitation chances will decrease from
northwest to southeast into Friday as the upper-level flow splits
completely and dry air, associated with an upper-level ridge, begins
to move into the Upper Mississippi Valley. Meanwhile, the forecast
area will be on the northwest side of the surface low and closed low
on Friday, which will create gusty northeast surface winds.
Rest of the extended...The previously mentioned upper-level ridge
will build across the region Friday night, and stick around through
at least Saturday evening. Above normal temperatures are expected
for Saturday as a result with readings climbing into the middle to
upper 50s. Model guidance has fallen out of agreement with the
timing of the trailing cold front/upper-level trough (Saturday night
or during the day on Sunday). Regardless, temperatures will fall
below normal behind this cold front/trough from the presence of
cooler Canadian air spreading across the region. There does appear
to be a few opportunities for lake-effect showers along the WI/Upper
MI border during this time as well.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1003 PM CDT Wed Oct 27 2021
MVFR ceilings covered the forecast area late this evening. Persistent
southeast to east winds off Lake Michigan and upslope flow will
cause ceilings to lower even more overnight, with IFR conditions
expected in many areas later tonight. Periods of drizzle/fog with
MVFR/IFR vsbys may also form overnight into Thursday morning.
Light rain over MN will continue to edge eastward, reaching
central and parts of north central WI by late afternoon, and all
but far northeast Wisconsin by the end of the TAF period.
Modest improvement in ceilings and vsbys are possible in eastern
WI Thursday afternoon and evening, before deteriorating again
late in the TAF period. Conditions may briefly return to VFR in
the lakeshore areas in the late afternoon and early evening.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Hykin
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1000 PM EDT Wed Oct 27 2021
.SYNOPSIS...
A cold front will lift across our area from the southwest on
Thursday and bring widespread rainfall for Thursday and Thursday
night, with clouds and rain chances lingering into Saturday. Drying
high pressure will eventually spread back over the Southeast on
Sunday and persist through early next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 1000 PM EDT Wednesday: The widespread coverage of cirrus
associated with the incoming frontal system to the west is now
entering the western fringes of the CFWA. Still no major changes to
the forecast. Low temperatures could be somewhat tricky depending on
how fast the deck of cirrus moves in and how much radiational
cooling can take place before the arrival of the upper-level
clouds, especially in the eastern zones.
Otherwise, heights are progged to begin falling in earnest between
03Z and 06Z tonight, as deep troughing pushes out of the southern
Plains and evolves into a cutoff low over the western Tennessee
Valley. An associated surface low will track across the Ozarks
tonight, with attendant cold front in tow. Concurrently, profiles
across the Carolinas should begin to moisten from the top down, so
high-level clouds should grow quite a bit thicker overnight. A
modest 60-70kt jet streak should push across the deep south by
morning, and 250mb maps depict ripples of upper divergence flowing
across the southern Appalachians and SC Upstate after dawn. This
feature has been fairly consistent across the last few runs of the
RAP and ARW, though it remains conspicuously absent from the
NAMnest, which keeps the decent forcing to our south. DPVA starts
to ramp up by morning as ripples of vort energy start to enter our
forecast area out of the southwest; the ARW most notably picks up on
a subtle embedded shortwave that produces a whole extra lobe of vort
energy ahead of the rest. This acts to enhance midlevel lift
earlier than the other CAMs...and in conjunction with the upper
support provided by the jet streak, results in an earlier onset of
precip across the mountains and eastern foothills as early as
sunrise.
Generally speaking, cloud cover and PoPs should increase throughout
the morning and afternoon Thursday, with categorical PoPs in
the forecast by 20Z, when even the slowest-evolving FV3 depicts
widespread showers. A band of elevated PWATs should push through
by mid- to late-afternoon, accompanied by a 30-40kt LLJ depicted
on 850mb maps on several of the CAMs. Consequently, despite
very limited instability across the board, it`s likely we will
see widespread showers and perhaps even an isolated thunderstorm
Thursday night. Given dry antecedent conditions, and a fairly
quick-moving system, the threat for heavy rain remains marginal,
though still large enough to note here. Latest storm total QPF
comes in at about 1" across much of the Piedmont.
A few of the CAMs are also honing in on gusty winds along the
spine of the Appalachians starting around sunrise Friday, when good
mixing will allow those strong 850mb winds to easily drop down to
the surface. For now, it doesn`t appear that we`ll have widespread
advisory-criteria winds. Several of the CAMs now also depict a
weak secondary zone of upper divergence arriving in the predawn
hours, just as a slug of midlevel CAA steepens lapse rates enough
to produce a few hundred Joules of CAPE. While LCLs are on the
high side, this modest instability paired with the aforementioned
upper enhancement is leading several of the CAMs toward another
round of showers just before dawn Friday morning.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
As of 100 PM Wed: Upper low will move across Middle and East
Tennessee over the course of Friday, becoming centered the CWA early
Saturday before lifting out to the north. Somewhat chilly, some would
say dreary weather will prevail for the short term as a result. Temps
will by and large be below normal. This is particularly true in the
upper Savannah Valley, owing to the warmer normals there.
With the occlusion process continuing and the frontal zone pushing
farther away from the CWA thru Friday morning, CAA will dominate in
the low levels; deep moisture will wrap around the low and advect
back in during the day. At the same time, lapse rates generally will
increase, but on account of the moist profiles they don`t become that
exciting. SB- or MU-CAPE values are progged to be small. The
FV3-based HiRes Window and 3km NAM now go out through Friday and
depict bands of scattered showers rotating across the CWA, likely
forced by lobes of vorticity rounding the low. Though weak simulated
reflectivity suggests little chance of thunder or small hail,
isolated instances of either would be characteristic of the setup.
Upstream of the upper low will be a sharp ridge over the Plains. By
Friday night, warmer air is depicted as wrapping around the southern
flank of the low, which looks to improve 700-500mb lapse rates, if
not those in lower layers. Flow will be more westerly across the
mountains by that time due to the progress of the low, so a likely
PoP will persist overnight nearer the TN/NC border. The same elements
of the pattern persist through Saturday. There may be a marginal
boost due to whatever diurnal warming we can eke out with abundant
cloud cover, which may improve the near-sfc lapse rates. NAM/GFS
develop very little omega across the Piedmont, even then. Will allow
PoPs to rebound somewhat during the day but retain the NW-SE
gradient.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
As of 200 PM Wed: Heights will rise Saturday afternoon as low departs
and is replaced by an upper ridge. Though the contours appear to
flatten thru Sunday across the Southern states, heights steadily rise
as the dry sfc high modifies. Low-level moisture does persist in the
continuing NW flow across the mountains, resulting in a slow decline
in PoPs Saturday night, and enough cloud cover to impact temps a
little there on Sunday. Temps should climb back to normal or even a
little above for the Piedmont. Clearer skies will allow better
radiation the following night, making Monday morning our next
potential mountain frost event. A freeze is not expected perhaps
aside from a couple of isolated spots. The ridge axis will shift
offshore Monday as a broad trough digs across the northern Plains and
Midwest, but dry weather and near or slightly above-normal temps will
continue thru the end of the period. A cold front should be pushed in
our direction by the trough in the middle to late part of next week,
but most likely not until late Wed or Thu, so we will keep PoPs below
slight-chance thru the end of the period.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: VFR conditions should prevail at all sites
into tonight, at which point increasing upper-level moisture should
gradually increase cloud cover. Sites will develop initially-VFR
CIGs overnight, as widespread cirrus is beginning to filter in from
the west, and as profiles become saturated by dawn or the first part
of Thursday morning, CIGs will drop to at least MVFR restrictions
between 12Z and 15Z. Have introduced VCSH to most sites starting
before noon, then all sites drop to prevailing -SHRA with MVFR CIGs
and VSBYs by the afternoon. IFR restrictions will build in Thursday
afternoon and evening as the vertical column becomes fully saturated
at this point and will begin to lower CIGs and VSBYs.
Outlook: A brief lull in activity the second half of Friday will be
quickly followed by a return to unsettled conditions. Active weather
will persist through Saturday, after which Sunday and Monday are
expected to calm down.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...CAC/MPR
SHORT TERM...Wimberley
LONG TERM...Wimberley
AVIATION...CAC/MPR
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1107 PM EDT Wed Oct 27 2021
.SYNOPSIS...
A strong nor`easter will gradually shift south away from the
southern New England coastline tonight. Drying along with
diminishing winds are expected tonight. Quieter weather is then
expected for both Thursday and Friday before another storm
system approaches from the south this weekend which may bring
another bout of heavy rain and wind.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Update...Stratocu remains more or less stationary across parts
of W central ME at this hour. It will likely continue a slow
bleed SW thru the night before clearing near dawn. Otherwise the
winds are a little gustier near the coast...closer to the
center of the low pressure...as CAA steepens lapse rates a
little. I have bumped these gusts up while leaving sustained
winds as is...using a blend of the latest HRRR guidance.
Previous discussion...Low pressure continues to drift further
from the New England coast at this hour, decreasing the coverage
of gusty winds and precipitation over the region.
Through tonight, rain will come to an end; slowly breaking up
and moving off the coast. There was a decent convergence band
oriented along the ME coast through the afternoon hours as air
forced in by high pres combed through the higher terrain. The
strong coastal storm is resilient, not backing away too quick
from this influence. These showers have greatly decreased in
coverage and intensity over the past hour. While sun has broken
out in patches, some clouds may fill back in overnight as it
remains a bit breezy.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A beautiful late fall day is set for Thurs. Dry conditions with
a bit of a north breeze will remain, but clouds will decrease in
coverage through the day.
The biggest takeaway Thursday will be overnight as cold
temperatures trickle into the region. Aided by the northerly
flow ahead of high pres, winds will lighten and allow for CAA to
be amplified by rad cooling, particularly in the mtn valleys.
Areas of frost will likely creep into the foothills, with patchy
frost reaching towards the coast in the coolest spots.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
We`ll start out the extended portion of the forecast on Friday,
a day that will feature fair weather as high pressure will be in
control over New England. However, things begin to change rather
quickly Friday night as a closed low moves in from the west.
Latest deterministic and ensemble guidance are in reasonable
agreement with the track and timing of the closed low. As the
low moves eastward, a warm front will sharpen up just to our
south. As this occurs, a +1 to +2 sigma southerly low level jet
will develop and overrun the front as PWATS increase. The result
will likely be a period of heavy rain Saturday into Saturday
night. It`s tough to nail down QPF at this point, but a 12 hour
period delivering 1-2 inches of rain looks very reasonable given
the kinematics, dynamics, and moisture availability at play.
We`ll have to watch for mesoscale factors that could allow for a
little more rain that that, such as upsloping into the Whites as
well as any coastal front enhancement. The good news is that
the system as a whole continues to chug along and will highly
likely not be a multi- day event. Therefore, the rainfall should
be manageable but we`ll have to keep an eye on trends.
As far as wind potential with this weekend system goes, forecast
soundings show quite an inverted low level air mass most
locations which should keep the 50 kt LLJ at bay for the most
part. The exception could be in the immediate coast where
onshore easterly winds may become quite gusty for awhile, but
likely below advisory criteria. However, will certainly continue
to watch trends.
Thereafter, the rain looks to clear out Sunday with a few
showers remaining. Afternoon mixing should allow temperatures to
dance around the 60 degree mark.
Early next week looks to feature fair weather.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Short Term...Most sites remain VFR tonight, with the exception
of some MVFR cigs in southern NH. N winds remain gusty
overnight and Thursday, but lighter than Wed. VFR cigs expected
Thurs and Thurs night.
Long Term...VFR conditions are likely through Friday. The next
frontal system brings rain, lower ceilings, and the potential
for coastal winds this weekend, mainly Saturday and Saturday
night. LLWS will be possible.
&&
.MARINE...
Short Term...Gale winds continue tonight, with the bays falling
below Gale criteria in the morning. SCAs will be needed for the
waters once winds slacken late tonight as waves remain elevated
through Thurs night, becoming 4 to 6 ft.
Long Term...The next frontal system brings another round of
strong east to southeast winds, potentially gale force, this
weekend. Have 10 foot waves forecasted for Saturday at this
time for the ocean waters.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Gale Warning until 4 AM EDT Thursday for ANZ150>154.
&&
$$
NEAR TERM...Legro
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 321 PM CDT Wed Oct 27 2021
Today and Tomorrow:
Rain showers are currently ongoing across the forecast area. As of
2 pm, radar estimates a majority of the area has observed at least
half an inch. The highest estimate so far appears to be in
southwest Saline county near Cordova with 2 inches. Precipitation
is expect to persist for quite some time yet. Rain will slowly
dissipate from west to east. Areas west of a line from Wayne to
Lincoln should see precipitation come to an end around midnight.
Southeast Nebraska and southwest Iowa could see rain continue
until 6 am tomorrow. Overall, another 1 to 1.5 inches of rain can
be expected, with the highest amounts in southeast Nebraska and
southwest Iowa. Flash flooding potential is low as the
precipitation should fall over a long enough duration of time to
mitigate the risk.
In addition to rain, a cold front is current moving through the
area. As of 2 pm, the front is located from Wayne down through
Fairbury. Winds on the cold side of the front are from the
northeast at around 15 mph with gusts up to 20 mph. Wind speeds
will increase late this evening after sunset, particularly across
eastern Nebraska and western Iowa due to tightening of the surface
gradient and momentum transfer. The forecast is for wind gusts up
to 35 mph. However, this may be an underestimate. HRRR and RAP
data show a potential for 45 mph gusts.
Wind speeds are expected to be even stronger tomorrow. Winds will
maintain some some strength overnight, but will strengthen after
6 am and persist into the evening. Peak sustained winds will be
from the northwest at 20 to 25 mph with gusts up to 45 mph. Winds
will begin to weaken in the evening as the upper level low
finally moves off to the east.
Friday through Tuesday:
Friday and Saturday are forecast to be calm, dry days as weak
ridging builds over the central Plains. Highs Friday will be in
the upper 50s and highs Saturday will be in the low to mid 60s. Of
note, Saturday morning could finally see freezing temperatures
reach southeast Nebraska. Lows will be in the low to mid 30s.
The warm up Saturday will be brief as a strong cold front is
forecast to move into the area late Saturday night and clear the
area by Sunday morning. High pressure building behind the front
will allow for cold air to flow south from Canada resulting in the
coldest temperatures of the seasons so far. The Climate
Prediction Center forecast calls for a 60-70% chance for below
temperatures in the 6 to 10 day range. This is reflected in the
temperature forecast next week with high temperature likely not
reaching 50 degrees in the early part of the week. Morning lows
are forecast to drop below freezing for the entire forecast area.
Precipitation chances are low with the ECMWF having the highest
probabilities. Though, there is not much agreement in the medium
range models.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 624 PM CDT Wed Oct 27 2021
Rain, heavy at times, has been driving visibility occasionally
into IFR category.Cigs, too, have dipped into that category.
Expect those conditions to linger through about 03Z before seeing
improvements based on the diminishing rain. This trend will
continue through about 12Z when rain becomes unlikelier from west
to east.
Some low level wind shear of about 45 knots at 2000 feet is
forecast for OMA between 07 and 18Z. It`ll start a bit later at
LNK and won`t reach mentionable category at OFK. Surface winds
will be gusting up to 30 knots out of the NNW after 03Z and last
through the TAF period.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Fajman
AVIATION...Nicolaisen